CN115095393A - Hydraulic Turbine Power Generation System for Redundant Flow Energy Recovery - Google Patents

Abstract

The present application relates to a hydraulic turbine power generation system for redundant flow energy recovery, comprising: a boiler feed water pump including an inlet and an outlet through which a liquid working medium is supplied to the power plant boiler at a predetermined head and flow rate; the turbine comprises an inlet, an outlet, an impeller and a rotating shaft, wherein the inlet of the turbine is connected with the outlet of the boiler feed water pump in a fluid communication way; the rotating shaft of the generator is connected with the rotating shaft of the turbine through a coupler; and the deaerator comprises a plurality of working medium inlets, a working medium outlet and at least one exhaust port, at least one of the working medium inlets is communicated and connected with the outlet of the turbine in a fluid mode, and the working medium outlet of the deaerator is communicated and connected with the inlet of the boiler feed water pump in a fluid mode. The turbine receives a preset redundant flow of working medium from a boiler feed water pump, absorbs the pressure energy of the working medium, and drives a rotating shaft of the turbine to rotate so as to generate electricity. The turbine generates electricity using only a predetermined redundant flow of boiler feed water pump.

Description

Hydraulic Turbine Power Generation System for Redundant Flow Energy Recovery

technical field

The present application relates to energy recovery and utilization in the production process of power plants, in particular, to a hydraulic turbine power generation system for energy recovery of redundant flow working medium downstream of boiler feed pumps in power plants.

Background technique

The main engine of a thermal power plant or thermal power plant includes boilers, steam turbines and generators, with coal, oil or gas as the power source, and the circulation of the working medium mainly water as the driving force, so that the steam turbine generator set generates electricity and contributes about 60% to the national grid of electricity. Thermal power plants can use waste heat to provide steam for industrial users such as petrochemical plants, as well as to provide heating for residents.

The supply of working medium to the boiler or the circulation of the working medium outside the unit is realized by the boiler feed pump. The boiler feed pump has its inherent head-flow characteristic (curve). When designing and selecting, it should match the pressure-flow required for boiler operation, that is, the head-flow of the boiler feed pump is slightly larger than the pressure required for boiler operation. -flow. However, in actual operation, the power supply of the steam turbine generator set in the power plant is controlled by the grid dispatching. With the reduction of the power supply, the amount of working medium required by the boiler decreases. The difference between the flow provided by the boiler feed pump and the flow required by the boiler can be called redundant flow. For the safe operation of the boiler feed pump, traditionally, redundant flow needs to be released by configuring the boiler feed pump recirculation system, that is, the system depressurizes part of the high temperature and high pressure water at the outlet of the boiler feed pump through the recirculation valve and returns it to the deaerator. , to ensure that the actual operating flow of the boiler feed pump at any time is not lower than the minimum flow condition requirements, and by consuming part of the energy to ensure the safe and stable operation of the boiler feed pump during startup, shutdown and rapid adjustment.

According to the national strategy to achieve carbon peaking and carbon neutrality, the state prioritizes the development of non-fossil energy, such as photovoltaic power generation, wind power, hydropower, and nuclear power, so that traditional thermal power units are gradually developing towards large capacity, high parameters and participation in deep peak regulation. , More and more units have undergone flexibility transformation, making the recirculation valve open more and more frequently and for a longer time, especially during the low power consumption at night when the unit is in a low load condition, it needs to be opened for a long time and then The circulation valve operates and therefore consumes more and more energy.

Therefore, the problem of how to recover the redundant flow of the boiler water supply system needs to be solved urgently.

SUMMARY OF THE INVENTION

The technical problem to be solved by this application is to recycle the redundant flow at the outlet of the boiler feed water pump to realize energy saving and emission reduction when the generator set of a thermal power plant or a thermal power plant is running at a low load.

In order to solve the above-mentioned technical problems, according to one aspect of the present application, a hydraulic turbine power generation system for redundant flow energy recovery is provided, comprising: a boiler feed water pump, including an inlet and an outlet, and a predetermined head and flow through the outlet are provided. Provide liquid working medium to the boiler of the power plant; turbine, including inlet, outlet, impeller and shaft, the inlet of the turbine is connected in fluid communication with the outlet of the boiler feed pump; generator, the rotating shaft of the generator is connected with the shaft through the coupling. The rotating shaft of the turbine is connected; the deaerator includes a plurality of working medium inlets, a working medium outlet and at least one exhaust port, and at least one of the plurality of working medium inlets is connected to the outlet of the turbine in fluid communication. The outlet of the working medium is connected in fluid communication with the inlet of the boiler feed pump. The turbine receives the working medium with a predetermined redundant flow rate from the boiler feed water pump, and the pressure energy of the absorbed working medium drives the rotating shaft of the turbine and drives the rotating shaft of the generator to rotate to generate electricity. The turbine generates electricity using only the predetermined redundant flow of the boiler feed pump.

According to the embodiment of the present application, the hydraulic turbine power generation system for redundant flow energy recovery may further include a main high-pressure pipeline leading from the outlet of the boiler feed pump to the boiler, and a check valve arranged on the main high-pressure pipeline in sequence, Gate valve, flow measuring device.

According to embodiments of the present application, the hydraulic turbine power generation system for redundant flow energy recovery may further include a boiler economizer, and the main piping may lead to the boiler through the boiler economizer.

According to an embodiment of the present application, the fluid communication connection between the working medium outlet of the deaerator and the inlet of the boiler feed pump may include a first pipeline and a pressure sensor, a gate valve, and a flow measuring device sequentially arranged on the first pipeline.

According to an embodiment of the present application, the connection of the inlet of the turbine and the outlet of the boiler feed pump in fluid communication may include a third line and a pressure regulating valve and a gate valve disposed on the third line.

According to an embodiment of the present application, at least one of the plurality of working medium inlets connected in fluid communication with the outlet of the turbine may include a fifth line and an isolation valve and a check valve disposed on the fifth line.

According to an embodiment of the present application, the hydraulic turbine power generation system for redundant flow energy recovery may further include a second line in fluid communication connecting the outlet of the boiler feed pump and one of the plurality of working medium inlets of the deaerator, and A pre-recirculation isolation valve, a recirculation valve, a post-recirculation isolation valve, and a check valve are provided on the second pipeline.

According to the embodiment of the present application, the boiler feed water pump may be a multi-stage centrifugal impeller series combined feed water pump.

According to an embodiment of the present application, the power generated by the generator may be integrated into the power grid of the factory through a transformer.

According to the embodiment of the present application, the boiler of the power plant can provide steam power for the peak-shaving turbo-generator set.

According to the embodiment of the present application, the working medium may be treated water and necessary chemicals dissolved in the water.

According to the embodiments of the present application, the hydraulic turbine power generation system for redundant flow energy recovery has a first operation mode, a second operation mode and a third operation mode under different operating conditions, and the first to third operation modes Switched by valve on/off in the system.

According to the embodiment of the present application, in the first operation mode, the boiler feed pump only supplies the working medium to the boiler of the power plant; in the second operation mode, the pressure regulating valve on the third pipeline is closed, and the recirculation on the second pipeline When the valve is opened, the boiler feed pump can deliver the working medium to the boiler of the power plant, and at the same time, part of the flow can be diverted through the recirculation valve on the second pipeline to maintain the safe and stable operation of the boiler feed pump; in the third operation mode, the third pipeline The pressure regulating valve of the second pipeline is opened, and the recirculation valve on the second pipeline is closed. While the boiler feed water pump can deliver the working medium to the boiler of the power plant, the working medium of the redundant flow can be supplied to the turbine through the third pipeline and drive power generation. The machine generates electricity and recovers the pressure energy of the working medium.

According to another aspect of the present application, a control system for a hydraulic turbine power generation system for redundant flow energy recovery is provided. The hydraulic turbine power generation system for redundant flow energy recovery includes collecting various working media and Deaerators for deoxidizing and degassing, boiler feed pumps for supplying working medium to power plant boilers, hydraulic turbine generator sets utilizing redundant flow of boiler feed pumps, recirculation valves for overpressure protection, and connection to deaerators. The first line connecting the outlet of the oxygenator to the inlet of the boiler feed pump, the second line connecting the outlet of the boiler feed pump to the inlet of the deaerator via the recirculation valve, and the outlet of the boiler feed pump via the hydraulic turbine generator set The third pipeline at the inlet of the hydraulic turbine, the fourth pipeline connecting the outlet of the boiler feed pump to the boiler of the power plant, and the third pipeline connecting the outlet of the hydraulic turbine of the hydraulic turbine generator set to the inlet of the deaerator. Five pipelines, control system, including: distributed computer controller DCS, based on input signals and preset algorithms to send control signals to the user end, and communicate with the main control room of the power plant; and pressure transmitters, output boiler to The pressure signal of the outlet of the water pump is sent to the distributed computer controller DCS. The distributed computer controller DCS receives the pressure signal from the outlet of the boiler feed water pump output by the pressure transmitter, and the distributed computer controller DCS divides the received pressure signal from the outlet of the boiler feed water pump into three operating modes, namely the first one. An operation mode, a second operation mode and a third operation mode, the first to third operation modes are switched by valve on/off in the system. The distributed computer controller DCS conducts the third line only in the third operating mode, and operates the hydraulic turbine generator set to generate electricity.

According to the embodiment of the present application, the control system of the hydraulic turbine power generation system for redundant flow energy recovery may further include a first pressure transmitter arranged at the outlet of the deaerator, and an inlet of the boiler feed water pump. The second pressure transmitter at the boiler feed pump, the third pressure transmitter at the outlet of the boiler feed pump, the fourth pressure transmitter at the inlet of the hydraulic turbine, and the hydraulic turbine The fifth pressure transmitter at the outlet and the sixth pressure transmitter at the inlet of the power plant boiler. The distributed computer controller DCS receives the pressure signal from the above-mentioned pressure transmitter, and in combination with the pressure signal from the pressure transmitter, comprehensively judges the operation of the hydraulic turbine power generation system for redundant flow energy recovery according to a predetermined algorithm situation, determine its next operation steps.

According to the embodiment of the present application, the first operation mode may be the operation mode when the load of the steam turbine generator set of the power plant is above 70% of the design load, and the second operation mode may be the load of the steam turbine generator set of the power plant at the design load of 60%. % to 70% of the operation mode, the third operation mode may be the operation mode when the load of the steam turbine generator set of the power plant fluctuates around 40% to 50% of the design load, and the third operation mode may also include grid-based dispatching Possible deep peaking to lower operating modes.

According to the embodiment of the present application, the control system of the hydraulic turbine power generation system for redundant flow energy recovery may further include a pressure regulating valve and a gate valve arranged on the third pipeline. In the first operation mode, the gate valve V7 and Recirculation valve V3 is closed; in the second mode of operation, recirculation valve V3 is open and gate valve V7 is closed; and in the third mode of operation, regulator valve V6 and gate valve V7 are open, and recirculation valve V3 is closed.

According to the embodiment of the present application, the control system of the hydraulic turbine power generation system for redundant flow energy recovery may further include a flow measurement device SG1 arranged at the inlet of the boiler feed pump and a flow rate arranged at the inlet of the boiler E3 of the power plant Measuring device SG2.

According to the embodiment of the present application, the control system of the hydraulic turbine power generation system for redundant flow energy recovery may further include differential pressure transmitters DPT1 and DPT2 respectively arranged at both ends of the flow measuring devices SG1 and SG2. The differential pressure signals generated by the transmitters DPT1, DPT2 are sent to the distributed computer controller DCS and the flow distribution calculation is made.

According to the embodiment of the present application, in the third operation mode, the redundant flow rate of the third pipeline is equal to the difference between the flow rates measured by the flow measurement device SG1 and the flow measurement device SG2.

According to the embodiment of the present application, the control system of the hydraulic turbine power generation system for redundant flow energy recovery may further include rotational speed measuring probes SE1 , SE2 and SE3 for monitoring the rotational speed of the hydraulic turbine. When the speed of E4 is lower than the rated speed of generator E5, the distributed computer controller DCS controls the pressure regulating valve V6 and gate valve V7 to increase the opening. When the speed of hydraulic turbine E4 is higher than the rated speed of generator E5 , the distributed computer controller DCS controls the pressure regulating valve V6 and the gate valve V7 to reduce the opening, and when the speed of the hydraulic turbine E4 is higher than the rated speed of the generator E5 and controls the pressure regulating valve V6 and the gate valve V7 to reduce the opening When the temperature is invalid, the pressure regulating valve V6 and the gate valve V7 are closed, and the recirculation valve V3 is opened.

According to an embodiment of the present application, the distributed computer controller DCS may be a subsystem of the main control room of the power plant, and in any case, the distributed computer controller DCS operates under the main control room of the power plant.

Compared with the prior art, the embodiments of the present application can at least achieve the following beneficial effects:

The hydraulic turbine power generation system for redundant flow energy recovery according to the embodiment of the present application includes a set of turbine generator sets connected between the outlet of the boiler feed water pump and the inlet of the deaerator, and the turbine receives electricity from the boiler The working medium of the predetermined redundant flow of the feed pump, the pressure of the absorbed working medium can drive the rotating shaft of the turbine and drive the rotating shaft of the generator to rotate to generate electricity, and the turbine only uses the predetermined redundant flow of the boiler feed pump to generate electricity. The recoverable redundant flow energy of the hydraulic turbine power generation system for redundant flow energy recovery according to the embodiment of the present application is huge. Taking a 1000 MW generator set as an example, the maximum recoverable energy per hour is 2300 kW, and the annual power generation is 2300 kW. The energy is about 6.9 million kWH, so it has a good energy saving effect. If this part of the energy is not recovered, the redundant flow will be decompressed through the recirculation valve and returned to the deaerator, which will increase the burden on the recirculation valve and accelerate the wear. The recirculation valve will work during the decompression process. The vaporization of the medium increases the workload of the deaerator, and the heat emission generated during the decompression process is also a pollution to the ambient air. In addition, since the turbine absorbs the redundant flow, it can reduce the deterioration of the operating conditions of the boiler feed pump when the steam turbine generator set is running at a low load, that is, when the outlet pressure is kept in a reasonable range, the flow rate of the boiler feed pump can be properly increased. Keep the boiler feed water pump running under optimal working conditions, and the excess energy consumed by the boiler feed water pump can be completely recovered and compensated in the hydraulic turbine generator set. The power generated by the hydraulic turbine generator set can be transformed directly into the power grid of the power plant after being transformed by the transformer, which reduces the power consumption of the power plant to the national grid, and the power generated by the hydraulic turbine generator set is also Can be used as a backup power supply for power plants.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present application more clearly, the accompanying drawings of the embodiments will be briefly introduced below. Obviously, the drawings in the following description only relate to some embodiments of the present application, rather than limit the present application. .

FIG. 1 is a block diagram of a hydraulic turbine power generation system for redundant flow energy recovery according to an embodiment of the present application.

2 is a block diagram of a hydraulic turbine power generation control system for redundant flow energy recovery according to an embodiment of the present application.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are some, but not all, embodiments of the present application. Based on the described embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

Unless otherwise defined, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this application belongs. The terms "first," "second," and similar terms used in the description and claims of this patent application do not denote any order, quantity, or importance, but are only used to distinguish different components. Likewise, "a" or "an" and the like do not denote a quantitative limitation, but rather denote the presence of at least one.

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

FIG. 1 is a block diagram of a hydraulic turbine power generation system for redundant flow energy recovery according to an embodiment of the present application.

As shown in FIG. 1 , according to an aspect of the present application, a hydraulic turbine power generation system for redundant flow energy recovery is provided, including a boiler feed pump E2 , a hydraulic turbine generator set and a deaerator E1 .

Boiler feed pump E2 includes inlet and outlet. The boiler feed pump E2 provides liquid working medium to the boiler of the power plant through its outlet with a predetermined head and flow.

The power plant mentioned here refers to a thermal power plant or thermal power plant in the traditional sense, that is, using coal, oil (heavy oil), gas (gas, biogas, carbon-containing mixed gas), and household waste as fuel, the working medium is heated by the boiler and driven The steam turbine drives the generator to generate electricity. The working medium mentioned here refers to treated water or a mixture of water and treatment chemicals, so the working medium may also be referred to as water herein.

According to the embodiment of the present application, the boiler feed water pump E2 may be a multi-stage centrifugal impeller series combined feed water pump.

According to the embodiment of the present application, the boiler E3 of the power plant can provide steam power for the peak-shaving turbo-generator set. For a peak-shaving power plant, as known to those skilled in the art, the power generation capacity of the generator sets of the power plant needs to be distributed through dispatching according to the power consumption of the power grid. In particular, when the power consumption peaks and the power consumption trough (that is, the so-called deep peak regulation), with the change of power generation, the water supply required by the boiler E3 is also different, but the follow-up operation of the boiler feed pump E2 changes. There will be a certain lag. According to the comprehensive consideration of the characteristics of the boiler E3 and the boiler feed pump D2, under certain working conditions, a certain amount of redundant flow will inevitably be generated between the boiler feed pump D2 and the boiler E3.

The hydraulic turbine generator set includes a turbine E4, a generator E5, and a shaft coupling that connects the turbine E4 and the generator E5.

Turbine E4, also referred to herein as a hydraulic turbine, includes an inlet, outlet, impeller and shaft (not shown in detail), the inlet of turbine E4 being connected in fluid communication with the outlet of boiler feed pump E2. According to an embodiment of the present application, the connection between the inlet of the turbine and the outlet of the boiler feed pump E2 in fluid communication may include a third pipeline T3 and a pressure regulating valve V6 and a gate valve V7 provided on the third pipeline T3. The pressure regulating valve V6 may be an electric pressure regulating valve, which opens and closes at a predetermined pressure according to the command of the control system. For example, when the outlet pressure of the boiler feed water pump E2 rises to the first predetermined pressure, the gate valve V7 is opened to conduct the third pipeline T3 from the outlet of the boiler feed water pump E2 to the inlet of the turbine E4, so as to realize the supply of the turbine to the turbine E4. E4 provides the working medium, and the turbine E4 is guaranteed to work at the rated speed of the generator E5 by adjusting the opening of the pressure regulating valve V6. When the outlet pressure of the boiler feed pump E2 continues to rise to the second predetermined pressure, the gate valve V7 is closed, and the third pipeline T3 from the outlet of the boiler feed pump E2 to the inlet of the turbine E4 is cut off, so as to stop the feed to the turbine E4. Provide working medium.

According to the embodiment of the present application, the turbine E4 may include a plurality of impellers assembled in series coaxially, the plurality of impellers respectively absorb the pressure energy of the working medium flowing therethrough, and convert the pressure energy into mechanical energy of its own rotation, thereby The main shaft that drives the turbine E4 rotates at a high speed, for example, its rotational speed may be 3600 rpm, 3000 rpm, 1500 rpm and other rotational speeds desired by those skilled in the art. Details of the turbine E4 will be described in detail later.

The rotating shaft of the generator E5 is connected with the rotating shaft of the turbine E4 through a coupling. The connection between the rotating shaft of the generator E5 and the rotating shaft of the turbine E4 may be a rigid connection or a coupled connection. The rotational speeds of generator E5 and turbine E4 may be synchronous, eg 3000 rpm. However, the embodiment of the present invention is not limited to this, but the rotational speed of the generator E5 and the turbine E4 may be 1500 rpm or 3600 rpm, or any suitable rotational speed, and those skilled in the art can follow the correspondence between the rotational speed and the number of pole pairs according to actual needs. relationship to be determined. Details of the generator E5 will be described in detail later.

The deaerator E1 includes a plurality of working medium inlets, working medium outlets and at least one exhaust port (not shown in detail). As shown in FIG. 1 , at least one of the plurality of working medium inlets is connected in fluid communication with the outlet of the turbine E4, and the working medium outlet of the deaerator E1 is connected in fluid communication with the inlet of the boiler feed pump E2. According to an embodiment of the present application, at least one of the plurality of working medium inlets connected in fluid communication with the turbine outlet may include a fifth pipeline T5 and an isolation valve V8 and a check valve V9 disposed on the fifth pipeline T5. According to the embodiment of the present application, the fluid communication connection between the working medium outlet of the deaerator E1 and the inlet of the boiler feed pump E2 may include a first pipeline T1 and a pressure sensor PT, a gate valve V1, a flow measurement device arranged on the first pipeline T1 in sequence Device SG1.

According to the actual needs of the power grid, under the predetermined working conditions of the steam turbine generator set of the power plant, the turbine receives the working medium with a predetermined redundant flow rate from the boiler feed water pump E2, and the pressure of the absorbed working medium can drive the rotating shaft of the turbine. And drive the shaft of the generator to rotate to generate electricity. The turbine generates electricity using only the predetermined redundant flow of boiler feed pump E2.

According to the embodiment of the present application, the hydraulic turbine power generation system for redundant flow energy recovery may further include a main high-pressure pipeline T4 leading from the outlet of the boiler feed pump E2 to the boiler, and a reverse pipeline T4 arranged in sequence on the main high-pressure pipeline T4. Stop valve V10, gate valve V11, flow measurement device SG2. The main high pressure pipeline T4 is the main road connecting the boiler feed pump E2 to the generator set boiler. The hydraulic turbine power generation system for redundant flow energy recovery according to the embodiment of the present application is to comply with and serve the needs of the power generation operation of the steam turbine generator set of the power plant.

According to an embodiment of the present application, the hydraulic turbine power generation system for redundant flow energy recovery may further include a boiler economizer E3, and the main piping T4 may lead to the boiler through the boiler economizer E3. The boiler economizer E3 is used at the front end of the boiler to recycle the waste heat in the flue, and it is also the preheating of the water supply at the front end of the boiler.

According to embodiments of the present application, the hydraulic turbine power generation system for redundant flow energy recovery may further include a second fluid communication connection between the outlet of the boiler feed pump E2 and one of the plurality of working medium inlets of the deaerator E1 The pipeline T2 and the pre-recirculation isolation valve V2, the recirculation valve V3, the post-recirculation isolation valve V4, and the check valve V5 provided on the second pipeline T2. As mentioned above, when the boiler feed pump E2 is in the operating conditions of startup, shutdown and rapid adjustment, under the control of the control system, the recirculation valve V3 is opened. When E4 runs at the rated speed of generator E5, the recirculation valve V3 also needs to be opened, and the redundant flow will be decompressed through the recirculation valve V3 and flow back to the deaerator. During this period, the recirculation valve V3 is subjected to a huge pressure difference, for example a pressure difference of about 17 mpa, which consumes a huge amount of pressure energy. Of course, this is also an important guarantee to ensure the normal operation of the boiler feed pump and boiler without causing accidental shutdown.

According to the embodiments of the present application, the power generated by the hydraulic turbine generator set can be integrated into the power grid of the factory through a transformer. However, the embodiment of the present application is not limited to this, but the power generated by the hydraulic turbine generator set can also be integrated into the power grid (national grid) through the transmission and transformation circuit. When the power generated by the hydraulic turbine generator set is merged into the power grid of the power plant, the power demand of the power plant on the power grid can be greatly reduced, and it can also be used as a backup power supply for the power plant of the power plant. In this case, the reliance on the diesel generator set for the standby power supply of the plant can be reduced.

According to the embodiments of the present application, the hydraulic turbine power generation system for redundant flow energy recovery has a first operation mode, a second operation mode and a third operation mode under different operating conditions, and the first to third operation modes Switched by valve on/off in the system.

According to the embodiment of the present application, in the first operation mode, the boiler feed water pump E2 only delivers the working medium to the boiler E3 of the power plant; in the second operation mode, the pressure regulating valve V7 on the third pipeline is closed, and the second pipeline T2 The recirculation valve V3 above is opened, the boiler feed pump E2 can deliver the working medium to the boiler E3 of the power plant, and at the same time, part of the flow can be diverted through the recirculation valve V3 on the second pipeline T3 to maintain the safe and stable operation of the boiler feed pump; In the third operation mode, the pressure regulating valve V7 on the third pipeline T3 is opened, the recirculation valve V3 on the second pipeline T2 is closed, and the boiler feed pump E2 can deliver the working medium to the boiler E3 of the power plant. The working medium is supplied to the turbine E4 through the third pipeline T3 and drives the generator E5 to generate electricity to recover the pressure energy of the working medium.

Hereinafter, the significance and beneficial effects of the hydraulic turbine power generation system for redundant flow energy recovery according to the embodiments of the present application will be described with reference to examples.

Table 1 Summary of the actual operation of the steam turbine generator set in a 1000MW power plant

Table 2 The operation law of the opening of the recirculation valve of the feed pump

Table 3 Comparison of Economic Benefit of Energy Recovery Effect

Conclusion: The design parameters listed in Table 3 above are calculated by taking the average value and budgeting, and one unit can save about 1.8 million yuan in electricity bills per year.

2 is a block diagram of a hydraulic turbine power generation control system for redundant flow energy recovery according to an embodiment of the present application.

As shown in FIG. 2 , according to another aspect of the present application, a control system for a hydraulic turbine power generation system for redundant flow energy recovery is provided, and the hydraulic turbine power generation system for redundant flow energy recovery includes: Deaerator E1 that collects various working mediums and deoxidizes and degass them, boiler feed water pump E2 that provides working medium to boiler E3 of power plant, hydraulic turbine generator sets E4, E5, A recirculation valve V3 for overpressure protection, and a first pipeline T1 connecting the outlet of the deaerator E1 to the inlet of the boiler feed pump E2, connecting the outlet of the boiler feed pump E2 to the outlet of the deaerator E1 via the recirculation valve V3 The second pipeline T2 of the inlet, the third pipeline T3 connected to the outlet of the boiler feed pump E2 via the inlet of the hydraulic turbines of the hydraulic turbine generator sets E4 and E5, and the outlet of the boiler feed pump E2 to the power plant boiler E3 The fourth pipeline T4, the fifth pipeline T5 connecting the outlet of the hydraulic turbine of the hydraulic turbine generator set E4 and E5 to the inlet of the deaerator E1, the control system includes: a distributed computer controller DCS, based on The input signal and the preset algorithm send the control signal to the user terminal and communicate with the main control room of the power plant; and the pressure transmitter PT3, which outputs the pressure signal of the outlet of the boiler feed pump to the distributed computer controller DCS. The distributed computer controller DCS receives the pressure signal from the outlet of the boiler feed pump output by the pressure transmitter PT3, and the distributed computer controller DCS divides the received pressure signal from the outlet of the boiler feed pump into three operating modes, namely the first operation mode. An operation mode, a second operation mode and a third operation mode, the first to third operation modes are switched by opening/closing of valves in the system. The distributed computer controller DCS conducts the third line only in the third operating mode, and operates the hydraulic turbine generator set to generate electricity.

According to the embodiment of the present application, the control system of the hydraulic turbine power generation system for redundant flow energy recovery may further include a first pressure transmitter PT1 arranged at the outlet of the deaerator E1, a boiler feed pump arranged at The second pressure transmitter PT2 at the inlet of E2, the fourth pressure transmitter PT4 arranged at the inlet of the hydraulic turbine, the fifth pressure transmitter PT5 arranged at the outlet of the hydraulic turbine, and A sixth pressure transmitter PT6 is provided at the inlet of the boiler of the power plant. The distributed computer controller DCS receives the pressure signals from the above pressure transmitters PT1, PT2, PT4, PT5, PT6, and combines the pressure signals from the pressure transmitter PT3 to comprehensively judge the redundant flow energy according to a predetermined algorithm. The operation of the recovered hydraulic turbine power generation system determines its next operation steps.

According to the embodiment of the present application, the first operation mode may be the operation mode of the outlet pressure of the boiler feed water pump when the load of the steam turbine generator set of the power plant is above 70% of the design load, and the second operation mode may be the operation mode of the steam turbine generator set of the power plant The operation mode of the outlet pressure of the boiler feed water pump when the load of the power plant is 60% to 70% of the design load, the third operation mode can be an operation mode in which the load of the steam turbine generator set of the power plant fluctuates around 40% to 50% of the design load, and The third operating mode may further include a deep peak shaving to a lower operating mode that may occur according to the scheduling of the power grid.

According to the embodiment of the present application, the control system of the hydraulic turbine power generation system for redundant flow energy recovery may further include a pressure regulating valve V6 and a gate valve V7 arranged on the third pipeline T3, and in the first operation mode, Gate valve V7 and recirculation valve V3 are closed; in the second operating mode, recirculation valve V3 is open and gate valve V7 is closed; and in the third operating mode, pressure regulating valve V6 and gate valve V7 are open, and recirculation valve V3 is closed.

According to the embodiment of the present application, the control system of the hydraulic turbine power generation system for redundant flow energy recovery may further include a flow measuring device SG1 arranged at the inlet of the boiler feed pump E2 and a flow measuring device SG1 arranged at the inlet of the boiler E3 of the power plant. Flow measurement device SG2.

According to the embodiment of the present application, the control system of the hydraulic turbine power generation system for redundant flow energy recovery may further include differential pressure transmitters DPT1 and DPT2 respectively arranged at both ends of the flow measuring devices SG1 and SG2. The differential pressure signals generated by the transmitters DPT1, DPT2 are sent to the distributed computer controller DCS and the flow distribution calculation is made.

According to the embodiment of the present application, in the third operation mode, the redundant flow rate of the third pipeline is equal to the difference between the flow rates measured by the flow measurement device SG1 and the flow measurement device SG2.

According to the embodiment of the present application, the control system of the hydraulic turbine power generation system for redundant flow energy recovery may further include rotational speed measuring probes SE1 , SE2 and SE3 for monitoring the rotational speed of the hydraulic turbine. When the speed of E4 is lower than the rated speed of generator E5, the distributed computer controller DCS controls the pressure regulating valve V6 to increase the opening. When the speed of hydraulic turbine E4 is higher than the rated speed of generator E5, the distributed The computer controller DCS controls the pressure regulating valve V6 to reduce the opening, and when the speed of the hydraulic turbine E4 is higher or lower than the rated speed of the generator E5 and the control of the opening of the pressure regulating valve V6 is invalid, the gate valve V7 is closed, And the recirculation valve V3 is opened.

According to an embodiment of the present application, the distributed computer controller DCS may be a subsystem of the main control room of the power plant, and in any case, the distributed computer controller DCS operates under the main control room of the power plant.

Below, the design parameters and control requirements of the control system of the hydraulic turbine power generation system used for redundant flow energy recovery are described by taking the 1000MW steam turbine generator set as an example with a 100% capacity boiler feed pump.

The steam turbine generator set operates in the load range of 400MW to 1000MW, and the annual average load rate is 60%. During the peak period, the power demand is strong, and the load rate remains above 80%. During the trough period, the load rate is basically maintained at 40%. It is designed with the highest efficiency at the load rate, and the estimated annual commissioning time is 3000h.

A flow measurement device SG1 is installed on the inlet side of the feed pump, and a flow measurement device SG2 is installed on the inlet side of the boiler. The recirculation flow (pipeline T2) and the flow rate of the turbine generator set (pipeline T3) are the difference between SG1 and SG2.

The outlet of the deaerator, the inlet and outlet of the feed pump, the inlet and outlet of the turbine, and the inlet of the boiler are respectively equipped with pressure detection PT1~PT6.

The recirculation valve V3 has a fast opening function, the gate valve V7 has a fast closing function, and the isolation valve V2, the isolation valve V4 and the isolation valve V8 are normally open.

The size of the grid load determines the flow and pressure of the medium required by the boiler E3, and the above requirements are met by adjusting the opening of the valve V11 and the speed of the feed pump E2.

When the unit is about to start, stop and reduce the load quickly, the recirculation valve V3 is fully opened, and the gate valve V7 is fully closed. After the standby group runs smoothly, the flow rate of the feed pump, that is, after the value of SG1 is greater than the minimum flow value of the feed pump within a certain range, the recirculation valve V3 Close slowly.

When the unit load is around 400MW to 500MW, the turbine generator set is put into operation, the gate valve V7 and the pressure regulating valve V6 are opened, and the recirculation valve V3 is closed, and the redundant high-pressure medium enters the turbine runner through the turbine inlet. After driving the turbine to work, the low-pressure medium returns to the deaerator E1 through the turbine outlet, and the turbine drives the generator to work through the coupling. The turbine shaft head is equipped with a speed measuring device, equipped with 3 redundant speed measuring probes. The signal is connected to the automatic control system DCS of the power plant. When the turbine speed is higher than the working speed of the generator, the pressure regulating valve V6 and gate valve V7 are lowered first. If the opening degree is still not satisfied, open the recirculation valve V3 moderately; when the turbine speed is higher than the generator safe speed, quickly close the valve V7 and quickly open the valve V3; when the turbine speed is lower than the generator speed At the working speed, open the gate valve V7 and the pressure regulating valve V6 to fully open and adjust the recirculation valve V3 to fully close to ensure that the turbine speed is within the working range of the generator.

When the load is running at 600MW and above, the turbine generator set is cut out, gate valve V7 is closed and V3 is recirculated.

Compared with the prior art, the embodiments of the present application can at least achieve the following beneficial effects:

The hydraulic turbine power generation system for redundant flow energy recovery according to the embodiment of the present application includes a set of turbine generator sets connected between the outlet of the boiler feed water pump and the inlet of the deaerator, and the turbine receives electricity from the boiler The working medium of the predetermined redundant flow of the feed pump, the pressure of the absorbed working medium can drive the rotating shaft of the turbine and drive the rotating shaft of the generator to rotate to generate electricity, and the turbine only uses the predetermined redundant flow of the boiler feed pump to generate electricity. The recoverable redundant flow energy of the hydraulic turbine power generation system for redundant flow energy recovery according to the embodiment of the present application is huge. Taking a 1000 MW generator set as an example, the maximum recoverable energy per hour is 2300 kW, and the annual power generation is 2300 kW. The energy is about 6.9 million kWH, so it has a good energy saving effect. If this part of the energy is not recovered, the redundant flow will be decompressed through the recirculation valve and returned to the deaerator, which will increase the burden on the recirculation valve and accelerate the wear. The recirculation valve will work during the decompression process. The vaporization of the medium increases the workload of the deaerator, and the heat emission generated during the decompression process is also a pollution to the ambient air. In addition, since the turbine absorbs the redundant flow, it can reduce the deterioration of the operating conditions of the boiler feed pump when the steam turbine generator set is running at a low load, that is, when the outlet pressure is kept in a reasonable range, the flow rate of the boiler feed pump can be properly increased. Keep the boiler feed water pump running under optimal working conditions, and the excess energy consumed by the boiler feed water pump can be completely recovered and compensated in the hydraulic turbine generator set. The power generated by the hydraulic turbine generator set can be transformed directly into the power grid of the power plant after being transformed by the transformer, which reduces the power consumption of the power plant to the national grid, and the power generated by the hydraulic turbine generator set is also Can be used as a backup power supply for power plants.

The above descriptions are only exemplary implementations of the present application, and are not intended to limit the protection scope of the present application, which is determined by the appended claims.

Claims (15)

1. A hydraulic turbine power generation system for redundant flow energy recovery, comprising: A boiler feed pump (E2), including an inlet and an outlet, through which a liquid working medium is supplied to the power plant boiler (E3) at a predetermined head and flow rate; a turbine (E4), comprising an inlet, an outlet, an impeller and a rotating shaft, the inlet of the turbine (E4) being connected in fluid communication with the outlet of the boiler feed water pump (E2); a generator (E5), the rotating shaft of the generator (E5) is connected with the rotating shaft of the turbine through a coupling; The deaerator (E1) includes a plurality of working medium inlets, a working medium outlet and at least one exhaust port, and at least one of the plurality of working medium inlets is connected in fluid communication with the outlet of the turbine (E4), so The working medium outlet of the deaerator (E1) is in fluid communication with the inlet of the boiler feed water pump (E2), Wherein, the turbine (E4) receives a predetermined redundant flow of working medium from the boiler feed water pump (E2), and absorbs the pressure energy of the working medium to drive the rotating shaft of the turbine (E4) and drive the generator The shaft of (E5) rotates to generate electricity, and Wherein, the turbine (E4) only utilizes the predetermined redundant flow of the boiler feed water pump (E2) to generate electricity. 2. The hydraulic turbine power generation system for redundant flow energy recovery according to claim 1, further comprising a main high pressure pipe (T4) leading from the outlet of the boiler feed pump (E2) to the boiler (E3) and a check valve (V10), a gate valve (V11), and a flow measurement device (SG2) sequentially arranged on the main high-pressure pipeline (T4). 3. The hydraulic turbine power generation system for redundant flow energy recovery according to claim 2, further comprising a boiler economizer, and the main pipe (T4) leads to the boiler (T4) through the boiler economizer E3). 4. The hydraulic turbine power generation system for redundant flow energy recovery according to claim 2, wherein the working medium outlet of the deaerator (E1) and the inlet fluid of the boiler feed pump (E2) The communication connection includes a first pipeline (T1), a pressure sensor (PT), a gate valve (V1), and a flow measuring device (SG1) sequentially arranged on the first pipeline (T1). 5. A hydraulic turbine power generation system for redundant flow energy recovery as claimed in claim 4, wherein the inlet of the turbine (E4) is in fluid communication with the outlet of the boiler feed pump (E2) The connection includes a third line (T3) and a pressure regulating valve (V6) and a gate valve (V7) provided on said third line (T3). 6. The hydrodynamic turbine power generation system for redundant flow energy recovery according to claim 5, wherein at least one of the plurality of working medium inlets is connected in fluid communication with the outlet of the turbine (E4) Including a fifth pipeline (T5) and an isolation valve (V8) and a check valve (V9) arranged on the fifth pipeline (T5). 7. The hydraulic turbine power generation system for redundant flow energy recovery according to claim 6, further comprising an outlet connecting the boiler feed pump (E2) and the deaerator (E1) in fluid communication. A second pipeline (T2) of one of the plurality of working medium inlets, and a pre-recirculation isolation valve (V2), a recirculation valve (V3), and a post-recirculation isolation valve provided on the second pipeline (T2) (V4), check valve (V5). 8. The hydraulic turbine power generation system for redundant flow energy recovery according to claim 1, wherein the boiler feed pump (E2) is a multi-stage centrifugal impeller series combined feed pump. 9. The hydraulic turbine power generation system for redundant flow energy recovery as claimed in claim 1, wherein the power generated by the generator is integrated into the utility power grid through a transformer. 10. The hydraulic turbine power generation system for redundant flow energy recovery according to claim 1, wherein the power plant boiler (E3) provides steam power for a peak-shaving turbo-generator set. 11. The hydraulic turbine power generation system for redundant flow energy recovery according to claim 1, wherein the working medium is treated water and necessary chemicals dissolved in the water. 12. The hydraulic turbine power generation system for redundant flow energy recovery according to claim 7, wherein the hydraulic turbine power generation system has a first operation mode and a second operation mode under different operating conditions and a third operating mode, the first to third operating modes are switched by valve on/off in the system. 13. A hydraulic turbine power generation system for redundant flow energy recovery according to claim 12, wherein, in the first operating mode, the boiler feed pump (E2) only feeds the power plant boiler (E3) ) to deliver the working medium, the gate valve (V7) on the third pipeline (T3) is closed, and the recirculation valve (V3) on the second pipeline (T2) is closed. 14. A hydro-turbine power generation system for redundant flow energy recovery according to claim 12, wherein, in the second operating mode, the gate valve (V7) on the third pipeline (T3) is closed , the recirculation valve (V3) on the second pipeline (T2) is opened, and the boiler feed water pump (E2) conveys the working medium to the power plant boiler (E3) through the second pipeline (T2). The recirculation valve (V3) diverts part of the flow to keep the boiler feed pump (E2) running safely and stably. 15. The hydraulic turbine power generation system for redundant flow energy recovery according to claim 12, wherein, in the third operating mode, the pressure regulating valve (V6) on the third line (T3) ) and the gate valve (V7) are opened, the boiler feed water pump (E2) supplies the working medium to the boiler (E3) of the power plant, and at the same time provides the redundant working medium through the third pipeline (T3) to the turbine ( E4) and drive the generator (E5) to generate electricity to recover the pressure energy of the working medium.

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