System for reducing steam consumption rate of water feeding pump turbine of thermal power generating unit

Abstract

The utility model discloses a system for reducing the steam consumption rate of a water feed pump turbine of a thermal power generating unit, which comprises a deaerator, a high-pressure heater and a water supply pipe fitting, and further comprises a return pipe fitting and an adjusting valve, and the adjusting valve comprises a quick-opening and quick-closing pneumatic ball valve, a small-flow pneumatic stop valve and a second small-flow recirculation adjusting valve. According to the utility model, the quick-opening and quick-closing pneumatic stop valve, the small-flow pneumatic stop valve and the small-flow recirculation control valve are additionally arranged. The quick-opening and quick-closing pneumatic ball valve is used for effectively avoiding the increase of energy consumption caused by inner leakage due to long-time washing of the feed pump recirculation control valve; under the condition of low flow of deep peak regulation feed water of the unit, part of feed water returns to the deaerator again through the small-flow recirculation pipe, and the problems of water temperature rise, cavitation, pressure building and the like in the pump are prevented; the problem that the steam consumption of the steam-driven feed pump is high due to the fact that the large-flow feed water recirculation control valve is protected and operates at a large opening degree is effectively solved through the small-flow recirculation pipe.

Description

TECHNICAL FIELD

[0001] The utility model relates to water supply pump equipment technical field, especially in reducing the system of steam consumption rate of thermal power generating unit water supply pump steam turbine. BACKGROUND

[0002] The water supply pump steam turbine of the thermal power plant is the equipment for the boiler water supply, the inlet is drawn from the deaerator to the water supply pre pump, the pre pump is boosted to the outlet to the steam water supply pump, the steam water supply pump is boosted to the water supply to the high pressure heater, in order to ensure that the steam water supply pump does not occur cavitation damage at low load, the steam water supply pump recirculation door is designed, since the water supply pump recirculation door is the regulating door and the pressure difference before and after is big, most of the units appear scouring internal leakage in the operation of the unit, so that the steam water supply pump output increases, since the steam water supply pump is driven by the small steam turbine, the steam consumption of the small steam turbine increases, and the energy consumption of the unit increases.

[0003] In addition, since the proportion of new energy power generation such as wind power and photovoltaic is higher and higher, the thermal power generating unit 30% or even 20% deep peak shaving becomes the norm, and the conventional steam water supply pump system Figure 2 As shown, under the unit 30% load, the steam water supply pump recirculation regulating door has not reached the opening flow, but the operation personnel open the steam water supply pump recirculation regulating door at the unit load of about 40% in order to prevent the steam water supply pump recirculation regulating door from suddenly opening due to water supply flow fluctuation, which causes the unit non-stop accident caused by improper operation, and in order to prevent the steam water supply pump recirculation regulating door from being scoured at a small opening, the minimum opening is maintained at 30% and above, which causes the steam consumption of the steam water supply pump steam turbine to increase significantly and the coal consumption of the unit to increase greatly. UTILITY MODEL CONTENTS

[0004] The utility model aims at providing a kind of system for reducing the steam consumption rate of thermal power generating unit water supply pump steam turbine.

[0005] According to one aspect of the present disclosure, the following technical solution is provided: a system for reducing the steam consumption rate of thermal power generating unit water supply pump steam turbine, comprising a deaerator, a high pressure heater and a water supply pipe, further comprising a backflow pipe and an adjusting valve, the deaerator supplies water to the high pressure heater through the water supply pipe, the backflow pipe is connected with the deaerator and the water supply pipe, and the adjusting valve comprises a quick-opening quick-closing pneumatic stop valve, a small-flow pneumatic stop valve and a small-flow second recirculation regulating door, the quick-opening quick-closing pneumatic stop valve is installed at the water inlet end of the backflow pipe, one end of the small-flow pneumatic stop valve is connected in communication with the water inlet end of the quick-opening quick-closing pneumatic stop valve, the other end of the small-flow pneumatic stop valve is connected in communication with one end of the small-flow second recirculation regulating door, and the other end of the small-flow water supply recirculation regulating door is connected in communication with the water outlet end of the backflow pipe.

[0006] The system for reducing steam consumption rate of a feed water pump turbine of a thermal power unit according to at least one embodiment of the present disclosure comprises a feed water pipe comprising, in sequence from the deaerator to the high-pressure heater position, a front pump inlet motor door, a steam-driven front pump, a steam-driven feed water pump, a check door and an outlet motor door.

[0007] The system for reducing steam consumption rate of a feed water pump turbine of a thermal power unit according to at least one embodiment of the present disclosure comprises a return pipe comprising, in sequence, a first manual cut-off door, a large-flow first recirculation regulating door and a second manual cut-off door, one end of a quick-opening quick-closing pneumatic cut-off door being connected to the water inlet end of the second manual cut-off door, the other end of the quick-opening quick-closing pneumatic cut-off door being connected to a position between the steam-driven feed water pump and the check door, and the water outlet end of the second recirculation regulating door being connected to a position between the first manual cut-off door and the first recirculation regulating door.

[0008] The system for reducing steam consumption rate of a feed water pump turbine of a thermal power unit according to at least one embodiment of the present disclosure comprises a vibration monitoring sensor installed on the pipeline connected between the check door and the outlet motor door.

[0009] The system for reducing steam consumption rate of a feed water pump turbine of a thermal power unit according to at least one embodiment of the present disclosure comprises that the maximum flow of the second recirculation regulating door is half of the maximum flow of the first recirculation regulating door.

[0010] The technical effects and advantages of the present utility model are as follows:

[0011] The present utility model adds a quick-opening quick-closing pneumatic cut-off door, a small-flow pneumatic cut-off door and a first recirculation regulating door, which can effectively avoid the increase of energy consumption caused by the long-time flushing of the feed water pump recirculation regulating door on the one hand, and can make part of the feed water return to the deaerator through the small-flow recirculation pipe under the condition of low flow of the unit during deep peak regulation, instead of through the normal large-flow feed water recirculation pipeline, thereby keeping the flow and temperature in the pump within a safe range, preventing problems such as temperature rise, cavitation and pressure build-up in the pump, and ensuring the safe and stable operation of the pump, and on the other hand, effectively reducing the high steam consumption of the steam-driven feed water pump caused by the large opening of the large-flow feed water recirculation regulating door for protection. BRIEF DESCRIPTION OF DRAWINGS

[0012] The accompanying drawings illustrate exemplary embodiments of the present disclosure and together with the description, explain the principles of the present disclosure, wherein the drawings are provided to give a further understanding of the present disclosure and are incorporated in and constitute a part of this specification.

[0013] Figure 1 is a structural diagram of the system for reducing steam consumption rate of a feed water pump turbine of a thermal power unit.

[0014] Figure 2 It is a structural diagram of the steam-driven water supply pump system in the prior art of the utility model.

[0015] The specific reference numerals in the figure are:

[0016] Deaerator; 2. High-pressure heater; 3. Electric door for pre-pump inlet; 4. Electric pre-pump; 5. Pneumatic feed water pump; 6. Check valve; 7. Electric door for outlet; 8. Quick-opening and quick-closing pneumatic stop valve; 9. High-flow first recirculation regulating valve; 10. First manual stop valve; 11. Low-flow pneumatic stop valve; 12. Low-flow second recirculation regulating valve; 13. Second manual stop valve; 14. Vibration monitoring sensor. DETAILED DESCRIPTION

[0017] For descriptive purposes, this disclosure may use spatially relative terms, such as "below," "beneath," "beneath," "below," "above," "upper," and "side (e.g., as in "sidewall")," to describe the relationship of one component to another component(s) as illustrated in the accompanying drawings. The spatially relative terms are intended to encompass different orientations of the device in use, operation, and / or manufacture in addition to the orientation depicted in the drawings. For example, if the device in the drawings is turned over, a component described as "below" or "beneath" another component or feature would then be oriented "above" the other component or feature. Thus, the exemplary term "below" can encompass both "above" and "below" orientations. Furthermore, the device may be otherwise oriented (e.g., rotated 90 degrees or at other orientations), and as such, the spatially relative descriptors used herein should be interpreted accordingly.

[0018] like Figure 1 As shown, the present invention discloses a system for reducing the steam consumption rate of a feedwater pump turbine of a thermal power unit, comprising a deaerator 1, a high-pressure heater 2 and a water supply pipe fitting, and also comprising a return pipe fitting and a regulating valve fitting. The deaerator 1 supplies water to the high-pressure heater 2 through the water supply pipe fitting, and the return pipe fitting is connected to the deaerator 1 and the water supply pipe fitting. The regulating valve fitting comprises a fast-opening and fast-closing pneumatic stop valve 8, a small-flow pneumatic stop valve 11 and a small-flow second recirculation regulating valve 12. The fast-opening and fast-closing pneumatic stop valve 8 is installed at the water inlet end of the return pipe fitting, one end of the small-flow pneumatic stop valve 11 is connected to the water inlet end of the fast-opening and fast-closing pneumatic stop valve 8, the other end of the small-flow pneumatic stop valve 11 is connected to one end of the small-flow second recirculation regulating valve 12, and the other end of the small-flow feedwater recirculation regulating valve 12 is connected to the water outlet end of the return pipe fitting.

[0019] In this embodiment, the water supply pipes include a pre-pump inlet electric door 3, an electric pre-pump 4, a pneumatic water supply pump 5, a check valve 6 and an outlet electric door 7 which are sequentially connected from the deaerator 1 to the high-pressure heater 2.

[0020] In this embodiment, the return pipe comprises a first manual cut-off valve 10, a large-flow first recirculation valve 9 and a second manual cut-off valve 13 connected in sequence, one end of the quick-opening quick-closing pneumatic cut-off valve 8 is connected to the water inlet end of the second manual cut-off valve 13, the other end of the quick-opening quick-closing pneumatic cut-off valve 8 is connected to a position between the steam-driven feed water pump 5 and the check valve 6, and the water outlet end of the small-flow second recirculation valve 12 is connected to a position between the first manual cut-off valve 10 and the large-flow first recirculation valve 9.

[0021] In this embodiment, a vibration monitoring sensor 14 is installed on the pipeline connected between the check valve 6 and the outlet electric valve 7.

[0022] In this embodiment, the maximum flow of the small-flow second recirculation valve 12 is half of the maximum flow of the large-flow first recirculation valve 9, which is used to return part of the feed water to the deaerator 1 through the minimum-flow pipe in the case of deep peak shaving of the unit, on the one hand, it can keep the flow and temperature in the pump within a safe range, prevent problems such as water temperature rise, cavitation, and pressure build-up, and ensure the safe and stable operation of the pump, on the other hand, it can effectively reduce the high steam consumption of the steam-driven feed water pump caused by the large opening of the large-flow feed water recirculation valve.

[0023] The operation mode is as follows:

[0024] (1) System operation mode for preventing erosion of the large-flow first recirculation valve 9:

[0025] When the unit load is above 30%, the quick-opening quick-closing pneumatic ball 8 is closed to prevent the large-flow first recirculation valve 9 from being eroded and leaking; at the same time, a protection opening logic is established when the steam-driven feed water pump trips or the unit load decreases to 30% (40% for single-steam-pump large-capacity units), to realize normal standby of the large-flow first recirculation valve 9; this system can effectively avoid the increase of energy consumption caused by the internal leakage of the large-flow first recirculation valve 9.

[0026] (2) Reduce the increase of steam consumption of the feed water pump caused by excessive opening of the feed water pump recirculation valve during deep peak shaving of the unit:

[0027] When the unit load is 40% during deep peak shaving, the small-flow pneumatic cut-off valve 11 is opened, the small-flow second recirculation valve 12 is opened at a flow of 50%, and the large-flow first recirculation valve 9 is operated with a 30% margin of the flow; this system can effectively protect the first recirculation valve 9 and reasonably increase the feed water flow to reduce the steam consumption of the feed water pump.

[0028] (3) Establish a steam pump operation abnormal vibration early warning model caused by low flow of the feed water pump:

[0029] According to the steam-driven feed water pump 5 outlet pressure, flow fluctuation, vibration, feed water pump shell temperature and vibration measuring point 14 of the feed water pipeline, the feed water pump cavitation or flow low monitoring analysis model is established, the early warning is realized, the operation personnel are guided to scientifically and reasonably adjust the feed water pump recirculation water quantity, and the steam consumption of the feed water pump during the deep peak regulation of the unit is maximally reduced.

[0030] In the description of the present specification, the description of the terms "one embodiment / way", "some embodiments / ways", "example", "specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment / way or example are included in at least one embodiment / way or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment / way or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments / ways or examples. In addition, the person skilled in the art can combine and combine the different embodiments / ways or examples described in the present specification and the features of the different embodiments / ways or examples without contradiction.

[0031] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0032] The person skilled in the art should understand that the above-mentioned embodiments are only for clearly illustrating the present disclosure, and are not intended to limit the scope of the present disclosure. Other changes or modifications can be made on the basis of the above disclosure, and these changes or modifications are still within the scope of the present disclosure.

Claims

1. A system for reducing the steam consumption rate of a feedwater pump turbine of a thermal power unit, comprising a deaerator, a high-pressure heater, and water supply pipes, characterized in that: It also includes a reflux pipe fitting and a regulating valve fitting. The deaerator supplies water to the high-pressure heater through a water supply pipe fitting. The reflux pipe fitting is connected to the deaerator and the water supply pipe fitting. The regulating valve fitting includes a fast-opening and fast-closing pneumatic stop valve, a small-flow pneumatic stop valve and a small-flow second recirculation regulating valve. The fast-opening and fast-closing pneumatic stop valve is installed at the water inlet end of the reflux pipe fitting. One end of the small-flow pneumatic stop valve is connected to the water inlet end of the fast-opening and fast-closing pneumatic stop valve, the other end of the small-flow pneumatic stop valve is connected to one end of the small-flow second recirculation regulating valve, and the other end of the small-flow water supply recirculation regulating valve is connected to the water outlet end of the reflux pipe fitting.

2. The system for reducing the steam consumption rate of a feedwater pump turbine of a thermal power plant according to claim 1, characterized in that: The water supply pipes include a pre-pump inlet electric door, an electric pre-pump, a steam-driven water supply pump, a check valve and an outlet electric door which are sequentially connected from the deaerator to the high-pressure heater.

3. The system for reducing the steam consumption rate of a feedwater pump turbine of a thermal power plant according to claim 2, characterized in that: The reflux pipe fitting includes a first manual stop valve, a large-flow first recirculation regulating valve and a second manual stop valve which are connected in sequence. One end of the quick-opening and quick-closing pneumatic stop valve is connected to the water inlet end of the second manual stop valve, and the other end of the quick-opening and quick-closing pneumatic stop valve is connected to the position between the pneumatic water supply pump and the check valve. The water outlet end of the second recirculation regulating valve is connected to the position between the first manual stop valve and the first recirculation regulating valve.

4. The system for reducing the steam consumption rate of a feedwater pump turbine of a thermal power plant according to claim 3, characterized in that: A vibration monitoring sensor is installed on the pipeline connecting the check valve and the outlet electric door.

5. The system for reducing the steam consumption rate of a feedwater pump turbine of a thermal power plant according to claim 1, characterized in that: The maximum flow rate of the second recirculation valve is half of the maximum flow rate of the first recirculation valve.

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