Patent Description:
A heat pump system includes a refrigeration cycle capable of performing cooling or heating operation and may be interlocked with a hot water supply device or an air conditioning and heating device. That is, hot water may be generated or air conditioning for cooling or heating may be performed using a heat source obtained by heat exchange between refrigerant of a refrigeration cycle and a predetermined heat storage medium.

The refrigeration cycle includes a compressor for compressing refrigerant, a condenser for condensing the refrigerant compressed in the compressor, an expansion device for decompressing the refrigerant condensed in the condenser and an evaporator for evaporating the decompressed refrigerant.

The heat pump system includes a gas heat pump system. A large-capacity compressor is required for air conditioning in industrial or large building, not for home use. That is, as a system which uses a gas engine instead of an electric motor to drive a compressor for compressing a large amount of refrigerant into high-temperature, high-pressure gas, a gas heat pump system may be used.

The gas heat pump system includes an engine for generating power using a mixture of fuel and air (hereinafter referred to as a mixture). For example, the engine may include a cylinder, to which the mixture is supplied, and a piston movably provided in the cylinder.

The gas heat pump system includes an air supply device for supplying the mixture to the engine, a fuel supply device and a mixer for mixing air and fuel.

The air supply device may include an air filter for purifying air. The fuel supply device includes a zero governor for supplying fuel having constant pressure.

The zero governor may be understood as a device for constantly adjusting outlet pressure regardless of the magnitude of the inlet pressure of fuel or change in flow rate of fuel for supplying fuel. For example, the zero governor may include a nozzle unit for reducing the pressure of the fuel, a diaphragm, to which the pressure reduced in the nozzle unit is applied, and a valve device opened and closed by operation of the diaphragm.

Air which has passed through the air filter and the fuel discharged from the zero governor may be mixed in the mixer (to form mixture) and the mixture may be supplied to the engine.

In addition, when the mixture supplied to the engine is burned, exhaust gas may be discharged from the engine. The gas heat pump system further includes a muffler for reducing noise generated in the exhaust gas.

A conventional gas heat pump system is as follows.

The conventional gas heat pump circulates compressor refrigerant using a gas engine using liquefied natural gas (LNG) or liquefied petroleum gas (LPG) for household as a hat source and operates in a cooling mode in the summer and operates in a heating mode in the winter.

However, when air is supplied to the gas engine using a natural aspiration method and LNG or LPG for household is supplied as fuel, output of the gas engine is reduced due to low supply pressure (<NUM> to <NUM> kPa).

In addition, in the summer, the gas heat pump system operates in the cooling mode in order to decrease an indoor temperature. When an outdoor temperature is high, high-temperature gas is supplied to the gas engine due to the high temperature.

Therefore, low-density air is supplied to the gas engine, thereby decreasing output of the gas engine. As a result, the output of the gas engine cannot keep up with a high cooling load, thereby causing cooling failure.

In addition, in order to solve this, as in the engine of a vehicle, after air is pressurized in a supercharger, when the amount of fuel is adjusted according to the amount of air, the supply pressure (about <NUM> kPa) of the gas fuel in the pipe is lower than supercharging pressure (about <NUM> kPa). Therefore, it is difficult to supply fuel. Document <CIT> discloses a gas heat pump system according to the preamble of claim <NUM>.

An object of the present disclosure devised to solve the problem lies in a gas heat pump system capable of improving performance of an engine by supercharging a mixture supplied to the engine.

Another object of embodiments is to provide a gas heat pump system capable of improving maximum output of an engine without increasing the size of the engine.

Another object of embodiments is to provide a gas heat pump system capable of improving volumetric efficiency of an engine by decreasing the temperature of a mixture supplied to the engine and increasing the density of the mixture.

Another object of embodiments is to provide a gas heat pump system capable of preventing safety accidents such as corrosion and explosion of parts by driving an engine until the engine is stopped while blocking inflow of a mixture and burning or discharging a residual mixture to suppress generation of formic acid.

Another object of embodiments is to provide a gas heat pump system capable of smoothly supercharging a mixture regardless of a rotation speed, by supercharging the mixture through a turbocharger in a high-rotation operation region and supercharging the mixture through a supercharger in a low-rotation operation region.

Another object of embodiments is to provide a gas heat pump system capable of supercharging in a wider region by providing a plurality of turbochargers having different turbine capacities.

According to the invention, a gas heat pump system includes the features of claim <NUM>.

An intercooler configured to cool the compressed mixture discharged from the supercharger to improve density may be provided between the supercharger and the adjuster.

The supercharger may be provided as a turbocharger driven by exhaust gas of the engine.

The supercharger may be provided as a supercharger driven by power of the engine or an electric motor.

An exhaust gas heat exchanger, into which exhaust gas discharged from the engine flows, may be provided on the first cooling water pipe, and the cooling water may flow to the engine after passing through the exhaust gas heat exchanger.

The supercharger may include a first supercharger and a second supercharger spaced apart from each other.

The first supercharger and the second supercharger may be different in view of compression capacity or maximum turbine revolution count of a turbine.

The first supercharger and the second supercharger may be connected to each other in series.

The first supercharger and the second supercharger may be connected to each other in parallel.

The gas heat pump system may further include a first fuel pipe provided between the mixer and the first supercharger to guide the mixture obtained in the mixer to the first supercharger, a second fuel pipe branched from the first fuel pipe to guide the mixture to the second supercharger, and a three-way valve installed at an intersection between the first fuel pipe and the second fuel pipe to maintain a flow direction of the mixture discharged from the mixer to the first fuel pipe or change the flow direction to the second fuel pipe.

The first supercharger may be a turbocharger driven by exhaust gas of the engine and the second supercharger may be a supercharger driven by power of the engine or an electric motor.

The first supercharger and the second supercharger may be turbochargers driven by exhaust gas of the engine.

The gas heat pump system may further include a first exhaust gas pipe provided between the engine and the second supercharger to guide exhaust gas discharged from the engine to the first supercharger, a second exhaust gas pipe branched from the first exhaust gas pipe to guide exhaust gas to the second supercharger, and a three-way valve installed at an intersection between the first exhaust gas pipe and the second exhaust gas pipe to maintain a flow direction of the exhaust gas discharged from the engine to the first exhaust gas pipe or change the flow direction to the second exhaust gas pipe.

The fuel may be liquefied natural gas (LNG) or liquefied petroleum gas (LPG) for household.

The engine module may operate the engine in a state of closing the adjuster, immediately before operation of the engine is stopped.

According to the present invention, it is possible to improve volumetric efficiency, by supplying, to an engine, a mixture of fuel and air supplied to a gas engine with pressure higher than natural aspiration using a supercharging unit.

In addition, it is possible to miniaturize the engine and the entire system.

In addition, it is possible to implement a high-capacity gas engine heat pump system with a small gas engine.

In addition, it is possible to improve output of an engine in a gas engine heat pump (GHP) using gas fuel for household.

In addition, it is possible to improve volumetric efficiency of the engine by decreasing the temperature of a mixture supplied to an engine and increasing the density of the mixture.

In addition, it is possible to prevent safety accidents such as corrosion and explosion of parts by driving an engine until the engine is stopped while blocking inflow of a mixture and burning or discharging a residual mixture to suppress generation of formic acid.

In addition, it is possible to smoothly supercharge a mixture regardless of a rotation speed, by supercharging the mixture through a turbocharger in a high-rotation operation region and supercharging the mixture through a supercharger in a low-rotation operation region.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

<FIG> is a cycle diagram showing the configuration of a gas heat pump system according to a first embodiment of the present invention.

Referring to <FIG>, the gas heat pump system <NUM> according to the first embodiment of the present invention includes a plurality of parts configuring a refrigerant cycle as an air conditioning system. Specifically, the refrigerant cycle includes a compressor <NUM> for compressing refrigerant, an oil separator <NUM> for separating oil from the refrigerant compressed in the compressor <NUM> and a four-way valve <NUM> for changing the direction of the refrigerant which has passed through the oil separator <NUM>.

The gas heat pump system <NUM> further includes an outdoor heat exchanger <NUM> and an indoor heat exchanger <NUM>. The outdoor heat exchanger <NUM> may be disposed in an outdoor unit disposed outdoors and the indoor heat exchanger <NUM> may be disposed in an indoor unit disposed indoors. The refrigerant which has passed through the four-way valve <NUM> flows to the outdoor heat exchanger <NUM> or the indoor heat exchanger <NUM>.

Meanwhile, the components of the system shown in <FIG> except for the indoor heat exchanger <NUM> and an indoor expansion device <NUM> may be disposed outdoors, that is, in the outdoor unit.

Specifically, when the system <NUM> operates in a cooling operation mode, the refrigerant which has passed through the four-way valve <NUM> flows to the indoor heat exchanger <NUM> through the outdoor heat exchanger <NUM>. In contrast, when the system <NUM> operates in a heating operation mode, the refrigerant which has passed through the four-way valve <NUM> flows to the outdoor heat exchanger <NUM> through the indoor heat exchanger <NUM>.

The system <NUM> includes further includes a refrigerant pipe <NUM> (solid flow path) for guiding the flow of the refrigerant by connecting the compressor <NUM>, the outdoor heat exchanger <NUM> and the indoor heat exchanger <NUM>.

The configuration of the system <NUM> will be described based on the cooling operation mode.

The refrigerant flowing to the outdoor heat exchanger <NUM> may be condensed through heat exchange with outdoor air. An outdoor fan <NUM> for blowing outdoor air is included at one side of the outdoor heat exchanger <NUM>.

A main expansion device <NUM> for decompressing refrigerant is provided at the outlet side of the outdoor heat exchanger <NUM>. For example, the main expansion device <NUM> includes an electronic expansion valve (EEV). During the cooling operation, the main expansion device <NUM> is fully open not to perform the decompression operation of the refrigerant.

A supercooling heat exchanger <NUM> for further cooling the refrigerant is provided at the outlet side of the main expansion device <NUM>. In addition, the supercooling heat exchanger <NUM> is connected with a supercooling flow path <NUM>. The supercooling flow path <NUM> is branched from the refrigerant pipe <NUM> and is connected to the supercooling heat exchanger <NUM>.

In addition, a supercooling expansion device <NUM> is installed in the supercooling flow path <NUM>. The refrigerant flowing through the supercooling flow path <NUM> may be decompressed while passing through the supercooling expansion device <NUM>.

In the supercooling heat exchanger <NUM>, heat exchange may be performed between the refrigerant in the refrigerant pipe <NUM> and the refrigerant in the supercooling flow path <NUM>. In the heat exchange process, the refrigerant in the refrigerant pipe <NUM> is supercooled, and the refrigerant in the supercooling flow path <NUM> absorbs heat.

The supercooling flow path <NUM> is connected to a gas-liquid separator <NUM>. The refrigerant in the supercooling flow path <NUM> which has exchanged heat in the supercooling heat exchanger <NUM> may flow into the gas-liquid separator <NUM>.

The refrigerant in the refrigerant pipe <NUM>, which has passed through the supercooling heat exchanger <NUM>, flows to the indoor unit and is decompressed in the indoor expansion device <NUM> and then is evaporated in the indoor heat exchanger <NUM>. The indoor expansion device <NUM> is installed inside the indoor unit and may be composed of an electronic expansion valve (EEV).

The refrigerant evaporated in the indoor heat exchanger <NUM> flows to an auxiliary heat exchanger <NUM> through the four-way valve <NUM>. The auxiliary heat exchanger <NUM> refers to a heat exchanger capable of exchanging heat between the evaporated low-pressure refrigerant and high-temperature cooling water and may include a plate type heat exchanger.

The refrigerant evaporated in the indoor heat exchanger <NUM> may absorb heat while passing through the auxiliary heat exchanger <NUM>, thereby improving evaporation efficiency. In addition, the refrigerant which has passed through the auxiliary heat exchanger <NUM> may flow into the gas-liquid separator <NUM>.

The refrigerant which has passed through the auxiliary heat exchanger <NUM> is separated into gas and liquid in the gas-liquid separator <NUM>, and the separated gaseous refrigerant may be sucked into the compressor <NUM>.

In addition, the refrigerant evaporated in the indoor heat exchanger <NUM> may immediately flow into the gas-liquid separator <NUM> through the four-way valve <NUM>, and the separated gaseous refrigerant may be sucked into the compressor <NUM>.

Meanwhile, the gas heat pump system <NUM> further includes a cooling water tank <NUM> in which cooling water for cooling an engine <NUM> is stored and a cooling water pipe <NUM> (dotted flow path) for guiding the flow of cooling water. In the cooling pipe <NUM>, a cooling water pump <NUM> for generating the flow force of the cooling water, a plurality of flow switching units <NUM> and <NUM> for changing the flow direction of the cooling water, and a radiator <NUM> for cooling the cooling water.

The plurality of flow changing units <NUM> and <NUM> includes a first flow charging unit <NUM> and a second flow changing unit <NUM>. For example, the first flow changing unit <NUM> and the second flow changing unit <NUM> may include <NUM>-way valves.

The radiator <NUM> may be installed at one side of the outdoor heat exchanger <NUM>, and the cooling water of the radiator <NUM> may exchange heat with outdoor air by driving of the outdoor fan <NUM>. In this process, cooling may be performed.

When the cooling water pump <NUM> is driven, the cooling water stored in the cooling water tank <NUM> may pass through the engine <NUM> and an exhaust gas heat exchanger <NUM>, and selectively flow to the radiator <NUM> or the auxiliary heat exchanger <NUM> through the first flow changing unit <NUM> and the second flow changing unit <NUM>.

The gas heat pump system <NUM> includes the engine <NUM> for generating power for driving the compressor <NUM> and a mixer <NUM> disposed at the inlet side of the engine <NUM> to supply mixed fuel.

In addition, the gas heat pump system <NUM> includes an air filter <NUM> for supplying purified air to the mixer <NUM> and a zero governor <NUM> for supplying fuel having a predetermined pressure or less. The zero governor may be understood as a device for constantly adjusting outlet pressure regardless of the magnitude of the inlet pressure of fuel or change in flow rate of fuel and supplying fuel.

Air which has passed the air filter <NUM> and fuel discharged from the zero governor <NUM> may be mixed in the mixer <NUM> to configure a mixture. In addition, the mixture may be supplied to the engine <NUM>.

In addition, the gas heat pump system <NUM> further includes an exhaust gas heat exchanger <NUM> provided at the outlet side of the engine <NUM> to receive exhaust gas generated after the mixture is burned and a muffler <NUM> provided at the outlet side of the exhaust gas heat exchanger <NUM> to reduce noise of exhaust gas. In the exhaust gas heat exchanger <NUM>, heat is exchanged between cooling water and exhaust gas.

In addition, an oil tank <NUM> for supplying oil to the engine <NUM> may be provided at one side of the engine <NUM>.

Meanwhile, the engine <NUM> applied to the gas heat pump system <NUM> uses LNG or LPG for household as fuel.

However, when LNG or LPG for household is supplied as fuel while supplying air to the engine <NUM> using a natural aspiration method, the output of the engine <NUM> may be reduced due to low supply pressure (<NUM> to <NUM> kPa).

In addition, in the summer, the gas heat pump system <NUM> operates in the cooling mode in order to reduce the indoor temperature. When the outdoor temperature is high, high-temperature air is supplied to the engine <NUM> due to the high temperature.

Therefore, low-density air is supplied to the engine <NUM> to reduce the output of the engine <NUM>. As a result, the output of the engine <NUM> cannot keep up with a high cooling load, thereby causing cooling failure.

In addition, in order to solve this, as in the engine of a vehicle, after air is pressurized in a supercharger, when the amount of fuel is controlled according to the amount of air, the supply pressure (about <NUM> kPa) of the gas fuel in the pipe is lower than supercharging pressure (about <NUM> kPa). Therefore, it is difficult to supply fuel.

In the present invention, in order to solve this problem, a supercharging unit <NUM> and an adjustment unit <NUM> are provided between the mixer <NUM> and the engine <NUM>.

Specifically, the supercharging unit <NUM> compresses the mixture discharged after air and fuel are mixed in the mixer <NUM> and discharge the mixture to the engine <NUM>. At this time, the supercharging unit <NUM> may compress air and fuel mixed in the mixer <NUM> to atmospheric pressure or more.

For example, the supercharging unit <NUM> is provided as a turbocharger driven by the exhaust gas of the engine <NUM>.

As another example, the supercharging unit <NUM> may be provided as a supercharger driven by power of the engine <NUM> or an electric motor.

In addition, the adjusting unit <NUM> is disposed between the supercharging unit <NUM> and the engine <NUM> to adjust the amount of compressed mixture supplied to the engine <NUM>.

For example, the adjusting unit <NUM> may be provided as a valve to which an ETC (electronic throttle control) method is applied.

According to the present invention, fuel and air may be mixed in the mixer <NUM>, be compressed to high pressure in the supercharging unit <NUM>, and be supplied to the engine <NUM>. In addition, the amount of mixture (air + fuel) supplied to the engine <NUM> through the adjusting unit <NUM> may be precisely controlled.

Accordingly, efficiency of the engine <NUM> may be improved. In addition, it is possible to increase the maximum output of the engine <NUM>, without increasing the size of the engine <NUM>. That is, the output of a large engine may be implemented by a small engine.

Meanwhile, as described above, when the mixture passes through the supercharging unit <NUM>, the pressure and temperature of the mixture increase. In this case, the density of the mixture sucked into the engine <NUM> may be reduced and the volumetric efficiency of the engine may be reduced.

In the present invention, in order to solve this, an intercooler <NUM> for cooling the high-temperature, high-pressure mixture discharged from the supercharging unit <NUM> to reduce the volume and density of the mixture and then discharging the mixture is provided between the supercharging unit <NUM> and the adjusting unit <NUM>.

For example, the intercooler <NUM> may enable heat exchange between outdoor air or cooling water and the mixture.

Therefore, it is possible to decrease the temperature of the mixture supplied to the engine <NUM> and increase the density of the mixture to improve the volumetric efficiency of the engine <NUM>.

Meanwhile, as described above, when the supercharging unit <NUM> and the intercooler <NUM> are provided between the mixer <NUM> and the engine <NUM>, the length of the flow path in which the mixture stays may inevitably increase. At this time, when a lot of moisture is included in air, the mixture and water react to generate formic acid, such that the pipe may be damaged and exploded.

In the present invention, in order to prevent this problem, when an administrator inputs an "operation stop command", the engine <NUM> may be driven in a state of closing the adjusting unit <NUM> until the engine <NUM> is stopped, thereby burning or discharging the mixture. Therefore, it is possible to suppress generation of formic acid and prevent damage to and explosion of the pipe.

In addition, the intercooler <NUM> may be made of a corrosion-resistant material (e.g., STS316).

Meanwhile, the cooling pipe <NUM> includes a first pipe <NUM> extending from the cooling water tank <NUM> to the engine <NUM>. Specifically, the first pipe <NUM> includes a first pipe part extending from the cooling water tank <NUM> to the exhaust gas heat exchanger <NUM> and a second pipe part extending from the exhaust gas heat exchanger <NUM> to the engine <NUM>. Accordingly, cooling water supplied from the cooling water tank <NUM> exchanges heat with exhaust gas while passing through the exhaust gas heat exchanger <NUM>, and flows into the engine <NUM> to recover waste heat of the engine <NUM>. In addition, the first pipe <NUM> may be provided with the cooling water pump <NUM> for generating flow of cooling water.

The cooling pipe <NUM> further includes a second pipe <NUM> for guiding cooling water which has passed through the engine <NUM> to the first flow changing unit <NUM>.

In addition, the cooling pipe <NUM> further includes a third pipe <NUM> for guiding cooling water from the first flow changing unit <NUM> to the second flow changing unit <NUM>.

In addition, the cooling pipe <NUM> further includes a fourth pipe <NUM> for guiding cooling water from the second flow changing unit <NUM> to the auxiliary heat exchanger <NUM>.

The cooling pipe <NUM> further includes a fifth pipe <NUM> for guiding cooling water from the second flow changing unit <NUM> to the radiator <NUM>.

The cooling pipe <NUM> further includes a sixth pipe <NUM> for guiding cooling water from the first flow changing unit <NUM> to the first pipe <NUM>.

For example, when the temperature of the cooling water which has passed the engine <NUM> is less than a set temperature, the cooling water may flow to the auxiliary heat exchanger <NUM> or the radiator <NUM>, thereby reducing heat exchange effect. Therefore, the cooling water flowing into the first flow changing unit <NUM> may be bypassed to the first pipe <NUM> through the sixth pipe <NUM>. The sixth pipe <NUM> may be referred to as a "bypass pipe".

The gas heat pump system <NUM> may further include a cooling water temperature sensor <NUM> installed at the outlet side of the engine <NUM> to detect the temperature of the cooling water which has passed the engine <NUM>.

Hereinafter, operation of the refrigerant, cooling water and mixed fuel according to the operation mode of the gas heat pump system <NUM> according to the first embodiment of the present invention will be described.

<FIG> is a cycle diagram showing the flow of refrigerant, cooling water, mixed fuel during heating operation of the gas heat pump system.

First, when the gas heat pump system <NUM> performs heating operation, refrigerant is decompressed in the main expansion device <NUM> after passing through the compressor <NUM>, the oil separator <NUM>, the four-way valve <NUM>, the indoor heat exchanger <NUM> and the supercooling heat exchanger <NUM>, is subjected to heat exchange in the outdoor heat exchanger <NUM>, and then is introduced into the four-way valve <NUM> again. Here, the indoor heat exchanger <NUM> may function as a "condenser", and the outdoor heat exchanger <NUM> may function as an "evaporator".

The refrigerant which has passed through the four-way valve <NUM> may flow into the auxiliary heat exchanger <NUM>, thereby exchanging heat with cooling water flowing through the fourth pipe <NUM>. The refrigerant flowing into the auxiliary heat exchanger <NUM> is evaporative refrigerant having a high temperature and low pressure, and the cooling water supplied to the auxiliary heat exchanger <NUM> has a high temperature by heat of the engine <NUM>. Accordingly, the refrigerant of the auxiliary heat exchanger <NUM> may absorb heat from the cooling water, thereby improving evaporation performance.

The refrigerant which has exchanged heat in the auxiliary heat exchanger <NUM> may be introduced into the gas-liquid separator <NUM> to be phase-separated and then be sucked into the compressor <NUM>. The refrigerant may repeatedly flow in the cycle.

Meanwhile, when the cooling water pump <NUM> is driven, the cooling water discharged from the cooling water pump <NUM> is introduced into the exhaust gas heat exchanger <NUM> along the first pipe <NUM>, thereby exchanging heat with exhaust gas. In addition, the cooling water discharged from the exhaust gas heat exchanger <NUM> flows into the engine <NUM> to cool the engine <NUM> and flows into the first flow changing unit <NUM> through the second pipe <NUM>.

Under control of the first flow changing unit <NUM>, the cooling water which has passed through the first flow changing unit <NUM> flows toward the second flow changing unit <NUM> along the third pipe <NUM>. In addition, the cooling water which has passed through the second flow changing unit <NUM> may flow into the auxiliary heat exchanger <NUM> through the fourth pipe <NUM>, thereby exchanging heat with refrigerant. In addition, the cooling water which has passed through the auxiliary heat exchanger <NUM> flows into the cooling water pump <NUM>. The cooling water may repeatedly flow in such a cycle.

Meanwhile, during heating operation, flow of cooling water to the radiator <NUM> may be limited. In general, since heating operation is performed when an outdoor temperature is low, the cooling water is highly likely to be cooled when flowing through the cooling pipe <NUM>, even if the cooling water is not cooled in the radiator <NUM>. Accordingly, during heating operation, the first and second flow switching units <NUM> and <NUM> may be controlled such that the cooling water does not pass through the radiator <NUM>.

However, when heat exchange in the auxiliary heat exchanger <NUM> is unnecessary, the cooling water may flow from the second flow changing unit <NUM> into the radiator <NUM> through the fifth pipe <NUM>.

Driving of the engine <NUM> will be described.

Air filtered in the air filter <NUM> and fuel, the pressure of which is adjusted through the zero governor <NUM>, are mixed in the mixer <NUM>. The mixture obtained in the mixer <NUM> is pressurized in the supercharging unit <NUM> and the pressurized mixture is cooled in the intercooler <NUM>, thereby improving density of the mixture. The amount of mixture which has passed through the intercooler <NUM> is adjusted through the adjusting unit <NUM>, and the mixture is supplied to the engine <NUM> to operate the engine <NUM>. In addition, the exhaust gas discharged from the engine <NUM> is introduced into the exhaust gas heat exchanger <NUM> to exchange heat with the cooling water and is discharged to the outside through the muffler <NUM>.

<FIG> is a cycle diagram showing the flow of refrigerant, cooling water, mixed fuel during cooling operation of the gas heat pump system.

Meanwhile, when the gas heat pump system <NUM> performs cooling operation, the refrigerant is decompressed in the indoor expansion device <NUM> after passing through the compressor <NUM>, the oil separator <NUM>, the four-way valve <NUM>, the outdoor heat exchanger <NUM> and the supercooling heat exchanger <NUM>, is subjected to heat exchange in the indoor heat exchanger <NUM>, and is introduced into the four-way valve <NUM> again. Here, the outdoor heat exchanger <NUM> may function as a "condenser" and the indoor heat exchanger <NUM> may function as an "evaporator".

The refrigerant which has passed through the four-way valve <NUM> may flow into the auxiliary heat exchanger <NUM> and exchange heat with the cooling water flowing through the cooling pipe <NUM>. In addition, the refrigerant which has exchanged heat in the auxiliary heat exchanger <NUM> may be introduced into the gas-liquid separator <NUM> to be phase-separated and then sucked into the compressor <NUM>. The refrigerant may repeatedly flow in the cycle.

Meanwhile, when the cooling water pump <NUM> is driven, the cooling water discharged from the cooling water pump <NUM> flows into the exhaust gas heat exchanger <NUM> and exchanges heat with exhaust gas. In addition, the cooling water discharged from the exhaust gas heat exchanger <NUM> flows into the engine <NUM> to cool the engine <NUM> and flows into the first flow changing unit <NUM>. Flow of the cooling water until flowing into the first flow changing unit <NUM> is equal to flow of cooling water during heating operation.

The cooling water which has passed through the first flow changing unit <NUM> may flow into the second flow changing unit <NUM>, and flow through the radiator <NUM> to exchange heat with outdoor air under control of the second flow changing unit <NUM>. In addition, the cooling water cooled in the radiator <NUM> flows into the cooling water pump <NUM>. The cooling may repeatedly flow in such a cycle.

Meanwhile, during cooling operation, flow of the cooling water to the auxiliary heat exchanger <NUM> may be limited. In general, since cooling operation is performed when an outdoor temperature is high, heat absorption of evaporative refrigerant for securing evaporation performance may not be required. Accordingly, during cooling operation, the first and second flow switching units <NUM> and <NUM> may be controlled such that cooling water does not pass through the auxiliary heat exchanger <NUM>.

However, when heat exchange in the auxiliary heat exchanger <NUM> is necessary, cooling water may flow into the auxiliary heat exchanger <NUM> through the second flow changing unit <NUM>.

For driving of the engine <NUM>, the same operation as heating operation is performed and thus a detailed description thereof will be omitted.

<FIG> are systematic diagrams showing various embodiments of an engine module as a component of the present invention.

First, referring to <FIG>, the supercharging unit <NUM> may be provided as a turbocharger.

The "turbocharger" rotates a turbine <NUM> using the exhaust gas discharged from the engine <NUM> and pressurizes (compresses) gas introduced by rotation force to discharge gas.

Accordingly, when the supercharging unit <NUM> is provided as a turbocharger, the turbine <NUM> of the turbocharger is connected to the exhaust manifold of the engine <NUM> through an exhaust gas pipe <NUM> and is rotated, and the mixture obtained in the mixer is introduced, is pressurized (compressed), and is discharged to the intercooler <NUM>.

In addition, the rotation shaft of the turbocharger may receive oil from the engine <NUM>, for the purpose of lubrication.

Meanwhile, as described above, when the supercharging unit <NUM> is a turbocharger, heat dissipation of the turbocharger is required. For example, the turbocharger may dissipate heat while exchanging heat with cooling water.

For heat dissipation of the turbocharger, the cooling water pipe <NUM> may include a first cooling water pipe 360a and a second cooling water pipe 360b.

Specifically, the first cooling water pipe 360a is disposed between the exhaust gas heat exchanger <NUM> and the engine <NUM> to guide the cooling water which has passed through the exhaust gas heat exchanger <NUM> to the engine <NUM>.

As another example, the first cooling water pipe 360a may also include a cooling water pipe before passing through the exhaust gas heat exchanger <NUM>. That is, the first cooling water pipe 360a may mean a cooling water pipe between the cooling water pipe <NUM> and the engine <NUM>.

The second cooling water pipe 360b is branched from the first cooling water pipe 360a such that at least some of the cooling water flowing through the first cooling water pipe 360a exchanges heat with the supercharging unit <NUM>. The cooling water introduced into the second cooling water pipe 360a flows to the engine <NUM> through the supercharging unit <NUM>.

At this time, the second cooling water pipe 360b may be branched from the first cooling water pipe 360a before the supercharging unit <NUM> and combined with the first cooling water pipe 360a after passing through the supercharging unit <NUM>, such that cooling water is supplied to the engine <NUM>.

Meanwhile, referring to <FIG>, the supercharging unit <NUM> may be provided as a supercharger.

The supercharger generates rotation force by power of the engine <NUM> or an electric motor, pressurizes (compresses) the introduced gas and discharges the gas. Accordingly, when the supercharging unit <NUM> is provided as a supercharger, the supercharger may pressurize (supercharge) the mixture obtained in the mixer using power of the engine <NUM> or the rotation force of the electric motor and discharge the mixture to the intercooler <NUM>.

In general, the supercharger tends to stably operate in a low rotation region and cause output loss in a high rotation region. Accordingly, according to operation condition and required output condition of the engine, the supercharging unit <NUM> may be selectively used as a supercharger or a turbocharger.

Meanwhile, as described above, when the supercharging unit <NUM> is a supercharge, heat dissipation is not caused as in the turbocharger. Therefore, the cooling water pipe for cooling the supercharging unit <NUM> may not be further installed. Accordingly, the structure of the flow path is simplified, space utilization is improved and miniaturization is possible.

<FIG> is a view showing an embodiment in which a turbocharger and a supercharger are provided as supercharging units and are connected to each other in parallel. <FIG> is a view showing an embodiment in which two turbochargers are provided as supercharging units and are connected to each other in parallel.

Referring to <FIG>, a plurality of supercharging units <NUM> spaced apart from each other may be provided and, for example, a first supercharging unit <NUM> and a second supercharging unit <NUM> may be included.

When one supercharging unit <NUM> is disposed between the engine <NUM> and the mixer <NUM>, a supercharging range may be limited by the maximum revolution count or compression capacity of the disposed supercharging unit <NUM>, and, as a result, the output improvement range of the engine <NUM> may be limited.

In the present invention, the plurality of supercharging units <NUM> may be disposed such that the operation region of the supercharging unit <NUM> is widened and thus the output improvement range of the engine is further widened.

Although the supercharging unit <NUM> includes the first supercharging unit <NUM> and the second supercharging unit <NUM> in the following description, the present invention is not limited thereto and three or more supercharging units may be provided between the mixer <NUM> and the adjusting unit <NUM>.

In addition, although the plurality of supercharging units <NUM> is connected in parallel and the mixture obtained in the mixer <NUM> is supplied to the engine <NUM> after flowing to the first supercharging unit <NUM> or the second supercharging unit <NUM>, the first and second supercharging units <NUM> and <NUM> may be connected in series and thus the mixture obtained in the mixer <NUM> may be supplied to the engine <NUM> after sequentially passing through both the first supercharging unit <NUM> and the second supercharging unit <NUM>.

In the first supercharging unit <NUM> and the second supercharging unit <NUM>, compression capacity and the maximum revolution count of the turbine may be differently set.

Hereinafter, the flow process of the mixture and the flow process of the cooling water in different embodiments will be described with reference to <FIG> and <FIG>.

First, referring to <FIG>, the first and second supercharging units <NUM> and <NUM> are provided as a turbocharger and a supercharger, respectively.

In addition, a first fuel pipe <NUM> for guiding the mixture obtained in the mixer <NUM> to the first supercharging unit <NUM> is provided between the mixer <NUM> and the first supercharging unit <NUM>, and a second fuel pipe <NUM> for guiding the mixture to the second supercharging unit <NUM> is branched from the first fuel pipe <NUM>.

In addition, a three-way valve <NUM> for maintaining the flow direction of the mixture discharged from the mixer <NUM> to the first fuel pipe <NUM> or changing the flow direction to the second fuel pipe <NUM> may be installed in an intersection between the first fuel pipe <NUM> and the second fuel pipe <NUM>.

The mixture which has passed through the first supercharging unit <NUM> or the mixture which has passed through the second supercharging unit <NUM> flow into the intercooler <NUM>.

In the present embodiment, the first supercharging unit <NUM> is a turbocharger and the second supercharging unit <NUM> is a supercharger.

In general, in the case of the turbocharger, since the turbine rotates using the exhaust gas of the engine <NUM>, the turbocharger is advantageous in a high rotation region and a "turbo lag" phenomenon in which output is instantaneously delayed occurs in a low rotation region.

In contrast, the supercharger may work well at a low revolution count, but output loss may occur in a high rotation region.

The three-way valve <NUM> may enable the mixture to flow to the first supercharging unit <NUM> which is a turbocharger in the case of a high-rotation operation region (when the flow rate of exhaust gas is sufficient to rotate the turbine) and enable the mixture to flow to the second supercharging unit <NUM> which is a supercharger such that the mixture is smoothly pressurized regardless of the rotation speed in the case of a low-rotation operation region (when the flow rate of exhaust gas is insufficient to rotate the turbine).

At this time, the three-way valve <NUM> may be set to basically supply the mixture to the first supercharging unit <NUM> which is the turbocharger, and temporarily supply the mixture to the second supercharging unit <NUM> which is the supercharger only in a low rotation region (until the flow rate of exhaust gas for driving the turbocharger is output).

That is, the second supercharging unit <NUM> which is the supercharger may be understood as the supporter of the first supercharging unit <NUM> which is the turbocharger.

Meanwhile, referring to <FIG>, both the first and second supercharging units <NUM> and <NUM> are provided as turbochargers.

The turbines <NUM> and <NUM> of the first and second supercharging units <NUM> and <NUM> receive the exhaust gas of the engine <NUM> to generate rotation force.

To this end, a first exhaust gas pipe <NUM> for guiding the exhaust gas discharged from the engine <NUM> to the first supercharging unit <NUM> is provided between the engine <NUM> and the first supercharging unit <NUM>, and a second exhaust gas pipe <NUM> for guiding the exhaust gas to the second supercharging unit <NUM> is branched from the first exhaust gas pipe <NUM>.

In addition, a three-way valve <NUM> for maintaining the flow direction of the exhaust gas discharged from the exhaust manifold of the engine <NUM> to the first exhaust gas pipe <NUM> or changing the flow direction to the second exhaust gas pipe <NUM> may be installed in an intersection between the first exhaust gas pipe <NUM> and the second exhaust gas pipe <NUM>.

At this time, the first and second supercharging units <NUM> and <NUM> may be provided as turbochargers having different turbine capacities. In this case, supercharging is possible in a wider region than the case where one supercharging unit is installed.

For example, the capacity Q1 of the turbine <NUM> provided in the first supercharging unit <NUM> may be greater than the capacity Q2 of the turbine <NUM> provided in the second supercharging unit <NUM> (Q1>Q2).

Accordingly, the three-way valve <NUM> may enable the mixture to flow to the first supercharging unit <NUM> having the turbine <NUM> having a large capacity when output of the engine <NUM> having greater than a predetermined reference value needs to be improved and enable the mixture to flow to the second supercharging unit <NUM> having the turbine <NUM> having a small capacity when output of the engine <NUM> having less than the predetermined reference value needs to be improved, thereby performing supercharging in a wider region.

At this time, the three-way valves <NUM> and <NUM> may be interlocked with each other.

First, when the mixture flows to the first supercharging unit <NUM>, the three-way valves <NUM> and <NUM> may be open toward only the first supercharging unit <NUM> and closed toward the second supercharging unit <NUM>.

In contrast, when the mixture flows to the second supercharging unit <NUM>, the three-way valves <NUM> and <NUM> may be open toward the second supercharging unit <NUM> and closed toward the first supercharging unit <NUM>.

In addition, as described above, when both the first supercharging unit <NUM> and the second supercharging unit <NUM> are turbochargers, flow of the cooling water for cooling the first supercharging unit <NUM> and the second supercharging unit <NUM> is necessary.

To this end, the cooling water pipe <NUM> may include the first cooling water pipe 360a, the second cooling water pipe 360b and a third cooling water pipe 360c.

Specifically, the first cooling water pipe 360a is disposed between the exhaust gas heat exchanger <NUM> and the engine <NUM> to guide the cooling water which has passed through the exhaust gas heat exchanger <NUM> toward the engine <NUM>.

The second cooling water pipe 360b is branched from the first cooling water pipe 360a such that at least some of the cooling water flowing through the first cooling water pipe 360a exchanges heat with the first supercharging unit <NUM>. The cooling water introduced into the second cooling water pipe 360a may flow to the engine <NUM> through the first supercharging unit <NUM>.

At this time, the second cooling water pipe 360b may be branched from the first cooling water pipe 360a before the first supercharging unit <NUM>, and combined with the first cooling water pipe 360a after passing through the first supercharging unit <NUM>, such that cooling water is supplied to the engine <NUM>.

Meanwhile, the third cooling water pipe 360c may be branched from the cooling water pipe <NUM> before the exhaust gas heat exchanger <NUM> to supply cooling water to the second supercharging unit <NUM>.

In addition, the third cooling water pipe 360c may be branched from the first cooling water pipe 360a such that at least some of the cooling water flowing through the first cooling water pipe 360a exchanges heat with the second supercharging unit <NUM>. At this time, the cooling water introduced into the third cooling water pipe 360c flows to the engine <NUM> through the second supercharging unit <NUM>.

At this time, the third cooling water pipe 360c may be branched from the first cooling water pipe 360a before the second supercharging unit <NUM> and combined with the first cooling water pipe 360a after passing through the second supercharging unit <NUM>, such that cooling water is supplied to the engine <NUM>.

In addition, valves (not shown) may be installed in the second cooling water pipe 360b and the third cooling water pipe 360c.

Accordingly, when the mixture flows to the first supercharging unit <NUM>, the valve of the third cooling water pipe 360c is closed and the valve of the second cooling water pipe 360b is opened, such that the cooling water flows to only the second cooling water pipe 360b.

Claim 1:
A gas heat pump system comprising:
an air conditioning module including a compressor (<NUM>), an outdoor heat exchanger (<NUM>), an expansion device (<NUM>), an indoor heat exchanger (<NUM>) and a refrigerant pipe (<NUM>);
an engine module including an engine (<NUM>) configured to burn a mixture of fuel and air and provide power for operation of the compressor (<NUM>); and
a cooling module including a cooling water pump (<NUM>) configured to generate flow of cooling water for cooling the engine (<NUM>) and a cooling water pipe (<NUM>) connected to the cooling water pump (<NUM>) to guide flow of cooling water,
wherein the engine module includes:
a mixer (<NUM>) configured to discharge the mixture of air and fuel to the engine (<NUM>);
characterized in that
the engine module further includes:
a supercharger disposed between the mixer (<NUM>) and the engine (<NUM>) to compress the mixture discharged from the mixer (<NUM>) and discharge the mixture to the engine (<NUM>); and
an adjuster disposed between the supercharger and the engine (<NUM>) to adjust an amount of compressed mixture supplied to the engine (<NUM>);
wherein the cooling water pipe (<NUM>) includes:
a first cooling water pipe (360a) configured to guide the cooling water discharged from the cooling water pump (<NUM>) to the engine (<NUM>); and
a second cooling water pipe (360b) branched from the first cooling water pipe (360a) and passing through the supercharger, such that heat is exchanged between at least some cooling water and the supercharger; and
wherein the second cooling water pipe (360b) is branched from the first cooling water pipe (360a) before the supercharger and combed with the first cooling water pipe (360a) after passing through the supercharger.