Refrigeration System Design And Experimental Study On Absorption Of Low Grade Heat Ammonia Water

Use waste heat resources of approximate200℃flue gas from industrial enterprises to achieve cooling, to solve the enterprise life district cooling, so as to realize the energy saving and emission reduction. Determined the refrigerant of each state and the related physical parameters refer to the ammonia water enthalpy concentration diagram, and designed the structure of thermodynamic calculation and an important component of the system cycle refrigeration unit. Designed and built a low grade waste heat ammonia absorption refrigeration experimental platform with a capacity of12KW, and studied the system in different operating conditions.The main research work includes the following points:First of all, designed and built a platform based on low grade waste heat of ammonia absorption refrigeration test bench. Determined the system running processes and refrigeration cycle at each state point parameter and main components of the heat load and system components for the design, selection, while supporting the installation of electrical control system and experimental measurement system. Realized the real-time monitoring of pressure, temperature and water cycle system parameters, and provided a platform for experimental study on absorption performance of the system to carry out heat type ammonia.Secondly, studied the different flue gas input temperatures, cooling water inlet temperature, and the valve opening (evaporation temperature) effect on the system performance. The experimental results showed that:when temperature was240℃, the system obtained the most optimized energy efficiency; system performance reduced when the temperature of the cooling water inlet increased; the COP could reach0.537when the temperature of cooling water inlet was18℃in the experimental process; experimental process cooling water inlet temperature of35℃, the COP down to0.403; refrigeration effect decreased with the decrease of evaporation temperature system, evaporation temperature control was achieved by adjusting the throttle opening, to meet user demand for cooling capacity cold, cooling the two forms of the chilled water and ice.Finally, a numerical simulation method, this paper discussed solution heat exchanger was studied. The results showed that:the simulation results than the theoretical calculation was closer to the actual situation, the effect of solution inlet velocity of solution heat exchanger greatly. When dilute solution inlet velocity increased from0.253m/s to0.506m/s, the concentration of solution flow rate increased from0.259m/s to0.518m/s, the heat exchanger heat flow value increased from10.20kW to18.77kW, the heat transfer coefficient from599.97W/(m2·℃) was increased to728.46W/(m2·℃)。Through theoretical analysis combined with practice, we provided the way of a high efficient use of low grade waste heat. We used ice carrier transport to do remote implementation of waste heat resource, realized the full use of energy. Furthermore, we provided a certain basis for the optimization of refrigeration system using low grade waster heat resources.