A system includes a plurality of compressors, an evaporator, an expansion device, and a system controller. The compressors may be linked in parallel. The system controller may: determine a saturated evaporator temperature, a saturated condensing temperature, and a target capacity demand; determine an estimated system capacity and an estimated power consumption for each compressor operating configuration; compare the estimated system capacity with the target capacity demand and an error tolerance value; select an optimum operating mode based on the comparisons and based on the estimated power consumption; and command activation and deactivation of the plurality of compressors to achieve the selected optimum operating mode. The optimum operating mode may be selected after the normal system logic achieves a steady state and may be selected from a group having the estimated system capacity within the error tolerance of the target capacity demand and a lowest associated power consumption value.

The present application provides a refrigeration system using a flow of a carbon dioxide refrigerant. The refrigeration system may include a flash tank, a number of temperature suction compressors for a temperature suction cycle, and a flash gas bypass system positioned between the flash tank and the cycle compressors. The flash gas bypass system may include one or more oversized flash gas compressors so as to alternate between the temperature suction cycle and a flash tank suction cycle.

An intermediate unit includes a liquid-side pipe, a first valve, and a refrigerant pressure sensor. The liquid-side pipe is connected to a liquid connection pipe connecting a heat source unit and a utilization unit together. A controller of the intermediate unit adjusts the opening degree of the first valve based on a value measured by the refrigerant pressure sensor. The pressure of a refrigerant to be sent through the liquid connection pipe from the intermediate unit to the utilization unit is adjusted by the first valve.

A thermal management system includes a closed dynamic cooling circuit, and a closed first steady-state cooling circuit. Each circuit has its own compressor, heat rejection exchanger, and expansion device. A thermal energy storage (TES) system is configured to receive a dynamic load and thermally couple the dynamic cooling circuit and the first steady-state cooling circuit. The dynamic cooling circuit is configured to cool the TES to fully absorb thermal energy received by the TES when a dynamic thermal load is ON, and the steady-state cooling circuit is configured to cool the TES when the dynamic thermal load is OFF.

A refrigerator includes a first storage chamber, a second storage chamber spatially-separated from the first storage chamber, a first refrigeration cycle system to cool the first storage chamber using a first refrigeration cycle, and a second refrigeration cycle system installed to be separated from the first refrigeration cycle system to cool the second storage chamber using a second refrigeration cycle in an independent manner from the first refrigeration cycle. The first and second storage chambers maintain first and second target temperatures, respectively. The first and second refrigeration cycle systems circulate different kinds of refrigerants to cool the first and second storage chambers, respectively.

A refrigeration cycle device that includes a main refrigerant circuit and a sub-refrigerant circuit cools or heats a main refrigerant that flows between a main heat-source-side heat exchanger and a main usage-side heat exchanger by causing a sub-usage-side heat exchanger to function as an evaporator or a radiator of a sub-refrigerant. A first main expansion mechanism and a second main expansion mechanism that decompress the main refrigerant are provided on an upstream side and a downstream side of the sub-usage-side heat exchanger of the main refrigerant circuit.

In a refrigerant circuit of an air conditioning device, an upper heat source side heat exchanger having a large heat load and a lower heat source side heat exchanger having a small heat load are connected in parallel between an expansion device and a suction side of a compressor. Additionally, the refrigerant circuit of the air conditioning device is provided with a branch circuit configured to distribute refrigerant to each of the upper heat source side heat exchanger and the lower heat source side heat exchanger, and the branch circuit is configured to supply the upper heat source side heat exchanger with refrigerant of lower quality than that of the refrigerant supplied to the lower heat source side heat exchanger.

A system for generating steam for industrial heat. The system may include a plurality of heat pump cycles in thermal communication with each other and in thermal communication with a steam generation cycle. The plurality of heat pump cycles may include first and second heat pump cycles. The first heat pump circulates a first a working fluid and includes a first heat exchanger. The second heat pump cycle circulates a second working fluid and includes a second heat exchanger. The first heat exchanger transfers heat from the first to the second working fluid. The second heat exchanger transfers heat to a third working fluid in the steam generation cycle.

Provided is a refrigerator system with which refrigerators can be operated efficiently. This refrigerator system has: an upstream refrigerator having a first compressor that compresses a refrigerant, a first condenser that condenses the refrigerant compressed by the first compressor, and a first evaporator that evaporates the refrigerant condensed by the first condenser and cools cold water; a downstream refrigerator having a second compressor that compresses a refrigerant, a second condenser that condenses the refrigerant compressed by the second compressor, and a second evaporator that evaporates the refrigerant condensed by the second condenser and cools the cold water that has passed through the first evaporator; and a higher-level control device that controls the operation of the upstream refrigerator and the downstream refrigerator. The first compressor is a variable-speed device, and the second compressor is a constant-speed device.

A refrigerator includes a first refrigeration cycle unit that is configured to circulate a first refrigerant and that includes a first compressor, a first condenser, a first expansion device, and a first evaporator, a second refrigeration cycle unit that is configured to circulate a second refrigerant and that includes a second compressor, a second condenser, a second expansion device, and a second evaporator, a first valve unit installed at an outlet side of the first compressor, and a first hot gas path configured to extend from the first valve unit to the second evaporator and configured to supply the first refrigerant to the second evaporator.