Heat pump system

Patent metadata

Field	Value
Publication number	US-11179999-B2
Application number	US-201615749514-A
Country	US
Kind code	B2
Filing date	Jul 12, 2016
Priority date	Aug 4, 2015
Publication date	Nov 23, 2021
Grant date	Nov 23, 2021

Abstract

A heat pump system includes a compressor that compresses and discharges a refrigerant, a decompressor that decompresses the refrigerant, an outdoor unit that exchanges heat between the refrigerant and an outside air, an evaporator that evaporates the refrigerant, a condenser that condenses the refrigerant, an internal heat exchanger, an accumulator that separates the refrigerant into a gas refrigerant and a liquid refrigerant, and a flow pathway changing portion. The internal heat exchanger includes a high-pressure passage through which a high-pressure refrigerant flows, and a low-pressure passage through which a low-pressure refrigerant flows, the internal heat exchanger exchanging heat between the refrigerant flowing through the high-pressure passage and the refrigerant flowing through the low-pressure passage. The flow pathway changing portion that switches between a cooling pathway and a heating pathway. According to this heat pump system, a cooling capacity and a heating capacity can be improved.

First claim

What is claimed is:

1. A heat pump system comprising: a compressor that compresses and discharges a refrigerant; a decompressor that decompresses the refrigerant; an outdoor heat exchanger that exchanges heat between the refrigerant and an outside air; an evaporator that evaporates the refrigerant; a condenser that condenses the refrigerant; an internal heat exchanger that includes a high-pressure passage through which a high-pressure refrigerant flows, and a low-pressure passage through which a low-pressure refrigerant flows, the internal heat exchanger exchanging heat between the refrigerant flowing through the high-pressure passage and the refrigerant flowing through the low-pressure passage; an accumulator that separates the refrigerant into a gas refrigerant and a liquid refrigerant; and a flow pathway changing portion that switches a pathway in which the refrigerant flows, wherein the flow pathway changing portion switches between a cooling pathway and a heating pathway, in the cooling pathway, the refrigerant circulates, in order, from the compressor, to the outdoor heat exchanger, directly to the condenser, to the high-pressure passage of the internal heat exchanger, to the decompressor, to the evaporator, to the accumulator, to the low-pressure passage of the internal heat exchanger, then back to the compressor, in the heating pathway, the refrigerant circulates, in order, from the compressor, to the condenser, to the high-pressure passage of the internal heat exchanger, to the decompressor, to the outdoor heat exchanger, to the accumulator, to the low-pressure passage of the internal heat exchanger, then back to the compressor, the accumulator includes a gas refrigerant passage through which the separated gas refrigerant flows out, and a liquid refrigerant passage through which the separated liquid refrigerant flows out, and in the gas refrigerant passage and the liquid refrigerant passage, at least the liquid refrigerant passage is connected to the low-pressure passage of the internal heat exchanger.

2. The heat pump system according to claim 1 , further comprising:
a flow rate regulator that adjusts a flow rate of the liquid refrigerant flowing from the accumulator to the internal heat exchanger.

3. The heat pump system according to claim 2 , wherein
the liquid refrigerant passage is connected to the low-pressure passage of the internal heat exchanger, and
the gas refrigerant passage is connected to a downstream side of the low-pressure passage of the internal heat exchanger.

4. The heat pump system according to claim 2 , wherein
the outdoor heat exchanger includes an upper port and a lower port through which the refrigerant flows, the lower port being located downward of the upper port,
in the cooling pathway, the refrigerant flows into the outdoor heat exchanger through the upper port, and
in the heating pathway, the refrigerant flows into the outdoor heat exchanger through the lower port.

5. The heat pump system according to claim 2 , wherein
the outdoor heat exchanger is downflow-type that includes an upper tank, a lower tank, and a core portion,
the outdoor heat exchanger includes
an upper port provided in the upper tank, the refrigerant flowing through the upper port, and
a lower port provided in the lower tank, the refrigerant flowing through the lower port,

in the cooling pathway, the refrigerant flows into the outdoor heat exchanger through the upper port, and the refrigerant flows out of the outdoor heat exchanger through the lower port,
in the heating pathway, the refrigerant flows into the outdoor heat exchanger through the lower port, and the refrigerant flows out of the outdoor heat exchanger through the upper port.

6. The heat pump system according to claim 2 , further comprising:
a control unit that controls the flow rate regulator, wherein
in the heating pathway, the control unit estimates a superheat based on physical properties of the refrigerant that is to be drawn into the compressor, and
the control unit controls the flow rate regulator such that the superheat approaches a predetermined target value.

7. A heat pump system comprising:
a compressor that compresses and discharges a refrigerant;
a decompressor that decompresses the refrigerant;
an outdoor heat exchanger that exchanges heat between the refrigerant and an outside air;
an evaporator that evaporates the refrigerant;
a condenser that condenses the refrigerant;
an internal heat exchanger that includes
a high-pressure passage through which a high-pressure refrigerant flows, and
a low-pressure passage through which a low-pressure refrigerant flows, the internal heat exchanger exchanging heat between the refrigerant flowing through the high-pressure passage and the refrigerant flowing through the low-pressure passage;

an accumulator that separates the refrigerant into a gas refrigerant and a liquid refrigerant;
a flow pathway changing portion that switches a pathway in which the refrigerant flows; and
a controller that includes a processor and a memory, wherein
the accumulator includes a gas refrigerant passage through which the separated gas refrigerant flows out, and a liquid refrigerant passage through which the separated liquid refrigerant flows out,
in the gas refrigerant passage and the liquid refrigerant passage, at least the liquid refrigerant passage is connected to the low-pressure passage of the internal heat exchanger,
the flow pathway changing portion switches between the cooling pathway, a first heating pathway, a second heating pathway, a first dehumidification-heating pathway, a second dehumidification-heating pathway, and a defrosting pathway,
the processor is programmed to control the flow pathway changing portion such that:
in the cooling pathway, the refrigerant circulates, in order, from the compressor, to the outdoor heat exchanger, to the high-pressure passage of the internal heat exchanger, to the decompressor, to the evaporator, to the accumulator, to the low-pressure passage of the internal heat exchanger, then back to the compressor;
in the first heating pathway, the refrigerant circulates, in order, from the compressor, to the condenser, to the high-pressure passage of the internal heat exchanger, to the decompressor, to the outdoor heat exchanger, to the accumulator, to the low-pressure passage of the internal heat exchanger, then back to the compressor;
in the second heating pathway, the refrigerant circulates, in order, from the compressor, to the condenser, to the evaporator, to the accumulator, to the low-pressure passage of the internal heat exchanger, then back to the compressor; and
in the first dehumidification-heating pathway, the refrigerant circulates, in order, from the compressor, to the condenser, to the high-pressure passage of the internal heat exchanger, to the decompressor, to the outdoor heat exchanger, to the accumulator, to the low-pressure passage of the internal heat exchanger, then back to the compressor,

the first dehumidification-heating pathway includes a route in which the refrigerant is branched at a part located downstream of the condenser to flow into the accumulator via the evaporator, not via the high-pressure passage,
the processor is programmed to control the flow pathway changing portion such that:
in the second dehumidification-heating pathway, the refrigerant circulates, in order, from the compressor, to the outdoor heat exchanger, to the high-pressure passage of the internal heat exchanger, to the decompressor, to the evaporator, to the accumulator, to the low-pressure passage of the internal heat exchanger, then back to the compressor,

the second dehumidification-heating pathway includes a route in which the refrigerant is branched at a part located downstream of the compres

Assignees

• Denso Corp

Inventors

• Mieda Hiroshi
• Sugimura Ryohei
• Kawakubo Masaaki
• Kami Yuichi

Classifications

• B60H1/22 Primary

  the heat source being other than the propulsion plant {(B60H1/00492 takes precedence)} · CPC title

• F25B41/24 Primary

  Arrangement of shut-off valves for disconnecting a part of the refrigerant cycle, e.g. an outdoor part · CPC title

• F25B25/005

  using primary and secondary systems · CPC title

• F25B40/00

  Subcoolers, desuperheaters or superheaters · CPC title

• F25B2600/2507

  Flow-diverting valves · CPC title