A heat pump system includes a refrigerant circuit that has a compressor, a first heat exchanger, a second heat exchanger, a reheat heat exchanger, a modulating valve, and a reversing valve. The reversing valve is configured to transition between a first configuration to direct refrigerant from the compressor toward the modulating valve and a second configuration to direct the refrigerant from the compressor toward the first heat exchanger. The heat pump system also includes control circuitry configured to concurrently maintain the reversing valve in the first configuration and adjust a position of the modulating valve to direct a first portion of the refrigerant from the modulating valve to the second heat exchanger and a second portion of the refrigerant from the modulating valve to the reheat heat exchanger based on an operating mode of the heat pump system.

A heat pump may include a compressor configured to compress a refrigerant, a first temperature sensor configured to detect an outdoor temperature, a second temperature sensor provided in heating pipes connected to a heating device that performs indoor heating and configured to detect a temperature of fluid flowing through the heating pipes, an outdoor heat exchanger configured to perform heat exchange between outdoor air and a refrigerant, a third temperature sensor configured to detect a temperature of the outdoor heat exchanger, and a controller. The controller may be configured to: control power to a boiler and/or to the compressor based on sensing values of the first, second, and third temperature sensors, calculate an expected efficiency of the heat pump based on the sensing value of the first temperature sensor and an initial target temperature, and control power to the boiler based on the expected efficiency.

A refrigeration apparatus includes a compressor, a heat source-side heat exchanger, a receiver, a utilization-side heat exchange, a receiver degassing pipe interconnecting an upper portion of the receiver and a suction side of the compressor, and a receiver liquid level detection pipe connected to the receiver. The receiver liquid level detection pipe detects whether or not liquid level in the receiver has reached a predetermined position on a lower side of a position where the receiver degassing pipe is connected. The receiver liquid level detection pipe merges with the receiver degassing pipe via a capillary tube. The receiver degassing pipe has a refrigerant heater to heat refrigerant flowing through the receiver degassing pipe. Whether or not the liquid level in the receiver has reached the predetermined position is detected using a temperature of refrigerant flowing though the receiver degassing pipe.

A heat-pump system may include a compressor, an outdoor heating exchanger, an indoor heat exchanger, an expansion device, and a supplemental heater. The outdoor heat exchanger may be in fluid communication with the compressor. The indoor heat exchanger may be in fluid communication with the compressor. The expansion device may be in fluid communication with the indoor and outdoor heat exchangers. The supplemental heater may include a burner and a working-fluid conduit. The burner may be configured to burn a fuel and heat the working-fluid conduit. When the heat-pump system is operating in a heating mode, the indoor heat exchanger may receive working fluid from the working-fluid conduit such that the working fluid flows from an outlet of the working-fluid conduit to an inlet of the indoor heat exchanger.

An air conditioning system includes an air conditioning apparatus, and a controller. The air conditioning apparatus performs air conditioning of an air-conditioning target space. The controller is connectable to a plurality of types of thermostats. The controller performs communication with the thermostat connected thereto. The controller performs a performance determination process for the refrigeration cycle apparatus. The controller performs different performance determination processes according to whether a first type of thermostat is connected thereto unit or whether a second type of thermostat is connected thereto. Alternatively, the air conditioning apparatus changes a method for using information received by the controller from the thermostat according to whether being in a determination processing time over which the performance determination process is performed or in a non-determination processing time over which the performance determination process is not performed.

A heat pump may include a compressor configured to compress a refrigerant, a first temperature sensor configured to detect an outdoor temperature, a second temperature sensor provided in heating pipes connected to a heating device, and a controller. Based on a first sensing value of the first temperature sensor, the controller may be configured to control a compressor, control power to a boiler, and/or calculate an expected efficiency of the heat pump. Based on the expected efficiency and/or a second sensing value of a second temperature sensor, the controller may be configured to control power to the boiler.

A heat pump system includes a refrigerant circuit that has a compressor, a first heat exchanger, a second heat exchanger, a reheat heat exchanger, a modulating valve, and a reversing valve. The reversing valve is configured to transition between a first configuration to direct refrigerant from the compressor toward the modulating valve and a second configuration to direct the refrigerant from the compressor toward the first heat exchanger. The heat pump system also includes control circuitry configured to concurrently maintain the reversing valve in the first configuration and adjust a position of the modulating valve to direct a first portion of the refrigerant from the modulating valve to the second heat exchanger and a second portion of the refrigerant from the modulating valve to the reheat heat exchanger based on an operating mode of the heat pump system.

A refrigerant system includes a compressor configured to pressurize a refrigerant fluid. The compressor includes a sump portion. A heater is situated to heat at least the sump portion. A controller is configured to selectively operate the heater to apply heat to at least the sump portion while the compressor is off and continue operating the heater when the compressor turns on until a temperature of the compressor or a temperature of fluid discharged from the compressor satisfies at least one criterion.

An intelligent heat pump system having a dual heat exchanger structure includes a heat source side heat exchange member, a heat pump, an external expansion valve, a refrigerant-water heat exchanger, a heat storage tank, and a target side end unit. A refrigerant flows through the heat pump, the refrigerant-water heat exchanger, and the target side end unit, and in a non-air-conditioning state for the target site, circulates between the heat pump and the refrigerant-water heat exchanger, so that cooled or heated water is stored in the heat storage tank. In an air-conditioning state for the target site, the heat pump and the heat storage tank supply cooling and heating to the target site, so that the power consumption for normal operation is reduced in order to improve the operation efficiency of the intelligent heat pump system.

A heat pump may include a compressor configured to compress a refrigerant, a first temperature sensor configured to detect an outdoor temperature, a second temperature sensor provided in heating pipes connected to a heating device that performs indoor heating and configured to detect a temperature of fluid flowing through the heating pipes, an outdoor heat exchanger configured to perform heat exchange between outdoor air and a refrigerant, a third temperature sensor configured to detect a temperature of the outdoor heat exchanger, and a controller. The controller may be configured to: control power to a boiler and/or to the compressor based on sensing values of the first, second, and third temperature sensors, calculate an expected efficiency of the heat pump based on the sensing value of the first temperature sensor and an initial target temperature, and control power to the boiler based on the expected efficiency.