Apparatus using a heat pump including a refrigerant leakage detector

Patent metadata

Field	Value
Publication number	US-11248829-B2
Application number	US-201716490744-A
Country	US
Kind code	B2
Filing date	Jun 9, 2017
Priority date	Jun 9, 2017
Publication date	Feb 15, 2022
Grant date	Feb 15, 2022

Abstract

An apparatus using a heat pump includes a refrigerant circuit and a heat medium circuit. The refrigerant circuit is capable of performing a first operation, in which a load-side heat exchanger is used as a condenser, and a second operation, in which the load-side heat exchanger is used as an evaporator. A main circuit of the heat medium circuit has a branching part and a joining part. An overpressure protection device and a refrigerant leakage detecting device are connected to the main circuit. The overpressure protection device is connected to a connection part located between the load-side heat exchanger and one of the branching part and the joining part, or at the load-side heat exchanger. When leakage of refrigerant is detected, the state of a refrigerant flow switching device is set to a second state, an expansion device is set to a closed state, and a compressor is operated.

First claim

The invention claimed is:

1. An apparatus using a heat pump, the apparatus comprising:
a refrigerant circuit including a compressor, a refrigerant flow switcher, a heat-source-side heat exchanger, an expansion device, and a load-side heat exchanger, the refrigerant circuit being configured to circulate refrigerant; and
a heat medium circuit configured to cause a heat medium to flow via the load-side heat exchanger,
the refrigerant flow switcher being configured in such a manner that a state of the refrigerant flow switcher is switchable between a first state and a second state,
the refrigerant circuit being configured to perform a first operation in which the load-side heat exchanger is used as a condenser in response to the state of the refrigerant flow switcher being switched to the first state,
the refrigerant circuit being configured to perform a second operation in which the load-side heat exchanger is used as an evaporator in response to the state of the refrigerant flow switcher being switched to the second state,
the heat medium circuit including a main circuit extending via the load-side heat exchanger,
the main circuit including
a branching part provided at a downstream end of the main circuit, the branching part being a part at which a plurality of branch circuits that branch off from the main circuit are connected, and
a joining part provided at an upstream end of the main circuit, the joining part being a part at which the plurality of branch circuits are connected to join the main circuit,
to the main circuit, an overpressure protector and a refrigerant leakage detector being connected, the refrigerant leakage detector being configured to detect leakage of the refrigerant into the heat medium circuit,
in the main circuit, the overpressure protector being connected to a connection part that is located between the load-side heat exchanger and one of the branching part and the joining part or at the load-side heat exchanger,
in the main circuit, the refrigerant leakage detector being connected to an other of the branching part and the joining part, between the connection part and the other of the branching part and the joining part, or at the connection part,
wherein the refrigerant flow switcher is configured to be set to the second state, the expansion device is configured to be set to a closed state, and the compressor is configured to be operated in response to the refrigerant leakage detector detecting leakage of the refrigerant into the heat medium circuit, and
wherein the refrigerant circuit is configured to subsequently stop the operation of the compressor in response to a pressure of the heat medium circuit falling below a first threshold pressure or a pressure of the heat medium circuit being on a downward trend.

2. The apparatus using a heat pump of claim 1 , wherein the refrigerant circuit further includes a blocker that is provided, in the refrigerant circuit, between the load-side heat exchanger and the refrigerant flow switcher, at a suction pipe between the refrigerant flow switcher and the compressor, at a discharge pipe between the refrigerant flow switcher and the compressor, between the refrigerant flow switcher and the heat-source-side heat exchanger, or at the compressor.

3. The apparatus using a heat pump of claim 1 , wherein the refrigerant circuit further includes a blocker that is provided, in the refrigerant circuit, at a suction pipe between the refrigerant flow switcher and the compressor, at a discharge pipe between the refrigerant flow switcher and the compressor, or at the compressor, and that is a check valve.

4. An apparatus using a heat pump, the apparatus comprising:
a refrigerant circuit including a compressor, a heat-source-side heat exchanger that is used as a condenser, an expansion device, and a load-side heat exchanger that is used as an evaporator, the refrigerant circuit being configured to circulate refrigerant; and
a heat medium circuit configured to cause a heat medium to flow via the load-side heat exchanger,
the heat medium circuit including a main circuit extending via the load-side heat exchanger,
the main circuit including
a branching part provided at a downstream end of the main circuit, the branching part being a part at which a plurality of branch circuits that branch off from the main circuit are connected, and
a joining part provided at an upstream end of the main circuit, the joining part being a part at which the plurality of branch circuits are connected to join the main circuit,
to the main circuit, an overpressure protector and a refrigerant leakage detector being connected, the refrigerant leakage detector being configured to detect leakage of the refrigerant into the heat medium circuit,
in the main circuit, the overpressure protector being connected to a connection part that is located between the load-side heat exchanger and one of the branching part and the joining part or at the load-side heat exchanger,
in the main circuit, the refrigerant leakage detector being connected to an other of the branching part and the joining part, between the connection part and the other of the branching part and the joining part, or at the connection part,
the expansion device being set to a closed state and the compressor being made in operation, when the refrigerant leakage detector detects leakage of the refrigerant into the heat medium circuit,
wherein the refrigerant leakage detector is configured to detect a leakage of the refrigerant into the heat medium circuit in response to a value selected from one of an inner pressure of the heat medium circuit and a change of the inner pressure of the heat medium circuit with time.

5. The apparatus using a heat pump of claim 4 , wherein the refrigerant circuit further includes a blocker that is provided, in the refrigerant circuit, between the load-side heat exchanger and the compressor, between the compressor and the heat-source-side heat exchanger, or at the compressor.

6. The apparatus using a heat pump of claim 5 , wherein the blocker is a check valve.

7. The apparatus using a heat pump of claim 3 , wherein the check valve is a discharge valve provided at the compressor or a check valve provided at the compressor.

8. The apparatus using a heat pump of claim 1 , wherein, when a pressure of the heat medium circuit exceeds a second threshold pressure or when a pressure of the heat medium circuit is on an upward trend, the compressor that is in a stopped state is restarted.

9. The apparatus using a heat pump of claim 4 , wherein, when a requirement for ending an operation is satisfied, the compressor that is in operation is stopped.

10. The apparatus using a heat pump of claim 9 , wherein the requirement for ending the operation is a requirement that a pressure of the heat medium circuit falls below a first threshold pressure or is on a downward trend.

11. The apparatus using a heat pump of claim 9 , wherein, when a pressure of the heat medium circuit exceeds a second threshold pressure or when a pressure of the heat medium circuit is on an upward trend, the compressor that is in a stopped state is restarted.

12. An apparatus using a heat pump, the apparatus comprising:
a refrigerant circuit including a compressor, a refrigerant flow switcher, a heat-source-side heat exchanger, an expansion device, and a load-side heat exchanger, the refrigerant circuit being configured to circulate refrigerant; and
a heat medium circuit configured to cause a heat medium to flow via the load-side heat exchanger,
the refrigerant flow switcher being configured in such a manner that a state of the refrigerant flow switcher is switchable between a first state and a sec

Assignees

• Mitsubishi Electric Corp

Inventors

• Suzuki Yasuhiro
• Minamisako Hirokazu
• Suzuki Kazutaka
• Mito Takafumi
• Hattori Taro

Classifications

• F25B2339/047

  Water-cooled condensers · CPC title

• F25B47/025

  by reversing the cycle · CPC title

• F24D11/02

  using heat pumps · CPC title

• F25B2400/12

  Inflammable refrigerants · CPC title

• F25B13/00 Primary

  Compression machines, plants or systems, with reversible cycle (defrosting cycles F25B47/02) · CPC title