System and method for adjusting temperature of pure water system in shutdown state of giant internal water cooling generator set

Abstract

The invention belongs to the technical field of water wheel generator pure water temperature adjustment, and particularly provides a system and method for adjusting the temperature of a pure water system in the shutdown state of a giant internal water cooling generator set. The connecting position of the leaked water collecting mechanism and the technical water supply main pipe is arranged on the downstream of the technical water supply main valve, an electric valve is arranged on the leaked water collecting mechanism, and the leaked water collecting mechanism is connected with a secondary water inlet pipe of a pure water cooler of the pure water system to conduct secondary cooling on the pure water cooler. According to the system and the method, the temperature of the pure water system in the shutdown state of the unit is maintained in a constant-temperature state, and the influence of the temperature on the liquid level of the pure water system is eliminated, so that whether the pure water system leaks or not is accurately monitored.

Description

Technical Field

[0001] The invention belongs to the technical field of pure water temperature regulation of hydraulic generators, and in particular relates to a pure water system temperature regulation system and method for a giant water-cooled generator set in a shutdown state. Background Art

[0002] For large water-cooled turbine generator sets, the generator set is equipped with a generator pure water system, which cools the generator stator bars through the circulation cooling of the closed pure water system. The pure water system should remain in operation regardless of whether the unit is turned on or off. Each unit's pure water system involves thousands of joints or seals. If there is water leakage at these locations, it will cause a short circuit or tripping inside the generator. Therefore, it is very important to sensitively monitor the sealing conditions of these connection parts.

[0003] In order to prevent condensation when the generator set is shut down, a pit heater is arranged at the bottom of the generator. After the unit is shut down, the technical water supply valve used for unit cooling during the operation of the unit is too large and difficult to close completely, resulting in water leakage.

[0004] Regarding monitoring the leakage of the pure water system, the expansion water tank of the pure water system monitors whether there is leakage in the pure water system by comparing the difference between temperature and liquid level. The existing pure water system leakage monitoring method has too many false alarms due to the process of pure water temperature change and the influence of the water pressure of the expansion water tank on the float. Especially in the shutdown state, due to the leakage of the technical water supply of each unit, the water temperature of each part is actually inconsistent; because the unit is not running, the heat generated inside the generator is limited, resulting in limited regulation of the three-way valve of the pure water system; when passing through the pure water cooler, the water temperature is low due to the secondary cooling effect of the technical water supply leakage on the pure water system. When passing through the generator, due to the effect of the pit heater at the bottom of the pit, the water temperature is high, and it is impossible to lower the water temperature to 38 degrees Celsius in the shutdown state, resulting in inaccurate measurement.

[0005] At present, the pit heater is controlled by measuring the temperature in the pit. After the unit is shut down, the pit heater is automatically turned on and off when the pit temperature is lower than 40 degrees Celsius, and automatically turned off when it is higher than 45 degrees Celsius. The existing pit heater temperature is completely controlled by the air temperature, and there is water leakage in the technical water supply of each unit. When the unit is shut down, the technical water supply cooling water leaked from the inside of the generator stator wire rod is used to cool the pure water inside the generator for secondary cooling, resulting in a decrease in the internal temperature of the generator, while the outside of the generator stator wire rod is heated by the pit heater. This causes a temperature difference between the inside and outside of the wire rod, deformation, and is not energy-efficient. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a temperature regulation system and method for a pure water system of a giant water-cooled generator set in a shutdown state, so as to maintain the temperature of the unit in a constant temperature state when the unit is shut down, eliminate the influence of temperature on the liquid level of the pure water system, and thus accurately monitor whether there is leakage in the pure water system.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is: a temperature control system for the pure water system of a giant water-cooled generator set in the shutdown state, including a leakage collection mechanism connected to the technical water supply main of the technical water supply system, the connection position of the leakage collection mechanism and the technical water supply main is set downstream of the technical water supply main valve, an electric valve is provided on the leakage collection mechanism, and the leakage collection mechanism is connected to the secondary water inlet pipe of the pure water cooler of the pure water system to perform secondary cooling on the pure water cooler.

[0008] In the preferred scheme, the leakage collection mechanism includes a leakage collection pipe, a collecting pipe and a water supply pipe. The leakage collection pipe is connected to the technical water supply main pipe, the tail end of the leakage collection pipe is connected to the collecting pipe, the collecting pipe is connected to the secondary water inlet pipe of the pure water cooler through the water supply pipe, and the electric valve is arranged on the leakage collection pipe.

[0009] In a preferred solution, a check valve is provided on the water supply pipe.

[0010] In a preferred solution, when the technical water supply main valve is closed, the water filter water supply electric valve upstream of the connection position between the technical water supply main pipe and the technical water supply filter is closed, and the electric valve is opened.

[0011] In a preferred solution, the connection position between the leakage water collection mechanism and the secondary water inlet pipe of the pure water cooler is arranged upstream of the secondary water inlet main valve.

[0012] The present invention also provides a method for regulating the temperature of pure water in a shutdown state of a giant water-cooled generator set. After the unit is shut down, the technical water supply main valve is closed, the electric valve is opened, and a water leakage collection mechanism collects the water leakage of the technical water supply main valve of each unit. The water leakage is led to a pure water cooler through the water leakage collection mechanism. A part of the conveying water of a pure water pump in a pure water system is introduced into a water inlet of a three-way valve, and the other part is conveyed to a pure water cooler for cooling. The opening of the three-way valve is adjusted, and the water cooled by the pure water cooler is mixed with the uncooled water conveyed by the pure water pump, so that the temperature of the pure water in the pure water system is regulated.

[0013] In the preferred scheme, after the unit is shut down, when the pit temperature is lower than 40°C or the pure water system temperature is lower than 38°C, the pit heater arranged at the bottom of the generator set is put into operation, and when the pit temperature is greater than 45°C or the pure water system temperature is greater than 39°C, the pit heater is shut down.

[0014] The present invention provides a temperature regulation system and method for a pure water system of a giant water-cooled generator set in a shutdown state, which has the following beneficial effects: 1. By collecting the technical water supply leakage when the giant water-cooled generator set is shut down, using the heat generated during the operation of the pure water pump of the giant water-cooled generator set, and adjusting the three-way valve of the pure water system, the temperature of the unit in the shutdown state is maintained at a constant temperature, eliminating the influence of temperature on the liquid level of the pure water system, so as to accurately monitor whether there is leakage in the pure water system.

[0015] 2. Constant temperature also controls the thermal expansion and contraction of the generator stator wire rods.

[0016] 3. In addition to the original air temperature control of the pit heater, the logic of controlling the pit heater according to the pure water temperature is added to more effectively prevent condensation in the generator set when it is shut down and reduce the deformation of the stator wire rods.

[0017] 4. The present invention does not increase new energy consumption. It only achieves the purpose of accurately monitoring the leakage status of the pure water system and preventing condensation when the unit is shut down and extending the life of the generator through the comprehensive utilization of the operating logic and water leakage of existing equipment, and it is very energy-saving. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be further described below in conjunction with the accompanying drawings and embodiments: Figure 1 It is a schematic diagram of the structure of the present invention; Figure 2 It is a structural schematic diagram of the water leakage collection mechanism; Figure 3 This is a schematic diagram of the structure of the technical water supply system; Figure 4 It is the structural diagram of the pure water system; In the figure: technical water supply main pipe 1; water leakage collection mechanism 2, electric valve 201, water leakage collection pipe 202, collecting pipe 203, water supply pipe 204, check valve 205; technical water supply main valve 3; pure water cooler 4; secondary water inlet pipe 5; technical water supply filter 6; water filter water supply electric valve 7; secondary water inlet main valve 8; pure water pump 9; three-way valve 10. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0020] like Figures 1 to 4As shown, a temperature regulating system for a pure water system in a shutdown state of a giant water-cooled generator set comprises a water leakage collecting mechanism 2 connected to a technical water supply main pipe 1 of a technical water supply system, the connection position of the water leakage collecting mechanism 2 and the technical water supply main pipe 1 is arranged downstream of a technical water supply main valve 3, an electric valve 201 is arranged on the water leakage collecting mechanism 2, the water leakage collecting mechanism 2 is connected to a secondary water inlet pipe 5 of a pure water cooler 4 of the pure water system, and secondary cooling is performed on the pure water cooler 4, and a water pipe can be selected for the water leakage collecting mechanism.

[0021] The connection position between the leakage water collection mechanism 2 and the secondary water inlet pipe 5 of the pure water cooler 4 is arranged upstream of the secondary water inlet main valve 8 .

[0022] In this embodiment, if Figure 2 As shown, the leakage collection mechanism 2 includes a leakage collection pipe 202, a collecting pipe 203 and a water supply pipe 204. The leakage collection pipe 202 is connected to the technical water supply main 1, and the tail end of the leakage collection pipe 202 is connected to the collecting pipe 203. The collecting pipe 203 is connected to the secondary water inlet pipe 5 of the pure water cooler 4 through the water supply pipe 204. The electric valve 201 is arranged on the leakage collection pipe 202.

[0023] First, the water leakage after the technical water supply main valve 3 of each unit is collected, and then uniformly distributed by the collecting pipe 203 to avoid the inability to accurately adjust the pure water temperature due to inconsistent water leakage of each unit. At the same time, it is avoided that the pressure of the water leakage caused by the technical water supply main pipe 1 being too thick cannot meet the requirements.

[0024] Preferably, when the technical water supply main valve 3 is closed, the water filter water supply electric valve 7 upstream of the connection position between the technical water supply main pipe 1 and the technical water supply water filter 6 is closed, and the electric valve 201 is opened.

[0025] A leakage collection pipe 202 is installed behind the technical water supply main valve 3 to lead the leakage to the collection pipe 203. The leakage collection pipe 202 is equipped with an electric valve 201. The electric valve 201 is closed when the technical water supply main valve 3 is opened, and exits when it is closed. When the unit is shut down, in addition to the technical water supply main valve 3, the water filter water supply electric valve 7 at the water inlet of the technical water supply filter 6 is automatically closed to avoid the leakage pressure from not being able to reach the pure water system cooler due to the excessive diameter of the main pipeline. The water in the collection pipe 203 enters the pure water cooler 4 of each unit through the water supply pipe 204 to adjust the pure water temperature when the unit is shut down.

[0026] The water supply pipe 204 is provided with a check valve 205 to prevent the secondary cooling water from flowing back when the unit is running.

[0027] During the operation of the unit, the water in the pure water system is pressurized by the pure water pump, and part of the water goes directly to the three-way valve interface, and the other part of the pure water passes through the pure water cooler and enters the other interface of the three-way valve. The three-way valve controls the amount of cold and hot water entering the three-way valve by adjusting its opening. After the pure water temperature is controlled at 38°C, it flows out through the third outlet of the three-way valve and enters the generator stator wire rod. After cooling the stator wire rod, the pure water temperature rises, and after becoming hot water, it enters the pure water pump and re-enters the next cycle.

[0028] An expansion water tank is arranged at the top of the pure water system, and the expansion water tank is connected to the pure water cooling water ring pipe of the generator stator wire rod through a pipeline. The expansion water tank is used to accommodate the volume change of the pure water temperature caused by the temperature change, which is reflected in the change of the liquid level of the expansion water tank. In the startup state, since the stator will generate heat with the change of the unit load, and since heat is generated in various parts inside the generator, the temperature of the pure water flowing through the generator is getting higher and higher, until it completely flows out of the generator stator wire rod and the temperature no longer rises, but its outlet water temperature also has a fixed relationship with the liquid level of the expansion water tank. As long as the temperature change on the inlet side of the pure water pump is observed to be consistent with the change in the liquid level of the expansion water tank, it can be determined whether there is a leak in the pure water system.

[0029] In the shutdown state, since the stator itself does not generate heat, and the pure water pump keeps running in both the startup and shutdown states. In the shutdown state, as long as the temperature of the water circulation inside the pure water system is stable at around 38°C, the liquid level of the expansion water tank is a fixed value. Therefore, when the unit is shut down, as long as the liquid level of the expansion water tank is lower than this fixed value, it can be judged that there is a leak in the pure water system.

[0030] However, in the shutdown state, due to water leakage in the technical water supply of each unit, the water temperature of each part is actually inconsistent; because the unit is not running, the heat generated inside the generator is limited, resulting in limited regulating effect of the three-way valve of the pure water system; when passing through the pure water cooler, the water temperature is relatively low due to the secondary cooling effect of the technical water supply leakage on the pure water system, and when passing through the generator, the water temperature is relatively high due to the pit heater at the bottom of the pit, and the water temperature cannot be lowered to a stable level of 38°C in the shutdown state, resulting in inaccurate judgment of whether there is a leak in the pure water system.

[0031] The present invention provides a method for regulating the temperature of pure water in a shutdown state of a giant water-cooled generator set. After the unit is shut down, the technical water supply main valve 3 is closed, the electric valve 201 is opened, and the leakage water collection mechanism 2 collects the leakage of the technical water supply main valve 3 of each unit, and the leakage water is led to the pure water cooler 4 through the leakage water collection mechanism 2. A part of the conveying water of the pure water pump 9 in the pure water system is passed into a water inlet of the three-way valve 10, and the other part is conveyed to the pure water cooler 4 for cooling. The opening of the three-way valve 10 is adjusted, and the water cooled by the pure water cooler 4 is mixed with the uncooled water conveyed by the pure water pump 9, so as to regulate the temperature of the pure water in the pure water system.

[0032] By collecting the technical water supply leakage when the giant water-cooled generator set is shut down, using the heat generated during the operation of the pure water pump of the giant water-cooled generator set, and adjusting the three-way valve of the pure water system, the temperature of the unit in the shutdown state is maintained at a constant temperature, eliminating the influence of temperature on the liquid level of the pure water system, so as to accurately monitor whether there is leakage in the pure water system; at the same time, the constant temperature also controls the thermal expansion and contraction of the generator stator wire rods.

[0033] After the unit is shut down, when the pit temperature is lower than 40°C or the pure water system temperature is lower than 38°C, the pit heater arranged at the bottom of the generator set is put into operation, and when the pit temperature is greater than 45°C or the pure water system temperature is greater than 39°C, the pit heater is shut down. In the actual production process, it is found that when there is no leakage in the technical water supply, the pure water temperature is generally 10°C higher than the pit temperature. The two input conditions of the heating control logic are put into operation if any condition is met, and are shut down if any exit condition is met.

[0034] In addition to the original air temperature control of the pit heater, the logic of controlling the pit heater according to the pure water temperature is added to more effectively prevent condensation in the generator set when it is shut down and reduce the deformation of the stator wire bars.

[0035] The present invention does not increase new energy consumption, but only achieves the purpose of accurately monitoring the leakage status of the pure water system and preventing condensation when the unit is shut down, and extending the life of the generator through comprehensive utilization of the operating logic and water leakage of existing equipment, and is very energy-saving.

[0036] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A temperature control system for the pure water system of a giant water-cooled generator set in shutdown state. It is characterized in that The invention comprises a water leakage collection mechanism (2) connected to a technical water supply main pipe (1) of a technical water supply system, wherein the connection position between the water leakage collection mechanism (2) and the technical water supply main pipe (1) is arranged downstream of a technical water supply main valve (3), an electric valve (201) is arranged on the water leakage collection mechanism (2), and the water leakage collection mechanism (2) is connected to a secondary water inlet pipe (5) of a pure water cooler (4) of a pure water system, so as to perform secondary cooling on the pure water cooler (4).

2. According to claim 1, a pure water temperature control system for a giant water-cooled generator set in shutdown state, It is characterized in that The water leakage collection mechanism (2) comprises a water leakage collection pipe (202), a collecting pipe (203) and a water supply pipe (204); the water leakage collection pipe (202) is connected to the technical water supply main pipe (1); the tail end of the water leakage collection pipe (202) is connected to the collecting pipe (203); the collecting pipe (203) is connected to the secondary water inlet pipe (5) of the pure water cooler (4) via the water supply pipe (204); and the electric valve (201) is arranged on the water leakage collection pipe (202).

3. According to claim 2, a pure water temperature control system for a giant water-cooled generator set in shutdown state, It is characterized in that The water supply pipe (204) is provided with a check valve (205).

4. According to claim 1, a pure water temperature control system for a giant water-cooled generator set in shutdown state, It is characterized in that When the technical water supply main valve (3) is closed, the filter water supply electric valve (7) upstream of the connection position between the technical water supply main pipe (1) and the technical water supply filter (6) is closed, and the electric valve (201) is opened.

5. According to claim 1, a pure water temperature control system for a giant water-cooled generator set in shutdown state, It is characterized in that The connection position between the leakage water collection mechanism (2) and the secondary water inlet pipe (5) of the pure water cooler (4) is arranged upstream of the secondary water inlet main valve (8).

6. A method for regulating the pure water temperature of a giant water-cooled generator set in shutdown state. It is characterized in that After the unit is shut down, the technical water supply main valve (3) is closed, the electric valve (201) is opened, and the water leakage collection mechanism (2) collects the water leakage of the technical water supply main valve (3) of each unit. The water leakage is led to the pure water cooler (4) through the water leakage collection mechanism (2). Part of the water delivered by the pure water pump (9) in the pure water system is passed into a water inlet of the three-way valve (10), and the other part is delivered to the pure water cooler (4) for cooling. The opening of the three-way valve (10) is adjusted, and the water cooled by the pure water cooler (4) is mixed with the uncooled water delivered by the pure water pump (9) to adjust the temperature of the pure water in the pure water system.

7. A method for regulating pure water temperature in a shutdown state of a giant water-cooled generator set according to claim 6, It is characterized in that After the unit is shut down, when the pit temperature is lower than 40°C or the pure water system temperature is lower than 38°C, the pit heater arranged at the bottom of the generator set will be put into operation; when the pit temperature is greater than 45°C or the pure water system temperature is greater than 39°C, the pit heater will be shut down.

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