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A hybrid solar lighting/ thermal system utilized a parabolic solar dish as a solar collector illustrated in this paper. A two-axis tracking system was developed and employed to improve the energy output of a concentrating solar system (CSP) that produces hot water and light. During the daytime, sunlight is transmitted by fiber optics to an indoor photovoltaic PV device to generate electricity, or it can be used directly as daylighting. The heat generated is used to heat water. The findings show that the proposed system is a low-cost, high-performance approach for solar energy use in building energy efficiency, and readily available tracking components and tools. The experimental work shows that the maximum efficiency of the hybrid solar lighting/ thermal system controlled with a dual-axis solar tracking system was 32.2%.

This is a scoping review of agglomeration techniques to obtain of solid bodies from particle waste-materials for their utilization. For this purpose, the granulation and briquetting of fine coal and fly ash were presented in detail. Many successful works on solid fuels production, with coal only, and also with the addition of biomass, were presented. During the solid fuel combustion in power boilers, significant amounts of ash are generated. The properties of fly ashes were taken into consideration, and different methods of their utilization were proposed to obtain a wide range of useful products. Con-sequently, the waste resources of coal and ash were fully utilized. In final remarks, it was concluded, that the agglomeration techniques play an important role in waste management, but particularly in the circular economy.

A concentrating solar power (CSP) unit was designed to work as a hybrid system to supply the required energy for heat water and high intensity light. The system consists of a parabolic solar dish that reflected light in a set of optical fiber light inside a receiver. In turn, this light was transmitted to an indoor photovoltaic (PV) panels to produce electrical energy or used directly as a source of light during the day. This study revealed the following points: (i) the increased number of fiber optics, the improved efficiency of solar panel and power generated; (ii) the efficiency of the hybrid solar system was 23.62%. (iii) when the separation distance between the fiber optics and the PV module was closed, the level of the power generated becomes higher; and finally; (v) this application is more suitable for a limited area in the roof of the building.

The main purpose of any vehicular climatic control in terms of heating and air conditioning (AC) systems is to achieve maximum thermal human comfort with energy efficient. Therefore, it is importan...

A new concept of solid-solid mass diffusion fin was introduced in this paper. The authors described the mass diffusion in fluid flows to analyze the transfer process in solids and its applications, especially in metallurgical research. Using the advantage of the similarity between heat transfer and mass diffusion transfer will make this issue more practical. The authors suggested a new approach to determine the maximum mass diffusion transfer between two solids by implementing of the extended surface on each solid, where the optimal mass diffusion between solids is required. Then, meshing the surfaces together in order to increase the transfer efficiency was carried out. A complete analysis of the extended surfaces design (diffusion fins), its efficiency and effectiveness were presented. Moreover, mathematical models of each consideration were constructed. The authors found that the total surface efficiency increased along with the number of mass diffusion fins attached to the base, but its effectiveness did not. The mass diffusion for an extended plate increased the total mass diffusion transfer between two materials.

This work presents performance study of a concentrating photovoltaic/thermal (CPV/T) collector and its efficiency to produce electric and thermal power under different operating conditions. The study covers a detailed description of flat photovoltaic/thermal (PV/T) and CPV/T systems using water as a cooling working fluid, numerical model analysis, and qualitative evaluation of thermal and electrical output. The aim of this study was to achieve higher efficiency of the photovoltaic (PV) system while reducing the cost of generating power. Concentrating photovoltaic (CPV) cells with low-cost reflectors were used to enhance the efficiency of the PV system and simultaneously reduce the cost of electricity generation. For this purpose, a linear Fresnel flat mirror (LFFM) integrated with a PV system was used for low-concentration PV cells (LCPV). To achieve the maximum benefit, water as a coolant fluid was used to study the ability of actively cooling PV cells, since the electrical power of the CPV system is significantly affected by the temperature of the PV cells. This system was characterized over the traditional PV systems via producing more electrical energy due to concentrating the solar radiation as well as cooling the PV modules and at the same time producing thermal energy that can be used in domestic applications. During the analysis of the results of the proposed system, it was found that the maximum electrical and thermal energy obtained were 170 W and 580 W, respectively, under solar concentration ratio 3 and the flow rate of the cooling water 1 kg/min. A good agreement between the theoretical and experimental results was confirmed.

Adsorption chiller technology has received much attention in the last few decades due to its advantages in utilizing low grade thermal energy and eco-friendly refrigerant. However, it has not been wide commercialized due to its low coefficient of performance (COP) and low specific cooling power (SCP) compared to conventional refrigeration technologies. This paper reviews different strategies to improve the COP and SCP of adsorption chillers. Heat recovery, mass recovery, multi-stage, multi-bed, improved adsorption structures and optimized operating conditions are discussed in this review. This study revealed that: (i) for operating conditions of low evaporative temperature, low generation temperature or high condensing temperature, a mass recovery technique is strongly recommended; (ii) in the case of intermittent cold production systems, use of constant temperature adsorption cooling cycle strategy is preferred; (iii) an appropriate cycle time and switching time are important to achieve the optimal system performance since the adsorption chiller performance is strongly dependent on the operating conditions; (iv) by employing a novel composite adsorbent material, along with improvements in heat exchanger design, advanced adsorption cycles can be a promising technology to improve adsorption chiller performance. This review highlights the need for further research to reduce chiller manufacture costs, increase power-to-mass ratio and improve understanding of dynamic long term chiller performance when driven by solar or waste thermal energy.

Hospitals and other healthcare facilities are complex environments that require a special consideration to HVAC design as in requirement a large amounts of ventilation, which leads to high amount of energy consumption. This manuscript presents a description of chilled water/ HVAC systems for health care facilities. A case study of a Farah hospital located in Amman/ Jordan was implemented to perform cooling load using radiant time series (RTS). This paper manipulates the effect of changing relative humidity with dry bulb temperature on the cooling load, power consumption and chiller selection using three types of building namely: commercial building, hospital building and green hospital building to choose the best indoor design conditions with minimum power consumption. To reduce the energy cost for chiller, a solar photovoltaic was proposed to overcome the portion of the air conditioning power requirement and reduce the demand on the electrical grid. A proposed solar photovoltaic technology unit was analyzed and modeled using a hybrid optimization model for renewable energies (HOMER) software. The results revealed that: (i) the applying green building criterion will lead to significant reduction in cooling load and power consumption up to 25%; (ii) A higher relative humidity and in design inside temperature, a lower cooling load and power consumption required, (iv) PV systems sizing depend on load data, solar radiation, battery data, inverter data and investment cost of the system, and finally (v) there is a potential to adopt solar PV as strategic and alternative option to reduce the cooling cost.

It presents a method to extract pure water from atmospheric air, which depends on intensifying the water vapor from the air. The plant was designed to perform the optimum levels to produce high quality water with minimal electricity consumption. The harvesting water was inspected and analyzed based on ISO/IEC 17025 method to check the purity of water. This study also investigates the potential of a solar powered using for atmospheric water generation (AWG) as a new option for fresh water production. A proposed solar AWG unit was assembled, analyzed and modeled using HOMER software. The results demonstrated that the water produced by the water extraction plant is pure, safe, economical, and acceptably tasting. It can be used as drinking water after treated by filter and disinfected by Ultra Violet Light (UV) technique. The feasibility analysis showed that there is a potential to adopt solar powered of AWG as strategic and alternative option for a small area; which is suffering from a shortage of drinking water.

This paper presents the possibility of using the numerical methods to analyze the work of hydraulic systems on the example of a cooling system of a power boiler auxiliary devices. The variety of conditions at which hydraulic system that operated in specific engineering subsystems requires an individualized approach to the model solutions that have been developed for these systems modernizing. A mathematical model of a series-parallel propagation for the cooling water was derived and iterative methods were used to solve the system of nonlinear equations. The results of numerical calculations made it possible to analyze different variants of a modernization of the studied system and to indicate its critical elements. An economic analysis of different options allows an investor to choose an optimal variant of a reconstruction of the installation.

Magnetic refrigeration is a fascinating superior choice technology as compared with traditional refrigeration that relies on a unique property of particular materials, known as the magnetocaloric effect (MCE). This paper provides a thorough understanding of different magnetic refrigeration technologies using a variety of models to evaluate the coefficient of performance (COP) and specific cooling capacity outputs. Accordingly, magnetic refrigeration models are divided into four categories: rotating, reciprocating, C-shaped magnetic refrigeration, and active magnetic regenerator. The working principles of these models were described, and their outputs were extracted and compared. Furthermore, the influence of the magnetocaloric effect, the magnetization area, and the thermodynamic processes and cycles on the efficiency of magnetic refrigeration was investigated and discussed to achieve a maximum cooling capacity. The classes of magnetocaloric magnetic materials were summarized from previous studies and their potential magnetic characteristics are emphasized. The essential characteristics of magnetic refrigeration systems are highlighted to determine the significant advantages, difficulties, drawbacks, and feasibility analyses of these systems. Moreover, a cost analysis was provided in order to judge the feasibility of these systems for commercial use.

This manuscript analyzes the sub-systems of evaporative cooler (EC) combined with desiccant dehumidification and regeneration for automotive air conditioning purpose. The thermodynamic and psychometric analysis was conducted to design all evaporative cooling system components in terms of desiccant selection, regeneration process, compact heat exchanger and evaporative cooler. Moreover, the effect of the desiccant, heat exchanger and evaporative performances on the mass flow rate and water sprayed required for evaporative cooling system was investigated. The results show that the theoretical evaporative cooling design will achieve two main objectives: lower fuel consumption and less environmental pollutants. However, it has the two drawbacks in terms of increased weight and reduces the coefficient of performance (COP). The main remark is that evaporating cooling system is more efficient than the conventional air conditioning when the gasoline price is more than 0.34 $/liter.

The energy demand for cooling and air conditioning systems is increasing worldwide, especially in regions with high solar radiation intensity. One of the reasons for this is the increase of comfort demands worldwide. The most cooling and air conditioning systems are the conventional electrically driven one type such as compression refrigeration machines and air conditioning systems. Through the huge electricity consumption for cooling and air conditioning, the environmental problems get bigger and bigger, because of carbon dioxide (CO2) and other pollutant emissions. One of the possibilities to reduce the primary energy consumption is through the use of solar energy for driving the thermal driven absorption or adsorption refrigeration systems, or desiccant cooling. Another possibility is using solar energy to produce electrical energy and this can be used to drive the conventional refrigeration systems. Many research and developmental efforts in the last years have been done to enforce the spreading of solar-driven cooling systems. This paper will illustrate the state of the art about the energy consumption for cooling and air conditioning systems, available solar-driven cooling systems and the potential of the utilization of such systems in comparison to the conventional ones. Moreover, this paper highlights some different methods of optimization, which used to maximize the performance and minimize the cost.

Radiative properties of transparent insulations made of a layer of parallel, small-diameter, thin-walled, visible light transparent pipes placed perpendicularly to the surface of a flat solar absorber are investigated theoretically. A formula for the radiation heat losses through the insulation is derived based on two main assumptions: the system is in steady-state and the fourth power of the temperature along each pipe is linear. Arguments in favor of the assumptions are given. The formula, combined with standard formulas for the conductive heat flux, enables prediction that a 10 cm thick transparent insulation under insolation of 1000 W/m2, at ambient temperature 20 °C, could theoretically raise the absorber temperature to 429 °C and produce 410 W mechanical power under the ideal Carnot cycle. In order to reach that high energy conversion efficiency, the insulation pipes should have diameter less than 0.5 mm and walls about 5 μm thick, which may be technologically challenging.

The adsorption chiller technology makes possible to construct the chillers that can be powered by a low temperature heat source, which improves the efficiency of the energy and minimises the level of environmental pollutions. It has been found that adsorption chillers are valuable when the heat source is affordable as cogeneration, solar, geothermal, or waste heat sources, especially in situations when the heat is partially dissipated in the environment. On the other hand, adsorption chillers are non-competitive if the heat is delivered from dedicated combustion of fossil fuels, hence the relatively low COP of adsorption chillers against compressor chillers. For this reason, it was proposed and tested three-beds with dual evaporators of 100 kW adsorption chiller driven with low temperature heat from cogeneration. In order to achieve the highest performance, the switching time was optimized. It was found that the best adsorption performance is at switching time of about 900 sec to get the highest COP around 0.645 and total cooling capacity around 90.5 kW.

This manuscript presents the design and construction of the energy efficient, time saving, cost effective of passive solar powered clothes dryer. This manuscript begins with a derivation of mathematical model represents of solar dryer followed with an analysis of the elements necessary for successfully designing the various components of a solar dryer. The solar drying performance achieved an average drying rate of 0.35 kg/h and drying time of 3 h in a typical day, even under local low ambient humidity of around 35% and at moderate outdoor wind speed. Also, the computational fluid dynamic CFD of transient thermal behavior based on Navier-Stokes equations was used to demonstrate the prevailing temperature rises in the solar natural-ventilation system associated with the internal heat flux due to solar radiation and moisture removal. The efficiency of solar dryer was improved using Nano coating technology. The result showed good agreement between the computational solid simulation and the experimental measurements obtained from this system.

This manuscript presents the comparison of using the cold water and brine as a storage source of refrigeration for milk cooing process based on the accumulator volume and power consumed at variable of cooling load. Also presents the effective of using cold storage in term of accumulator to reduce the refrigeration capacity and energy saving.This manuscript begins with a derivation of mathematical model represents of cooling system followed with a computer program to integrate and simulate the appropriate equations to evaluate accumulator volume and power required for water and brine system. The results showed that the accumulator volume using cold water was 58 m 3 and 59.21 m 3 for cold brine at the same conditions with 206 kW of maximumcooling load, peak duration of 3.5 hours, water temperature difference 2 C, and operating period of refrigerating unit up to 17 hours a day. Also, it was found the power required to operate the compressor of water system around 45%less than the power needed to operate the compressor of cold brine system.

The use of a variable refrigerant flow (VRF) is being specified as an alternative solution to centralize HVAC systems in domestic building. This manuscript presents a comprehensive description of the configuration for the indoor and outdoor units of a multi-split VRF system. A case study of a hotel in Amman, Jordan was implemented. The suitable indoor and outdoor units were selected according to heating and cooling load. A sensitivity analysis of the effect of some parameters on heating and cooling loads were analyzed. Finally, the thermal human comfort indices of PMV and PPD were investigated. This study showed that even the main shortcoming of using VRF system due to its high initial cost, but this system is encouraged especially in small places due to its energy efficiency appeal at partial loads, satisfying optimum thermal human comfort, and a good substitute where scarcity of water and achieving more thermal human comfort. Keywords: VRF system, Air conditioning, Cooling, Heating, Human comfort, PMV, PPD, HAP program

SUMMARY Presented study discusses the development of a finite differencing (FD) thermal model for a power-split hybrid configuration employing a nickel-metal hydride battery pack. A resistance–capacitance electro-thermal model is used to couple the experimental boundary conditions (current, voltage, state of charge, and temperature) with the modeled battery resistance to capture its electro-chemical behavior and the cell exothermic reactions. Battery current, voltage, and temperature (discrete and full field) for a vehicle with a power-split hybrid configuration were collected under different standard (Federal Highway Driving Schedule and Federal Urban Dynamometer Driving Schedule (FUDS)) and artificially generated driving cycles. This manuscript analyzes the battery current and voltage in relation to vehicle speed and shows how the proposed FD model predicts the spatial and temporal temperature profiles of the power train in good agreement with the vehicle data as reported by the on-board diagnostics module. Copyright © 2011 John Wiley & Sons, Ltd.

This manuscript discusses the effect of manipulating the Relative Humidity RH of in-cabin environment on the thermal comfort and human occupants’ thermal sensation. The study uses thermodynamic and psychometric analyses, to incorporate the effect of changing RH along with the dry bulb temperature on human comfort. Specifically, the study computes the effect of changing the relative humidity on the amount of heat rejected from the passenger compartment and the effect of relative humidity on occupants comfort zone. A practical system implementation is also discussed in terms of an evaporative cooler design. The results show that changing the RH along with dry bulb temperature inside vehicular cabins can improve the air conditioning efficiency by reducing the heat removed while improving the Human comfort sensations as measured by the Predicted Mean Value PMV and the Predicted Percentage Dissatisfied PPD indices.

This manuscript discusses the development of a 3D thermal model for a power-split hybrid powertrain, including its battery modules and power electronics. The 3D model utilizes a finite differencing (FD) heat transfer algorithm, complemented with experimental boundary conditions. The experimental setup is configured to acquire the battery current, voltage, and its inner and surface temperatures in discrete and in full-field scans. The power-split hybrid configuration is tested using a standard and artificial driving cycles. A battery resistance model is then used to couple the experimental boundary conditions with the finite differencing code, which employed a cell-based internal heat generation model to describe the pack chemical reaction mechanism. This study presents a complete analysis based on battery current and voltage in relation to vehicle speed. The proposed model also predicts the powertrain spatial and temporal temperature profiles in agreement with the vehicle actual conditions as indicated by the On-Board Diagnosis (OBD) module.

This manuscript provides a comprehensive review of the different models developed to predict vehicular cabins thermal comfort, in addition to the different experimental techniques used. The review classifies the in-cabin modeling into; human physiological and psychological perspectives in addition to the compartment zone and the human thermal manikin modeling. While the experimental approaches are mainly; the subjective observers, the thermal manikins, and the Infrared Thermography. Additionally the manuscript discusses and analyses each of the thermal indices that are typically used in assessing the in-cabin conditions such as the Predicted Mean Value PMV index and the Predicted Percentage Dissatisfied PPD. The text also highlights the main attributes of vehicular thermal comfort, in terms of its fast transient behavior, the in-homogeneity in the thermal fields associated with the high localized air velocity, solar loads and flux, in addition to the inherent variations related to the trip durations.

This paper investigates the potential of utilizing the exhaust waste heat using an integrated mechanical device with internal combustion engine for the automobiles to increase the fuel economy, the useful power, and the environment safety. One of the ways of utilizing waste heat is to use a Stirling engine. A Stirling engine requires only an external heat source as wasted heat for its operation. Because the exhaust gas temperature may reach 200 to 700°C, Stirling engine will work effectively. The indication work, real shaft power and specific fuel consumption for Stirling engine, and the exhaust power losses for IC engine are calculated. The study shows the availability and possibility of recovery of the waste heat from internal combustion engine using Stirling engine.

This manuscript presents a fault detection method for a SI engine at variable speeds using acoustic signal technique. Two faults were addressed: misfire and the malfunction of manifold absolute pressure (MAP) sensor. The main objective is to detect these two faults by measuring the sound pressure level (SPL) in decibels (dBA) at different engine speeds and one octave frequency bands in the audible human range, and then compare the results to the normal operating SPL engine. The experiments were conducted using a four cylinder, four stroke spark ignition Mitsubishi Lancer sedan engine (1.6 L) model 2006. The experimental results showed that: 1) the SPL due to misfire malfunction increases as the engine speed decreases; 2) at low frequencies the difference between the two values of SPL is very small compared at high frequencies; 3) the curve shape for SPL follows the shape of the power produced from the engine.