A method for operating a refrigeration system for a motor vehicle. The method includes setting an operating mode of the refrigeration system having active primary line and inactive secondary line or having active secondary line and inactive primary line; detecting the pressure in the inactive line; and activating and extraction of refrigerant from the inactive line into the active line by lowering the pressure in the active line to a value below the pressure in the inactive line and by opening the relevant valve device.

A transport refrigeration system includes a compressor, a heat rejection heat exchanger, a flash tank, an expansion device and a heat absorption heat exchanger arranged in a serial refrigerant flow order to circulate a refrigerant; a controller configured to: determine a presence of at least one condition of the transport refrigeration system; and initiate a low refrigerant charge detection process in response to detecting the presence of the at least one condition of the transport refrigeration system.

A refrigeration apparatus includes: a refrigerant circuit through which refrigerant circulates; a controller to execute a plurality of refrigerant shortage sensing functions of sensing a shortage of an amount of the refrigerant; and an input device through which an operation mode to be set is input into the controller. The operation mode includes: a first mode in which energy-saving performance is emphasized; and a second mode in which the refrigeration apparatus is permitted to operate in a range in which reliability is ensured. In accordance with the operation mode set through the input device, the controller determines which one of sensing results obtained by the refrigerant shortage sensing functions is enabled and which one of sensing results obtained by the refrigerant shortage sensing functions is disabled. When a sensing result determined to be enabled shows a refrigerant shortage, the controller gives a notification about the refrigerant shortage.

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.

The present disclosure relates to a heat pump and a control method thereof, and to a heat pump including an outdoor unit including a compressor for compressing a first refrigerant, a first outdoor heat exchanger for exchanging heat between the first refrigerant and outdoor air, an expansion mechanism for expanding the first refrigerant, and a second outdoor heat exchanger for exchanging heat between the first refrigerant and a second refrigerant; a first refrigerant pipe which connects the compressor, the first outdoor heat exchanger, and the expansion mechanism, and through which the first refrigerant flows; a pressure sensor disposed in the first refrigerant pipe; a second refrigerant pipe which is connected to the second outdoor heat exchanger, and through which the second refrigerant flows; an indoor heat exchanger which is disposed in the second refrigerant pipe, and exchanges heat between indoor air and the second refrigerant; and a controller configured to determine a supply of the second refrigerant by determining a flow rate of the second refrigerant based on surging occurred in a pressure of the first refrigerant measured by the pressure sensor, so that the flow rate of the second refrigerant flowing through the second refrigerant pipe is determined only by the pressure value of the first refrigerant measured by the pressure sensor disposed in the first pipe, thereby determining the flow rate of the second refrigerant without a separate flow sensor, and a control method thereof.

A refrigeration cycle apparatus is a refrigeration cycle apparatus having a refrigerant circuit having a compressor, a condenser, a supercooler, an expansion device, and an evaporator connected by a refrigerant pipe, and configured to circulate refrigerant containing refrigerant having a temperature gradient, wherein the supercooler sets a degree of supercooling of the refrigerant, which is a temperature difference between a temperature from the condenser to a refrigerant flow inlet of the supercooler and a temperature in a refrigerant flow outlet on a downstream side of the supercooler, to be larger than the temperature gradient generated at a time of refrigerant shortage of the refrigerant between the refrigerant flow inlet and the refrigerant flow outlet of the supercooler, the refrigeration cycle apparatus including a refrigerant amount determination unit configured to compare a determination threshold value set to a value larger than the temperature gradient of the refrigerant with the degree of supercooling of the refrigerant, and determine whether or not there is a shortage of a refrigerant amount filled in the refrigerant circuit.

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.

A method for estimating refrigerant charge for an HVACR system is provided. The method includes obtaining one or more system parameters during operation. The one or more system parameters include at least one of compressor suction superheat, system mass flow, expansion device mass flow or opening degree, compressor suction saturated temperature, and compressor discharge saturated temperature. The method also includes conducting a regression analysis on the one or more system parameters to determine one or more predictive parameters for estimating the refrigerant charge. The method further includes determining a predictive model based on regression analysis. The predictive model establishes a relationship between the refrigerant charge and the one or more predictive parameters. Also the method includes estimating the refrigerant charge based on the predictive model.

A refrigerant control system includes: a charge module configured to determine an amount of refrigerant that is present within a refrigeration system of a building; a leak module configured to diagnose that a leak is present in the refrigeration system based on the amount of refrigerant; and at least one module configured to take at least one remedial action in response to the diagnosis that the leak is present in the refrigeration system.

A method for estimating refrigerant charge for an HVACR system is provided. The method includes obtaining one or more system parameters during operation. The one or more system parameters include at least one of compressor suction superheat, system mass flow, expansion device mass flow or opening degree, compressor suction saturated temperature, and compressor discharge saturated temperature. The method also includes conducting a regression analysis on the one or more system parameters to determine one or more predictive parameters for estimating the refrigerant charge. The method further includes determining a predictive model based on regression analysis. The predictive model establishes a relationship between the refrigerant charge and the one or more predictive parameters. Also the method includes estimating the refrigerant charge based on the predictive model.