A passive heat recovery or defrosting apparatus features an evaporator, a condenser, and vapour and liquid conveyance lines connected therebetween. The vapour and liquid conveyance lines respectively connect to upper and lower ends of the evaporator and condenser. The evaporator and/or condenser has a ring-shaped body for fitting around or inline with a pipe to achieve heat exchange relation with a fluid passing therethrough. The evaporator is installed on or inside a warm pipe or duct (e.g. waste drain pipe, clothes dryer exhaust duct, flue pipe, or indoor section of a sewer vent stack) at a lower elevation than the condenser. The condenser is placed on an outdoor end of either a sewer stack or air intake duct for defrosting purposes, or is placed on a water supply line or air intake of a hot water tank, clothes dryer, etc. Working fluid circulates passively between the evaporator and condenser.

Systems and methods have demonstrated the capability of rapidly cooling the contents of pods containing the ingredients for food and drinks.

Systems and methods have demonstrated the capability of rapidly cooling the contents of pods containing the ingredients for food and drinks.

A control system and method for a frostless, multivariable coupling and heat pump-based hot blast stove are used for grain drying. A first heat exchanger, a second heat exchanger, a main solution pool, corresponding pipelines, and a temperature detector are configured in the control system. A first heat pump unit, a second heat pump unit and a third heat pump unit are formed. A preheating zone, a low temperature zone, a medium temperature zone and a high temperature zone are sequentially formed on an air supply pipeline from a fresh air inlet to a fresh air outlet. A frostless operation procedure is provided. Through the configuration, the control system and method for a frostless, multivariable coupling and heat pump-based hot blast stove can implement heat supply in a gradient heat-circulation preheating mode and a gradient heat-circulation frostless mode.

A refrigeration system includes a first compressor system, a second compressor system, a first conduit, a heat exchanger, a second conduit, and a third conduit. The first compressor system includes a plurality of first compressors. The second compressor system includes a plurality of second compressors. The first conduit is configured to provide refrigerant from the first compressor system to the second compressor system. The second conduit is fluidly coupled to the first conduit and configured to provide the refrigerant from the first compressor system to the heat exchanger. The third conduit is configured to provide the refrigerant from the second compressor system to the heat exchanger.

The present disclosure relates to a HVAC system operable to use a refrigerant in a refrigerant circuit to heat or cool an indoor space and includes a defrost circuit connected to the refrigerant circuit. The defrost circuit includes a first three-way valve, a defrost line, a defrost passage in an outdoor heat exchanger, and a defrost return line. When the HVAC system is in a defrost mode, a four-way valve is operable to direct the refrigerant flow in a second direction through the outdoor heat exchanger. The first three-way valve is operable to divert some or all of the refrigerant from the refrigerant circuit and through the defrost circuit to defrost the outdoor heat exchanger. The defrost return line returns the diverted refrigerant to the refrigerant circuit upstream of an expansion device and downstream of the indoor heat exchange with respect to the second direction.

An apparatus includes a high side heat exchanger, a flash tank, a subcooler, an expansion valve, a load, and a compressor. The high side heat exchanger removes heat from a refrigerant. The flash tank stores the refrigerant. The subcooler heat exchanger receives the refrigerant. During a first mode of operation, the load uses the refrigerant to cool a space proximate the load and the compressor compresses the refrigerant. During a second mode of operation, the subcooler heat exchanger directs the refrigerant to the expansion valve, transfers heat from the refrigerant from the flash tank to the refrigerant from the expansion valve and directs the refrigerant from the expansion valve to the compressor. During the second mode of operation, the compressor compresses the refrigerant from the subcooler heat exchanger and directs the compressed refrigerant from the subcooler heat exchanger to the load to defrost the first load.

An absorption heat pump having a generator, a heat source to heat the generator to drive coolant vapor out of solution, a condenser for cooling the coolant vapor and an expansion valve that expand the coolant fluid as well as an evaporator for at least partial evaporation of the expanded coolant fluid against a medium which is connected to at least one absorber which absorbs the expanded coolant fluid. A hot gas line which branches off from a line for coolant vapor upstream of the condenser and is fluid-connected to the evaporator such that it bypasses the condenser and the expansion valve, a defrosting valve being provided in the hot gas line, by means of which the flow of coolant vapor through the hot gas line can be controlled. The absorption heat pump is operated in a cyclic circulation process.

A refrigeration system includes a first compressor system, a second compressor system, a first conduit, a heat exchanger, a second conduit, and a third conduit. The first compressor system includes a plurality of first compressors. The second compressor system includes a plurality of second compressors. The first conduit is configured to provide refrigerant from the first compressor system to the second compressor system. The second conduit is fluidly coupled to the first conduit and configured to provide the refrigerant from the first compressor system to the heat exchanger. The third conduit is configured to provide the refrigerant from the second compressor system to the heat exchanger.

Systems and methods have demonstrated the capability of rapidly cooling the contents of pods containing the ingredients for food and drinks.