JPS5954736A - Combined power generation system through fuel cracking - Google Patents

Abstract

PURPOSE:To improve the power generation efficiency by chemically converting the fuel to be supplied into a gas turbine into the secondary fuel having a high combustion energy by utilizing the waste heat energy discharged from the gas turbine. CONSTITUTION:In captioned system, fuel (a) with air (b) for combustion is combusted in a combustor 1, and a gas-turbine power generation system 2 is driven by utilizing the high-pressure combustion gas formed. Steam is formed in a waste heat boiler system 3 by the exhaust gas (c) discharged from the above- described power generation system 2, and a steam-turbine power generation system 4 is driven by said system, which is condensed into water in a condenser 5. A cracking reactor 7 constituted of a fuel preheating device and a fuel carburetor is installed in a flue in the above-described waste heat boiler system 3, and cracking (decomposition) reaction of fuel (a) is carried-out in said cracking reactor 7. Thus, the combustion energy of the fuel (a) is increased, and the power generation efficiency can be improved.

Description

[Detailed Description of the Invention] [Technique of the Invention 91 Yf Field J The present invention is a fuel cracking combined power generation system with a power generation efficiency of 7m/
Regarding the stem.

[Technical background of the invention]

Recently, a nuclear power generation system that combines a gas turbine and a steam turbine driven by its exhaust heat has been developed, which enables the effective use of clean fuel such as LNG (Fig. 9).
It is attracting attention as a new technology. Figure 1 shows the 41 dimensions of this AMj system] #! This is a Glock diagram showing the configuration, and Figure 2 is a diagram showing an example of the configuration of -B. The combustor 1 burns the supplied fuel a with the combustion amount 'Ab, and the combustion energy at - is +1L from the turbine.
Two threads are being driven. From this gas turbine
2u, equipped with a gas turbine 2a, a gas turbine 2b driven by the turbine output, and an overhead air compressor 2C for the self-combustion rough round, and has a 41q construction, and has an output e-ft- I'm chewing. But 1. The Jf turbine main power system 2 exhaust gas C is discharged through the entire flue 3a of the exhaust heat boiler 3. In this urge 3 & against boiler steam? 1. A water heater 3b and a gas generator 3C are provided so that heat energy of the non-thermal gas C can be recovered to generate steam S. This steam S is supplied to the steam turbine 4a of the main electric power system 4, and the main electric machine 4b is driven to generate a turbine output f yj
: Ij c, I+. Note that the steam S passing through the steam turbine 4a is supplied to the condenser 5,
After being cooled by the cooling water d, it is supplied to the feed water preheater 3b via the cooling water □. This results in
The steam 8 is designed to recover the thermal energy of the exhaust gas and circulate it.

FIG. 3 schematically shows the energy relationship in the system with the above configuration, where Fj is the energy of fuel a,
Ll is the energy loss in the gas turbine 2a, L! is the energy lost in the steam turbine 4&, wl, w, is the generator 2b, 4bf! : Indicates the generated energy obtained through

In this way, according to this stem, a part of the energy that could not be extracted in the gas turbine generation system 2 can be extracted in the steam turbine generation system 4, which improves the power generation efficiency and increases the combustion efficiency. ii effective utilization can be achieved.

[Problems with background technology]

However, the above system is generally developed on the assumption that LNG vaporized gas, that is, mainly methane (C) I4), is used as the fuel a. In response to this problem, attempts have recently been made to use methanol (CII, charcoal such as (river), etc., or aluminium, which is of a poor quality, as a fuel). is produced from various hydrocarbon sources such as natural gas, lime, lignite, lignite, pulp oil, petroleum coke, and wood, and is attracting attention as an alternative fuel to petroleum. It exhibits properties comparable to gasoline. It is also a highly pure oxygenated hydrocarbon compound from which impurities such as sulfur have been removed during its production, making it useful as a clean fuel.

However, while the combustion heat of methane (CI(4)) is 212.8 kQIVmol at a fast pace, the Jff of methanol (CII aOH) is 182.6.
It is as low as k(,'dg/mol).

And when the unit combustion heat ratio ♀, the water vapor production ratio is 1, and the flue gas ♀ is released! , men have problems such as a large amount of heat loss. For this reason, when methanol is used as fuel, the power generation efficiency is often low (1 day).

[Purpose of the invention□]

The present invention was made in consideration of these circumstances, and its purpose is to provide a combined power generation system comprising a gas turbine and a steam turbine driven by the exhaust heat energy of the gas turbine. -S or all of the fuel supplied to the gas turbine is chemically reacted using a part of the exhaust heat energy of the gas turbine, and converted into a secondary fuel having a higher combustion energy than the fuel, and For example, when using methanol as a fuel, the power generation efficiency is sufficiently improved, making it possible to make a highly practical fuel cracking a combination '1.
The goal is to provide a system. □ - [Application 1 of the invention] An embodiment of the system of the present invention will be described below with reference to some of the drawings.

Figure 4 shows the schematic configuration of the example system! FIG. 5 is a lock diagram showing an example of its configuration. Note that parts that are the same as those in the conventional system described above are designated by the same reference numerals, and a detailed explanation thereof will be given only partially.

The feature of this system is that the fuel 6 to be supplied to the gas turbine power generation system 2 is chemically ashed by using the thermal energy of the gas turbine 2a<041p hot gas i through the heating reactor 7. Earth, let, t, t + Kujiking reaction, by which the fuel a is converted into a secondary fuel i' with a high combustion rate and co-supplied with the gas turbine 2aIIc. be. Specifically, a fuel preheater 7& and a fuel vaporizer 7b are provided in a part 3a of the exhaust heat boiling system 3 to cause a reracking (decomposition) reaction of the waste material a, and then the secondary fuel a is &m L so as to supply it to the combustor 1.

Thus, with a system configured like this, 31st, 6th
Figure 11 schematically shows the input and output of energy. It becomes possible to reduce the efficiency to i,':i4).

That is, now, fuel a and methanol (taking Cn3 as an example), methanol is reacted in the presence of an appropriate catalyst under relatively mild reaction conditions, for example, at an atmospheric ratio of 1300°C to 400°C as Disassemble.

CH30H-+ Co + 2H2 This reaction is an endothermic reaction, and the temperature range of the reaction is
In this case, the turbine combustion exhaust gas (approximately 508° C.) can be fully utilized. However, the amount of heat produced by this combustion is
As shown in Figure 7, Lely was prepared using liquid methanol.
Ex with gaseous methanol, E with mixed gas of Co and 2H2
3, and there is a relationship of Ex < Ex < h:s. Here, the calorific value difference ΔH1, ΔH, is expressed as ΔH,=E,−E,nO ΔH,=I”;3−E, ) 0 and corresponds to the methanol vaporization heat amount and the methanol decomposition heat amount, respectively. Therefore, methanol as fuel a is cracked using all the exhaust heat energy of 2 m of gas turbines, and a mixed gas consisting of (1,000,2 H2 CO) is supplied to the turbine system as a secondary fuel a'. The apparent heat generation welfare of methanol can be increased by (Δk(1+ΔHa)).As a result, the power generation efficiency of methanol, which was conventionally slightly disadvantageous compared to LNG vaporized gas, can be improved. It becomes possible to make it superior to LNG vaporized gas.

Incidentally, the methanol cracking and chemical reaction process described above require an appropriate catalyst, and for this catalyst, a conventionally known catalyst may be used. As a single unit, it is preferable to use, for example, the one previously introduced by the present applicant in Japanese Patent Application Laid-Open No. 57-68140.

Thus, according to this system where methanol is used as the total fuel a, the methanol is converted into a mixed gas of (CO + 2H2) by obtaining the necessary thermal energy from the exhaust heat gas of the gas turbine in the Kula-King reactor 7b. It is decomposed and the thermal energy is increased and it is released into the turbine system.
"I8. Therefore, gas turbine power generation -
+, 2, the turbine output e obtained increases. On the other hand, the amount of energy converted into steam energy in the steam turbine system 3 decreases, and the steam turbine output f decreases.
Overall, it is important to increase the turbine output1jJi1
It becomes u. In other words, even if the waste energy released into the atmosphere remains approximately the same, the combined power generation capacity of this system will increase.

Incidentally, if F is the bolt obtained by converting the amount of fertilizer input into heat value, and the input heat at the inlet of the gas turbine 2a is ttp, then in the original Sunam, F and P are equal. If the amount of In energy of the gas turbine 2& is Q, then the relationship F=P=L, +W 凰 10 Q holds true. In addition, the loss in the steam cycle is L
', steam turbine output W! Then, Q = L 2
Seven W2 There is a relationship. However, if the loss coefficient in the gas turbine 2a is 6g, the power generation efficiency is η8, and the power generation efficiency in the point air turbine 4a is η8, then Ll=εg−p Wl−η, −P Q =P・(1−j, -'7g) L2 '''P・(l−−−η3)・(1−η8)W,
==p ・(1=g−ηg) ・η8
Since it is shown as , the total power generation unit 1 A.
=wl+W.

=P·η, +P(1−ε8−ηg)·η8. For example, 6g-0,05, η, unit 1,295,
If given as η320.2, then W=0.
426P, and the total power generation efficiency η is η=W/FX100chi 42.6%.

On the other hand, according to this system, part of the exhaust heat energy R of the gas turbine 2a is recovered to increase the energy of the fuel a' at the input [] of the gas turbine 2&. It is given as R. And, at this time, each energy of is to L'm2・P′=ε,・()”+R)>L.

W′1=η,・P′=η□・(,P 10,R,)=w1
+η1·m>wl, and the loss L1 in the gas turbine 2a increases slightly, but the coupin output W'1 also increases. The inlet heat amount S in the steam cycle system is slightly smaller than the heat amount Q' in the conventional system, S = Q'-R=P'・(1-4g'g)-R=
(P+R)・(1−ηg−′g)−R・2P・(1−η
, -gg) -R(ηg+'g)=Q-a・(η, 10)
<Q. Also, here, 1,/, =S・(1−η,) w′,=s・η8 =W, −R・(η, +6g)・η3<W.

w'=%%/',+VV'*
□=w1+w2+η□・RouR(η1+6.ruη,・
Shown as □. , therefore, the overall generated energy J
This will result in an increase in i w/. And R=O
, 176
becomes. Therefore, if approximately 17.6% of the input ball energy is recycled, it is possible to improve the power generation efficiency by 4% out of Δη = (η'-η)xioo%, and the relative value In this case, δ=(
Limited! V)×1 o o% per month09.3%0.426P, and it is possible to improve the power generation efficiency by about 9.4%.

As explained above, according to this system, alcohol with a small number of carbon atoms, such as methanol, is used as fuel. - Even if the power generation efficiency is
Practical soil has great effects.

Note that the present invention is not limited to the above embodiments. For example, as e-material a, only methanol, ethanol,
Alcohol groups such as butanol and hydrocarbons such as fluoropane, butane, and naphtha can also be used. This system can be applied not only to power generation plants, but also to gas turbine main/engine systems for ships, and can also be widely used in general industrial I-turbine power units, etc. In short, the present invention can be modified and implemented without departing from its gist.

[Brief explanation of drawings]

Figures 1 to i, l (Figure 3 shows an example of a conventional system; Figure 1 is a block diagram showing a schematic configuration; 81!2
The figure is a system +lvJ diagram, and Figure 3 is a schematic diagram showing the relationship between energy and human output. Figures 4 to 7 show a system according to an embodiment of the present invention, and Figure WJ4 shows the system 11'4.
Figure 7 is a schematic diagram showing the relationship between energy and human output, and Figure 7 is a diagram showing a comparison of the amount of heat produced by combustion of fuel. '1...Combustor□, 2'...Gastar bin power generation system, 2a...Gas turbine, 2b...Generator, 3.
...1 no 1 heat 1''; Ira type, 3:a... flue, □3b
...Feed water preheater, 3'c...Steam generator, 4'...
・Steam turbine power generation system, 4a...Steam turbine, 4b
'-' Generator □Electric machine, '5... Water filter 1, 6... Cooling water bottle, 2:... Whale King reactor, □7 &...
Fuel preheater, 2b... Combustion: I carburetor. 1.

Claims (1)

[Claims] In a combined power generation system equipped with a steam turbine driven by a star pin and a steam turbine driven by the exhaust heat energy of the gas turbine, part or all of the fuel supplied to the gas turbine is converted into Some r
A fuel cracking combined power generation system characterized in that the fuel is chemically reacted with the fuel, converted into a secondary fuel with higher combustion energy than the fuel, and supplied to the gas turbine.