JPS59165828A - Gas expansion cooler for gas turbine - Google Patents

Abstract

PURPOSE:To cool gas of high temperature and high pressure by a small amount of water and sufficiently reduce a pressure of the gas simultaneously, by reducing the pressure of th gas through a porous plate orifice in a gas flow path in a cooler thereafter allowing the gas to flow in atomized cooling water so as to cool the gas. CONSTITUTION:A porous plate orifice 2 is provided in a gas expansion cooler, and cooling nozzles 4 atomizing cooling water are provided in the downstream of said orifice. Gas of high temperature and high pressure, being supplied from a gas feed port 1 and reducing its pressure by critical expansion through the porous plate orifice 2, is brought in contact with cooling water in a part of the cooling nozzle 4 and cooled by evaporation heat. In such way, the gas of high temperature and high pressure can be efficiently cooled reducing its pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a direct gas expansion cooler in a gas-fired gas turbine.

Conventionally, gas turbines that use gas as fuel have two methods: (1) In the case of an emergency shutdown, etc., there are two methods: (1) a method of dissipating high-pressure, high-temperature fuel gas into the atmosphere; (2) a method of burning it with a flare stack, etc.; c) There are methods such as providing a decompression device and a temperature reducing device and returning it to the system.

However, these methods have the following drawbacks.

(b) Method of dissipating into the atmosphere In the case of toxic gases, the area where they can be dissipated is limited from the perspective of air pollution, and consideration must be given to explosion protection and noise when dissipating, and measures should be taken to address these issues. Not only does it cost a lot of money, but it's also a huge loss of energy.

(b) Method of burning with a flare stack, etc.

In order to burn the gas emitted as a result of the dissipation, an emergency stop may occur at any time, so a torch burner, etc. must be used to prepare the receiver, which results in a large loss in fuel costs. . Furthermore, the current situation is that a highly reliable device is not available for urgently preparing the flare stack in response to an emergency stop. In addition, consideration must be given to noise, which is the same as above.

(c) A method with a pressure reducing device and a temperature reducing device and returning it into the system A turn (indirect water cooling type) is often used as a temperature reducing device, and when dissipating a large amount, the capacity of the turn becomes large and a large amount of water is circulated. must be kept on standby. This type of cooler requires handling as a pressure-resistant container, and there is also concern that performance may deteriorate due to corrosion and dirt on the cooler tube, making maintenance difficult. When using this cooler method, a closed type knoll pot is required for drain collection.

The purpose of the present invention is to solve the above-mentioned problems of the conventional system.It is possible to cool high-temperature, high-pressure gas with a small amount of water, and at the same time sufficiently reduce the pressure inside the system with a simple configuration. If it is possible to restore the fuel to the original condition, it will increase safety, reduce fuel energy loss, and have great benefits in terms of equipment costs and running costs.

The present invention compactly combines a pressure reduction function using a zeta-force pressure reduction porous plate orifice and a temperature reduction function using a direct water spray.

2) For emergency large-volume gas recovery, the latent heat of vaporization of water can be effectively activated, so only a small amount of cooling water is required.

(i) Since the depressurizing function part by the depressurizing porous plate orifice is covered with a part of the reduced-temperature water spray at approximately normal pressure, it is advantageous in terms of sound reduction (as a noise countermeasure).

2) Since the gas after being depressurized and sound-reduced is wrapped in the outer shell, the outer shell does not need to be used as a pressure vessel (no need for a pressure vessel body).

(3) Sprayed water for gas cooling is supplied via a head tank with the minimum required capacity for temperature reduction in the event of an emergency stop, so even if the cooling water pump should stop, the water will be removed as soon as the stop is detected. The gas turbine can be stopped safely and is extremely reliable.

This is a novel feature, and until now, there has never been anything that combines a pressure reducing function and a temperature reducing spray in this way.

The cooler of the present invention is a high-temperature, high-pressure gas body that can utilize the heat of vaporization from liquid spray, and is used in products that require pressure reduction, sound reduction, and temperature reduction, chemical process fields, and blast furnace gas-fired gas turbine fuel recovery. Applicable to devices.

Hereinafter, embodiments of the present invention will be described in detail with reference to accompanying drawings.

In the accompanying drawings, a high temperature, high pressure gas (not 100% saturated) is supplied from a gas supply port 1, introduced into a vacuum perforated plate orifice 2, and depressurized by critical expansion in the perforated plate orifice 2. The depressurized fuel gas is reversed in the upper part 3 of the system, passes through the band of cooling water (atomized spray) at the cooling nozzle 4, and comes into direct contact with water, causing the evaporation of minute water droplets. It is cooled by the heat of vaporization.

The fuel gas flows from the upper part 3 toward the cooling nozzle 4 while being cooled, hits overflow water, and is further turned toward the demister 6 at the lower part 5 of the diffuser 10.

The water that has not been completely evaporated is drained through the overflow pipe 7. After hitting the water surface and inverting the gas, the mist is further removed by the demister 6, and then the gas is recovered from the outlet 8 into another system stable.

The cooling water is supplied through the upper head tank 9. This head tank 9 has a minimum capacity for gas dissipation in an emergency.

To summarize the present invention, in a gas turbine that uses gas as fuel, in the event of an emergency shutdown, compressed high temperature, high pressure gas fuel is expanded and depressurized in a simple integrated structure, and the fuel is directly Sprayed water passes through a cooling section (direct cooler) that utilizes latent heat and sensible heat, and then circulates and recovers it to the supply main pipe. Conventionally, in such cases, one method was to release it into the atmosphere through a dissipation pipe. However, this includes pollution,
There are disadvantages such as danger, noise, and energy loss, but to alleviate these problems requires a large amount of equipment cost, other methods include pressure reduction devices using valves or orifices and shell-and-tube coolers ( There are indirect coolers), but these have disadvantages in terms of manufacturing costs and running costs, such as requiring a pressure-resistant container, reducing performance due to corrosion and dirt on the tubes, and requiring a large amount of cooling water. There was, but
This is a direct gas expansion cooler that eliminates or improves these drawbacks.

[Brief explanation of drawings]

The accompanying drawing is a sectional view showing a structure 7 of the cooler according to the present invention. 1. Gas supply 4. 2. Decompression porous plate orifice 3.
- Upper part of the chamber, 4. Cooling nozzle, 5. Lower part (diffuser), 6. Demister, 7. Overflow pipe.
8@・Exit, 9@・Head tank, 10・Diffuser.

Claims (1)

[Claims] A single or multiple perforated plate orifice is provided in the gas flow path in the cooler, and a cooling nozzle that sprays cooling water in the form of a mist is provided downstream of the gas flow path, and the pressure of the gas is reduced by critical expansion in the perforated plate orifice. A gas expansion cooler for a gas turbine, further characterized in that the gas is cooled through the spray cooling water.