A refrigerating apparatus includes a high-temperature side circuit and a low-temperature side circuit connected to each other via a cascade condenser, a low-temperature side second flow control valve that turns a refrigerant, passing through a liquid pipe connecting between a cooling unit and other circuit parts in a low-temperature side circuit b, into a gas-liquid two-phase refrigerant, and an expansion tank connected to the suction side of a low-temperature circuit compressor via a tank electromagnetic valve.

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.

Climate control systems and methods of operating them are provided that circulate a working fluid including a high glide refrigerant blend having first and second refrigerants with a difference in boiling points about 25 F. at atmospheric pressure. The system includes a gas-liquid separation vessel that generates a vapor stream and a liquid stream. A compressor receives the vapor stream and generates a pressurized vapor stream. A liquid pump receives the liquid stream and generates a pressurized liquid stream. A condenser is disposed downstream of the compressor and liquid pump and receives and cools the pressurized mixed vapor and liquid stream. An evaporator receives and at least partially vaporizes the multiphase working fluid and directs it to the gas-liquid separating vessel. An expansion device between the condenser and the evaporator processes the multiphase working fluid stream. Lastly, a fluid conduit for circulating the working fluid through the components is provided.

A refrigerator according to the present invention includes: a cooling part for cooling an object to be cooled through heat exchange with a refrigerant; an expander-integrated compressor including a compressor for compressing the refrigerant and an expander for expanding the refrigerant integrated therein; and a refrigerant circulation line configured to circulate the refrigerant through the compressor, the expander, and the cooling part. The compressor includes a low-stage compressor, a middle-stage compressor, and a high-stage compressor disposed in series in the refrigerant circulation line. The expander-integrated compressor includes: the middle-stage compressor; an expander for adiabatically expanding and cooling the refrigerant discharged from the high-stage compressor; a first motor having an output shaft connected to the middle-stage compressor and to the expander; at least one non-contact type bearing, disposed between the middle-stage compressor and the expander, for supporting the output shaft of the first motor without being in contact with the output shaft; and a casing for housing the middle-stage compressor, the expander, and the at least one non-contact type bearing.

A system for maximizing the measured efficiency of an HVAC&R system may include the steps of (1) providing a plurality of operating parameters selected from the group consisting of condenser fan speed, evaporator fan speed, inlet solenoid valve position, outlet solenoid valve position, and compressor control to the air conditioner or the heat pump system wherein each of the plurality of operating parameters has a respective operating parameter value; (2) calculating an initial efficiency of the system using signals received from a plurality of components selected from the group consisting of a temperature sensor, a humidity sensor, a pressure sensor, a flow sensor, a voltage sensor, and a current sensor; and (3) proceeding, starting with a first of the plurality of operating parameters, to iteratively adjust values of each of the plurality of operating parameters and accept the new values only if the measured efficiency increases.

A Brayton cycle type refrigerating apparatus using multiple stages of compressors and having a good response without reduction in efficiency due to change in heat load of the object to be cooled is provided. The Brayton cycle type refrigerating apparatus includes on a refrigerant line on which multiple stages of compressors are arranged in series. The apparatus also includes a temperature sensor for detecting heat load of an object to be cooled and a buffer tank provided between a low pressure line and a high pressure line. A flow rate of the refrigerant in the refrigerant line is controlled by controlling opening degrees of valves to adjust the cooling capacity.

Systems and methods for heating and cooling an interior space using a heat pump and an air duct system are provided. The heat pump system may be a split system with an indoor heat exchanger and an outdoor heat exchanger. The outdoor heat exchanger may have a volume capacity for holding a fluid such as refrigerant that is significantly larger than that of the indoor heat exchanger. In the heating cycle, the fluid may backup in the heat pump due to the difference in volume capacity between the heat exchangers. To accommodate the excess fluid, the heat pump may include a charge storage vessel. In one example, during a heating cycle, the charge storage vessel and the indoor coils may together serve as the condenser. The charge storage vessel may then prevent and/or relieve pressure build up in the compressor, which could negatively impact efficiency of the heat pump.

A decentralized condenser evaporator system includes (i) a condenser system positioned to receive a gaseous refrigerant from a centralized compressor system and configured to condense the gaseous refrigerant into a liquid refrigerant, (ii) a controlled pressure receiver positioned to receive and store the liquid refrigerant, (iii) an evaporator system including a conduit, an expansion valve, and a fan, and (iv) a controller. The conduit is positioned to receive the liquid refrigerant from the controlled pressure receiver. The expansion device is positioned between the controlled pressure receiver and the conduit, and configured to facilitate modulating an amount of the liquid refrigerant that flows into the conduit from the controlled pressure receiver. The fan is positioned to facilitate providing a cooling operation to an area associated with the evaporator system through evaporation of the liquid refrigerant flowing through the conduit. The controller is configured to control a stage of the condenser system and/or the evaporator system to maintain a desired level of the liquid refrigerant within the controlled pressure receiver and facilitate maintaining a system condensing pressure of the refrigeration system at a target system condensing pressure.

A cooling system is disclosed so that an operator cabin can be cooled even if the engine is off. An accumulator can be used to store high-pressure refrigerant until its release. When the compressor is off, the accumulator can release the high pressure refrigerant through the pressure reducer and to the evaporator where heat in the operator cabin can be removed by the refrigerant. An absorption bed with activated carbon can be used to adsorb the refrigerant from the evaporator in order to create a pressure gradient in A/C system. The refrigerant in the accumulator can also be used to subcool a refrigerant in the condenser through a heat exchanger. This allows the operator cabin to be cooled faster up on engine start up. The adsorption bed can also be used to create a pressure gradient in the cooling system.

A decentralized condenser evaporator system includes (i) a condenser system positioned to receive a gaseous refrigerant from a centralized compressor system and configured to condense the gaseous refrigerant into a liquid refrigerant, (ii) a controlled pressure receiver positioned to receive and store the liquid refrigerant, (iii) an evaporator system including a conduit, an expansion valve, and a fan, and (iv) a controller. The conduit is positioned to receive the liquid refrigerant from the controlled pressure receiver. The expansion device is positioned between the controlled pressure receiver and the conduit, and configured to facilitate modulating an amount of the liquid refrigerant that flows into the conduit from the controlled pressure receiver. The fan is positioned to facilitate providing a cooling operation to an area associated with the evaporator system through evaporation of the liquid refrigerant flowing through the conduit. The controller is configured to control a stage of the condenser system and/or the evaporator system to maintain a desired level of the liquid refrigerant within the controlled pressure receiver and facilitate maintaining a system condensing pressure of the refrigeration system at a target system condensing pressure.