Efficiency in refrigerant charging work is addressed when a recovered refrigerant recovered from a first heat source unit is to be charged to a second heat source unit. A refrigerant charging method is a charging method used when a first heat source unit of an already installed refrigeration cycle apparatus in which a refrigeration cycle is to be performed by a refrigerant that circulates is to be replaced with a second heat source unit. The refrigerant charging method includes recovering a first refrigerant from an already installed refrigeration cycle apparatus and obtaining a recovered refrigerant and charging the recovered refrigerant and charging a second refrigerant whose composition differs from the composition of the recovered refrigerant to the refrigeration cycle apparatus after renewal that includes the second heat source unit.

Efficiency in refrigerant charging work is addressed when a refrigerant recovered from the first heat source unit is to be charged to a second heat source unit. In a refrigerant charging method in which a first heat source unit of an already installed refrigeration cycle apparatus in which a refrigeration cycle is to be performed by a refrigerant that circulates is replaced with a second heat source unit, transferring the refrigerant from the first heat source unit to the second heat source unit is included. In addition, the method includes measuring the weight of the refrigerant that is transferred from the first heat source unit to the second heat source unit.

A heat pump device comprises a refrigerant circuit in which a compressor, a first indoor heat exchanger, an electric expansion valve, and a heat source-side heat exchanger are connected in a loop, a second indoor heat exchanger arranged between the compressor and the electric expansion valve and configured to store refrigerant during positive cycle defrost operation, an electromagnetic valve arranged between the second indoor heat exchanger and the electric expansion valve and configured to adjust an amount of refrigerant stored in the second indoor heat exchanger during the positive cycle defrost operation, and a control device that controls the compressor and the electric expansion valve.

A thermal management system includes a closed-circuit refrigeration system that includes a vapor cycle system (VCS) and a liquid pumping system (LPS). The VCS includes a receiver that stores a refrigerant fluid and a liquid separator. The vapor cycle system is configured to operate in one or more operational modes including at least one of a TES cooling mode, a heat load cooling mode, or a pump-down mode. The LPS includes a thermal energy storage (TES) that stores a phase change material (PCM) and a pump fluidly coupled to at least one evaporator. The evaporator is configured to extract heat from a heat load that is in thermal conductive or convective contact to the evaporator to transfer heat to the refrigerant fluid and provide the refrigerant fluid from an evaporator outlet to the TES.

A heat pump apparatus includes a refrigerant circuit and a heat medium circuit. The refrigerant circuit performs a first operation using a load-side heat exchanger as a condenser, and a second operation using the load-side heat exchanger as an evaporator. A suction pipe provided between a refrigerant flow switching valve and a compressor has a container. To the heat medium circuit, an overpressure protection relief valve and a refrigerant leakage detector are connected. When leakage of refrigerant into the heat medium circuit is detected, the refrigerant flow switching valve is switched to a second state, an expansion device is set to a closed state, and the compressor is operated. When a requirement for ending the operation of the compressor is satisfied after the leakage is detected, the compressor is stopped, and the refrigerant flow switching valve is switched to a first state.

A refrigerant control system includes: a reversing valve including: a first inlet configured to receive refrigerant output from a condenser; a first outlet configured to output refrigerant to an inlet of an evaporator located inside of a building; a second inlet configured to receive refrigerant output from the evaporator; and a second outlet configured to output refrigerant to an inlet of a compressor that pumps refrigerant to the condenser; a reversing module configured to: selectively actuate the reversing valve to a first position such that: refrigerant flows directly from the second inlet to the second outlet; and refrigerant flows directly from the first inlet to the first outlet; and selectively actuate the reversing valve to a second position such that: refrigerant flows directly from the second inlet to the first outlet; and refrigerant flows directly from the first inlet to the second outlet.

A refrigerant control system includes: a charge module configured to determine an amount of refrigerant that is present within a first portion of a refrigeration system within a building; and an isolation module configured to selectively open and close an isolation valve of the refrigeration system and to, via the isolation valve, maintain the amount of refrigerant within the first portion within the building below a predetermined amount of the refrigerant.

A thermal management system includes a closed-circuit refrigeration system (CCRS) that includes a vapor cycle system (VCS). The VCS includes a receiver configured to store a refrigerant fluid; a liquid separator; a compressor; a condenser; at least one evaporator configured to extract heat from at least one heat load that is in thermal conductive or convective contact with the evaporator; and a thermal energy storage (TES) that stores a phase change material. The thermal management system further includes a liquid pumping system (LPS) that includes the TES, the at least one evaporator, and the liquid separator, with the LPS further including a pump. The VCS is configured to operate one at a time in at least one of three operational modes that are a TES cooling mode, a heat load cooling mode, or a pump-down mode. The LPS is configured to operate in the heat load cooling mode.

A device for controlling the temperature of an external fluid. The device including a compressor for compressing an internal fluid, a first heat exchanger in a temperature control circuit for transferring thermal energy between the internal fluid and the external fluid. The device is further configured for use within a system for controlling the temperature of blood.

A refrigerant control system includes: a charge module configured to determine an amount of refrigerant that is present within a refrigeration system of a building; a leak module configured to diagnose that a leak is present in the refrigeration system based on the amount of refrigerant; and at least one module configured to take at least one remedial action in response to the diagnosis that the leak is present in the refrigeration system.