Refrigeration cycle device

Abstract

This refrigeration cycle device comprises: a low temperature side pump (11) which takes in and discharges a low temperature side heat carrier; a compressor (21) which takes in, compresses, and discharges a refrigerant; a heat dissipating unit (15) which dissipates heat from high-pressure refrigerant discharged from the compressor (21); a pressure reducing device (23c) which reduces the pressure of the high-pressure refrigerant for which the heat has been dissipated by the heat dissipating unit (15); an internal heat exchanger (24) which exchanges heat between the high-pressure refrigerant flowing from the heat dissipating unit (15) and low-pressure refrigerant discharged from a heat carrier cooling unit (14); a low-pressure refrigerant temperature sensing unit (23a) which detects or senses the temperature associated with the temperature of the low-pressure refrigerant that exchanged heat in the internal heat exchanger (24); and an overheating control unit (23b) which controls the degree of overheating of the low-pressure refrigerant that exchanged heat in the internal heat exchanger (24) on the basis of the temperature detected or sensed by the low-pressure refrigerant temperature sensing unit (23a).

Description

[0001] Cross-references to related applications [0002] This application is based on the JP Patent application 2014-125306 for which it applied on June 18, 2014, The content of an indication is incorporated in this application as a reference. technical field [0003] The present invention relates to a refrigeration cycle device provided with an internal heat exchanger. Background technique [0004] Conventionally, Patent Document 1 describes a refrigeration cycle apparatus that uses carbon dioxide as a refrigerant and includes an internal heat exchanger. The internal heat exchanger is a heat exchanger that exchanges heat between the refrigerant from the radiator and the refrigerant from the evaporator. [0005] When carbon dioxide is used as the refrigerant, the pressure on the high pressure side becomes higher than the critical pressure in summer, and the power consumption of the compressor increases, thereby deteriorating the cooling coefficient (COP) of the refrigeratio...

AI Technical Summary

Problems solved by technology

[0014] In the case where the evaporator achieves the same degree of superheat as in the prior art, in the evaporator of the above prior art, since the difference between the temperature of the blown air and the temperature of the refrigerant is large, it is possible to use a relatively small heat exchange area. A specified amount of superheat is obtained, but in the evaporator of this research example, since it is necessary to obtain superheat between the refrigerant and the cooling water whose temperature is very low relative to the supply air, it is difficult to obtain superheat and there is a refrigeration cycle Concerns about deterioration of controllability (variation suppression, stability) when the load fluctuates

[0015] In addition, when the degree of superheat is obtained in a state where the temperature difference between the refrigerant and the cooling water is small, it is necessary to increase the temperature difference between the refrigerant and the cooling water by lowering the temperature of the refrigerant in the evaporator so that the heat exchange amount increase, but in this case, there is a concern that the refrigerant density sucked into the compressor will decrease and the cooling coefficient (COP) of the refrigeration cycle will deteriorate.

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