A refrigeration apparatus includes a container such as an evaporator for holding refrigerant, and a compressor for compressing refrigerant vapor. The compressed vapor is returned to the container, and stored as liquid. The liquid refrigerant is withdrawn from the container and then returned to the container via a first path through a heat exchanger for cooling a space, or a second path that does not pass through the heat exchanger. Upon returning to the container, the liquid refrigerant is at least partly evaporated due to the reduced pressure in the container caused by the operation of the compressor, and the container is cooled by the latent heat of evaporation. Thus, the container can act as a cold storage unit. The cold storage effect is increased when the refrigerant is returned to the container via the second path.

A device for refrigerating and/or liquefying a working gas comprising helium, the device comprising a looped working circuit for the working gas includes, in series, a compression station, a cold box, a heat exchange system exchanging heat between the cooled working gas and a user, the device further comprising an additional pre-cooling system comprising at least one tank of auxiliary cryogenic fluid, such as liquid nitrogen, the cold box comprising a first cooling stage of the working gas comprising a first exchanger disposed at the output of the compression station as well as a second heat exchanger and a third heat exchanger, the first heat exchanger being of the aluminum plate-fin type, the second heat exchanger being of the tube or welded plate type, characterized in that the second and third heat exchangers are connected both serially and in parallel on the working circuit downstream of the first heat exchanger.

An apparatus includes a high side heat exchanger, a flash tank, a first load, a first compressor, an auxiliary cooling system, and a first check valve. The high side heat exchanger removes heat from a refrigerant. The flash tank stores the refrigerant from the high side heat exchanger. The first load uses the refrigerant to remove heat from a space proximate the first load. The first compressor compresses the refrigerant from the first load. The auxiliary cooling system removes heat from the refrigerant stored in the flash tank during a power outage. The first check valve directs the refrigerant between the first load and the first compressor back to the flash tank when the pressure of the refrigerant between the first load and the first compressor exceeds a threshold during the power outage.

A method controls the level of liquid within an evaporator of a flooded-type chiller without level sensors. The flooded-type chiller includes at least one compressor, a condenser, an expansion valve and an evaporator. A number of sensors positioned in the system measures a number of first parameter information values. A controller calculates a number of second parameter information values based on the measured first parameter information values and further determines a virtual refrigerant level as a control signal based on the second parameter information values. Based on the determined virtual refrigerant level, the controller opens, closes or holds the expansion valve with respect to a dead zone for maintaining a pre-defined target refrigerant level so as to provide the desired refrigerant level and oil in the evaporator.

A heating, ventilation, and air conditioning (HVAC) system includes an expansion device disposed between a condenser and an evaporator of a vapor compression system and a control panel communicatively coupled to the expansion device. The control panel is configured to: determine a liquid refrigerant level set point of the condenser based on parameters of the vapor compression system, provide a first control signal to increase an opening of the expansion device in response determining that the current liquid refrigerant level in the condenser is greater than a determined liquid refrigerant level set point of the condenser, and provide a second control signal to decrease the opening of the expansion device in response to determining that the current liquid refrigerant level in the condenser is less than the determined liquid refrigerant level set point of the condenser.

A liquid chiller system utilizing a refrigerant capable of possessing a liquid state and a gas/vapor state, the refrigerant being cycled through a closed loop assembly of a compressor, a condenser, an evaporator, and an expansion valve external to the evaporator. The compressor may have a lower integrated reservoir and the evaporator may have an upper dedicated reservoir such that separate, dedicated separator or receiver vessels are not required. The condenser may be positioned above the eccentric evaporator such that liquid refrigerant flows by gravity from the condenser to the evaporator.

A liquid chiller system utilizing a refrigerant capable of possessing a liquid state and a gas/vapor state, the refrigerant being cycled through a closed loop assembly of a compressor, an eccentric condenser and an eccentric evaporator. The eccentric compressor has a lower integrated reservoir and the eccentric evaporator has an upper dedicated reservoir such that separate, dedicated separator or receiver vessels are not required. The eccentric condenser is positioned above the eccentric evaporator such that liquid refrigerant flows by gravity from the eccentric condenser to the eccentric evaporator.

A refrigeration system is provided, such as for use with chillers. The system uses a tube-side condenser, such as a microchannel condenser, along with a shell-side evaporator such as a falling film evaporator. A flash tank economizer is disposed between the condenser and the evaporator, and an inlet valve to the flash tank is controlled based upon subcooling of condensate from the condenser. The vapor exiting the flash tank may be fed via an economizer line to a system compressor. Liquid phase refrigerant combined with some gas phase refrigerant exits the flash tank and is directed through an orifice before entering the evaporator.

A liquid level indicator including a liquid level calm portion that is provided with a liquid introduction inlet that communicates with a portion below the liquid level in an oil tank and a gas vent that communicates with a portion above the liquid level; and a sight glass for observing a liquid level in the liquid level calm portion, having a liquid introduction tube provided with an extension portion that communicates with the liquid introduction inlet and extends toward the bottom portion of the oil tank, and a distal end portion that communicates with the extension portion and opens in a direction other than the downward direction below the liquid level.

An evaporator heat exchanger unit for a heating cooling module for a motor vehicle is disclosed. In one aspect, the evaporator heat exchanger unit includes at least one collector expansion tank for collecting a refrigerant and one evaporator, by which at least a part of the refrigerant can be converted into gaseous form. The evaporator heat exchanger unit also includes a housing enclosing an inner chamber, wherein in the inner chamber, the collector expansion tank, the evaporator, and a cooling medium are arranged, and wherein an expansion organ is arranged on the housing, by which the refrigerant is supplied to the evaporator.