JPH0681905B2 - Gas turbine power generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial field of application) The present invention relates to a gas turbine power generator using liquefied propane gas (hereinafter referred to as LPG), which is an electrical component / meter installed in an explosion-proof compartment. The present invention relates to a gas turbine power generator that can efficiently cool components.

(Prior Art) Conventionally, liquid fuels such as light oil and kerosene have been used as fuels for gas turbines, but recently, from the viewpoint of diversifying utilization of energy resources, gas such as liquefied natural gas (LNG) and LPG is used. Fuel is becoming heavily used.

The operation mode of the gas turbine includes liquid fuel exclusive combustion, liquid fuel / gas fuel mixed combustion, gas fuel exclusive combustion, etc.
Various operating modes have been adopted to reflect the energy situation of each region and each power plant. Among them, the gas-fuel exclusive combustion gas turbine increases the fuel gas transportation technology and increases the consumption ratio of gas fuel. In recent years, it has been on an increasing trend reflecting the policies of energy consumption plans that seek to balance various energy consumption ratios.

Furthermore, even in the same gas turbine power plant,
In recent years, it has become more and more common to operate a power generation plant using a plurality of types of gaseous fuels such as LNG and LPG or a mixed fuel thereof to provide a stable power supply.

Figure 4 shows the schematic configuration of the LPG / LNG dual-use gas turbine power plant. In the figure, the compressor 1, the gas turbine 2 and the generator 3 are coaxially directly connected,
The air compressed by the compressor 1 is supplied through the gas fuel strainer 4, the gas fuel stop valve 5, and the gas fuel control valve 6 to the LP.
G, or gas fuel strainer 7, gas fuel stop valve 8,
Combustor 10 with LNG supplied through gas fuel control valve 9
After mixing, the gas fuel is burned to drive the gas turbine 2 and rotate the generator. In the figure, 5a and 6a are valve opening transmitters attached to the gas fuel stop valve 5 and the gas fuel control valve 6, respectively.

Since LPG has a high dew point, it is easily liquefied, and particularly when operating a power plant, LPG is used at a pressure of 10 and several kg / cm ² g or more, so it becomes even easier to liquefy.

If this LPG causes liquefaction condensation in the fuel piping system, it may erode the fuel valve or cause uneven distribution of flow rate in the combustor, causing local abnormal high temperature of combustion gas. There is. Therefore, in any driving condition
To prevent liquefaction and condensation of NPG, electric heaters (not shown) and steam trace piping are installed in equipment such as the LPG piping system and fuel valves.
11 is installed by tying or winding to warm the pipes and valves to keep the gas fuel in the overheated area. Since LNG has a low dew point and is difficult to liquefy and condense, no electric heater steam trace pipe is installed in the LNG system.

Further, in order to prevent the fuel gas on the use side from entering the unused gas fuel system through the combustor 10, the downstream valves of the gas fuel control valves 6 and 9 and the valve opening transmitter 6a. Are connected to each other by air purge pipes 14 and 15 equipped with stop valves 14a and 15a, and the discharge air of the compressor 1 is connected to the unused gas fuel control valve 6,
It is led to the downstream side of 9 and the air purge between the gas fuel control valves 6 and 9 and the combustor 10 is performed.

By the way, among the equipment installed in the gas fuel system, the gas fuel strainers 4, 7, the gas fuel stop valves 5, 8, and the gas fuel control valves 6, 9 have a flange portion and a gland seal portion of the valve rod. Equipment is prone to wear such as gaskets and valve gland seals, and deterioration over time, but even if explosive gas leaks from these seals into the gas turbine building, the range of gas leakage is minimized. The above-mentioned equipment is housed in an explosion-proof compartment in order to keep the explosive gas safely released into the atmosphere.

Fig. 5 shows a concrete example of this. The gas fuel strainer 4, the gas fuel stop valve 5, and the gas fuel control valve 6 of the LPG gas fuel system are installed in the explosion-proof compartment 12 (hereinafter referred to as the explosion-proof zone). There is. In addition, a ventilation blower 16 is installed in the explosion-proof area to ensure that the leaked gas is released into the atmosphere in the event of a gas leak from equipment, and the ventilation in the explosion-proof area is always performed. . Further, in order to prevent explosive gas from leaking from the explosion-proof area into the gas turbine building, the inside of the explosion-proof compartment 12 is kept at a negative pressure with respect to the atmospheric pressure. The outside air is introduced via the.

(Problems to be Solved by the Invention) As described above, the steam trace pipe 11 and the air purge pipe 14 pass through the explosion-proof compartment 12, but these pipes are generally 100 The gas turbine 2
While operating with LNG fuel (the LPG system is not operating), the temperature inside the explosion-proof compartment 12 rises due to heat radiation or electric heat from the air purge piping system. In particular, the steam for steam tracing and the air for air purging can be continuously flowed during operation with LPG fuel and at rest, so the temperature inside the explosion-proof compartment becomes extremely high, and in the worst case, it is almost the same as those heat sources. The temperature may be about the same.

When the temperature inside the explosion-proof compartment rises, the temperature of electric / instrumentation equipment such as electric motors, valve opening transmitters, solenoid valves, pressure switches, etc. installed there also rises. Explosion-proof products are used as electrical products and instrumentation products used in explosion-proof compartments, but these explosion-proof products have insufficient heat resistance compared to general electrical products and instrumentation products.

Therefore, if these electric parts and instrumentation are used for a long time in a high temperature explosion-proof compartment, they may cause seizure and burnout in electric parts such as electric motors and solenoid valves, and valve opening transmitters and Problems such as malfunction and generation of erroneous signals are likely to occur in instrumentation equipment such as pressure transmitters.

In particular, valve opening transmitters and pressure transmitters are important devices that control the speed / load of gas turbines, but if these devices malfunction or generate false signals, the gas turbine may become uncontrollable. However, in the worst case, the gas turbine may be brought into an emergency stop or an acceleration state.

Therefore, the object of the present invention is to eliminate the above-mentioned drawbacks in the background art, and to prevent the high temperature in the explosion-proof compartment by providing an appropriate cooling means to the electrical components and instrumentation equipment installed in the explosion-proof zone. An object of the present invention is to provide a gas turbine power generator in which malfunctions and deteriorations of electric appliances and instrumentation based on the above are reduced.

[Structure of Invention]

(Means for Solving the Problems) In order to achieve the above-mentioned object, the gas turbine power generator of the present invention is a gas turbine power plant in which a gas fuel system and electric / instrumentation components are housed in an explosion-proof compartment. The instrument room in the explosion-proof compartment and the air in this instrument room
It is characterized in that a bypass pipe for feeding in the vicinity of the instrument is installed, and a bypass valve is provided at the instrument chamber discharge port.

(Operation) In the gas turbine power generator of the present invention configured as described above, low-temperature outside air is blown to the electric components / instrumentation components installed in the explosion-proof zone, so that temperature rise of them is prevented and safety is improved. In addition, the gas turbine power plant can be operated reliably.

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

In FIG. 1, an instrument chamber 20 is formed in one part of the explosion-proof compartment 12 by sharing the intake hole 17. This instrument room is constructed by using a heat insulating plate in order to reduce the radiant heat from the inside of the explosion-proof compartment, the inlet side damper 21 is provided at the inlet, and the outlet side damper 22 is provided in the middle. These dampers open when air flows into the explosion-proof compartment and close when air flows in the opposite direction to function as check valves.

The rear end of the instrument room 20 opens into the explosion-proof compartment 12 through the instrument room discharge port, and a bypass pipe is located below the opening end.
24 upper ends are connected. This bypass pipe 24 is an intake hole
The outside air sucked from 17 is sent to the vicinity of the electrical components / instrumentation equipment in the explosion-proof compartment 12, and the electrical equipment / instrumentation components (in this example, the gas fuel stop valve 5 and It opens in the vicinity of the valve opening transmitters 5a, 6a attached to the gas fuel control valve 6 and the thermocouples 5b, 6b) for temperature measurement. Further, a bypass valve 25 composed of a butterfly valve is provided at the upper end of the bypass pipe 24.
Is rotatably attached, and the flow rate of air flowing into the explosion-proof compartment 12 from the instrument chamber discharge port 23 according to the opening degree,
The proportion of the flow rate of air blown from the instrument room 20 through the bypass pipe 24 to the vicinity of electrical and instrumental components is adjusted.

FIG. 2 shows an example of the control circuit according to the present invention.
9A shows an example of a ventilation blower control circuit, and FIG. 9B shows a starting circuit of the bypass valve 25.

In FIG. 2 (A), a signal 31 indicating that the temperature inside the compartment is equal to or higher than a set temperature and a gas turbine start signal 32 are generated by the thermostat 30 installed in the explosion-proof compartment.
The signal is input to the OR circuit 33, and the activation signal 34 of the ventilation blower is output when these signal OR conditions are satisfied.

Further, FIG. 2 (B) shows a temperature signal in the instrument room measured by a thermometer (not shown) such as a thermocouple installed in the instrument room.
Is led to an adder 37 together with a signal 36 from a thermometer (5b, 6b, etc. in Fig. 1) installed on the surface of the electric / instrumentation equipment in the explosion-proof area, and their deviation signal 38 is generated by a pulse generator 39. To generate a bypass valve opening / closing signal 40.

Here, the pulse generator 39 gives a pulse in the closing direction to the bypass valve when the signal from the adder 37 is +, that is, when the temperature inside the instrument room is higher than the surface temperature of the electrical / instrumentation equipment, and in the opposite case. Is given a pulse in the opening direction to the bypass valve. Therefore, when the temperature inside the instrument chamber becomes equal to the surface temperature of the electrical component / instrumentation component, the pulse transmission from the pulse generator 39 is stopped and the opening degree of the bypass valve is fixed.

As described above, according to the present invention, the airflow that flows into the explosion-proof compartment flows from the explosion-proof compartment outside → the instrument room → the explosion-proof compartment through the damper provided at the entrance of the instrument room, and the instrument room has a heat insulating structure. Therefore, even if the temperature is high or low, the order of the air flow will be outside the explosion-proof compartment <instrument room <explosion-proof compartment, but the electrical components and instrumentation such as the valve opening transmitter installed in the explosion-proof compartment are Since the cool air in the instrument room is blown directly through the bypass pipe, the electrical and instrument components are kept below the maximum allowable temperature.

Further, in the case of this embodiment, since the ventilation air amount flowing through the bypass valve is distributed so that the temperature inside the instrument room and the surface temperature of the electric parts and instrument parts in the explosion-proof area become the same temperature, The capacity of the blower is maximized, and stagnation of ventilation air in the explosion-proof compartment is prevented.

FIG. 3 shows another embodiment of the present invention, in which the slide valve 50 is used as the bypass valve instead of the butterfly valve described above. In this case as well, the slide amount of the slide valve 50 should be adjusted. Directly through the bypass pipe 24
The flow rate of air blown to the instrumentation and the like and the flow rate of air supplied into the explosion-proof compartment 12 without passing through the bypass pipe 24 can be controlled to appropriate values.

〔The invention's effect〕

As described above, according to the present invention, since the cooling atmosphere can be directly sent to the vicinity of the electric / instrumentation equipment installed in the high temperature explosion-proof compartment, it is installed in the explosion-proof area. It is possible to prevent heat deterioration and malfunction of electrical parts and instrumentation parts, and to operate the plant safely and reliably.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of an explosion-proof compartment in the gas turbine power generator of the present invention, and FIGS. 2 (A) and 2 (B).
Is a circuit diagram showing an embodiment of a control circuit used in the present invention, FIG. 3 is a schematic diagram showing another embodiment of the present invention, and FIG.
FIG. 5 is a system diagram showing a schematic configuration of a gas turbine power plant, and FIG. 5 is a schematic diagram explaining a conventional ventilation method. 1 ... Compressor, 2 ... Gas turbine, 3 ... Generator, 4,7 ... Gas fuel strainer, 5,8 ... Gas fuel stop valve, 6,9 ... Gas fuel control valve, 10 ... Fuel device, 11 ... Steam trace Piping, 12 ... Explosion-proof compartment, 14, 15 ... Air purge piping, 16 ... Ventilation blower, 17 ... Intake hole, 20 ... Instrument room, 16 ... Ventilation damper, 22 ...
Exit side damper, 23 ... Instrument room discharge port, 24 ... Bypass pipe, 25
Bypass valve, 36 ... Thermostat, 37 ... Adder, 38 ...
Deviation signal, 39 ... Pulse generator, 40 ... Bypass valve open / close signal, 50 ... Slide valve.

Claims (4)

[Claims] 1. In a gas turbine power plant in which a gas fuel system and electrical components / instrumentation are housed in an explosion-proof compartment, an instrument room is provided in the explosion-proof compartment, and air in the instrument room is supplied to the electrical / instrumentation equipment. Install a bypass pipe to feed near the
A gas turbine power generator, wherein a bypass valve is provided at the discharge port of the instrument room. 2. The gas turbine power generator according to claim 1, wherein the bypass valve is a butterfly valve. 3. The gas turbine power generator according to claim 1, wherein the bypass valve is a slide valve. 4. An inlet-side damper and an outlet-side damper that function as a check valve are installed in the middle of the inlet of the instrument room, and the damper is provided in any one of claims 1 to 3. The described gas turbine power generator.