| High temperature heat pump technology is widely used in the paper,chemical industry and other industrial production.It has prominent advantages in reducing environmental pollution and providing high-grade heat energy.The main research directions of high temperature heat pump are the development of high temperature heat pump technology and the pursuit of superior cycle performance.The paper demonstrates the superiority of in predicting the properties of refrigerants.The modified methods were respectively proposed for COSMO-RS in predicting the saturated vapor pressure of pure working fluid and the vapor liquid equilibrium properties of the mixture working fluids.By predicting the saturated vapor pressure of R245 fa and the vapor-liquid equilibrium properties of binary system R600+ R245 fa,it was verified that the proposed modified methods can improve the prediction accuracy of COSMO-RS in high temperature and pressure region.A new binary mixture high temperature heat pump working fluid NBY-1 was developed.Meanwhile,vapor liquid equilibrium properties of working fluid NBY-1 at the condensation temperature of 85-135°C were predicted by the modified COSMORS.NBY-1 was used as the working fluid on the high temperature heat pump experimental device.By changing the opening of electronic expansion valve,adjusting the flow rate of circulating water on the evaporator side and the condenser side,and changing the filling quantity of working fluid,the COP of heat pump system reached 2.75 when the inlet temperature of evaporator was 80°C and the outlet water temperature of condenser was 130°C.The experiment of changing the temperature of the low temperature heat source showed that NBY-1 had a high ability to raise the temperature.When the inlet temperature of the evaporator was 60°C,the maximum temperature rise of 70°C can be achieved.On the other hand,the experiments on heating conditions were carried out,and the experimental results were compared with those of working fluids on the same heating conditions in the references.The results showed that the COP of NBY-1 heat pump was better.For example,when the inlet temperature of evaporator was 70°C and the outlet temperature of condenser was 90°C,the COP of the system can reach 5.84.Therefore,extending NBY-1 to the field of heating can alleviate the shortage of gas caused by coal-to-gas conversion and reduce the emission to the environment.It has a very wide application potential in the field of heating.Finally,when the temperature of evaporator inlet and condenser outlet were separately 80°C and 115°C,the high temperature and pressure flow field of refrigerant in the scroll compressor was simulated by Fluent.The pressure field,velocity field and temperature field of the refrigerant were analyzed to discuss the fluid-structure interaction characteristics with the mechanical equipment. |
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