The Simulation And Experimental Analysis Of The Small Steam Absorption Chiller

With the improvement of the living conditions and the higher request for thermal comfort environment, air conditioners have been used in building widely. The electricity energy consumed by air conditioners takes a great proportion in the total national energy consumption. Overusing electricity energy has thrown great pressure on the city electricity network. The environmental problems caused by electricity-powered air conditioner have also attracted more and more attentions. As an new energy system, Building Cooling, Heating & Power (BCHP) can lessen the electricity imbalance and shortage caused by overusing electricity to great extent. The Micro-BCHP project cooperated by some famous universities and companies not only contains the characters of traditional BCHP, but also owns some new points. The author participated in this project and took charge in establishing the mathematical model of the small chiller and testing it.This thesis reviews the research products of the absorption chiller, introduces the working stream of the Micro-BCHP system and also the working principle of every component. The small steam absorption chiller is used as the cooling source of the Micro-BCHP system. The rating cooling capacity of this chiller is 16kW.This chiller uses LiBr as the absorbent and the water as refrigerant. The steam produced by the heat exchange of the solar energy and the heat energy of the fuel cell exhaust is shipped to the steam absorption chiller as heat source. This thesis establishes the steady mathematical model of this steam chiller and compiles the calculating program in MATLAB which can optimize the chiller design and simulate system operation. The program uses the mass flow rate of the water vapor in high pressure generator as assumption variable firstly and the heat balance of the components as convergence condition, the program will calculate iteratively till the convergence condition is met. The testing program and the testing results are also presented. Testing data includes the temperature of the inlet and outlet chiller water, the temperature of high pressure generator, condensed water and heat source, the pressure of the inlet steam, etc. The results of simulation and testing show that the mathematical model is matched with the testing data. This thesis concludes the following conclusions by experimental analysis: The stability of steam pressure is one of the important facts that affects the normal operation; increasing the steam pressure or reducing the condensed water outlet temperature and recovering the heat of condensed water can effectively enhancechiller COP .