Performance Testing and Analysis of Silica Gel-Water Adsorption Refrigerator

In recent years, adsorption refrigeration technology has attracted wide attention from experts and scholars at home and abroad due to its environmental friendliness and energy saving advantages. In order to study the effectiveness of adsorption refrigeration technology to recover low-grade energy, a silica gel-water adsorption refrigeration system was proposed, which can effectively utilize low-grade energy such as industrial waste heat. The structure and composition of the system are introduced. The operation performance of the unit is tested under different working conditions by orthogonal experimental method, and the experimental results are analyzed. The effects of hot water temperature and flow, chilled water temperature and flow on the refrigeration capacity and COP value of the system are obtained. The experimental results show that under the low-temperature heat source of 55-75°C, the cooling capacity of the system can reach 5.3-12 and the COP value can reach 0.36-0.56. Under the same hot water temperature difference, the cooling capacity and COP value of the system increase rapidly under the condition of changing the hot water temperature at low temperature, indicating that increasing the heat source temperature at low temperature has a greater impact on the system performance. Through the analysis of primary and secondary effects, it is concluded that the inlet temperature of hot water is the main factor affecting the refrigeration capacity and COP value of the system.

Design Optimization and Simulation of an Ice Plant Working by Solar Adsorption Technology

This research presents a design optimization of a solar adsorption ice plant using activated carbon and methanol as working pairs in the climate of Makkah to produce a ton of ice per day. The plant consists of six adsorption refrigeration units. Each unit has 72 separate cylindrical adsorbent beds connected with its own condenser, valve, and evaporator. The unit is heated by seven evacuated-tube collectors connected in parallel. Then the total number of collectors are 42 collectors. The beds are filled by estimated amount of 540 kg of activated carbon with 178 kg of methanol. Selection and dimensioning of each component were carried out based on previous recommended values. A mathematical model and simulation were developed to validate the system performance along the year. The results showed that plant could produce up to ton of ice daily along the year. The coefficient of performance can reach 0.9 with condenser and evaporator temperatures of 35°C and -5°C respectively. The performance of the system is greatly affected by ambient temperature than solar radiation. Therefore, the best performance and largest amount of ice was found in the winter season.

Research on Solar Adsorption Refrigeration System

In order to achieve solar adsorption refrigeration, this paper studies the surface water source solar absorption refrigeration system combined with surface water source cooling and solar absorbent refrigeration techniques: the solar radiation intensity is adjusted by changing the distance between iodine tungsten lamps and solar cold tubes. The results show that the entire cycle has a range of solar radiation intensity of 400 to 1000 W/m2, and the indoor ambient temperature ranges from 19 to 25∘C, and the humidity is maintained around 40%. The highest temperature in the solar cold tube adsorption bed is 12∘C; during the adsorption process, the temperature drops to about 20∘C; the solar cold tube is 160 kJ in one cycle of the solar cold tube, and the cooling coefficient is about 0.15. Conclusion: solar cold tubes can effectively utilize solar refrigeration, it is a refrigeration method for environmentally friendly, no greenhouse effects and ozone destruction, which has potential application value and has energy saving and environmental protection.