JPS6327525B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for cleaning the interior of a casing of a geothermal turbine that is operated using geothermal steam obtained from a steam well as a working fluid.

Geothermal steam, which is the working fluid of the geothermal turbine, is ejected from deep underground, and contains various impurities, such as mud, and corrosive components dissolved in hot water. Of this, most of the hot water is separated and removed by a steam-water separator before the turbine is introduced.
Still, some of it enters the turbines, along with mud and other solids from the earth's crust. Also, impurities contained in the steam, primarily silica, cause scaling problems. In particular, scale deposited on the blade surface narrows the steam passage area and causes a reduction in output. These problems are unique to geothermal turbines and are not found in ordinary thermal turbine plants.

This invention was made in response to the above-mentioned problems, and is a novel and unprecedented cleaning method that can clean and discharge mud and corrosive components accumulated inside the cabin and remove scale without disassembling the turbine. Our goal is to provide the following.

According to the present invention, the present invention is equipped with a cleaning hot water supply line and a drain drainage line that are connected to the turbine casing. , Washing hot water is injected into the turbine casing to a predetermined level through the washing hot water supply line, and the turbine rotor is driven to rotate by a turning device to clean the inside of the casing and the turbine rotor and remove precipitated scale, and then drain. This is achieved by discharging the cleaning waste liquid to the outside through a drainage line.

The method of the present invention will be explained below based on the illustrated embodiments.

The figure shows a system diagram for carrying out the cleaning method of the present invention. In the figure, 1 is a geothermal turbine, 2 is a condenser connected to its exhaust side,
The turbine 1 is operated by introducing geothermal steam from a steam well through the main steam supply line 3. Further, as is well known, the turbine 1 is composed of a casing 4, a turbine rotor 5, a gland packing 6 for shaft sealing, a drain pipe 7 drawn out from the casing 4 for each stage, and one end of the axle. A turning device 8 is connected to. Further, the turbine casing 4 and the condenser 2 are connected to each other via a bellows 9. According to the present invention, such a turbine is equipped with a cleaning hot water supply line 10 and a drain drainage line 20, and each line 1 is installed during cleaning.
0 and 20 are connected to the turbine 1 by piping. Of these, the cleaning hot water supply line 10 has a water tank 11 connected to a water supply source, a water supply heater 12, a liquid feed pump 13, and a hot water supply valve 14, and is connected to, for example, a flange of an internal inspection window of the passenger compartment 4. be done. On the other hand, the drain line 20 is installed between the drain pipe 7 and the drain pit 21 on the vehicle interior side, and a drain valve 22 is inserted in the line. Further, a branch hot water supply line 15 is drawn out from the middle of the hot water supply line 10, and a connector 2 attached to the tip of the drain drainage line 20 is attached to the tip of the branch hot water supply line 15.
3. Note that 17 is a hot water supply valve inserted in the branch hot water supply line 15. In addition, the gland packing 6 of turbine 1
A compressed air supply line 30 is connected from a compressor 31 through an air supply valve 32.

Next, a method for cleaning the turbine 1 will be described. During regular inspections or other necessary times, the dirt inside the turbine is visually observed using a borescope, etc., and if it is determined that cleaning is necessary, the turbine will be cleaned in the following order. . That is, first, the supply of main steam is stopped and the operation of the turbine 1 is stopped, and the internal temperature of the turbine is reduced to approximately
Natural cooling is performed over time until the temperature drops to around 100℃. Next, the cleaning hot water supply line 10 mentioned above,
In addition to connecting the drain drainage line 20 and the compressed air supply line 30, on the other hand, in order to protect the bellows 9 on the condenser side, the inside of the condenser body is heated to 50°C, which is approximately the same temperature as the turbine during normal operation. Fill with warm water. Note that the drain valve of the condenser 2 and the drain valves 22 of the drain drainage line 20 are all closed. Furthermore, compressed air supply line 30
Compressed air is supplied to the gland packing 6 under pressure. In this state, next, hot water heated to about 90°C is started to be poured into the passenger compartment 4 through the hot water supply line 10,
The hot water is stored up to approximately half the height of the interior of the vehicle interior, as indicated by H in the figure, and the turning device 8 is started to rotate the turbine rotor 5. As a result, the hot water for washing injected into the vehicle interior is stirred. Then, mud, dirt, and other corrosive components adhering to the inside of the vehicle and the turbine rotor are cleaned, and scale is removed. In addition, Grand Packkin 6
Since compressed air is pressurized from the outside, hot water will not leak outward through the gland packing. After this washing operation has been carried out for a predetermined period of time, for example, about 60 minutes, the drain valve 22 of the drain line 20 is opened, and the washing water in the vehicle interior is drained through the drain line 20 to the drain pit 21, and mud, dirt, etc. Allow scale, etc. to flow out of the turbine. Also, by connecting the branch hot water supply line 15 and the drain drain line 20 to each other via the connectors 16 and 23, and supplying hot water in reverse to the drain drain line 20 through the branch hot water supply line 15, the drain pipe 7 and the drain drain line 15 can be connected. Clean pipes and prevent pipe clogging. The progress of the above cleaning operation can be checked by visually inspecting the interior with a borescope through the flange of the inspection window that supplies hot water to the passenger compartment 4, checking for any abnormalities and the degree of cleaning, and checking for water flowing out from the drain line. Judge by looking at the cloudiness of the washing water. If it is determined that the cleaning has been completed sufficiently, then, with the hot water supply stopped, the cleaning water is completely drained from the passenger compartment through the drain line 20, and the inside of the condenser 2 is drained. Afterwards, the piping of each line 10, 20, and 30 is removed, and the blind covers are restored at the necessary locations to prepare for restarting the turbine operation. Furthermore, turbine 1
In addition to draining the interior of the vehicle, it is a good idea to actively dry it to prevent rust. Furthermore, while rotating the turbine rotor by hand turning, we visually inspected the inside using a borescope.
After confirming that there are no abnormalities, restart the turbine using main steam.

According to the above-mentioned cleaning method of the present invention, cleaning hot water is injected from the outside, and the interior of the vehicle can be cleaned and scale removed while rotating the turbine rotor using a turning device, and the turbine can be disassembled. It is possible to effectively clean the turbine without any cleaning, and its practical effects are extremely large.

[Brief explanation of the drawing]

The figure is a cleaning system diagram showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Turbine, 2... Condenser, 3... Main steam supply line, 4... Car compartment, 5... Turbine rotor, 6... Grand packing, 7... Drain pipe, 8... Turning device, 10...Cleaning hot water supply line, 20...Drain drainage line, 30...
Compressed air supply line.

Claims (1)

[Claims] 1. A cleaning hot water supply line and a drain drainage line are provided to be connected to the turbine casing, and when the turbine is not operating during cleaning, cleaning hot water is supplied into the turbine casing to a predetermined level through the cleaning hot water supply line, The turbine rotor is rotated by a turning device to clean the inside of the casing and the turbine rotor and remove deposited scale.
In the geothermal turbine cleaning method in which the cleaning waste liquid is then discharged through the drain drainage line, pressurized air is supplied from the outside to the gland packing part of the turbine during cleaning to prevent leakage of the cleaning waste water from the gland packing part. , the inside of the condenser connected to the latter stage of the turbine is filled with hot water that is almost the same as in normal operation, and when cleaning is completed, the cleaning wastewater is first drained through the drain drainage line, and then the A method for cleaning a geothermal turbine, characterized in that a cleaning hot water supply line is connected, cleaning hot water is made to flow back into the drain drainage line for cleaning, and then hot water in the condenser body is discharged.