Air source transcritical CO2 heat pump and multi-melting-point phase change heat storage coupling heating system

Abstract

The invention discloses an air source transcritical CO2 heat pump and a multi-melting-point phase change heat storage coupling heating system. The multi-melting-point phase change heat storage coupling heating system comprises a CO2 air source heat pump machine set, a first variable frequency pump, a high-melting-point phase change heat storage device, a user, a second variable frequency pump, a low-melting-point phase change heat storage device and a plurality of electromagnetic valves, wherein the secondary heat exchange side of a CO2 transcritical circular heat pump heating system is combined with the multi-melting-point phase change heat storage device; the low-melting-point phase change heat storage device is used for absorbing waste heat of return water, so that the temperature of the return water is reduced, and then the temperature of a working medium before a throttling valve and the throttling loss are reduced, thereby causing the temperature glide in the CO2 exothermic process to be in temperature matching with hot water very well and giving full play to the unique advantages of the CO2 transcritical circular heat pump heating system. In addition, when the peak value of electric power or the heat supply efficiency of the heat pump is relatively low, the system is switched into a heat release mode, and the heat of the phase change device is used for heat supply. The multi-melting-point phase change heat storage coupling heating system provided by the invention has the beneficial effects that the multi-melting-point phase change heat storage coupling heating system can operate and be controlled at different period of time during wave crest and wave trough of electric power, and then the comprehensive utilization performance of the heat pump machine set is improved.

Description

[0001] Technical field: [0002] The invention belongs to the field of HVAC, and specifically relates to an air source transcritical CO 2 Heat pump and multi-melting phase change heat storage coupling heating system. [0003] Background technique: [0004] In recent years, my country’s smog pollution has erupted frequently and its degree has become more serious. It not only affects the health of residents and the safety of traffic, but also has a major negative impact on social production and life. The pollution emissions caused by coal-fired heating is one of the most important causes of smog. On the afternoon of December 21, 2016, Chinese President Xi Jinping presided over the fourteenth meeting of the Central Finance and Economics Leading Group and emphasized that “6 issues such as the promotion of clean heating in winter in the northern region are all major issues that affect the lives of the broad masses of people and are of major importance. People's Livelihood Project, People...

AI Technical Summary

Problems solved by technology

However, the air source heat pump is greatly affected by the fluctuation of outdoor temperature, and the output is opposite to the heating and air conditioning load, especially the low temperature environment has a great impact on the performance of the compressor

In addition, the end form of traditional coal-fired heating in rural areas is mostly based on radiators, and the temperature of supply and return water is relatively high. Traditional air source heat pumps cannot meet user requirements

Third, although the newly synthesized refrigerants play a positive role in replacing CFCs and HCFCs refrigerants, studies have shown that these new refrigerants do not meet the requirements of "long-term" replacements, and the life of these substances is either long or short , will increase the greenhouse effect, or decompose to produce other side effects

[0006] However, the study found that the outlet temperature of the gas cooler was higher due to the higher temperature of the supply and return water in the secondary side heat exchange, resulting in CO 2 The throttling loss of the transcritical heat pump unit is relatively large, and the throttling loss increases sharply with the temperature before throttling, which eventually leads to CO 2 The performance of the heat pump heating system decreases, especially when the terminal heat exchange equipment is a radiator

[0007] Looking at the research status at home and abroad, CO 2 Heat pump heating technology has been greatly improved, but the performance in the actual operation process is still unsatisfactory, and the stability and reliability of the system in low temperature environments are far from being resolved

Images