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The Earth to air heat exchanger (EAHE) is an effective passive cooling and heating system for buildings. This paper studied numerically the potential for reduction in energy consumption for cooling and heating loads for a residence equipped with an EAHE system in the climate of Nasiriya city, which is located in southern Iraq and at 31.7°N and 45.8°E, latitude and longitude, respectively. Also, this paper presents a study about the thermal performance of three types of EAHE systems, system 1, consisting of one layer of EAHE and buried at an available area of house garden with 3‐m depth, system 2, at the same site of system 1, but with two layers of EAHE at two depths, 3 and 4 m, and finally, system 3, buried along the area of the house at a depth of 3 m. First, the built numerical model was validated against experimental results, and the results of the comparison showed good agreement. The electricity consumption for cooling and heating of the house is calculated with and without the EAHE system. The results showed that with using EAHE, there is a considerable saving in energy and saving in the cost of electricity consumption, which reached 376 329 IQD ($301.11) over 1 year for system 2. [ABSTRACT FROM AUTHOR]

The cooling water system is an indispensable part in the removal of the indoor cooling load in heating, ventilation, and air‐conditioning (HVAC) systems. However, the complexity and strong coupling characteristics of the controlled objects lead to unsatisfied control effects in most practical engineering applications. In this paper, the cooling water system is studied as a whole from the perspective of online application. Firstly, the mathematical models of the cooling water system are introduced and simplified based on the experimental data from the actual system. The simplified models have easy obtained inputs and programmable structure, which renders higher feasibility and practicality for the model‐based control method applied in the real system. On this base, an easily implemented control method for cooling water system is proposed to improve the global efficiency. By comparing with the conventional constant temperature difference control strategy and constant speed control strategy in the simulation platform, the proposed water flow optimization control strategy is superior in both global COP and energy saving at the same operating conditions, and 0.37% and 3.45% of energy consumption can be saved, respectively. The simulation results imply that the proposed simplified method is a referable control method for designing or retrofitting the real cooling water system. [ABSTRACT FROM AUTHOR]

Airflow windows (AFWs) help to stabilize the thermal environment in the perimeter zone and also allows for switching between solar‐shielding and solar heat acquisition operations. This is based on the method of channelizing the air discharged from its cavity layer, either by using a total heat enthalpy exchanger and choosing to exchange heat or otherwise. It has a certain thickness owing to the blinds that are installed in its cavity layer. The purpose of this research is to develop a window system that uses electrochromic (EC) glass, instead of blinds, as a solar‐shielding device. This study also provides the specifications of the window system of reduced thickness. The performance of the window system is assessed by CFD analysis. The solar heat gain coefficient (SHGC) of the proposed window system is found to range from 0.083 to 0.268 and its solar radiation properties can be controlled in a flexible manner. These characteristics contribute to an improvement in the building environmental performance in the form of climate‐adaptive building shells (CABS) in places with four distinct seasons such as Japan that require solar‐shielding to reduce the cooling load in summer and solar heat gain to reduce the heating load in winter. [ABSTRACT FROM AUTHOR]

Here, a new energy‐saving optimization method, known as the Improved Particle Swarm Optimization (IPSO) algorithm, is proposed to solve the practical engineering problem of high energy consumption during the operation of central air‐conditioning water systems. The mathematical model of total energy consumption optimization and the calculation principle of the IPSO are established. It is shown via experiments that the proposed algorithm requires a short optimization time and can achieve the optimal operation conditions of water systems under various cooling loads, where these conditions include the optimal control strategy of equipment, and water temperature at the inlet and outlet of chillers. Furthermore, it ensures the lowest energy consumption of water system operation. The measured results show that the comprehensive energy saving rate of water system operation can reach more than 18% compared with that before the system transformation. [ABSTRACT FROM AUTHOR]

In hot‐arid climatic regions like Qatar, it is important to facilitate pedestrians' journeys. One way to do so is by providing them with shelters, that is, from a station to their destination building. It is necessary for such shelters to provide on‐site space cooling and freshwater in an off‐grid condition. In this respect, the proposed off‐grid system in this study includes bifacial photovoltaic (BPV) and a solar thermal collector for energy generation with battery and thermal storage units. BPV with an efficiency of 16% can produce power up to about 6.1 kW on the rooftop, which also reduces the cooling load via effective shading. The ejector‐based cooling system is deployed for efficient space cooling in high ambient temperatures (more than 28°C), while for less than 28°C, both fan and water misting systems are operated for the comfort of pedestrians. Finally, an electrodialysis system is integrated to generate freshwater from seawater to be used for drinking and water misting purposes in the off‐grid sustainable shelter. The overall energy and exergy efficiencies of the system are calculated to be 13.2% and 5.29%, respectively. The effects of several parameters are also studied to observe the overall system efficiency and the energy generated and consumed by the system. [ABSTRACT FROM AUTHOR]

Modeling studies have been carried out to investigate coupling of an solid oxide fuel cell auxiliary power unit (SOFC APU) with a small scale NH3-H2O based vapour absorption refrigeration system (VARS) for a refrigerated truck/trailer application, by using hot cathode exhaust from the SOFC stack to drive the VARS. A bottom up design and modeling approach has been adopted where the end requirements, cooling load in this case, are identified first followed by upstream modeling of the SOFC and VARS unit. This approach enables design of system/components to meet the desired end requirements rather than compromise or fall short of the desired goal. Initial modeling results show that it is indeed possible to couple an SOFC with a VARS on a small scale (< 10 kW cooling load) for the refrigerated truck application. As this novel strategy utilizes both heat and power from the SOFC it promises a higher total efficiency up to 80% and also removes a significant part of the load from the main diesel engine, thereby leaving the engine to carry out the task of only propelling the vehicle. The excess electrical power from the SOFC could also be used to charge the vehicle batteries. [ABSTRACT FROM AUTHOR]

To overcome the problem of walking in the scorching heat and to encourage people to use more public transport (ie, trams and metros), the idea of sustainable climate refuge shelter is highly needed. In this study, the proposed shelter includes semi‐transparent photovoltaic cells located on the roof integrated with batteries to keep the system running at nighttime and in unfavorable irradiation conditions. An atmospheric water generator for freshwater production is employed for drinking and water misting in addition to a vapor compression cooling system with a fan. Freshwater is collected by extracting water from humid air through cooling with dehumidification. The system is analyzed thermodynamically through energy and exergy efficiencies. The overall energy and exergy efficiencies of the system are 19.45% and 9.58%, respectively. The electrical efficiency of the photovoltaic cells decreases from 16.87% to 15.24% with an increase in cell temperature from 309 K to 315 K. Hourly analysis of the proposed system for the whole year is performed to evaluate the energy profile. The proposed system generates electricity in winters that is sufficient to keep the system operational for 2 days (only for drinking water requirement), but in the summers, only 24 h due to extensive cooling load. The effects of several parameters such as irradiance, ambient temperature, relative humidity, transmittance, and occupancy rate are studied. [ABSTRACT FROM AUTHOR]

This paper describes some tests performed on concrete specimens heated up to high temperature and then cooled down in water. The tests were carried out on cylindrical specimens, 103 mm in diameter and 200 mm in height, made of ordinary concrete with siliceous aggregate. The specimens were heated up to 330, 430 and 550°C and then cooled down to room temperature in five various ways. A first group of specimens was cooled in air, while a second was immersed in water for 5, 10, 15 or 20 minutes, respectively; after the rest period in water the specimens were cooled in air. The next day, after the heating and cooling process, the residual concrete compressive strength was measured. Rapid cooling of heated-up concrete had the highest influence on the strength degradation when the maximum temperature peaked at 330°C while, in the case of thermal cycles peaking at 550°C, the strength degradation was less dependent on the method of cooling. It was concluded that rapid cooling of heated-up concrete can cause a significant strength degradation, especially in the range of low temperatures. [ABSTRACT FROM AUTHOR]

This research is proposed to fully investigate the performance of a single‐effect water/lithium bromide absorption chiller driven by geothermal energy. Since absorption cycles are considered as low‐grade energy cycles, this innovative idea of rejecting fluid from a single‐flash geothermal power plant with low‐grade energy would serve as efficient, economical, and promising technology. In order to examine the feasibility of this approach, a residential building which is located in Sharjah, UAE, considered to evaluate its cooling capacity of 39 kW which is calculated using MATLAB software. Based on the obtained cooling load, modeling of the required water/lithium bromide single‐effect absorption chiller machine is implemented and discussed. A detailed performance analysis of the proposed model under different conditions is performed using Engineering Equation Solver software (EES). Based on the obtained results, the major factors in the design of the proposed system are the size of the heat exchangers and the input heat source temperature. The results are presented graphically to find out the geofluid temperature and mass flow and solution heat exchanger effectiveness effects on the chiller thermal performance. Moreover, the effects of the size of all components of the absorption chiller on the cooling load to meet the space heating are presented. The thermal efficiency of the single‐flash geothermal power plant is about 13% when the power plant is at production well temperature 250℃, separator pressure 0.24 MPa, and condenser pressure 7.5 kPa. The results show that the coefficient of performance (COP) reaches about 0.87 at solution heat exchanger effectiveness of 0.9, when the geofluid temperature is 120℃. [ABSTRACT FROM AUTHOR]

A rate‐based model of an absorption column was developed and used to analyze several intercooling strategies utilizing "heat exchange packings." These packings are capable of removing heat from the column and transferring it to a cooling fluid within the packing. For absorption of CO2 into aqueous monoethanolamine under industrial conditions, intercooling via heat exchange packings placed along 10–20% of the column could reduce the column height by ∼15%. The height of these columns was close to the minimum theoretical value, calculated by numerically optimizing the temperature profile. Effective intercooling could also be achieved by using the cool, rich solvent as the cooling fluid. This reduces the cooling load and facilitates recovery of waste heat. Heat exchange packings could also be used to redistribute heat within the column, reducing the column height with no net cooling load. However, this approach requires larger heat transfer coefficients than have been experimentally observed. [ABSTRACT FROM AUTHOR]

Most houses in Japan have the floor‐length windows to take the natural light into the room. Reflected solar radiation and Re‐radiation from the ground (Reflection) enter through the window and increase the cooling load, therefore reducing reflection to the building is necessary. We focused that reflection is greatly affected by the ground surface, its heat flux may vary depending on the height from the ground. This study presented the thermal influence by the vertical distribution of reflection on the building in various climate areas and considered the solar shading method based on that distribution. The calculation results using Sol‐Air Temperature showed that the incident heat flux of reflection increased on the lower part of the building surface, and the vertical distribution of reflection existed in various areas. We propose to shield up to the lower half part of the building as a solar shading method considering the vertical distribution of reflection. This method could be able to shield most of reflection and incorporate natural light from the top half of the window to ensure room brightness and view, that is expected to be effective in improving indoor comfort and reducing the load of cooling and lighting. [ABSTRACT FROM AUTHOR]

This study presents an investigation of the potential use of thermal energy storage for shifting cooling and heating loads to off‐peak hours in order to balance the electricity production and demand periods. In Canada, the main energy source for cooling and heating applications is generally electricity. Therefore, cooling and heating devices have a great impact on the electricity peak load. In this study, it is considered that heating and cooling loads on the electricity peak load periods are shifted to off‐peak hours by thermal energy storage systems. At the end of this study, it is observed that the thermal energy storage has great potential for shifting electricity peak load depending on cooling and heating load to off‐peak periods. The electricity peak loads can be reduced by 25% and 45% by shifting heating and cooling loads to off‐peak hours and doing storage. Furthermore, the thermal energy storage systems can help reduce both cooling and heating costs in Canadian dwellings by 20% and 18%, respectively. [ABSTRACT FROM AUTHOR]

In our previous report (Nihei et al. [2015] J Architect Plann (Transactions of AIJ), 80, 2429–2437), we created a list of building elements and net quantities of the dwelling unit design to investigate the condominium design that takes the thermal environment into consideration. In this report, we added "Cooling Load," "Heat Loss Amount," "Solar Heat Gain Amount in Cool Period," and "Eaves Depth/Opening Height" to the study. First, we demonstrated the validity of the design criteria related to insulation. Next, we clarified the possibility of reducing the cooling load according to the dwelling unit design, excluding external conditions. [ABSTRACT FROM AUTHOR]

A pulse tube refrigerator (PTR) was developed to operate at different cooling capacities to meet the requirements of various applications. Changes in the thermal loads or the long operating time of the PTR will influence the cold conditions (cold‐end temperature and heat load), leading to a deviation of the cooling performance from the optimal design conditions. The basic principles of the mass flow characteristics of the PTR are constructed based on enthalpy phase modulation, which is helpful for comprehending the relationships between cold‐end parameters and other parameters. A REGEN model is introduced in which different mass flows at the cold‐end are considered to simulate the effects of the cold‐end parameters on the performance of the regenerator. The influences of the cold‐end temperature and heat load on the cooling performance are investigated by using a coupling model of a DeltaEC model and a REGEN model. In addition, some experiments are performed on a PTR working at different cold‐end temperatures and heat load. The experimental results are in good agreement with the simulation results. The cooling performance of the PTR is influenced by the average pressure and operating frequency of different cooling states. Relative Carnot efficiencies of 12.2% for 4 W@60 K with a specific power of 33 W/W and 16.1% for 15 W @120 K with a specific power of 9 W/W can be achieved by the PTR using different operating parameters. [ABSTRACT FROM AUTHOR]

In developed countries, the buildings are responsible for massive energy consumption. When the construction is based on the use of nonsustainable methods, the buildings were dependent on the active systems, for ensuring a maximal indoor comfort. This has increased energy consumption and related greenhouse gas emissions. In this study, a reduction technique of cooling load and power consumption in buildings is proposed. This technique involves the combination of three passive cooling techniques, thermal insulation, phase change materials (PCMs), and electrochromic double glazing. These techniques are applied through simulation software "DesignBuilder" to a building envelope model in various areas like walls, roofs, and glazing. For this purpose, a standard building model is compared with 16 other cases that incorporated the passive cooling techniques for determining the effectiveness of the proposed method. The results show that a combination of PCMs, thermal insulation, and double glazing can reduce the cooling load from 70.37 to 50.53 kW and the energy consumption from 1.51 to 0.90 kWh/m 2. [ABSTRACT FROM AUTHOR]

Divertor targets made out of a capillary porous system (CPS) filled with liquid lithium, have been proposed as an alternative to standard, solid state plates. In the current work we simulate the DEMO edge plasma in either a standard single-null or snowflake divertor configuration. Our tool is the 2D code TECXY. Lithium ablated from the target plate surface and released into the plasma is shown here to partially screen the incoming heat flux. Lithium's moderate SOL radiation levels suggest additional seeding to be beneficial. Very high heat fluxes to the divertor need to be avoided, as intensive lithium evaporation might unacceptably pollute the plasma. [ABSTRACT FROM AUTHOR]

In Indian commercial potato cold storage facilities, the air temperature does not remain constant during the loading period. Also, because of stepwise loading pattern, the product loaded on different days would undergo different time-temperature histories. Under this transient condition, the product takes longer to reach the steady state and loses more moisture of about 1.7% during 1 month of storage period. In addition, the sensible product-cooling load is different for the product loaded on different days. In the present study, therefore, the product temperature, moisture loss and sensible product-cooling load were predicted for the product loaded on different days under the condition of variable storage air temperature in the range of 3.5–10C and constant relative humidity of 90% using the computational fluid dynamics technique. It was found that the product loaded during the middle of loading period incurred more moisture loss than that loaded during early and latter stages of loading. However, the former case imposed more sensible product-cooling load. The trends of temporal variation of average product temperature, moisture loss and sensible product-cooling load depended on the day of loading of the product in the cold storage facility. [ABSTRACT FROM AUTHOR]

The building energy consumption and energy saving rate in office buildings with Dye‐doped liquid crystal (DLC) smart window under the change of region, window‐wall ratio and orientation were simulated by DeST‐C. The results indicated that the energy saving rate of DLC smart window increased with the rising proportion of cooling load in different regions: Harbin < Beijing < Shanghai < Guangzhou. When DLC smart window was used in Shanghai, the energy saving rate increased with the increase of window‐wall ratio. Moreover, DLC smart window in different orientations generally resulted in different energy saving rate: North < South< East