| The energy-intensive industries in China,Europe and the United States produce trillions of joules industrial waste heat every year.Most of waste heat is directly discharged into the surrounding environment in the form of waste heat,resulting in huge energy waste and low energy utilization efficiency.Energy-saving and environmentally-friendly energy utilization technologies,especially technologies that can utilize industrial waste heat can help alleviate waste of waste heat resources,improve energy efficiency,and reduce energy consumption which are in line with national strategies.Compared with other refrigeration methods,silica gel-water adsorption refrigeration has the advantages of high energy saving,environmental protection and pollution-free operation,so it is usually used in solar refrigeration and waste heat recovery and other occasions.Further promoting the application of silica gel-water adsorption refrigeration systems,giving full play to its advantages of not requiring conventional refrigerants such as Freon which will cause ozone hole environment pollution,efficiently using energy especially waste pollution are the ultimate technology.Existing research is mainly focused on improving the performance of adsorption systems,including cooling capacity and COP(Coefficient Of Performance),from the aspects of refrigeration cycle and selection of working pairs.The discussion of application is less.In addition,the existing research on the practical application of silica gel-water adsorption refrigeration products is more based on solar heat-driven refrigeration,and there is less research on the recovery and utilization of industrial waste heat.In view of the above problems,this paper discusses the application of silica gel-water adsorption refrigerators in industrial waste heat recovery and utilization.This paper analyzes the current waste heat recovery and utilization.Based on the current industrial waste heat recovery methods and difficulties,the advantages of silica gel-water adsorption refrigeration technology for industrial waste heat recovery are analyzed from three aspects: the heat source temperature matching,performance coefficient comparison and heat source temperature fluctuation adaptability.The paper summarizes the current silica gel-water adsorption refrigeration technology and its research progress and makes a theoretical analysis of the application of silica gel-water adsorption refrigeration technology in industrial waste heat recovery including the analysis of thermal cycle diagrams,determining the temperature range of industrial low temperature waste heat below 90 ℃ and the construction of two low-temperature waste heat recovery systems of data center waste heat recovery and air compressor waste heat recovery.The silica gel-water adsorption water chiller and air chiller are designed.The water chiller is added with mass recovery cycle and the evaporator of the air chiller has a heat pipe structure.The working pair are silica gel with the size of 0.5-1.5mm and water.Efficient heat exchange design improves the performance of the system.The test system for two chillers are established for conducting experiments and analyzing the experimental results.Based on theoretical and experimental analysis,the application of silica gel-water adsorption refrigeration in industrial waste heat recovery is completely feasible.The experimental results show that the inlet temperature of hot water and cooling water,chilled water/cold air outlet temperature,cooling time and hot water flow will affect the system performance.Under the condition of changing only one parameter,increasing the hot water inlet temperature,lowering the cooling water inlet temperature,increasing the chilled water/cold wind outlet temperature,and increasing the hot water flow can improve the system’s operating performance and the utilization of industrial waste heat resources.In addition,the two chillers have their best return time and best cooling time.Keeping the chillers running at the best mass recovery time and the best cooling time can improve the system’s operating performance and improve the utilization of industrial waste heat resources.In summary,this paper starts from the research status of silica gel-water adsorption refrigeration technology and industrial waste heat,and verifies the feasibility of the silica gel-water adsorption refrigeration unit for industrial waste heat recovery.Two chillers for different practical occasions are designed and two test system are set up.The factors that affect the system operating performance are analyzed.This paper provides theoretical,design,and experimental guidance for the further promotion of the subsequent utilization of silica gel-water adsorption refrigeration chillers for industrial waste heat recovery and improvement of energy utilization efficiency. |
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