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 decentralized condenser evaporator system includes a condenser system, a controlled pressure receiver, a subcooler system, and an evaporator system. The condenser system is positioned to receive a compressed gaseous refrigerant from a centralized compressor system. The condenser system is configured to condense the compressed gaseous refrigerant into a liquid refrigerant. The controlled pressure receiver is positioned to receive and store the liquid refrigerant. The subcooler system is positioned to receive the liquid refrigerant from the controlled pressure receiver. The subcooler system is configured to sub-cool the liquid refrigerant into a sub-cooled liquid refrigerant. The evaporator system is positioned to receive the sub-cooled liquid refrigerant from the subcooler system. The evaporator system is configured to facilitate providing a cooling operation to a cooling zone through evaporation of the sub-cooled liquid refrigerant flowing through the evaporator system into an evaporated gaseous refrigerant which is returned to the centralized compressor system.

A method for controlling a vapor compression system during start-up is disclosed. The rate of change, ΔT.sub.1, of the temperature of refrigerant entering the evaporator, and the rate of change, ΔT.sub.2, of the temperature of refrigerant leaving the evaporator are compared. Based on the comparing step, a refrigerant filling state of the evaporator is determined. The opening degree of the expansion device is then controlled according to a first control strategy in the case that it is determined that the evaporator is full or almost full, and according to a second control strategy in the case that it is determined that the evaporator is not full. Thereby it is ensured that a maximum filling degree of the evaporator is quickly reached, without risking that liquid refrigerant passes through the evaporator.

A refrigerant recovery management system includes a first generation unit and a second generation unit. The first generation unit generates first information to send a refrigerant recovered from refrigerant-use equipment to a refrigerant treatment practitioner that conducts refrigerant treatment on the refrigerant. The second generation unit generates second information on the refrigerant treatment, to report the refrigerant treatment to a manager that manages refrigerant recovery.

An outdoor unit includes a compressor compressing a sucked refrigerant and discharging compress, an outdoor heat exchanger exchanging heat between outdoor air and the refrigerant, an accumulator storing a liquefied refrigerant at a suction side of the compressor, a solenoid valve for storing the refrigerant in the outdoor heat exchanger, and a controller performing control so as to feed the refrigerant stored within the outdoor heat exchanger during a defrosting operation, to the accumulator on the basis of an amount of refrigerant within the accumulator when operation is switched to a heating operation from the defrosting operation.

A refrigerant control system includes: a charge module configured to determine an amount of refrigerant that is present within a first portion of a refrigeration system within a building; and an isolation module configured to selectively open and close an isolation valve of the refrigeration system and to, via the isolation valve, maintain the amount of refrigerant within the first portion within the building below a predetermined amount of the refrigerant.

An air-conditioning apparatus including heat source apparatuses each including a compressor and an accumulator includes: a refrigerant amount calculation unit that calculates an amount of the refrigerant accumulated in the accumulator in one of the heat source apparatuses that is to be controlled; a refrigerant differential amount calculation unit configured to calculate, when the number of the heat source apparatuses is two, a differential amount between the calculated amount and an amount of the refrigerant in the accumulator in the other heat source apparatus, and calculate, when the number of the heat source apparatuses is three or more, a differential amount between the calculated amount of the refrigerant and an average amount of amounts of the refrigerant accumulated in the accumulators in the heat source apparatuses; and a liquid equalization control unit that controls the heat source apparatus to be controlled, based on the calculated differential amount.

A refrigeration apparatus (1) includes a heat-source-side unit (10) using a refrigerant that works in a supercritical region. The heat-source-side unit (10) includes a compression element (20) configured to compress the refrigerant, a heat-source-side heat exchanger (24), an expansion valve (26) provided downstream of the heat-source-side heat exchanger (24), a receiver (25) provided downstream of the expansion valve (26), and a control unit (101). The control unit (101) performs a first operation for evaluating the amount of the refrigerant based on a high-pressure-side pressure, on a first condition that the internal pressure of the receiver (25) be equal to or less than a supercritical pressure.

A cooling apparatus includes a heat receiver that evaporates a low pressure heat transfer medium; a compressor that compresses the evaporated heat transfer medium in a gas phase state, a condenser that condenses the compressed heat transfer medium, a receiver tank that receives and stores at least one of the heat transfer medium from any place in a flow path of the heat transfer medium in the gas phase state that returns the heat transfer medium to the heat receiver and the condensed heat transfer medium in a liquid phase state, an air storage tank that introduces and stores air separated from the heat transfer medium in the receiver tank, and a liquid level controller that controls a liquid level in the receiver tank such that the heat transfer medium in the liquid phase state is stored in the receiver tank at a predetermined liquid level height.

A refrigerant measurement adjustment system includes: a refrigerant sensor for a building and configured to measure an amount of refrigerant present in air outside of a refrigeration system of the building; and an adjustment module configured to: adjust the amount of refrigerant measured based on an adjustment to produce an adjusted amount; and determine the adjustment based on at least one of: an air temperature; an air pressure; a relative humidity of air; a mode of operation of the refrigeration system; a change in the measurements of the refrigerant sensor over time; and whether a blower that blows air across a heat exchanger of the refrigeration system located within the building is on.