JPH03258926A - Leveling method for gas turbine output - Google Patents

Abstract

PURPOSE:To prevent a reduction in gas turbine output due to the change in atmospheric temperature through a cheap equipment by driving an absorption refrigerating machine by a part of waste heat of an intercooler for a gas turbine, and cooling suction air of the gas turbine by the generated cold. CONSTITUTION:Suction air A' delivered from a low-pressure side compressor 6A is cooled by cooling water at the low-temperature section 9B of an intercooler 9, and the waste heat obtained by cooling suction air A at the high- temperature section 9A becomes a heat source of a singlet utility absorption refrigerating machine 12 through a hot water circulating pump 11. The cold water cooled in the absorption refrigerating machine 12 is sent to a heat exchanger 8 for the suction air A through a cold water pump 13 to cool the suction air A. Compressed air A'' cooled at the low-temperature section 9B of the intercooler 9 is sucked and pressurized as suction air for a high-pressure side compressor 6B, and the air delivered from there is supplied to a combustor 1, becomes high-temperature combustion gas together with fuel F, and the combustion gas is then guided to a gas turbine 3 to generate electricity through an electric generator 4.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a gas turbine that utilizes a portion of waste heat from an intercooler of the gas turbine to prevent a decrease in the output of the gas turbine when the temperature rises. This relates to an output leveling method.

[Conventional technology]

Conventional gas turbines have had the problem of significant changes in output due to changes in atmospheric temperature.

That is, in the winter when the atmospheric temperature is low, the air density is high, so the gas turbine output is sufficient, whereas in the summer when the atmospheric temperature is high, the output is reduced.

Conventionally, therefore, a method has been adopted to adjust the temperature of the gas turbine's intake air using a dual-effect absorption chiller operated by steam generated in a waste heat boiler that utilizes the heat of the gas turbine's exhaust gas. In this case, there were problems in that the equipment cost was high and the heat capacity was too sufficient to obtain the energy (cold heat) necessary for adjusting the intake air temperature.

On the other hand, in a gas turbine with an intercooler that has an intercooler between a low pressure compressor and a high pressure compressor that are directly connected to the turbine, the energy exchanged in the intercooler is discarded as hot water.

The inventors of the present invention focused on this point, and as a result of various studies,
It has been found that by using this discarded hot water as a heat source to cool the intake air of a gas turbine, it is possible to prevent a decrease in output due to a rise in temperature in the summer with inexpensive equipment, leading to the present invention.

[Problem to be solved by the invention]

An object of the present invention is to provide a gas turbine output leveling method that can prevent a decrease in gas turbine output due to atmospheric temperature changes using inexpensive equipment without significantly modifying a gas turbine equipped with an intercooler. .

[Means to solve the problem]

As a means for solving the above problems, the gas turbine output leveling method of the present invention uses part of the waste heat of the intercooler of the gas turbine to drive an absorption refrigerator using the waste heat as a heat source. The cold heat generated by the absorption refrigerator cools the intake air of the gas turbine, thereby preventing a decrease in the output of the gas turbine due to a rise in temperature.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

Fig. 1 is a system diagram of a cogeneration system to which the method of the present invention is applied, in which fuel F and compressed air supplied from pressure w3 generator 6 are mixed and combusted in combustor I, and the combustion gas is used to generate a generator. A gas turbine 3 that drives a turbine 2 directly connected to a gas turbine 4.
and a waste heat boiler 5 that generates gas S using the exhaust heat of the exhaust gas E of the turbine 2.

A compressor 6 is directly connected to the turbine 2, and the intake air A that has passed through the intake filter 7 is cooled by a heat exchanger 8 and then compressed by the low-pressure side compressor 6A. The compressed suction air A' is cooled in the high-temperature section 9A and low-temperature section 9B of the intercooler 9, and then passes through the high-pressure side compressor 6.
It is further pressurized by B and introduced into the combustor 1.

The low-temperature section 9B of the intercooler 9 is cooled by cooling water W, but the waste heat obtained by cooling the intake air A in the high-temperature section 9A is transferred to a single-effect absorption refrigeration system via a hot water circulation pump 11. It becomes a heat source for the machine 12.

Furthermore, the cold water cooled by the absorption refrigerator I2 is sent to the heat exchanger 8 for the suction air A by the cold water pump 13, and cools the suction air A.

That is, suction air A' discharged from the low-pressure side compressor 6A is cooled with cooling water W etc. in the intercooler 9, but a part of it is absorbed and frozen in the high temperature section 9A via the hot water circulation pump 11. It serves as a heat source for the compressor 12 and cools the compressed air A' of the low pressure side compressor 6A. Furthermore, the compressed air A' cooled to a predetermined temperature in the high-temperature section 9B is sucked in as suction air by the high-pressure side compressor 6B and pressurized, and the air discharged from there is supplied to the combustor 1, where it is supplied together with fuel F. The resulting high-temperature combustion gas is guided to the turbine 3 and generated by the generator 4.

Next, Figure 2 shows the above gas turbine 3 that responds to temperature changes.
Normally, as the temperature rises, the output No. at the reference point of the output of the gas turbine 3 at the reference temperature of 15 degrees Celsius decreases to the right as shown in the diagram Nx. When the output decreases, the output increases upward to the left, and it is possible to increase the output to the limit value N of the generator 4.

Accordingly, in the present invention, by cooling the intake air A when the reference temperature is 15° C. or higher, it becomes possible to maintain the output characteristics shown by the - dotted chain line Nc.

〔Effect of the invention〕

As explained above, according to the gas turbine output leveling method of the present invention, it is possible to prevent the output characteristics of the gas turbine from changing due to changes in temperature, and there is an advantage that a highly reliable cogeneration system can be provided. .

Further, in the present invention, the cooling waste heat from the intercooler, which was conventionally discarded as hot water, can be effectively used for cooling the intake air, so there is an advantage that the thermal efficiency of the entire system can be improved.

[Brief explanation of drawings]

FIG. 1 is a system diagram of a cogeneration system to which the method of the present invention is applied, and FIG. 2 is a diagram showing the relationship between the output of the gas turbine in FIG. 1 and the temperature of outside air. 3... Gas turbine, 6A... Low pressure side compressor, 8
... Heat exchanger, 9 ... Intercooler, 12 ... Absorption refrigerator, A ... Suction air.

Claims (1)

[Claims] Part of the waste heat from the intercooler of the gas turbine drives an absorption chiller that uses the waste heat as a heat source, and the cold energy generated by the absorption chiller cools the intake air of the gas turbine. A gas turbine output leveling method that prevents a decrease in turbine output.