Engine heat pump

Abstract

An object of the invention is to provide an engine heat pump whose compression work is reduced without increase of consumed electric power, thereby improving its driving efficiency (energy efficiency). An engine heat pump comprises: an engine (4); a main compressor (2) driven by the engine (4); a sub compressor (3); an indoor heat exchanger (8); an outdoor heat exchanger (5); an expansion valve (23) for the indoor heat exchanger; an expansion valve (21) for the outdoor heat exchanger; and a supercooling heat exchanger (15) disposed on a liquid refrigerant passage (main passage 26) of a connection passage between the indoor heat exchanger (8) and the outdoor heat exchanger (5). In the supercooling heat exchanger (15), a supercooling liquid refrigerant branched into a branching passage (27(27a, 27b)) supercools a liquid refrigerant before being branched. The sub compressor (3) is driven by the engine (4) so as to compress the supercooling liquid refrigerant. A ratio (R) of a capacity of the sub compressor (3) to a total capacity of the main compressor (2) and the sub compressor (3) ranges between 20% and 29%.

Description

technical field [0001] The present invention relates to a device structure of an engine heat pump, and more specifically, relates to a technique for reducing total compression work without increasing new power consumption. Background technique [0002] Regarding an engine heat pump in which an engine drives a compressor, the structure described in Patent Document 1 is known. In Patent Document 1, an invention is disclosed that divides the compression work of the engine heat pump into two systems of compression work produced by the main compressor and that produced by the auxiliary compressor, by dividing one side (the auxiliary compressor side) at a higher pressure than the other side (main compressor side), reducing the compression work on said side, thereby reducing the total compression work in the engine heat pump. [0003] In the aforementioned Patent Document 1, a structure is disclosed in which an electrically driven compressor (electric compressor) is used to perfor...

AI Technical Summary

Problems solved by technology

[0003] In the aforementioned Patent Document 1, a structure is disclosed in which an electrically driven compressor (electric compressor) is used to perform compression work on the side (auxiliary compressor side) where the evaporation pressure becomes high pressure. However, in this structure In the engine heat pump, additional equipment that requires new power (the aforementioned electric compressor) is installed

In this case, although the compression work is reduced, the power consumption is increased, resulting in the inability to fully produce the original advantages of the so-called "reduced power consumption" of the engine heat pump.

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