US-20260124875-A1 - HEAT PUMP CYCLE DEVICE

US20260124875A1US 20260124875 A1US20260124875 A1US 20260124875A1US-20260124875-A1

Abstract

A heat pump cycle device includes a control unit that executes control switching between a first heating mode and a second heating mode. In the first heating mode, all refrigerant discharged from a compressor flows into a heating unit via a branch portion. In the second heating mode, a part of the refrigerant discharged from the compressor flows into a bypass passage via the branch portion to be merged with the refrigerant flowing from the heating unit. When switching from the first heating mode to the second heating mode, the control unit executes a limiting operation of limiting an amount of released heat in the heating unit in the first heating mode to a low level, and completes the switching to the second heating mode after executing the limiting operation.

Inventors

Kiyoshiro Ota
Kengo Sugimura
Yuichi Kami

Assignees

DENSO CORPORATION

Dates

Publication Date: 20260507
Application Date: 20251230
Priority Date: 20230703

Claims (15)

1 . A heat pump cycle device comprising: a compressor configured to compress and discharge a refrigerant; a branch portion configured to branch a flow of the refrigerant discharged from the compressor; a heating unit configured to heat a heating target using the refrigerant flowing out of one outflow port of the branch portion as a heat source; a low temperature decompression unit configured to decompress the refrigerant flowing out of the heating unit; a bypass passage configured to allow another portion of the refrigerant branched at the branch portion to flow through the bypass passage; a bypass decompression unit configured to adjust a flow rate of the refrigerant flowing through the bypass passage; a merging portion configured to merge a flow of the refrigerant flowing out of the bypass decompression unit and a flow of the refrigerant flowing out of the low temperature decompression unit to flow out toward a suction port of the compressor; a heat absorption unit configured to cause at least the refrigerant flowing out of the low temperature decompression unit to absorb heat of a heat absorption target; and a control unit including a processor with a memory storing program configured to cause the processor configured to execute control switching between a first heating mode and a second heating mode, the first heating mode configured to cause all of the refrigerant discharged from the compressor to flow into the heating unit via the branch portion, and pump up heat absorbed from the heat absorption target in the heat absorption unit to heat the heating target, the second heating mode configured to cause a part of the refrigerant discharged from the compressor to flow into the bypass passage via the branch portion, guide the refrigerant flowing out of the bypass decompression unit to the merging portion, cause another part of the refrigerant discharged from the compressor to flow into the heating unit via the branch portion, and cause the refrigerant flowing out of the heating unit to merge with a flow of the refrigerant from the bypass decompression unit at the merging portion to be sucked into the compressor, wherein the control unit is configured to, when switching from the first heating mode to the second heating mode, execute a limiting operation of limiting an amount of released heat in the heating unit in the first heating mode to a low level, and complete the switching to the second heating mode after executing the limiting operation.
2 . The heat pump cycle device according to claim 1 , wherein the heating unit includes a radiator configured to release heat of the refrigerant that has flowed into the heating unit, and a supply adjustment unit configured to adjust a supply amount of the heating target to be supplied to the radiator, and the limiting operation includes controlling an operation of the supply adjustment unit to limit a supply amount of the heating target to the radiator to be lower than a predetermined reference amount.
3 . The heat pump cycle device according to claim 1 , wherein the control unit is configured to, when a heating capacity of the heating unit exceeds a predetermined reference heating capacity during the limiting operation, terminate the limiting operation and release limitation of the amount of released heat in the heating unit.
4 . The heat pump cycle device according to claim 1 , wherein the control unit is configured to, when a pressure of the refrigerant in the heat absorption unit exceeds a predetermined reference low pressure during the limiting operation, terminate the limiting operation and release limitation of the amount of released heat in the heating unit.
5 . The heat pump cycle device according to claim 1 , wherein the control unit is configured to, when switching from the first heating mode to the second heating mode, execute a heat absorption-amount securing operation in parallel with the limiting operation, the heat absorption-amount securing operation securing a heat absorption amount in the heat absorption unit using heat of the refrigerant discharged from the compressor and heat absorbed from the heat absorption target in the heat absorption unit, and complete the switching to the second heating mode after executing the heat absorption-amount securing operation and the limiting operation.
6 . A heat pump cycle device comprising: a compressor configured to compress and discharge a refrigerant; a branch portion configured to branch a flow of the refrigerant discharged from the compressor; a heating unit configured to heat a heating target using the refrigerant flowing out of one outflow port of the branch portion as a heat source; a low temperature decompression unit configured to decompress the refrigerant flowing out of the heating unit; a bypass passage configured to allow another portion of the refrigerant branched at the branch portion to flow through the bypass passage; a bypass decompression unit configured to adjust a flow rate of the refrigerant flowing through the bypass passage; a merging portion configured to merge a flow of the refrigerant flowing out of the bypass decompression unit and a flow of the refrigerant flowing out of the low temperature decompression unit to flow out toward a suction port of the compressor; a heat absorption unit configured to cause at least the refrigerant flowing out of the low temperature decompression unit to absorb heat of a heat absorption target; and a control unit including a processor with a memory storing program configured to cause the processor to execute control switching between a first heating mode and a second heating mode, the first heating mode configured to cause all of the refrigerant discharged from the compressor to flow into the heating unit via the branch portion, and pump up heat absorbed from the heat absorption target in the heat absorption unit to heat the heating target, the second heating mode configured to cause a part of the refrigerant discharged from the compressor to flow into the bypass passage via the branch portion, guide the refrigerant flowing out of the bypass decompression unit to the merging portion, cause another part of the refrigerant discharged from the compressor to flow into the heating unit via the branch portion, and cause the refrigerant flowing out of the heating unit to merge with a flow of the refrigerant from the bypass decompression unit at the merging portion to be sucked into the compressor, wherein the control unit is configured to, when switching from the first heating mode to the second heating mode, execute a heat absorption-amount securing operation of securing a heat absorption amount in the heat absorption unit using heat of the refrigerant discharged from the compressor and heat absorbed from the heat absorption target in the heat absorption unit, and complete the switching to the second heating mode after executing the heat absorption-amount securing operation.
7 . The heat pump cycle device according to claim 6 , wherein the heat absorption-amount securing operation is configured to continue absorbing heat from the heat absorption target in the heat absorption unit while operating in the first heating mode, and simultaneously, cause a part of the refrigerant discharged from the compressor to flow into the bypass passage via the branch portion and guide the refrigerant flowing out of the bypass decompression unit to the merging portion.
8 . The heat pump cycle device according to claim 6 , wherein the control unit is configured to reduce heat absorption in the heat absorption unit when a heat absorption stop condition is satisfied during the heat absorption-amount securing operation, the heat absorption stop condition is a condition that a heat absorption amount absorbed by the refrigerant from the heat absorption target in the heat absorption unit is lower than a predetermined reference heat absorption amount.
9 . The heat pump cycle device according to claim 8 , wherein the control unit is configured to reduce heat absorption in the heat absorption unit by reducing a supply amount of the heat absorption target to the heat absorption unit when the heat absorption stop condition is satisfied during the heat absorption-amount securing operation.
10 . The heat pump cycle device according to claim 8 , further comprising a refrigerant bypass flow path through which a flow of the refrigerant flowing out of the heating unit bypasses the heat absorption unit and is guided to the merging portion, wherein the control unit is configured to reduce heat absorption in the heat absorption unit by stopping a supply of the refrigerant to the heat absorption unit using the refrigerant bypass flow path when the heat absorption stop condition is satisfied during the heat absorption-amount securing operation.
11 . A heat pump cycle device comprising: a heat pump cycle including a compressor configured to compress and discharge a refrigerant, a heat-medium refrigerant heat exchanger configured to release heat of a high-pressure refrigerant discharged from the compressor to a heat medium, a decompression unit configured to decompress the refrigerant flowing out of the heat-medium refrigerant heat exchanger, and a chiller configured to cause the refrigerant to absorb heat via heat exchange between the refrigerant decompressed by the decompression unit and the heat medium; a heat medium circuit including a first circuit configured to allow the heat medium flowing out of the heat-medium refrigerant heat exchanger to circulate through the first circuit, the first circuit including a heat medium radiator configured to release heat of the heat medium to a heating target, a second circuit configured to allow the heat medium flowing through the chiller to circulate through the second circuit, the second circuit including a heat medium heat absorber configured to absorb heat from a heat absorption target via heat exchange with the heat medium, a heat-medium connection flow path connected between the first circuit and the second circuit so that the heat medium is allowed to flow in and out, and a flow rate adjustment unit configured to adjust a flow rate of the heat medium flowing in and out between the first circuit and the second circuit via the heat-medium connection flow path; and a control unit including a processor with a memory storing program configured to cause the processor to execute control switching between an independent circulation heating mode and a circuit cooperation heating mode, the independent circulation heating mode configured to cause the heat medium to independently circulate through the second circuit and absorb heat derived from the heat absorption target to be pumped up by the heat pump cycle, and cause the heat medium to independently circulate through the first circuit and heat the heating target in the heat medium radiator using the heat pumped up, the circuit cooperation heating mode configured to cause a part of the heat medium flowing out of the heat-medium refrigerant heat exchanger to flow through the chiller via the heat-medium connection flow path, and cause another part of the heat medium flowing out of the heat-medium refrigerant heat exchanger to circulate through the first circuit via the heat medium radiator to heat the heating target in the heat medium radiator, wherein the control unit is configured to, when switching from the independent circulation heating mode to the circuit cooperation heating mode, execute a limiting operation of limiting an amount of released heat in the heat medium radiator in the independent circulation heating mode to a low level, and complete the switching to the circuit cooperation heating mode after executing the limiting operation.
12 . The heat pump cycle device according to claim 11 , further comprising a supply adjustment unit configured to adjust a supply amount of the heating target to be supplied to the heat medium radiator, wherein the limiting operation includes controlling an operation of the supply adjustment unit to limit a supply amount of the heating target to the heat medium radiator to be lower than a predetermined reference amount.
13 . The heat pump cycle device according to claim 11 , wherein the control unit is configured to, when a heating capacity of the heat medium circulating through the first circuit exceeds a predetermined reference during the limiting operation, terminate the limiting operation and release limitation of the amount of released heat in the heat medium radiator.
14 . The heat pump cycle device according to claim 11 , wherein the control unit is configured to, when a pressure of the refrigerant in the chiller exceeds a predetermined reference low pressure during the limiting operation, terminate the limiting operation and release limitation of the amount of released heat in the heat medium radiator.
15 . The heat pump cycle device according to claim 11 , wherein the control unit is configured to, when switching from the independent circulation heating mode to the circuit cooperation heating mode, execute a heat absorption-amount securing operation in parallel with the limiting operation, the heat absorption-amount securing operation securing a heat absorption amount in the chiller using heat absorbed from the heat absorption target in the heat medium heat absorber and heat of the heat medium guided from the first circuit to the chiller via the heat-medium connection flow path, and complete the switching to the circuit cooperation heating mode after executing the heat absorption-amount securing operation and the limiting operation.

Description

CROSS REFERENCE TO RELATED APPLICATIONS The present application is a continuation application of International Patent Application No. PCT/JP2024/018517 filed on May 20, 2024, which designated the U.S. and claims the benefit of priority from Japanese Patent Application No. 2023-109418 filed on Jul. 3, 2023. The disclosures of all the above applications are incorporated herein. TECHNICAL FIELD The present disclosure relates to a heat pump cycle device. BACKGROUND Conventionally, techniques have been developed in which a heat pump cycle device is applied to vehicle air conditioners, enabling a heat pump heating mode that heats a heating target using heat absorbed from an external heat absorption source. SUMMARY According to a first aspect of the present disclosure, a heat pump cycle device includes a compressor, a branch portion, a heating unit, a low temperature decompression unit, a bypass passage, a bypass decompression unit, a merging portion, a heat absorption unit, and a control unit. The compressor is configured to compress and discharge a refrigerant. The branch portion is configured to branch a flow of the refrigerant discharged from the compressor. The heating unit is configured to heat a heating target using the refrigerant flowing out of one outflow port of the branch portion as a heat source. The low temperature decompression unit is configured to decompress the refrigerant flowing out of the heating unit. The bypass passage is configured to allow another portion of the refrigerant branched at the branch portion to flow through the bypass passage. The bypass decompression unit is configured to adjust a flow rate of the refrigerant flowing through the bypass passage. The merging portion is configured to merge a flow of the refrigerant flowing out of the bypass decompression unit and a flow of the refrigerant flowing out of the low temperature decompression unit to flow out toward a suction port of the compressor. The heat absorption unit is configured to cause at least the refrigerant flowing out of the low temperature decompression unit to absorb heat of a heat absorption target. The control unit includes a processor with a memory storing a program configured to cause the processor to execute control switching between a first heating mode and a second heating mode. The first heating mode is configured to cause all of the refrigerant discharged from the compressor to flow into the heating unit via the branch portion, and pump up heat absorbed from the heat absorption target in the heat absorption unit to heat the heating target. The second heating mode is configured to cause a part of the refrigerant discharged from the compressor to flow into the bypass passage via the branch portion, and guide the refrigerant flowing out of the bypass decompression unit to the merging portion. Simultaneously, the second heating mode is configured to cause another part of the refrigerant discharged from the compressor to flow into the heating unit via the branch portion, and cause the refrigerant flowing out of the heating unit to merge with a flow of the refrigerant from the bypass decompression unit at the merging portion to be sucked into the compressor. The control unit is configured to, when switching from the first heating mode to the second heating mode, execute a limiting operation of limiting an amount of released heat in the heating unit in the first heating mode to a low level, and complete the switching to the second heating mode after executing the limiting operation. BRIEF DESCRIPTION OF DRAWINGS The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features and advantages will be apparent from the description and drawings, and from the claims. FIG. 1 is a configuration diagram of a heat pump cycle device according to a first embodiment. FIG. 2 is a configuration diagram of an interior air conditioning unit according to the first embodiment. FIG. 3 is a block diagram illustrating a control system of the heat pump cycle device according to the first embodiment. FIG. 4 is a Mollier diagram of the heat pump cycle device according to the first embodiment during a heat pump heating. FIG. 5 is a Mollier diagram of the heat pump cycle device according to the first embodiment during a hot gas heating. FIG. 6 is an explanatory diagram illustrating an example of switching control of the heat pump cycle device according to the first embodiment. FIG. 7 is a configuration diagram of a heat pump cycle device according to a second embodiment. FIG. 8 is an explanatory diagram illustrating a first state in switching control of the heat pump cycle device according to the second embodiment. FIG. 9 is an explanatory diagram illustrating a second state in switching control of the heat pump cycle device according to the second embodiment. FIG. 10 is a configuration diagram of a heat pump cycle device according to a third embodiment. FIG. 11 is an explanatory dia