Hydrogen co-firing unit for gas engines and gas engine using the same

Abstract

This invention provides a hydrogen co-firing unit for gas engines that allows for the easy addition of a hydrogen mixing function to existing natural gas-fired gas engines without significant modifications. [Solution] A hydrogen co-firing unit for a gas engine, provided on a hydrogen supply line added to the fuel supply line of a gas engine, for adjusting the flow rate of hydrogen gas, is characterized by comprising: a hydrogen gas pipe having a hydrogen gas inlet and outlet; a shut-off unit provided in the hydrogen gas pipe for shutting off the hydrogen gas in an emergency; and a housing portion in which the hydrogen gas pipe and the shut-off unit are housed, and the inlet and outlet are provided on the outer surface.

Description

Technical Field

[0001] The present invention relates to the configuration of a gas engine that operates on gaseous fuel, and particularly to a technology effective for retrofitting a natural gas dedicated gas engine to a hydrogen gas / natural gas dual-fuel engine.

Background Art

[0002] A gas engine that generates power by burning gaseous fuel such as natural gas or town gas inside the engine has a higher efficiency because the combustion temperature is high compared to a gas turbine. As part of a cogeneration system, various types of gas engines are adopted according to a wide range of applications, from domestic use such as buildings and factories to industrial use.

[0003] Conventionally, a general gas engine mainly uses natural gas distributed as a general commodity as fuel. Carbon dioxide (CO2) generated during the combustion of natural gas is considered one of the factors contributing to global warming, and there is a global movement to regulate its emissions. Since the combustion of hydrogen does not involve the generation of CO2, by replacing a part of the hydrocarbon component in the fuel with hydrogen, the amount of CO2 generated during power generation can be reduced.

[0004] As background art in this technical field, for example, there is a technology such as Patent Document 1. Patent Document 1 discloses "a premixed forced ignition type gas engine that ignites a premixed gas formed by mixing fuel gas and air with an ignition means, having a plurality of types of fuel gases with different flammable ranges, and supplying the plurality of types of fuel gases to an intake pipe at a mixing ratio according to operating conditions."

[0005] In the gas engine of Patent Document 1, it is stated that the flammable range can be changed according to operating conditions, the engine can be operated with a fuel gas suitable for the operating conditions, and good combustion can be obtained over a wide range. (Paragraph of Patent Document 1

[0006] etc.)

Prior Art Documents

Patent Documents

[0006] [Patent Document 1] Japanese Patent Publication No. 2004-190640 [Overview of the project] [Problems that the invention aims to solve]

[0007] As mentioned above, hydrogen is being positioned as a new resource for achieving carbon neutrality. Expansion of hydrogen use is expected on the demand side, including in the power generation, transportation, industrial, and residential sectors. For example, in the power generation sector, the goal is to introduce and popularize 30% hydrogen co-firing or hydrogen-only combustion in gas-fired power plants. However, currently, many gas engine operators own engines that are exclusively natural gas-fired.

[0008] Therefore, although there is a need among operators to convert existing natural gas-fired models into hydrogen-co-firing gas engines by adding hydrogen gas supply lines, the introduction of hydrogen gas / natural gas co-firing engines is difficult because it requires significant modifications to the gas engine itself.

[0009] The above-mentioned Patent Document 1 is a technology that initially envisioned a gas engine that supplies multiple types of fuel gases to the intake manifold in a mixture ratio according to the operating conditions of the gas engine, and does not take into account the challenges that arise when converting from a natural gas-fired gas engine to a hydrogen gas / natural gas mixed-fired engine as described above.

[0010] Therefore, the object of the present invention is to provide a hydrogen co-firing unit for a gas engine and a gas engine using the same, which can be easily added to an existing natural gas-fired gas engine without significant modifications to the existing gas engine. [Means for solving the problem]

[0011] To solve the above problems, the present invention provides a hydrogen co-firing unit for a gas engine, which is installed on a hydrogen supply line added to the fuel supply line of a gas engine and adjusts the flow rate of hydrogen gas, and is characterized by comprising: a hydrogen gas pipe having a hydrogen gas inlet and outlet; a shut-off unit provided in the hydrogen gas pipe for shutting off the hydrogen gas in an emergency; and a housing unit that houses the hydrogen gas pipe and the shut-off unit inside, with the inlet and outlet provided on its outer surface.

[0012] Furthermore, the gas engine of the present invention is characterized by using the above-mentioned hydrogen co-firing unit for gas engines. [Effects of the Invention]

[0013] According to the present invention, it is possible to realize a hydrogen co-firing unit for a gas engine and a gas engine using the same, which can be easily added to an existing natural gas-fired gas engine without significant modifications to the existing gas engine.

[0014] This makes it easier to convert natural gas-fired engines to hydrogen gas / natural gas mixed-fired engines, contributing to a reduction in carbon dioxide (CO2) emissions.

[0015] Other issues, configurations, and effects not mentioned above will be clarified by the following description of the embodiments. [Brief explanation of the drawing]

[0016] [Figure 1] This is a schematic diagram showing the general configuration of a gas engine according to one embodiment of the present invention. [Figure 2] This figure shows the schematic configuration of the hydrogen co-firing unit 10 shown in Figure 1. [Modes for carrying out the invention]

[0017] Embodiments of the present invention will be described below with reference to the drawings. In each drawing, identical components are denoted by the same reference numerals, and detailed descriptions of overlapping parts are omitted. [Examples]

[0018] Referring to FIGS. 1 and 2, a hydrogen co-firing unit for a gas engine according to an embodiment of the present invention and a gas engine using the same will be described. FIG. 1 is a system diagram showing a schematic configuration of the gas engine of this embodiment. FIG. 2 is a diagram showing a schematic configuration of the hydrogen co-firing unit 10 in FIG. 1. The present invention relates to a hydrogen co-firing unit for a gas engine in which devices such as a hydrogen gas pipe and a shut-off valve are housed in a casing and packaged.

[0019] As shown in FIG. 1, a gas engine 1 using the hydrogen co-firing unit for a gas engine of the present invention includes, as a fuel supply line, a second fuel gas supply pipe 102 for introducing natural gas from an external natural gas supply facility (not shown) and a second gas flow rate adjustment valve 92 for adjusting the supply amount of natural gas to the gas engine 1. The second fuel gas supply pipe 102 and the second gas flow rate adjustment valve 92 are fuel supply lines that are initially installed in an existing natural gas dedicated combustion gas engine.

[0020] Further, the gas engine 1 includes a first fuel gas supply pipe 101 for introducing hydrogen gas from an external hydrogen gas supply facility (not shown), a hydrogen co-firing unit 10 for adjusting the supply amount of hydrogen gas to the gas engine 1, and a first gas flow rate adjustment valve 91. The first fuel gas supply pipe 101, the hydrogen co-firing unit 10, and the first gas flow rate adjustment valve 91 are fuel supply lines additionally installed when converting from a natural gas dedicated combustion gas engine to a hydrogen gas / natural gas co-firing engine.

[0021] The natural gas supplied through the second gas flow rate adjustment valve 92 and the hydrogen gas supplied through the first fuel gas supply pipe 101, the hydrogen co-firing unit 10, and the first gas flow rate adjustment valve 91 merge at the connection part (confluence part) of the second fuel gas supply pipe 102 and the first fuel gas supply pipe 101 and are sent to the mixture supply pipe 110 as a mixture of natural gas and hydrogen gas.

[0022] The mixture of natural gas and hydrogen gas is further mixed with the air supplied through the air filter 60 in the gas mixer 31, and is sent as a mixture of natural gas, hydrogen gas, and air to the turbocharger 70. The mixture of natural gas, hydrogen gas, and air that has passed through the turbocharger 70 is sent to the first intercooler 81 and the second intercooler 82 through the first intake pipe 111.

[0023] The mixture of natural gas, hydrogen gas, and air that has passed through the first intercooler 81 and the second intercooler 82 is supplied as gaseous fuel to the engine 30 through the second intake pipe 112, the throttle valve 32, and the third intake pipe 113.

[0024] Also, a part of the mixture of natural gas and hydrogen gas that has merged at the connection part (confluence part) of the second fuel gas supply pipe 102 and the first fuel gas supply pipe 101 is sent to the second intake pipe 112 through the turbo bypass valve 33, and is mixed with the mixture of natural gas, hydrogen gas, and air that has passed through the first intercooler 81 and the second intercooler 82, and is supplied as gaseous fuel to the engine 30 through the throttle valve 32 and the third intake pipe 113.

[0025] The engine 30 generates power by burning the mixture of natural gas, hydrogen gas, and air as gaseous fuel inside the engine, and generates electricity by the generator 40. Part or all of the exhaust gas of the engine 30 is sent to the turbocharger 70 through the exhaust pipe 114, and is reused as energy for driving the compressor connected coaxially with the turbine of the turbocharger 70.

[0026] The gas engine 1 further includes a gas engine controller 50 that controls the entire gas engine 1, and a hydrogen co - firing unit control panel 20 that is additionally installed together with the first fuel gas supply pipe 101, the hydrogen co - firing unit 10, and the first gas flow rate adjustment valve 91 when converting from a natural gas - only - burning gas engine to a hydrogen gas / natural gas co - firing engine.

[0027] The gas engine controller 50 controls the hydrogen co-firing unit control panel 20, the first gas flow control valve 91, the second gas flow control valve 92, the turbo bypass valve 33, the throttle valve 32, the engine 30, and the generator 40. The hydrogen co-firing unit control panel 20 controls the hydrogen co-firing unit 10 in response to commands from the gas engine controller 50, which is a higher-level control device.

[0028] The specific configuration of the hydrogen co-firing unit 10 will be explained using Figure 2.

[0029] As shown in Figure 2, the hydrogen co-firing unit 10 mainly comprises a hydrogen gas inlet 2, a hydrogen gas outlet 3, hydrogen gas piping 4, a shut-off valve 5, a gas filter 6, a regulator 7, a solenoid valve 8, and a flame arrestor 9. The hydrogen co-firing unit 10 also includes a ventilation fan 12 and a hydrogen detector 13. These components are housed within the housing 11 or installed on the outer surface of the housing 11, thereby forming a packaged hydrogen co-firing unit 10.

[0030] The hydrogen co-firing unit 10 is installed on a hydrogen supply line added to the fuel supply line of the gas engine 1 and adjusts the flow rate of hydrogen gas. The hydrogen gas piping 4 has a hydrogen gas inlet 2 and a hydrogen gas outlet 3. A shut-off valve 5 is installed in the hydrogen gas piping 4 and shuts off the hydrogen gas in an emergency. The hydrogen gas piping 4 and the shut-off valve 5 are housed inside the housing 11, and the hydrogen gas inlet 2 and hydrogen gas outlet 3 are located on the outer surface of the housing 11.

[0031] By housing and packaging equipment such as hydrogen gas piping 4 and shut-off valves 5 within the enclosure 11, the function of mixing hydrogen can be easily added to existing natural gas-fired gas engines without significant modifications to the existing gas engines, making it possible to convert natural gas-fired gas engines into hydrogen gas / natural gas mixed-fired engines.

[0032] The hydrogen detector 13 detects whether or not there is a hydrogen gas leak inside the housing 11. If the hydrogen detector 13 detects a hydrogen gas leak inside the housing 11, it sounds an alarm and sends a signal to the shut-off valve 5 to shut off the hydrogen gas.

[0033] The ventilation fan 12 ventilates the inside of the enclosure 11. The ventilation fan 12 constantly ventilates the inside of the enclosure 11, so that even if hydrogen gas leaks into the enclosure 11, the concentration inside the enclosure 11 will not reach the lower explosive limit. The ventilation rate by the ventilation fan 12 is kept constant. By providing the ventilation fan 12, the hydrogen co-firing unit 10 can be made non-explosion-proof, eliminating the need to make the enclosure 11 robust, thus contributing to the compactness of the hydrogen co-firing unit 10. Furthermore, the non-explosion-proof design allows for the use of general equipment, which also reduces costs.

[0034] The solenoid valve 8, like the shut-off valve 5, shuts off the hydrogen gas. The flame arrester 9 is installed between the solenoid valve 8 and the hydrogen gas outlet 3. The solenoid valve 8 and the flame arrester 9 prevent damage to the entire hydrogen gas piping in the event of a flashback.

[0035] The gas filter 6 has the function of removing foreign matter contained in the hydrogen gas. The regulator 7 has the function of adjusting the pressure of the hydrogen gas. As described above, the flame arrester 9 has the function of preventing flashback from the hydrogen gas outlet 3 side from flowing into the hydrogen gas piping 4.

[0036] As shown in Figure 2, in the hydrogen co-firing unit 10 of the present invention, a shut-off valve 5, a gas filter 6, a regulator 7, a solenoid valve 8, and a flame arrestor 9 are arranged in order from the hydrogen gas inlet 2 to the hydrogen gas outlet 3. In other words, the equipment is arranged sequentially on a single hydrogen gas piping system 4 and housed within the housing 11. The housing 11 is also provided with double doors (not shown). Opening these doors allows for a clear view of the equipment installed on the hydrogen gas piping system 4, facilitating maintenance.

[0037] Furthermore, as shown in Figures 1 and 2, the gas engine 1 of this embodiment is equipped with a first gas flow rate control valve 91, which is located between the junction of the hydrogen supply line with the fuel supply line and the hydrogen gas outlet 3, and adjusts the flow rate of hydrogen gas according to the hydrogen co-firing ratio setting of the gas engine 1. In Figures 1 and 2, the first gas flow rate control valve 91 is installed separately from the hydrogen co-firing unit 10, but the first gas flow rate control valve 91 may also be installed inside the hydrogen co-firing unit 10.

[0038] The gas engine controller (control panel) 50 installed in the existing natural gas-fired gas engine will be modified to allow input of the hydrogen co-firing ratio to natural gas. By inputting the hydrogen co-firing ratio into the gas engine controller (control panel) 50, signals specifying the opening amount will be sent to the first gas flow control valve 91 and the second gas flow control valve 92 to achieve the desired hydrogen co-firing ratio. This configuration is effective when there are constraints on the distance from the engine 30 connection port to the gas flow control valves (first gas flow control valve 91, second gas flow control valve 92), and enables coordination with the hydrogen co-firing ratio control of the gas engine 1.

[0039] As described above, according to the present invention, by housing and packaging equipment such as hydrogen gas piping 4 and shut-off valve 5 within the housing 11, a function to mix hydrogen can be easily added to an existing natural gas-fired gas engine without making significant changes to the existing gas engine, making it possible to convert a natural gas-fired gas engine into a hydrogen gas / natural gas mixed-fired engine.

[0040] The present invention provides a function to add hydrogen to a fuel gas, primarily methane, at an arbitrary mixing ratio without significantly modifying the engine itself. The mixing ratio of the fuel gas, controlled by adjusting the opening of gas flow control valves for natural gas and hydrogen gas, is mixed with combustion air in a gas mixer 31 and supplied as a mixture to the combustion chamber of the engine 30.

[0041] The mixture flow rate is controlled by a combination of a throttle valve 32 and a turbo bypass valve 33. The hydrogen gas supply unit integrates ventilation, hydrogen detection, and shutoff functions into a closed enclosure 11, and the inside of the enclosure 11 is constantly ventilated. Therefore, in the event of a hydrogen leak, hydrogen detection shuts off the hydrogen supply and dilution inside the enclosure occurs in conjunction, resulting in high safety.

[0042] It should be noted that the present invention is not limited to the embodiments described above, and various modifications are included. For example, the embodiments described above are described in detail to make the present invention easier to understand, and are not necessarily limited to those having all the configurations described. Furthermore, it is possible to replace parts of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add configurations from other embodiments to the configuration of one embodiment. In addition, it is possible to add, delete, or replace parts of the configuration of each embodiment with other configurations. [Explanation of symbols]

[0043] 1…Gas engine 2…Hydrogen gas inlet 3…Hydrogen gas outlet 4…Hydrogen gas piping 5…Shut-off valve 6…Gas filter 7…Regulator 8… Solenoid valve 9... Frame Arrester 10…Hydrogen co-firing unit 11…Cabinet 12…Ventilation fan 13…Hydrogen detector 20…Hydrogen co-firing unit control panel 30… Engine 31... Gas mixer 32... Throttle valve 33... Turbo bypass valve 40…Generator 50…Gas engine controller 60... Air filter 70... Turbocharger 81...First intercooler 82...Second intercooler 91...First gas flow control valve (hydrogen) 92... Second gas flow control valve (natural gas) 101...First fuel gas supply pipe (hydrogen) 102... Second fuel gas supply pipe (natural gas) 110... Mixture supply pipe 111...First intake manifold 112...Second intake manifold 113...Third intake manifold 114... Exhaust pipe.

Claims

1. A hydrogen co-firing unit for a gas engine, installed on a hydrogen supply line added to the fuel supply line of a gas engine, which adjusts the flow rate of hydrogen gas, A hydrogen gas pipeline having a hydrogen gas inlet and outlet, A shut-off section is provided in the hydrogen gas piping to shut off the hydrogen gas in an emergency, The hydrogen gas piping and the shut-off section are housed inside the housing, and the inlet and outlet are provided on the outer surface of the housing, A hydrogen co-firing unit for a gas engine, characterized by comprising the following features.

2. A hydrogen co-firing unit for a gas engine according to claim 1, A hydrogen co-firing unit for a gas engine, characterized by comprising a hydrogen co-firing unit control panel for controlling the operation of the aforementioned hydrogen co-firing unit for a gas engine.

3. A hydrogen co-firing unit for a gas engine according to claim 1, A hydrogen co-firing unit for a gas engine, characterized by comprising a hydrogen detection unit for detecting hydrogen gas within the housing.

4. A hydrogen co-firing unit for a gas engine according to claim 1, A hydrogen co-firing unit for a gas engine, characterized by comprising a ventilation section for ventilating the inside of the housing.

5. A hydrogen co-firing unit for a gas engine according to claim 1, A solenoid valve that shuts off hydrogen gas, A flame arrestor is provided between the solenoid valve and the discharge port, A hydrogen co-firing unit for a gas engine, characterized by comprising the following features.

6. A hydrogen co-firing unit for a gas engine according to claim 1, From the inlet toward the outlet, in order: The aforementioned blocking section, A gas filter that removes foreign matter contained in hydrogen gas, A regulator that adjusts the pressure of hydrogen gas, A solenoid valve that shuts off hydrogen gas, A flame arrestor that prevents flashback from the outlet side from flowing into the hydrogen gas piping, A hydrogen co-firing unit for a gas engine, characterized by comprising the following features.

7. A gas engine characterized by using a hydrogen co-firing unit for a gas engine as described in any one of claims 1 to 6.

8. A gas engine according to claim 7, A gas engine characterized by comprising a gas flow control valve provided between the junction of the hydrogen supply line with the fuel supply line and the discharge port, which adjusts the flow rate of hydrogen gas according to the hydrogen co-firing ratio set value of the gas engine.

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