JPS61171833A - Cooling system for gas turbine and generator - Google Patents

Abstract

PURPOSE:To permit the black start of a gas turbine by connecting a starting cooler and a cooler in parallel and connecting an emergency cooler on the downstream in series. CONSTITUTION:A starting cooler 1 and a cooler 2 are arranged in parallel, and an emergency cooler 3 is connected in series on the downstream. While, a cooling-water circulation pump 6 driven by a gas turbine through an auxiliary gear 11 and an emergency cooling-water pump 7 controlled by a cooling-water temperature controller 13 are connected in parallel. On starting, the cooling- water circulation pump 6 is driven to cool heat exchangers 8 and 9, and then the starting cooler 1 is started. When the outside air temperature is high, the emergency cooler 3 is started. Thus, the black start of the gas turbine is permitted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a cooling water supply system for a gas turbine and a generator, and in particular, in a gas turbine generator to which sealed cooling is applied, it is possible to improve the startup and stability of cooling water. This invention relates to a cooling water system for a gas turbine and generator that has been improved to provide superior water supply.

[Background of the invention]

As a gas turbine cooling water circulation system, for example, JP-A-53
As shown in Publication No. 65517, when a new heat exchanger is added to the cooling water system, in addition to the radiator that is cooled by the shaft-driven radiator fan of the gas turbine, a radiator equipped with a motor-driven radiator fan is installed separately. I was dealing with it. However, if the structure is such that a cooling water system is provided for the gas turbine alone, if the generator is a closed cooling type, a cooling system separate from the gas turbine cooling system must be installed. It is impossible to start without receiving an external power supply (hereinafter referred to as a black start), and if the gas turbine is installed indoors, it is extremely difficult to install a radiator inside the gas turbine package. (If you try to install it forcibly, it will cause the indoor temperature to overheat unless you provide a draft for cooling air intake or an exhaust chimney.)

The temperature of the cooling water supplied to the gas turbine generator lubricating oil cooler is not controlled, so if the outside temperature is low, the cooling water in the cooler will be quite low, so if a malfunction occurs in the temperature control valve, the gas Turbine generator lubricating oil becomes supercooled. If the temperature control valve operates normally, the above-mentioned overcooling can be avoided, but since overcooling of the lubricating oil can cause a serious accident, it is not preferable to rely solely on the temperature control valve.

Double and triple safety measures must be taken.

[Purpose of the invention]

An object of the present invention is to enable a black start (starting without using an external power source) in a gas turbine generator to which sealed cooling is applied, to provide an excellent stable supply of cooling water, and in particular to provide a gas turbine generator that does not rely solely on a temperature control valve. The cooling system for the gas turbine and generator shall be installed without the risk of overheating or overcooling of the generator lubricating oil.
Back [Summary of the Invention] First, the basic principle of the cooling system of the present invention created to achieve the above object will be explained as follows.

The conventional cooling water system consists of two systems: the gas turbine generator's lubricating oil cooling system and the generator stator cooling system. Driven through gears, the radiator fan was also driven by the turbine shaft, thereby cooling the cooling water. In addition, when using a separate radiator, instead of a turbine shaft-driven fan, a low-voltage startup motor-driven fan (starts to take the load from low rotation at the same time as the generator starts rotating, and starts the motor with low-voltage electricity. ) was installed to support black start. Lubricating oil cooling for gas turbine generators can enable a black start as described above, but a black start is difficult because the generator stator cooling system requires a separate cooling water circulation pump and radiator. .

Here, the present inventors paid attention to the following circumstances.

There is a difference between the maximum cooling water temperature required to cool the generator stator and the maximum cooling water temperature required to cool the gas turbine generator lubricating oil, with the former being approximately 50°C and the latter being approximately 60°C. There is. In other words, the lubricating oil can be sufficiently cooled even if the cooling water that has passed through the heat exchanger for cooling the stator of one generator is used in the heat exchanger for cooling the lubricating oil of the gas turbine generator.

Therefore, the inventors of the present invention connected the two systems in series, thereby making the amount of circulating water almost the same as when conventionally used for cooling lubricating oil. This solves the above-mentioned problem.

In order to achieve the above object based on the above principle, the cooling system for a gas turbine and a generator of the present invention cools a cooling medium by a cooling device, and pumps the cooled cooling medium to the gas turbine and the generator. In a cooling system that circulates through a generator, a plurality of cooling devices are connected in parallel via piping, a cooling device different from the above is connected in series downstream of the plurality of cooling devices, and the cooling medium is circulated. The pumping means for this purpose consists of a main pump that is constantly driven by a gas turbine via a gear transmission means, and an emergency auxiliary pump that is automatically operated when the outside temperature exceeds a predetermined value. characterized by something.

[Embodiments of the invention]

Next, an embodiment of the present invention will be described with reference to FIG.

The startup cooling device 1 and the cooling device 2 are connected in parallel, and the emergency cooling device 3 is connected in series on the downstream side thereof.

On the other hand, a cooling water circulation pump 6 driven by a gas turbine via an auxiliary gear 11 and a cooling water temperature control device 13
and an emergency cooling water pump 7 controlled by the system.

A temperature sensor portion of the cooling water temperature control device 13 is provided in the middle of the cooling water supply pipe 4 that connects the emergency cooling device 3 and the pump 6.7.

Next, the operation of the gas turbine and generator cooling system (FIG. 1) configured as described above will be explained.

First, the cooling water is supplied to the startup cooling device 1. It is cooled by the cooling bag w2 and the emergency cooling device 3, and the cooling water supply pipe 4. Cooling water circulation system through surge tank 5! 6 and an emergency cooling water circulation system 7 to a heat exchanger 8 for cooling the generator stator, and after being appropriately heated, it is supplied to a heat exchanger 9 for cooling the gas turbine generator lubricating oil.

At the time of starting the gas turbine, first, the cooling water circulation device 6 driven by the gas turbine shaft rotates the auxiliary gear 1 at the same time as the gas turbine starts.
1 to cool the generator stator cooling heat exchanger 8 and the gas turbine generator lubricating oil cooling heat exchanger 9. Electricity is supplied to the startup cooling device 1 (using a motor that can be started with low voltage) to start the device and cool the cooling water.

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Methods of driving the engine and performing a black start have already been implemented.

Furthermore, when the gas turbine generator reaches its rating, the cooling water temperature control device 13 detects the high temperature of the cooling water.

Start the cooling device 2.

When the outside temperature becomes high, the cooling water temperature required to cool the generator stator is approximately 50°C, and the startup cooling system and cooling system 2 cannot cool the cooling water to an appropriate temperature. Therefore, the emergency cooling device 3 connected in series on the downstream side is activated by a signal from the cooling water temperature control device 13 to improve cooling performance and adjust the cooling water temperature.

Furthermore, when the outside temperature rises, the difference in temperature between the inlet and outlet of heat exchange becomes smaller, so it is necessary to increase the amount of cooling water to satisfy the required amount of exchanged heat. Therefore, by starting the emergency cooling water circulation device 7 with a signal from the cooling water temperature control device 13, the cooling water temperature is adjusted.

Furthermore, in order to cope with rapid load fluctuations of the generator,
The generator output is measured and a signal from the generator load measuring device 10 is sent to the cooling water temperature control device 13, and the signal from the cooling water temperature control device 13 is corrected to control the cooling water temperature.

Further, when the outside temperature is low, the cooling water temperature control device 13 controls the emergency cooling device 3. In addition to controlling the cooling water supply temperature by operating or stopping the emergency cooling water circulation pump 7 and the cooling device 2, if the outside temperature drops further and the cooling water temperature becomes low, the cooling water supply temperature is A temperature controller 1 having a temperature control valve 14 provided at the heat exchange lI8 port and a temperature control valve 14 provided at the outlet of the heat exchanger 9 for cooling gas turbine generator lubricating oil.
Activated by a signal from 5, the cooling water is bypassed by the plumber 6
The outlet temperature of the gas turbine generator lubricating oil cooling heat exchanger 9 is controlled to be kept constant by sending it to the cooling water and returning it to the cooling water return pipe.

According to this embodiment, the gas turbine generator lubricating oil cooling heat exchanger 9 and the generator stator cooling heat exchanger 8 are connected in series, and the amount of circulating water is almost the same as that of the conventional one, so that the cooling water circulation device can be used as a cooling water circulating device. The cooling water circulation device 6 driven by the gas turbine shaft can be used, a black start of the gas turbine is possible, and the cooling system is shared between the gas turbine and the generator, so the total equipment cost can be reduced.

Cooling water temperature change device for changes in outside temperature! 13, the cooling device 2. and controls the operation of the emergency cooling system 3, it is possible to supply cooling water at a stable temperature as shown in Figure 2, and even when the outside temperature becomes high, the temperature difference between the inlet and outlet of the heat exchanger can be eliminated. Even if the water runs out, the emergency cooling water circulation system 7 can be activated to increase the amount of cooling water to satisfy the required amount of exchanged heat, allowing for smooth heat exchange and switching the number of operating devices according to the outside temperature, reducing power consumption. It is possible to operate with low cost and excellent economic efficiency.

Since the fluctuation in cooling water temperature due to changes in generator load is more rapid than the fluctuation in cooling water temperature due to fluctuation in outside air temperature, this load fluctuation is measured by the generator load measuring device 10 to control the cooling water temperature. This signal is sent to the device 13, corrects the signal from the cooling water temperature control device 13, and controls the operation of the equipment before the cooling water temperature fluctuates, thereby preventing sudden changes in the cooling water temperature due to sudden changes in the generator load. can.

A generator stator cooling heat exchanger 8 is provided upstream of the gas turbine generator lubricating oil cooling heat exchanger 9, and the gas turbine generator lubricating oil cooling heat exchanger is further provided by the temperature control valve 14 provided upstream. By controlling the outlet cooling water temperature of $9, the inlet temperature of the heat exchanger 9 can also be kept almost constant, so even when the outside temperature is low, the generator stator cooling heat exchanger 8
Since the cooling water that has been appropriately heated is supplied to the gas turbine generator lubricating oil cooling heat exchanger 9, overcooling of the lubricating oil can be prevented.

To explain this situation using Figure 3, even if the cooling water temperature drops due to extremely low outside temperatures or other troubles, the amount of water in the generator stator cooling heat exchanger 8 will be reduced. Since the cooling water passes through the heat exchanger 8, the temperature of the cooling water can be brought close to normal. Note that the temperature of the lubricating oil of the gas turbine and generator is controlled to be constant by controlling the outlet water temperature of the heat exchanger 9 for cooling the lubricating oil of the gas turbine generator.
[Effects of the Invention] According to the present invention, a black start is possible even in gas turbines and generators to which sealed cooling is applied, and temperature changes in the cooling system can be minimized even when the outside temperature and load change. I can do that.

Furthermore, since the temperature of the cooling water entering the lubricating oil cooling heat exchanger can be kept almost constant, it has the excellent practical effect of improving reliability during startup and operation of gas turbines and generators. play.

[Brief explanation of drawings]

Fig. 1 is a gas turbine and generator cooling water system diagram in one embodiment of the present invention, Fig. 2 is a graph of cooling water temperature changes with respect to outside air temperature changes, and Fig. 3 is a graph of cooling water temperature changes in one cooling cycle. It is. 1... Start-up cooling device, 2... Cooling device, 3...
Emergency cooling device, 4... Cooling water supply piping, 5... Surge tank, 6... Cooling water circulation pump, 7... Emergency cooling water circulation pump, 8... Generator stator cooling heat Exchanger, 9... Gas turbine generator lubricating oil cooling heat exchanger, 10... Generator load measuring device, 11... Auxiliary gear. 12... Cooling water return pipe, 13... Cooling water temperature control device, 14... Temperature control valve, 15... Temperature controller,
16...Bypass piping, 17...Gas turbine package. 18... Generator package.

Claims (1)

[Claims] 1. In a cooling system in which a cooling medium is cooled by a cooling device and the cooled cooling medium is pumped and circulated to a gas turbine and a generator, a plurality of cooling devices are piped in parallel. A cooling device different from the one described above is connected in series on the downstream side of the plurality of cooling devices, and the pressure feeding means for circulating the cooling medium is operated by a gas turbine in a steady state via a gear transmission means. A cooling system for a gas turbine and a generator, characterized in that it is equipped with a main pump that is driven automatically, and an emergency auxiliary pump that is automatically operated when the outside temperature exceeds a predetermined value. . 2. The above-mentioned cooling system includes a heat exchanger for cooling the generator stator on the upstream side, a heat exchanger for cooling the gas turbine generator lubricating oil on the immediate downstream side, and a heat exchanger for cooling the gas turbine generator stator. A means for detecting the temperature of the cooling medium at the outlet of the oil cooling heat exchanger, and a valve means whose switching is controlled by the signal output of the detection means are provided, and the temperature of the cooling medium flowing into the generator stator cooling heat exchanger is provided. The cooling medium temperature at the outlet of the gas turbine generator lubricating oil cooling heat exchanger is automatically controlled by bypassing a part of the cooling medium to the coolant outlet side of the gas turbine generator lubricating oil cooling heat exchanger. A cooling system for a gas turbine and a generator according to claim 1, characterized in that the cooling system is configured as follows. 3. Providing a temperature detection section of a cooling water temperature control device in a conduit connecting the cooling device and the equipment to be cooled, and inputting an output signal of the generator load measuring device to the cooling medium temperature control device; Claim 1, characterized in that the cooling medium temperature control device is configured to control the operation of the cooling device and the operation of the cooling medium circulation pump.
Cooling systems for gas turbines and generators described in Section 1.