| High temperature heat pump is an energy-efficient,environmental-friendly and cost-effective technology that can upgrade the quality of thermal energy.It can recover a large amount of low temperature waste in the industrial process to provide high temperature thermal energy,which satisfy the heat demand of other fields.With the promotion of the upper limit of heating temperature,the main objective of the high temperature heat pump is the optimization of cycle performance and the coupling between working fluid and mechanical equipment.This paper established four thermodynamic cycle calculation models for Carnot cycle,theoretical cycle,theorized actual cycle and experimental cycle,which represent the evolution process of cycle from ideal to actual.According to the difference between different cycles,17 influence parameters of cycle performance were systematically summarized.Furthermore,with working fluid NBY-1 at the heating temperature of 130℃,this paper used the parameterization method to analyze the difference between the theoretical and experimental coefficient of performance,quantitatively analyze the irreversible loss during the cycle.On the one hand,based on the experimental results of R22,BY-3,BY-5 and NBY-1 working fluids under different working conditions,using 17 influencing parameters as independent variables,the multiple regression model of COP and heating capacity were established.At the same time,the most significant influence parameter of the COP was found based on two multiple regression models.On the other hand,the physical model of scroll compressor was established in this paper based on the geometric parameters of the scroll compressor.The basic profiles of the scroll wrap are circular involute,and the top profiles of scroll wrap were modified with two arc shaped curves.In addition,a three-dimensional numerical simulation model of the scroll compressor was completed,with dividing of the mesh of fluid domain in the compression chamber and the discharge port and the setting of boundary conditions and other solution settings.Finally,this paper used the scroll compressor numerical model to simulate the cycle characteristic of working fluid NBY-1 at 115℃,120℃,125℃and 130℃,respectively,to verify the correctness and reliability of the model.Also,the effect of compressor speed on the fluid-solid interaction with working fluid NBY-1 and compressor was studied.In addition,the prediction on cycle performance of the new working fluid NBY-1 was exert at the heating temperature of 135℃.In order to find the structural parameters law of the optimal operation of the scroll compressor,this research also studied the influence of the height of scroll wrap and correction angle on the cycle parameters of the working fluid. |
