Liquid pumps and combustion systems

Abstract

The present invention provides a liquid pump and a combustion system using the liquid pump that can suppress vaporization of the liquid inside the pump chamber and prevent the product from becoming larger, in a liquid pump that pressurizes a volatile liquid. [Solution] A liquid pump 1 for pressurizing a liquid, wherein the liquid L to be pressurized is volatile, and the pump unit 10 has a pump chamber 31 filled with the liquid L and pressurizes and discharges the liquid L in the pump chamber 31, and a motor unit 50 has an electric motor 52 that drives the pump unit 10 and is fastened to the pump unit 10, and a cooling passage 43 is provided in a heat conduction path N from the electric motor 52 to the pump chamber 31 and through which a refrigerant K flows, without being provided on the outer circumference of the electric motor 52.

Description

Technical Field

[0001] The technology disclosed in this specification relates to a liquid pump for boosting and transferring a liquid and a combustion system using the liquid pump.

Background Art

[0002] For example, in some power generation systems, liquefied gas fuels with high vapor pressures (volatility), such as ammonia, are used. In a power generation system using ammonia as fuel, liquid ammonia and gaseous ammonia are burned as fuel. Liquid ammonia is supplied to a turbine combustion chamber by a liquid pump, and gaseous ammonia obtained by evaporating the liquid ammonia is supplied to the turbine combustion chamber by a gas compressor.

[0003] Generally, a liquid pump uses an electric motor as a power source. Due to the heat generated by the operating electric motor, the liquid ammonia to be pressurized in the pump chamber is likely to vaporize. When the liquid ammonia in the pump chamber vaporizes, the viscosity of gaseous ammonia is smaller than that of liquid ammonia. Therefore, the lubricating oil film at the pump bearing sliding part and the impeller sliding part becomes thinner, and it may become a so-called dry operation, resulting in progressive wear. For this reason, various electric pumps (liquid pumps) having a structure for cooling the electric motor have been proposed.

[0004] For example, Patent Document 1 discloses a jacketed electric pump in which a cylindrical pump part is axially connected to a cylindrical motor part so that the rotation axis of the pump part and the rotation axis of the motor part are coaxial. In order to cool the motor part, the jacketed electric pump covers the outer peripheral part of the motor part (and the pump part) with a cylindrical jacket having a diameter larger than the diameter of the motor part, and circulates a cooling fluid through the space between the jacket and the motor part (and the pump part).

[0005] Furthermore, Patent Document 2 discloses a fluid pump in which one side of the rotating shaft is a motor section equipped with an electric motor, and the other side of the rotating shaft is a pump section equipped with an impeller. This fluid pump has a cylindrical motor casing that covers the outer circumference of the motor stator of the electric motor. Between the motor casing and the motor stator, a cylindrical cooling jacket is provided, which has a spiral groove formed around the rotation axis through which a coolant flows, in order to suppress heat generation from the electric motor. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Utility Model Publication No. 6-73398 [Patent Document 2] Japanese Patent Publication No. 2022-52327 [Overview of the project] [Problems that the invention aims to solve]

[0007] The jacketed electric pump described in Patent Document 1 is undesirable because the jacket, which has a larger diameter than the electric motor, covers the outer circumference of the electric motor, resulting in a larger product size.

[0008] Furthermore, the fluid pump described in Patent Document 2 is undesirable because it covers the outer circumference of the electric motor with a cooling jacket having a larger diameter than the electric motor itself, and then covers the outer circumference of the cooling jacket with a motor casing that has an even larger diameter than the cooling jacket, resulting in a large product size.

[0009] The objective of the technology disclosed herein to solve the above-mentioned problems is to provide a liquid pump and a combustion system using the liquid pump that can suppress vaporization of the liquid in the pump chamber and suppress an increase in product size in a liquid pump for pressurizing a volatile liquid. [Means for solving the problem]

[0010] To solve the above problems, the liquid pump disclosed herein takes the following measures.

[0011] The first means is a liquid pump for pressurizing a liquid, wherein the liquid is volatile, and the pump has a pump chamber filled with the liquid and pressurizes and discharges the liquid in the pump chamber; a motor has an electric motor for driving the pump and is fastened to the pump; and a cooling passage is provided in a heat conduction path from the electric motor to the pump chamber, through which a refrigerant flows, and is not provided on the outer circumference of the electric motor.

[0012] According to the first method described above, the cooling passage is not provided on the outer circumference of the electric motor, but rather in the heat conduction path from the electric motor to the pump chamber. This makes it possible to suppress vaporization of the liquid in the pump chamber and to suppress an increase in the size of the product in a liquid pump that pressurizes a volatile liquid. Furthermore, by suppressing vaporization, it is possible to suppress deterioration of the lubricity of the pump's sliding parts.

[0013] The second means is a liquid pump relating to the first means described above, wherein the pump section comprises a first pump chamber forming member having a part of the pump chamber formed thereon and a first mounting surface, and a second pump chamber forming member having a part of the pump chamber formed at a location different from the part of the pump chamber formed on the first pump chamber forming member and a second mounting surface in contact with the first mounting surface, and the cooling passage is a groove formed in at least one of the first mounting surface and the second mounting surface.

[0014] According to the second method described above, a cooling passage can be formed relatively easily.

[0015] The third means is a liquid pump relating to the first or second means described above, wherein a boosting pipe is connected to a liquid inlet communicating with the pump chamber through which the liquid is guided, and a cooling pipe is connected to a refrigerant inlet communicating with the cooling passage through which the liquid is guided.

[0016] According to the third method described above, the liquid to be pressurized is supplied from the pressurization piping to the pump room, and the liquid used as a refrigerant is supplied from the cooling piping to the cooling passage, thereby supplying the same liquid through separate paths. For this reason, there is no need to prepare a separate refrigerant in addition to the liquid to be pressurized, and there is no need for a device to circulate the refrigerant, making it convenient. Furthermore, since the liquid to be pressurized is volatile, the liquid introduced into the cooling passage provided in the heat conduction path easily vaporizes, and a high cooling effect can be obtained by utilizing the latent heat of vaporization.

[0017] The fourth means is a combustion system having a liquid pump according to the first or second means, comprising: a fuel tank storing the liquid; a combustion device that uses the liquid fuel and the gaseous fuel obtained by evaporating the liquid as fuel; a liquid fuel supply passage connected from the fuel tank to the combustion device, the liquid pump being provided to supply the liquid fuel pressurized by the pump to the combustion device; a gaseous fuel supply passage connected from the fuel tank to the combustion device, the evaporator being provided to evaporate the liquid and supply the gaseous fuel to the combustion device; and a branch passage branching off from the liquid fuel supply passage and connected to the evaporator via the cooling passage of the liquid pump.

[0018] According to the fourth method described above, the liquid to be pressurized is supplied from the liquid fuel supply passage, and the liquid to be used as a refrigerant is supplied from the branch passage, thereby supplying the same liquid through separate passages. This is convenient because it eliminates the need to prepare a separate refrigerant in addition to the liquid to be pressurized, and there is no need for a device to circulate the refrigerant. Furthermore, since the liquid to be pressurized is volatile, the liquid guided to the cooling passage provided in the heat conduction path easily vaporizes, and a high cooling effect can be obtained by utilizing the latent heat of vaporization. In addition, the fuel mixture of gas and liquid after use as a refrigerant is converted into a gas in an evaporator and supplied to the combustion device from the gaseous fuel supply passage, so that the liquid used as a refrigerant can also be used as fuel without waste. [Effects of the Invention]

[0019] The liquid pump disclosed in this specification and the combustion system using the liquid pump can suppress the vaporization of the liquid in the pump chamber and the wear of the sliding part, and can also suppress the enlargement of the product, by taking the above-mentioned means, in a liquid pump that boosts a volatile liquid.

Brief Description of the Drawings

[0020] [Figure 1] It is a cross-sectional view of the liquid pump cut by a vertical plane passing through the central axis. [Figure 2] It is a view of a part of FIG. 1 disassembled. [Figure 3] It is a view of the pump body in FIG. 2 as seen from the III direction. [Figure 4] It is an enlarged view of the AA part in FIG. 2. [Figure 5] It is a schematic configuration diagram of a combustion system to which the liquid pump is applied.

Embodiments for Carrying Out the Invention

[0021] <Overall Configuration of Liquid Pump 1 (FIGS. 1 to 4)> Hereinafter, embodiments will be described based on the drawings. FIG. 1 shows an example of a cross-sectional view of the liquid pump 1 cut by a vertical plane passing through the central axis 34Z. When the X-axis, Y-axis, and Z-axis are shown in the figure, the X-axis, Y-axis, and Z-axis are perpendicular to each other, the Z-axis direction is the vertically upward direction, and the X-axis direction and Y-axis direction are horizontal directions.

[0022] The liquid pump 1 shown in FIG. 1 is used to boost and transfer a liquid, and is provided, for example, as a component of a fuel supply system. The liquid pump 1 can be provided in the middle of a supply line connecting a liquid supply source such as a fuel tank to the place where the liquid is used, as an in-line liquid supply pump.

[0023] Liquid fuels also include liquefied gaseous fuels (fuels that have been liquefied from a gas). Liquid fuels are, for example, corrosive fuels such as liquid ammonia or high-pressure fuels. Liquid ammonia can be used as fuel as is, or it can be used to produce hydrogen fuel by thermal decomposition. In the liquid pump 1 described in the following embodiment, we will describe an example in which volatile liquid ammonia is the liquid to be pressurized. As shown in Figure 1, the liquid pump 1 has a pump section 10 and a motor section 50, etc.

[0024] <Pump Housing 11> The pump unit 10 includes a pump housing 11, as shown in Figure 1. In one embodiment, the pump housing 11 is composed of a pump body 12, an impeller chamber cover 13, a rotor chamber cover 14, etc. The impeller chamber cover 13 and the rotor chamber cover 14 are fixed to the pump body 12 by an appropriate method such as bolt fastening.

[0025] The pump body 12 is provided with a liquid inlet 12A into which liquid L flows, connected to a liquid supply source, and the impeller chamber cover 13 is provided with a liquid outlet 13A into which liquid L flows out, connected to a liquid usage system. A pressurizing pipe (not shown) is connected to the liquid inlet 12A, and the liquid to be pressurized is guided to the liquid inlet 12A. A liquid discharge pipe (not shown) is connected to the liquid discharge port 13A, and the liquid to be pressurized is discharged from the liquid discharge port 13A.

[0026] <Impeller 20 and its surroundings> The pump section 10 can be, for example, a vortex pump (also called a Wesco pump or regenerative pump). An impeller 20 is provided between the pump body 12 and the impeller chamber cover 13 inside the pump housing 11. The impeller 20 is substantially disc-shaped, and numerous blades 20A are formed on its periphery by holes connecting both sides or recesses formed on both sides. The impeller 20 is connected to the pump shaft 34, and the pump shaft 34 is rotatably supported by the bearing holding portion 12E of the pump body 12 via a bearing 35.

[0027] As shown in Figure 1, the impeller 20 has multiple through holes 20B. These through holes 20B allow for pressure balance on both sides of the impeller 20. The multiple through holes 20B may be, for example, two or more, three or more, or four or more, and are arranged at equal angular intervals.

[0028] <Voltage boosting passage 12D and its surroundings> The booster passage 12D is formed between the pump body 12 and the impeller chamber cover 13, and extends along the peripheral edge of the impeller 20 blades 20A for a range of less than one full rotation. Specifically, it is formed by an impeller groove 12C formed in the pump body 12 and an impeller groove 13C formed in the impeller chamber cover 13. The pump body 12 has a liquid intake passage 12B connecting the liquid intake port 12A and the booster passage 12D, and the impeller chamber cover 13 has a liquid discharge passage 13B connecting the booster passage 12D and the liquid discharge port 13A. An O-ring 41 for sealing is also placed between the pump body 12 and the impeller chamber cover 13.

[0029] <Pump room 31 and its surroundings> The pump chamber 31 has an impeller chamber 32 and a rotor chamber 33, and is, for example, a cylindrical cavity. The pump chamber 31 houses the pump shaft 34, bearing 35, impeller 20, inner rotor 37, inner magnet 37A, etc. The bearing 35 is rotatably held by a bearing retaining portion 12E formed in the pump body 12. The pump shaft 34 is inserted through the bearing 35 and extends from the impeller chamber 32 to the rotor chamber 33 and is housed in the pump chamber 31.

[0030] The bearing retaining portion 12E is formed to protrude radially inward from the peripheral wall of the pump chamber 31, dividing the pump chamber 31 into an impeller chamber 32 and a rotor chamber 33. The rotor chamber 33 is formed in the rotor chamber cover 14, and the impeller chamber 32 is formed between the pump body 12 and the impeller chamber cover 13. The inner rotor 37 and inner magnet 37A are housed in the rotor chamber 33. The impeller 20 has its peripheral edge located in the boosting passage 12D, while the pump shaft 34 is inserted through its central portion and housed in the impeller chamber 32.

[0031] The pump chamber 31 is connected to the liquid inlet 12A, liquid inlet passage 12B, pressurization passage 12D, liquid discharge passage 13B, liquid discharge port 13A, etc. Multiple through holes 12F are provided around the bearing holder 12E, connecting the impeller chamber 32 and the rotor chamber 33. Through these through holes 12F and the through holes 20B formed in the impeller 20, the impeller chamber 32 and rotor chamber 33 within the pump chamber 31 are filled with the liquid to be pressurized.

[0032] <Electric motor 52 and its surroundings> As shown in Figure 1, the motor unit 50 consists of an electric motor 52, a motor housing 51, an outer rotor 53, an outer magnet 53A, etc. The electric motor 52 is the power source for rotating the impeller 20 and is fixed (fastened) to the rotor chamber cover 14 via the motor housing 51. The liquid pump 1 is controlled by a control device (not shown) electrically connected to the electric motor 52. The control device includes a processor and memory, and controls the liquid pump 1 by executing a control program stored in memory using the processor.

[0033] The pump shaft 34 is connected to the motor output shaft 52A of the electric motor 52 via a magnetic coupling from outside the pump housing 11. In one embodiment, the magnetic coupling is configured to connect an outer rotor 53 and outer magnet 53A with an inner rotor 37 and inner magnet 37A facing the outer rotor 53 using radial magnetic flux. For example, the outer rotor 53 is positioned on the outer circumference of the cup-shaped portion 14A of the rotor chamber cover 14, and the inner rotor 37 is positioned on the inner circumference of the cup-shaped portion 14A. The outer rotor 53 is a cylindrical body equipped with a plurality of outer magnets 53A and is connected to the motor output shaft 52A of the electric motor 52. The inner rotor 37 is equipped with a plurality of inner magnets 37A and is connected to the pump shaft 34. In another embodiment (not shown), two facing disks may be connected with axial magnetic flux to constitute the magnetic coupling.

[0034] In the above embodiment, the electric motor 52 is fixed (fastened) to the outside of the pump housing 11 via the motor housing 51. However, in another embodiment (not shown), it is also possible to house both the electric motor and the pump unit within the same housing. In such an embodiment, when transferring corrosive liquids such as liquefied ammonia or high-pressure liquids, the electric motor may be separated from the inside of the pump unit (pressure boosting passage 12D or pump chamber 31) by a partition wall similar to the cup-shaped portion 14A of the rotor chamber cover 14 so as not to communicate with the inside of the pump unit. In this case, the torque from the electric motor is transmitted to the pump shaft via a magnetic coupling similar to the above, with the partition wall in between.

[0035] <Pump operation> When the impeller 20 rotates due to the drive of the electric motor 52 with the pump chamber 31 filled with liquid, the liquid to be pressurized is drawn in from the liquid inlet 12A through the liquid inlet passage 12B. The drawn-in liquid gains energy in the pressurization passage 12D and is then discharged from the liquid discharge passage 13B through the liquid discharge port 13A. Since the pump chamber 31 is filled with liquid while the liquid pump 1 is in operation, the bearing 35 is immersed in the liquid. When the area around the bearing 35 is filled with liquid, the viscosity of the liquid is higher than the viscosity of the gas, so wear due to dry sliding is avoided.

[0036] During operation of the liquid pump 1, heat generated by the electric motor 52 is transferred from the electric motor 52 to the pump chamber 31 via the heat conduction path N shown by the dotted line in Figure 1, and a portion of the liquid in the pump chamber 31 may vaporize and turn into a gas. When a portion of the liquid in the pump chamber 31 vaporizes and turns into a gas, the viscosity of the gas is lower than that of the liquid, so the lubricating oil film on the bearing 35 becomes thinner, which can lead to so-called dry sliding and accelerate wear.

[0037] <Cooling passage 43 and its surroundings> The cooling passage 43 is not located on the outer periphery of the electric motor 52, but is provided in the heat conduction path N from the electric motor 52 to the pump chamber 31, through which the refrigerant flows, suppressing the transfer of heat from the electric motor 52 to the pump chamber 31. Furthermore, since the cooling passage 43 is not located on the outer periphery of the electric motor 52, it is possible to avoid increasing the size of the motor unit 50.

[0038] The pump section 10 has a pump body 12 (corresponding to the first pump chamber forming member) in which a part of the pump chamber 31 is formed and which has a first mounting surface 12M (see Figure 2). The pump section 10 also has a rotor chamber cover 14 (corresponding to the second pump chamber forming member) in which a part of the pump chamber 31 is formed at a different location from the part of the pump chamber 31 formed in the pump body 12 and which has a second mounting surface 14M that is in contact with the first mounting surface 12M.

[0039] The cooling passage 43 is a groove provided on at least one of the first mounting surface 12M and the second mounting surface 14M. Figures 1 to 4 show an example in which the cooling passage 43 is provided on the first mounting surface 12M. In the example in Figures 1 to 3, an O-ring groove 12X for holding O-ring 42A is provided on the innermost side, and an O-ring groove 12Y for holding O-ring 42B is provided on the outer circumference side of O-ring groove 12X. A cooling passage 43 is provided on the outer circumference side of O-ring groove 12Y, and an O-ring groove 12Z for holding O-ring 42C is provided on the outer circumference side of the cooling passage 43. As shown in Figure 1, O-rings 42A, 42B, and 42C for sealing are arranged between the pump body 12 and the rotor chamber cover 14. Furthermore, as shown in Figure 3, a bolt hole H1 for bolt B1 (see Figure 1) is formed between O-ring groove 12X and O-ring groove 12Y, and a bolt hole H2 for bolt B2 (see Figure 1) is formed on the outer circumference of O-ring groove 12Z.

[0040] Figure 3 is a view of the pump body 12 shown in Figure 2 from direction III. Note that the pump body 12 shown in Figure 3 omits details such as the liquid intake passage 12B. The cooling passage 43 is an annular groove formed in the first mounting surface 12M, as shown in Figure 3, and is connected to the refrigerant inlet 44A through which refrigerant K flows in, via the refrigerant intake passage 44B, as shown in Figure 1. The cooling passage 43 is also connected to the refrigerant outlet 45A through which refrigerant K flows out, via the refrigerant discharge passage 45B, as shown in Figure 1. Various refrigerants can flow through the cooling passage 43, but the same liquid as the one being pressurized can also be used as the refrigerant. Cooling piping (not shown) is connected to the refrigerant inlet 44A, and refrigerant (for example, the same liquid as the one being pressurized) is guided to the refrigerant inlet 44A.

[0041] If the liquid to be pressurized is volatile, it is undesirable for heat from the electric motor 52 to be transferred to the pump chamber 31. If a volatile liquid is used as a refrigerant and supplied to the cooling passage 43 from a cooling path separate from the pressurization path, at least a portion of the liquid (refrigerant) will vaporize in the cooling passage 43, and its latent heat of vaporization will absorb heat from the surroundings, thus allowing for efficient cooling.

[0042] Figure 4 is an enlarged view of section AA in Figure 2 and shows another embodiment of the cooling passage 43. To further improve cooling efficiency, one or more circumferentially extending cooling fins 43A may be provided within the cooling passage 43, as shown in Figure 4, or the cooling passage 43 may be composed of multiple grooves 43B. Furthermore, as shown in Figure 3, providing a refrigerant discharge passage 45B above the cooling passage 43 is convenient because it allows the vaporized liquid (refrigerant) to be efficiently discharged from the refrigerant discharge port 45A.

[0043] <Example of a system using liquid pump 1 (Figure 5)> Figure 5 shows an example of applying the liquid pump 1 to the combustion system 80. The combustion system 80 includes the liquid pump 1, fuel tank 81, evaporator 82, gas compressor 83, turbine combustion chamber 84, generator 85, control device 86, etc.

[0044] The fuel tank 81 stores a volatile liquid (liquid fuel, such as liquid ammonia). The liquid pump 1 is the liquid pump described above. The evaporator 82 is a device that evaporates liquid fuel (or a mixture of liquid fuel and gaseous fuel) to convert it into gaseous fuel. The gas compressor 83 is a device that pumps gaseous fuel. The turbine combustion chamber 84 is a combustion device that uses liquid fuel and gaseous fuel obtained by evaporating liquid fuel as fuel. The generator 85 is a device that generates electricity driven by a turbine located in the turbine combustion chamber 84. The control device 86 detects the operating status of the fuel tank 81, evaporator 82, gas compressor 83, and turbine combustion chamber 84, and adjusts the opening degree of each shut-off valve 89A to 89C and each solenoid valve 88A to 88H.

[0045] The liquid fuel supply passages 87A and 87B are passages that supply liquid fuel to the turbine combustion chamber 84 by pressurizing the liquid fuel in the fuel tank 81 using the liquid pump 1. The upstream side of liquid fuel supply passage 87A is connected to the fuel tank 81, and the downstream side of liquid fuel supply passage 87A is connected to the liquid intake port 12A of the liquid pump 1. Liquid fuel supply passage 87A is equipped with a shut-off valve 89A (solenoid valve) on the fuel tank 81 side and a solenoid valve 88A on the liquid pump 1 side. The upstream side of liquid fuel supply passage 87B is connected to the liquid discharge port 13A of the liquid pump 1, and the downstream side of liquid fuel supply passage 87B is connected to the turbine combustion chamber 84. Liquid fuel supply passage 87B is equipped with a solenoid valve 88B on the liquid pump 1 side and a shut-off valve 89B (solenoid valve) on the turbine combustion chamber 84 side.

[0046] The gaseous fuel supply passages 87E, 87F, and 87G are passages that convert liquid fuel in the fuel tank 81 into gaseous fuel in the evaporator 82, and then supply the gaseous fuel to the turbine combustion chamber 84 by pressurizing it with a gas compressor 83. The upstream side of the gaseous fuel supply passage 87E is connected to the liquid fuel supply passage 87A between the shut-off valve 89A and the solenoid valve 88A, and the downstream side of the gaseous fuel supply passage 87E is connected to the inlet of the evaporator 82. The gaseous fuel supply passage 87E is equipped with a solenoid valve 88F on the side of the evaporator 82. The upstream side of the gaseous fuel supply passage 87F is connected to the outlet of the evaporator 82, and the downstream side of the gaseous fuel supply passage 87F is connected to the inlet of the gas compressor 83. The gaseous fuel supply passage 87F is equipped with a solenoid valve 88G. The upstream side of the gaseous fuel supply passage 87G is connected to the discharge port of the gas compressor 83, and the downstream side of the gaseous fuel supply passage 87G is connected to the turbine combustion chamber 84. The gaseous fuel supply passage 87G is equipped with a solenoid valve 88H on the gas compressor 83 side and a shut-off valve 89C (solenoid valve) on the turbine combustion chamber 84 side.

[0047] Branch passages 87C and 87D branch off from the liquid fuel supply passage 87A and supply liquid fuel from the fuel tank 81 to the cooling passage 43 of the liquid pump 1 (see Figures 1 to 3), and supply the fuel mixture of liquid fuel and gaseous fuel used for cooling to the evaporator 82. The upstream side of branch passage 87C is connected to the liquid fuel supply passage 87A between the shut-off valve 89A and the solenoid valve 88A, and the downstream side of branch passage 87C is connected to the refrigerant inlet 44A of the liquid pump 1. A solenoid valve 88C is provided on the liquid pump 1 side of branch passage 87C. The upstream side of branch passage 87D is connected to the refrigerant discharge port 45A of the liquid pump 1, and the downstream side of branch passage 87D is connected to the inlet of the evaporator 82. A solenoid valve 88D is provided on the liquid pump 1 side of branch passage 87D, and a solenoid valve 88E is provided on the evaporator 82 side.

[0048] Shut-off valve 89A is a valve capable of shutting off the liquid fuel supplied from the fuel tank 81, shut-off valve 89B is a valve capable of shutting off the liquid fuel supplied to the turbine combustion chamber 84, and shut-off valve 89C is a valve capable of shutting off the gaseous fuel supplied to the turbine combustion chamber 84.

[0049] Solenoid valves 88A, 88B, 88C, and 88D are valves that can shut off the passage during maintenance or replacement of liquid pump 1, and allow adjustment of the passage opening during normal operation. Solenoid valves 88E, 88F, and 88G are valves that can shut off the passage during maintenance or replacement of evaporator 82, and allow adjustment of the passage opening during normal operation. Solenoid valves 88G and 88H are valves that can shut off the passage during maintenance or replacement of gas compressor 83, and allow adjustment of the passage opening during normal operation. Note that solenoid valves 88A to 88H are optional.

[0050] <Effects, etc.> As described above, in the technology disclosed herein, as shown in Figure 1, the cooling passage 43 of the liquid pump 1 is not located on the outer circumference of the electric motor 52, but is located in the heat conduction path N from the electric motor 52 to the pump chamber 31. Therefore, vaporization of the liquid in the pump chamber 31 can be suppressed, and the size of the product can be kept from increasing. Furthermore, by suppressing vaporization, deterioration of the lubricity of the pump sliding parts can be suppressed. In addition, when a volatile liquid fuel is used as a refrigerant, a greater cooling effect can be obtained due to the latent heat of vaporization.

[0051] Furthermore, in the combustion system 80 shown in Figure 5, since the liquid in the fuel tank 81 is a volatile liquid fuel, the liquid fuel (refrigerant) flowing through the cooling passage 43 of the liquid pump 1 (see Figures 1 to 3) easily vaporizes. Therefore, a large cooling effect can be obtained from the latent heat of vaporization when the liquid fuel vaporizes. Moreover, the mixture of liquid fuel and gaseous fuel used for cooling is led to the evaporator 82 and used as gaseous fuel, so there is no waste.

[0052] <Other> The liquid pump 1 and the combustion system 80 using the liquid pump 1 disclosed herein are not limited to the configuration, structure, appearance, shape, etc. described in this embodiment, and various modifications, additions, and deletions are possible as long as they do not alter the essence of the disclosed technology.

[0053] In this embodiment, the liquid pump 1 described uses liquid ammonia as an example of the volatile liquid to be pressurized, but the volatile liquid to be pressurized is not limited to liquid ammonia, and can be used to pressurize and transfer various volatile liquids. Also, although liquid ammonia was used as an example of the refrigerant flowing through the cooling passage 43, the refrigerant is not limited to liquid ammonia, and various fluids can be used as refrigerants. Furthermore, the liquid pump 1 is not limited to application to the combustion system 80 (see Figure 5), but can be applied to various systems that pressurize and transfer volatile liquids.

[0054] In this embodiment, the liquid pump 1 described is an example in which a cooling passage 43 is provided on the first mounting surface 12M, but the cooling passage 43 only needs to be provided on at least one of the first mounting surface 12M and the second mounting surface 14M. [Explanation of Symbols]

[0055] 1. Liquid pump 10 Pump section 11 Pump Housing 12 Pump body (first pump chamber forming member) 12A liquid inlet 12B Liquid suction passage 12C, 13C Impeller Groove 12D Booster Passage 12E Bearing Retaining Section 12F through hole 12M First mounting surface 12X, 12Y, 12Z O-ring grooves 13 Impeller chamber cover 13A Liquid outlet 13B Liquid discharge passage 14. Rotor chamber cover (second pump chamber forming member) 14A Cup-shaped section 14M Second mounting surface 20 Impellers 20A blade 20B through hole 31 Pump Room 32 Impeller Chamber 33 Rotor chamber 34 Pump shaft 34Z center axis 35 Bearings 37 Inner Rotor 37A Inner Magnet 41 O-rings 42A, 42B, 42C O-rings 43 Cooling passage 43A Cooling Fins 44A Refrigerant intake 44B Refrigerant intake passage 45A Refrigerant outlet 45B Refrigerant discharge passage 50 Motor section 51 Motor Housing 52 Electric motor 52A motor output shaft 53 Outer rotor 53A Outer Magnet 80 Combustion System 81 Fuel Tank 82 Evaporator 83 Gas Compressor 84. Turbine combustion chamber (combustion device) 85 Generators 86 Control device 87A, 87B Liquid fuel supply passage 87C, 87D branching passage 87E, 87F, 87G Gas fuel supply passages 88A~88H Solenoid valves 89A~89C Shut-off valves B1, B2 bolts H1, H2 bolt holes K refrigerant L liquid N heat conduction path

Claims

1. A liquid pump that pressurizes a liquid, The aforementioned liquid is volatile, A pump unit having a pump chamber filled with the aforementioned liquid, which pressurizes and discharges the liquid in the pump chamber, A motor unit having an electric motor that drives the pump unit and being fastened to the pump unit, A cooling passage is provided in the heat conduction path from the electric motor to the pump chamber, not on the outer circumference of the electric motor, through which the refrigerant flows. Having, Liquid pump.

2. A liquid pump according to claim 1, The aforementioned pump section is A first pump chamber forming member having a part of the pump chamber and a first mounting surface, A second pump chamber forming member has a portion of the pump chamber formed in a location different from the portion of the pump chamber formed in the first pump chamber forming member, and has a second mounting surface that contacts the first mounting surface, It has, The cooling passage is a groove formed in at least one of the first mounting surface and the second mounting surface. Liquid pump.

3. A liquid pump according to claim 1 or 2, A booster pipe is connected to the liquid inlet that communicates with the pump chamber, and the liquid is guided through it. Cooling piping is connected to the refrigerant inlet that communicates with the cooling passage, and the liquid is guided through it. Liquid pump.

4. A combustion system having a liquid pump according to claim 1 or 2, A fuel tank in which the aforementioned liquid is stored, A combustion device that uses the aforementioned liquid fuel and the gaseous fuel obtained by evaporating the aforementioned liquid as fuel, A liquid fuel supply passage connected from the fuel tank to the combustion device, the liquid fuel supply passage being provided with a liquid pump that pressurizes the liquid fuel in the pump section and supplies it to the combustion device, A gaseous fuel supply passage connected from the fuel tank to the combustion device, the gaseous fuel supply passage being provided with an evaporator for evaporating the liquid and supplying the gaseous fuel to the combustion device, A branch passage that branches off from the liquid fuel supply passage and is connected to the evaporator via the cooling passage of the liquid pump, Having, Combustion system.

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