JPH05164888A - Gas turbine power generating set - Google Patents

Abstract

PURPOSE:To enable a system to be safely operated with no plant suspended in operation even if seals fail at the boundary between a primary system and a secondary system or even if pipes are cracked, and also make the whole of a plant compact in a gas turbine power generating system using a high temperature gas-cooled reactor as a heat source. CONSTITUTION:A gas turbine 8 is a direct cycle turbine where helium is used as working medium for not only a primary system but also a secondary system, and two compressors 3 and 7 circulating helium through both the primary system and the secondary system are driven by the gas turbine 8 in the primary system. Furthermore, a turbine/compressor is supported by helium gas bearings 10. In addition, a cooler 6 in the secondary system is formed into a triple pipe structure, and buffer helium gas is sealed in the middle between helium gas and cooling water.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a direct cycle gas turbine power generator using a high temperature gas cooling furnace, a coal gasification furnace, sunlight or the like as a heat source.

[0002]

2. Description of the Related Art FIG. 3 is a flow diagram showing an example of a conventional gas turbine power generator using a high temperature gas cooling furnace as a heat source. The nuclear heat of the high temperature gas cooling furnace 01 is absorbed by helium gas and sent to the steam generator 02 via the blower 03.
Then, the water in the utilization system is heated to produce high temperature and high pressure steam. Using this steam, nuclear heat is converted into electric power by the output turbine 04 and the generator 05. Further, the steam discharged from the turbine after working is turned into water by the condenser 06 and returned to the steam generator 02 by the pump 07 again. In this way, water, which is the working medium in the secondary system, is circulated. On the other hand, a part of the circulating water is extracted from the outlet of the pump 07, the water turbine 08 is driven, and the blower 03 directly connected thereto is rotated to circulate the helium gas that is the cooling medium in the primary system. In addition, blower 03
A helium buffer gas seal device 09 is provided between the water turbine and the water wheel 08 to separate the helium gas as the primary cooling medium and the water as the secondary working medium.

[0003]

In the conventional gas turbine power generator, the boundary of the primary system using helium gas as the working medium and the secondary system using water / steam as the medium is the helium buffer gas sealing device 09 and the steam. There are two parts of the generator 02. In these boundaries, for example, the following failures (1) The control system of the helium buffer gas sealing device loses its function. (2) A crack occurs in the pipe of the steam generator. In the case of occurrence of water, the working medium of the secondary system leaks into the primary system, and the plant must be shut down to remove it. Not only does this lead to a decrease in plant availability, but if it reacts with the graphite material that makes up the core,
There is a risk that the plant itself cannot be restored.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned conventional problems, the present invention provides a helium gas discharged from a high temperature gas furnace for a primary system gas turbine, a high temperature side flow path of a heat exchanger, and the above primary system. A primary circulation system that returns to the high-temperature gas reactor through a primary-system compressor driven by a gas turbine in sequence, and a helium gas that is different from the helium gas that has exited the low-temperature side flow path of the heat exchanger, an output turbine, A secondary circulation system that returns to the low temperature side flow path through a cooler and a secondary compressor driven by the primary gas turbine in sequence, and the primary gas turbine and the primary compressor are helium. A gas turbine power generator characterized in that it is supported by a gas bearing; and, in addition to the above requirements, the cooler is constituted by a triple pipe with a buffer helium gas interposed between a working gas and cooling water. It proposes a gas turbine power generating apparatus characterized by the.

[0005]

As described above, the present invention provides a so-called direct cycle gas turbine system in which not only the primary system but also the secondary system uses helium gas as the working medium, and the working medium of the primary system and the secondary system is , Is circulated by a compressor driven by a primary gas turbine, and the turbine / compressor is supported by a helium gas bearing,
Problems of conventional plants, that is, leakage of oil or water from bearings or secondary systems are solved.

Further, the cooler in the secondary system has a triple pipe structure in which the buffer helium gas is interposed between the working helium gas and the cooling water, so that the core of the cooling water can be maintained even if cracks occur in the pipe. Direct leakage into the inside can be prevented.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a flow chart showing an embodiment of the present invention.

This embodiment comprises a primary system including the high temperature gas furnace 1 in which radioactive helium gas is circulated and a secondary system in which normal helium gas is circulated. Those boundaries are the buffer gas seal 9 and the heat exchanger 2.

The helium gas compressed by the primary compressor 3 is heated in the high temperature gas furnace 1 to obtain high enthalpy. Then, the gas is sent to the gas turbine 8,
Therefore I work by the enthalpy head. HTGR 1
Then, high temperature and high pressure helium gas (750-850 ° C,
60-80ata) is used as the working medium. Also,
The design pressure ratio of the gas turbine 8 is 2-3. As a result, the gas temperature at the outlet of the gas turbine 8 is 400 to 500 ° C.
Becomes

The hot exhaust gas leaving the gas turbine 8 is
Entering the heat exchanger 2, the secondary system helium gas is heated.
Transfers heat to low temperature and low pressure (200 to 250 ℃, 20 to 20
The primary system helium gas which has become 30ata) circulates and returns to the primary system compressor 3 and is pressurized again to make one cycle of the cycle. The turbine 8 is directly connected to the primary compressor 3 and the secondary compressor 7, so that the work of the turbine 8 is used for boosting the helium gas in these compressors 3, 7.

The helium gas compressed by the secondary compressor 7 enters the heat exchanger 2 and, as described above, is heated by the primary system gas turbine outlet high temperature gas (400 to 500 ° C.) to be in a high enthalpy state. Become. After that, the work is performed by the output turbine 4, and the energy is converted into electric power by the generator 5 directly connected to the output turbine 4. Since the low-pressure exhaust gas that has finished its work in the output turbine 5 has a temperature of 200 to 250 ° C., it is further sent to the cooler 6 and cooled to near room temperature by cooling water, and then returned to the compressor 7 again to circulate the cycle. To do.

A buffer gas seal device 9 is provided between the gas turbine 8 in the primary system and the compressor 7 in the secondary system to separate the two. That is, radioactive primary helium gas and normal secondary helium gas are mixed in this part, but this mixed gas is sent to a helium gas purification facility (not shown) to make clean helium gum, and then the original helium gas is reused. By returning to the system, the helium gas of the secondary system can be always maintained as a working gas having no radioactive.

The turbine / compressor rotor is supported by a gas bearing 10 using helium gas as a lubricant. In case of small size, dynamic pressure gas bearing (contact pressure is 0.2 kg / cm ² or less),
In the case of a large size, a static pressure gas bearing in which a part of the helium gas boosted by the compressor 3 is supplied is adopted.

FIG. 2 is a transverse sectional view of a heat transfer tube which constitutes the cooler 6. This heat transfer tube is composed of three concentric pipes 61,
It is formed of 62 and 63. The high temperature secondary helium gas flows inside the inner pipe 61, and the cooling water passes through the annular cross section surrounded by the middle pipe 62 and the outer pipe 63. Buffer helium gas is enclosed in an annular cross section surrounded by the inner pipe 61 and the intermediate pipe 62. Therefore, in the unlikely event that the inner pipe 6
Even if the one or the middle pipe 62 is cracked, the cooling water only enters the buffer gas, and the leakage of the cooling water into the secondary helium gas can be avoided.

[0015]

EFFECTS OF THE INVENTION According to the present invention, a high-temperature gas-cooled furnace having a high efficiency and a high safety can be used. Further, since the direct cycle gas turbine is used, the entire plant can be made compact, which is economically advantageous.

[Brief description of drawings]

FIG. 1 is a flow diagram of a direct cycle gas turbine power generator according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a heat transfer tube which constitutes the cooler 6 in FIG.

FIG. 3 is a flow diagram showing an example of a conventional gas turbine power generator using a high temperature gas cooling furnace as a heat source.

[Explanation of symbols]

 1 High Temperature Gas Furnace 2 Heat Exchanger 3 Primary System Compressor 4 Output Turbine 5 Generator 6 Cooler 7 Secondary System Compressor 8 Primary System Gas Turbine 9 Buffer Gas Seal System 10 Gas Bearing

Claims (2)

[Claims] 1. The helium gas discharged from the high temperature gas furnace is sequentially passed through a primary system gas turbine, a high temperature side flow path of a heat exchanger, and a primary system compressor driven by the primary system gas turbine, and then the high temperature gas. The primary circulation system that returns to the furnace, and the helium gas that has flowed out of the low temperature side flow path of the heat exchanger and is different from the above helium gas, are sequentially output to the output turbine, the cooler, and the secondary compressor driven by the primary gas turbine. A secondary circulation system that returns to the low temperature side flow path via the above, wherein the primary gas turbine and the primary compressor are supported by helium gas bearings. 2. The gas turbine power generator according to claim 1, wherein the cooler is constituted by a triple pipe with a buffer helium gas interposed between a working gas and cooling water.