An air-conditioning apparatus includes: a heat source-side system having an intermediate heat exchanger that causes heat exchange to be performed between a heat source-side heat medium and a use-side heat medium, causes the heat source-side heat medium to receive or transfer heat, and causes the use-side heat medium to undergo a phase change; and a use-side cycle circuit formed of pipes connecting, to one another, the intermediate heat exchanger, a pump that sucks and delivers the use-side heat medium in a liquid state, a use-side heat exchanger that heats or cools air in an air-conditioning target space due to heat exchange causing a change in phase of the use-side heat medium, and a pressure-reducing device that reduces a pressure of the use-side heat medium that passes through the use-side heat exchanger, the use-side cycle circuit causing the use-side heat medium to circulate through the use-side cycle circuit.

A refrigeration system includes a main fluid loop and a secondary fluid loop. The main fluid loop includes a compressor and a heat exchanger that circulate a first working fluid. The secondary fluid loop circulates a second working fluid. The secondary fluid loop is in thermal communication with the main fluid loop at the heat exchanger. The secondary fluid loop includes a pump, a thermal energy storage, and a coil fluid line. The secondary fluid loop includes a multi-position valve configured to move between positions that selectively fluidly connect the heat exchanger, the pump, the thermal energy storage, and the coil fluid line.

A refrigeration cycle apparatus includes a refrigerant circuit including a compressor, a condenser, a pressure reducing device, and an evaporator connected by a refrigerant pipe. A refrigerant including a refrigerant having flammability is used as refrigerant circulating in the refrigerant circuit. The evaporator and the pressure reducing device are accommodated in a unit. The evaporator is disposed in the unit in such a manner that a linear distance between a refrigerant inlet of the evaporator and a refrigerant outlet of the pressure reducing device is shorter than a linear distance between a refrigerant outlet of the evaporator and the refrigerant outlet of the pressure reducing device.

The invention relates to a refrigerant for use in a single-stage or auto cascade refrigeration system. The refrigerant comprises a mixture of gasses of at least three different hydrocarbons. The at least three different hydrocarbons include butane (C4H10), ethene (C2H4) and methane (CH4). The mixture of gasses comprises at the most 10% by weight of methane (CH4). The invention also relates to a refrigeration system with methane-containing refrigerant, to a refrigeration cabinet with methane-containing refrigerant and to use of a refrigeration cabinet with such refrigerant.

A dual reclaim coil with a smart control application is provided that allows the refrigerant inlet to the HVAC unit switch between the two sides of the condenser is aimed to use the high temperature and pressure of the condenser/gas cooler outlet while a CO.sub.2 refrigerant system is operating above critical point. This occurs in hot ambient conditions, when the need for heating in the space is not as great as in the wintertime and the available heat at the condenser/gas cooler's outlet is sufficient to satisfy the heating load. This also mitigates space overcooling, while increasing the CO.sub.2 transcritical system's efficiency by subcooling the refrigerant for applications involving dehumidification HVAC systems which often results in a phenomenon called “overcooling” during the dehumidification season.

A process for conditioning air, by means of a main circuit, the main circuit being a vapor compression circuit, wherein a first refrigerant circulates, and a secondary circuit with no compressor, wherein a non-flammable second refrigerant including a hydrofluoroolefin and/or a hydrochlorofluoroolefin circulates, the main circuit and the secondary circuit being coupled to one another; the process including a heat exchange between the surroundings and the first refrigerant, a heat exchange between the first and second refrigerants, and a heat exchange between the second refrigerant and the air to be conditioned. Also, an air conditioning plant for implementing the process.

A refrigerant cycle apparatus, that circulates a flammable refrigerant in a refrigerant circuit, includes: a gas-side cutoff valve; a liquid-side cutoff valve, where the gas-side cutoff valve and the liquid-side cutoff valve are disposed on opposite sides of a first portion of the refrigerant circuit; a detection unit that detects refrigerant leakage from the first portion into a predetermined space; and a control unit that sets a cutoff state in the gas-side cutoff valve and the liquid-side cutoff valve when the detection unit detects the refrigerant leakage from the first portion into the predetermined space. The cutoff leakage rate at the gas-side cutoff valve is higher than the cutoff leakage rate at the liquid-side cutoff valve.

A method for diluting a leaked refrigerant in a refrigeration system according to an example of the present disclosure includes operating the refrigeration system in a purge mode based on at least one purge condition prior to initiating a compressor of the refrigeration system. A refrigeration system according to an example of the present disclosure includes a compressor configured to compress refrigerant in a refrigerant line, a heat exchanger configured to exchange heat with the refrigerant line in a heat exchange mode, a fan configured to pass air through the heat exchanger to an indoor space, and a controller configured to operate the refrigeration system in a purge mode based on at least one purge condition prior to initiating the compressor.

A non-azeotropic mixed refrigerant and a refrigerating apparatus using a non-azeotropic mixed refrigerant are provided. The non-azeotropic mixed refrigerant may include isobutane and propane. The non-azeotropic mixed refrigerant may be provided in a weight ratio of 50%≤isobutane≤90%. Therefore, high efficiency may be obtained in a refrigerating system using the non-azeotropic mixed refrigerant.

One or more example embodiments provide a vending machine (105) that detects refrigerant leaks. The vending machine includes a main cabinet (605), a sensor circuit (615), and control equipment (830). The sensor circuit is configured to detect a refrigerant leaked in the main cabinet. The control equipment is configured to operate a component (620) of the refrigerated vending machine based on the detected refrigerant.