JPS5882006A - Device for converting heat into work - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention involves evaporating a fluid such as water under pressure in a boiler and synchronously evaporating it under pressure in order to thermally generate electrical energy for power generation by converting heat into work. A closed thermodynamic circuit can be used, with expansion in a steam turbine connected to a generator, which is then condensed and cooled before being returned to the boiler. Heat for vaporization is generated by burning a fuel such as a hydrocarbon in the presence of a suitable amount of combustion air. Although the thermodynamic efficiency of such steam-driven turbine generator units is relatively good, the cost of the equipment is very high, which is much lower than the cost per kilowatt-hour supplied by this type of thermal power plant. This shows that depreciation costs account for a relatively large proportion.◎The torque required to drive the large-power generators can also be supplied by gas turbines with an open thermodynamic circuit. This open thermodynamic circuit uses air mixed with a fuel such as natural gas or liquid petroleum as the thermodynamic medium. In this type of device, air taken from outside is compressed in a compressor and the resulting gas is expanded as it passes through a turbine. A compressor and a generator are connected to the shaft of this turbine.

The specific consumption (per kilowatt-hour supplied) of a gas turbine unit is much higher than that of a steam turbine unit. However, the investment cost is very low, which is why gas turbine units are often used for peak load generators or standby generators in thermal power plants. One is to limit the inlet temperature of one turbine to about 800 C, or about one-third of the commonly used combustion flame temperature, to ensure mechanical robustness and adequate lifespan of the turbine blades. This is because it is considered desirable. In conventional gas turbines, limiting the turbine inlet temperature is achieved by diluting the combustion gases exiting the combustion chamber with approximately four times the amount of fresh compressed air; The entropy of the gas increases significantly as a result of purification loss.Furthermore, the energy required to drive the compressor at this time is five times greater than the energy required to compress air. Although the energy absorbed during compression is theoretically returned during expansion, the changes described above are far from reversible in practice, and large dilutions in industrial gas turbines reduce their efficiency. let Finally, the gases exhausted by the turbine are relatively hot, and usable energy is thereby further lost.

In order to reduce the amount of energy that is lost, so-called mixed thermal power plants have been proposed, which have a dilution gas turbine combined with a steam turbine unit. A hot oxygen-enriched gas mixture forms the combustion gas or a part thereof, in which the fuel fed to the boiler of the steam turbine unit burns. A significant portion of the residual energy of the gas is recovered at the shaft end of the steam turbine. And in this way, a more efficient use of the fuel supplied to the gas turbine is achieved with a relatively inexpensive gas turbine unit than would be obtained if it were not combined with a steam turbine unit. - Considering the relative investment costs of the gas turbine S unit and the steam turbine unit, it is advantageous for the contribution of the above-mentioned type of mixing device to the output of the gas turbine unit to be as large as possible compared to that of the steam turbine unit. . However, according to the theoretical findings K, the maximum value of this contribution achieved when the exhaust gas of the gas turbine unit provides the entirety of the fuel supplied to the boiler of the steam turbine unit is It is an object of the present invention to provide a new device for converting heat into work which eliminates the above-mentioned drawbacks of the prior art.According to the invention , two gas turbine units each having a combustion chamber and a turbine arranged to be driven by gas supplied from the combustion chamber, and another gas turbine unit coupled to receive gas exhausted from each of the turbines. A device for converting heat into work is provided which includes a combustion device and is characterized in that one, but not both, of the combustion chambers are provided with a device for preventing complete combustion of the fuel supplied thereto.

The excess air supplied to one turbine and the excess fuel supplied to another turbine dilute the combustion gases supplied to the turbine from the combustion chamber and lower their temperature, i.e. this temperature is not exactly normal. The temperature is kept below the temperature corresponding to the composition ratio, thereby reducing the risk of damage to the turbine blades due to overheating. This new arrangement II also has the ability to compress the amount of air to a maximum of II! %Fuel burned in the melting chamber o
This is advantageous from the point of view of efficiency of compressor use, since it can be determined in relation to only will be collected by the time the Higher flame temperatures can be used in this subsequent combustion chamber.

For purposes of illustration, embodiments of the invention will now be described with reference to the drawings.

The device according to the invention, shown in FIG. 2KM, has a steam turbine unit 10, a first gas turbine unit 11 and a second gas turbine unit 12.

Steam turbine unit 10 is of conventional construction.

It has a high-pressure turbine stage 15 and a low-pressure turbine stage 16, which share a common transmission shaft 1 connected in a synchronous manner.
7 is cooled and condensed in the expanded steam condenser 1B in the turbine housing 16, and then the pump 2
0 to conventional water heaters 21 and 22, in which they are heated by steam extracted from the stages of the low pressure turbine stage 140. The water heated in the reheater then passes into the mailer 19. Boiler 19 is superheater 2
3. Resuperheater 24.11 Attenuator 25 and exhaust gas cooler 2
The water coming from the reheater 21 first passes through the exhaust gas cooler 26 and then passes through the reheater 22 as shown in FIG.
It can also be changed into water and synergy. This steam is then partially expanded in high pressure turbine stage 15 and then in resuperheater 2
4 and then finally expands in the low pressure turbine stage 16.

The first gas turbine unit 11 has an air compressor 31, a combustion chamber 62, and a turbine 33.

Outside air is supplied through the compressed *31KF1 input rod duct 54. The compressor is driven by a turbine 55 via a transmission shaft 35. The transmission shaft '55 can be coupled to the transmission shaft 17 of the steam turbine unit, or can be connected to an independent synchronous generator (I
iii3 (not shown).

A part of the air compressed by the compressor 31 is transferred to the supply pipe 5
6 to ensure the fuel efficiency of the liquid or gaseous fuel supplied to the combustion chamber 52.

The remainder of the compressed air is used to dilute the fuel gases to maintain the turbine inlet temperature at a suitable value.

The mixture of hot gases expands as it passes through turbine 33. The gas discharged after expansion, which still has a large proportion of the insignia due to its dilution, is sent to the boiler 19 of the steam turbine unit in a pipe 37 for use as fuel air.

The second gas turbine unit 12 has a combustion chamber 42 with a catalytic lining (not shown) for precisely limiting the combustion of the fuel supplied to it by a supply pipe 46, and a compressor 41 with a It differs significantly from the previously described turbine unit 11 in that it is designed to provide a relatively small flow of combustion air just needed to ensure partial combustion according to the reaction equation. Steam-injected stomach (
(not shown) is provided to prevent soot formation within the compressor 41. The compressor 41 and the turbine 43 can be connected by a common transmission shaft 45 that can drive a synchronous generator. The machine may be driven independently by a variable speed drive charge. The gases discharged from the expansion ridge turbine 43 are passed to the boiler 19 through a tube 47 having a /(- (not shown) at the end. This gas can still have a high fuel consumption, which in this case is all of the fuel supplied to the boiler 9. Of course, the respective gas flow rates Fi final combustion up the tubes 67 and 47 The graph in Figure 1 shows that the flow t of combustion air supplied to an industrial gas turbine from a combustion chamber in which fuel is burned at a constant rate is
A plot of turbine inlet temperature versus Q is shown. The peak of the curve corresponds to the maximum combustion temperature t, K. This temperature is obtained at the air flow rate Q, which corresponds to the normal composition ratio of combustion air and fuel for a complete combustion reaction, as shown by the following equation.
1) H2O2 Therefore, to ensure complete combustion, reduce the flow rate Q to Q.

It is necessary to apply high pressure during papermaking, and the temperature at the turbine inlet is a
The ninth K to prevent the value from exceeding the value tN near o o'c is to prevent excess air from reaching the gas turbine ennit 11 mentioned above.
The combustion chamber 52 is passed through. Therefore, this enit can be referred to as a diluted gas turbine unit.The flow rate of such air is indicated by QD which is slightly larger (approximately 5 times) than the flow rate Q of normal composition.

However, according to the graph in Figure 1, the flow rate Q of the normal composition,
It can be seen that even with incomplete combustion of fuel due to a smaller air flow rate Qep, the inlet temperature of the t-large tanibin can be prevented from exceeding the safe temperature tN.

If this is the method used in the second gas turbine unit 12, this unit may be referred to as a partially fired gas turbine unit. Combustion can be achieved in the unit of this strain by the following reaction・CnH, n+2+n02nc
O+ (N+1)H.

In order to ensure that the partial combustion follows the above-mentioned reaction equation, a suitable catalytic coating coats the inner walls of the combustion chamber and steam can be injected into the combustion chamber air to avoid the formation of soot.

As shown in FIG. 1, the flow rate Qa of combustion air passing through the compressor of a partially-combusted φ-type gas turbine unit is much smaller than the flow rate Qn flowing through the dilution lid gas turbine unit. Therefore, the mechanical power absorbed by the air compressor in the first unit is less than the amount of power provided by the expansion of the hot gas, which is the case in the KFi dilution type unit. 4 of the power provided by expansion.

The construction of both gas turbine units is essentially harmonious.

<,'IK Both units can use gaseous fuel such as natural gas or liquid fuel sufficiently free of impurities (sulfur in #f).

Natural gas may be used as the fuel supplied to the apparatus shown in FIG. It is practically free of harmful impurities and is commercially freely available at relatively high pressures, so that before its introduction into the combustion chambers 52 and 42 the nominal static pressure should be of the order of about 10 atmospheres. No need to compress. However, the fuel can generally consist of heavy or light oil reservoirs, such as those used in industrial gas turbines.
As a result, the residual oil content of the Fi-electrode can be used as fuel. Such fuels contain sulfur-based impurities that are desirably separated upstream of the turbine blades and boiler O heat exchange surfaces of the steam turbine unit 10.

ζHere, parts of the turbine unit 12 & similar to the parts of the turbine unit 120 are indicated by the same numbers with a suffix a. In this unit j2a, undistilled heavy oil is partially supplied to the combustion chamber 42aK through a pipe 44m. This processing chamber 51 (D
It is desulfurized inside. This desulfurizing agent reacts with the hydrogen sulfide liberated by incomplete combustion in the combustion chamber 42a to form a compound, which is separated by a dust remover 55 through which the gas exiting the treatment chamber 51 passes. The sulfides separated by the vessel 5sK are regenerated by a recirculator 54 in order to be reintroduced into the processing chamber 51 in the form of a desulfurizing agent. The purified hot gas then passes through outlet 55 to turbine 45a.
expands in the inlet 19 through the delivery passageway 47 a
is finally burned inside. In order to ensure that the entire system is operated only on relatively cheap non-distilled fuel, a portion of the purified and combustible gas flowing to the outlet 55 of the deduster 53 is supplied to the turbine 43m, and this gas is The remaining part can be supplied to the combustion chamber 32 of the dilution type turbine unit 11 ◎Along with this, a part of the combustion chamber 4
Although the flow 11 of unrefined fuel that must be supplied to 2m increases and the flow rate of air through the pressure Ii$41m1 has to be adjusted accordingly, the arrangement of the turbine unit 11 remains essentially unchanged. It remains as it is.

Embodiments other than those described and illustrated above are also shown. For example, the turbine of a partially fired gas turbine unit 12.12a actually has two stages, and the part of the gas supplied to the turbine consists of two stages. The remainder of this gas may be expanded in the first stage and then further expanded in a dilution gas turbine unit. Compression may be achieved in two or multiple stages. It is proposed herein to cool the air between one stage and the next. This reduces the work involved in compression and cooling can be achieved by heat exchange with the fuel used to generate the gas.

In all of the nine embodiments described above, the gas discharged from the part-combustion mold gas turbine and the gas discharged from the dilution type gas turbine are each independently supplied to the combustion chamber of the boiler in which fuel is combusted. In another embodiment, the combustion of the gases discharged from the turbine is used for purposes other than heating the boiler, and in other embodiments the combustion of the gases discharged from the partially fired molded gas turbine is used to fuel the dilution gas turbine unit. Used as fuel inside the chamber.

This invention can be integrated as follows.

1) The device listed in P in the scope of claims in which the device for preventing complete combustion of the supplied fuel consists of the catalyst lining of the combustion chamber (21) The device according to claim I!tI or the above (11), wherein a gas purification device is provided between the combustion chamber and the corresponding turbine.

+31 A claim in which each of the combustion chambers is connected to be supplied with air by a compressor, and the compressor is connected to be driven by a turbine driven by gas generated from the combustion chamber, (1), (2) above
The device described in any of the above.

(Either one of the 41 compressors has two stages, and a heat exchanger is placed in the passage that advances the fuel to the combustion chamber, and a heat exchanger is used to exchange heat between the air between the stages and the fuel that goes to the combustion chamber.) The device according to (3) above, which is provided with a device for guiding.

15) Apparatus of claim or any of said fi+ to (4) in which a separate combustion φ apparatus is provided to heat the boiler.

[Brief explanation of drawings]

Figure 1 is a graph showing the relationship between the flow rate of combustion air supplied to an industrial gas turbine from a combustion chamber that burns fuel at a constant speed and the temperature at the turbine inlet, and Figure 2 shows a graph showing the relationship between the turbine inlet temperature and the temperature of the turbine. FIG. 3 is a diagram showing a modification of the device of FIG. 2; FIG. In the figure, 10 is a steam turbine unit, 11a is a dilution type gas turbine unit, 12 is a partially fired molded gas turbine unit, 15#i high pressure steam turbine stage, 16 is a low pressure steam turbine stage, 18 is a compressor, 19 is a boiler, 20 is a pump, 21.22 reheater, 23 is a superheater, 24 is a resuperheater, 25 is an economizer, 26 is an exhaust gas cooler, 31 is an air compressor, 32 is a combustion chamber, 3S is a turbine, 41 is a compressor, 4
2 is a combustion chamber, and 43 is a turbine. No. 1 Ward Chrysanthemum Figure 3 Procedural Amendment (Method) November 24, 1980 Dear Commissioner of the Japan Patent Office 1, Indication of the Case 1986 Patent Application No. 186905 2, Title of Invention Apparatus for converting heat into work 3, Relationship with the case of the person making the amendment Patent applicant 4, agent 105 Address Bussan Building Annex, 1-15 Nishi-Shinbashi, Minato-ku, Tokyo Telephone (591) 0261 Specification Statement 9. Change to J-yong 7 Okay.

Claims (1)

[Claims] It has first and second gas turbine units, each gas turbine unit comprising a combustion chamber, a gas turbine driven by gas delivered from the combustion chamber, and a gas turbine operated by the gas turbine to supply combustion gas to the combustion chamber. the first gas turbine unit o compressor is configured to supply the combustion chamber with an excess of combustion gas necessary for complete combustion in the combustion chamber; The compressor is configured to supply a small amount of e-burning gas to the combustion chamber so that complete combustion cannot be achieved in the combustion chamber, and both gases are 2-°
Bi, -=t. A device for converting heat into work, which is triggered by the fact that gas X, -B, and waste gas are both supplied to another combustion device.