JPS6093132A - Gas turbine cycle - Google Patents

Abstract

PURPOSE:To promote the improvement of thermal efficiency, by using a mixed phase mixture, obtained by injecting liquid phase water into compressed air, as the intermediate cooling of a compressor and the preliminary cooling of compressed air. CONSTITUTION:The atmospheric air 3 sucked by a compressor AC1 is allowed to flow into an intermediate cooler IC from a pipe 4, and the air, after it is adiabatically compressed again by a compressor AC2, is delivered from a pipe 6. A part of the compressed air from the pipe 6, after it is compressed by an auxiliary compressor AC3, is divided to flow into pipes 11, 12 from a pipe 10, and liquid phase water from a pressurized water introducing pipe 2 is injected from pipes 13, 14 into the compressed air in the respective pipes 11, 12. In such way, a produced mixed phase mixture, after its heat is recovered by being introduced respectively into a self heat exchanger SR and the intermediate cooler IC, is introduced into a combustor CC through an intermediate temperature side heat recovery device R1 and a high temperature side heat recovery device R2. In this way, thermal efficiency of a gas turbine cycle can be improved 1.5% or more.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water injection gas turbine cycle, in which liquid phase water is injected into part or all of the compressed air obtained by compressing air or a gas mainly composed of air using a compressor. A method of recovering heat using a mixed mixture of compressed air/water/steam obtained by using a mixed mixture of compressed air/water/steam, characterized in that the multiphase mixture is only used for intermediate cooling of the compressor and cooling of the compressed air that is the raw material for forming the mixed mixture. In a preferred embodiment, it is a gas turbine cycle that can achieve a thermal efficiency of 49% or more (LHV standard) at a turbine inlet temperature of 1000C.

The present inventor has proposed that heat recovery from turbine exhaust gas or heat recovery from turbine exhaust gas and intermediate cooling of compressor can be achieved using a multiphase mixture of compressed air/water/steam obtained by injecting liquid phase water into part or all of the compressed air. In a gas turbine cycle that performs this process, it was discovered that a large thermal efficiency could be achieved by cooling the compressed air used to form the mixed U mixture with a portion of the multiphase mixture in advance. -19
No. 9363). The thermal efficiency according to this patent is 3-4% higher than that obtained with a combined gas turbine-steam turbine cycle under comparable operating conditions.

At the time Δ1:, the exhaust gas temperature was approximately 80C, which was an extremely low value.

After that, as a result of continuing to study the gas turbine cycle configuration for cases where the exhaust gas temperature cannot be lowered, such as the acid dew point of the exhaust gas or white smoke pollution, we found that the η11 of the present invention
<, Low wet side heat cycle 'L' of gas turbine exhaust gas! It has been found that even in a cycle without the addition of a vessel, the decrease in thermal efficiency can be suppressed to around 1.5% compared to 1) Patent No. 11.The thermal efficiency of this cycle is still 1.5% lower than that of the combined cycle.
．． Combined cycle 31 with waste gas at the same temperature as the present invention is more than 5% higher than 2.5% l-higher.

That is, the present invention compresses air or a gas mainly composed of air, which is used as a combustion-supporting gas, working medium gas, etc., using a compressor. A multiphase mixture of compressed air/water/steam obtained by injecting liquid phase water into part or all of the compressed air formed by the process is used for only intermediate cooling of the compressor and precooling of the compressed air used to form the miscible mixture. , a gas turbine cycle in which pressurized water is optionally used in combination with the multiphase mixture.

The multiphase mixture of the present invention does not necessarily mean that liquid phase water is dispersed in compressed air in an ideal state like mist or mist, and is conveyed and receives heat, but that water partially circulates within a heat exchanger. This includes practical aspects such as sequential injection and dispersion of liquid phase water within a heat exchanger.

An example of a flow sheet of the present invention will be explained below with reference to the accompanying drawings.

The drawing shows a turbine exhaust heat recovery device 3, an intercooler 1, a heat exchanger for cooling the raw material compressed air for forming an admixture (hereinafter referred to as a self-heat exchanger) 11, an air compressor 2, an auxiliary air compressor 11, and a turbine 1. This is the case. Atmospheric air (3) taken in by the air compressor (Act) is adiabatically compressed and enters the intercooler (IC) through the pipe (4). The intermediate stage compressed air (5) cooled by the intercooler (IC) is transferred to the air compressor (AC2)
Then it is adiabatically compressed again and discharged from the pipe (6). pipe (6)
A part of the compressed air from W(7) is transferred to the self-heat exchanger (
sR) and is further compressed by the auxiliary air compressor (AC3) through the pipe (9) to compensate for the pressure loss caused by the heat recovery equipment. ,skeleton(
11), (+21 each has a compressor intercooler (IC)
Pressurized water inlet pipe used as a heat recovery medium in the low temperature section of
The pressurized liquid phase water from 2) is injected through pipes (13) and (14) to form a miscible mixture, which is then sent to the self-heat exchanger (SFI) and intercooler (IC) through pipes (151 and (+6)), respectively. The remainder of the compressed air from pipe (6) is introduced into pipe (8).
The heat is introduced into the higher temperature side heat recovery unit (RI). In the self-heat exchanger (SR) and intercooler (IC), heat recovery is performed mainly through the latent heat when the liquid phase water in the mixed mixture undergoes a phase change to water vapor, and usually a saturated to slightly dry compressed air/steam mixture is recovered. The pipe (1η) is introduced into the medium-temperature side heat recovery unit (R2) via the country, and after the heat is recovered until the temperature reaches the same level as the compressed air from pipe (8), the heat from pipe (8) is Together with the compressed air, it is introduced into the high temperature side heat recovery device (R8) through the pipe (191J), where the heat is recovered and introduced into the combustor (cc) through the pipe (20).

Combustion n (CG) is equipped with a tube (
The fuel from 1) is added and becomes combustion gas at a predetermined temperature, which is introduced into the turbine (ET) through the 'PF (21). The combustion gas expands adiabatically, and the air compressor (Act), (
AC2) and load σ・) are generated, and the pipe (22
), and some of it is discharged from the fuel preheater (23) through the pipe (23).
R3)-, and the other is a heat recovery device (R1) on the higher temperature side than the pipe (24).
), then the heat is recovered through the medium temperature side heat recovery device (R2) and becomes low temperature waste gas (251).The air compressor (Act
), (AC2), the sealing air introduced into the turbine (ET), and the cooling air introduced into the turbine (ET) are of course required separately in the mechanical design.

Although an example of the outline of the 70-sheet of the present invention has been shown above with reference to the drawings, the present invention provides a method for converting a multiphase mixture of compressed air/water/steam into the compressed air used to form the multiphase mixture (if the temperature of the liquid water is high). (liquid phase water is also used) in advance as a part of the multiphase mixture and for intermediate cooling of the compressor, and as long as this operation is used, various modifications can be made. Examples include changing the location or not using pressurized liquid-phase water as a low-temperature heat recovery medium, using fuel as a refrigerant for intercooling, and reheat cycling. Even at high compression ratios, the rate of decrease in thermal efficiency is 31 times smaller than that of conventional gas turbine cycles, which is a great advantage when increasing specific output or implementing an ILT heat cycle.

The basic flow of the gas turbine cycle invented by Iku,
An example of its application is shown below, but from the point of view of operating conditions, the range in which the phase change conditions for the liquid phase water component to water vapor in the multiphase mixture can be more advantageously utilized is firstly the intermediate cooling of the compressor. Alternatively, the optimum required amount of compressed air m, which is the raw material of the multiphase mixture used for self-heat exchange, is determined from conditions such as the amount of heat exchange medium that can be realized with the heat medium of the multiphase mixture, but the thermal efficiency From the point of view, a necessary and sufficient total (minimum necessary if) is preferable. Also, regarding the meter for liquid phase water injected into the compressed air, we will select the most suitable option (■).

This preferred operating range depends on changes in the location or non-use of pressurized liquid-phase water as a low-temperature heat recovery medium, use of fuel as a refrigerant in intercooling, reheat cycle, or turbine inlet conditions. Of course things change. For example, in the flow sheet of the drawing, if the turbine inlet conditions are a pressure of 6 at and a temperature of 1000 C, the range in which the phase change conditions for the liquid phase water component to steam in the multiphase mixture can be more advantageously utilized is first The amount of compressed air that is the raw material for the multiphase mixture used for cooling or self-heat exchange is determined by the amount of heat exchange medium that can be achieved with the heat medium of the multiphase mixture, and the optimum required amount based on conditions such as the temperature difference. 30 mo1% or more of the total intake air amount]2, and from the standpoint of thermal efficiency, a necessary and sufficient amount (minimum required amount) is preferable. The amount of liquid phase water injected into compressed air is the total intake air 1
0.07-0.13 kymol per kymol. Preferably in the range 0.08-0.12 kgmol tT).

Furthermore, when intercooling is applied to a compressor, the pressure distribution before and after cooling should be determined from the viewpoint of increasing the compression power reduction effect due to intercooling.

In order to specifically show the effect of the present invention, Table 1 shows the effect of the present invention.
J example is shown. The conditions for each element used in the study are as shown in Table 2.

Table 1 Performance examples of the gas turbine cycle according to the present invention (
Note 1) In-house labor in the gas turbine auxiliary power pond was considered as 0.3% of the generated output.

(Note 2) The required amount of turbine cooling air was set considering that low temperature compressed air can be obtained in this cycle.

Table 2 Conditions for each element used in the calculations in Table 1

[Brief explanation of the drawing]

The drawing is a 70-sheet showing an example of the invention. (2) is added water introduction pipe, (3) is atmospheric air, (5) is intermediate stage compressed air, (61 (7) (8) f91 (In
) (12) (13) (141(15) (1
6) (17) (18) is a pipe, (R1) is a high temperature side heat recovery device, (R2) is a medium temperature side heat recovery device, (R3) is a heat recovery device,
(IC) is an intercooler, (SR) is a self-heat exchanger, (A
c1) (AC2) is the air compressor, (AC3) is the auxiliary air compressor, (CC) is the combustor, (ET) is the turbine,
The direction indicates the load. Patent applicant Mitsubishi Gas Chemical Co., Ltd. Patent applicant agent

Claims (1)

[Claims] 1) In a water-injected gas turbine cycle, a part or all of the compressed air obtained by compressing air or a gas mainly composed of air used as a combustion support gas, working medium gas, etc. by a compressor is added. A gas characterized in that the multiphase mixture of compressed air/water/steam obtained by injecting phase water is guided to intermediate cooling of the compressor and precooling of the compressed air used to form the multiphase mixture. turbine cycle. 2) The gas turbine cycle according to claim 1, characterized in that pressurized water is used in combination with the miscible mixture as required.