Heat pump with hot water storage and refrigerant leak detection

An apparatus using a heat pump, the apparatus comprising:

• a refrigerant circuit including a compressor, a refrigerant flow switching valve, a heat-source-side heat exchanger, an expansion valve, a load-side heat exchanger, and a container, the refrigerant circuit being configured to circulate refrigerant;
• a heat medium circuit and pump configured to cause a heat medium to flow via the load-side heat exchanger;
• and
• a controller;
• the refrigerant flow switching valve being configured in such a manner that a state of the refrigerant flow switching valve is switchable between a first state and a second state,
• the controller is configured to
• control the refrigerant flow switching valve to switch between the first state and the second state,
• control the refrigerant circuit to perform a first operation in which the load-side heat exchanger is used as a condenser, when the state of the refrigerant flow switching valve is switched to the first state, and
• control the refrigerant circuit to perform a second operation in which the load-side heat exchanger is used as an evaporator, when the state of the refrigerant flow switching valve is switched to the second state,
• the container being provided to a suction pipe provided between the refrigerant flow switching valve and the compressor,
• the heat medium circuit including a main circuit extending from 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 heat medium circuit, an overpressure protection relief valve and a refrigerant leakage detecting device being connected, the refrigerant leakage detecting device including a pressure sensor or a pressure switch,
• in the main circuit, the overpressure protection relief valve 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 detecting device 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 controller is further configured to
• when leakage of the refrigerant into the heat medium circuit is detected, control the refrigerant flow switching valve to be switched to the second state, the expansion valve to be set to a closed state, and the compressor to start to operate or continue to operate,
• when a requirement for ending the operation of the compressor is satisfied, after the leakage of the refrigerant into the heat medium circuit is detected, control the compressor to be set to a stopped state, and the refrigerant flow switching valve to be switched to the first state, wherein the requirement for ending the operation is a requirement that one of a continuous operation time and an accumulated operation time of the compressor reaches a threshold time.

An apparatus using a heat pump, the apparatus comprising:

• a refrigerant circuit including a compressor, a refrigerant flow switching valve, a heat-source-side heat exchanger, an expansion valve, a load-side heat exchanger, and a container, the refrigerant circuit being configured to circulate refrigerant;
• a heat medium circuit and pump configured to cause a heat medium to flow via the load-side heat exchanger;
• and
• a controller;
• the refrigerant flow switching valve being configured in such a manner that a state of the refrigerant flow switching valve is switchable between a first state and a second state,
• the controller is configured to
• control the refrigerant flow switching valve to switch between the first state and the second state,
• control the refrigerant circuit to perform a first operation in which the load-side heat exchanger is used as a condenser, when the state of the refrigerant flow switching valve is switched to the first state, and
• control the refrigerant circuit to perform a second operation in which the load-side heat exchanger is used as an evaporator, when the state of the refrigerant flow switching valve is switched to the second state,
• the container being provided to a suction pipe provided between the refrigerant flow switching valve and the compressor,
• the heat medium circuit including a main circuit extending from 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 heat medium circuit, an overpressure protection relief valve and a refrigerant leakage detecting device being connected, the refrigerant leakage detecting device including a pressure sensor or a pressure switch,
• in the main circuit, the overpressure protection relief valve 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 detecting device 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 controller is further configured to
• when leakage of the refrigerant into the heat medium circuit is detected, control the refrigerant flow switching valve to be switched to the second state, the expansion valve to be set to a closed state, and the compressor to start to operate or continue to operate,
• when a requirement for ending the operation of the compressor is satisfied, after the leakage of the refrigerant into the heat medium circuit is detected, control the compressor to be set to a stopped state, and the refrigerant flow switching valve to be switched to the first state, 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.