Vehicular heat pump system

Patent metadata

Field	Value
Publication number	US-10752092-B2
Application number	US-201615558210-A
Country	US
Kind code	B2
Filing date	Mar 15, 2016
Priority date	Mar 16, 2015
Publication date	Aug 25, 2020
Grant date	Aug 25, 2020

Abstract

The present invention relates to a vehicular heat pump system and, more specifically, to a vehicular heat pump system having a chiller for heat exchanging cooling water circulating through vehicle electrical equipment ( 200 ), a refrigerant discharged from an outdoor heat exchanger so as to flow through a first bypass line (R 1 ), and a refrigerant discharged from an indoor heat exchanger, thereby: in the air conditioner mode, increasing sub-cool while the refrigerant discharged from the indoor heat exchanger is first cooled at the chiller and then is second cooled at the outdoor heat exchanger such that the flow rate of refrigerants increases and cooling performance is improved; in the heat pump mode, allowing the refrigerant discharged from the indoor heat exchanger to ensure sub-cool in the chiller so as to increase the flow rate of refrigerants, and allowing the refrigerant discharged from the outdoor heat exchanger to receive an additional heating source from the chiller so as to improve heating performance; and, even in the defrost mode carried out because of frost on the outdoor heat exchanger, ensuring an additional heating source in the chiller so as to minimize a change in indoor discharge temperature because of a lack of heating sources.

First claim

What is claimed is:

1. A vehicular heat pump system, which comprises: a compressor mounted on a refrigerant circulation line for compressing and discharging refrigerant; an indoor heat exchanger mounted inside an air-conditioning case for exchanging heat between air inside the air-conditioning case and the refrigerant discharged from the compressor; an evaporator mounted inside the air-conditioning case for exchanging heat between the air inside the air-conditioning case and refrigerant supplied to the compressor; an outdoor heat exchanger mounted outside the air-conditioning case for exchanging heat between the refrigerant circulating through the refrigerant circulation line and outdoor air; a first expansion valve mounted on the refrigerant circulation line at an inlet of the outdoor heat exchanger; and a second expansion valve mounted on the refrigerant circulation line at an inlet side of the evaporator to expand the refrigerant, further comprising:
a first bypass line connecting the refrigerant circulation line at an inlet side of the second expansion valve with the refrigerant circulation line at an outlet side of the evaporator, such that the refrigerant circulating through the first bypass line bypasses the second expansion valve and the evaporator;
a first direction changing valve mounted at a branch point of the refrigerant circulation line and the first bypass line; and
a chiller for exchanging heat between coolant which circulates through vehicle electronic units, refrigerant which flows through the first bypass line, and refrigerant which is discharged from the indoor heat exchanger;
wherein the chiller includes a coolant heat exchanger connected with the vehicle electronic units through a coolant line, a first refrigerant heat exchanger connected with the first bypass line, and a second refrigerant heat exchanger connected with the refrigerant circulation line of an outlet side of the indoor heat exchanger and an inlet side of the first expansion valve;
wherein a flow of the refrigerant circulating through the heat pump system is controlled by the first direction changing valve depending on an air-conditioning mode and a heat pump mode;
wherein in the air-conditioning mode, the first direction changing valve closes flow in the refrigerant circulation line from the outdoor heat exchanger to the first bypass line and opens flow in the refrigerant circulation line from the outdoor heat exchanger toward the second expansion valve such that the refrigerant discharged from the compressor circulates through the indoor heat exchanger, the second refrigerant heat exchanger of the chiller, the outdoor heat exchanger, the second expansion valve, and the evaporator in order;
wherein in the heat pump mode, the first direction changing valve opens flow in the refrigerant circulation line from the outdoor heat exchanger to the first bypass line and closes flow in the refrigerant circulation line from the outdoor heat exchanger toward the second expansion valve such that the refrigerant discharged from the compressor circulates through the indoor heat exchanger, the second refrigerant heat exchanger of the chiller, the first expansion valve, the outdoor heat exchanger and the first refrigerant heat exchanger of the chiller in order;
wherein in the air-conditioning mode, the refrigerant of high-temperature and high-pressure discharged from the indoor heat exchanger is first cooled in the chiller, and then, is second cooled in the outdoor heat exchanger so as to increase subcooling and expand the refrigerant flow rate, thereby improving cooling performance and reducing power consumption;
wherein in the heat pump mode, the refrigerant of high-temperature and high-pressure discharged from the indoor heat exchanger ensures subcooling through heat exchange with the refrigerant discharged from the outdoor heat exchanger in the chiller so as to increase the refrigerant flow rate, and the refrigerant of low-temperature and low-pressure discharged from the outdoor heat exchanger receives additional heat source from the chiller so as to increase heating performance;
wherein the chiller condenses the refrigerant in the air-conditioning mode, and the chiller condenses the refrigerant discharged from the indoor heat exchanger and evaporates the refrigerant discharged from the outdoor heat exchanger in the heat pump mode.

2. The vehicular heat pump system according to claim 1 , wherein the chiller is configured in such a way that the first refrigerant heat exchanger is arranged between the coolant heat exchanger and the second refrigerant heat exchanger, and
wherein the refrigerant which is discharged from the outdoor heat exchanger and flows through the first refrigerant heat exchanger exchanges heat between the coolant of the coolant heat-exchanging unit and the refrigerant of the second refrigerant heat exchanger.

3. The vehicular heat pump system according to claim 1 , wherein a second bypass line is mounted on the refrigerant circulation line to connect the refrigerant circulation lines of the inlet and outlet sides of the outdoor heat exchanger, such that the refrigerant circulating through the refrigerant circulation line bypasses the outdoor heat exchanger, and
wherein the first bypass line and the second bypass line are mounted in parallel on the refrigerant circulation line.

4. The vehicular heat pump system according to claim 3 , wherein, on the refrigerant circulation line, a second direction changing valve is mounted at a point where the second bypass line is branched, and
wherein a flow of the refrigerant circulating through the heat pump system is controlled by the first direction changing valve and the second direction changing valve depending on the air-conditioning mode and the heat pump mode.

5. The vehicular heat pump system according to claim 4 , wherein, in the heat pump mode, when it is detected that frosting has occurred on the outdoor heat exchanger, the refrigerant flow is controlled in such a way that the refrigerant passing through the first expansion valve flows to the second bypass line so as to bypass the outdoor heat exchanger.

6. The vehicular heat pump system according to claim 1 , further comprising:
a dehumidification line for connecting the refrigerant circulation line at the inlet side of the evaporator with the refrigerant circulation line at the outlet side of the first expansion valve.

7. The vehicular heat pump system according to claim 6 , wherein an on-off valve is mounted on the dehumidification line.

8. The vehicular heat pump system according to claim 7 , wherein, in a dehumidification mode during operation of the heat pump mode, the refrigerant passing through the compressor, the indoor heat exchanger, the chiller and the first expansion valve is divided into two, and, some of the divided refrigerant circulates toward the outdoor heat exchanger and the first bypass line and some of the refrigerant circulates toward the dehumidification line and the evaporator, and then, the divided refrigerants meet together at the inlet side of the compressor.

9. The vehicular heat pump system according to claim 1 , wherein the first expansion valve comprises: an on-off valve which makes a refrigerant passage on or off by operating a valve member through a solenoid; and an orifice formed at the valve member,
wherein the first expansion valve makes the refrigerant flow in an unexpanded state through the passage when the valve member opens the passage and makes the refrigerant flow in an expanded state through the orifice when the valve member closes the passage.

Assignees

• Hanon Systems

Inventors

• Choi Young Ho
• Maeng Chan Joo
• Lee Seung Ho
• Lee Jung Jae
• Kim Hak Kyu
• Kang Sung Ho
• Lee Jae Min

Classifications

• F25B41/20

  Disposition of valves, e.g. of on-off valves or flow control valves (expansion valves F25B41/31) · CPC title

• F25B2400/0409

  for evaporators · CPC title

• F25B5/04

  arranged in series · CPC title

• F25B30/02

  of the compression type · CPC title

• B60H1/3213 Primary

  for increasing the efficiency in a vehicle heat pump · CPC title