Steady Simulation Of Vapor-Cmopression Refrigeration System And Analysis

The existing research model of refrigeration system is"theoretical prediction, experiment and experience"."Experiment and experience"plays the most important role. In experiment, there are many factors to cause results deviation. It is also high energy consumption. Because CFCs and HCFCs refrigerants cause destruction of atmospheric ozone layer and greenhouse, they will be substituted. At present, there is a lack of character of new refrigerant. Existing experience is not used. The traditional model of"Experiment and experience"is replaced by computer simulation. Using the simulation results analyzes system parameters of change on system performance.Taking single-stage vapor-compression refrigeration system as the study object, according to conservation theorems, based on reasonable simplification of every component, mathematical models of compressor, condenser, evaporator and expansion have been done. Connected the models accordance with process of refrigerating cycle system, state mathematical of system is established,Visual Basic simulation program is compiled and solving the model. Using the results, study on the impact of structural parameters of condenser and evaporator, the performance of different conditions, and the performance match used substitution R290. The results are as follows:(1) Analysis of the impact of tube diameter, fin spacing, tube pitch, head-on wind speed and air flow of condenser and evaporator to performance of system, obtain the performance curve. It analyzes refrigerant charge quantity of system and obtains the influence law.(2) It analyzes he feasibility of R290 as alternative to R22 from thermophysical properties and theory refrigeration cycle. Studied the refrigerant charge quantity of R290 and analyzed system parameters in the condition. The results show that after using R290, it needs 43.47% quantity of R22 to achieve the same refrigeration effect.(3) Calculated EER and exergy loss in R22 circle and R290 circle at the same refrigeration and proposed to method to increasing the efficiency. The result shows that exergy loss is largest in condenser and evaporator. Heat exchange of R290 is better than R22 in condenser.