A predictive HVAC control apparatus and method, the predictive HVAC control apparatus having an input/output interface connected to a gain amplifier and a thermocouple amplifier, the gain amplifier connected to a first plurality of sensors disposed on an HVAC system, the HVAC system having HVAC system controls, and the temperature amplifier connected to a second plurality of sensors disposed on an HVAC system, a central processing unit connected to the input/output interface, and an HVAC control relay, connected to the input/output interface and the HVAC system controls.

An air conditioning apparatus includes: a supercooling heat exchanger configured to supercool refrigerant flowing in a first flow path between an outdoor heat exchanger and an expansion valve; a flow path switching valve configured to switch a flow path between an indoor heat exchanger and a compressor to one of a second flow path that does not extend through the supercooling heat exchanger and a third flow path that extends through the supercooling heat exchanger; a bypass circuit that is branched from the first flow path and extends through the supercooling heat exchanger; and a bypass regulating valve provided in the bypass circuit; and a controller. In a cooling operation, when a load is not low, the controller selects the second flow path and opens the bypass regulating valve, whereas when the load is low, the controller selects the third flow path and closes the bypass regulating valve.

A refrigeration system includes a gas cooler/condenser configured to remove heat from a refrigerant, a temperature sensor configured to measure a temperature of the refrigerant leaving the gas cooler/condenser, a pressure sensor located along the high pressure conduit and configured to measure a pressure of the refrigerant leaving the gas cooler/condenser, a pressure control valve operable to regulate the pressure of the refrigerant leaving the gas cooler/condenser, and a controller. The controller is configured to determine whether the refrigerant leaving the gas cooler/condenser is in a subcritical region based on at least one of the measured temperature of the refrigerant or the measured pressure of the refrigerant. If the refrigerant leaving the gas cooler/condenser is not in the subcritical region, the controller is configured to add a pseudo-subcooling temperature value to the measured temperature of the refrigerant to calculate a summed temperature, calculate a supercritical pseudo-saturated pressure as a function of the summed temperature, and operate the pressure control valve to drive the pressure of the refrigerant leaving the gas cooler/condenser to the supercritical pseudo-saturated pressure corresponding to the summed temperature.

A controller of a heating, ventilation, and air conditioning (HVAC) system, the controller comprising instructions that cause the controller to determine an air flowrate of an air blower of the HVAC system and calculate a threshold value based on a minimum required air flowrate. The controller further comprises instructions that cause the controller to send a notification to an operator of the HVAC system indicating that the air flowrate of the air blower is less than the threshold value in response to determining that the air flowrate of the air blower is less than the threshold value and shut down the HVAC system such that the refrigerant is no longer circulated by the componentry of the HVAC system in response to determining that the air flowrate of the air blower is less than the minimum required air flowrate.

A refrigeration system includes a gas cooler/condenser configured to remove heat from a refrigerant, a temperature sensor configured to measure a temperature of the refrigerant leaving the gas cooler/condenser, a pressure sensor located along the high pressure conduit and configured to measure a pressure of the refrigerant leaving the gas cooler/condenser, a pressure control valve operable to regulate the pressure of the refrigerant leaving the gas cooler/condenser, and a controller. The controller is configured to determine whether the refrigerant leaving the gas cooler/condenser is in a subcritical region based on at least one of the measured temperature of the refrigerant or the measured pressure of the refrigerant. If the refrigerant leaving the gas cooler/condenser is not in the subcritical region, the controller is configured to add a pseudo-subcooling temperature value to the measured temperature of the refrigerant to calculate a summed temperature, calculate a supercritical pseudo-saturated pressure as a function of the summed temperature, and operate the pressure control valve to drive the pressure of the refrigerant leaving the gas cooler/condenser to the supercritical pseudo-saturated pressure corresponding to the summed temperature.

A system includes a pressure exchanger (PX) configured to receive a first fluid at a first pressure, receive a second fluid at a second pressure, and exchange pressure between the first fluid and the second fluid. The first fluid is to exit the PX at a third pressure and the second fluid is to exit the PX at a fourth pressure. The system further includes a condenser configured to receive the first fluid from a compressor and provide corresponding thermal energy from the first fluid to a first environment. The system further includes a heat exchanger configured to receive the first fluid output from the condenser.

A packaged, pumped liquid, evaporative-condensing recirculating ammonia refrigeration system with charges of 10 lbs or less of refrigerant per ton of refrigeration capacity. The compressor and related components are situated inside the plenum of a standard evaporative condenser unit, and the evaporator is close coupled to the evaporative condenser. Single or dual phase cyclonic separators may also be housed in the plenum of the evaporative condenser.

A dual reclaim coil with a smart control application is provided that allows the refrigerant inlet to the HVAC unit switch between the two sides of the condenser is aimed to use the high temperature and pressure of the condenser/gas cooler outlet while a CO.sub.2 refrigerant system is operating above critical point. This occurs in hot ambient conditions, when the need for heating in the space is not as great as in the wintertime and the available heat at the condenser/gas cooler's outlet is sufficient to satisfy the heating load. This also mitigates space overcooling, while increasing the CO.sub.2 transcritical system's efficiency by subcooling the refrigerant for applications involving dehumidification HVAC systems which often results in a phenomenon called overcooling during the dehumidification season.

A fluid handling system includes a pressure exchanger (PX) configured to receive a first fluid at a first pressure and a second fluid at a second pressure and exchange pressure between the first fluid and the second fluid. The system further includes a condenser configured to provide corresponding thermal energy from the first fluid to a corresponding environment. The system further includes a receiver to receive the first fluid output by the PX. The receiver forms a chamber to separate the first fluid into a first gas and a first liquid. The system further includes a first booster to increase pressure of a portion of the first gas to form the second fluid at the second pressure and provide the second fluid at the second pressure to the PX.

A multi-connection air conditioning system and a method for calculating a heat exchange amount thereof includes a plurality of indoor units, and the method includes: obtaining a total heat exchange amount of the multi-connection air conditioning system; obtaining inlet air temperature of each indoor unit; obtaining a two-phase saturation temperature of each indoor unit; obtaining an air supply volume of each indoor unit; obtaining a heat exchange area of each indoor unit; and calculating a heat exchange amount of each indoor unit according to the total heat exchange amount of the multi-connection air conditioning system, the inlet air temperature of each indoor unit, the two-phase saturation temperature of each indoor unit, the air supply volume of each indoor unit, and the heat exchange area of each indoor unit. Thus the user can monitor the heat exchange amount of each indoor unit so that they can be managed with separate targets.