Increase the heating capacity, the compressor suction flow, the middle suction temperature, the
Condenser and the evaporator water side resistance have undergone major changes, that is, in accordance with the design conditions of a single component in the system, the heat pump system heating Parameter exceeds its design value. The above performance parameters and design values are inconsistent is due to the mismatch between the single component. From the perspective of product design and development, the heat exchange area of the heat exchanger has become a key parameter for changing this mismatch between components under the condition that the structural parameters of the compressor can not be changed (the type of the compressor is decided by a professional manufacturer) (The structure parameters of the throttling mechanism have less influence on the system performance). Therefore, this paper regards the heat exchanger area of the heat exchanger as the optimal design object. Area ratio optimization design simulation Ato take a specific value to optimize the area ratio. Keep Are as constant initial design values and examine the effects of different area ratios on COP for Ato = 70 m2, as shown. From a we can see that COP and Qc with the area ratio of the opposite trend in the area ratio of about 1, the system to obtain the maximum Qc, and the corresponding COP value is small; area ratio of about 1.5, from b and c, Within the optimized area ratio, both the flow rate and pressure drop of water in the two devices meet the design requirements (pew is beyond the scope of the constraint, but the magnitude is not significant). b and c water flow rate and resistance in the area ratio close to 1 when the sudden increase is due to changes in the type of heat exchanger caused, and then led to a sudden change in the length of the pipe. According to the above simulation results, the optimization area of the total area of the heat pump system studied in this paper is, the optimized range of the two device area ratio is. The analysis shows that the area of the regenerator varies with the compressor exhaust Temperature has a great impact, but also affect the size of the system COP, therefore, should also study the regenerator and the two area ratio issues. For two different area ratio of the regenerator area changes on the system performance simulation results. It can be seen from a that, when Are is constant, the smaller the area ratio is, the larger the Qc is. In the same area ratio, Are is larger and the Qc is smaller; in many working conditions, there are working conditions that meet the design requirements of heat supply 14. However, as can be seen from b, in condition 14, the exhaust gas temperature in condition 4 has exceeded the system exhaust gas temperature limit. From c, it can be seen that in condition 13, condition 3 has the highest COP. Are = 7.0m2, the area ratio of 1.4. According to the design conditions completed by a single component of the high temperature heat pump (such as compressor, two devices, regenerator, throttling mechanism, etc.) in the structural design of the system, high temperature heat pump system The main performance parameters of heat, compressor suction, intermediate suction temperature, condenser and evaporator water side resistance all have great changes compared with the design value, that is, there is a mismatch between the initial design results of single components . In the compressor model has been determined under the premise of optimizing the design heat exchanger heat transfer area is an effective way to solve this problem. The COP of high temperature heat pump increases with the increase of the total area of two devices, but the relative increase of COP to the total area is relatively small, that is, increasing the COP of the system by increasing the total area of the heat exchanger is of little significance, but increases the cost of the device . During the optimization of the total area of the two devices, the system design heat supply is a key constraint parameter. Based on the parameter, a reasonable range of the total area can be determined. Based on this, the rationality of other constraints is examined. CONCLUSION In practice, the regulation of climate compensator can affect the outlet water temperature of the boiler and thus change the operating status of the boiler, which can alleviate the contradiction between the boiler output and the terminal load to some extent. However, due to the change of bypass water flow under its control The range is small, and the calculated temperature does not really correspond to the water temperature at the end of the load, and many climate compensators can not really solve the boiler output and end load mismatch issues.
May 31, 2022
