Gas supply device and starting method for gas supply device

Abstract

To improve energy efficiency of a whole device.SOLUTION: A gas supply device 20 for supplying gas to a heat engine 10 comprises a low-pressure compressor 21 for compressing supply gas that is gas to be supplied to the heat engine 10, a heat exchanger 22 into which the supply gas compressed by the low-pressure compressor 21 is introduced, a high-pressure compressor 23 for compressing the supply gas heat-exchanged by the heat exchanger 22, a high-pressure air supply pipe 33 for supplying the supply gas compressed by the high-pressure compressor 23, to the heat engine 10, and a high-pressure air exhaust pipe 34 and a first low-pressure air exhaust pipe 35 for guiding exhaust gas that is gas exhausted from the heat engine 10, to the heat exchanger 22. The heat exchanger 22 cools the supply gas by exchanging heat between the supply gas and the exhaust gas.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a gas supply device and a method for starting the gas supply device.

Background Art

[0002] A gas supply device that supplies high-temperature gas to a heat engine that performs work using heat includes a compressor that compresses the gas to be supplied to the heat engine. In such a gas supply device, when performing compression with a high compression ratio, it is known to provide a plurality of compressors and compress the gas while cooling the gas at an intermediate stage between the compressors (for example, Patent Document 1). Patent Document 1 describes a regeneration engine that includes a low-pressure compressor that takes in working gas from the atmosphere through a compressor inlet duct, and the outlet of the low-pressure compressor is connected to the inlet of a high-pressure compressor through an intermediate compressor cooler.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As a device for cooling gas at an intermediate stage, it is known to use a compact heat exchanger using cooling water or the like. By using such a heat exchanger, it is possible to reduce the power of the compressor and make the equipment more compact, thereby reducing costs. However, when a gas supply device with such a structure is applied to a heat engine, since part of the heat is discarded outside the system through the cooling water, there is a possibility that it may cause a decrease in the energy efficiency of the entire device.

[0005] The present disclosure has been made in view of such circumstances, and an object thereof is to provide a gas supply device capable of improving the energy efficiency of the entire device and a method for starting the gas supply device.

Means for Solving the Problems

[0006] In order to solve the above problems, the gas supply device and the method for starting the gas supply device of the present disclosure employ the following means. A gas supply device according to one aspect of the present disclosure is a gas supply device that supplies gas to a heat engine, and includes a first compressor that compresses supply gas, which is gas supplied to the heat engine; a heat exchanger into which the supply gas compressed by the first compressor is introduced; a second compressor that compresses the supply gas that has undergone heat exchange in the heat exchanger; a first supply unit that supplies the supply gas compressed by the second compressor to the heat engine; and a first discharge unit that guides exhaust gas, which is gas discharged from the heat engine, to the heat exchanger. The heat exchanger cools the supply gas by performing heat exchange between the supply gas and the exhaust gas.

[0007] Moreover, a method for starting a gas supply device according to an aspect of the present disclosure is a method for starting a gas supply device that supplies gas to a heat engine. The gas supply device includes a first compressor that compresses supply gas, which is the gas supplied to the heat engine, a heat exchanger into which the supply gas compressed by the first compressor is introduced, a second compressor that compresses the supply gas that has undergone heat exchange in the heat exchanger, a first supply unit that supplies the supply gas compressed by the second compressor to the heat engine, a first discharge unit that guides exhaust gas, which is the gas discharged from the heat engine, to the heat exchanger, a second supply unit that supplies the supply gas to the heat exchanger, a second discharge unit from which the exhaust gas heated by undergoing heat exchange in the heat exchanger is discharged, a first expander that is connected to the second discharge unit and recovers the heat of the exhaust gas discharged from the heat exchanger and expands the exhaust gas, a first connection unit that connects the second supply unit and the second discharge unit, and a flow rate adjustment valve that adjusts the flow rate of the gas flowing through the first connection unit. The heat exchanger cools the supply gas by performing heat exchange between the supply gas and the exhaust gas, and includes a compressor starting step of starting the first compressor and a flow rate adjustment valve opening step of changing the flow rate adjustment valve from a closed state to an open state.

Effects of the Invention

[0008] According to the present disclosure, the energy efficiency of the entire device can be improved.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0010] Hereinafter, an embodiment of a gas supply device and a method for starting the gas supply device according to the present disclosure will be described with reference to the drawings. 〔First Embodiment〕 Hereinafter, a first embodiment of the present disclosure will be described with reference to FIG. 1. The gas supply device 20 according to the present embodiment is a device that supplies high-temperature and high-pressure air to the heat engine 10. The heat engine according to the present embodiment is an engine that obtains electric energy or kinetic energy using heat and has functions of air supply and exhaust. Examples of the heat engine according to the present embodiment include a solid oxide electrolysis cell (SOEC), an engine, and the like.

[0011] An SOEC is supplied with an oxidizing gas (in this embodiment, air as an example) at high temperature and high pressure and high-temperature and high-pressure steam. The oxidizing gas and steam supplied to the SOEC are led into the reaction chamber. The SOEC generates hydrogen by electrolyzing steam using a high-temperature solid electrolyte in the reaction chamber. For example, ceramics such as yttria-stabilized zirconia are used as the electrolyte in the SOEC, and hydrogen can be produced with high efficiency because high-temperature steam is used as a raw material compared to other electrolysis cells.

[0012] For example, when the heat engine 10 to which air is supplied is an SOEC, the gas supply device 20 supplies an oxidizing gas to the reaction chamber of the SOEC. Further, for example, when the heat engine 10 to which air is supplied is an engine, the gas supply device 20 supplies combustion air to the engine.

[0013] The gas supply device 20 includes a low-pressure compressor (first compressor) 21, a heat exchanger 22, and a high-pressure compressor (second compressor) 23. The gas supply device 20 also includes a high-pressure expander (heat recovery unit) 24 and a low-pressure expander (heat recovery unit) 25.

[0014] The low-pressure compressor 21 compresses the supplied air and discharges the compressed air. The low-pressure compressor 21 is driven by the driving force from the electric motor 27. The low-pressure compressor 21 is connected to the low-pressure expander 25. Also, the low-pressure expander 25 expands the supplied air and discharges the expanded air. The low-pressure expander 25 drives the low-pressure compressor 21 by the force of the expanding air. That is, the low-pressure expander 25 recovers the heat of the air and uses the recovered heat for driving the low-pressure compressor 21. Thus, the low-pressure compressor 21 is driven not only by the driving force of the electric motor 27 but also by the driving force from the low-pressure expander 25.

[0015] The high-pressure compressor 23 compresses the supplied air and discharges the compressed air. The high-pressure compressor 23 is driven by the driving force from the electric motor 28. The high-pressure compressor 23 is connected to the high-pressure expander 24. Also, the high-pressure expander 24 expands the supplied air and discharges the expanded air. The high-pressure expander 24 drives the high-pressure compressor 23 by the force of the expanding air. That is, the high-pressure expander 24 recovers the heat of the air and uses the recovered heat for driving the high-pressure compressor 23. Thus, the high-pressure compressor 23 is driven not only by the driving force of the electric motor 28 but also by the driving force from the high-pressure expander 24.

[0016] Note that the low-pressure compressor 21 and the high-pressure compressor 23 may be of any type as long as they can withstand a predetermined temperature (for example, about 400 °C) and can compress air. The low-pressure compressor 21 and the high-pressure compressor 23 may be, for example, axial flow type, reciprocating type, or screw type.

[0017] The heat exchanger 22 exchanges heat between the air compressed by the low-pressure compressor 21 and the air expanded by the high-pressure expander 24. The heat exchanger 22 may be, for example, a regenerative rotary heat exchanger. By using a regenerative rotary heat exchanger, heat exchange between fluids with a large temperature difference can be suitably performed. Note that the type of the heat exchanger 22 is not limited to the regenerative rotary type. For example, it may be a plate type heat exchanger or a shell and tube type heat exchanger.

[0018] Further, the gas supply device 20 includes an air supply pipe 30 that supplies air to the low-pressure compressor 21, a first low-pressure air supply pipe (second supply unit) 31 that connects the low-pressure compressor 21 and the heat exchanger 22, a second low-pressure air supply pipe 32 that connects the heat exchanger 22 and the high-pressure compressor 23, and a high-pressure air supply pipe (first supply unit) 33 that connects the high-pressure compressor 23 and the heat engine 10. The first low-pressure air supply pipe 31 is provided with a first low-pressure air supply valve 31a that can adjust the amount of air flowing through the inside by adjusting the opening degree. The high-pressure air supply pipe 33 is provided with a high-pressure air supply valve 33a that can adjust the amount of air flowing through the inside by adjusting the opening degree.

[0019] Further, the gas supply device 20 includes a high-pressure air discharge pipe (first discharge unit) 34 that connects the heat engine 10 and the high-pressure expander 24, a first low-pressure air discharge pipe 35 that connects the high-pressure expander 24 and the heat exchanger 22, a second low-pressure air discharge pipe (second discharge unit) 36 that connects the heat exchanger 22 and the low-pressure expander 25, and an air discharge pipe 37 that discharges air from the low-pressure expander 25. The high-pressure air discharge pipe (first discharge unit) 34 is provided with a high-pressure air discharge valve 34a that can adjust the amount of air flowing through the inside by adjusting the opening degree. The second low-pressure air discharge pipe 36 is provided with a second low-pressure air discharge valve 36a that can adjust the amount of air flowing through the inside by adjusting the opening degree.

[0020] Further, the gas supply device 20 includes a high-pressure connection pipe (second connection part) 38 that connects the high-pressure air supply pipe 33 and the high-pressure air discharge pipe 34, and a low-pressure connection pipe (first connection part) 39 that connects the first low-pressure air supply pipe 31 and the second low-pressure air discharge pipe 36.

[0021] One end of the high-pressure connection pipe 38 is connected to the upstream side of the high-pressure air supply valve 33a in the high-pressure air supply pipe 33. Also, the other end of the high-pressure connection pipe 38 is connected to the downstream side of the high-pressure air discharge valve 34a in the high-pressure air discharge pipe 34. One end of the low-pressure connection pipe 39 is connected to the upstream side of the first low-pressure air supply valve 31a in the first low-pressure air supply pipe 31. Also, the other end of the low-pressure connection pipe 39 is connected to the downstream side of the second low-pressure air discharge valve 36a in the second low-pressure air discharge pipe 36.

[0022] The high-pressure connection pipe 38 is provided with a high-pressure connection valve (second flow rate adjustment part) 38a that can adjust the amount of air flowing through the inside by adjusting the opening degree. The low-pressure connection pipe 39 is provided with a low-pressure connection valve (first flow rate adjustment part, flow rate adjustment valve) 39a that can adjust the amount of air flowing through the inside by adjusting the opening degree.

[0023] The first low-pressure air supply valve 31a, the high-pressure air supply valve 33a, the high-pressure air discharge valve 34a, the second low-pressure air discharge valve 36a, the high-pressure connection valve 38a, and the low-pressure connection valve 39a are, for example, electric valves driven by an electric motor (not shown) provided in each valve. The drive source of each valve is not limited to an electric motor, and an air cylinder or the like may be used.

[0024] Next, an example of the flow of the fluid flowing through the gas supply device 20 during normal operation of the gas supply device 20 will be described. Hereinafter, an example in which an SOEC is adopted as the heat engine 10 will be described.

[0025] The air supplied to the low-pressure compressor 21 through the air supply pipe 30 is compressed in the low-pressure compressor 21.

[0026] The air supplied to the low-pressure compressor 21 is heated and pressurized and then discharged to the first low-pressure air supply pipe 31. The air discharged from the low-pressure compressor 21 is supplied to the heat exchanger 22 via the first low-pressure air supply pipe 31.

[0027] The air supplied to the heat exchanger 22 is cooled in the heat exchanger 22 by exchanging heat with the air discharged from the heat engine 10 and cooled and depressurized by the high-pressure expander 24. The air cooled by the heat exchanger 22 is discharged to the second low-pressure air supply pipe 32. The air discharged from the heat exchanger 22 is supplied to the high-pressure compressor 23 via the second low-pressure air supply pipe 32. The air supplied to the high-pressure compressor 23 via the second low-pressure air supply pipe 32 is compressed in the high-pressure compressor 23.

[0028] The air supplied to the high-pressure compressor 23 is heated and pressurized and then discharged to the high-pressure air supply pipe 33. The air discharged from the high-pressure compressor 23 is supplied to the SOEC via the high-pressure air supply pipe 33.

[0029] The air supplied to the SOEC is used for the electrolysis of water vapor in the reaction chamber. The air used for electrolysis is discharged from the SOEC to the high-pressure air discharge pipe 34 together with the oxygen generated in the reaction chamber. The mixture of air and oxygen discharged from the SOEC (hereinafter referred to as "discharge air") is supplied to the high-pressure expander 24 via the high-pressure air discharge pipe 34. The discharge air supplied to the high-pressure expander 24 is used as a driving source for the high-pressure compressor 23 in the high-pressure expander 24 and is depressurized and cooled.

[0030] The air supplied to the high-pressure expander 24 is depressurized and cooled and then discharged to the first low-pressure air discharge pipe 35. The air discharged from the high-pressure expander 24 is supplied to the heat exchanger 22 via the first low-pressure air discharge pipe 35.

[0031] The air supplied to the heat exchanger 22 is heated in the heat exchanger 22 by exchanging heat with the air supplied to the heat engine 10. The air heated by the heat exchanger 22 is discharged to the second low-pressure air discharge pipe 36. The air discharged from the heat exchanger 22 is supplied to the low-pressure expander 25 via the second low-pressure air discharge pipe 36. The air supplied to the low-pressure expander 25 via the second low-pressure air discharge pipe 36 is utilized as a driving source for the low-pressure compressor 21 in the low-pressure expander 25, and is depressurized and cooled.

[0032] The air discharged from the low-pressure expander 25 is discharged to the outside of the system via the air discharge pipe 37.

[0033] Next, a method for starting the fluid supply device will be described. First, as a first step, all of the first low-pressure air supply valve 31a, high-pressure air supply valve 33a, high-pressure air discharge valve 34a, second low-pressure air discharge valve 36a, high-pressure connection valve 38a, and low-pressure connection valve 39a are closed.

[0034] Next, as a second step, the low-pressure compressor 21 is started and at the same time the low-pressure connection valve 39a is opened. At this time, the inlet valve (not shown) provided at the inlet of the low-pressure compressor 21 is throttled, or the motor speed of the electric motor 27 is set to a low speed, and the low-pressure compressor 21 is started with the minimum power. Thereby, the air discharged from the low-pressure compressor 21 is introduced into the low-pressure expander 25 via the low-pressure connection pipe 39.

[0035] When a certain amount of air is introduced into the low-pressure expander 25, next, as a third step, the first low-pressure air supply valve 31a and the second low-pressure air discharge valve 36a are opened. Thereby, air is introduced into the high-pressure compressor 23 and the high-pressure expander 24. The high-pressure compressor 23 system is pressurized up to the outlet pressure of the low-pressure compressor 21.

[0036] Next, as a fourth step, the opening degree of the low-pressure connection pipe 39 is adjusted to a degree slightly reduced from the fully open state. As a result, the outlet pressure of the low-pressure compressor 21 becomes higher than the inlet pressure of the low-pressure expander 25.

[0037] Next, as a fifth step, the high-pressure compressor 23 is started and at the same time the high-pressure connection valve 38a is slightly opened. At this time, the inlet valve (not shown) provided at the inlet of the high-pressure compressor 23 is throttled, or the motor rotation speed of the electric motor 28 is set to a low rotation speed to start the high-pressure compressor 23 with the minimum power.

[0038] Next, as a sixth step, the opening degree of the high-pressure connection valve 38a is gradually increased. At this time, as the opening degree of the high-pressure connection valve 38a is increased, the opening degree of the low-pressure connection valve 39a is decreased. Finally, the low-pressure connection valve 39a is fully closed.

[0039] Next, as a seventh step, the high-pressure air supply valve 33a and the high-pressure air discharge valve 34a are opened. When valves corresponding to the high-pressure air supply valve 33a and the high-pressure air discharge valve 34a are provided in the heat engine 10, the valves provided in the heat engine 10 may be used instead of the high-pressure air supply valve 33a and the high-pressure air discharge valve 34a.

[0040] Next, as an eighth step, the high-pressure connection valve 38a is closed according to the demand on the heat engine 10 side. When the high-pressure connection valve 38a is fully closed, the startup of the gas supply device 20 is completed. In this embodiment, the gas supply device 20 is started in this manner.

[0041] According to this embodiment, the following operational effects are achieved. In this embodiment, the heat exchanger 22 cools the supply air by performing heat exchange between the supply air (the air supplied to the heat engine 10) and the exhaust air (the air discharged from the heat engine 10). As a result, the exhaust air discharged from the first discharge portion can be used to cool the supply air between the low-pressure compressor 21 and the high-pressure compressor 23. Therefore, the energy efficiency of the entire apparatus can be improved as compared with the case of using a refrigerant (for example, cooling water) for separately cooling the supply air.

[0042] In this embodiment, a high-pressure expander 24 and a low-pressure expander 25 for recovering the heat of the exhaust air discharged from the heat engine 10 are provided. Thereby, the heat of the exhaust air can be recovered. Therefore, when the recovered heat is used in the apparatus, the energy efficiency of the entire apparatus can be improved.

[0043] Further, in this embodiment, by recovering the heat of the exhaust air with the high-pressure expander 24, the temperature of the exhaust air can be adjusted. Therefore, the temperature of the exhaust air introduced into the heat exchanger 22 can be set to an appropriate temperature, so that the supply air, which is the heat exchange partner in the heat exchanger 22, can be suitably cooled.

[0044] Further, in this embodiment, the low-pressure expander 25 is connected to the low-pressure compressor 21, and drives the connected low-pressure compressor 21 by the force of expanding the exhaust air. Also, the high-pressure expander 24 is connected to the high-pressure compressor 23, and drives the connected high-pressure compressor 23 by the force of expanding the exhaust air. Thereby, the low-pressure compressor 21 and the high-pressure compressor 23 can be driven using the heat of the exhaust air. Therefore, the energy efficiency of the entire apparatus can be improved.

[0045] Also, in this embodiment, a low-pressure connection pipe 39 is provided. As a result, when gas is supplied to the low-pressure compressor 21 at the time of starting the gas supply device 20, the gas discharged from the low-pressure compressor 21 can be supplied to the low-pressure expander 25 via the low-pressure connection pipe 39. The low-pressure expander 25 drives the low-pressure compressor 21 by expanding the gas. Therefore, at the time of starting the gas supply device 20, the low-pressure compressor 21 can be driven using the driving force of the low-pressure expander 25. Therefore, the required driving force of the electric motor 27 for driving the low-pressure compressor 21 can be reduced. Therefore, the electric motor 27 can be miniaturized. Therefore, the entire gas supply device 20 can be miniaturized, and the initial cost can be reduced.

[0046] Also, in this embodiment, a high-pressure connection pipe 38 is provided. As a result, when gas is supplied to the high-pressure compressor 23 at the time of starting the gas supply device 20, the gas discharged from the high-pressure compressor 23 can be supplied to the high-pressure expander 24. The high-pressure expander 24 drives the high-pressure compressor 23 by expanding the gas. Therefore, at the time of starting the gas supply device 20, the high-pressure compressor 23 can be driven using the driving force of the high-pressure expander 24. Therefore, the required driving force of the electric motor 28 for driving the high-pressure compressor 23 can be reduced. Therefore, the electric motor 28 can be miniaturized. Therefore, the entire gas supply device 20 can be miniaturized, and the initial cost can be reduced.

[0047] Also, in the balance of the pressure and temperature of the exhaust air discharged from the heat engine 10, when the pressure is high, if all the pressure is recovered by the high-pressure expander 24 (if the pressure difference between the inlet and the outlet is made too large), the temperature of the exhaust air may become excessively low. When the temperature of the exhaust air becomes excessively low, if the exhaust air contains moisture, condensation or freezing may occur in the low-pressure expander 25 provided on the downstream side, and there may be a problem that the temperature and pressure cannot be sufficiently recovered by the low-pressure expander 25. On the other hand, in the present embodiment, a heat exchanger 22 is provided between the high-pressure expander 24 and the low-pressure expander 25, and the exhaust air is heated in the heat exchanger 22. Therefore, the occurrence of condensation and freezing in the low-pressure expander 25 can be suppressed. Thus, the temperature and pressure can be sufficiently recovered by the low-pressure expander 25.

[0048] 〔Second Embodiment〕 Next, the second embodiment of the present disclosure will be described with reference to FIG. 2. In this embodiment, it is different from the first embodiment in that a supply-side bypass pipe (supply-side bypass portion) 41 and a discharge-side bypass pipe (discharge-side bypass portion) 42 are provided so as to bypass the heat exchanger 22. Further, it is different from the first embodiment in that a temperature adjustment unit 43 is provided in the second low-pressure air supply pipe 32. Since other configurations are substantially the same as those of the first embodiment, the same reference numerals are given to the same configurations and the detailed description thereof is omitted.

[0049] The air supply device 40 according to the present embodiment includes a supply-side bypass pipe 41 that guides the air compressed by the low-pressure compressor 21 to the high-pressure compressor 23 so as to bypass the heat exchanger 22. The supply-side bypass pipe 41 connects the first low-pressure air supply pipe 31 and the second low-pressure air supply pipe 32. Further, the supply-side bypass pipe 41 is provided with a supply-side bypass valve 41a that adjusts the amount of air flowing through the inside by adjusting the opening degree.

[0050] Note that the second low-pressure air supply pipe 32 may be provided with a second low-pressure air supply valve 32a that adjusts the amount of air flowing through the inside by adjusting the opening degree. In this case, the downstream end of the supply-side bypass pipe 41 is connected to the upstream side of the second low-pressure air supply valve 32a. Further, the air supply pipe 30 may also be provided with an air supply valve 30a that adjusts the amount of air flowing through the inside by adjusting the opening degree.

[0051] The air supply device 40 according to this embodiment includes a discharge side bypass pipe 42 that guides the air expanded by the high-pressure expander 24 to the low-pressure expander 25 so as to bypass the heat exchanger 22. The discharge side bypass pipe 42 connects the first low-pressure air discharge pipe 35 and the second low-pressure air discharge pipe 36. Further, the discharge side bypass pipe 42 is provided with a discharge side bypass valve 42a that adjusts the amount of air flowing through the inside by adjusting the opening degree.

[0052] Further, the air supply device 40 according to this embodiment may be provided with a temperature adjustment unit 43 that adjusts the temperature of the air discharged from the heat exchanger 22 and guided to the high-pressure compressor 23. The temperature adjustment unit 43 may be, for example, a heat exchanger that performs heat exchange between the air guided to the high-pressure compressor 23 and a heat medium, or may be a nozzle that sprays temperature-adjusting water or steam onto the air guided to the high-pressure compressor 23.

[0053] According to this embodiment, the following operational effects are achieved. In this embodiment, a supply side bypass pipe 41 is provided that guides the air compressed by the low-pressure compressor 21 to the high-pressure compressor 23 so as to bypass the heat exchanger 22. Thereby, by mixing the low-temperature supply gas that has passed through the heat exchanger 22 and the high-temperature air that has not passed through the heat exchanger 22, the temperature of the air guided to the high-pressure compressor 23 can be adjusted. Therefore, the temperature of the supply gas guided to the heat engine 10 can be adjusted.

[0054] Further, in this embodiment, a temperature adjustment unit 43 for adjusting the temperature of the air guided to the high-pressure compressor 23 is provided. Thereby, the temperature of the air guided to the high-pressure compressor 23 can be adjusted. Therefore, the temperature of the supply gas guided to the heat engine 10 can be adjusted. Further, by providing the temperature adjustment unit 43, even when there are fluctuations due to variations in balance at partial load or aging deterioration, it is possible to respond by adjusting the temperature.

[0055] Further, in the present embodiment, an exhaust-side bypass pipe 42 is provided to guide the air expanded by the high-pressure expander 24 to the low-pressure expander 25 so as to bypass the heat exchanger 22. Thereby, the amount of exhaust air guided to the heat exchanger 22 can be adjusted. Therefore, the amount of heat exchange in the heat exchanger 22 can be adjusted. Thus, the temperature of the air guided to the high-pressure compressor 23, which is the object of heat exchange, can be adjusted. Therefore, the temperature of the supply gas guided to the heat engine 10 can be adjusted.

[0056] Note that the present disclosure is not limited to the above-described embodiments, and can be appropriately modified without departing from the gist thereof. For example, in the above embodiment, an example in which an SOEC and an engine are applied as the heat engine 10 has been described, but the present disclosure is not limited thereto. The gas supply device 20 according to the present embodiment can be applied to any heat engine as long as it is a heat engine that uses a high-pressure compressor. In addition, it can be preferably applied to a heat engine having an operating pressure of 0.5 MPa or more. In particular, it can be more preferably applied to a heat engine having an operating pressure of 3 MPa or more.

[0057] Further, when an engine is applied as the heat engine 10, the output density per unit volume can be improved by increasing the operating pressure of the supercharged engine. Further, when an SOEC is applied as the heat engine 10, by operating at a high pressure, the efficiency can be improved or the generated hydrogen can be pressurized.

[0058] Further, according to the requirements of the heat engine 10, the rotation speeds of the low-pressure compressor 21 and the high-pressure compressor 23 may be controlled. Further, vanes or valves may be provided at the inlets and outlets of the low-pressure compressor 21 and the high-pressure compressor 23. The flow rate and pressure of the gas supplied in response to the requirements of the heat engine 10 may be adjusted by adjusting the rotation speed of each compressor or the opening degree of the vanes or valves.

[0059] The gas supply device and the method for starting the gas supply device described in the above-described embodiments can be understood as follows, for example. The gas supply device according to the first aspect of the present disclosure is a gas supply device (20) that supplies gas to a heat engine (10), and includes a first compressor (21) that compresses supply gas, which is the gas to be supplied to the heat engine (10); a heat exchanger (22) into which the supply gas compressed by the first compressor (21) is introduced; a second compressor (23) that compresses the supply gas that has undergone heat exchange in the heat exchanger (22); a first supply unit (33) that supplies the supply gas compressed by the second compressor (23) to the heat engine (10); and a first discharge unit (34, 35) that guides exhaust gas, which is the gas discharged from the heat engine (10), to the heat exchanger (22). The heat exchanger (22) cools the supply gas by performing heat exchange between the supply gas and the exhaust gas.

[0060] In the above configuration, the heat exchanger cools the supply gas by performing heat exchange between the supply gas and the exhaust gas. Thereby, the exhaust gas discharged from the first discharge unit can be used to cool the supply gas between the first compressor and the second compressor. Therefore, compared with the case of using a refrigerant for separately cooling the supply gas, the energy efficiency of the entire device can be improved.

[0061] The gas supply device according to the second aspect of the present disclosure includes, in the first aspect of the present disclosure, a heat recovery unit (24, 25) that recovers the heat of the exhaust gas discharged from the heat engine (10).

[0062] In the above configuration, a heat recovery unit that recovers the heat of the exhaust gas discharged from the heat engine is provided. Thereby, the heat of the exhaust gas can be recovered. Therefore, when the recovered heat is used in the device, the energy efficiency of the entire device can be improved.

[0063] The gas supply device according to the third aspect of the present disclosure includes, in the second aspect of the present disclosure, the heat recovery unit (24, 25) provided on the upstream side and / or the downstream side of the heat exchanger (22).

[0064] In the above configuration, the heat recovery unit is provided on the upstream side and / or the downstream side of the heat exchanger. Thereby, the heat of the exhaust gas can be recovered on the upstream side and / or the downstream side of the heat exchanger. Further, when the heat recovery unit is provided on the upstream side of the heat exchanger, the temperature of the exhaust gas can be adjusted by recovering the heat of the exhaust gas in the heat recovery unit. Therefore, since the temperature of the exhaust gas introduced into the heat exchanger can be set to an appropriate temperature, the supply gas, which is the heat exchange partner in the heat exchanger, can be suitably cooled.

[0065] The gas supply device according to the fourth aspect of the present disclosure is, in the third aspect of the present disclosure, wherein the heat recovery units (24, 25) are provided on the downstream side of the heat exchanger (22), and the heat exchanger (22) heats the exhaust gas by performing heat exchange between the supply gas and the exhaust gas.

[0066] In the above configuration, the heat recovery unit is provided on the downstream side of the heat exchanger, and the heat exchanger heats the exhaust gas. Thereby, the exhaust gas heated by the heat exchanger is supplied to the heat recovery unit. Therefore, the occurrence of condensation and freezing in the heat recovery unit can be suppressed, so that the amount of recovered heat in the heat recovery unit can be increased.

[0067] The gas supply device according to the fifth aspect of the present disclosure is, in any one of the second to fourth aspects of the present disclosure, wherein the heat recovery units (24, 25) have expanders (24, 25) that expand the supplied exhaust gas, and the expanders (24, 25) are connected to the first compressor (21) and / or the second compressor (23), and drive the first compressor (21) and / or the second compressor (23) connected by the force of expanding the exhaust gas.

[0068] In the above configuration, the expander is connected to the first compressor and / or the second compressor, and drives the connected first compressor and / or second compressor by the force of expanding the exhaust gas. Thereby, the first compressor and / or the second compressor can be driven by utilizing the heat of the exhaust gas. Therefore, the energy efficiency of the entire apparatus can be improved.

[0069] In the gas supply device according to the sixth aspect of the present disclosure, in any one of the second aspect to the fifth aspect of the present disclosure, the temperature of the exhaust gas discharged from the heat engine (10) is set to a temperature equal to or lower than the dew point temperature of the exhaust gas when heat is recovered by the heat recovery unit (24, 25).

[0070] In the above configuration, the temperature of the exhaust gas discharged from the heat engine is set to a temperature equal to or lower than the dew point temperature of the exhaust gas when heat is recovered by the heat recovery unit. Thereby, the gas supply device can be applied to a heat engine that discharges exhaust gas at such a temperature.

[0071] In the gas supply device according to the seventh aspect of the present disclosure, in any one of the first aspect to the sixth aspect of the present disclosure, the heat engine (10) has a solid oxide electrolysis cell.

[0072] In the above configuration, the heat engine has a solid oxide electrolysis cell (SOEC). Thereby, the gas supply device can be applied to the SOEC.

[0073] The gas supply device according to the eighth aspect of the present disclosure, in any one of the first to seventh aspects of the present disclosure, includes a second supply unit (31) that supplies the supply gas to the heat exchanger (22), a second discharge unit (36) through which the exhaust gas heated by heat exchange in the heat exchanger (22) is discharged, a first expander (25) that is connected to the second discharge unit (36) and recovers the heat of the exhaust gas discharged from the heat exchanger (22) and expands the exhaust gas, a first connection unit (39) that connects the second supply unit (31) and the second discharge unit (36), and a first flow rate adjustment unit (39a) that adjusts the flow rate of the gas flowing in the first connection unit (39). The first expander (25) is connected to the first compressor (21) and drives the first compressor (21) by the force of expanding the gas.

[0074] In the above configuration, a first connection unit that connects the second supply unit and the second discharge unit is provided. Thereby, for example, when starting the gas supply device and supplying gas to the first compressor, the gas discharged from the first compressor is guided to the second discharge unit through the second supply unit and the first connection unit. The second discharge unit is connected to the first expander. Therefore, when starting the gas supply device, gas can be supplied to the first expander. The first expander drives the first compressor by expanding the gas. Therefore, when starting the gas supply device, the first compressor can be driven using the driving force of the first expander. Therefore, even when a drive source for driving the first compressor is provided separately from the first expander, the required driving force of the drive source can be reduced. Therefore, the drive source can be miniaturized. Therefore, the entire gas supply device can be miniaturized and the initial cost can be reduced.

[0075] The gas supply device according to the ninth aspect of the present disclosure is, in any one of the first to eighth aspects of the present disclosure, connected to the first discharge portions (34, 35), and recovers heat of the exhaust gas discharged from the heat engine (10) and expands the exhaust gas. It includes a second expander (24), a second connection portion (38) that connects the first supply portion (33) and the first discharge portions (34, 35), and a second flow rate adjustment portion (38a) that adjusts the flow rate of the gas flowing through the second connection portion (38). The second expander (24) is connected to the second compressor (23), and drives the second compressor (23) connected by the force of expanding the exhaust gas.

[0076] In the above configuration, a second connection portion that connects the first supply portion and the first discharge portion is provided. Thereby, for example, when starting the gas supply device, when gas is supplied to the second compressor, the gas discharged from the second compressor is guided to the first discharge portion via the first supply portion and the second connection portion. The first discharge portion is connected to the second expander. Therefore, when starting the gas supply device, gas can be supplied to the second expander. The second expander drives the second compressor by expanding the gas. Therefore, when starting the gas supply device, the second compressor can be driven using the driving force of the second expander. Therefore, even when a drive source for driving the second compressor is provided separately from the second expander, the required driving force of the drive source can be reduced. Therefore, the drive source can be miniaturized. Therefore, the entire gas supply device can be miniaturized and the initial cost can be reduced.

[0077] The gas supply device according to the tenth aspect of the present disclosure is, in any one of the first to ninth aspects of the present disclosure, provided with a supply side bypass portion that guides the supply gas compressed by the first compressor to the second compressor so as to bypass the heat exchanger.

[0078] In the above configuration, a supply-side bypass section is provided that guides the supply gas compressed by the first compressor to the second compressor so as to bypass the heat exchanger. As a result, by mixing the low-temperature supply gas that has passed through the heat exchanger and the high-temperature supply gas that has not passed through the heat exchanger, the temperature of the supply gas guided to the second compressor can be adjusted. Therefore, the temperature of the supply gas guided to the heat engine can be adjusted.

[0079] The gas supply device according to the 11th aspect of the present disclosure is any one of the 1st to 10th aspects of the present disclosure, and includes a second supply section (31) that supplies the supply gas to the heat exchanger (22), a second discharge section (36) from which the discharged gas heated by performing heat exchange in the heat exchanger (22) is discharged, a first expander (25) that is connected to the second discharge section (36) and recovers the heat of the discharged gas discharged from the heat exchanger (22) and expands the discharged gas, a second expander (24) that is connected to the first discharge sections (34, 35) and recovers the heat of the discharged gas discharged from the heat engine (10) and expands the discharged gas, and a discharge-side bypass section (42) that guides the discharged gas discharged from the second expander (24) to the first expander (25) so as to bypass the heat exchanger.

[0080] In the above configuration, a discharge-side bypass section is provided that guides the discharged gas discharged from the second expander to the first expander so as to bypass the heat exchanger. As a result, the amount of discharge air guided to the heat exchanger can be adjusted. Therefore, the amount of heat exchange in the heat exchanger can be adjusted. Thus, the temperature of the air guided to the second compressor, which is the object of heat exchange, can be adjusted. Therefore, the temperature of the supply gas guided to the heat engine can be adjusted.

[0081] A method for starting a gas supply device according to a first aspect of the present disclosure is a method for starting a gas supply device (20) that supplies gas to a heat engine (10). The gas supply device (20) includes a first compressor (21) that compresses supply gas, which is the gas supplied to the heat engine (10); a heat exchanger (22) into which the supply gas compressed by the first compressor (21) is introduced; a second compressor (23) that compresses the supply gas that has undergone heat exchange in the heat exchanger (22); a first supply unit (33) that supplies the supply gas compressed by the second compressor (23) to the heat engine (10); a first discharge unit (34, 35) that guides exhaust gas, which is the gas discharged from the heat engine, to the heat exchanger; a second supply unit (31) that supplies the supply gas to the heat exchanger (22); a second discharge unit (36) from which the exhaust gas heated by heat exchange in the heat exchanger (22) is discharged; a first expander (25) that is connected to the second discharge unit (36) and recovers the heat of the exhaust gas discharged from the heat exchanger (22) and expands the exhaust gas; a first connection part (39) that connects the second supply unit (31) and the second discharge unit (36); and a flow rate adjustment valve (39a) that adjusts the flow rate of the gas flowing in the first connection part (39). The heat exchanger (22) cools the supply gas by performing heat exchange between the supply gas and the exhaust gas, and includes a compressor starting step of starting the first compressor (21) and a flow rate adjustment valve opening step of changing the flow rate adjustment valve (39a) from a closed state to an open state.

[0082] The above configuration includes a flow control valve opening process of changing the flow control valve from a closed state to an open state when the gas supply device is started. By opening the flow control valve, gas can be supplied to the first expander when the gas supply device is started. The first expander drives the first compressor by expanding the gas. Therefore, when the gas supply device is started, the first compressor can be driven using the driving force of the first expander. Thus, even when a drive source for driving the first compressor is provided separately from the first expander, the required driving force of the drive source can be reduced. Thus, the drive source can be miniaturized. Thus, the entire gas supply device can be miniaturized and the initial cost can be reduced.

Explanation of Signs

[0083] 10: Heat engine 20: Gas supply device 21: Low-pressure compressor (first compressor) 22: Heat exchanger 23: High-pressure compressor (second compressor) 24: High-pressure expander (heat recovery section) 25: Low-pressure expander (heat recovery section) 27: Electric motor 28: Electric motor 30: Air supply pipe 30a: Air supply valve 31: First low-pressure air supply pipe (second supply section) 31a: First low-pressure air supply valve 32: Second low-pressure air supply pipe 32a: Second low-pressure air supply valve 33: High-pressure air supply pipe (first supply section) 33a: High-pressure air supply valve 34: High-pressure air discharge pipe (first discharge section) 34a: High-pressure air discharge valve 35: First low-pressure air discharge pipe (first discharge section) 36: Second low-pressure air discharge pipe (second discharge section) 36a: Second low-pressure air discharge valve 37: Air discharge pipe 38: High-pressure connection pipe (second connection part) 38a: High-pressure connection valve (second flow rate adjustment part) 39: Low-pressure connection pipe (first connection part) 39a: Low-pressure connection valve (first flow rate adjustment part, flow rate adjustment valve) 40: Air supply device 41: Supply-side bypass pipe (supply-side bypass part) 41a: Supply-side bypass valve 42: Discharge-side bypass pipe (discharge-side bypass part) 42a: Discharge-side bypass valve 43: Temperature adjustment part

Claims

1. A gas supply device for supplying gas to a heat engine, comprising: a first compressor for compressing supply gas which is the gas to be supplied to the heat engine; a heat exchanger into which the supply gas compressed by the first compressor is introduced; a second compressor for compressing the supply gas that has undergone heat exchange in the heat exchanger; a first supply section for supplying the supply gas compressed by the second compressor to the heat engine; a first discharge section for guiding exhaust gas, which is the gas discharged from the heat engine, to the heat exchanger; and the heat exchanger cools the supply gas by performing heat exchange between the supply gas and the exhaust gas. The gas supply device.

2. The gas supply device according to claim 1, further comprising a heat recovery section for recovering heat from the exhaust gas discharged from the heat engine.

3. The gas supply device according to claim 2, wherein the heat recovery section is provided on the upstream side and / or the downstream side of the heat exchanger.

4. The heat recovery section is provided on the downstream side of the heat exchanger, and the heat exchanger heats the exhaust gas by performing heat exchange between the supply gas and the exhaust gas. The gas supply device according to claim 3.

5. The heat recovery section has an expander for expanding the supplied exhaust gas, the expander is connected to the first compressor and / or the second compressor, and drives the connected first compressor and / or the second compressor by the force of expanding the exhaust gas. The gas supply device according to claim 2.

6. The temperature of the exhaust gas discharged from the heat engine is a temperature that becomes equal to or lower than the dew point temperature of the exhaust gas when heat is recovered by the heat recovery section. The gas supply device according to claim 2.

7. The heat engine has a solid oxide type electrolytic cell. The gas supply device according to claim 1.

8. a second supply section for supplying the supply gas to the heat exchanger; a second discharge section through which the exhaust gas heated by performing heat exchange in the heat exchanger is discharged; a first expander connected to the second discharge section, recovering heat from the exhaust gas discharged from the heat exchanger and expanding the exhaust gas; a first connection section connecting the second supply section and the second discharge section; a first flow rate adjustment section for adjusting the flow rate of the gas flowing through the first connection section; and the first expander is connected to the first compressor and drives the first compressor by the force of expanding the gas. The gas supply device according to claim 1.

9. A second expander that is connected to the first discharge section, recovers heat of the exhaust gas discharged from the heat engine, and expands the exhaust gas. A second connection section that connects the first supply section and the first discharge section. A second flow rate adjustment section that adjusts a flow rate of gas flowing through the second connection section. The gas supply device according to claim 1, wherein the second expander is connected to the second compressor, and drives the second compressor connected by a force of expanding the exhaust gas.

10. The gas supply device according to claim 1, further comprising a supply-side bypass section that guides the supply gas compressed by the first compressor to the second compressor so as to bypass the heat exchanger.

11. A second supply section that supplies the supply gas to the heat exchanger. A second discharge section from which the exhaust gas heated by performing heat exchange in the heat exchanger is discharged. A first expander that is connected to the second discharge section, recovers heat of the exhaust gas discharged from the heat exchanger, and expands the exhaust gas. A second expander that is connected to the first discharge section, recovers heat of the exhaust gas discharged from the heat engine, and expands the exhaust gas. The gas supply device according to claim 1, further comprising a discharge-side bypass section that guides the exhaust gas discharged from the second expander to the first expander so as to bypass the heat exchanger.

12. A method for starting a gas supply device that supplies gas to a heat engine, the gas supply device comprising: a first compressor that compresses supply gas that is gas supplied to the heat engine; a heat exchanger into which the supply gas compressed by the first compressor is introduced; a second compressor that compresses the supply gas that has undergone heat exchange in the heat exchanger; a first supply section that supplies the supply gas compressed by the second compressor to the heat engine; a first discharge section that guides exhaust gas, which is gas discharged from the heat engine, to the heat exchanger; a second supply section that supplies the supply gas to the heat exchanger; a second discharge section from which the exhaust gas heated by performing heat exchange in the heat exchanger is discharged; a first expander that is connected to the second discharge section, recovers heat of the exhaust gas discharged from the heat exchanger, and expands the exhaust gas; a first connection section that connects the second supply section and the second discharge section; a flow rate adjustment valve that adjusts a flow rate of gas flowing through the first connection section. ​ The heat exchanger cools the supply gas by performing heat exchange between the supply gas and the exhaust gas, a compressor starting step of starting the first compressor, and a flow rate control valve opening step of changing the flow rate control valve from a closed state to an open state. A starting method for a gas supply device including these steps.

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