Gas engine heating and cooling unit

Abstract

PURPOSE: To increase the rotating / reversing efficiency of a second fan 64 of a gas engine air conditioner that uses a compact gas engine and a DC power generator to place an air conditioner in efficient operation.CONSTITUTION: A gas engine air conditioner comprises a comprehensive housing 9 having: a gas engine 1, a first cooling water circulation flow passage 51, and a second cooling water circulation flow passage 52; a first radiator 61; a second radiator 62; a channel changeover valve 53; a gas engine 1; a DC power generator 2; a motor 3; a compressor 41; a condenser 42; and a first fan 63 which rotates only normally; and a second fan 64 which rotates normally and reversely. The second fan 64 can rotate normally and reversely in an air conditioning state and an overheating state, and both ends of blades of the second fan 64 are bent at the same angle α while making an attack angle α+β of the normal / reverse rotation identical.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a gas engine air conditioner that uses a small gas engine and a DC generator to efficiently operate the air conditioner. [Background technology]

[0002] In recent years, systems that use gas engines to operate air conditioners have become increasingly common. Air conditioners that use heat pumps are also on the rise. Air conditioners have a compressor in the refrigerant circuit. A gas engine drives this compressor. Such systems are called gas engine heat pumps. This type of air conditioner has the advantage of being low-cost to operate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-257102 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-4332 Summary of the Invention [Problem to be solved by the invention]

[0004] In air conditioning and heating systems that run on gas heat pumps using gas engines, there are many configurations in which the gas engine and compressor are directly connected to drive the compressor. This configuration also includes the following types. First, there is a configuration in which the drive shaft of the gas engine is directly connected to the rotating shaft of the compressor. Second, there is a configuration in which rotation is transmitted between the gas engine and compressor via a belt. Third, there is a configuration in which rotation is transmitted between the gas engine and compressor via a chain.

[0005] These systems either directly connect the gas engine to the compressor or use a belt or chain. In either case, the rotation of the gas engine is directly transmitted to the compressor, giving the compressor more power than necessary. Most of the power given to the compressor is too much for the heating and cooling system, resulting in wasted power. Furthermore, the vibrations from the gas engine when it is running can be transmitted to the compressor, placing excessive strain on it. Furthermore, torque fluctuations during operation of the gas engine can also cause the compressor to operate unstably.

[0006] Furthermore, if rotation is transmitted by a belt or chain between the gas engine and the compressor, it may be necessary to adjust the tension of the belt or chain appropriately, and space for the belt or chain may be required on the gas engine, which will have a significant impact on management costs.

[0007] Furthermore, in air conditioning systems powered by gas heat pumps using gas engines, the heat from the gas engine and generator can easily cause the center of the housing housing the equipment to become extremely hot, and during heating, the refrigerant temperature at the condenser (heat exchanger) inlet can become too low. This makes it extremely difficult to control the temperature of the refrigerant used for heating and cooling. Furthermore, when overheating occurs, the center of the housing housing the equipment can easily become extremely hot, so an efficient airflow configuration is also required through the use of a devised fan structure.

[0008] The problem (technical problem or purpose, etc.) that this invention aims to solve is to eliminate the inconvenience caused by directly connecting the rotation transmission mechanism of the gas engine and compressor as described above, and to further improve the operating efficiency of heating and cooling systems operated by gas heat pumps using gas engines, while also requiring an innovative fan structure inside the casing to prevent overheating. [Means for solving the problem]

[0009] Therefore, the inventors have conducted extensive research to solve the above problems, and as a result, have found that the invention of claim 1 is a gas engine heating and cooling device comprising a comprehensive housing having a gas engine, a first cooling water circulation flow path and a second cooling water circulation flow path through which cooling water of the gas engine circulates, a first radiator provided in the first cooling water circulation flow path, a second radiator provided in the second cooling water circulation flow path, a water path switching valve for circulating cooling water to either the first cooling water circulation flow path or the second cooling water circulation flow path, a DC generator driven by the gas engine, a motor operated by the DC generator, a compressor driven by the motor and compressing a refrigerant, a condenser for heat exchange with the refrigerant, a first fan that rotates only in the forward direction to provide airflow to the first radiator, and a second fan that rotates in the forward and reverse directions to also provide airflow to the second radiator, The above-mentioned problems were solved by a gas engine air conditioning system characterized in that the first fan rotating in the forward direction and the second fan rotating in the reverse direction cause passing air to flow in one direction from the first radiator side to the second radiator side, and in the event of overheating, the water channel switching valve is configured to cause cooling water to flow into the second cooling water circulation flow path, and the first fan rotating in the forward direction and the second fan rotating in the forward direction are configured to introduce passing air into the overall housing to ventilate, the second fan has a plurality of blades, each of which has a flat blade center portion midway along the direction of rotation and has blade tips on both ends of the blade center portion in the rotation direction, and the blade centers of the second fan have an angle of attack of α+β in the forward and reverse rotations, while both of the blade tips are bent at the same angle α, and the second fan can ensure the same air volume in both the forward and reverse rotations.

[0010] The invention of claim 2 solves the above problem by providing the gas engine air conditioning and heating system of claim 1, wherein the number of blades of the second fan is four. The invention of claim 3 solves the above problem by providing the gas engine air conditioning and heating system of claim 1, wherein the number of blades of the second fan is three. The invention of claim 4 solves the above problem by providing the gas engine air conditioning and heating system of claim 1 or 2, wherein the angle of attack of the blades of the second fan, α+β, is 30 degrees, and α is 25 degrees. [Effects of the Invention]

[0011] In the invention of claim 1, the gas engine does not directly drive the compressor, but the TCU (total control unit) adjusts the excitation current to increase or decrease the generator's power, and supplies that power to the DC motor that drives the compressor, so that during heating, the heated air is used to heat the heat exchanger of the indoor unit. Therefore, in a system where the gas engine directly drives the compressor, the compressor has excess capacity beyond the heat exchange capacity (kW) of the indoor unit, resulting in wasted power. This can be avoided.

[0012] In addition, using a gas engine to drive multiple compressors with belts or chains results in a lot of wasted power transmission and space, and also transmits adverse effects such as vibration, but this eliminates these inconveniences.Furthermore, because the compressors are not driven directly by the gas engine, there is no need to worry about vibration caused by interference between the torque fluctuations of the gas engine and the cogging of the compressor (the awkward clicking motion that accompanies compression).

[0013] In the present invention of claim 1, in the event of overheating, the first fan and the second fan are used to introduce ventilation air into the overall housing for ventilation, while the second fan is rotated in the forward direction, and the angle of attack α+β of the second fan in the forward and reverse rotations is made the same, and both ends of the blades are bent at the same angle α, thereby making it possible to improve the air blowing efficiency of the second fan in the forward and reverse rotations, which is particularly effective in avoiding overheating or a state similar to it during high temperatures in summer, and reliably preventing overheating.

[0014] The inventions of claims 2 and 3 provide the same effect whether the blades are four or three. Furthermore, the invention of claim 4 has the advantage that, by making the second fan angle of attack α+β the same at 30 degrees and bending both ends of the blades at the same angle α at 25 degrees, it is possible to inexpensively and simply produce a gas engine air conditioning / heating system equipped with a fan that can rotate in both forward and reverse directions with particularly high efficiency. [Brief explanation of the drawings]

[0015] [Figure 1] 1A is a system diagram of a gas engine air conditioner according to the present invention, and FIG. 1B is a schematic diagram showing the configuration of output control from a DC generator to a DC motor by the controller of FIG. 1A. [Figure 2] 1 is a system diagram showing the overall operating state of a gas engine heating and cooling device according to the present invention during heating. [Figure 3] FIG. 3 is an operational diagram showing the flow of refrigerant during heating in the gas engine cooling and heating device of the present invention. [Figure 4] 4 is an operational diagram showing the direction of airflow from the first fan on the compressor unit side to the first radiator and condenser during heating in the gas engine air conditioner of the present invention. FIG. [Figure 5] 1 is a system diagram showing the overall operating state of a gas engine air conditioner according to the present invention during cooling. [Figure 6] FIG. 3 is an operational diagram showing the flow of refrigerant during cooling in the gas engine air conditioning device of the present invention. [Figure 7]4 is an operational diagram showing the direction of airflow from the first fan on the compressor unit side to the first radiator and condenser during cooling in the gas engine air conditioner of the present invention. FIG. [Figure 8] 10A, 10B, and 10C are diagrams showing a configuration in which a general housing that houses a power unit and a compressor unit is cooled by a first fan and a second fan. [Figure 9] (A) is a front view of the second fan that rotates forward and backward, (B) is a side view of the second fan, (C) is a cross-sectional view taken along the X1-X1 arrow in (A), (D) is an enlarged view of the blade portion in (C), and (E) is a perspective view of a partial cross-section of the blade portion of the fan. [Figure 10] (A) is a front view of another embodiment of a second fan that rotates forward and backward, (B) is a side view of the second fan, (C) is an enlarged cross-sectional view of the blade portion of (B), and (D) is a cross-sectional view of the central essential portion where the second fan is attached to the motor. [Figure 11] (A) is a cross-sectional view and a perspective view taken along the Y1-Y1 arrow in Figure 10(A), (B) is a perspective view of Figure 10(A), (C) is a cross-sectional view of one blade in (B), and (D) is a front view of yet another embodiment of the second fan. [Figure 12] FIG. 1 is a system diagram of a gas engine air conditioner according to the present invention, in which the power unit and compressor unit are housed in separate housings. [Figure 13] FIG. 1 is a system diagram of a gas engine air conditioning system according to the present invention, in which a plurality of compressor units are arranged in parallel with respect to one power unit. [Figure 14] (A) is a partially cross-sectional side view of the coupling, flywheel, and DC generator separated, (B) is a longitudinal side view of the coupling, (C) is a front view of the coupling, and (D) is a cross-sectional view taken along the Y1-Y1 arrow in (B). [Figure 15] 1 is a schematic diagram showing the configuration of a gas engine. [Figure 16] 1A is a side view with a portion cut away of the main refrigerant passage switching valve and the sub refrigerant passage switching valve, and FIG. 1B is a cross-sectional plan view of FIG. [Figure 17]1A to 1C are diagrams illustrating the configuration of a DC motor and a controller. [Figure 18] (A) is a system diagram of an embodiment of a gas engine heating and cooling system that uses an AC generator and an AC motor, and (B) is a schematic diagram showing the configuration of output control from the AC generator to the AC motor by the controller of (A). [Figure 19] FIG. 1 is a system overview diagram showing an operating state during heating in an embodiment using an AC generator and an AC motor. [Figure 20] FIG. 1A is a diagram showing a configuration for controlling an AC generator and an AC motor, and FIG. 1B is a detailed view of part (α) in FIG. [Figure 21] (A) is a system diagram of an embodiment of a gas engine heating and cooling system that uses an AC generator and a DC motor, and (B) is a schematic diagram showing the configuration of output control from the AC generator to the DC motor by the controller of (A). DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The present invention is mainly composed of a power unit A1 and a compressor unit A2, to which an indoor unit is added (see FIGS. 1, 2, 5, etc.). The power unit A1, the compressor unit A2, and a housing (a general housing 9 or a first housing 91) described below constitute an outdoor unit A. The power unit A1 is composed of a gas engine 1, a DC generator 2, a first coolant circulation flow path 51, a second coolant circulation flow path 52, a second radiator 62, and a second fan 64 (see FIGS. 1, 2, 5, etc.). Here, the outdoor unit A is often installed indoors in a building such as a multi-family housing complex, such as a building, condominium, or apartment, for example, in the basement or machine room of the building. It may also be installed outdoors in a building like a normal air conditioning or heating system.

[0017] The compressor unit A2 is configured by assembling a motor 3, a compressor 41, a first radiator 61, a condenser 42, and a first fan 63. The indoor unit is configured by a refrigerant flow path 72, an indoor unit 71, etc. Hereinafter, the motor 3 will be described as a DC motor, but in the present invention, an embodiment of the motor 3 may also be an AC motor 3A, and this AC motor 3A will be described at the end of the explanation.

[0018] In the following description, motor 3 is a DC motor, and if motor 3 is an AC motor, it is designated by the reference symbol 3A and will be described as AC motor 3A. In the following description, where it is emphasized that motor 3 is a DC motor, it will be referred to as DC motor 3. Furthermore, in the drawings, motor 3 will be referred to as a DC motor in embodiments in which a DC motor is used, and will be referred to as an AC motor in embodiments in which an AC motor is used.

[0019] The power unit A1 and the compressor unit A2 are connected via a first coolant circulation flow path 51 so that the coolant for the gas engine 1 can circulate (see FIGS. 1, 2, 5, etc.). The compressor unit A2 is also connected to an indoor unit 71 via a refrigerant flow path 72. The refrigerant flow path 72 includes a heating refrigerant flow path 72a and a cooling refrigerant flow path 72b. The heating refrigerant flow path 72a is a flow path (pipe) through which the refrigerant flows during heating (see FIGS. 2 to 4), and the cooling refrigerant flow path 72b is a flow path (pipe) through which the refrigerant flows during cooling (see FIGS. 5 to 7).

[0020] The compressor unit A2 and the heating refrigerant flow path 72a or the cooling refrigerant flow path 72b serve to supply refrigerant in a state suitable for heating or cooling to the indoor unit 71. The power unit A1 and the compressor unit A2 are incorporated together into a single overall housing 9. The power unit A1, the compressor unit A2, and the overall housing 9 constitute the outdoor unit A.

[0021] Condenser 42 may also be referred to as a heat exchanger. That is, during heating, condenser 42 functions as a heat exchanger that obtains heat from the air and raises the temperature of the refrigerant gas at the inlet of compressor 41. During cooling, condenser 42 exposes the heat of the refrigerant gas, which has been compressed and heated by compressor 41, to passing air, thereby condensing the refrigerant gas into a liquid.

[0022] In the power unit A1, the gas engine 1 and the DC generator 2 are connected by a coupling 14, and the DC generator 2 generates electricity when the gas engine 1 is driven (see FIG. 1). The electric power generated by the DC generator 2 is transmitted to the compressor unit A2 side and supplied to the motor 3 via a controller 35. In the compressor unit A2 side, the motor 3 drives the compressor 41.

[0023] The gas engine 1 of the power unit A1 is provided with a first cooling water circulation path 51 and a second cooling water circulation path 52 (see FIGS. 1 to 7, etc.). Cooling water circulates through both the first cooling water circulation path 51 and the second cooling water circulation path 52, and a water path switching valve 53 controls whether the cooling water flows through one of the first cooling water circulation path 51 and the second cooling water circulation path 52 (see FIGS. 1 to 7).

[0024] The first coolant circulation flow path 51 is a flow path that is arranged across both the power unit A1 and the compressor unit A2, with the gas engine 1 at the center. The second coolant circulation flow path 52 is a flow path that is arranged only in the gas engine 1 of the power unit A1. In the outdoor unit A, the coolant circulates through the first coolant circulation flow path 51 during heating, and the coolant circulates through the second coolant circulation flow path 52 during cooling.

[0025] The first coolant circulation flow path 51 is provided between the power unit A1 and the compressor unit A2, and cools the gas engine 1 while also managing the temperature of the condenser 42. The second coolant circulation flow path 52 cools the gas engine 1 inside the power unit A1 while it is running. The coolant flows through either the first coolant circulation flow path 51 or the second coolant circulation flow path 52 by the water path switching valve 53, but does not flow through both paths simultaneously.

[0026] The first coolant circulation flow path 51 and the second coolant circulation flow path 52 share a flow path on the inlet side and part of the outlet side from the gas engine 1 (see Figures 1(A), 2, 3, etc.). A water path switching valve 53 is provided in the flow path on the outlet side. The water path switching valve 53 is operated by a TCU (total control unit) 66 to switch to either the first coolant circulation flow path 51 or the second coolant circulation flow path 52 depending on whether heating or cooling is being performed.

[0027] The second coolant circulation flow path 52 is provided in the gas engine 1 of the power unit A1, and a second radiator 62 is provided in the second coolant circulation flow path 52. The second radiator 62 is provided with a second fan 64, and the second fan 64 provides a passing airflow to the second radiator 62. The second coolant circulation flow path 52 only cools the gas engine 1.

[0028] The first coolant circulation flow path 51 is disposed between the power unit A1 side and the compressor unit A2 side, and is provided with a first radiator 61, and a first fan 63 is provided adjacent to the first radiator 61. The condenser 42 is disposed between the first radiator 61 and the first fan 63. The first fan 63 provides airflow through the first radiator 61, and this airflow affects the temperature of the condenser 42; in other words, the temperature of the condenser 42 is regulated by the first coolant circulation flow path 51, the first radiator 61, and the first fan 63.

[0029] On the compressor unit A2 side, the compressor 41 and the condenser 42 are incorporated into a refrigerant flow path 72, and a refrigerant flows through the compressor 41 and the condenser 42. An indoor unit 71 is incorporated into the refrigerant flow path 72. As a result, a heating and cooling system is formed by the compressor unit A2 as the outdoor unit A and the indoor unit 71 (see FIGS. 1 to 7).

[0030] Next, cooling and heating operations will be described with reference to Figs. 2 to 7. First, the configuration of the cooling and heating system, the flow of refrigerant and engine coolant, and the operation of the cooling and heating system will be described. The thick solid lines in Figs. 1 to 7 indicate the refrigerant flow path (refrigerant piping) 72. The arrows on the refrigerant flow path 72 indicate the direction of refrigerant flow during heating and cooling. The dashed line (chain line) between the refrigerant flow path 72 and the TCU (Target Control Unit) 66 indicates the signal line of the TCU (Target Control Unit) 66.

[0031] In the present invention, the selection of either heating or cooling is made directly by a command from the TCU (total control unit) 66, and that command operates the water passage switching valve 53 on the power unit A1 side to switch between the first coolant circulation path 51 and the second coolant circulation path 52, and the refrigerant path 72 on the compressor unit A2 side is switched between a heating refrigerant path 72a and a cooling refrigerant path 72b by the switching operations of a main refrigerant path switching valve 73m and a sub refrigerant path switching valve 73n. The main refrigerant path switching valve 73m switches the refrigerant path 72 between the compressor 41 and the condenser 42, and the sub refrigerant path switching valve 73n switches the refrigerant path 72 on the indoor unit 71 side between the heating refrigerant path 72a and the cooling refrigerant path 72b.

[0032] 16, the main refrigerant passage switching valve 73m and the sub refrigerant passage switching valve 73n have substantially the same structure and include a rotary valve portion 73r therein, which, when rotated left or right, connects the passage switching port 73c to the passage switching port 73a, or the passage switching port 73c to the passage switching port 73b. This rotation is performed by an actuator 73u in response to a signal from a TCU (total control unit) 66.

[0033] The switching positions set by the TCU (total control unit) 66 determine whether the heating and cooling system operates as a heater or a cooler. The TCU (total control unit) 66 sends a command to the ECU (engine control unit) 67, which then starts the gas engine 1 with the starter 11 using power from the battery 12. The ECU (engine control unit) 67 also controls operating variables such as the ignition timing, air-fuel ratio, and throttle rotation of the gas engine 1. To this end, it adjusts the throttle rotation so that the engine speed of the gas engine 1 remains constant, and controls the fuel pressure regulator so that the air-fuel ratio becomes the stoichiometric air-fuel ratio.

[0034] The heating operation of the gas engine heating and cooling system of the present invention will be explained with reference to Figures 2 to 4. First, although it depends on the region, in a typical building, the temperature difference between the indoor and outdoor air is larger in winter than in summer. Therefore, improvement of heating performance is desired. The present invention is characterized by regenerating a portion of the thermal energy radiated into the cooling water of the gas engine 1 and the housing.

[0035] First, in response to a command from the TCU (total control unit) 66, the water passage switching valve 53 switches the coolant passage to flow into the first coolant circulation passage 51 (see FIG. 2). The refrigerant passage 72 between the main compressor 41 and the condenser 42 is switched to a passage corresponding to heating by the main refrigerant passage switching valve 73m, and the heating refrigerant passage 72a is selected by the sub refrigerant passage switching valve 73n, and the refrigerant flows through the heating refrigerant passage 72a and circulates through the refrigerant passage 72 (see FIGS. 2 to 4). Then, the coolant for the gas engine 1 flows through the first coolant circulation passage 51, passes through the radiator core 61a of the first radiator 61, releases heat into the atmosphere, is sucked in by the coolant pump 13, and returns to the water jacket of the gas engine 1.

[0036] The power of the gas engine 1 drives the DC generator 2 via a coupling 14. The power generated by the DC generator 2 is supplied to the motor 3 through a controller 35 that controls the output of the motor 3 (see FIG. 17(A)). In addition, surplus power generated by the DC generator 2 due to the output of the gas engine 1 can be supplied to the outside as AC power. Specifically, an inverter 65 is connected to the DC generator 2, and at the same time as supplying power to the motor 3, the inverter 65 converts the power into a predetermined power (e.g., 100 V, 50 Hz) and supplies it to the outside as AC power (see FIGS. 1 to 8, etc.).

[0037] A specific example of the controller 35 is a type that controls the current at the inlet or outlet of the motor 3. In this example, a large current transistor 35t is used on the inlet or outlet side of the motor 3. FIG. 17(B) shows inlet side control, where the controller 35 is provided on the inlet side of the motor 3. FIG. 17(C) shows outlet side control, where the controller 35 is provided on the outlet side of the motor 3.

[0038] When the output of the motor 3 is increased by inlet side control, a command is sent from the TCU (total control unit) 66 to the controller 35 to increase the current flowing from point b (base) to point e (emitter) of the controller 35. This significantly increases the current flowing through point c (collector), point b (base), and point e (emitter) of the transistor 35t, increasing the output of the motor 3 and increasing the heating or cooling capacity. Outlet side control has approximately the same effect as inlet side control, so please refer to inlet side control.

[0039] The engine coolant flows through a core 61a of a first radiator 61 in the first coolant circulation passage 51 and dissipates heat in the first radiator 61 (see FIGS. 3 and 4). The high-temperature, high-pressure refrigerant gas from the compressor 41 exits from the top of the compressor 41 in the drawing and returns to the bottom, as shown in FIGS.

[0040] The high-temperature, high-pressure gaseous refrigerant flows through the heating-mode refrigerant flow path 72a by switching the secondary refrigerant passage switching valve 73n to the heating-mode refrigerant flow path 72a, which is in a blocked state. At this time, the refrigerant cannot pass through the cooling-mode refrigerant flow path 72b of the refrigerant flow path 72. In the heating-mode refrigerant flow path 72a, as shown in Figures 2 to 4, the refrigerant flows as shown by the arrows in the refrigerant flow path 72, passes through the secondary refrigerant passage switching valve 73n, and passes through the core 71a of each indoor unit 71, releasing heat into the room (see Figures 2 and 3).

[0041] At this time, the refrigerant has high gas temperature and pressure until it reaches each expansion valve 71b. After passing through the expansion valve 71b, the temperature and pressure decrease, and naturally the temperature becomes lower than the outside air temperature. Then, as shown by the arrow, the refrigerant passes through the refrigerant flow path 72 and enters the suction port (lower side) of the condenser 42. Here, it receives heat and is sucked from the lower side of the compressor 41 via the main refrigerant passage switching valve 73m. Note that the refrigerant is similarly sucked from the lower side of the compressor 41 during cooling.

[0042] Here, the first fan 63 rotates in a direction to draw outside air into the general housing 9 in response to a command from the TCU (total control unit) 66 (see FIGS. 2 to 4). Air entering from outside the general housing 9 passes through the radiator core 61a of the first radiator 61 as passing air, and the heated passing air passes through the condenser 42, heating the condenser 42. This allows the refrigerant in the condenser 42 to receive more heat than if it were superheated by outside air alone (see FIGS. 2 and 3). The refrigerant heated in the condenser 42 passes through the main refrigerant passage switching valve 73m and flows back to the suction (inlet) side of the compressor 41. When compressed by the compressor 41, the refrigerant reaches a higher temperature, providing a heating effect. As will be described later, if the temperature of the refrigerant gas returning to the suction side of the compressor 41 increases, the heating performance will be further improved.

[0043] Furthermore, by rotating the second fan 64 on the power unit A1 side in a direction that causes the airflow to flow from the inside to the outside of the overall housing 9 and be discharged, the amount of air passing through the condenser 42 together with the first fan 63 is further increased, further enhancing the heating effect (see FIG. 10(B)). Note that during heating, as described above, the water passage switching valve 53 switches so that all of the engine coolant flows through the radiator core 61a of the first radiator 61, and the radiator core 62a of the second radiator 62 is not functioning. The airflow passing through the first fan 63 and the second fan 64 does not interfere with the cooling of the gas engine 1.

[0044] Here, we will explain how raising the refrigerant gas temperature on the inlet side of compressor 41 contributes to an increase in the temperature on the outlet side. According to the laws of thermodynamics, when compressor 41 compresses gas with a volume Vin on the inlet side to Vout (Vin / Vout), if the gas temperature before compression (inlet) is TinK (Kelvin) and the temperature after compression (outlet) is ToutK, then the following holds: TIFF0007604055000001.tif10163

[0045] This value "n" is sometimes referred to as "κ (kappa)" in the case of adiabatic compression, and is a value specific to each gas. For example, the value of helium, a monoatomic molecule, is 1.66, while the value of air, a mixture of diatomic molecules, is 1.4. The greater the number of atoms that make up the molecule, the smaller the value becomes. In the case of isothermal compression, n = 1 regardless of the type of gas. In the following explanation, n for refrigerant gases is assumed to be 1.07.

[0046] Assume that the air is compressed to 1 / 20 of its original volume by the compressor 41. Let Tin be 5°C (278K), which is close to the limit at which the heat pump can operate, and compare it with the outlet temperature Tout when heated to 30°C (303K) as in the present invention.

[0047] TIFF0007604055000002.tif19163

[0048] TIFF0007604055000003.tif21163As you can see, the temperature of the heat source that can be used for heating differs by 32°C. The higher Vin / Vout, the greater this difference becomes.

[0049] Next, the cooling operation will be described with reference to Figures 5 to 7. During cooling, the second cooling water circulation flow path 52 is selected by the water path switching valve 53, and cooling water does not flow through the first cooling water circulation flow path 51. In other words, when the second cooling water circulation flow path 52 is selected by the water path switching valve 53 during cooling, cooling water flows inside and around the gas engine 1 and only serves to cool the gas engine 1.

[0050] Furthermore, the refrigerant flow path 72 between the main compressor 41 and the condenser 42 is switched by the main refrigerant passage switching valve 73m to a passage corresponding to cooling, and the sub-refrigerant passage switching valve 73n selects the cooling refrigerant flow path 72b, and the refrigerant flows through the cooling refrigerant flow path 72b and circulates through the refrigerant flow path 72 (see Figures 5 to 7). The compressor 41 driven by the motor 3 compresses the gaseous refrigerant (which may contain a small amount of liquid) and the refrigerant becomes a high-temperature gas, which then passes through the main refrigerant passage switching valve 73m, which is in the switching position shown in Figures 5 to 7, and enters the condenser 42. Here, the refrigerant releases heat, lowering its temperature and becoming liquid (including gaseous), and when it passes through the expansion valve 71b of the indoor unit 71, it quickly vaporizes and expands, significantly lowering its temperature, and the core 71a absorbs heat from the indoor air, lowering the air temperature.

[0051] The gaseous refrigerant expanded in the indoor unit 71 returns to the suction side of the compressor 41 through the cooling-mode refrigerant flow path 72b selected by the sub-refrigerant path switching valve 73n (see FIGS. 5 to 7). Thus, during cooling, the first coolant circulation flow path 51 is blocked by the water path switching valve 53, and the coolant does not flow through the first coolant circulation flow path 51. Therefore, the coolant does not pass through the first radiator 61, and does not warm the condenser 42 or the refrigerant therein. In addition, when the second fan 64, which can rotate forward and backward, is rotated to draw in outside air, it cools the first radiator 61 and increases the amount of air passing through the radiator core 61a, which is advantageous for cooling the engine during cooling.

[0052] 1(A), 2, and 5, the power unit A1 and the compressor unit A2 are housed in a single overall housing 9 to form the outdoor unit A. In contrast to this, there is an embodiment in which the overall housing 9 is divided into two housings, a first housing 91 and a second housing 92 (see FIG. 12). The first housing 91 houses a power supply system including the gas engine 1, DC generator 2, TCU (overall controller) 66, ECU (engine control unit) 67, second coolant circulation flow path 52, second radiator 62, and second fan 64 that constitute the power unit A1. The second housing 92 houses the motor 3, controller 35, compressor 41, condenser 42, first radiator 61, and first fan 63 that constitute the compressor unit A2. The only things connecting the first housing 91 and the second housing 92 are the first coolant circulation flow path 51, a signal line, and a cable that transmits the electricity generated by the DC generator 2, and the air conditioning refrigerant flow path (refrigerant piping) 72 is provided only in the second housing 92.

[0053] By separating the power unit A1 and the compressor unit A2 and storing them in the first housing 91 and the second housing 92 in this way, if the gas engine 1 on the power unit A1 side has excess power and ample electric power, it is possible to operate one power unit A1 stored in the first housing 91 and multiple compressor units A2 stored in the second housing 92 in parallel (see FIG. 13). This type of configuration has the following advantages.

[0054] In other words, this system can be installed extremely efficiently as a heating and cooling system for buildings with many rooms or multiple floors. The first housing 91 containing the power unit A1 is used as the main unit, and this single power unit A1 is installed indoors, such as in the basement or in the main power room or machine room of the building (see FIG. 13). Multiple second housings 92 containing compressor units A2 are provided and arranged in parallel on each floor. The compressor units A2 integrated into these second housings 92 are installed on each floor, and each compressor unit A2 serves multiple indoor units installed on each floor. This allows for extremely effective use of the electricity generated by the power unit A1 integrated into the first housing 91, resulting in a low-cost heating and cooling system. The first housing 91 may also be installed outdoors.

[0055] Power is supplied to the outside by an inverter 65 of the power unit A1 in the first housing 91 (see FIG. 1). Specifically, a DC / AC (direct current / alternating current) inverter is used as the inverter 65. The inverter is also sometimes called a converter. The first housing 91 housing the power unit A1 is installed in a basement or on the roof, and a second housing 92 housing the compressor unit A2 is provided on each floor or building. This shortens the refrigerant flow path (refrigerant piping) 72 from each second housing 92 to each indoor unit 71, and reduces the exchange of heat between the refrigerant and the atmosphere in the refrigerant flow path (refrigerant piping) 72, thereby improving air conditioning performance.

[0056] Next, we will explain a specific example of the relationship between the thermal efficiency of a gas engine heating and cooling device and the overall thermal efficiency of a heat pump system in this invention. The calculations are based on the assumption that the output of the gas engine 1 is 20 kW, the surplus power (power supplied to the outside) is 5 kW, and the power generation efficiency and inverter efficiency are each 95%. For simplicity's sake, we will assume that the slightly less than 1 kW of power consumed by the electric fan and controls inside the housing is included in this 5 kW.

[0057] If the engine output is 20 kW, 5.54kw (5kw×1 / 0.95×1 / 0.95...external power supply) 14.46kw (20kw - 5.54kw)...heat pump power.

[0058] Of this power, the power that can be consumed by the DC motor 3 is 14.46kW x 0.95 = 13.74kW, assuming the efficiency of the motor controller 35 is 95%. Because waste heat is recovered, a COP (coefficient of performance) of 5.5 or more can be ensured even when using heating. The heat energy that can be used for heating obtained from the above 13.74 kW of electricity is: 13.74 x 5.5 = 75.57 kW.

[0059] Therefore, (heating thermal energy) + (external power supply) - 80.57kW On the other hand, if the thermal efficiency of the engine is ηE, the energy Qf of the fuel is: Qf=20kw / ηE. Therefore, the overall thermal efficiency ηT is ηT=80.57kw / (20kW / ηE)≒4ηE···(1) This becomes:

[0060] By pursuing the rapid combustion and cooling loss to the utmost limit and making full use of the inertial intake and exhaust phenomenon, a thermal efficiency of 44% or more can be achieved even when operating at the theoretical air-to-fuel ratio to activate a three-way catalyst of 16kJ in a gas engine. Furthermore, by keeping the normal engine speed below 2400 rpm, friction loss can be reduced to 7% or less, and the engine's mechanical efficiency will be 93% or more. In this way, the thermal efficiency of the engine is ηE=44×0.93≧40.92% (2) This becomes:

[0061] From equations (1) and (2), ηT≧4×0.4=1.6 In other words, the overall thermal efficiency is 160%. If all of the power generated by the DC generator 2 were used to drive the compressor 41, this system could achieve an overall thermal efficiency of 200% or more.

[0062] As mentioned above, even when operating at the theoretical air-fuel ratio to activate the three-way catalyst 16k, in order to achieve a higher indicated thermal efficiency than lean burn or pre-chamber types, the surface area of ​​the combustion chamber is reduced as shown in Figure 15, and simultaneous ignition from two locations shortens the flame propagation distance. Furthermore, the reflection of the flame raises the gas temperature in the unburned parts, increasing the flame propagation speed.

[0063] In gas engine 1, the combustion chamber is point-symmetrical with respect to the center of the cylinder, the intake valve 16a and the exhaust valve 16b have the same (or nearly the same) valve head diameter, and the two spark plugs 16c are also arranged symmetrically. Their centers are on a circle that is half the cylinder diameter. Furthermore, extensions of these centerlines intersect at point 0 on the centerline of the cylinder. The combustion chamber is a thin spherical shell with a radius R centered at this point 0, and the ignition point and the valve heads of the intake valve 16a and exhaust valve 16b are approximately aligned with the spherical shell.

[0064] The air-fuel ratio is controlled by a signal from an O2 sensor 16d installed in the exhaust system, and the pressure of the gas fuel supplied to the mixer 16f is adjusted by a fuel pressure regulator 16g so that the theoretical air-fuel ratio is achieved. The engine speed sensor 16h installed near the flywheel 15 detects the rotation speed of the crankshaft 16s, and when the load on the gas engine 1 increases and the rotation speed drops, the throttle opening is adjusted to maintain a predetermined rotation speed (e.g., 2200 rpm) (see Figure 15). If the rotation speed is high, the throttle is moved in the closing direction.

[0065] To reduce friction loss, the stroke is not long, but is kept at or slightly longer than the cylinder diameter, as shown in Figure 15. A high compression ratio (12 or more) is achieved not simply by increasing the stroke, but by using the compact combustion chamber mentioned above. The engine speed, air-fuel ratio, ignition timing, and engine start / stop are all controlled by the ECU (engine control unit) 67. Torque fluctuations caused by the intake, compression, expansion, and exhaust strokes cause fluctuations in engine speed. Even slight fluctuations in this speed (say, 1 / 50) can impair power generation efficiency. Therefore, a coupling 14 is inserted between the flywheel 15 and the DC generator 2 to smooth out vibrations in the rotational direction.

[0066] Next, an example of the structure of the coupling 14 that connects the gas engine 1 and the DC generator 2 is shown. As shown in Figure 14, the coupling 14 consists of a buffer member 14a, two flanges 14b, and a pin 14p. The flange 14b is a roughly Y-shaped member (see Figure 14(C)), and at its center, a spline hub 14h is formed as a female spline at 120-degree intervals along the circumferential direction. Three arm-like pieces 14c are arranged radially with the spline hub 14h as the diametric center, and connecting holes 14d through which the pin 14p passes are formed at the tips of the arm-like pieces 14c.

[0067] The buffer member 14a has a generally cylindrical shape and is made of an elastic material, such as rubber or synthetic resin (see FIG. 14(D)). A through-hole 14f is formed in the axial direction at the center of the diameter of the buffer member 14a, and the splined hub 14h of the flange 14b is loosely inserted into the through-hole 14f. "Loosely inserted" here means that the splined hub 14h is inserted into the through-hole 14f with some clearance, allowing the splined hub 14h to move within the through-hole 14f with some play. Six tubular sleeves 14e are arranged at equal intervals (60 degrees) along the axial direction near the outer periphery of the buffer member 14a. The pins 14p are press-fit into the sleeves 14e.

[0068] The flanges 14b are disposed at both axial ends of the buffer member 14a so as to face each other. The arm pieces 14c of the flanges 14b are not in phase with each other and are disposed 60 degrees apart from each other. Three pins 14p are disposed at 120-degree intervals near the outer periphery of the spline hub 14h of each flange 14b. The pins 14p are inserted into connecting holes 14d at the tips of the arm pieces 14c and into sleeves 14e provided in the buffer member 14a, connecting the buffer member 14a and the flanges 14b. In this way, the coupling 14 is used as a flange joint that can be elastically deflected along the axial direction.

[0069] Meanwhile, an adapter 15a with a male spline 15s at its center is fixed with bolts to the flywheel 15 attached to the gas engine 1. The DC generator 2 is also equipped with a male spline 2s. The spline 15s of the flywheel 15 and the spline 2s of the DC generator 2 are inserted into spline hubs 14h on both axial sides of the coupling 14, enabling rotational drive transmission between the gas engine 1 and the DC generator 2. Torque from the gas engine 1 is smoothed and transmitted from the spline 2s on the DC generator 2 side to the DC generator 2 via the buffer member 14a of the coupling 14. In this invention, gaseous refrigerant (including a small portion in liquid form) that has just been pressurized by the compressor 41 is directly circulated without using an intermediate refrigerant such as water.

[0070] In the present invention, there is an embodiment in which the second fan 64 that sends airflow to the second radiator 62 is configured to be able to change the direction of the airflow to the second radiator 62 (see FIG. 9). In this embodiment, the propeller of the second fan 64 is rotated forward and backward, so that the direction of the airflow to the second radiator 62 can be changed between forward and reverse rotation. This makes it possible to prevent the power unit A from overheating and damaging the device during cooling in the summer.

[0071] The following situations are particularly likely to occur in the summer. First, engine output decreases due to a decrease in intake air density. Second, in the case of a spark-ignition engine, knocking may occur, potentially damaging the engine. Third, overheating of the generator reduces power generation efficiency and inverter conversion efficiency. These inconveniences can be resolved by controlling the air flow within the overall housing 9 by rotating the second fan 64, which can rotate in both forward and reverse directions, as described above, depending on the situation, thereby maintaining a good environment within the overall housing 9 (see FIG. 8).

[0072] First, the temperature of the housing (the overall housing 9, the first housing 91, or the second housing 92) is detected, and when it reaches 60°C, a TCU (overall control unit) 66 commands the second fan 64 to change from forward rotation to maximum reverse rotation, introducing outside air into the housing to cool it down. The second fan 64 has a plurality of blades 64, each of which has a flat blade center portion 64a in the middle along the rotation direction, and has blade end portions 64b, 64c at both ends of the blade center portion 64a in the rotation direction, and the angle of attack α+β of both blade end portions 64b, 64c is the same and is set to an angle α smaller than the angle of attack of the blade center portion 64a.

[0073] This section describes the second fan 64, which can rotate forward and backward and is used in the gas engine air conditioner of the present invention. This second fan 64 is driven by an electric motor to easily rotate forward and backward without using gears or the like. Conventional fan blades are cambered (for example, arc-shaped) to increase efficiency. When the fan is rotated clockwise (forward) as viewed from the front, efficiency is improved compared to a flat fan-like fan. However, a problem occurs when the fan rotates in the reverse direction, as the air volume decreases.

[0074] In contrast, the second fan 64 shown in Figure 9, when combined with flat plates, has the same angle of attack in both forward and reverse rotation, ensuring the same airflow regardless of forward or reverse rotation, making it ideal for the present invention. Next, we will explain its operation. In the second fan 64, the blades are designated as a blade center 64a and blade ends 64b and 64c. The central blade center 64a has the same angle of attack (α + β) in both forward and reverse rotation. In forward rotation, the blade end 64c becomes the leading edge, and the angle of attack of this portion is α, which is smaller by β than that of the blade center 64a, thereby reducing the impact with the air. Also in Figure 9, reference numeral 64d denotes a blade mounting portion, and 64e denotes a motor that rotates the second fan 64.

[0075] Another embodiment of the second fan 64 shown in FIG. 10 has a four-blade structure similar to that shown in FIG. 9, with the same angle of attack in both forward and reverse rotation, providing the same airflow regardless of forward or reverse rotation. The blade center 64a, blade ends 64b and 64c, and motor 64e are similar to those shown in FIG. 9, with the blade mounting portion 64d being cylindrical. In particular, the angle of attack α+β is approximately 30 degrees, and the angle α is approximately 25 degrees. This shape is considered optimal. Furthermore, as shown in FIG. 11(D), a three-blade structure also provides the same effects as a four-blade structure.

[0076] Furthermore, the blade tip 64b becomes the trailing edge, but its angle is smaller than that of the blade center 64a, reducing vortices generated on the back surface. This three-stage bend makes the blade more similar to a cambered blade than a fan-shaped blade. In the case of reverse rotation, the blade tip 64b becomes the leading edge and the blade tip 64c becomes the trailing edge, resulting in the same shape as in forward rotation. Therefore, while forward rotation does not achieve the same performance as a cambered blade, the same air volume can be ensured in both forward and reverse rotation. The direction in which the second fan 64 rotates so that the passing air enters from the outside of the overall housing 9 into the inside of the overall housing 9 is defined as the forward rotation direction. The direction in which the second fan 64 rotates so that the passing air is expelled from the inside of the overall housing 9 to the outside of the overall housing 9 is defined as the reverse rotation direction.

[0077] The rotation directions of the first fan 63 and the second fan 64 will be described during cooling, overheating, and heating. During cooling, overheating, and heating, the first fan 63 always rotates forward and operates to draw passing air from the outside of the general housing 9 to the inside of the general housing 9. The second fan 64 has a structure that allows forward and reverse rotation. During cooling, as shown in FIG. 10(A), passing air flows unidirectionally within the general housing 9 from the first radiator 61 side to the second radiator 62 side. The second fan 64 rotates in the reverse direction and acts to draw passing air from the inside of the general housing 9 to the outside of the general housing 9. Because it is during cooling, no cooling water is circulating through the first cooling water circulation channel 51 and the first radiator 61.

[0078] During overheating, as shown in FIG. 8(B), strong ventilation is required inside the overall housing 9. Therefore, ventilation is performed by introducing passing air into the overall housing 9 using the first fan 63 and the second fan 64. Both the first fan 63 and the second fan 64 rotate strongly in the forward direction. At this time, no coolant is circulating through the first coolant circulation flow path 51 and the first radiator 61.

[0079] During heating, as shown in Fig. 8(C), a strong passing wind is caused to flow from the first radiator 61 side to the second radiator 62 side inside the overall housing 9. The second fan 64 is rotated in the reverse direction or is stopped. During heating, the coolant is circulating through the first coolant circulation flow path 51 and the first radiator 61.

[0080] In the above description, the motor 3 has been described as a DC motor. An embodiment in which an AC motor 3A is used as the motor 3 will be described with reference to FIGS. 18 to 20. In this embodiment, an AC generator 2A is used instead of the DC generator 2, and the motor 3 is an AC motor 3A, as described above (see FIGS. 16 to 18). The configuration and arrangement of the gas engine 1, first coolant circulation flow path 51, second coolant circulation flow path 52, compressor 41, condenser 42, and other components, as well as the functions of the coolant and refrigerant during heating and cooling, are the same as those of the embodiment using the DC generator 2 and DC motor 3 described above, and therefore refer to FIGS. 2 to 7. In this embodiment, the AC generator 2A sends AC current to the AC controller 35A via the gas engine 1.

[0081] The AC controller 35A is different from the one corresponding to the DC motor 3, and the one corresponding to the AC motor 3A will be described. The controller 35A includes a rectifier 35a. The rectifier 35a has the role of adjusting the fundamental frequency to be suitable for the AC motor 3A when sending current from the AC generator 2A to the AC motor 3A (see FIG. 20).

[0082] Furthermore, this fundamental frequency needs to be amplified to drive the AC motor 3A. Therefore, the AC current of the fundamental frequency is sent to a large-capacity transistor 35t, and an AC signal that amplifies the frequency to the drive frequency required to operate the AC motor 3A is sent to this transistor 35t in response to a command from a TCU (total control unit) 66 (see Figure 20(B)).

[0083] This transistor 35t amplifies the fundamental frequency generated by the rectifier to a drive frequency required to rotate and drive the AC motor 3 A. By issuing a command from the TCU (total control unit) 66, the rotational speed of the AC motor 3 A is increased by a drive frequency that is amplified by a larger amount than the fundamental frequency, thereby increasing the cooling / heating capacity.

[0084] Furthermore, by reducing the amplification amount of the fundamental frequency to set the drive frequency according to a command from the TCU (total control unit) 66, it is possible to reduce the heating / cooling capacity and save energy. Specifically, when increasing the output of the AC motor 3A, the TCU (total control unit) 66 issues a command to the controller 35 to increase the current flowing from point b (base) to point e (emitter) of the controller 35. This significantly increases the current flowing through point c (collector), point b (base), and point e (emitter) of the transistor 35t, increasing the output of the AC motor 3A and increasing the heating or cooling capacity.

[0085] In an embodiment of a heating and cooling device using an AC generator 2A and an AC motor 3A, an AC-AC inverter (see FIG. 20(A)) is used as the inverter 65. The inverter 65 (AC-AC inverter) stabilizes the high-voltage AC current generated by the AC generator 2A and adjusts it so that it can be used as a general AC power source.

[0086] 19 shows an embodiment in which an AC generator 2A is used as the generator and a DC motor is used as the motor 3. In this embodiment, AC power generated by the AC generator 2A is converted to DC by a controller 35 and electricity is sent to the DC motor 3. [Explanation of symbols]

[0087] A1...power unit, A2...compressor unit, 1...gas engine, 2...DC generator, 2A...AC generator, 3...motor, 3A...AC motor, 41...compressor, 42...condenser, 51...first cooling water circulation channel, 52... second cooling water circulation flow path, 53... water path switching valve, 61... first radiator, 62...second radiator, 63...first fan, 64...second fan, 66...TCU (total control unit), 67...ECU (engine control unit), 9... overall housing, 91... first housing, 92... second housing, 64a... center of blade, 64b, 64c…the tip of the quill, α+β…the angle of attack.

Claims

1. a gas engine air conditioner including an overall housing having a gas engine, a first cooling water circulation flow path and a second cooling water circulation flow path through which cooling water for the gas engine circulates, a first radiator provided in the first cooling water circulation flow path, a second radiator provided in the second cooling water circulation flow path, a water path switching valve for circulating the cooling water to either the first cooling water circulation flow path or the second cooling water circulation flow path, a direct current generator driven by the gas engine, a motor operated by the direct current generator, a compressor driven by the motor for compressing a refrigerant, a condenser for heat exchange with the refrigerant, a first fan which rotates only in the forward direction and provides a passing airflow to the first radiator, and a second fan which rotates in the forward and reverse directions and also provides a passing airflow to the second radiator, During cooling and heating, the first fan rotates in a forward direction and the second fan rotates in a reverse direction, so that passing air flows in one direction from the first radiator side to the second radiator side, a gas engine heating and cooling device configured such that, in the event of overheating, cooling water is caused to flow into the second cooling water circulation flow path via the water path switching valve, and the first fan rotating in the forward direction and the second fan rotating in the forward direction introduce passing air into the overall housing to ventilate, the second fan has a plurality of blades, each of which has a flat blade center portion midway along the direction of rotation and has blade end portions at both ends of the blade center portion in the rotation direction, the angle of attack of the blade center portion of the second fan being α+β in the forward and reverse rotations, and both blade end portions of the blade are bent at the same angle α, and the second fan can ensure the same air volume in both the forward and reverse rotations.

2. 2. The gas engine air conditioner according to claim 1, wherein the number of blades of the second fan is four.

3. 2. The gas engine air conditioner according to claim 1, wherein the number of blades of the second fan is three.

4. 3. The gas engine air conditioner according to claim 1, wherein the angle of attack of the blades of the second fan (α+β) is 30 degrees, and the angle of attack (α) is 25 degrees.

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