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In this work, an air-cooled, single effect solar-driven absorption system is being evaluated from the point of view of 1 st and 2 nd thermodynamic principles for two different applications: absorption chiller and heat pump. One of the most widely used working pairs, LiBr-H 2 O, is applied in this study due to its high performance in the absorption cycle. Their performance is compared with another working pair Carrol-H 2 O (Carrol contains LiBr and EG -Ethylene glycol- with a mass ratio of 4.5:1). The Carrol solution has the advantage of reducing the crystallization risk at the high concentration solution which enters the absorber. The numerical modelling was implemented on a modular object-oriented simulation platform (NEST platform tool), which allows linking different components, considered objects. In the simulations performed, the heat source temperature in the system is in the range of 70-90 ∘ C, and the inlet temperature at evaporator secondary circuit at chiller application is fixed in two values, 9 ∘ C and 14 ∘ C, and for heat pump application in 0 ∘ C and -5 ∘ C. Moreover, EG is added to the evaporator at heat pump application to prevent the refrigerant water from freezing below zero. The studied mass concentration range of EG of 10-40%. The result shows the C O P of an absorption chiller and heat pump are around 0.7 and 1.6, respectively, and the C O P EX values are 0.2-0.6 at chiller application and 0.5-1.5 at heat pump application. When compared with LiBr system, Carrol system has about 6.4% higher C O P , about 6.3% higher C O P EX , and a decrease of about 19% of cooling capacity. In the heat pump application, the heat source temperature should be lower than 90 ∘ C, and EG concentration at evaporator has been chosen as 30% as an optimal value. According to the operation condition, this EG concentration has been determined to avoid freezing in the evaporator in the studied working range. However, too much EG significantly decreases the pressure in the evaporator and increases the viscosity, hence will increase the maintenance of equipment as more vacuum tightness is required.

Power factor is the ratio between active power (W) and apparent power (VA). In an electrical installation, the quality of electric power can be said to be good if the value of the power factor is above a predetermined standard of 0.85 according to the Minister (ESDM) Number 30 of 2012 [1]. From the research that has been done at the Blitar Square Shopping Center, it was found that the power factor value is still below the standard with an average value of 0.711. With the low power factor value, this shopping center gets a penalty from PT. PLN (Persero) due to the use of reactive power. Therefore, it is necessary to make efforts to improve the power factor by installing a capacitor bank. The installation of this capacitor bank is expected to be able to increase the power factor value with a power factor target of 0.98 and reduce the charge for reactive power usage penalties. The calculation results show that global compensation requires 12 capacitor banks with a rating of 10.4 kVAR, while sectoral compensation on the chiller load panel requires 7 capacitor banks with a rating of 10.4 kVAR and the foodmart load panel requires a capacitor bank with a rating of 10. 4 kVAR is 6 pieces. In simulating the installation of a capacitor bank using the ETAP application, it is known that the installation of a capacitor bank can increase the power factor value. In addition, the installation of a capacitor bank also results in an increase in the voltage value in the system, this voltage increase is still below the permissible standard of ± 5%. The simulation of installing a capacitor bank on global compensation can improve the power factor value from 72.99% to 96.97%, with a voltage increase of 0.479% from the initial value of 397 V to 398.9 V, and a decrease in the current value of 24.645% from the initial value. 330.7 A to 249.2 A. While the simulation of installing a capacitor bank in sectoral compensation can improve the power factor value from 72.99% to 93.57%, with a voltage increase of 0.401% from the initial value of 397 V to 398.6 V , and a decrease in the value of current by 21.593% from the initial value of 330.7 A to 258.1 A. The cost of installing a capacitor bank in global compensation was Rp. 189,897,500 while the sectoral compensation is Rp. 211.305.600. It can be concluded that the installation of a capacitor bank using the global compensation method is more effective.

A CCHP is modeled here, which is operated based on thermal energy provision because the target consumer demands more heat and cooling than electricity. The main components of the CCHP system are a PEMFC as the main generator, absorption chiller, electric chiller, and auxiliary boiler. The fuel consumption, cost, and carbon release improvements compared to a separated generation system (SGS) are maximized in this system using the proposed modified mayfly algorithm. The system design and operation are optimized in two different stages. A hotel building has been chosen as the case study to demonstrate the effectiveness of the proposed CCHP system and optimization in comparison to the traditional mayfly algorithm (MA) and genetic algorithm (GA). The proposed optimization algorithm has performed 8.15% and 10.06% better compared to MA and GA, respectively. It also reached its solution in far shorter time. The optimum size of PEMDC and share of auxiliary chiller (AC) in cooling provision is determined to be 548 kW and 43.1%, respectively. It is shown that improvement achieved by using the AC in the CCHP is increased by 23.21% compared to a CCHP without one. Furthermore, the AC make the improvement of CCHP more constant and robust to load variation. Moreover, the sensitivity of the optimum operation condition of the CCHP against the electricity and fuel price changes and share of the AC in supplying the cooling demand are studied to provide the system operators with the necessary tools needed to optimally handle price changes.

Solar cooling systems, specifically solar absorption cooling systems, are becoming an attractive subject since they are great alternatives to the conventional cooling systems which lead to high electrical consumption. In addition, this system can provide cooling without greenhouse gas emissions. Hence, many combinations of different components might be adopted to apply the solar absorption cooling system. This paper will discuss the absorption chiller working cycle, the absorption chiller working fluids, the solar collectors to be combined with solar cooling systems and the single-effect absorption chiller. Furthermore, the variation of the coefficient of performance, the solar fraction and the economic study will be discussed. The goal of this review is to present previous studies and analyze their results; highlight the environmental, energetic, and economic viability of such systems and tackle future challenges regarding solar absorption cooling system and discuss the application of this system on new climates and more specifically on Lebanon.

District heating and cooling are considered effective solutions to decarbonise the energy use in the building sector. The latest generation of district heating and cooling also increases the potential of integrating heat pumps and chillers in each building substation. The benefits of such integration are the reduction of network temperature and distribution losses; the recovery of waste heat through a bidirectional network; and the decentralised production of heating and cooling. Sizing the network depends mainly on the heat flows between connected buildings. The substation performance and technical installations determine these heat flows. We present in this paper Modelica-based simulations of two design cases for substations. The first design case involves installed heat pump, chiller, and circulation pumps. Alternatively, the second design enables the heat pump to provide direct cooling through a heat exchanger. The models for these installations were developed using the Modelica language to perform continuous-time simulations. The performance in each design case was evaluated in terms of seasonal coefficient of performance and total electric energy use. An analysis on a cluster of 11 buildings suggests that the addition of the direct cooling heat exchanger can save up to 10% of the total annual electric energy use. Additional savings can be achieved by optimising the building supply temperatures and the district network temperature.

District heat driven absorption chillers (AChs) contribute to a higher utilisation of the district heating network in summer and thus to a reduction of the relative heat losses. Due to higher investment but lower operating costs, AChs usually cover the base load, but compression chillers (CChs) are installed for peak load as well. For ACh and CCh, heat rejection is often realised via cooling towers (CTs). In addition, many systems provide the option of free cooling in winter by using the cooling towers to cover the cooling demand directly. Thus, absorption cooling (AC), compression cooling (CC) and free cooling (FC) represent three operating modes for cold generation in one overall refrigeration system. The concept of allocating base load and peak load is usually realised by activating CC when AC exceeds the capacity limit. FC is activated when the ambient temperature falls below a certain switchover value. In this study, extensive monitoring data from a large-scale field test (“Field test absorption chillers for CCHP systems”) are used to show that refrigeration systems controlled in such or similar ways have considerable potential to increase primary energy efficiency, even if the individual chillers are operated efficiently. Therefore, models are applied to the individual primary components (ACh, CCh, CT and auxiliary pumps). By using these models, thermal and/or electrical part-load efficiencies of AC, CC and FC and their specific dependencies on the ambient temperature and chilled water set temperature are calculated. Taking into account district heating and electricity primary energy factors allows to determine the operating mode with the lowest primary energy demand for each load condition measured in the field test within one year. The savings potential of 14% resulting from this example shows how promising the application of a model-based system control is compared to conventional strategies.

This article studies the economical, technical and environmental aspects of a third generation district heating (DH) network with absorption chillers installed at substation level in order to satisfy the cooling demands. This network solution hence takes advantage of the distribution facilities of existing DH systems. The study aims at evaluating the technical and environmental performances of this new district heating architecture, when sized and operated according to an economic objective using the Mixed Integer Linear Programming (MILP) optimization formalism. It is compared to the case where cooling demands are met using individual chillers. The paper first presents the production, distribution, demand and storage models. Regarding the demand side, different heating and cooling scenarios are studied by varying the proportions of residential and tertiary buildings. The model is fed in a second part with data from the French context. In particular, we rely on typical French weather conditions, thermal loads and energy costs. The analysis of the results focuses on the cooling part. It appears that the thermal network solution achieves on average a 3.6% reduction in the levelized cost of space cooling energy. In the worst case space cooling exergy efficiency goes through a 82% decrease. GHG emissions decrease on average by 7.7% thanks to the absence of leakage of refrigerant with high global warming potential. Overall, these emissions are low due to the low carbon content of French electricity.

An increase in gas turbine efficiency is possible by inlet air cooling in chillers converting a heat of exhaust gas into refrigeration. In traditional absorption lithium-bromide chillers of a simple cycle an inlet air can be cooled to 15°С. More decrease of turbine inlet air temperature and greater fuel saving accordingly is possible in refrigerant ejector chiller as a simple in design and cheap. The innovative turbine inlet air cooling (TIC) system with absorption chiller as a high-temperature and ejector chiller as a low-temperature stages for cooling air to 7 or 10 °C is proposed. Its application in temperate climate provides annual fuel saving by 1.5 to 2 times higher compared with traditional air cooling in absorption chiller to 15 °C. A novel universal method of analysing the efficiency of TIC system operation and rational designing has been developed. The method involves the simple numerical simulation based on real input data of site actual climatic conditions. The annual fuel saving is chosen as a primary criterion. The novelty of the methodological approach consists in replacing the current yearly changeable fuel reduction due to TIC by its hour-by-hour summation as an annual fuel saving. The increment of annual fuel saving referred to needed refrigeration capacity of TIC system is used as an indicator to select a design refrigeration capacity. A rational design refrigeration capacity determined by applying the novel methodology allows to decrease the TIC system sizes by 10 to 20% compared with traditional designing issuing from the peaked thermal load during a year. So far as it was developed analytically by introducing quite reasonable criterion indicator and based on the simple summation procedure the method is quite applicable for designing in power and energy.

According to the Sustainable Development Scenario, the power generated by concentrating solar systems will be multiplied by 12 times by 2030 and will achieve nearly 184 TWh. To make it possible it is necessary to combine the concentrating solar systems with other technologies such as photovoltaics, sorption chillers, Stirling engines, etc. The total efficiency of hybrid systems is significantly higher than standalone ones. This paper analyzes​ the possibility of upgrading the existing concentrating solar thermal system with two-focal points located in Cracow, Poland. So far, this installation was used only for water heating applications. To estimate the possibilities of upgrading this system, numerical simulations with the use of Ray Tracing methods and Computational Fluid Dynamics were provided. Data obtained from the ray-tracing analysis allowed to determine the distribution of irradiance for various locations of the receiver. The CFD methods enabled to find the dependencies between the initial parameters of the working fluid, irradiance distribution, and heat transfer efficiency. Obtained results allowed to conclude that it is possible to use generated heat (354 K) for absorption chiller purpose. Moreover, this system may be used for simultaneous heat and electricity production, but firstly some changes in receiver geometry should be introduced.

This paper proposes the performance improvement of the ejector refrigerator based water chiller (ejector-based chiller) by means of using different mixing chamber profiles. Two different ejector mixing chamber profiles are constructed which are based on the conventional method (CONV–ejector) and the constant rate of momentum change method (CRMC–ejector). With the different design methods, the ejectors have different flow areas along the ejector’s axis; however, they have identical ejector throat diameters of 9 mm. Both ejectors are equipped with two primary nozzles, and hence, they have the same ejector area ratio of 6.3 and 7.9, respectively. The refrigerator is powered by hot water at a temperature of 94–98 °C while the condenser is cooled by cooling water at 29–31 °C. The chilled water temperature (Tchill) under various cooling loads and COP is assessed. It is found that the CRMC–ejector produces a much lower chilled water temperature than the CONV–ejector at identical cooling load. The system COP can be increased by 27–63% via the CRMC–ejector. With the change in Thot, both ejectors produce identical Tchill; however, the CRMC–ejector still produces much lower Tchill at an identical cooling load. A larger primary nozzle throat yields a higher Tchill.

The paper presents an experimental investigation of a solar dish concentrating system with thermal collectors, along with a numerical investigation of a solar cooling installation based on such system by means of dynamic simulation. The main aim of this study is the analysis of heat generation from the system for heating and cooling purposes, with the use of sorption chillers. A computer simulation of the dynamic operation of the proposed solar heating and cooling system was developed within TRNSYS software. The experimental data were used to validate the model of the concentrator and solar collectors. Successively, a solar heating and cooling installation for a residential application, integrating the different configurations of solar energy collecting devices and thermally driven chillers, was proposed and dynamically simulated. Flat-plate, evacuated tube and photovoltaic-thermal collectors were considered along with absorption and adsorption chiller units. In the present study, different system configurations, localities and time bases were considered to investigate the energy and economic performance of the system. The model of the solar dish and collector arrangement overestimates the produced energy by less than 5% as compared to the experimental study. The results show that the space cooling demand is matched in 23.6 and 46.2% by solar energy in Warsaw, while in Lisbon from 38.2 to 46.1%. The simple payback period of the investigated system configuration was for Warsaw between 18.1 years for the combination of flat-plate collector and absorption chiller and 27.2 year for the photovoltaic-thermal collector with adsorption chiller.

In this study, single-effect and double-effect absorption refrigeration systems (SEARS and DEARS) are economically compared by considering life cycle cost (LCC) analysis in six different countries according to the type of the consumed fuel. Six cities in different regions including Phoenix (USA), Tarcoola (Australia), Ahwaz (Iran), Kota Bharu (Malaysia), Paya Lebar (Singapore) and Seville (Spain) are considered as the case studies. According to the results, in case of utilizing natural gas as the fuel of chillers, the double-effect system bears a lower life cycle cost in comparison with the single-effect system. Among the considered countries in this work, the lowest LCC is observed for Malaysia. Moreover, Singapore with $ 30,324 has the highest level of life cycle saving in cases chillers utilize natural gas. When the chillers are integrated with the Parabolic Trough Collectors (PTC) and auxiliary heater, except Paya Lebar, the SEARS outweighs DEARS considering the lower value of LCC; providing that the heater uses electricity or natural gas. The maximum life cycle saving levels belong to Paya Lebar and Seville with $2704 with $4674, respectively, in case of using natural gas and electricity as the fuel of the ancillary heater.

The performance of a multistage centrifugal compressor is highly influenced by the ambient conditions, especially during the summer seasons; their capacity shrinks and thus the power requirement for compression will increase. The prime cause of these constraints is the interstage cooling limitations. This study simulates various suction conditions of a multistage compressor on Aspen HYSYS® and suggests its debottlenecking by making the suction temperatures comparable to winter seasons. This is achieved by installing an additional exchanger at the downstream of each interstage cooler, cooling down the gas further by using absorption refrigeration chillers. These chillers are powered up by the waste heat recovered from the exhaust steam coming from the prime mover, steam turbine, of the same compressor. This modification will save a considerable amount of power (663 kW), net savings (Gross Savings – OPEX: 72 289 $/y), and reduce the carbon footprint (954 ton/y) of the overall process.

In this paper, a small-scale triple-hybrid air-conditioning system operated by biomass and solar energy resources is experimentally investigated. Comparisons with EnergyPlus simulations are also shown. Experiments reveal the necessity of system’s pull down because of inequality of heat transfer within the chiller. The biomass gasifier driving an electrical generator in combination with solar collector fulfils the total energy requirements that make the present system triple-hybrid in nature. An air-cooled lithium bromide–water operated absorption chiller of 4.06 kW rated capacity is fabricated and tested. The biomass-generated electricity enables to reduce the grid dependency of the system to fulfil net-zero-energy criterion. The system is tested under different generator temperature ranges (60 °C, 70 °C and 80 °C) and lithium bromide concentrations (54% and 58%) in water. With 54% concentration, this system operates up to 64.8% of nominal capacity with average coefficient of performance ranging between 0.14 and 0.19. However, with 58% concentration, up to 85.1% of its nominal capacity along with the coefficient of performance ranging between 0.19 and 0.25 can be acquired. The system caters the maximum load with the highest coefficient of performance of 0.34. Rise in the generator temperature improves the cooling capacity, coefficient of performance, shows quicker response of the system and drops the finally-attained room air temperature. Economic analysis reveals the payback time for the present system to lie in the range of 9–12 years. Finally, emission analysis reveals considerable possibility of greenhouse gas reduction in an affordable manner.

Chillers are an important component of the heating ventilation, and air conditioning industry which is one of the largest energy consuming sectors. Magnetic bearing systems have been adopted in the chiller industry to improve compressor efficiency. A life cycle assessment (LCA) of greenhouse gas emissions of magnetic bearing chillers, with a particular focus on the manufacturing stage, has not previously been conducted. This study evaluated global warming potentials of two water chiller systems, an oil lubricated bearing system, and a magnetic bearing system, over their life cycle stages including raw material extraction, manufacturing, transportation, use, and the end of life. The standard ISO 14044 LCA framework was employed to assess the two 500‐ton cooling capacity chillers from a US chiller manufacturing company. Uncertainty analysis was conducted on carbon emission factors from the research literature and sensitivity analysis was conducted on key variables including power mix emission factor, chiller efficiency, and transportation method. The results show that magnetic bearing systems perform better with respect to life cycle GHG emissions. For a general water chiller system life cycle, over 90% of the emissions result from electricity consumption during the use stage with the next largest emissions arising from material extraction and manufacturing. While the material use and manufacturing GHG emissions are similar in the two systems, due to its higher compressor efficiency the magnetic bearing system generates fewer GHG emissions in the use stage. Sensitivity analysis was conducted on electricity mix, non‐standard part load value (NPLV), and transportation method. When the factor values were varied with 5% steps to ±25%, the chiller efficiency and power mix emission factors behaved in similar ways in improving life cycle GHG emissions. NPLV, however, becomes more challenging to improve despite the long history of research on compressor efficiency. This study not only provides analytical data at the product level as to how much GHG emissions can be reduced by improving compressor efficiency and incorporating clean energy, but also provides life cycle GHG inventory data for different end of life and transportation strategies.

Este trabajo de investigación, tiene como objetivo mejorar el desempeño de una instalación solar de acondicionamiento de aire por absorción, por medio del diseño de un sistema de control simple, para fácil implementación. Esta instalación fue diseñada por E. Quintana (2012) en TRNSYS, un programa de simulación de sistemas. Con la visión de una futura implementación, un análisis de desempeño del Chiller de absorción se llevó a cabo en base a los resultados de la simulación del trabajo precedente. Se encontró que su desempeño no alcanza los rangos de operación segura dentro del tiempo de operación diaria, cada vez que el sistema se inicia. Basado en esto, el trabajo propuesto abarca el diseño de un sistema de control que permita mejorar el desempeño del Chiller de absorción, desde el punto de vista de seguridad de éste último y la reducción del consumo eléctrico de la instalación. La operación segura del Chiller se alcanza cuando éste y todo el sistema, operan dentro de los rangos nominales indicados por el fabricante. Los resultados indicaron que los parámetros a optimizar son las temperaturas del agua que entra al generador y al acumulador térmico. Empleando las estrategias de control diferencial On-Off y Feedback, los resultados de las simulaciones muestran que el primer objetivo fue alcanzado. Por el contrario, el segundo, no se logra alcanzar ya que la energía proveniente de la fuente solar no logra suplir las necesidades del Chiller dentro del tiempo de operación diaria.

Chillers play essential roles in the heating, ventilation and air conditioning (HVAC) systems to ensure the required thermal comfort. To reduce the operational risk such as faulty operation or ener...

One of the main disadvantages of conventional fixed-bed adsorption chillers is the low coefficient of performance due to the high voidage of the sorbent beds. The common method, which can help to h...

This paper addresses the present status of milk procurement practices in India, advancements in milk chilling technology, cleaning operations of milk chiller units and discusses the issues related to Bulk Milk Cooler (BMC) effluent treatment. Analysis of various physico-chemical parameters revealed that BMC effluent has wide variation in characteristics. BMC effluent discharged after every cleaning process are mainly characterized by the presence of high oil and grease (OG BOD3: 500-7700 mg/L), suspended solids (425-2450 mg/L) and dissolved solids (1075-4610 mg/L). Suitability of employing an anaerobic treatment system consisting of settling cum digestion chamber, baffle reactor and up flow media filtration was studied for its efficacy in treatment of BMC effluent at various loadings. The studies indicated that the stand-alone anaerobic-media treatment with OLR up to ~ 2.0 kg COD/m3.d and ~36-40 hours HRT was able to achieve substantial removal efficiencies of 82.77, 81.33, 96.92, and 94.2% for parameters COD, BOD, O&G, TSS respectively. Even though the system worked satisfactorily at higher loadings, it is necessary to adopt a holistic approach with an addition of tertiary treatment considering the complexity and wide variation in effluent characteristics in order to ensure its reuse for various non-potable purposes and ensure environmental compliance.

A prototype ejector chiller with nominal cooling power of 40 kW, designed according to the “CRMC” criterion, has been tested by our research group since 2011. The prototype has undergone several refinements and finally has been upgraded to R1233zd(E), which is non-flammable, has low-GWP and favourable thermodynamic properties, i.e. “dry-expansion” and moderate pressure at generator. In terms of saturation pressure curve, the new fluid is similar to R245fa, which was previously used in the prototype. Hence, R1233zd(E) has been basically used as a “drop-in” replacement. The ejector chiller was tested at different evaporation temperatures (2.5 to 10°C), typical of air conditioning applications. Saturation temperatures at generator from 95 to 105°C have been selected as representative of waste-heat recovery. The experimental findings prove that the CRMC ejector has a satisfactory performance with the new working fluid.

A cogeneration solar system for a building located in Sabzevar (Iran) is investigated in this study. In this system, a combination of a solar evacuated tube collector field and an auxiliary natural gas burner drive a single effect absorption chiller. Solar energy is also used to produce consuming hot water. Hourly cooling demands of the building were calculated during April to September. In order to perform a more obvious assessment, important parameters such as COP and efficiencies were obtained based on the total cooling load, the total amount of absorbed solar energy and consumed natural gas, and the total produced hot water during April to September. Energetic, exergetic, and economic analyses were performed in order to find the most efficient generator temperature. Considering the results, the minimum consumption of natural gas happened at a generator temperature of 104 ° C while the highest chiller exergy efficiency is observed at the generator temperature of 97 ° C. Also by assuming the required gas fuel to supply the consuming hot water -which is produced by solar energy-as a saving parameter, the economic optimum generator temperature to drive the absorption chiller and to supply the consuming hot water is obtained at the generator temperature of 96 ° C.

Investigating the pool boiling process in the absorption chiller generator by studying the valid parameters may enhance the chiller?s COP. In the present study, the transient 2-D numerical modelling of LiBr/H2O solution pool boiling in the generator of the absorption chiller was carried out using the two-phase Eulerian-Eulerian approach, extended Rensselaer Polytechnic Institute boiling model and renormalization group k-? turbulence model. The numerical model was applied on three types of the bare, notched fin, and low fin tubes to investigate the effect of using fin on the boiling heat transfer rate in the generator of the absorption chiller and comparing it with the bare tube. Moreover, the numerical results were compared with the data obtained from the previous experimental studies to validate numerical modelling. A good agreement was achieved between numerical and experimental results. The results showed the evaporation mechanisms in the microlayer, evaporation in the three-phase (liquid-vapor-solid) contact line, and transient conduction the superheat layer for constant thermal heat flux and the three surfaces of the copper tube within a specific period from the boiling point of LiBr/H2O solution. The results also showed that the use of a notched fin-tube and low fin tube increases the non-homogeneous nucleation rate, causes the solution boil earlier than the bare tube, and reduces the required thermal energy in the generator of an absorption chiller.

A critical issue concerning the gas turbine cycle of combined cycle power station is the reduction in net power output considerably with increasing ambient air temperature. The present simulation study aims to improve the performance of gas turbine cycle of combined cycle power station through use the fresh air handling units of mechanical chiller. To obtains the influence of use the mechanical chiller as pre-cooling units on a performance of gas turbine cycle, the thermodynamic analysis are used to simulate the performance of gas turbine cycle for three different operating loads (66.67, 83.33, and 100% full load). Based on results of the simulation analysis, the mechanical chiller which is inserted as a pre-cooling unit can; (i) increase the average monthly net power output by values varying between 7.33-18.17 MW compared to the original case without pre-cooling units; (ii) the rate of improvement in the average monthly net power output varies between 4.6-11% compared to the case without pre-cooling units; (iii) reduce the specific fuel consumption (SFC) by a rate varying between 5.21-10.81 kgfuel /MWh compared to the original case without pre-cooling units; and (iv) the saving in SFC reached to 4.4% compared to the original case without pre-cooling units.

This paper numerically investigates the performance of a high capacity, industrial ejector chiller working with the non-flammable, low GWP refrigerant R1233zd(E). The test procedures adopted to acquire the experimental data are explained in part 1 of this work. Different turbulence models were examined in order to accurately predict the ejector off-design transition and critical pressure. A peculiar difference has been noticed between the numerical results obtained when initializing the CFD simulation from the solution of a case with lower or higher condenser pressure. This difference may partly explain the difficulties in the accurate predictions of the critical conditions reported by this and other works in the literature. A detailed discussion is presented on the nature and possible cause of this phenomenon, which is identified as typical of non-linear fluid dynamics.

This work aims to provide a state-of-the-art review of the performance of combined cycle power plant (CCPP) based on several proposed inlet air cooling systems. Investigators strive to meet the significant need to promote and develop inlet air cooling technologies to recover heat from the wasted energy in the exhaust gasses of the CCPP and diminish the environmental impacts. Various types of cooling systems mainly offer a boost for electric power generation during the peak load hours. The output power of the CCPP directly depends on the mass flow rate of air that flows through the air compressor. Therefore, during extremely hot weather conditions, subsequently, the air density drops, and this leads to a drastic decrease in the power output. This paper reviews available studies investigated the impacts of inlet air cooling systems on the performance of the CCPP. The fogging cooling system contributed by up to 17% in improving the total performance of the CCPP; however, with the use of the evaporative cooling, the performance was enhanced by only 4%. The energy consumption of mechanical chiller compared to that of evaporative cooling is high due to the effectiveness of the evaporative cooler which depends on the humidity of inlet airflow. Further, the mechanical cooling system can provide the CCPP with a cooling effect for around 7-hour on-peak periods. This method increases the gain of the CCPP performance by 13.6%. Ultimately, the CCPP equipped with an absorption chiller demonstrates the best solution to increase the performance by up to 23%.

In this study, approaches developed by previous studies which to improve the characteristic equation method applied to absorption chiller were analyzed and an approach is proposed aiming to obtain a further contribution. A computational code was designed containing the chiller thermodynamic modelling and the characteristic equations obtained by each approach. The modelling results and the characteristic equations results were numerically compared and the COP and heat removed ( Q ˙ E ) deviations between them were calculated. The sequence of approaches aimed to reduce these deviations. The first approach computed the characteristic parameters and used them as constants values. The second approach used a linear adjustment between the minimum characteristic temperature difference (ΔΔtminE) and the characteristic temperature difference. The third approach used the previous approach adjustment, and the following were inserted in the characteristic equations: linear adjustments between ΔΔtminE; SE and the lift temperature (∆tlift), and between ΔΔtminE; SE and the thrust temperature (∆tthrust). The ∆tthrust adjustment obtained the lowest deviations. Using ΔΔtminE obtained directly from the input data, a better linear adjustment was achieved between ΔΔtminE and ∆tthrust. The use of this adjustment was treated as a proposed approach and achieved even smaller deviations. Then, a case study in a commercial chiller was performed with this approach. Most COP and Q ˙ E deviations values obtained in this case study were lower than 5%. Deviations between the manufacturer's datasheet values and the characteristic equations results were lower than 10%. Therefore, it can be understood that this approach can contribute to the characteristic equation method.

A standalone, compact, thermally driven ammonia-water absorption chiller designed to deliver a cooling capacity of 10.5 kW at ambient temperatures greater than 40 °C is presented. Heat and mass exchangers with novel microscale features and geometries are employed to minimize the physical size of the system. A diabatic distillation column based desorber and a shell-and-tube absorber with microscale features are used. Thermodynamic cycle modeling and heat and mass exchanger design methodologies are discussed. The performance of the packaged unit chiller is demonstrated experimentally over a wide range of operating conditions. The system delivered 10.6 kW of cooling at a COP of 0.63 at design conditions in a compact 0.7 m x 0.9 m x 1.0 m envelope. This work validates the scalability of microchannel heat exchanger technology from a proof-of-concept laboratory scale device to a residential-scale absorption heat pump.

Adsorbent-coated microchannels are used for the design of adsorption heat pumps, based on component-level fluid flow, heat and mass transfer modeling of a representative proof-of-concept unit with a cooling capacity of 300 W at 5 °C. Optimum channel geometry is determined using parametric studies. The use of adsorbent-coated microchannels results in operation with the heating time less than 10% of the total cycle time, opening the possibility for near continuous operation of the heat pump. Cyclic operation of the subject heat pump concept is simulated for the operating conditions used for silica gel-water chillers in the literature, and the results are used to document its benefits over those of existing designs. For a source temperature of 90 °C, cooling temperature of 35 °C, condenser inlet temperature of 42 °C, and evaporator outlet temperature of 5 °C, a Coefficient of Performance (COP) of 0.22 is attainable with a specific cooing capacity (SCC) of 177 W kg−1 without recovering any heat from the heating stage. COP > 0.55 and SCC ~1134 W kg−1 can be achieved for less severe operating conditions typically used in the literature.

In tropical and subtropical regions, air-conditioning commonly consumes the most energy in buildings. The chillers used in existing air-conditioning systems are largely based on thermodynamic vapour compression cycle because the cycle is highly effective, efficient and practical. Moreover, the system installation and operation are convenient when grid electricity is available. Popular vapour compression chiller types include air-cooled, water-cooled, seawater-cooled and oil-free chillers. In addition, thermal-driven absorption and adsorption chillers have become available in the market. Viable sources of thermal energy input include fuel combustion, renewable solar energy, waste heat, and so on. This paper provides an overview of different types of chillers and system configurations in terms of mechanisms, characteristics, energy efficiency, environmental performance and costs. The technical information and comparisons should help engineers select the chiller type in air-conditioning system design for achieving high sustainability.

Intensive use of heating, ventilation and air conditioning systems in buildings entails monitoring their efficiency. Moreover, cooling systems are key facilities in large buildings and can account up to 44% of the energy consumption. Therefore, monitoring efficiency in chillers is crucial and, for that reason, a sensor to measure the cooling production is required. However, manufacturers rarely install it in the chiller due to its cost. In this paper, we propose a methodology to build a soft sensor that provides an estimation of cooling production and enables monitoring the chiller efficiency. The proposed soft sensor uses independent variables (internal states of the chiller and electric power) and can take advantage of current or past observations of those independent variables. Six methods (from linear approaches to deep learning ones) are proposed to develop the model for the soft sensor, capturing relevant features on the structure of data (involving time, thermodynamic and electric variables and the number of refrigeration circuits). Our approach has been tested on two different chillers (large water-cooled and smaller air-cooled chillers) installed at the Hospital of Leon. The methods to implement the soft sensor are assessed according to three metrics (MAE, MAPE and $$R^2$$ ). In addition to the comparison of methods, the results also include the estimation of cooling production (and the comparison of the true and estimated values) and monitoring the COP indicator for a period of several days and for both chillers.

In this work, a new hybrid system for combined power and cooling applications is developed and investigated. The novelty of this research originates from two major achievements. First, the use of detailed analytical model for double-effect AC with fuel cell. Second, using two heat recovery systems (TEG and AC) to utilize the waste heat from a fuel cell. The system consists of a phosphoric acid fuel cell (PAFC), ThermoElectric generator (TEG), and an absorption chiller (AC). The internal heat generation in PAFC is utilized using TEG to achieve additional electricity production, while the exhaust heat by PAFC is utilized to run an AC to produce cooling power. The results show that the maximum useful power (electricity and cooling) obtained from this hybrid system is 11% greater than the maximum electrical power generated by the standalone PAFC. The maximum efficiency of this hybrid system is 7% greater than the maximum standalone PAFC efficiency, but the improvement can reach 10% when optimizing the system operating conditions. The sensitivity analysis study demonstrates that decreasing the operating temperature, increasing the fuel pressure, and decreasing the ambient temperature could enhance the overall hybrid system performance. Additionally, we found that a better performance is achieved when the heat utilized by TEG is minimized and majority of the useful heat is used in the AC.

The present study investigate the feasibility of absorption chiller utilization as part of trigeneration system that possibly applied in sub-tropical country building. Trigeneration is refer to the heat utilisation from electric generator (combined heat and power, CHP) to generate absorption chiller in order to produce chilled water for air conditioning system (combined cooling, heat and power, CCHP). Compare to the vapour compression system, absorption chiller that is mainly generated by heat waste, promised benefit economically and environmentally. Overall efficiency of CCHP can reach 71 % and possibly reducing emission until 146709.07 kg CO2. Economic analysis using the Payback period methodology has shown that the CCHP would produce a return on investment of 2.6 years. Improvements absorption chiller and support from government are expected to lead to increased return on investment and improved viability of the system.

Solar cooling technologies have been proven to have great potential for energy saving during cooling season. Meanwhile, glass has become one of the primary structural materials used in building construction since the middle of the 20th century. Although common glass adds to the aesthetic appeal of a building, it has serious drawbacks, such as creating heat traps, preventing natural ventilation and causing glare. Highly glazed facades would cause unwanted heat transmission from the ambient, which must be extracted to outside using an air-conditioning system. Internal heat resulting from facade configurations can be responsible for up to 45% of a building’s cooling requirements. A facade integrated solar cooling system can simultaneously improve building’s energy efficiency, utilise solar energy and still maintain a high level of architectural and aesthetic quality. This investigation presents a consistent approach for optimising and comparing facade integrated solar cooling systems in terms of technical and financial performance. Four systems (a vapour compression cycle (VCC) chiller driven by semi-transparent photovoltaics (STPV) arrays, a single-stage absorption chiller, an adsorption chiller and a vapour compression chiller coupled with organic Rankine cycle (ORC) driven by evacuated tube solar collectors) were assessed and compared with a conventional electric vapour compression chiller. The systems investigated were modelled in TRNSYS and the models were applied to predict performance parameters in various climate zones (seven cities) in Australia. The solar fraction (SF) and unit cooling cost (UCC) were the two parameters applied to quantify the technical and financial aspects of each solar cooling system in seven cities in Australia. It was found that among the systems investigated, the VCC chiller with STPV system has the highest SF (100% except in Darwin) and lowest UCC ($0.21 kWhr−1) for all seven cities in Australia. In general, due to the grid as a virtual storage, ORC-VCC system has higher SF (40% and 50%) and lower UCC (5% and 10%) compared with adsorption and absorption chiller respectively in subtropical and temperate climate zones.

To explore the performance of the ground source thermal energy management system under the cold and heat sources, based on the cold and heat auxiliary technology, a ground source thermal energy composite management system is constructed and simulated. The constructed ground source heat pump-refrigeration unit-hybrid heating management system of urban heating networks, as well as the simple system, are analyzed and investigated in terms of power consumption and underground temperature control. The research results show that the constructed ground source heat pump-refrigeration unit-hybrid heating management system of the urban heating network has lower power and energy consumption than a simple system during the same period, which meets the economic requirements and guarantees the system with relatively low energy consumption. For underground temperature control, the constructed system is more stable than a simple system without excessive temperature fluctuations. The operation control strategy of the constructed system is mainly for chiller units, heat pump units, cooling towers, source side, and side circulation water pump modules. In summary, the constructed ground source heat pump-refrigeration unit-hybrid heating management system of an urban heating network based on the ground source heat pump meets the requirements for energy consumption and temperature control and can operate the control strategy normally. The results are significant for subsequent researches on the ground source thermal energy management system based on cold and heat auxiliary technology.

A solar powered air-conditioning system designed for heating and cooling was put into operation and studies regarding the same triple effect refrigeration through solar thermal energy was carried out. Water, lithium bromide and other chemicals were used in the vapor absorption machine. Chiller having a capacity of 100kw i.e. 30TR was operated on the temperature of 210 0C obtained from solar field depending upon the solar radiations. This is the main part of the whole system because the heat produced by the solar field is used here for converting it into the chilling effect. The generator design of the machine allowed the use of hot water in the temperature range of 140-210 0C. The measured volumetric flow rate of hot water delivered by generator pump was ranging from 2 to 5.6m3/h.

The intermittent nature of solar energy is a dominant factor in exploring well-designed thermal energy storages for consistent operation of solar thermal-powered vapor absorption systems. Thermal energy storage acts as a buffer and moderator between solar thermal collectors and generators of absorption chillers and significantly improves the system performance. Vapor absorption chillers are available in half, single, double, and triple-effect modes of operation and operate at temperatures ranging from 75 to 220 °C to produce a cooling effect with COPs ranging from 0.3 to 1.8. Thus, the selection of appropriate solar collectors and thermal energy storages are two significant decisions affecting the consistency of output of a vapor absorption refrigeration system. The present review of state of the art is focused on the appropriate selection, from among different types of solar collectors available to meet the demand of capacity and degree of thermal energy required in operating absorption chillers at optimum performance. Characteristics of various thermal energy storage systems and their integration with solar thermal collectors and absorption chillers are also investigated to meet the demand for heat during non-sunshine hours or periods of low solar intensity. In the latter section, economic feasibility is explored so that a sustainable solar cooling system can be proposed which can work consistently with the best performance throughout its entire life.

A novel energy index to assess plants capable of producing electricity from a renewable source is introduced in this paper. This index allows to evaluate the bidirectional energy flows on the external power grid, due the electricity exported to the grid from a renewable-based system and the electricity imported from the grid, in comparison to the electricity demand of a building. In this paper, attention is focused on a solar photovoltaic (PV) system satisfying the energy demands of an office building. Electricity from the solar PV system is partly used to operate a ground source heat pump to meet space heating and cooling demands, and partly used for other electrical loads. An energy, economic and environmental impact analysis of the proposed system is also reported. A sensitivity analysis varying the photovoltaic system capacity (2.5–10.0 kW) and the battery storage size (3.2–9.6 kWh) is also carried out. A saving in terms of primary energy and a carbon dioxide emission reduction can be obtained by a renewable-based system compared to a conventional one consisting of a natural gas fuelled boiler for space heating, an electric chiller for space cooling and the national power grid for electricity demand.

The world today is in desperate need of clean energy, and among clean energy sources, geothermal energy possesses the highest potential. The maximum benefit can be obtained from clean energy sources if they are used together. This paper proposes the employment of a solar integrated geothermal heat pump. Furthermore, the paper provides a study on the comparison of six different types of solar integrated geothermal heat pumps based on various factors. (1) The heat produced by photovoltaic system combined with a boiler and a vapor compressor chiller. (2) The heating and cooling effect when photovoltaic system is integrated with a backup boiler. (3) Integrating the photovoltaic system with a reversible heat pump. (4) Use of solar energy in accordance with a backup boiler. (5) Integrating the previously combined solar energy and backup boiler to vapor compressor chiller. (6) Use of solar energy in combination with a reversible heat pump to produce heating and cooling effect. Each of these cases is compared to a process similar to itself that might have been previously used. The comparison between the processes points out the merits and demerits for both systems. The main reason for using this is to make use of fossil fuels reduce as it is harmful to the environment due to emission of gases like methane, carbon dioxide, ammonia and many harmful gases. While coal and oil produce a massive 1.08 tons of CO2 emission, use of geothermal energy could bring it down to about 0.05 tons which would be 21 times less then fossil fuels. To overcome this problem and for the benefit of environment, solar and geothermal both are integrated and provide better output.

Plug loads, or devices plugged into wall outlets, comprise a growing proportion of commercial building electricity consumption. This study presents the results of a hybrid approach for plug load management, which includes a combination of occupant engagement and centralized controls. Electricity consumption was monitored for 249 plug load devices in the XFINITY Center at the University of Maryland. After a baseline monitoring period, 1) on-off schedules were set for 78 devices in the concession stands, and 2) 31 office occupants in the facility took part in an energy competition and were given access to a mobile energy app (Keewi, Inc.) to control their 115 devices. Centralized controls resulted in a reduction of 58% in consumption in the concessions during the days when the concessions were not in use. Occupant engagement led to a reduction of 32% in plug load electricity consumption in the offices. Savings were largest in high-consumption categories such as merchandisers and food preparation chillers in the concessions, and IT equipment, refrigerators, desktop computers, and space heaters in the offices. The study indicates the benefits of hybrid approaches to plug load management given unique facility characteristics.

Radiant cooling systems (wall and ceiling) are low exergy systems which can help in solving efficiently the comfort needs of occupants. However, a complex energy and exergy analysis should be done in the design phase of such cooling systems in order to choose the most appropriate solution. This paper attempts to present a mathematical model and methodology of such a complex analysis and illustrates through a case study the energy and exergy comparison of cooling systems with mechanical compression and absorption cooling systems. Simple relations were developed in order to evaluate rapidly the energy and exergy efficiency of these types of cooling systems taking into account the avoidance of surface condensation. It was proven that, besides the coefficient of performances of installed chillers, the temperatures in the generator and absorber, respectively the supply and return temperatures are the main influencing factors of the exergy efficiencies of such types cooling systems. Based on the developed mathematical method a numerical analysis was done assuming different operational parameters of the cooling system used in practice.

Recognizing the rise of global life standards, the associated energy consumption, and the widespread use of air-conditioning systems, there is a clear necessity to evaluate the environmental loads associated with energy supply systems. This study applied the Life Cycle Assessment methodology to quantify the greenhouse gas emissions associated with a solar absorption cooling system to be installed in a university building. The current, conventional air-conditioning system is also evaluated, and the emissions are compared with the solar absorption system. The solar absorption system was designed and is constituted of absorption chillers, solar collectors and storage tanks. The conventional system employs different types of mechanical chillers (wall-mounted, floor-mounted, cassette). The total emissions associated with the air-conditioning systems are constituted by a fixed share, related to equipment, and a variable share, related to electricity consumption. The overall emissions associated with the solar absorption and conventional air-conditioning systems are 144,452 and 346,569 kg CO2-eq/year, respectively. The results presented herein demonstrate the potential of the solar absorption system to mitigate climate changes.

Vapour compression machines such as heat pumps and chillers are vital for achieving climate goals. Efficiency of both depend mostly on system integration. In order to simulate coupled energy systems, fast and stable simulation models are required. Hence, we implement an open-source model for reversible vapour compression machines. The black-box based refrigeration cycle is replaceable, additional inertia and losses are optional. Furthermore, we model relevant safety controls of vapour compression machines. To show validity of the presented approach, we first calibrate two different black-box models onto measured heat pump data. The table-based model fits both measured temperature and power with minimal calibration effort. Second, we show influences of different model options onto coupled building performance simulations. Computation time increases up to 50 % when enabling all model options. Simultaneously, seasonal efficiency decreases by up to 23 % when modeling all safety controls.

Temperature is a key variable to evaluate the energy consumption and thermodynamic performance of traditional marine auxiliary machinery, chillers and piping systems. In particular, for the cryogenic storage tanks and fuel gas supply systems of LNG ships, explosion-proof and low-temperature-resistance properties bring new challenges to the onboard temperature measurement and monitoring. In order to promote the development of high-performance and safer monitoring systems for LNG ships, this paper adopted fiber Bragg grating (FBG) technology to ensure the measurement safety and accuracy of temperature sensors, and performs a series of experiments in a large temperature range on the chiller, pipeline, and cryogenic storage tank of an LNG ship and their long-term reliabilities. Firstly, the principle and composition of the designed FBG temperature sensors are introduced in detail, and the measurement accuracy and range of different metal-coated optical fibers were tested in a large temperature range and compared against the traditional thermistors. Then, the effects of different operating conditions of the LNG marine chiller system and cryogenic storage tank on the temperature measurements were investigated. In addition, the drift degrees of the optical fibers and industrial thermistors were analyzed to figure out their reliabilities for long-term temperature measurements. The results showed that for the long-period (16 months) monitoring of LNG ships in a large temperature range (105–315 K) under different shipping conditions, the optical temperature measurement based on FBG technology has sufficient accuracy and dynamic sensitivity with a higher safety than the traditional thermoelectric measurement. Besides, the ship vibration, ambient humidity, and great temperature changes have little impact on its measurement reliability and drifts. This research can provide references and technical supports to the performance testing systems of LNG ships and other relevant vessels with stricter safety standards. Published version This research was funded by the National Natural Science Foundation of China (52006022), the China Postdoctoral Science Foundation (2020M680928, 2020M670726), Natural Science Foundation of Liaoning Province (2020-BS-067), the Fundamental Research Funds for the Central Universities (3132021211, 3132019368) and 111 Project (B18009). Their support is gratefully acknowledged.

Sustainable future and green environment goals quest for the development of technologies to utilize renewable energy resources to power the people. This study focuses on the designing, modelling, and simulation of an absorption solar air-conditioning system. Key performance parameters are identified, optimized for maximum efficiency and simulated in transient energy simulation software TRNSYS ®. The designed model comprises five thermal loops: a solar loop consisting of an evacuated glass tube solar collector having R-410A as heat transfer fluid in it and a heat exchanger heat tank, second loop has an absorption chiller, and an auxiliary furnace with hot water stream, third is the cooling tower loop, the fourth loop is of chilled water from the chiller and the final thermal loop is for air delivery of cooling to each room. The system is simulated using Lahore, Pakistan's climate conditions and offered a good tendency for the proposed system to meet air-conditioning demand at the domestic level. The average collector outlet temperature value of 78 °C has been recorded throughout the week. Collector provides useful energy gain at an average rate of 71,065 kJ/h. Average storage tank temperature at the outlet of heat exchanger is 92°C. Average room temperature values of three rooms are 27°C, 30°C and 19°C respectively.

International audience; This study investigates the impact of design and operating conditions on the performance of a falling film grooved plate absorbers integrated in a Lithium Bromide water absorption refrigeration machine. The performance of the component is described using two parameters: the mass efficiency and the absorbed vapour mass flow rate per unit plate width. The study implements a heat and mass transfer model validated with specific experimental data. The absorber effectiveness proposed by previous studies was generalized so that all absorbers' operating conditions could be considered. A parametric study considering variation of solution Reynolds number is conducted. Based on these simulations, global and local transfers are discussed. Highlights  Calculation of the mass effectiveness of absorbers  Heat and mass transfer modeling of grooved plates falling film absorber  Description of the operating conditions using the ratio of the maximum transferable flows between fluids  Efficiency Chart describing the Impact of flow rates on the mass effectiveness of absorbers

The food processing industry exists at the nexus between food, energy, and water systems. Improving the sustainability of this industry is critical to reduction of carbon emissions and enhanced utilization of vital resources such as water. The overarching aim of the present research is to create a process-based modeling platform for food processing systems that would allow the most appropriate combination of water-sustainable, energy-efficient, and renewable energy (WERE) technologies to be determined for a system. This paper focuses on one specific process in a thermal processing line: the cooling step after sterilization and prior to packaging. A typical process might use groundwater in a once-through loop. To reduce water use, two sustainable alternatives are considered and compared: (a) solar thermal coupled with an absorption chiller and (b) evaporative cooling of chilled water using a sub-wet bulb evaporative chiller (SWEC). The former uses a parabolic trough solar field with thermal storage that is connected to a single-effect water/lithium bromide (LiBr) chiller. The field and thermal storage are modeled using NREL’s System Advisor Model software and coupled to in-house Python code for the chiller and process heat exchanger. For the latter option, a novel SWEC is used as a chiller. The energy and water use, and capital cost of the two alternative technologies are presented.

One of the main elements for increasing energy efficiency in large-scale buildings is identified in the correct management and control of the Heating Ventilation and Air Conditioning (HVAC) systems, particularly those with Heat Pumps (HPs). The present study aimed to evaluate the perspective of energy savings achievable with the implementation of an optimal control of the HVAC with HPs. The proposed measures involve the use of a variable air volume system, demand-controlled ventilation, an energy-aware control of the heat recovery equipment, and an improved control of the heat pump and chiller supply water temperature. The analysis has been applied to an academic building located in Pisa and is carried out by means of dynamic simulation. The achieved energy saving can approach values of more than 80% if compared with actual plants based on fossil fuel technologies. A major part of this energy saving is linked to the use of heat pumps as thermal generators as well as to the implementation of an energy efficient ventilation, emphasizing the importance of such straightforward measures in reducing the energy intensity of large-scale buildings.

In agricultural areas with hot and arid weather, the losses of agricultural products increase due to a failure to access the appropriate cold storage. In the agricultural area far from the network, the solution would be solar-powered absorption chillers. This paper aims at the design optimization and improvement of the combined solar-powered cooling system to meet the required yearly cooling load for remote areas; considering the effect of different types of ETCs and cold storage volume on the performance of a solar-assisted absorption chiller. Such a system has been implemented in Anand, India and it supplies the cold demand of a 5 TR cold storage. A comparison of the system with different collectors shows that when the system is integrated with HP-ETC, the system performance is much more effective. HP-ETCs present 16.6% and 6.2% higher efficiency compared with the efficiency of the FP-ETC and U type-ETCs. The optimization shows that a 4 TR chiller with HP-ETC, a cold storage of 3 m3, and an operational temperature of 82.5 °C would efficiently supply the required cooling demand. Such a system would be able to keep 180 and 85 tonnes of potato and apple per year with a payback ratio of 11 years.