A 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 first ejector to receive a first gas and increase pressure of the first gas to form the second fluid at the second pressure. The first ejector is further to provide the second fluid at the second pressure to the PX.

A refrigeration apparatus includes a primary circuit with a first expansion valve, a bypass circuit extending between branching and joining portions on the refrigerant primary circuit, a heat exchanger, a second expansion valve disposed upstream of the heat exchanger in the bypass circuit, first and second refrigerant flow rate calculating components, and a determining component. The primary circuit also includes a compressor, radiator, and evaporator. The heat exchanger includes first and second refrigerant flow paths disposed on the primary and bypass circuits, respectively, to cause heat between refrigerant flowing in the paths. The first and second refrigerant flow rate calculating components calculate first and second flow rates of refrigerant flowing through the bypass circuit based on refrigeration cycle theory and fluid theory, respectively. The determining component determines whether there is refrigerant leakage or refrigerant charge deficiency based on comparison of the first and second refrigerant flow rates.

A method for controlling an aircraft air conditioning system includes the steps of detecting an operating state of an air conditioning unit of the aircraft air conditioning system and controlling the temperature of a process air mass flow supplied to the air conditioning unit in dependence on the operating state of the air conditioning unit.

A system includes a control module and a monitor module. The control module selectively operates a component of the system in an ON state. The system receives power from an electrical grid. The monitor module selectively detects a fault event of the electrical grid in response to (i) an amount of current drawn by the component or (ii) a voltage of power received by the component. In response to detecting the fault event, the control module switches the component from the ON state to a second state, determines a first delay period according to a random process, identifies an apparent conclusion of the fault event, and in response to the apparent conclusion of the fault, waits for the first delay period before switching the component back to the ON state. The component consumes less power in the second state than in the ON state.

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. Prior art large receiver vessels may be replaced with a single or dual phase cyclonic separator also housed in the plenum of the evaporative condenser.

Provided is a temperature-adjusting fluid supply apparatus that causes a fluid for temperature adjustment to be circulated between a heat exchanger that transfers heat supplied from a refrigerant to the fluid, and an object to be adjusted for temperature that uses the heat of the fluid, the temperature-adjusting fluid supply apparatus being able to prevent the fluid from freezing. A temperature-adjusting fluid supply apparatus is provided with a heat exchanger that transfers heat supplied from a refrigerant to a fluid for temperature adjustment, a supply tube through which the fluid flows from the heat exchanger toward an object to be adjusted for temperature, a return tube through which the fluid returning from the object to be adjusted for temperature flows, a flow rate adjustable pump, a flow sensor, a flow switch, a temperature sensor, and a control part. The flow switch, in comparison with the flow sensor, is able to detect flow rate changes with coarser precision, and is less affected in detection accuracy by viscosity changes in the fluid. On the basis of the temperature of the fluid detected by the temperature sensor, the control part switches between pump control based on the detection results of the flow sensor and pump control based on the detection results of the flow switch.

The embodiments disclosed herein are directed to systems and methods to control a HVAC system based on a state of an unloader of a compressor of the HVAC system.

A method of operating a refrigeration system that receives power from an electrical grid includes selectively operating at least one component of the refrigeration system in a first state. The method includes selectively detecting a fault event of the electrical grid in response to a concurrent (i) increase in amount of current drawn by the component and (ii) decrease in voltage of power received by the component. The method includes, in response to detecting the fault event, switching the component from the first state to a second state. The component consumes less power in the second state than in the first state. The method includes determining a first delay period. The method includes identifying a conclusion of the fault event. The method includes, in response to the conclusion of the fault event, waiting for the first delay period before switching the component back to the first state.

A 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 the first fluid to the PX and provide corresponding thermal energy from the first fluid to a first corresponding environment. The system further includes a first evaporator and a second evaporator each configured to provide corresponding energy from second and third corresponding environments to portions of the first fluid output from the PX. The system further includes a first compressor configured to increase pressure of first output from the first evaporator and a second compressor configured to increase pressure of second output from the second evaporator.

A dynamic receiver is included in parallel to an expander of a heating, ventilation, air conditioning, and refrigeration (HVACR) system. The dynamic receiver allows control of the refrigerant charge of the HVACR system to respond to different operating conditions. The dynamic receiver can be filled or emptied in response to the subcooling observed in the HVACR system compared to desired subcooling for various operating modes. The flow through an expander of the HVACR system can be controlled to account for the mass flow rate through an outlet valve of the dynamic receiver when the dynamic receiver is emptied, preventing or reducing instability or effects on system parameters such as the suction superheat.