The Research On The Variable Water Temperature Control System Of The Small Absorption Chiller And Simulation

Developing small absorption air conditioner (SAAC) can release high pressure of the electricity network in cities, protect environment and ensure our country's sustainable development, when the demands in household air conditioner increases and the electrical air conditioner, which consume great deal of electricity, take almost 100% of the market share of small air-conditioners. However, the low COP value of SAAC restricts its development. By using variable water temperature control system, we can improve effectively both the performance and energy efficiency of SAAC.In this paper, the structure of SAAC was firstly studied and analyzed. Then the performance of a 16kW SAAC is tested and studied. Test data was obtained at working conditions. Some data of the change of chilled water outlet temperature under the influence of heating steam and load disturbances were also obtained.Dynamic mathematical model of the fixed temperature and steam control system of a steam driven SAAC was built by the means of experimentation and computer simulation, which based on PID control method. The parameters of the optimum control state were obtained through parameter determination of the controller.The variable water temperature control system that based on PID controller was studied to deal with dynamic space load and refrigerating capacity of SAAC. And its dynamic mathematical model was developed and the simulation programmer is written. The simulation result shown that this control system has good control quality.The simulation model of the whole SAAC was proposed by adopting the static state and concentrated parameter model. The model was validated by test data, which illustrated that the model is quite fine. At the same time, It was proved that with the variable water temperature control system, the SAAC can be avoided to run in bad state, such as crystallization.Finally, the energy consumption of SAAC with variable water temperature control system was studied. The result shown that SAAC with the variable water temperature control system has better energy efficiency than that with fixed water temperature.