Air-supply-adjustable quasi-two-stage compression gas heat pump unit suitable for severe cold areas

Abstract

The invention discloses a gas supply adjustable quasi two-stage compression gas heat pump unit suitable for severe cold areas. The gas heat pump unit comprises a quasi-secondary compressor, an indoor heat exchanger, a first electronic expansion valve, a second electronic expansion valve, a third electronic expansion valve, a fourth electronic expansion valve, an outdoor heat exchanger, a low-temperature cooling liquid heat exchanger, a flue gas heat exchanger, a gas-liquid separator, a high-temperature cooling liquid heat exchanger, a gas engine and a cooling liquid circulating pump. A scroll compressor with a middle air supply port is adopted, and after being throttled, a part of refrigerant absorbs heat in a high-temperature cooling liquid heat exchanger to be evaporated into gas, and the gas enters the middle air supply port of the compressor; and the other part of refrigerant enters the evaporator, the low-temperature cooling liquid heat exchanger and the flue gas heat exchanger to absorb heat and be evaporated into gas refrigerant and enters an air suction port of the compressor. The exhaust temperature of the compressor is reduced through intermediate air supply, it is guaranteed that the heat pump operates efficiently and stably at the low temperature, the exhaust temperature does not exceed 120 DEG C, and the COP reaches 1.2 or above.

Description

technical field [0001] The invention relates to a gas-fired heat pump unit, in particular to a gas-supplied adjustable quasi-two-stage compression gas-fired heat pump unit suitable for severe cold regions. Background technique [0002] The gas heat pump drives the compressor through the gas engine, which is a high-efficiency and energy-saving device that significantly improves the utilization rate of primary energy. However, the existing gas heat pump unit can only recover the waste heat of the gas engine under low temperature conditions (below -10°C), but cannot recover the waste heat of the flue gas. Due to the limitation of the compressor and exhaust temperature, the outdoor air evaporator cannot absorb air. The heat makes the exhaust gas temperature higher (over 80 ℃), and the efficiency is lower (COP is only about 85%), which cannot save energy. In this way, due to insufficient heat exchange and heat recovery of the outdoor evaporator at low temperature, the actual wat...

AI Technical Summary

Problems solved by technology

However, when the existing gas heat pump unit works at low temperature (below -10°C), it can only recover the waste heat of the gas engine, but cannot recover the waste heat of the flue gas. Due to the limitation of the compressor and exhaust temperature, it cannot absorb air through the outdoor air evaporator. The heat makes the exhaust gas temperature higher (over 80°C), the efficiency is lower (COP is only about 85%), and it cannot save energy

In this way, at low temperature, due to insufficient heat exchange and heat recovery of the outdoor evaporator, the actual water supply temperature of the system is lower than the set temperature. Increase

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