A dynamic method of maintaining a predefined sub-cooling of a refrigerant exiting a condenser by dynamic control of the circulating mass of refrigerant, by transferring the refrigerant into or towards a receiver installed in parallel with the liquid connection between the condenser and the expansion valve, as a function of the difference in temperatures between the condensation temperature of the saturation liquid and the discharge temperature from the condenser.

A heat pump includes a refrigerant loop. The refrigerant loop includes a compressor, a first condenser, a vapor generator having a first region and a second region, a first expansion valve, a second expansion valve, and a first evaporator. A branching point is positioned between the first condenser and the vapor generator. The branching point diverts a portion of a first heat exchange fluid circulating through the refrigerant loop to the vapor generator. The first expansion valve is positioned between the branching point and the vapor generator. An outlet of the vapor generator is coupled to a mid-pressure inlet port of the compressor.

A heat recovery air-conditioning hot water system and a refrigerant flow control method therefor. The heat recovery air-conditioning hot water system includes a compressor, a condenser, heat exchangers, an indoor unit, a first throttling device, a second throttling device, a first reversing valve, and a second throttling device, wherein the first reversing valve is used to control the refrigerant switching of the indoor heat exchanger, so as to realize the switching of cooling and heating modes; the second reversing valve is used to control the refrigerant switching of the outdoor heat exchanger, so as to realize the operation switching of cooling and heating modes of the outdoor heat exchanger; and an exhaust pipe of the compressor is respectively connected to the first reversing valve, the second reversing valve, and the water-side heat exchanger by means of a water-side high-pressure air pipe.

A heat pump boiler is disclosed. The heat pump boiler includes a compressor. The heat pump boiler further includes an exterior heat exchanger that is configured to transfer heat between refrigerant and exterior air. The heat pump boiler further includes an interior heat exchanger that is configured to transfer heat between refrigerant and water. The heat pump boiler further includes a channel change valve that is configured to provide refrigerant compressed by the compressor to the exterior heat exchanger or the interior heat exchanger. The heat pump boiler further includes a first boiler heat exchanger that is configured to heat water that has passed through the interior heat exchanger from heat generated through combustion. The heat pump boiler further includes a second boiler heat exchanger that is configured to transfer heat between refrigerant and gas discharged from the first boiler heat exchanger.

A chiller includes an evaporator, a compressor including a prime mover, a first pressure sensor that detects a first pressure in the evaporator, a second pressure sensor that detects a second pressure in a condenser, and a controller. The controller determines a predicted energy level of the compressor based on the first pressure and the second pressure, the predicted energy level associated with liquid droplet flow into the compressor, compares the predicted energy level to an operating energy level, and modifies the at least one of the input power and the input current to the prime mover based on the comparison satisfying a modification condition.

A compressor includes a diffuser passage configured to receive refrigerant flow from an impeller of the compressor, where the diffuser passage is at least partially defined by a compressor discharge plate of the compressor. The compressor also includes a variable geometry diffuser positioned within the diffuser passage and configured to adjust a dimension of a refrigerant flow path through the diffuser passage, an actuator coupled to the variable geometry diffuser and configured to adjust a position of the variable geometry diffuser within the diffuser passage, and a controller configured to regulate operation of the actuator. The controller is configured to instruct the actuator to adjust the position of the variable geometry diffuser from a first position to a second position using a first force and to adjust the position of the variable geometry diffuser from the second position to a third position using a second force less than the first force, where the variable geometry diffuser abuts the compressor discharge plate in the third position.

A heating, ventilation, air conditioning, and refrigeration (HVAC&R) system includes a heat exchanger with a shell having a first pass configured to place a fluid in a heat exchange relationship with a first refrigerant and a second pass configured to place the fluid in a heat exchange relationship with a second refrigerant. The heat exchanger also includes a water box coupled to the shell and configured to direct the fluid from the first pass to the second pass. The HVAC&R system also includes a fluid mixing manifold disposed within the water box, where the fluid mixing manifold is configured to collect and mix a plurality of flows of the fluid from within the water box to generate a mixed fluid, and a sensor coupled to the fluid mixing manifold, where the sensor is configured to measure a parameter of the mixed fluid.

A heat pump system comprises a compressor, a first heat exchanger, a second heat exchanger, a mode switching valve, a throttling element and a reservoir, wherein the throttling element is arranged on a flow path between the first heat exchanger and the second heat exchanger; and which further comprises a mode switching flow path in which a first flow path and a second flow path are arranged, the reservoir is arranged on the second flow path and each flow path is controllably opened or closed to realize different functional modes.

Disclosed is a two-stage heating geothermal system using geothermal energy. The two-stage heating geothermal system includes a geothermal heat exchanger, a geothermal heat pump, a booster heat pump, a bypass line, and a bypass line opening and closing valve. The operating efficiency of the two-stage heating geothermal system using geothermal energy is significantly improved. Hot water supply, auxiliary heating, and the like are controlled to be completely independent of main heating.

A control device controls a heating capacity during a heating operation and a defrosting capacity during a defrosting operation. The defrosting capacity of the first refrigeration cycle unit is determined to fall within a range satisfying a first determination condition and within a range satisfying a second determination condition. The first determination condition is a condition that a sum of a load capacity of a load device when the first defrosting start condition is satisfied, and the defrosting capacity of the first refrigeration cycle unit does not exceed the heating capacity of a second refrigeration cycle unit. The second determination condition is a condition that a sum of an inter-unit defrosting interval and a defrosting period of the first refrigeration cycle unit does not exceed a shortest defrosting interval of the second refrigeration cycle unit.