A refrigerator includes a compressor configured to compress a refrigerant, a condenser configured to condense the refrigerant compressed in the compressor, an expander configured to depressurize the refrigerant condensed in the condenser, a plurality of evaporators configured to evaporate the refrigerant depressurized in the expander, a first valve configured to be operated to introduce the refrigerant into at least one of the plurality of evaporators, a hot gas valve device disposed at an inlet side of the first valve and configured to guide the refrigerant passed through the compressor or the condenser to the plurality of evaporators, and a hot gas path configured to extend from the hot gas valve device to the plurality of evaporators.

There is provided a HVAC system comprising: a fluid circuit for conveying a refrigerant; a compressor for compressing the refrigerant; three heat exchangers defining an evaporator, an outdoor exchanger and a heat recovery exchanger provided along the fluid circuit; an expansion valve provided along the fluid circuit; and a receiver connected in parallel to the expansion valve, wherein a fill valve is located between the receiver and a connection upstream of the expansion valve and a drain valve is located between the receiver and a connection downstream of the expansion valve; wherein the fluid circuit comprises a plurality of valves which are configured to be controlled based on a selected operating mode such that at least one of the outdoor exchanger and the heat recovery exchanger is connected to a discharge line of the compressor and in series with one of the other heat exchangers which is connected to a suction line of the compressor, with the expansion valve disposed between the heat exchangers; wherein the fill and drain valves are configured to be controlled to store a volume of refrigerant in the receiver so as to provide an effective refrigerant charge in the fluid circuit that corresponds to the selected operating mode.

There is provided a HVAC system comprising: a fluid circuit for conveying a refrigerant; a compressor for compressing the refrigerant; three heat exchangers defining an evaporator, an outdoor exchanger and a heat recovery exchanger provided along the fluid circuit; an expansion valve provided along the fluid circuit; and a receiver connected in parallel to the expansion valve, wherein a fill valve is located between the receiver and a connection upstream of the expansion valve and a drain valve is located between the receiver and a connection downstream of the expansion valve; wherein the fluid circuit comprises a plurality of valves which are configured to be controlled based on a selected operating mode such that at least one of the outdoor exchanger and the heat recovery exchanger is connected to a discharge line of the compressor and in series with one of the other heat exchangers which is connected to a suction line of the compressor, with the expansion valve disposed between the heat exchangers; wherein the fill and drain valves are configured to be controlled to store a volume of refrigerant in the receiver so as to provide an effective refrigerant charge in the fluid circuit that corresponds to the selected operating mode.

A method includes measuring a saturated suction temperature, receiving actual temperature value reflective of the measured saturated suction temperature, and determining whether the actual temperature value is less than a first pre-determined minimum threshold temperature value. If the actual temperature value is less than the first pre-determined minimum threshold temperature value, initiating a timer to operate for a pre-determined time interval. Determining whether the actual temperature value is less than a second pre-determined minimum threshold temperature value and if the actual temperature value is less the second pre-determined minimum threshold temperature value, initiating the timer to operate for a modified time interval. If the timer has expired, the operation of the compressor is modified.

A method includes measuring a saturated suction temperature, receiving actual temperature value reflective of the measured saturated suction temperature, and determining whether the actual temperature value is less than a first pre-determined minimum threshold temperature value. If the actual temperature value is less than the first pre-determined minimum threshold temperature value, initiating a timer to operate for a pre-determined time interval. Determining whether the actual temperature value is less than a second pre-determined minimum threshold temperature value and if the actual temperature value is less the second pre-determined minimum threshold temperature value, initiating the timer to operate for a modified time interval. If the timer has expired, the operation of the compressor is modified.

A method of defrosting a heat pump device including a water tank, a heat exchanger, an electrical heating element, an evaporator, a fan for the evaporator, and a control unit. In a first operating mode, the heat pump device is controlled to heat water inside the water tank. In a second operating mode, the electrical heating element is manually activated to additionally heat the water inside the water tank. In a third operating mode, the electrical heating element is automatically activating to heat the water in the storage tank if: the power supplied by the heat pump device to heat the water inside the water tank is not sufficient; if a time limit after activation of a deicing operation has lapsed; and/or if the number of times the deicing operation has been activated during a predetermined time interval exceeds a threshold value.

Systems and methods have demonstrated the capability of rapidly cooling the contents of pods containing the ingredients for food and drinks.

A heat pump system includes a compressor; an indoor heat exchanger; an outdoor heat exchanger configured as an interlaced heat exchanger having at least two refrigerant flow paths; a plurality of throttling elements; and a first type four-way valve and a second type four-way valve, with ports thereof respectively connected to the inlet and the outlet of the compressor, the indoor heat exchanger, and one of the at least two refrigerant flow paths of the outdoor heat exchanger; in a local defrosting mode, refrigerant from the outlet of the compressor flows respectively through the indoor heat exchanger and at least one of the at least two refrigerant flow paths of the outdoor heat exchanger, and then sequentially through the throttling elements, at least the other of the at least two refrigerant flow paths of the outdoor heat exchanger, and the inlet of the compressor.

An absorption chiller includes a heating medium supply pipe configured to supply a heating medium from a heating medium pipe to a cooling water pipe; a cooling water discharge pipe configured to discharge a cooling water from the cooling water pipe to the heating medium pipe; a control valve provided on the heating medium supply pipe and the cooling water discharge pipe, respectively; and a controller configured to cause the control valve to be opened and to cause the heating medium in the heating medium pipe to be introduced into the cooling water pipe, when a temperature detected by a cooling water temperature detector is equal to or lower than a predetermined temperature, in a wet lay-up state including a state in which a cooling water inlet shut-off valve and a cooling water outlet shut-off valve are closed and the cooling water pipe is filled with the cooling water.

The present disclosure provides a refrigeration device including a circuit having an evaporator, a compressor, a condenser, and an expansion valve orderly connected by a refrigerant flow path. The refrigeration device further includes a first sensor to sense ambient temperature, second sensor to sense evaporator inlet temperature, a microwave module disposed proximal to the evaporator to generate microwaves, and a controller coupled to the first sensor, the second sensor and the microwave module. The controller determines whether a difference in temperature value between the ambient temperature and the evaporator inlet temperature is equal to or greater than a first predetermined temperature value, and initiates operation of the microwave module to heat an inlet of the evaporator when the difference in temperature value between the ambient temperature and the evaporator inlet temperature is equal to or greater than the first predetermined temperature value.