Experimental study on closed-cycle solar adsorption cooling system

A closed-cycle solar-powered adsorption cooling system is designed.The system is mainly composed of the evacuated tubular solar collectors with an area of 150 m^2,two adsorption chillers with a rated cooling capacity of 15 kW,a cooling tower,fan coils and circulating pumps.The experiments were carried out to study the operating characteristics and the performance of the system.It is found that the operation of the system presents wave characteristics because of low water capacity.The water temperatures of the inlet and the outlet of the solar collector array cyclically swing since the water entering the solar collector array comes directly from the adsorption chillers.Besides,the inlet water temperature of the adsorption chillers varies distinctly.However,the cooling effect of the system is satisfactory.Compared with an open-cycle system,the closed-cycle system has the advantage of a high electric COP（coefficient of performance）because of the reduced use of circulating pumps.

Application of Renewable Energy Options—The Role of Solar Adsorption Cooling Technology

High energy requirement of vapor compression cooling systems in addition to harmful refrigerants further necessitates the increasing need for more reliable, flexible, environmentally friendly, and cost-efficient cooling systems options. Adsorption cooling technology could be a better option in terms of huge energy saving potential, Carbon emission reduction, flexibility, and waste heat utilization. There are, however, some setbacks that hindered adsorption cooling technology from real mass production and commercialization. This work seeks to study, evaluate and compare the energy requirement and coefficient of performance of solar-powered adsorption cooling system (as an application of renewable energy) in relation to vapor compression system. Adsorbate/adsorbent equilibrium test (using a test rig) was used to predict the performance of thermal driven adsorption cooling system using methanol/activated carbon (as adsorbate/adsorbent pair) in relation to similar data obtained from laboratory vapor compression refrigeration test rig (same mass of refrigerant). For the adsorption cooling system and vapor compression system, the energy requirements were found to be 1913.57 kJ and 8932.02 kJ while the coefficient of performance (COP)s were found to be 0.39 and 1.2 respectively. Presumably, the adsorption cooling system has an energy requirement that could be powered by direct solar thermal heating using a flat plate collector, however, the COP is relatively lower indicating lower cooling capacity, and hence takes a longer period of time to overcome the same cooling load as vapor compression system. It is recommended among other things that research should focus on developing better adsorbate/adsorbent pairs for an increased adsorption/desorption time.

Impact of Numerous Beds Operating Conditions for Enhancing the Performance of a Solar Heat-Supported Adsorption Chiller

Thermal adsorption cooling systems have gained significant attention due to their potential for energy savings and eco-environmental impact. An analytic investigation of the heat transfer inside an adsorption chiller with various bed silica gel-water pairs is presented. A comprehensive model has been designed to accurately predict the correlation between the overall performance of the proposed chiller system and the functional and structural condition of the building. This model takes into account various factors such as temperature, humidity, and air quality to provide a detailed analysis of the system’s efficiency. At least 20 collectors consisting of a 34.4 m area (each) with a full-cycle time of 480 seconds are essential to improper run conditions. It is necessary to adjust the optimum cycle time for optimal performance. During the investigation, the base condition shows that the cooling capacity is 14 kw, 0.6 COPcycle, and 0.35 COPsolar at noon. Also, conduct a thorough investigation into the chiller’s performance under varying cooling water supply temperatures and various chilled water flow rates.

Multiperspective Analysis of Microscale Trigeneration Systems and Their Role in the Crowd Energy Concept

The energy system of the future will transform from the current centralised fossil based to a decentralised, clean, highly efficient, and intelligent network. This transformation will require innovative technologies and ideas like trigeneration and the crowd energy concept to pave the way ahead. Even though trigeneration systems are extremely energy efficient and can play a vital role in the energy system, turning around their deployment is hindered by various barriers. These barriers are theoretically analysed in a multiperspective approach and the role decentralised trigeneration systems can play in the crowd energy concept is highlighted. It is derived from an initial literature research that a multiperspective （technological, energy-economic, and user） analysis is necessary for realising the potential of trigeneration systems in a decentralised grid. And to experimentally quantify these issues we are setting up a microseale trigeneration lab at our institute and the motivation for this lab is also briefly introduced.

Solar air conditioning researches and demonstrations in China

This paper mainly shows the demonstration of solar air conditioning systems in China, which includes LiBr-H2O absorption cooling, silica gel-water adsorption chiller, desiccant cooling and hybrid integrated energy systems for buildings. The match of solar collector types and chiller types have been discussed and suggested.