JPS58211511A - Composite power generating plant using gasifyed coal - Google Patents

Abstract

PURPOSE:To improve a load responsing characteristic by a method wherein an electrolytic device for water is arranged in a plant for driving a gas turbine with fuel gas produced by a coal gasification furnace etc. and the oxygen and hydrogen generated in the electrolytic device are fed to the gasification furnace and the gas turbine. CONSTITUTION:In a composite power generating plant, a feeding coal 17 produced by grinding or breaking coal by a coal pre-processing device 1 and oxygen 19 produced from air 18 by an oxygen producing device are fed to a coal gasification furnace 3, coal gas produced at the coal gasification furnace is made to a purified gas 21 through a gasification furnace heat recovery device 4 and a fuel gas purification device 5 and then the gas 21 is fed to the combustion unit of the gas turbine 6. In this case, a water electrolytic device 23 is newly added, the water pressurized by a water feeding pump 26 is electrolyzed to produce a high pressure oxygen and hydrogen. The oxygen and hydrogen are stored in each of storage tanks 24 and 25 and properly supplied in response to the requirement of the gasification furnace 3 and the combustion unit of the gas turbine.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coal gasification combined cycle power plant that performs gasification using oxygen pipes, and particularly to a plant that provides a suitable load response to a deer load request button.

A typical conventional example of a coal gasification power generation plant using an oxygenated coal gasification furnace is shown in Fig. 1.
Based QasificatioW-Combi
ned-Cyde8system performance
e 5tudies” (June.

1980), coal gasification using a current gas turbine in an oxygen oxidation entrained bed furnace.

It performs combined power generation, and includes a coal pretreatment device t1, an oxygen production device 2, a coal gasifier 3, a gasifier heat recovery boiler 4,
Fuel gas purification device f5, gas turbine 6, exhaust heat recovery boiler 7, steam turbine 13, condenser 14, water supply pump 15
It consists of , the gas turbine exhaust heat recovery boiler 7 includes an economizer 8, an evaporator 9, a drum 10,
It is composed of a super heater 11 and a reheater 12.

The coal is subjected to pretreatment such as pulverization in the coal pretreatment device ff, and becomes feed coal 17 to the coal gasifier 3.

In the brewer production equipment a2, air 18 is separated at a low temperature, and 1 UiiL of oxygen 19 is supplied to the coal gasifier 13 as an oxidizing agent. Since the crude gas generated in the coal gasification furnace has a high temperature of 20 degrees, it exchanges heat with the steam plant water supply in the gasification furnace heat recovery boiler 4 to become low temperature and enters the fuel gas purification device 5. Purified gas 21 that has been desulfurized in the fuel gas purification device is supplied to the gas turbine 6 as gas turbine fuel. The exhaust gas after being subjected to #5m in the gas turbine 6 enters the exhaust heat recovery boiler 7, generates steam, and is sent to the steam turbine 13.
to drive. The feed water leaving the condenser 14 of the steam turbine is pressurized by the feed water pump 15, heated by the gas purifier 5, and then divided into two parts, one of which is sent to the gasifier heat recovery boiler 4.
The other part is led to the exhaust heat recovery boiler 7. The water supplied to the exhaust heat recovery boiler t7 is heated by an economizer 8, heated by a drum, and evaporated by an evaporator 9. The steam from the gasifier heat recovery boiler 4 and the steam from the exhaust heat recovery boiler drum 10 are mixed, superheated by the super heater 11, and enter the high pressure steam turbine. Cold reheating of the high pressure turbine is reheated by the reheater 12 to drive the medium pressure hot air turbine. It has the disadvantage of poor load characteristics and load response, and is dominated by coal pretreatment equipment, oxygen production equipment, coal gasifier, and fuel gas purification equipment systems. In particular, oxygen production equipment has poor partial load characteristics and is difficult to start up. The downside was that it took a long time.

An object of the present invention is to provide an oxygen-oxidized coal gasification a-combined brazing flant that can be operated satisfactorily in response to power load demands.

It is carried out in a similar way to the decomposition of water.

2H”ki2e=)(.

20H-=H, 04--0. +2e Overall, 2 hours of electricity, Hl O” H
t↓−〇.

becomes. That is, theoretically, 1000A-hr″F
``448 tons of hydrogen, 224 tons of oxygen (latm, 20°C
) is obtained, the water-retaining fIl theoretical decomposition voltage is 1.226V (
Using this at 25°C), the theoretical sorption for l kwh is calculated, hydrogen 365t, oxygen tg3z (tatm
20°C). In reality, the theoretical component w414L pressure energy efficiency two-section flow efficiency x □ Bath voltage, the energy efficiency is 57-78 at a bath voltage of 1.9-2.6V.
It is said that the decomposition voltage does not change at about 700 atat. (Ishino, Tamura, Mizuguchi “Electrolysis Industry” Nikkan Kogyo,
835.2) Here, assuming that the energy seedling is 70% and calculating the generation rate per lkw of hydrogen and acid amount, hydrogen 5.9
5X10-6 kg/s/kw oxygen 4.737X1
0=kg/s/kw.

On the other hand, in the oxygen production equipment used in Figure 1, the electricity required for the gasifier is 89.46 kg/SK, and the electric power is 13.
Requires 3.12MW and 6.72X10-'kg/s/k
Judging solely from the viewpoint of oxygen production, it is more efficient to produce oxygen using an oxygen production device.

However, if we focus on the fact that the decomposition voltage does not change depending on the pressure of water, it is possible to obtain high-pressure hydrogen and oxygen by electrolyzing high-pressure water, which is advantageous for storage. It is possible to use it as fuel with a kilogram of fuel, and this point should also be noted.

In a coal gasification combined cycle power generation plant, even when there is no visual load requirement such as at night, the minimum possible load KPM is used to electrolyze water using surplus electricity and generate high-pressure hydrogen and oxygen. If the coal gasification combined cycle plant is left behind and stored, even if the conventional coal gasification plant is unable to meet the demand for visual power, the coal gasification combined cycle power plant will be able to meet the demand. An example is explained in Fig. 2.
In the embodiment shown in FIG. 2, the typical conventional configuration example shown in FIG.
, a hydrogen supply control valve 29°30, and a calorific value measuring device 31 are also added.

Water is pressurized by the water supply pressurizing pump 26 and supplied to the water electrolyzer 23, and the pressurized water is electrolyzed using surplus power at night without stopping the plant. High pressure oxygen generated by electrolysis will be stored in the oxygen storage tank 24 via the oxygen supply control valve 27, and high pressure hydrogen will be stored in the hydrogen storage tank 25 via the hydrogen supply control valve 29. When a request occurs, the power supply to the water electrolysis device 23 is stopped and the control valves 27, 28, 29, 30 are closed. When a fluctuating demand for power occurs and the oxygen taizou plant cannot meet the load response, the oxygen supply +)t control valve is controlled;
Oxygen is supplied from the oxygen storage tank 24 to the gasifier 3.

Furthermore, the calorific value of the gas turbine fuel gas decreases significantly during load response, partial load, and the like. '+I, the hydrogen supply control valve 30 is set to 14 by No. 1B of the calorific value measuring device 131.
1IJ #L hydrogen is supplied to keep the calorific value of the gas turbine fuel gas constant.

According to the present invention, it is possible to suppress a decrease in the calorific value of the gas turbine fuel gas, and another embodiment of the present invention, which has the effect of stabilizing the combustion pressure in the gas turbine combustor, will be described with reference to FIG.

In the embodiment shown in FIG. 3, the typical conventional configuration example shown in FIG.
B, hydrogen supply control valves 29, 30, oxygen, steam mixer 32
, water-cooled wall combustor 33. This includes a combustor evaporator drum 34 and a high temperature steam turbine 35.

When surplus hidden power occurs at night, etc., water supplied under pressure to the water decomposition unit @23VC is electrolyzed by the water supply pressure pump 26 using surplus power pressure. The high-pressure oxygen produced by the pump is stored in the oxygen storage tank 24 via the oxygen supply control valve 27. Further, high-pressure hydrogen is stored in the hydrogen storage tank 25 via the hydrogen supply control valve 29.

When a power load request occurs, the power supply to the hydroxyl decomposition unit h123 is stopped, and the control valves 27.28 and 29.30 are closed.

When the power load demand becomes large and cannot be met by @WLllll of the gas turbine 6 and steam turbine 13, when the demand for load increase rate is large and cannot be met by the gas turbine 6 and steam turbine 13, the oxygen supply control valve 28 and the hydrogen supply control valve 30 are gradually opened, and the water-cooled pipe is ignited! Combustion is carried out in eight vessels 33. - On the other hand, the feed water pressurized by the steam turbine feed water pump 15 cools the high temperature steam turbine 35 and then enters the 1 combustor evaporation drum 34,
Cools the water-cooled wall combustor. The steam generated in the combustor evaporator drum is mixed with oxygen in the oxygen/steam mixer 32, and is led to the water-cooled wall combustor 331C to burn hydrogen. High-temperature steam generated by combustion enters the high-temperature steam turbine 35 to perform work, and is returned to the condenser 14. In addition, 1 in the figure
6 is a coal flow, and 22 is a gas turbine exhaust flow.

According to the present invention, when the power generation capacity of the gas turbine and the steam turbine is planned to be lower than the expected maximum required load, and the required load exceeds the power generation capacity, the high temperature steam turbine can be operated to meet the required load. be.

According to the present invention, in an oxygen oxidation coal gasification combined cycle power generation plant, it is possible to store surplus power when there is no power demand such as at night, and the stored energy can be used in response to power demand. This has the effect of allowing better operation.

[Brief explanation of the drawing]

Fig. 1 is a system diagram of a coal gasification combined cycle plant using a conventional oxygen oxidation coal gasifier, and Figs. 2 and 3 are system diagrams of a coal gasification combined cycle power plant according to an embodiment of the present invention.

Claims (1)

[Claims] 1. A combined coal gasification + J arousal plant characterized by being equipped with a water electrolyzer, an oxygen storage tank, and a hydrogen storage tank in a combined power generation plant using an oxygen-oxidized coal gasification furnace.