阅读说明：本技术 一种提升热力发电厂给水泵组密封水供水性能系统和方法 (System and method for improving sealing water supply performance of water supply pump set of thermal power plant ) 是由 孙伟鹏 陈建忠 林楚伟 尤亮 朱晨亮 杨宝锷 吴震海 张泽雄 郑创伟 江永 唐一 于 2020-11-24 设计创作，主要内容包括：本发明涉及热力发电厂给水泵组密封水系统技术领域,更具体地,涉及一种提升热力发电厂给水泵组密封水供水性能系统和方法,包括了凝结水泵组出口的凝结水压力母管、凝结水精处理系统、轴封加热器、增压泵、凝结水取水母管以及调节阀门、节流孔板和连接管道,在凝结水压力母管与节流孔板之间设置有3条调节管路,所述调节管路的供水端与节流孔板的进口端相连接,经节流孔板和温度调节阀与给水泵组连接持续稳定地向给水泵组供应稳流稳压的密封水。其特点是当热力发电厂机组负荷变化以及杂项用水水量变化时,节流孔板进口端的凝结水压力较高,并且稳定,保证持续稳定地向给水泵组供应的密封水。(The invention relates to the technical field of a water supply pump set sealing water system of a thermal power plant, in particular to a system and a method for improving the water supply performance of sealing water of the water supply pump set of the thermal power plant. The sealing water supply system is characterized in that when the load of a thermal power plant unit changes and the amount of miscellaneous water changes, the pressure of the condensed water at the inlet end of the throttling orifice plate is higher and stable, and the sealing water continuously and stably supplied to the water supply pump set is ensured.)

1. A system for improving the sealing water supply performance of a water supply pump set of a thermal power plant comprises a condensation water pressure main pipe at the outlet of a condensation water pump set, a condensation water fine treatment system, a shaft seal heater, a booster pump, a condensation water taking main pipe, an adjusting valve, a throttling orifice plate and a connecting pipeline.

2. The system of claim 1, wherein the regulating valve comprises a first gate valve, a second gate valve, a third gate valve, a stop valve, a check valve, a temperature regulating valve, and a flow regulating valve.

3. The system for improving the sealing water supply performance of the water supply pump set of the thermal power plant as claimed in claim 1, wherein the first adjusting pipeline is formed by sequentially connecting a condensate water taking main pipe and a first gate valve between the condensate water fine treatment system and the shaft seal heater, and a water supply end of the first gate valve is connected with an inlet end of the orifice plate.

4. The system for improving the sealing water supply performance of the water supply pump set of the thermal power plant as claimed in claim 1, wherein the second adjusting pipeline is formed by sequentially connecting a condensate water taking main pipe, a second gate valve, a booster pump and a third gate valve between the condensate water fine treatment system and the shaft seal entering heater, and a water supply end of the third gate valve is connected with an inlet end of the throttle orifice.

5. The system for improving the sealing water supply performance of a feed pump set of a thermal power plant as claimed in claim 4, wherein the outlet pipe of the booster pump is provided with a branch flow regulating pipe, and the branch flow regulating pipe is connected with the inlet pipe of the booster pump through a flow regulating valve.

6. The system for improving the sealing water supply performance of the water feed pump set of the thermal power plant as claimed in claim 1, wherein the third adjusting pipeline is provided with a stop valve and a check valve between the condensed water pressure main pipe and the condensed water fine treatment system, and the water supply end of the check valve is connected with the inlet end of the throttle orifice.

7. The system for improving the sealing water supply performance of the water supply pump set of the thermal power plant according to claim 3 or 4, wherein a boiler air supply temperature reduction water taking point, a condenser temperature reduction water taking point and other water taking points are arranged on the condensed water taking main pipe.

8. A method for improving the water supply performance of sealed water of water supply pump set in thermodynamic power plant features that the condensed water from the pressure mother pipe of condensed water is passed through 3 regulating pipelines connected to the inlet of throttle orifice plate, throttle orifice plate and temp regulating valve, and the output pressure and flow rate of sealed water are regulated according to the load variation of thermodynamic power plant and the variation of water consumption, so continuously and stably supplying sealed water with stable flow and pressure to water supply pump set.

Technical Field

The invention relates to the technical field of a sealed water system of a water supply pump set of a thermal power plant, in particular to a system and a method for improving the water supply performance of the sealed water of the water supply pump set of the thermal power plant.

Background

The insufficient pressure of the front end of sealing water of a water feed pump unit of a thermal power plant becomes one of important hidden dangers of stable and efficient operation of the water feed pump unit, and domestic power plants pay attention to the hidden dangers.

In a large thermal power generating set, a high-pressure water feed pump set is called as the heart of a power plant and is an important auxiliary machine of a modern thermal power plant.

A sealing water system is an important system in a high pressure feed water pump set. The wear associated with the high speed rotor of a high pressure feed water pump makes the seals of the high pressure feed water pump subject to frequent leakage events. The sealing failure can bring direct economic loss to enterprises and also can threaten personal safety of workers. The unstable high-pressure water pump device always has hidden troubles in the production of enterprises, and is not favorable for the normal production of the enterprises. The good sealing water system can ensure the normal work of the high-pressure water pump device and can improve the working efficiency.

The hydraulic sealing is that a certain amount of high-pressure water is introduced into the sealing cavity to play the roles of water sealing, cooling and flushing. The sealing structure is a non-contact hydrodynamic seal, and is a novel rotating shaft sealing structure developed in recent years. The hydraulic sealing structure is simple, easy to maintain, free of abrasion in working, low in failure rate and long in service life.

The seal water is usually from the outlet of a condensate pump or an auxiliary booster pump of the power plant. The supply pressure of the condensing pump is different from the internal pressure of a boiler feed water pump, so that the adjustment and control of the sealing water pressure and flow are key factors for the good operation of a hydraulic sealing system.

The feed water pressure of the feed water pump set is obviously improved along with the increase of the capacity of the thermal power generating unit. The water feed pump group is used as important equipment in the production process of a thermal power plant, the water feed pressure of the supercritical thermal power generating unit reaches more than 23MPa, and the water feed pressure of the ultra-supercritical thermal power generating unit reaches more than 30MPa, so that the hydraulic sealing difficulty is increased, leakage of a sealing system occurs sometimes, and adverse effects are caused on the normal operation of the thermal power generating unit, such as the reduction of the operation efficiency of the water feed pump, the reduction of the water feed pressure, even the damage of the water feed pump group and the like. Therefore, the hydraulic sealing system of the feed pump set is effectively controlled, the production efficiency can be improved, and the safety of the production process is ensured.

The seal water for the thermal power plant feed pump package is typically from a condensate pump. In the process of power production, the unit electrical load must be matched with the electrical load. When the electrical load of the unit is adjusted, when the flow rate and the pressure of the condensed water are changed remarkably, the supply pressure and the flow rate of the sealing water are easy to be unstable, and the continuous and stable supply of enough sealing water flow is difficult to guarantee.

The thermal power plant participates in peak shaving operation, in order to guarantee the safety margin of the sealing water pressure of the water supply pump, the rotating speed reduction of a frequency converter of a motor of the condensate pump is limited, and the throttling loss of the condensate system under the low load of a unit is large, so that the power consumption rate of the motor of the condensate pump is increased.

The seal water of the feed pump group and various water such as the desuperheating water of the condenser commonly share a condensed water taking mother pipe. When the water consumption of each item of water such as condenser desuperheating water changes remarkably, the pressure of the condensate water taking main pipe can also fluctuate greatly, so that the pressure and the flow of the sealing water of the water supply pump set fluctuate greatly, the operation of the water supply pump set is adversely affected, and even the normal operation is difficult.

Disclosure of Invention

In view of the above, the present invention is directed to a system and a method for improving the sealing water supply performance of a feed pump set of a thermal power plant, which can maintain the sealing water supply pressure and continuously and stably supply sufficient sealing water flow when the load of the set and the condensate system change, so that the whole feed pump set has better stability and higher efficiency in operation.

In order to achieve the purpose, the invention adopts the technical scheme that: the utility model provides a promote thermal power plant feed pump package sealing water supply performance system, has included condensate water pressure female pipe, condensate water fine treatment system, bearing seal heater, booster pump, condensate water intaking female pipe and adjusting valve, orifice plate and connecting tube of condensate water pump group export, is provided with 3 regulating lines between condensate water pressure female pipe and orifice plate, the water supply end of regulating line is connected with the entrance point of orifice plate, is connected with the feed pump package through orifice plate and temperature regulating valve and supplies sealing water to the feed pump package. The condensed water from the condensed water pressure main pipe is respectively connected with the inlet end of the throttle orifice plate through 3 regulating pipelines, and the sealed water is supplied to the water feed pump set through the throttle orifice plate and the temperature regulating valve.

Preferably, the first adjusting pipeline is formed by sequentially connecting a condensate water taking main pipe and a first gate valve between the condensate fine treatment system and the shaft seal heater, and a water supply end of the first gate valve is connected with an inlet end of the throttle orifice plate.

Preferably, the second regulating pipeline is formed by sequentially connecting a condensate water taking main pipe, a second gate valve, a booster pump and a third gate valve between the condensate water fine treatment system and the inlet shaft seal heater, and the water supply end of the third gate valve is connected with the inlet end of the throttle orifice plate.

Preferably, the outlet pipeline of the booster pump is provided with a flow regulating branch pipeline, and the flow regulating branch pipeline is connected with the inlet pipeline of the booster pump through a flow regulating valve.

Preferably, the third adjusting pipeline is provided with a stop valve and a check valve between the condensed water pressure main pipe and the condensed water fine treatment system, and the water supply end of the check valve is connected with the inlet end of the throttling orifice plate.

Preferably, a boiler air supply temperature reduction water taking point, a condenser temperature reduction water taking point and other water taking points are arranged on the condensed water taking main pipe.

The method for raising water supply performance of sealed water in water supply pump set of heat power plant is characterized by that the condensed water coming from condensed water pressure main pipe is passed through 3 regulating pipelines connected with inlet end of throttle orifice plate, and passed through the throttle orifice plate and temp. regulating valve, and according to the load change of heat power plant unit and other water consumption change the output supply pressure and flow rate of sealed water can be regulated, and the stable and stable sealed water can be continuously and stably supplied to water supply pump set.

Compared with the prior art, the invention has the beneficial effects that: the invention effectively solves the problems of reduced condensed water pressure and insufficient flow of a sealing water system of the water supply pump set when the load of the thermal power plant unit changes and the water amount of the miscellaneous condensed water changes by arranging 3 adjusting pipelines which can be quickly adjusted according to different changing conditions, improves the condensed water pressure of the sealing water system, ensures the supply flow of the sealing water, keeps the condensed water pressure at the inlet end of the throttle orifice plate higher and stable when the load of the thermal power plant unit changes, the parameter of the condensed water system changes and the water amount of the miscellaneous water changes, and ensures the sealing water to be continuously and stably supplied to the water supply pump set. The invention has reasonable design structure, convenient adjustment and control, strong adaptability, easy maintenance, no abrasion during working, low failure rate and long service life, and effectively ensures the long-term normal operation of the water supply pump set.

Drawings

FIG. 1 is a schematic diagram of a system for improving the sealing water supply performance of a feed pump set of a thermal power plant

The graphic symbols are illustrated as follows: 1-condensed water pressure main pipe, 2-condensed water fine treatment system, 3-shaft seal heater, 4-stop valve, 5-check valve, 6-third valve gate, 7-booster pump, 8-second valve gate, 9-first gate valve, 10-orifice plate, 11-temperature regulating valve, 12-water feed pump group, 13-low pressure heater group, 14-boiler air supply and water reducing temperature water taking point, 15-condenser water reducing temperature water taking point, 16-other water taking point, 17-condensed water taking main pipe and 18-flow regulating valve.

Detailed Description

The present invention will be further described with reference to the following embodiments. Wherein the showings are for the purpose of illustration only and are shown by way of illustration only and not in actual form, and are not to be construed as limiting the present patent; to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product; it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.

The same or similar reference numerals in the drawings of the embodiments of the present invention correspond to the same or similar components; in the description of the present invention, it should be understood that if there is an orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", etc. based on the orientation or positional relationship shown in the drawings, it is only for convenience of describing the present invention and simplifying the description, but it is not intended to indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and are not to be construed as limiting the present patent, and the specific meaning of the terms may be understood by those skilled in the art according to specific circumstances.

To further clarify the objects, features and functions of the present invention, a review board will be provided by referring to the following description of the preferred embodiments in conjunction with the accompanying drawings:

referring to fig. 1, the system of the present invention is a schematic view of a system structure, and the present invention provides a system for improving the sealing water supply performance of a water supply pump set of a thermal power plant, including a condensed water pressure main pipe 1 at an outlet of the condensed water pump set, a condensed water fine treatment system 2, a shaft seal heater 3, a booster pump 7, a condensed water taking main pipe 17, an adjusting valve, a throttle orifice plate 10 and a connecting pipeline, wherein 3 adjusting pipelines are arranged between the condensed water pressure main pipe and the throttle orifice plate, a water supply end of the adjusting pipeline is connected with an inlet end of the throttle orifice plate 10, and the adjusting pipeline is connected with the water supply pump set through the throttle orifice plate 10 and a temperature adjusting valve 11 to supply sealing water to the water.

Preferably, the first adjusting pipeline is formed by sequentially connecting a condensate water taking main pipe 17 and a first gate valve 9 between the condensate water fine treatment system 2 and the shaft seal heater 3, and a water supply end of the first gate valve 9 is connected with an inlet end of the orifice plate 10.

Preferably, the second regulating pipeline is formed by sequentially connecting a condensate water taking main pipe 17, a second gate valve 8, a booster pump 7 and a third gate valve 6 between the condensate water fine treatment system 2 and the inlet shaft seal heater 3, and the water supply end of the third gate valve 6 is connected with the inlet end of the orifice plate 10.

Preferably, the outlet pipeline of the booster pump 7 is provided with a flow regulating branch pipeline, and the flow regulating branch pipeline is connected with the inlet pipeline of the booster pump 7 through a flow regulating valve 18.

Preferably, the third adjusting pipeline is provided with a stop valve 4 and a check valve 5 between the condensed water pressure main pipe 1 and the condensed water fine treatment system 2, and the water supply end of the check valve 5 is connected with the inlet end of the orifice plate 10.

Preferably, a boiler air supply temperature-reducing water taking point 14, a condenser temperature-reducing water taking point 15 and other water taking points 16 are arranged on the condensed water taking mother 17 pipe.

The method for raising water supply performance of sealed water in water supply pump set of heat power plant is characterized by that the condensed water coming from condensed water pressure main pipe is passed through 3 regulating pipelines connected with inlet end of throttle orifice plate, and passed through the throttle orifice plate and temp. regulating valve, and according to the load change of heat power plant unit and other water consumption change the output supply pressure and flow rate of sealed water can be regulated, and the stable and stable sealed water can be continuously and stably supplied to water supply pump set.

The following non-limiting examples serve to illustrate the invention patent:

the invention discloses a system and a method for improving the sealing water supply performance of a water supply pump set of a thermal power plant, as shown in figure 1, condensed water from a condensed water pressure main pipe 1 enters a condensed water fine treatment system 2 and then passes through a shaft seal heater 3 to be used as main condensed water for a low-pressure heater group 13, and the main condensed water is a working medium for steam power cycle of the power plant. A condensate water taking main pipe 17 is led out between the condensate water fine treatment system 2 and the shaft seal heater 3. And then a plurality of branches are led out from the condensed water taking main pipe 17, wherein the branches comprise but are not limited to water using equipment for supplying sealing water to the water feeding pump set 12, a boiler air supply and temperature reduction water taking point 14, a condenser temperature reduction water taking point 15, other water using and taking points 16 and the like.

When the unit load and the pressure of the condensate water taking main pipe 17 are high, the condensate water from the condensate water pressure main pipe 1 passes through the condensate water fine treatment system 2 and then enters the shaft seal heater 3, the condensate water taking main pipe 17 and the first gate valve 9 pass through the first adjusting pipeline, the water supply end of the first gate valve 9 is connected with the inlet end of the throttle orifice plate 10, the output supply pressure of the seal water is adjusted through the throttle orifice plate 10 and the temperature adjusting valve 11, the high and stable condensate water pressure at the inlet end of the throttle orifice plate is kept, and the seal water is continuously and stably supplied to the water supply pump unit 12.

When the load of the unit changes and the pressure of the condensate water taking main pipe 17 is lower, the first gate valve 9 is closed, the condensate water from the condensate water pressure main pipe 1 is led in from the condensate water taking main pipe 17 through the second adjusting pipeline before passing through the condensate water fine treatment system 2 and entering the shaft seal heater 3, the seal water is adjusted and conveyed through the second gate valve 8, the booster pump 7 and the third gate valve 6, and the water supply end of the third gate valve 6 is connected with the inlet end of the throttle orifice plate 10. Part of the sealing water pressurized by the booster pump 7 is supplied to the feed pump group 12 through the orifice plate 10 and the temperature control valve 11 in a continuously stable output manner.

Preferably, the outlet pipeline of the booster pump 7 is provided with a flow regulating branch pipeline, and the flow regulating branch pipeline is connected with the inlet pipeline of the booster pump 7 through a flow regulating valve 18. The other part of the sealing water is merged with the condensed water from the condensed water taking main pipe 17 through the flow regulating valve 18 and enters the inlet end of the booster pump 7.

The opening of the flow regulating valve 18 is adjusted to control the inlet end pressure of the orifice plate 10 and the flow of the seal water 12. When the pre-valve pressure of the flow control valve 18 exceeds or falls below the set point of the flow control valve 18, the flow control valve 18 automatically adjusts the amount of water flow therethrough.

When the booster pump 7 and the flow regulating valve 18 need to be overhauled, the two gate valves 8 and the third gate valve 6 are closed, so that the booster pump 7 and the flow regulating valve 18 are cut off and isolated, and the overhaul and maintenance operation is convenient. When other regulating circuits are used, the second regulating circuit is closed.

When the load of the unit changes, the pressure of the condensate water taking main pipe 17 is lower, and the booster pump 7 is stopped or overhauled, the condensate water from the condensate water pressure main pipe 1 reaches the inlet end of the throttling orifice plate 10 after being conveyed by the stop valve 4 and the check valve 5, the output supply pressure of the seal water is adjusted by the throttling orifice plate 10 and the temperature adjusting valve 11, the condensate water pressure at the inlet end of the throttling orifice plate is kept higher and stable, the seal water is continuously and stably supplied to the water feed pump group 12, and the check valve 5 is arranged to prevent the problem that the loss of the output seal water pressure is reduced due to the backflow of the seal water output from the second adjusting pipeline from the third adjusting pipeline.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.