A gas engine heat pump and a method of operating the same are provided. According to an embodiment of the present disclosure, the gas engine heat pump includes: an engine for burning a mixture of air and fuel; an exhaust gas compressor for compressing exhaust gases coming from the engine; a buffer tank for storing the exhaust gases compressed by the exhaust gas compressor; an exhaust gas valve disposed between the buffer tank and an intake manifold of the engine; an exhaust gas spray nozzle for spraying the exhaust gases stored in the buffer tank into a cylinder of the engine; an exhaust gas sensor for acquiring information on the exhaust gases coming from the engine; and a controller, wherein the controller controls the operation of at least one of the exhaust gas valve and the exhaust gas spray nozzle, based on the information on the exhaust gases acquired by the exhaust gas sensor. Other various embodiments are possible.

A gas engine heat pump is provided including an engine having an ignition plug, a compressor connected to the engine, a mixer that mixes air and fuel and supplies the mixture to the engine, a zero governor having a valve that regulates the fuel supplied to the mixer, a throttle valve disposed between the mixer and the engine to regulate a flow of the mixture to the engine, and a controller. Upon receiving a command to stop running the engine, the controller changes a target number of revolutions of the engine, controls an opening degree of the valve based on the target number of revolutions if a current number of revolutions of the engine exceeds a first reference number, and controls the ignition plug to stop igniting if the current number of revolutions of the engine reaches a second reference number which is lower than the first reference number.

A gas heat pump system including an outdoor unit having a compressor, an outdoor heat exchanger, and an expansion device; an indoor unit having an indoor heat exchanger; a refrigerant pipe to connect the outdoor unit and the indoor unit; an engine to combust mixed fuel in which fuel and air are mixed; a coolant tank to store a coolant; a radiator to emit, to an outside, heat which is transferred from the engine to the coolant; and a coolant pipe to connect the coolant tank and the radiator to allow the coolant to circulate therethrough, whereby the gas heat pump system has a cooling capability between 71 kW and 85 kW, the refrigerant is a mixed refrigerant having at least 50% R32, and the refrigerant pipe is a ductile stainless steel pipe having a delta ferrite matrix structure of 1% or less based on grain area.

Embodiments of the present invention reduce the amount of energy required to operate air-conditioners and refrigerators by providing a vapor-compression system that harnesses a low- or no-cost source of energy, namely, heat, and uses the harnessed heat to power a new kind of compressor, called a “burst compressor” and a new kind of pump, called a “vapor pump.” The heat-driven burst compressor pressurizes the refrigerant, while also providing “push and pull” vapor refrigerant to the vapor pump. The vapor pump, actuated by the high pressure refrigerant in gaseous form provided by the burst compressor, is configured to pump a combination of gaseous, vaporous and liquid refrigerant out of the receiver tank and inject that low pressure refrigerant mix into the burst compressor, where it is heated to change the state of the refrigerant to a heated, pressurized gas. Then the heated, pressurized gas is released in bursts into the other components of the vapor compression cycle. Thus, embodiments of the present invention use heat to provide cold. Because of this arrangement, vapor-compression systems constructed and arranged to operate according to embodiments of the present invention are able to provide air-conditioning and/or refrigeration much more efficiently and with much less expense than traditional vapor compression systems for air-conditioning and refrigeration.

A refrigeration unit includes an evaporator circulating a flow of refrigerant therethrough to cool a flow of compartment air flowing over the evaporator, a compressor in fluid communication with the evaporator to compress the flow of refrigerant, an engine operably connected to the compressor to drive operation of the compressor, an expansion device in fluid communication with the flow of refrigerant, and a controller operably connected to at least the engine and the expansion device. The controller is configured to determine an available power to drive the compressor, determine a compressor discharge pressure upper limit based on the available power, compare the compressor discharge pressure upper limit to a requested compressor discharge pressure, and initiate adjustment of the expansion device such that an actual compressor discharge pressure is the lesser of the requested compressor discharge pressure or the compressor discharge pressure upper limit.

A transport refrigeration system having a refrigeration unit including: a refrigeration circuit (23) configured to circulate a first refrigerant; a mechanical subcooler (23a); and a battery system (190) configured to power the mechanical subcooler. The mechanical subcooler is thermally connected to the refrigeration circuit.

A trailer refrigeration unit is provided. Aspects include a plurality of power sources, wherein the plurality power sources are selectively coupled to a power converter and at least one compressor. The power converter is coupled to at least one fan and is selectively coupled to the at least one compressor. A microcontroller circuit is included and is configured to selectively operate the trailer refrigeration unit in one of a plurality of modes based on an environmental parameter within the trailer refrigeration unit. The plurality of modes includes a first mode where the at least one compressor and at least one fan are powered by the power converter and a second mode where the at least one compressor is powered by at least one of the plurality of power sources.

Proposed is a gas heat-pump system capable of supplying recirculation exhaust gas to an engine using an exhaust gas turbocharger and thus actively controlling an amount of the flowing recirculation exhaust gas and pressure thereof.

A gas compressor system includes a compression liquid holding tank in fluid communication with a combustion tank. A combustible fluid is directed to the combustion tank. An ignition system is provided for igniting the combustible fluid. A compression liquid flows between the liquid holding tank, the combustion tank, and a compression tank. A compressible gas is provided in the compression tank. The ignition of the combustible fluid drives the compression liquid from the combustion tank to the compression tank, compressing the compressible liquid. An HVAC&R system and a method of compressing gas are also disclosed.

A system comprising a refrigeration engine (132) and regulator (250, 350, 450, 550, 650) positioned within a housing (144, 244), the regulator (250, 350, 450, 550, 650) controlling fuel to the engine through a fuel line (354), a lock-off valve connected to the regulator (250, 350, 450, 550, 650) to shut off fuel supply through the regulator (250, 350, 450, 550, 650), a controller operably connected to the lock-off valve and/or the regulator (250, 350, 450, 550, 650), a guide (462, 562) positioned within the housing (144, 244) and proximate to the refrigeration engine (132), the regulator (250, 350, 450, 550, 650), and/or the fuel line (354) to direct gases leaking from the refrigeration engine (132), regulator (250, 350, 450, 550, 650), and/or at least one fuel line (354), and a methane sensor (566, 666A) positioned within the guide (462, 562) to detect the presence of methane within the guide (462, 562) that is directed by the guide (462, 562), the methane sensor (566, 666A) in communication with the controller and configured to transmit a signal to the controller when methane is detected by the methane sensor (566, 666A). The controller performs a safety action when the signal from the methane sensor (566, 666A) is received.