The present invention relates to a heat pump system for a vehicle which can enhance heating performance of a plug-in hybrid vehicle by heating engine coolant necessary for heating using a refrigerant cycle. The heat pump system for a vehicle includes: an evaporator disposed inside an air-conditioning case to exchange heat between air and refrigerant; a heater core disposed inside the air-conditioning case to exchange heat between air and coolant; a first coolant line connecting an engine with the heater core so that the coolant is circulated; a first refrigerant circulation loop which circulates a compressor for compressing and discharging the refrigerant, an air-cooled condenser for exchanging heat between the refrigerant and air, a first expansion means for expanding the refrigerant, and the evaporator in a cooling mode; and a second refrigerant circulation loop which circulates the compressor, a water-cooled heat exchanger for exchanging heat between the refrigerant and the coolant, a second expansion means for expanding the refrigerant, and the air-cooled condenser in a heating mode. The water-cooled heat exchanger is disposed in the first coolant line between the engine and the heater core to exchange heat between the refrigerant of high temperature and high pressure passing through the compressor and the coolant of the first coolant line.

A system comprising a compressor, a first valve coupled to the compressor and coupled to a first coil, a first expansion valve coupled to the first coil, a second coil, and a second expansion valve. The second expansion valve coupled to a third coil, a second valve coupled to the compressor and the third coil. A controller operable to operate the first valve, the first expansion valve, the second expansion valve, and the second valve. The second coil is coupled to the compressor and the refrigerant flows from the second coil to the compressor.

A system comprising a compressor, a first valve coupled to the compressor and coupled to a first coil, a first expansion valve coupled to the first coil, a second coil, and a second expansion valve. The second expansion valve coupled to a third coil, a second valve coupled to the compressor and the third coil. A controller operable to operate the first valve, the first expansion valve, the second expansion valve, and the second valve. The second coil is coupled to the compressor and the refrigerant flows from the second coil to the compressor.

A vapor compression refrigeration system has a main refrigerant circuit having a primary compressor group, a gas cooler or condenser, an expansion device, a liquid receiver, and at least one evaporator. An emergency circulation duct fluidically connects the liquid receiver to the main circuit to allow a flow of refrigerant from the liquid receiver to the gas cooler. An emergency compressor group in the emergency circulation duct is activatable when pressure inside the liquid receiver or in the duct upstream of the emergency compressor group meets or exceeds a predefined emergency pressure threshold. An uninterruptible power supply powers the emergency compressor group and expansion device during a shutdown of the refrigeration system. When pressure inside the liquid receiver or in the duct upstream of the emergency compressor group equals or exceeds the predefined emergency pressure threshold, an emergency circulation of refrigerant fluid is activated through the emergency circulation duct.

A vapor compression refrigeration system has a main refrigerant circuit having a primary compressor group, a gas cooler or condenser, an expansion device, a liquid receiver, and at least one evaporator. An emergency circulation duct fluidically connects the liquid receiver to the main circuit to allow a flow of refrigerant from the liquid receiver to the gas cooler. An emergency compressor group in the emergency circulation duct is activatable when pressure inside the liquid receiver or in the duct upstream of the emergency compressor group meets or exceeds a predefined emergency pressure threshold. An uninterruptible power supply powers the emergency compressor group and expansion device during a shutdown of the refrigeration system. When pressure inside the liquid receiver or in the duct upstream of the emergency compressor group equals or exceeds the predefined emergency pressure threshold, an emergency circulation of refrigerant fluid is activated through the emergency circulation duct.

Various embodiments of a multi-evaporator sealed vapor compression system for an appliance are provided. In one example aspect, a sealed system charged with a refrigerant fluid includes a single compressor and a first and second evaporator fluidly coupled in series. A flash tank is positioned between the evaporators. One or more valves are fluidly coupled with and positioned downstream of the flash tank and the second evaporator. The valves are operable to selectively switch the flow of refrigerant fluid between the two evaporators at a frequency such that the temperature rise in the evaporators is negligible. In another aspect, a sealed system charged with a refrigerant fluid includes a single compressor and a first and second evaporator fluidly coupled in parallel. One or more valves positioned upstream of the evaporators and one or more valves are positioned downstream of the evaporators for controlling the refrigerant flow through the sealed system.

A refrigeration device has a first storage chamber, a second storage chamber and a refrigerant circuit, in which a first controllable throttle point, a first heat exchanger for controlling the temperature of the first storage chamber, a second controllable throttle point and a second heat exchanger for cooling the second storage chamber are connected in series between a pressure connection and a suction connection. A hot line section, located upstream of the second heat exchanger, and a cold line section, located downstream of the second heat exchanger, are routed in thermal contact with respect to one another in order to form an internal heat exchanger. The first heat exchanger is connected to the pressure connection bypassing the hot line section.

A refrigeration device has a first storage chamber, a second storage chamber and a refrigerant circuit, in which a first controllable throttle point, a first heat exchanger for controlling the temperature of the first storage chamber, a second controllable throttle point and a second heat exchanger for cooling the second storage chamber are connected in series between a pressure connection and a suction connection. A hot line section, located upstream of the second heat exchanger, and a cold line section, located downstream of the second heat exchanger, are routed in thermal contact with respect to one another in order to form an internal heat exchanger. The first heat exchanger is connected to the pressure connection bypassing the hot line section.

A cooling system is provided that partially floods one of its freezers (e.g., the ice cream freezer) such that the refrigerant discharged by the freezer includes a liquid component. In this manner, the freezers in the system can operate at the same saturated suction temperature. A heat exchanger can be used to transfer heat to the liquid component of the discharge to evaporate the liquid component.

A cooling system is provided that partially floods one of its freezers (e.g., the ice cream freezer) such that the refrigerant discharged by the freezer includes a liquid component. In this manner, the freezers in the system can operate at the same saturated suction temperature. A heat exchanger can be used to transfer heat to the liquid component of the discharge to evaporate the liquid component.