JPH0466757A - Methanol reforming type gas engine-cogeneration device and method - Google Patents

Abstract

PURPOSE:To increase the overall energy utilization efficiency by using methanol as a substitute energy source for the primary energy, reforming the methanol by utilizing the waste heat of a gas engine, and burning the energized reformed gas to drive a gas engine generator. CONSTITUTION:While the jacket cooling water of a gas engine device A to drive a generator 27 by using a methanol reforming gas as a fuel is let flow through a methanol vapor generator B and a warm water generator C to heat the generators, the exhaust gas of the gas engine device A is delivered to a methanol reforming device D to heat the device D. At the downstream side of the methanol reforming device D, a waste heat collecting boiler device E is provided, and a specific amount of steam from the waste heat collecting boiler device E is added to the methanol vapor fed to the methanol reforming device D by a steam adding amount control device F. And, a specific amount of air for combustion is mixed to the reformed gas from the methanol reforming device D by a fuel gas feeding control device G, and a mixture gas of the gas and the air is to be fed to a gas engine device A.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to the improvement of a gas engine cogeneration system that uses methanol as fuel. The resulting reformed gas is combusted to drive a gas engine power generator to obtain electrical energy.

This invention relates to a methanol reforming gas engine cogeneration system that makes it possible to significantly improve power generation efficiency and overall energy utilization efficiency by obtaining hot water energy and steam energy by utilizing waste heat.

(Prior Art) In recent years, so-called gas engine cogeneration systems have been widely used in buildings, hotels, etc. in urban areas.

However, all conventional gas engine cogeneration systems use city gas as fuel, and gas engine cogeneration systems that use reformed methanol gas as an alternative fuel have not yet been developed.

In addition, in the conventional gas engine cogeneration system, the power generation efficiency was approximately 31% as shown in Figure 4.
In addition, the NOx concentration in the exhaust gas is relatively low at about 2
000PPm, and the problem is that the C○ concentration is relatively high at about 11000PP.

On the other hand, in the field of automobile gas engines, development of gas engines that use methanol as fuel has focused on the lean nature of methanol combustion exhaust gas.For example, methanol is reformed using exhaust heat from gas engines. A system has been developed in which the reformed gas heated through the reaction is used as fuel for gas engines.
8-7822, Special Publication No. 60-37292, etc.).

There are two types of reactions called methanol reforming reactions, A and B below, and they are usually used without making a strict distinction between the names.

(A) Methanol decomposition reaction (ideal reaction) CH30H-
+C○+2H2...(1) (ΔH2, = 21.7K
can/mon)CHIOH+ n)-1,
Q −+ (2+n) H,+ (1-n) C○+
n CO□ ... (2) where ○〈n〈1 (B) Steam reforming reaction of methanol (ideal reaction) CH,
CH+ m H20-+ 3 H2+ CO24(Il
l-1) H2C(ΔH2,”11.8Kcan/
no Q l= (3) where m≧1 By the way, all of the conventional gas engines for automobiles that use reformed methanol gas as fuel utilize reformed methanol gas produced by the decomposition reaction in item (A) above. It mainly relates to the control of operating conditions (reformed gas temperature, gas pressure, catalyst layer temperature, etc.) when the methanol decomposition reaction is carried out using the heat of engine exhaust gas.

That is, all of the above-mentioned conventional technologies use the exhaust heat of the gas engine to perform a "decomposition reaction" on methanol in a methanol reforming gas engine, which is mainly used in automobile engines, to produce heated reformed gas. The aim is to improve the thermal efficiency of a gas engine by using it as engine fuel.

However, when using a gas engine that uses methanol as fuel as an industrial power generation device or a power drive device, it is difficult to use the fuel (methanol) effectively by simply improving the thermal efficiency of the engine as in the conventional technology. This is insufficient. That is, it is necessary to use the exhaust heat of the gas engine not only for the methanol reforming reaction, but also for steam recovery and hot water recovery, and also to effectively utilize the cooling exhaust heat of the engine jacket.

Furthermore, in the methanol decomposition reaction of formulas (A) and (1) above, 1 mole of carbon monoxide (CO) and 2 moles of hydrogen gas (H2) are generated from 1 mole of methanol (CH30H). In the steam reforming reaction of formulas (A) and (3), 3 moles of hydrogen gas and 1 mole of carbon dioxide gas (CO2) are generated from 1 mole of methanol and 1 mole of steam (H2C).

Therefore, in a conventional gas engine that uses reformed gas produced by a methanol decomposition reaction as fuel, CO is generated as much as it contains a larger amount of CO than in the case where reformed gas produced by a steam reforming reaction is used as fuel. The problem is that the amount is large.

Furthermore, the operating conditions of the gas engine (e.g. excess air ratio,
As is clear from Figure 3, if the compression ratio, ignition timing, output, etc. are the same, the problem is that the NOx concentration in the exhaust gas will be higher than when using reformed gas from a steam reforming reaction. be.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned problems in conventional city gas type gas engine cogeneration systems and automobile gas engines that utilize methanol reformed residue, that is, in the former case, In addition to low power generation efficiency, NOx concentration and C
Also, the O concentration is high.

In the latter case, (a) simply improving the thermal efficiency of the engine is not enough to effectively utilize the fuel, and (b) since only the reformed gas from the so-called decomposition reaction is used, C○ in the exhaust gas is reduced. In addition to solving problems such as high concentrations of CO and NOx, based on this, we have improved not only the thermal efficiency of the gas engine but also the overall heat utilization rate, as well as reducing the CO and NOx concentrations in the exhaust gas. The purpose of the present invention is to provide a methanol reforming gas engine cogeneration system that makes it possible to reduce the amount of alcohol used.

That is, the present invention makes it possible to improve the thermal efficiency of a gas engine and reduce the amount of CO and NOx generated by using not only the reformed gas produced by the decomposition reaction but also the reformed gas produced by the steam reforming reaction of methanol. At the same time, the methanol reforming type makes it possible to significantly improve heat utilization efficiency by using engine exhaust heat to perform the methanol reforming reaction and steam recovery, and by using engine jacket cooling exhaust heat to recover hot water. The main object of the invention is to provide a gas engine cogeneration system.

(Means for Solving the Problems) The present invention provides a methanol reforming gas engine that reformes methanol using exhaust heat of a gas engine and burns the reformed gas to obtain output.

In a cogeneration system, a generator is connected to the gas engine output shaft, and the engine jacket cooling water exhaust heat and engine exhaust heat are effectively used to carry out the steam reforming reaction of methanol, as well as to recover hot water and steam. By using the reformed gas obtained by the steam reforming reaction as fuel for a gas engine, electrical energy, steam energy, and hot water energy can be efficiently obtained, and the amount of NOx and C○ generated in the exhaust gas can be reduced. This is a feature of the invention.

That is, the present device invention provides a gas engine device using reformed methanol gas as fuel; a generator driven by the gas engine device; a methanol steam generator heated by jacket cooling water of the gas engine device; and the jacket A hot water generator heated by cooling water; A methanol reformer heated by the exhaust gas of the gas engine device; An exhaust heat recovery boiler device provided on the downstream side of the methanol reformer; To the methanol reformer A steam addition amount control device that adds steam from an exhaust heat recovery boiler device to methanol vapor to be supplied; The basic structure of the invention is a fuel gas supply control device that supplies the mixed gas of the fuel gas to the gas engine device.

In addition, the present method invention uses methanol as fuel, reforms it into a hydrogen-rich gas fuel using a methanol reformer, supplies this reformed gas to a gas engine equipment to rotationally drive a generator, and In a methanol reforming gas engine cogeneration system that uses exhaust gas to reform the methanol and generate steam, methanol is evaporated using the exhaust heat of the cooling water from the engine jacket of the gas engine to maintain a constant pressure. In addition to obtaining methanol vapor, hot water is generated by recovering cooling water exhaust heat, and steam is further generated by recovering the exhaust heat of the engine exhaust gas, and a part of the steam is sent along with the methanol vapor to the upstream side of the exhaust heat recovery boiler device. The basic structure of the invention is to supply the reformed gas to the provided methanol reformer, generate reformed gas at a constant pressure, and supply it to the gas engine device.

(Function) The methanol steam generator is activated by the auxiliary heater,
The gas engine device is started by supplying the generated methanol vapor directly to the gas engine device.

When the gas engine device is started and the exhaust gas temperature and jacket cooling water temperature rise, the methanol steam generator is driven by the heat of the jacket cooling water, and the hot water generator is also driven to recover hot water.

Further, the catalyst layer of the methanol reformer is heated by the heat of the engine exhaust gas, and the exhaust heat recovery boiler device is operated to recover steam.

Methanol vapor from the methanol steam generator is mixed with a certain amount of steam according to the steam load on the steam load side by a steam addition amount control device, and the raw material gas, which is a mixture of steam and methanol vapor, is sent to the methanol reformer. sent to.

Decomposition or steam in methanol reformer? r! A predetermined amount of air is mixed with the reformed gas in a fuel gas supply amount control device, and fuel gas is supplied to the gas engine device at a flow rate according to the command signal.

(Example) Hereinafter, the present invention will be described in detail based on FIGS. 1 to 4.

FIG. 1 is an overall system diagram of a methanol reforming gas engine cogeneration system according to the present invention, in which A is a gas engine system, B is a methanol steam generator, C is a hot water generator, and D is a hot water generator. Methanol reformer, E
is an exhaust heat recovery boiler device, F is a steam addition amount control device, G is
is the fuel gas supply control device.

The gas engine equipment mA is mainly composed of a gas engine 26 equipped with a spark plug 25, a cooling jacket 26a, etc., and a generator 27 is connected to its output shaft 26b.

The methanol steam generating bag WB is a methanol steam generator 3 equipped with an electric heater 4 and a hot water heater 6a. It is composed of a control valve 5, a methanol vapor pressure inspection device 9, a methanol vapor pressure controller 10, etc., and controls the control valve 5 (i.e., cooling water W from the engine jacket cooling line 6) so that the generated vapor pressure of methanol reaches a set value. flow rate) is controlled.

The hot water generator C is formed of a hot water generator 8, a jacket cooling water pump 7, etc., and recovers the exhaust heat of the jacket cooling water W circulating through the control valve 5 to extract hot water WH.

The methanol reformer WD includes a methanol reformer 31 having a built-in catalyst layer for promoting methanol decomposition or steam storage, a raw material gas heating device 32 provided downstream of the methanol reformer 31, and a catalyst layer temperature detector, as described later. 30, a control damper 28, a temperature controller 29, a connecting duct 33, etc., and the catalyst layer and raw material gas (methanol vapor +
(water vapor) is heated.

That is, the temperature of the catalyst layer in the methanol reformer 31 is controlled to a predetermined temperature by controlling the controller damper 28 via the temperature controller 29 and adjusting the amount of exhaust gas inflow. H' is bypassed to the exhaust gas inlet side of the exhaust heat recovery boiler 35 via the bypass duct 34.

The exhaust heat recovery boiler device E is provided on the downstream side of the methanol reformer, and is connected to the exhaust heat recovery boiler 35, water supply line 35a, steam pressure detector 20, steam flow rate control valve 22, steam pressure controller 21, etc. It is formed.

The steam addition amount control device F is formed of a methanol steam flow rate detector 12, a ratio setting device 16, a steam flow rate detector 18, a steam flow rate control valve 19, a steam flow rate controller 17, etc., and as described later, is a methanol reformer. The amount of water vapor added to the methanol vapor supplied to the tank is controlled to a predetermined value. The methanol vapor flow rate is controlled by the methanol vapor control valve 1 via the controller 14 based on a signal from the reformed gas pressure detector 13.
5, the generated pressure of the reformed gas D' is adjusted to a constant value.

The fuel gas supply control device G supplies reformed gas D from a mixer 37 equipped with an air valve 23 and a methanol reformer.
'The mixing ratio of air Ar and reformed gas D' and the mixture of both (fuel gas G'
) is controlled.

In FIG. 1, 1 is a methanol tank, 2 is a methanol pump, 11 is a starting methanol control valve, and 36 is a chimney.

Next, the operation of the methanol reforming gas engine cogeneration system of the present invention will be explained.

Methanol is sent from a methanol tank 1 to a methanol vapor generator 3 by a methanol pump 2. At the time of starting, the engine jacket cooling water line 6 is cold and the methanol steam generator 3 does not generate methanol vapor, so it is heated by the starting electric heater 4.

Even if methanol vapor is generated by heating the heater 4,
At the time of startup, the reformer HD is still cold and no reforming reaction occurs, so the starting methanol control valve 11.
A mixture of methanol vapor and air is supplied directly to the gas engine 26 via the mixer 37 .

When the gas engine 26 is started, the exhaust gas after combustion in the engine 26 passes through the exhaust duct 33 and is discharged from the chimney 36. At this time, the reformer 31. The reformer is warmed up by exchanging heat with the fi gas positive heating device 32 and the exhaust heat recovery boiler 35, and steam S is soon generated from the exhaust heat recovery boiler device E.

On the other hand, the temperature of the gas engine jacket cooling water line 6 is also gradually raised, and the cooling water W (hot water with a rating of 90 to 95°C) exiting the engine jacket section 26a is transferred to the gas engine jacket cooling water line 6 via the control valve 5. part flows to the heater 6a of the methanol steam generator 3, and the remaining part flows to the heater 6a of the methanol steam generator 3.
It joins with the cooling water that has passed through it and enters the hot water generator 8, where it is cooled by heat exchange, and then circulated again to the engine jacket section by the jacket cooling water pump 7.

As a result, even if the starting electric heater 4 is turned off, the exhaust heat of the jacket cooling water W can eventually cover methanol vapor generation.

When it is confirmed by the catalyst bed temperature sensor 30 that the reformer has been warmed up sufficiently, the methanol vapor control valve 15 and the water vapor control valve 19 are opened, and a mixture of methanol vapor and water vapor F' is generated. 75-
It is sent to the methanol reformer 31 through the 4-heater 32.

In addition, in the reformer 31, the above-mentioned B.
As seen in the reaction of equation (3), the gas is reformed into a reformed gas D' containing hydrogen as the main combustible component.

This reformed gas D' is supplied to the reformed gas flow rate control valve 2.
The gas is supplied to the gas engine 26 together with the combustion air Ar through the gas cylinder 4, and is ignited by the spark plug 25 to cause combustion.

Next, operation control of the device according to the present invention will be explained.

■ Temperature control of methanol reforming reaction Since methanol steam reforming reaction and methanol decomposition reaction are both endothermic reactions, if the reaction temperature in the catalyst layer is too low (for example, 200°C or less), the reaction rate will decrease and methanol conversion will decrease. rate decreases, the reformed gas components (H2, Co, etc.) of the fuel supplied to the gas engine decrease, and the unreacted methanol component increases. Note that Table 1 below shows the components of the reformed gas.

Table 1 - Produced gas - Catalyst...Cu -Z n -Cr
On the other hand, if the reaction temperature is too high (for example, 350° C. or higher), the catalyst tends to deteriorate, and furthermore, it is not preferable from the viewpoint of the strength of the constituent materials of the reformer.

Therefore, it is necessary to maintain this reaction temperature within an appropriate temperature range.

On the other hand, the exhaust gas temperature of the gas engine 26 changes as shown by curve 12 in FIG. 3 depending on the engine load. For this reason,
In this device, the temperature of the catalyst layer is detected by a temperature sensor 3°, and the amount of exhaust gas flowing into the methanol reformer 31 is controlled by a temperature controller 29 and a control damper 28 so that this value becomes an appropriate value. At this time, if the exhaust gas H' that has flowed to the bypass duct 34 is discharged directly to the chimney 36, it is not desirable from the standpoint of effective energy use, so the reformer 31 and the heat exchanger 32 are bypassed and the exhaust gas H' is placed before the exhaust heat recovery boiler 35. #l: After effectively recovering the heat, it is discharged from the chimney 36.

The appropriate temperature range of the methanol reforming reaction temperature is slightly different between the methanol steam reforming reaction and the methanol decomposition reaction.

Figure 2 shows the relationship between methanol conversion and reaction temperature when using a Cu-Zn-Cr catalyst.
It can be seen that the methanol steam reforming reaction has higher activity at low temperatures than the methanol decomposition reaction. Performance varies slightly depending on the type and amount of catalyst, but if a Cu-Zn-Cr catalyst is used and the operation is performed at LH3V = 1.0 h-1, the appropriate reaction temperature for the steam reforming reaction is 25
The temperature is preferably 0°C to 300°C, and in the case of a methanol decomposition reaction, 300'C to 350°C.

The following information can be read from Figure 2.

■ Reaction temperature (e.g. 280°C), catalyst amount (e.g. LH
SV=3h-1), the conversion rate of methanol steam reforming (approximately 99%) is higher than the conversion rate of methanol decomposition reforming (approximately 68%).

■ The amount of catalyst (for example, LHsV=:3h'') is the same,
If the conversion rate is to be the same (for example, 99%), the reaction temperature for methanol steam reforming must be 280°C and the reaction temperature for methanol decomposition reforming must be 350°C. It requires a large area and high heat resistance.

■ If the reaction temperature is the same (e.g. 280°C) and the conversion rate is to be the same (e.g. 99%), the amount of catalyst for steam reforming is 3 h-1 and for decomposition reforming it is approximately 1.0 h-1. The latter requires about three times as much catalyst.

That is, as a methanol reformer, it can be said that the methanol steam reforming method is more advantageous in terms of device QAT than the methanol decomposition reforming method.

■ Pressure control of methanol reformed gas The methanol reforming reaction, whether it is a decomposition reaction or a steam reforming reaction, is a reaction that increases the number of moles, so the reaction is accelerated at lower pressures, and lower pressures are also better for equipment manufacturing. Operation at as low a pressure as possible is advantageous because it is easy and inexpensive.

Specifically, the reformed gas flow rate control valve 24 and air valve 23 of the fuel gas supply amount control device G are operated by the output signal to the gas engine 26, and the excess air ratio is set to a predetermined value (for example, in the case of lean combustion). , is set to 1.8). Furthermore, even if the flow rate of the reformed gas D' increases or decreases, the reformed gas pressure at the exit of the reformer remains constant (for example, about 0.
2 kg/cdG), the reformed gas pressure detector 13 detects the pressure, and the methanol vapor flow rate control valve 15 is operated via the controller 14 of the methanol supply amount control device MF, so that the pressure is maintained at 2 kg/cdG). The amount of methanol vapor supplied to is controlled.

■ Control of the amount of steam added If the methanol steam reforming reaction (equation (3)) or the methanol decomposition reaction is caused by the addition of steam (equation (2)), the methanol flow rate detector 12. Ratio setting device 16° Steam flow controller 17
and the water vapor flow rate control valve 19, the molar ratio m of the water vapor flow rate to the methanol vapor flow rate becomes O<
Control is performed so that m=1.2.

In addition, in the methanol reforming reaction, when the molar ratio m is less than 1.0, a decomposition reaction occurs;
When 1.0≦m≦1.2, a steam reforming reaction occurs.

Also, the setting of this molar ratio, that is, whether to cause a decomposition reaction or a steam reforming reaction.

It can be used depending on the operating status of the gas engine cogeneration system.

That is, when the steam demand for the process is large, the ratio setter 16 is set to O<m<0.9 in terms of molar ratio.

In this case, it is more desirable that the molar ratio m is approximately O to cause a complete decomposition reaction, and the reaction temperature is desirably set at 300 to 350°C. This is because when the reaction temperature is low, the methanol decomposition efficiency (conversion rate) is low.

In addition, when the steam demand for the process is small, or when the NOx value or C○ value in the exhaust gas is kept extremely low, the ratio setting device 16 is set to m = 1. ○
~1.2 and operate with steam reforming reaction. At this time, it is desirable that the reaction temperature be set at 250 to 300°C.

■ Control of steam pressure Since the amount of steam generated by the Nl-heat recovery boiler 35 depends on the gas engine load, the steam pressure is detected by the steam pressure detector 20 and the steam flow control valve 22 is operated via the controller 21. By this, the steam pressure is controlled to be constant (for example, 2 to 7 kg/ci G).

Further, the water level of the boiler 35 is controlled by a method conventionally used in boilers and the like.

■ Control of methanol vapor pressure The methanol steam generator 3 uses jacket cooling exhaust heat of the gas engine 26 as a heat source, and controls the methanol vapor pressure by operating the hot water flow rate control valve 5 via the pressure detector 9 and pressure controller 10. is constant M(
For example, it is controlled to be approximately 0.5 kg/txl G).

Further, water level control is performed using a method conventionally used in boilers and the like.

Next, the methanol reforming gas engine according to the present invention
The various characteristics of the cogeneration system will be explained in comparison with a conventional gas engine cogeneration system that uses city gas as fuel.

Figure 3 shows various characteristics of the device of the present invention, and shows a gas engine cogeneration device with an output of 100 KW (gas engine rated output = 125 psh, rotation speed = 1
50Orpm, compression ratio = 12, supercharger = none, excess air ratio = approximately 1.8).The solid line is the value when methanol cracked reformed gas is used as fuel, and the dotted line is methanol The respective values are shown when steam reformed gas is used as fuel.

Also, Figure 4 shows the output 1 using city gas (13A) as fuel.
00KW gas engine cogeneration system (
Rated output = 125 ps h, rotation speed = 150Qr
pm, compression ratio=12. No supercharger, excess air ratio = approx. 1
．． This is the actual measured value in 2).

Furthermore, Table 2 shows methanol decomposition reforming and methanol steam i
This is a summary of the comparison.

Based on FIGS. 3, 4, and Table 2, the performance values at 100% load are compared as follows.

Power generation efficiency A normal gas engine that uses city gas (13A) as fuel has a power generation efficiency of about 31%. On the other hand, when cracked reformed gas is used, the power generation efficiency is approximately 39%, and when steam reformed gas is used, it is approximately 39.5%, which means that the power generation efficiency is approximately 26% and 27%, respectively. %Rise.

The reason why the power generation efficiency increases more than the heat increase of each reformed gas is because the C-in reformed gas is a hydrogen-rich gas.
Pre-ignition occurs at a low excess air ratio equivalent to that of 13A gas, so it is necessary to increase the excess air ratio and perform lean combustion; (b) As a result of lean N combustion, the combustion temperature in the engine cylinder increases. This is because engine efficiency increases because the amount of heat escaping from the cylinder wall to the jacket cooling water decreases, Table 2 Comparison of methanol decomposition reforming and methanol steam reforming, and combustion deterioration does not occur.

Furthermore, the reason why the steam reforming method has slightly higher power generation efficiency than the decomposition reforming method is due to the lower combustion temperature and the higher heat gain of the reformed gas, as shown in FIG.

(2) NOx emission concentration The NOx emission concentration in a gas engine is due to thermal NOx, and is approximately 2. It is about OOppm.

On the other hand, in the case of 1 cracking reforming, the NOx emission concentration is about 500 ppm, and the steam reforming (steam/methanol vapor ratio =
1.2) has a low NOx effect of about 300 ppm.

This is because lean combustion is possible and the combustion gas temperature is low, and in the case of steam reforming, the reformed gas contains unreacted excess H20 gas, so it is much more effective than in the case of cracked reformed gas. It has a low NOx effect.

(3) C○ emission concentration Approximately 1. The CO concentration of OOOPPm is about 700 ppm for methanol decomposition reformed gas, and about 200 ppm for methanol steam reformed gas, so the emission concentration is low.

The reason for this is that city gas (13A) is methane gas (CH4
) is the main component, and methane gas has a low oxidation reaction activity among gas fuels, making it difficult to burn, and a relatively large amount of C○ acid components are detected as unburned components during the combustion process.

On the other hand, reformed gas is a gas rich in hydrogen (H2), has high oxidation reaction activity, and is completely combusted within the engine cylinder. However, the cracked and reformed gas contains about 33% CO, and unburned components of the co-acid component are inevitably generated. As a result, approximately 4% of C○ acid components are present in the steam reformed gas, and some CO is detected as unburned components.

The performance comparison of the 100KW gas engine cogeneration system was specifically shown above, and the methanol reforming type gas engine cogeneration system of the present invention has higher power generation efficiency than the conventional system using city gas (13A) as fuel. It can be seen that the engine exhibits much superior performance in terms of exhaust gas characteristics.

In addition, the method using methanol steam reformed gas as fuel, which is one of the devices of the present invention, has better power generation efficiency and exhaust gas characteristics (NOx .

CO) becomes much better.

Furthermore, in the apparatus of the present invention, in a situation where it is desired to extract more steam energy, it is possible to switch to the cracked and reformed sludge type operation to meet the steam load requirement.

(Effects of the Invention) As mentioned above, in the gas engine cogeneration system using reformed methanol gas as fuel of the present invention,
Methanol, which is an alternative energy source to oil and LNG, will be used as an energy source, and the exhaust heat of the gas engine will be used to reform methanol, and the heated reformed gas will be combusted to drive the gas engine generator. As a result, electric energy can be obtained with higher efficiency than when using conventional city gas as fuel, and overall energy use efficiency is improved by extracting hot water energy and steam energy using waste heat. I can do it.

Furthermore, in the device of the present invention, compared to the case where city gas is used as fuel, it is possible to further reduce the amount of N○X and C○ in the exhaust gas, making it possible to prevent environmental pollution. .

Furthermore, in the present invention, even when the steam load increases, the amount of steam added to the methanol vapor can be easily coped with by using the steam addition amount control device F.

In addition, the present invention provides the following excellent effects.

■ The pressure of the reformed gas is detected, and the output of this pressure detector is used to control the opening and closing of the control valve for the flow rate of methanol vapor supplied to the methanol reformer via the controller. Almost no fluctuations occur, and reformed gas can always be supplied to the gas engine in a stable state.

■ Detects the temperature of the catalyst layer in the methanol reformer, and uses the detection signal to adjust the amount of exhaust gas flowing into the reformer via the control damper, and also directs the bypassed exhaust gas to the inlet side of the heat recovery boiler. Since the structure is such that a stable reforming reaction can be performed at a constant temperature, exhaust heat can be recovered more efficiently.

■ The methanol vapor pressure is detected by a pressure detector, and the detection signal is used to control the amount of jacket cooling water flowing into the methanol heater via the controller, so the methanol vapor pressure is always maintained at the desired value. At the same time, the exhaust heat of the jacket cooling water can be more effectively recovered by the hot water generator.

As mentioned above, the present invention has excellent practical effects.

[Brief explanation of the drawing]

Figure 1 shows a methanol reforming gas engine according to the present invention.
1 is an overall system diagram of a knee generation device. FIG. 2 is a diagram showing the relationship between reaction temperature and methanol conversion rate in methanol reforming reaction. FIG. 3 shows actually measured values showing the relationship between the engine load of the gas engine, exhaust gas temperature, NOx concentration, CO concentration, and power generation efficiency in the apparatus according to the present invention. Figure 4 shows a conventional city gas (13A) type gas engine.
These are actual measured values showing the relationship between the engine load, exhaust gas temperature, NOx concentration, CO concentration, and power generation efficiency of the knee generation device. A Gas engine device B Methanol steam generator B' Methanol steam C Hot water generator D Methanol reformer Catalyst layer temperature detector Raw material gas superheater Exhaust heat recovery boiler Methanol reformed gas Exhaust heat recovery boiler device Steam addition amount control device Raw material Gas Fuel Gas Supply Control Engine Exhaust Gas Engine Jacket Cooling Water Methanol Steam Generator Jacket Cooling Water Control Valve Hot Water Generator Methanol Steam Pressure Detector Methanol Steam Pressure Controller Ratio Setter Steam Flow Controller Steam Control Valve Gas Engine Generator Exhaust Gas Inflow Adjustment damper temperature controller Methanol reformer Fig. 2 Warp temperature [゛C]

Claims (7)

[Claims] (1) A gas engine device (A) that uses reformed methanol gas as fuel; A generator (27) driven by the gas engine device (A); A jacket cooling water (W) of the gas engine device (A) a methanol steam generator (B) that is heated; a hot water generator (C) that is heated by the jacket cooling water (W); and a methanol reformer (D) that is heated by the exhaust gas of the gas engine device (A). ) and; an exhaust heat recovery boiler device (E) provided downstream of the methanol reformer (D); and a predetermined amount of the exhaust heat recovery boiler device ( A steam addition amount control device (F) that adds steam from the methanol reformer (D); and a steam addition amount control device (F) that adds steam from the methanol reformer (D); A) A methanol reforming type gas engine cogeneration system consisting of a fuel gas supply control device (G) that supplies fuel gas to A). (2) The steam addition amount control device (F) is controlled by the steam control valve (19) based on signals from the methanol steam flow rate and steam flow rate ratio setter (16) and the ratio setter (16)
2. The methanol reforming gas engine cogeneration system according to claim 1, further comprising a steam flow rate controller (17) for operating the meter-ethanol reforming gas engine cogeneration system. (3) A methanol reformer (D) is provided with a raw material gas superheater (32) on its downstream side, and the exhaust gas inflow rate is controlled by signals from the catalyst layer temperature detector (30) and temperature detector (30). The methanol reforming gas engine cogeneration system according to claim 1, further comprising a temperature controller (29) that operates the adjustment damper (28). (4) The methanol steam generator (B) is controlled by the engine jacket cooling water (W) control valve (
5) to operate the methanol vapor pressure controller (10
2. The methanol reforming gas engine cogeneration system according to claim 1, wherein the methanol reforming gas engine cogeneration system is configured to include the following. (5) Use methanol as fuel, reform it into hydrogen-rich gas fuel by the methanol reformer (D), and supply this methanol reformed gas to the gas engine device (A) to power the generator (27). In a methanol reforming type gas engine cogeneration method in which the methanol is reformed and steam is generated by the engine exhaust gas (H), the engine jacket cooling water of the gas engine device (A) is rotatably driven. Methanol is evaporated using the exhaust heat of (W) to obtain methanol vapor at a constant pressure, and hot water is generated by recovering the exhaust heat of the cooling water, and steam is generated by recovering the exhaust heat of the engine exhaust gas. part together with the methanol vapor in the exhaust heat recovery boiler device (E)
Supplied to the methanol reformer (D) installed on the upstream side of
A methanol reforming gas engine cogeneration method in which a reformed gas (D') at a constant pressure is generated and supplied to a gas engine device (A). (6) Methanol reformer (D) with methanol vapor
The methanol reformer according to claim (5), wherein the amount of steam supplied to the methanol vapor load is a variable amount of at least about 2 or less in molar ratio to the amount of methanol vapor, and the amount of steam supplied to the steam load is made variable. type gas engine cogeneration method. (7) By adjusting the amount of engine exhaust gas flowing into the methanol reformer (D),
) by adjusting the temperature of the catalyst layer in the methanol reformer (D) to a constant value and the flow rate of methanol vapor supplied to the methanol reformer (D). The methanol reforming type gas engine cogeneration method according to claim (5), wherein the pressure in step (') is controlled to a constant value.