Gas heat pump system

Abstract

Gas heat pump system that features: a compressor of an air conditioning module; a gas engine that generates a driving force for the compressor; an exhaust gas turbocharger that feeds at least a proportion of exhaust gas emitted from the gas engine back to the gas engine as recirculated exhaust gas; and an exhaust gas sensor configured to detect the concentration of pollutants contained in the exhaust gas; and a control unit that controls the operation of the exhaust gas turbocharger, the exhaust gas turbocharger features: a turbocharger impeller that exerts pressure on the recirculated exhaust gas and feeds the resulting recirculated exhaust gas to the gas engine; and a turbocharger motor that rotates the turbocharger impeller, and the control system is adjusted to increase the speed of the turbocharger motor, when the measured concentration is equal to or higher than a first reference concentration.

Description

Background of the invention; Field of the invention

[0001] The disclosure relates to a gas heat pump system and in particular a gas heat pump system that can supply recirculated exhaust gas by means of a motor-driven turbocharger and thereby actively control the quantity of flowing recirculated exhaust gas and its pressure. Description of the related technique

[0002] A heat pump system is a system that can perform cooling or heating operations via a refrigeration cycle and works in cooperation with a hot water supply device or a cooling and heating device.

[0003] This means that hot water is generated or air conditioning is used for cooling and heating with the help of a heat source that results from heat exchange between a cooling refrigerant in the refrigeration cycle and a predetermined heat storage medium.

[0004] In general, a refrigeration circuit configuration requires that it includes a compressor to compress refrigerant, a condenser to condense the refrigerant compressed by the compressor, an expansion device to decompress the refrigerant condensed by the condenser, and an evaporator to evaporate the decompressed refrigerant.

[0005] Depending on the type of drive source used to power the compressor, heat pump systems can be divided into electric heat pump systems and gas heat pump systems.

[0006] Electric heat pump systems with a low load capacity are suitable for domestic use.

[0007] Gas heat pump systems with high load capacity are suitable for commercial use or large buildings.

[0008] Therefore, instead of an electric motor, the gas heat pump system uses a gas engine to drive a high-performance compressor suitable for this high load capacity.

[0009] The gas heat pump system is configured to include an internal combustion engine that burns a mixture of gaseous fuel and air (hereinafter referred to as fuel-air mixture) and thereby generates a driving force, a fuel supply device, a mixer for mixing air and gaseous fuel, and a device for supplying the fuel-air mixture to the internal combustion engine.

[0010] Since the gas heat pump system uses a driving force from the combustion engine, which is generated by burning the fuel-air mixture, pollutants that contaminate the atmosphere are contained in the exhaust gas, which is produced in a combustion process of the fuel-air mixture.

[0011] In general, exhaust gas recirculation (EGR) technology, in which a portion of the exhaust gas is fed back into the intake manifold of the combustion engine, is used as a means of reducing the amount of pollutants produced that are contained in the exhaust gas.

[0012] The Korean patent application KR 10 2018 0 015 900 A (patent citation 1) discloses a turbocharger that rotates an impeller using a turbine as a drive source, which is rotated with the exhaust gas, and an exhaust gas recirculation device that returns a portion of the exhaust gas delivered via the turbine to the inlet line.

[0013] With a configuration disclosed in patent citation 1, the amount of flowing recirculated exhaust gas is simply adjusted using an exhaust gas recirculation valve.

[0014] Therefore, in a case where the pressure of the exhaust gas being released and recirculated is lower than the pressure of the inlet line, recirculation is not possible.

[0015] Furthermore, the configuration disclosed in patent citation 1 does not allow for the control of the amount of recirculated exhaust gas based on the concentration of pollutants contained in the discharged exhaust gas or the amount of substance discharged. For this reason, the combustion engine cannot be operated efficiently.

[0016] DE 102016 122 311 A1 discloses various methods and systems for emission control.

[0017] WO 2015 / 029900 A1 discloses an exhaust pressure reduction device and an exhaust pressure reduction method for an internal combustion engine.

[0018] The JP 2002-332 919 A ​​reveals an exhaust gas recirculation system.

[0019] EP 2 993 334 B1 discloses a gas engine with a control of the air-fuel ratio depending on changes in composition.

[0020] The foregoing description is intended only to help in understanding the background of the disclosure and is not intended to imply that the disclosure falls within the scope of related technology already known to the person skilled in the art. Summary of the invention

[0021] The disclosure is based on the task of providing a gas heat pump system that can supply recirculated exhaust gas using a motor-driven turbocharger and thereby actively control the quantity of flowing recirculated exhaust gas and its pressure.

[0022] Another objective of the disclosure is to provide a gas heat pump system that can monitor in real time the concentration of pollutants contained in the exhaust gas and adjust the amount of recirculated exhaust gas based on the monitoring results. In the gas heat pump system, the amount of pollutants produced can be significantly reduced, and the operating efficiency of an internal combustion engine can be improved.

[0023] According to one aspect of the disclosure, a gas heat pump system is provided comprising: a compressor of a climate module; a gas engine generating a driving force for the compressor; an exhaust gas turbocharger feeding at least a proportion of exhaust gas emitted by the gas engine back to the gas engine as recirculated exhaust gas; and a control unit regulating the operation of the exhaust gas turbocharger, wherein the exhaust gas turbocharger comprises: a turbocharger impeller that exerts pressure on the recirculated exhaust gas and feeds the resulting recirculated exhaust gas back to the gas engine; and a turbocharger motor that rotates the turbocharger impeller, and the control unit regulates the speed of the turbocharger motor according to a concentration of pollutants contained in the exhaust gas.

[0024] Furthermore, the gas heat pump system can include: an exhaust pipe through which the exhaust gas from the gas heat pump system is discharged to the outside; an exhaust gas sensor attached to the exhaust pipe, wherein the exhaust gas sensor is configured to detect the concentration of pollutants contained in the exhaust gas; and an exhaust gas bypass pipe branching off upstream from the exhaust pipe from a position where the exhaust gas sensor is attached, wherein the exhaust gas bypass pipe is configured to direct the recirculated exhaust gas to the exhaust gas turbocharger, wherein the control unit can receive a signal corresponding to the concentration of pollutants from the exhaust gas and can measure the concentration of pollutants.

[0025] Pollutants in gas heat pump systems can include carbon monoxide, nitrogen oxides and / or hydrocarbons.

[0026] In the gas heat pump system, the control unit compares the measured concentration with a first reference concentration and determines whether the measured concentration exceeds the first reference concentration. If the measured concentration is equal to or higher than the first reference concentration, the control unit increases the speed of the turbocharger motor and can thereby increase the turbocharge quantity of the recirculated exhaust gas.

[0027] Furthermore, the gas heat pump system can include: an intake manifold that supplies a fuel-air mixture to the gas engine; an intake manifold pressure sensor that detects the pressure of the fuel-air mixture in the intake manifold; and a recirculation exhaust gas pressure sensor that detects the turbocharger pressure of the recirculation exhaust gas discharged from the exhaust gas turbocharger, wherein the control unit can receive a signal corresponding to the pressure of the fuel-air mixture from the intake manifold pressure sensor and can measure the pressure of the fuel-air mixture, and the control unit can receive a signal corresponding to the pressure of the recirculation exhaust gas from the recirculation exhaust gas pressure sensor and can measure the turbocharger pressure of the recirculation exhaust gas supplied to the intake manifold.

[0028] In the gas heat pump system, the control unit can calculate a pressure difference between the measured pressure of the fuel-air mixture and the measured turbocharger pressure of the recirculated exhaust gas, and can calculate a target turbocharger pressure of the recirculated exhaust gas.

[0029] In the gas heat pump system, the control unit can calculate the current speed of the turbocharger motor and can increase the speed of the turbocharger motor to a target speed, which is obtained by adding a predetermined increase to the calculated current speed.

[0030] In a gas heat pump system, the predetermined increase can be 1,000 rpm.

[0031] In the gas heat pump system, the control unit can remeasure the turbocharger pressure of the recirculated exhaust gas and determine whether the remeasured turbocharger pressure of the recirculated exhaust gas reaches the target turbocharger pressure. If it is determined that the remeasured turbocharger pressure of the recirculated exhaust gas is equal to or higher than the target turbocharger pressure, the control unit can maintain the target speed to which the speed of the turbocharger motor is increased.

[0032] If the gas heat pump system determines that the remeasured turbocharger pressure of the recirculated exhaust gas is lower than the target turbocharger pressure, the control system can increase the speed of the turbocharger motor to a speed obtained by adding the predetermined increase to the target speed.

[0033] In the gas heat pump system, the control unit can compare the measured concentration of pollutants with a first reference concentration and can determine whether its measured concentration exceeds the first reference concentration. If it is determined that its measured concentration is lower than the first reference concentration, the control unit can compare its measured concentration with a second reference concentration that is lower than the first reference concentration.

[0034] If it is determined in the gas heat pump system that its measurement concentration is equal to or higher than the second reference concentration, the control system can maintain the speed of the turbocharger motor and thereby ensure that the turbocharge quantity of the recirculated exhaust gas is maintained.

[0035] If it is determined in the gas heat pump system that its measurement concentration is lower than the second reference concentration, the control system can reduce the speed of the turbocharger motor and thereby lower the turbocharge quantity of the recirculated exhaust gas.

[0036] Furthermore, the gas heat pump system can include: an intake manifold that supplies a fuel-air mixture to the gas engine; an intake manifold pressure sensor that detects the pressure of the fuel-air mixture in the intake manifold; and a recirculation exhaust gas pressure sensor that detects the turbocharger pressure of the recirculated exhaust gas discharged from the exhaust gas turbocharger, wherein the control unit can receive a signal corresponding to the pressure of the fuel-air mixture from the intake manifold pressure sensor and can measure the pressure of the fuel-air mixture, and the control unit can receive a signal corresponding to the pressure of the recirculated exhaust gas from the recirculation exhaust gas pressure sensor and can measure the turbocharger pressure of the recirculated exhaust gas.

[0037] In the gas heat pump system, the control unit can calculate a pressure difference between the measured pressure of the fuel-air mixture and the measured turbocharger pressure of the recirculated exhaust gas, and can calculate a target turbocharger pressure of the recirculated exhaust gas.

[0038] In the gas heat pump system, the control unit can calculate the current speed of the turbocharger motor and can reduce the speed of the turbocharger motor to a target speed, which is obtained by subtracting a predetermined decrease from the calculated current speed.

[0039] In a gas heat pump system, the predetermined output speed can be 1,000 rpm.

[0040] In the gas heat pump system, the control unit can remeasure the turbocharger pressure of the recirculated exhaust gas and determine whether the remeasured turbocharger pressure of the recirculated exhaust gas reaches the target turbocharger pressure. If it is determined that the remeasured turbocharger pressure of the recirculated exhaust gas is lower than the target turbocharger pressure, the control unit can maintain the target speed to which the speed of the turbocharger motor is reduced.

[0041] If the gas heat pump system determines that the remeasured turbocharger pressure of the recirculated exhaust gas is equal to or higher than the target turbocharger pressure, the control system can reduce the speed of the turbocharger motor to a speed obtained by additionally subtracting the predetermined decrease from the target speed.

[0042] In the gas heat pump system as disclosed, the recirculated exhaust gas is supplied by means of the engine-driven turbocharger. This allows for the advantage of active control of the quantity and pressure of the recirculated exhaust gas flowing.

[0043] Furthermore, in the disclosed gas heat pump system, the concentration of pollutants contained in the exhaust gas is monitored in real time, and the amount of recirculated exhaust gas is adjusted based on the monitoring results. This allows for a significant reduction in the amount of pollutants produced and an improvement in the operating efficiency of the gas engine. Brief description of the drawings

[0044] These and other tasks, features, and other advantages of the disclosure will become clearer from the following detailed description in conjunction with the accompanying drawings. They show: Fig. 1 a schematic view of a configuration of a gas heat pump system according to an embodiment of the disclosure; Fig. 2 a view of a closer configuration of an internal combustion engine module in Fig. 1; Fig. 3 a functional block diagram of a configuration of a control system for the gas heat pump system according to the embodiment of the disclosure; and Fig. 4, Fig. 5, Fig. 6 to Fig. 7 Flowcharts of a method for controlling the gas heat pump system according to an embodiment of the disclosure. More detailed description of the invention

[0045] Exemplary embodiments of the disclosure are described in more detail below with reference to the accompanying drawings.

[0046] Various modifications can be made to the disclosure, resulting in different embodiments. The resulting specific embodiments are also described in more detail below with reference to the drawings. This description is not intended to limit the disclosure to these specific embodiments. All modifications, equivalents, and substitutions that are part of the technical concept of the disclosure should be considered to fall within the scope of protection of the disclosure.

[0047] The terms "first" and "second," etc., serve to describe different constituent elements, but should not be interpreted as imposing a restriction on these elements. These terms merely serve to distinguish one element from another. For example, a first constituent element can be expressed as a second constituent element without altering the scope of protection afforded by the disclosure. Likewise, the second constituent element can also be expressed as a first constituent element.

[0048] The phrase "and / or" is used to connect two words, clauses and sentences, or to refer to one of the two words, clauses and sentences.

[0049] It should be clear that when a component element is described as "coupled" or "connected" to another component element, this means that the component element can be directly coupled or directly connected to the other component element, or that an intervening component element may be present. Conversely, it should be clear that when a component element is described as "directly coupled" or "directly connected" to another component element, this means that no intervening component element is present.

[0050] The terms used in the application serve only to describe specific embodiments and are not intended to limit the disclosure. The indefinite article is used to denote "one or more" and not just "one", unless the context clearly requires otherwise.

[0051] In the application, the term "exhibit", "have", etc., should indicate that a characteristic, a number, a step, a process, a component element, a component or combinations thereof listed in the description are present, and is thus to be understood as not excluding from the outset the possibility that one or more other characteristics, numbers, steps, processes, components elements, or combinations thereof are present or added.

[0052] Unless otherwise specified, each term, including technical and scientific terms, used in the application has the same meaning that would normally be understood by a person skilled in the art in the field of technology to which the invention belongs. The term defined in commonly used dictionaries is to be understood as having the same meaning in the technical context, and unless expressly specified otherwise in the application, it is not to be interpreted with an ideal or overly formal meaning.

[0053] The embodiments are described below for illustrative purposes to assist the person skilled in the art in fully understanding the disclosure, and shapes, sizes, etc. of elements in the drawings may be exaggerated for clarity.

[0054] Fig. Figure 1 is a schematic view of a configuration of a gas heat pump system according to an embodiment of the disclosure. Fig. Figure 2 shows a closer view of the configuration of an internal combustion engine module in Fig. 1.

[0055] With reference to Fig. 1 A gas heat pump system according to an embodiment of the disclosure comprises a climate module, an internal combustion engine module and a cooling module.

[0056] The climate module has several components that are necessary for a refrigeration cycle.

[0057] For example, the climate control module has a compressor 110 and a four-way valve 115. The compressor 110 compresses refrigerant. The four-way valve 115 reverses the direction of the refrigerant compressed in the compressor 110.

[0058] The compressor 110 operates with a driving force generated by an internal combustion engine 201, which will be described later, and serves to compress the refrigerant in a gaseous state and to release the resulting refrigerant.

[0059] A disc clutch assembly 112 is provided on a drive shaft of the compressor 110. The drive force generated by the internal combustion engine 210 is transmitted to the compressor 110 via a belt 111 and the disc clutch assembly 112.

[0060] In Fig. Figure 1 shows a configuration in which the climate module has one compressor 110, but the climate module can have multiple compressors 110 depending on the load capacity of an indoor climate condenser unit.

[0061] The multiple compressors 110 each have the disc-clutch arrangement 112, to which the driving force generated by the internal combustion engine 210 is selectively transmitted.

[0062] Furthermore, the climate module can have an external heat exchanger 120 and an internal heat exchanger 140.

[0063] The outdoor heat exchanger 120 is arranged in an outdoor air conditioning condenser unit that is installed outdoors, and the indoor heat exchanger 140 is arranged in an indoor air conditioning condenser unit that is installed indoors.

[0064] The refrigerant passing through the four-way valve 115 flows to the outdoor heat exchanger 120 or to the indoor heat exchanger 140.

[0065] Components, with the exception of the internal heat exchanger 140 and an internal expansion device 145 of the gas heat pump system, which are located in Fig. The units shown in 1 are located outdoors, i.e., in the outdoor climate condenser unit.

[0066] In a case where the gas heating system is operating in a cooling mode, the refrigerant passing through the four-way valve 115 flows to the indoor heat exchanger 140 via the outdoor heat exchanger 120.

[0067] In contrast, when the gas heat pump system operates in a heating mode, the refrigerant passing through the four-way valve 115 flows to the outdoor heat exchanger 120 via the indoor heat exchanger 140.

[0068] Furthermore, the climate module can have a refrigerant pipe 170 (a flow path indicated by a solid line) that connects the compressor 110, the outdoor heat exchanger 120, the indoor heat exchanger 140, etc., and guides a flow of refrigerant.

[0069] First, the configuration of the gas heat pump system operating in cooling mode is described below.

[0070] The refrigerant flowing to the outdoor heat exchanger 120 exchanges heat with the outside air and is thereby condensed. An outdoor fan 122, which blows the outside air into the outdoor heat exchanger 120, is arranged on one side of it.

[0071] A main expansion device 125 for decompressing the refrigerant is provided at the outlet of the outdoor heat exchanger 120. For example, the main expansion device 125 can include an electronic expansion valve (EEV). The electronic expansion valve (EEV) is controlled by means of a pulse width modulation method. If a pulse increases (by a positive value), the degree to which the main expansion device 125 is open is increased. If the pulse decreases (by a negative value), the degree to which the main expansion device 125 is open is decreased.

[0072] When operating in cooling mode, the main expansion device 125 is fully open, thus no decompression of the refrigerant is carried out.

[0073] A subcooling heat exchanger 130 for additional cooling of the refrigerant is provided at the outlet side of the main expansion device 125. A subcooling flow path 132 is then connected to the subcooling heat exchanger 130. The subcooling flow path 132 branches off from a refrigerant pipe 170 and is connected to the subcooling heat exchanger 130.

[0074] A subcooling expansion device 135 is attached to the subcooling flow path 132. The refrigerant flowing along the subcooling flow path 132 is decompressed as it passes through the subcooling expansion device 135.

[0075] In the subcooling heat exchanger 130, heat exchange takes place between the refrigerant in the refrigerant pipe 170 and the refrigerant on the subcooling flow path 132. In a heat exchange process, the refrigerant in the refrigerant pipe 170 is subcooled, and the refrigerant on the subcooling flow path 132 absorbs heat.

[0076] The subcooling flow path 132 is connected to a gas-liquid separator 160. The refrigerant on the subcooling flow path 132, which exchanges heat in the subcooling heat exchanger 130, flows into the gas-liquid separator 160.

[0077] The refrigerant in the refrigerant pipe 170, which passes through the subcooling heat exchanger 130, flows to the indoor air conditioning condenser unit, is decompressed in the indoor expansion device 145, and then evaporates in the indoor heat exchanger 140. The indoor expansion device 145 is installed in the indoor air conditioning condenser unit and is configured as an electronic expansion valve (EEV).

[0078] Furthermore, the refrigerant evaporating in the internal heat exchanger 140 can pass through the four-way valve 115 and then flow directly into the gas-liquid separator 160. Gaseous refrigerant resulting from the refrigerant separation is absorbed in the compressor 110.

[0079] The following describes the configuration of the gas heat pump system operating in heating mode.

[0080] During a heating cycle, the refrigerant compressed in the compressor 110 flows to the internal heat exchanger 140, and the refrigerant condensed in the internal heat exchanger 140 flows to an auxiliary heat exchanger 150. A refrigerant branch pipe 151 is connected to the auxiliary heat exchanger 150.

[0081] An expansion valve 152 is provided on a section of the refrigerant branch pipe 151 positioned at the inlet side of the auxiliary heat exchanger 150. The expansion valve 152 decompresses the refrigerant while regulating the refrigerant flow.

[0082] The auxiliary heat exchanger 150 is a heat exchanger in which heat exchange takes place between low-pressure refrigerant and high-temperature cooling water. Plate heat exchangers are one example of the auxiliary heat exchanger 150.

[0083] The refrigerant passing through the auxiliary heat exchanger 150 can flow into the gas-liquid separator 160.

[0084] In the gas-liquid separator 160, the refrigerant passing through the auxiliary heat exchanger 150 is separated into gas and liquid. The resulting gaseous refrigerant is absorbed in the compressor 110.

[0085] The cooling module has a cooling water pipe 360 ​​(a flow path indicated by a dashed line) that directs a cooling water flow to cool the internal combustion engine 210, which will be described later.

[0086] A coolant pump 300, several flow switching units 310 and 320, and a radiator 330 are mounted on the coolant pipe 360. The coolant pump 300 generates a flow force of the coolant. The several flow switching units 310 and 320 reverse the flow direction of the coolant. The radiator 300 cools the coolant.

[0087] The multiple flow switching units 310 and 320 include a first flow switching unit 310 and a second flow switching unit 320. For example, the first flow switching unit 310 and the second flow switching unit 320 each have a three-way valve.

[0088] The cooler 330 is positioned on one side of the external heat exchanger 120. The cooling water in the cooler 330 exchanges heat with the outside air by driving the external fan 122 and is cooled during this heat exchange process.

[0089] When the cooling water pump 300 is driven, the cooling water passes through the combustion engine 210 and an exhaust gas heat exchanger 280 and flows selectively into the radiator 330 or the auxiliary heat exchanger 150 via the first flow switching unit 310 and the second flow switching unit 320.

[0090] The combustion engine module includes the combustion engine 210 and various components for supplying a fuel-air mixture to the combustion engine 210.

[0091] The combustion engine module includes a mixer 230, which is located on the inlet side of the combustion engine 210 and mixes air and gaseous fuel.

[0092] An air filter 220 and a zero-pressure regulator 240 are installed upstream of the mixer 230. The air filter 220 supplies the mixer 230 with purified air via an air pipe 220a. The zero-pressure regulator 240 supplies gaseous fuel at a predetermined pressure or below via a fuel pipe 200b.

[0093] The zero pressure regulator 240 is a device that uniformly adjusts the output pressure regardless of the magnitude of the input pressure of the gaseous fuel or a change in the flow rate and supplies the resulting gaseous fuel.

[0094] In the mixer 230, the air passing through the air filter 220 and the gaseous fuel supplied by the zero-pressure regulator 240 are mixed to create the fuel-air mixture. The resulting fuel-air mixture is supplied to the internal combustion engine 210 via a mixing device 200c.

[0095] Furthermore, the combustion engine module can include a turbocharger 250 and an adjustment unit 270, which are arranged between the mixer 230 and the combustion engine 210.

[0096] The turbocharger 250 exerts pressure on the fuel-air mixture to increase its density and feeds the resulting fuel-air mixture to the internal combustion engine 210. The turbocharger 250 serves to provide a higher output than in a naturally aspirated internal combustion engine.

[0097] According to Fig. 1 The turbocharger exerts 250 pressure on the fuel-air mixture that enters it via a turbocharger inlet pipe 253 (in Fig. 1) flows in after being generated as a result of the mixing of air and gaseous fuel by the mixer 230, and delivers the resulting fuel-air mixture to the internal combustion engine 210 via a turbocharger outlet pipe 255 (in Fig. 2) out.

[0098] For example, according to Fig. 2 of the turbochargers 250, a first turbocharger 251 and a second turbocharger 252. The first turbocharger 251 and the second turbocharger 252 exert pressure at a first level on the fuel-air mixture produced by the mixer 230 and supply the resulting fuel-air mixture directly to the internal combustion engine 210, or exert pressure at a second level on the fuel-air mixture to which the pressure at the first level is exerted, and supply the resulting fuel-air mixture to the internal combustion engine 210.

[0099] The first turbocharger 251 and the second turbocharger 252 have motors 251b and 252b respectively, and impellers 251a and 252a respectively. The motors 251b and 252b have the same shape and structure. The impellers 251a and 252a have the same shape and structure.

[0100] The Turbocharger 250 is configured to incorporate motors 251b and 252b with identical shape and structure, as well as impellers 251a and 252a with identical shape and structure. This gives the Turbocharger 250 the advantages of potential miniaturization and increased efficiency compared to a turbocharger configured with a single motor and impeller.

[0101] The first engine 251b and the second engine 252b are configured to be housed in the engine casing 254, which is shared by the first engine 251b and the second engine 252b, and are cooled by the fuel-air mixture flowing into the engine casing 254.

[0102] The first impeller 251a and the second impeller 252a are rotatably mounted in a first housing 251c and a second housing 252c respectively, each of which has a flow path for the fuel-air mixture.

[0103] The adjusting unit 270 is located between the turbocharger 250 and the internal combustion engine 210 and adjusts the amount of compressed fuel-air mixture to be supplied to the internal combustion engine 210.

[0104] Examples of the adjustment unit 270 include a valve that employs an electronic throttle control (ETC) approach. An embodiment in which the electronically controlled ETC valve is used as the adjustment unit 270 is described below. However, the disclosure is not limited to this embodiment.

[0105] In this way, the mixer 230 mixes gaseous fuel and air to create the fuel-air mixture. The turbocharger 250 exerts high pressure on the generated fuel-air mixture, after which the resulting fuel-air mixture is supplied to the internal combustion engine 210.

[0106] At this point, the quantity of the high-pressure fuel-air mixture to be supplied to the internal combustion engine 210 is precisely controlled by the ETC valve 270, thereby controlling the output of the internal combustion engine 210.

[0107] As previously described, the fuel-air mixture passing through the turbocharger 250 is in a state of high temperature and high pressure. For this reason, an intercooler 260 is provided between the turbocharger 250 and the control unit 270. The intercooler 260 reduces the temperature and pressure of the fuel-air mixture and supplies the resulting fuel-air mixture to a cylinder 211 of the internal combustion engine 210.

[0108] For example, the intercooler 260 is configured so that heat exchange occurs between the fuel-air mixture to be supplied to the internal combustion engine 210 and a portion of the cooling water flowing to the internal combustion engine 210, or so that it is configured according to Fig. 2. Heat exchange between the via a separate water pump 261 in Fig. 2 circulating coolant and the fuel-air mixture.

[0109] Furthermore, the combustion engine module can have the exhaust gas heat exchanger 280, which is located on the exhaust gas outlet side of the combustion engine 210 and in which heat exchange between the cooling water and exhaust gas occurs.

[0110] Fig. Figure 2 is a schematic view of a configuration of an internal combustion engine module 200 in Fig. 1. The following is based on Fig. 2 a more detailed configuration of the combustion engine module 200 according to an embodiment of the disclosure is described.

[0111] The combustion engine module 200 of the gas heat pump system according to the disclosure can further comprise an exhaust gas charger 290, which feeds at least a proportion of the exhaust gas emitted by the combustion engine 210 back to the combustion engine 210 as recirculated exhaust gas.

[0112] The exhaust gas supercharger 290 serves to exert pressure on at least a portion of the exhaust gas that is discharged to an exhaust pipe 200d via an exhaust manifold 213, and to supply the resulting portion of it as recirculated exhaust gas to an inlet manifold 212.

[0113] At this point, the turbocharging quantity of the recirculated exhaust gas is actively adjusted within a range of 3 to 30% of the total exhaust gas quantity.

[0114] To actively control the turbocharging quantity of the recirculated exhaust gas, the exhaust gas turbocharger 290 is motor-driven.

[0115] The exhaust gas turbocharger 290 has a turbocharger motor 291, the speed of which can be controlled according to a control signal from a control unit 300.

[0116] An output shaft of the turbocharger motor 291 is connected to a turbocharger impeller 292, thereby rotating the turbocharger impeller 292. The turbocharger impeller 292 exerts pressure on the recirculated exhaust gas, which is fed to it via an exhaust bypass pipe 200e, which will be described later, after which the resulting recirculated exhaust gas is fed to the inlet manifold 212 via an outlet pipe 293.

[0117] At this point, the turbocharging quantity of the recirculated exhaust gas, which is fed to the inlet manifold 212 via the exhaust gas turbocharger 290, is determined on the basis of a concentration of pollutants in the exhaust pipe 200d.

[0118] As is well known, pollutants normally contained in exhaust gases include carbon monoxide (CO) and nitrogen oxides (NOx). x ) and hydrocarbons (HC). According to the disclosure, the turbocharging quantity of the recirculated exhaust gas is controlled based on the concentration of at least one of these pollutants.

[0119] For this purpose, an exhaust gas sensor 258, which detects a concentration of pollutants contained in the exhaust gas, is provided on the exhaust pipe 200d.

[0120] The exhaust gas sensor 258 is designed to measure the concentration of pollutants contained in the exhaust gas that is ultimately released to the outside. For this reason, it is advantageous that the exhaust gas sensor 258 is located furthest downstream of the exhaust pipe 200d.

[0121] According to the disclosure, any exhaust gas sensor 258 can be provided without restriction, which is configured to measure the concentration of pollutants contained in the exhaust gas. The application of this modified example should fall within the scope of protection of the disclosure.

[0122] The exhaust gas bypass pipe 200e for directing the recirculated exhaust gas to the exhaust gas turbocharger 290 is provided in the form of a pipe that branches off from the exhaust pipe 200d.

[0123] In this case, it is advantageous that the exhaust gas bypass pipe 200e is positioned so that it branches off from the exhaust gas pipe 200d downstream of the exhaust gas heat exchanger 280.

[0124] The reason for this positioning is that the exhaust gas emitted from the exhaust manifold 213 normally has a temperature in the range of approximately 300 to 700 °C. If the exhaust gas is fed to the exhaust manifold 212 without cooling, the density of the fuel-air mixture is reduced, which has a negative impact on the efficiency of the internal combustion engine 210.

[0125] Therefore, the exhaust gas must be sufficiently cooled before being fed in. For this purpose, the exhaust gas bypass pipe 200e is positioned so that it branches off from the exhaust gas pipe 200d downstream of the exhaust gas heat exchanger 280 in such a way that the exhaust gas is fed in as recirculated exhaust gas, which is cooled to approximately 70 °C as it passes through the exhaust gas heat exchanger 280.

[0126] The turbocharger impeller 292 of the exhaust gas turbocharger 290 exerts pressure on the recirculated exhaust gas, which is fed to it via the exhaust gas bypass pipe 200e, after which the resulting recirculated exhaust gas flows into the inlet manifold 212 via the outlet pipe 293, which connects an outlet of the exhaust gas turbocharger 290 and the inlet manifold 212.

[0127] Additionally, a recirculation exhaust gas pressure sensor 257 is attached to the outlet pipe 293. The recirculation exhaust gas pressure sensor 257 detects in real time the pressure of the recirculated exhaust gas that is discharged from the exhaust gas turbocharger 290 and fed to the intake manifold 212.

[0128] Furthermore, an intake manifold pressure sensor 256, normally known as a MAP sensor, is attached to the intake manifold 212. The intake manifold pressure sensor 256 detects in real time the pressure of the fuel-air mixture supplied to cylinder 211 of the internal combustion engine 210.

[0129] As disclosed, a configuration is used in which the turbocharging quantity of the recirculated exhaust gas is controlled without a separate valve component. Therefore, the turbocharging quantity of the recirculated exhaust gas, which is supplied via the exhaust gas turbocharger 290, is controlled by a pressure differential as a variable between the turbocharger pressure detected by the recirculated exhaust gas pressure sensor 257 and the pressure of the fuel-air mixture detected by the intake manifold pressure sensor 256.

[0130] This means that, as described later, in a case where the turbocharger charge of the recirculated exhaust gas needs to be increased, the turbocharger charge of the recirculated exhaust gas is controlled by increasing the speed of the turbocharger motor 291 of the exhaust gas turbocharger 290, thereby increasing the pressure differential. Conversely, in a case where the turbocharger charge of the recirculated exhaust gas needs to be decreased, the turbocharger charge of the recirculated exhaust gas is controlled by decreasing the speed of the turbocharger motor 291 of the exhaust gas turbocharger 290, thereby lowering the pressure differential.

[0131] The following are based on Fig. 4, Fig. 5, Fig. 6 to Fig. 7 describes a specific tax procedure and a specific configuration.

[0132] Fig. Figure 3 is a functional block diagram of a configuration of the control unit 300 of the gas heat pump system according to the embodiment of the disclosure. Fig. 4, Fig. 5, Fig. 6 to Fig. 7 are flowcharts of a method for controlling the gas heat pump system according to an embodiment of the disclosure.

[0133] The following describes the procedure for controlling the gas heat pump system as disclosed, with a focus on the control unit 300.

[0134] As shown, the control unit 300 is electrically connected to the climate module, the cooling module, a power supply unit 400 and the combustion engine module 200 and generates signals to control these components.

[0135] If, in a state where the gas heat pump system is stopped, a system operating signal is first entered via an operating unit (not shown), the control unit 300 generates signals to operate the climate module, the cooling module and the combustion engine module 200, receives the necessary electrical current from the power supply unit 400 and supplies the received electrical current to the climate module, the cooling module and the combustion engine module 200.

[0136] A specific procedure and configuration for how the 300 controller controls the climate module and the cooling module are known in the technology, which is why their more detailed descriptions are omitted.

[0137] An operating condition for operating the combustion engine module 200 is read from a memory 310. In particular, a control is carried out such that the air pipe 200a and the fuel pipe 200b, which were described previously, are open and that air and fuel are thus introduced from the air pipe 200a and fuel pipe 200b respectively and mixed in the mixer 230.

[0138] In addition to driving the turbocharger 250, the control unit 300 also supplies electrical current to the first motor 251b and the second motor 252b. In this case, the control unit 300 operates the first motor 251b and the second motor 252b independently of each other.

[0139] When the fuel-air mixture, on which pressure is applied, is supplied to the internal combustion engine 210, the control unit 300 sends an ignition signal to a spark plug in accordance with a stroke of each cylinder 211 and ignites the fuel-air mixture supplied to each cylinder 211.

[0140] The control unit 300 adjusts the electrical current supplied to the turbocharger motor 291 of the exhaust gas turbocharger 290 and thereby controls the speed of the turbocharger motor 291. As will be described later, the control unit 300 controls the speed of the turbocharger motor 291 in such a way that it increases or decreases it according to the concentration of pollutants contained in the exhaust gas.

[0141] In addition, the control unit 300 is electrically connected to the intake manifold pressure sensor 256, the recirculation exhaust gas pressure sensor 257 and the exhaust gas sensor 258 and monitors in real time the pressure of the fuel-air mixture, the turbocharger pressure of the recirculation exhaust gas, the concentration of pollutants contained in the exhaust gas, etc. via electrical signals that it receives from these components.

[0142] Furthermore, the control unit 300 is electrically connected to an actuator of the ETC valve 270. If the output of the internal combustion engine 210 is increased or decreased, the actuator adjusts the degree to which the ETC valve 270 is open according to a control signal from the control unit 300, thereby increasing or decreasing the output of the internal combustion engine 210.

[0143] The following describes a specific process for controlling the combustion engine module 200 according to a required load ratio of the climate module.

[0144] First, the control unit 300 receives a signal from the exhaust gas sensor 258 corresponding to the concentration of pollutants and measures the concentration of pollutants (S1).

[0145] The pollutants include carbon monoxide, nitrogen oxides, and / or hydrocarbons. The exhaust gas sensor 258 generates an electrical signal corresponding to the concentration of these substances and transmits this signal to the control unit 300. The control unit 300 measures the pollutant concentration based on the transmitted electrical signal.

[0146] Next, the controller 300 compares a measurement concentration Cm with a preset first reference concentration Cth1 (S2).

[0147] The first reference concentration Cth1 is ensured by retrieving data that was previously stored in the aforementioned memory 310. The first reference concentration Cth1 represents a numerical value above which the concentration of pollutants contained in the exhaust gas falls out of an acceptable range and serves as a reference variable above which control measures to reduce exhaust emission levels must be implemented.

[0148] The controller 300 then determines whether the measurement concentration Cm exceeds the first reference concentration Cth1 (S3).

[0149] If it is determined that the measurement concentration Cm is equal to or higher than the first reference concentration Cth1, the control unit 300 increases the speed of the turbocharger motor 291 of the exhaust gas turbocharger 290 and thereby increases the turbocharge quantity of the recirculated exhaust gas (S4).

[0150] In particular, according to Fig. 5 To increase the turbocharge quantity of the recirculated exhaust gas, the control unit 300 first receives a signal corresponding to the pressure of the fuel-air mixture from the intake manifold pressure sensor 256 and measures the pressure P1 of the fuel-air mixture (S41).

[0151] Subsequently, the control unit 300 receives a signal corresponding to the pressure of the recirculated exhaust gas from the recirculated exhaust gas pressure sensor 257 and measures the turbocharger pressure P2 of the recirculated exhaust gas supplied by the intake manifold 212 (S42).

[0152] The control unit 300 calculates a pressure difference (ΔP = P2 - P1), which corresponds to a difference in value between the measured pressure P1 of the fuel-air mixture and the turbocharger pressure P2, and calculates a target turbocharger pressure P2_t to increase the turbocharge quantity of the recirculated exhaust gas (S43).

[0153] Here, the target turbocharger pressure P2_t is calculated as a value obtained by adding a predetermined pressure increase to a calculated pressure difference (ΔP). The predetermined pressure increase is advantageously 50 hPa.

[0154] Once the pressure difference and the target turbocharger pressure P2_t have been calculated, the control unit 300 calculates a current speed M_c of the turbocharger motor 291 of the exhaust gas turbocharger 290 (S44).

[0155] Any device known in engineering can be used to calculate the rotational speed of the turbocharger motor 291. Advantageously, the rotational speed of the turbocharger motor 291 is calculated in a way that does not use a sensor.

[0156] Once the current speed M_c of the turbocharger motor 291 has been calculated, the controller 300 increases the speed of the turbocharger motor 291 to a target speed, which is obtained by adding a predetermined increase to the calculated current speed M_c (S45).

[0157] Advantageously, the predetermined increase is 1,000 rpm.

[0158] Once the speed of the turbocharger motor 291 is fully increased, the control unit 300 again measures the turbocharger pressure P2 of the recirculated exhaust gas via the recirculated exhaust gas pressure sensor 257 (S46).

[0159] Control unit 300 determines whether the remeasured turbocharger pressure P2 reaches the target turbocharger pressure (S47).

[0160] If it is determined that the remeasured turbocharger pressure P2 is equal to or higher than the target turbocharger pressure P2_t, the target speed is maintained, to which the speed of the turbocharger motor 291 is increased.

[0161] In a state where the target speed is maintained, to which the speed of the turbocharger motor 291 is increased, and thereby the turbocharge quantity of the recirculated exhaust gas is increased, the control unit 300 returns to step S1 and measures the concentration of pollutants again.

[0162] If, in step S47, it is determined that the remeasured turbocharger pressure P2 is lower than the target turbocharger pressure P2_t, the control unit 300 determines whether a predetermined time interval (Δt) has elapsed after step S45 has been performed (S49a).

[0163] Advantageously, the predetermined time interval (Δt) is five seconds.

[0164] If it is determined that the predetermined time interval (Δt) has not elapsed, the control unit 300 returns to steps S46 and S47 and determines again whether the target turbocharger pressure has been reached.

[0165] When it is determined that the predetermined time interval (Δt) has elapsed, the current rotational speed is reset (S49b).

[0166] Next, the controller 300 returns to step S45 and controls the speed of the turbocharger motor 291 to be additionally increased to a speed obtained by adding a predetermined increase to a speed to which the current speed is reset.

[0167] If in step S3 it is determined that the measurement concentration Cm is lower than the first reference concentration Cth1, the controller 300 compares the measurement concentration Cm with a second reference concentration Cth2 and determines whether the measurement concentration Cm exceeds the second reference concentration Cth2 (S5 and S6).

[0168] Here, the second reference concentration Cth2 corresponds to a value that is smaller than the first reference concentration Cth1 and serves as a basis for determining whether the turbocharging quantity of the recirculated exhaust gas is maintained or reduced.

[0169] This means that, if the concentration of pollutants in the exhaust gas currently being emitted is equal to the second reference concentration Cth2, it has a numerical value at or below which exhaust emissions are not subject to any legal regulations. Therefore, the turbocharger charge of recirculated exhaust gas supplied to the combustion engine 210 can be reduced, and the turbocharged engine 291 can operate at a lower speed, thus reducing power consumption.

[0170] Like the first reference concentration Cth1, the second reference concentration Cth2 is ensured by reading data that is previously stored in the aforementioned memory 310.

[0171] If in step S6 it is determined that the measurement concentration Cm is equal to or higher than the second reference concentration Cth2, the control unit 300 controls the turbocharger motor 291 so that a current rotational speed is maintained (S7).

[0172] This means that the control is carried out in such a way that the turbocharging quantity of the recirculated exhaust gas supplied by the exhaust gas turbocharger 290 is kept at an up-to-date level.

[0173] To comply Fig. 7 In particular to maintain the turbocharge quantity of the recirculated exhaust gas, the control unit 300 first receives the signal corresponding to the pressure of the fuel-air mixture from the intake manifold pressure sensor 256 and measures the pressure P1 of the fuel-air mixture (S71).

[0174] The control unit 300 then receives a signal corresponding to the pressure of the recirculated exhaust gas from the recirculated exhaust gas pressure sensor 257 and measures the turbocharger pressure P2 of the recirculated exhaust gas supplied by the intake manifold 212 (S42).

[0175] The control unit 300 calculates the pressure difference (ΔP = P2 - P1), which corresponds to the difference in value between the measured pressure P1 of the fuel-air mixture and the measured turbocharger pressure P2 (S73).

[0176] Once the pressure difference is calculated, the control unit 300 calculates the current speed M_c of the turbocharger motor 291 of the exhaust gas turbocharger 290 (S74).

[0177] As previously described, any device known in engineering can be used to calculate the rotational speed of the turbocharger motor 291. Advantageously, the rotational speed of the turbocharger motor 291 is calculated in a way that does not use a sensor.

[0178] Once the current rotational speed M_c of the turbocharger motor 291 has been calculated, the control unit 300 determines whether the calculated pressure difference (ΔP) has a numerical value of 0 or less (S75).

[0179] That the pressure difference (ΔP) has a value of 0 or below indicates a condition in which the turbocharger pressure P2 is lower than the pressure P1 of the fuel-air mixture, i.e., that the fuel-air mixture flows back to the exhaust turbocharger 290.

[0180] Therefore, if in step S75 it is determined that the calculated pressure difference (ΔP) has a numerical value greater than 0, the control unit 300 determines that the operation is in a normal state and controls the turbocharger motor 291 to operate at the current speed M_c (S76).

[0181] If in step S75 it is determined that the calculated pressure difference ΔP has a numerical value of 0 or less, the control 300 increases the speed of the turbocharger motor 291 to a target speed to increase the turbocharger pressure P2, which is obtained by adding a predetermined increase to the current speed M_c of the turbocharger motor 291 (S77).

[0182] In this case, the predetermined increase is advantageously 500 rpm.

[0183] The controller 300 then determines whether the predetermined time interval (Δt) has elapsed since the point at which the speed of the turbocharger motor 291 is increased (S78). (S78)

[0184] Advantageously, the predetermined time interval (Δt) is five seconds.

[0185] If it is determined that the predetermined time interval (Δt) has not elapsed, the controller 300 returns to step S75 and determines the pressure difference (ΔP) again.

[0186] When it is determined that the predetermined time interval (Δt) has elapsed, the controller 300 returns to step S71 and performs step S71 and the subsequent steps again.

[0187] If in step S6 it is determined that the measurement concentration Cm is lower than the second reference concentration (Cth2), the control unit 300 reduces the speed of the turbocharger motor 291 of the exhaust gas turbocharger 290 and thus reduces the turbocharge quantity of the recirculated exhaust gas (S8).

[0188] In particular, according to Fig.7 To reduce the turbocharge quantity of the recirculated exhaust gas, the control unit 300 first receives the signal corresponding to the pressure of the fuel-air mixture from the intake manifold pressure sensor 256 and measures the pressure P1 of the fuel-air mixture (S81).

[0189] Next, the control unit 300 receives the signal corresponding to the pressure of the recirculated exhaust gas from the recirculated exhaust gas pressure sensor 257 and measures the turbocharger pressure P2 of the recirculated exhaust gas supplied by the intake manifold 212 (S82).

[0190] The control unit 300 calculates a pressure difference (ΔP = P2 - P1), which corresponds to a difference in value between the measured pressure P1 of the fuel-air mixture and the turbocharger pressure P2, and calculates the target turbocharger pressure P2_t to reduce the turbocharge quantity of the recirculated exhaust gas (S83).

[0191] Here, the target turbocharger pressure P2_t is calculated as a value obtained by subtracting a predetermined pressure drop from the calculated pressure difference (ΔP). The predetermined pressure drop is advantageously 50 hPa.

[0192] Once the pressure difference and the target turbocharger pressure P2_t have been calculated, the control unit 300 calculates the current speed M_c of the turbocharger motor 291 of the exhaust gas turbocharger 290 (S84).

[0193] As previously described, any device known in engineering can be used to calculate the rotational speed of the turbocharger motor 291. Advantageously, the rotational speed of the turbocharger motor 291 is calculated in a way that does not use a sensor.

[0194] Once the current speed M_c of the turbocharger motor 291 has been calculated, the controller 300 reduces the speed of the turbocharger motor 291 to a target speed, which is obtained by subtracting a predetermined decrease from the calculated current speed M_c (S85).

[0195] Advantageously, the predetermined decrease speed is 1,000 rpm.

[0196] If the speed of the turbocharger motor 291 is completely reduced, the control unit 300 again measures the turbocharger pressure P2 of the recirculated exhaust gas via the recirculated exhaust gas pressure sensor 257 (S86).

[0197] Control unit 300 determines whether the remeasured turbocharger pressure P2 reaches the target turbocharger pressure (S87).

[0198] If it is determined that the remeasured turbocharger pressure P2 is lower than the target turbocharger pressure P2_t, the target speed is maintained, to which the speed of the turbocharger motor 291 is reduced (S48).

[0199] In a state where the target speed is maintained, to which the speed of the turbocharger motor 291 is reduced, and thereby the turbocharge quantity of the recirculated exhaust gas is increased, the control unit 300 returns to step S1 and measures the concentration of pollutants again.

[0200] If in step S87 it is determined that the remeasured turbocharger pressure P2 is equal to or higher than the target turbocharger pressure P2_t, the control unit 300 determines whether the predetermined time interval (Δt) has elapsed after step S85 has been performed (89a).

[0201] Advantageously, the predetermined time interval (Δt) is five seconds.

[0202] If it is determined that the predetermined time interval (Δt) has not elapsed, the controller 300 returns to steps S86 and S87 and determines again whether the target turbocharger pressure has been reached.

[0203] When it is determined that the predetermined time interval (Δt) has elapsed, the current rotational speed is reset (S89b).

[0204] Next, the controller 300 returns to step S85 and controls the speed of the turbocharger motor 291 to be further reduced to a speed obtained by additionally subtracting a predetermined decrease from a speed from which the current speed is reset.

Claims

[1] Gas heat pump system which features: a compressor of an air conditioning module; a gas engine that generates a driving force for the compressor; an exhaust gas turbocharger that feeds at least a proportion of exhaust gas emitted from the gas engine back to the gas engine as recirculated exhaust gas; and an exhaust gas sensor configured to detect the concentration of pollutants contained in the exhaust gas; and a control unit that controls the operation of the exhaust gas turbocharger, the exhaust gas turbocharger features: a turbocharger impeller that exerts pressure on the recirculated exhaust gas and feeds the resulting recirculated exhaust gas to the gas engine; and a turbocharger motor that rotates the turbocharger impeller, and the control system is adjusted to increase the speed of the turbocharger motor, when the measured concentration is equal to or higher than a first reference concentration. [2] Gas heat pump system according to claim 1, further comprising: an exhaust pipe through which the exhaust gas from the gas heat pump system is released to the outside; the exhaust gas sensor, which is attached to the exhaust pipe; and an exhaust bypass pipe branching off upstream from the exhaust pipe from a position where the exhaust gas sensor is located, wherein the exhaust bypass pipe is configured to direct the recirculated exhaust gas to the exhaust gas turbocharger, the control system receives a signal from the exhaust gas corresponding to the concentration of pollutants and measures the concentration of pollutants. [3] Gas heat pump system according to claim 2, wherein the pollutants are carbon monoxide, nitrogen oxide and / or hydrocarbons. [4] Gas heat pump system according to claim 2 or 3, wherein the control compares the measurement concentration with the first reference concentration and determines whether the measurement concentration exceeds the first reference concentration, and if the measurement concentration is equal to or higher than the first reference concentration, the control increases the speed of the turbocharger motor and thereby increases the turbocharge quantity of the recirculated exhaust gas. [5] Gas heat pump system according to claim 4, further comprising: an intake manifold that supplies a fuel-air mixture to the gas engine; an intake manifold pressure sensor that detects the pressure of the fuel-air mixture in the intake manifold; and a recirculation exhaust gas pressure sensor that detects the turbocharger pressure of the recirculation exhaust gas released from the exhaust gas turbocharger, wherein the control unit receives a signal corresponding to the pressure of the fuel-air mixture from the intake manifold pressure sensor and measures the pressure of the fuel-air mixture and The control unit receives a signal from the recirculation exhaust pressure sensor corresponding to the pressure of the recirculation exhaust gas and measures the turbocharger pressure of the recirculation exhaust gas that is fed to the intake manifold. [6] Gas heat pump system according to claim 5, wherein the control system calculates a pressure difference between the measuring pressure of the fuel-air mixture and the measuring turbocharger pressure of the recirculated exhaust gas and calculates a target turbocharger pressure of the recirculated exhaust gas. [7] Gas heat pump system according to claim 6, wherein the control calculates a current speed of the turbocharger motor and increases the speed of the turbocharger motor to a target speed obtained by adding a predetermined increase to the calculated current speed. [8] Gas heat pump system according to claim 7, wherein the predetermined increase is 1,000 rpm. [9] Gas heat pump system according to claim 7 or 8, wherein the control system remeasures the turbocharger pressure of the recirculated exhaust gas via the recirculated exhaust gas and determines whether the remeasured turbocharger pressure of the recirculated exhaust gas reaches the target turbocharger pressure, and if it is determined that the remeasured turbocharger pressure of the recirculated exhaust gas is equal to or higher than the target turbocharger pressure, the control system maintains the target speed to which the speed of the turbocharger motor is increased. [10] Gas heat pump system according to claim 9, wherein, upon determination that the remeasured turbocharger pressure of the recirculated exhaust gas is lower than the target turbocharger pressure, the control increases the speed of the turbocharger motor to a speed obtained by adding the predetermined increase to the target speed. [11] Gas heat pump system according to claim 2, wherein the controller compares the measured concentration of the pollutants with a first reference concentration and determines whether its measured concentration exceeds the first reference concentration, and if it is determined that its measured concentration is lower than the first reference concentration, the controller compares its measured concentration with a second reference concentration which is lower than the first reference concentration. [12] Gas heat pump system according to claim 11, wherein, when determining that its measurement concentration is equal to or higher than the second reference concentration, the control maintains the speed of the turbocharger motor and thereby causes the turbocharge quantity of the recirculated exhaust gas to be maintained. [13] Gas heat pump system according to claim 11, wherein, when it is determined that its measurement concentration is lower than the second reference concentration, the control reduces the speed of the turbocharger motor and thereby reduces the turbocharge quantity of the recirculated exhaust gas. [14] Gas heat pump system according to claim 13, further comprising: an intake manifold that supplies a fuel-air mixture to the gas engine; an intake manifold pressure sensor that detects the pressure of the fuel-air mixture in the intake manifold; and a recirculation exhaust gas pressure sensor that detects the turbocharger pressure of the recirculated exhaust gas released from the exhaust gas turbocharger, wherein the control unit receives a signal corresponding to the pressure of the fuel-air mixture from the intake manifold pressure sensor and measures the pressure of the fuel-air mixture and The control unit receives a signal from the recirculation exhaust pressure sensor corresponding to the pressure of the recirculation exhaust gas and measures the turbocharger pressure of the recirculation exhaust gas. [15] Gas heat pump system according to claim 14, wherein the control system calculates a pressure difference between the measuring pressure of the fuel-air mixture and the measuring turbocharger pressure of the recirculated exhaust gas and calculates a target turbocharger pressure of the recirculated exhaust gas. [16] Gas heat pump system according to claim 15, wherein the control calculates an actual speed of the turbocharger motor and reduces the speed of the turbocharger motor to a target speed obtained by subtracting a predetermined decrease from the calculated actual speed. [17] Gas heat pump system according to claim 16, wherein the predetermined take-off speed is 1,000 rpm. [18] Gas heat pump system according to claim 16, wherein the control system remeasures the turbocharger pressure of the recirculated exhaust gas via the recirculated exhaust gas and determines whether the remeasured turbocharger pressure of the recirculated exhaust gas reaches the target turbocharger pressure, and if it determines that the remeasured turbocharger pressure of the recirculated exhaust gas is lower than the target turbocharger pressure, the control system maintains the target speed to which the speed of the turbocharger motor is reduced. [19] Gas heat pump system according to claim 18, wherein, when it is determined that the remeasured turbocharger pressure of the recirculated exhaust gas is equal to or higher than the target turbocharger pressure, the control reduces the speed of the turbocharger motor to a speed obtained by additionally subtracting the predetermined decrease from the target speed.

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