阅读说明：本技术 一种亚临界机组改进型热网疏水系统及其工作方法 (Subcritical unit improved heat supply network drainage system and working method thereof ) 是由 陈飞飞 高新勇 何晓红 徐海鹏 杨志群 许青云 吴畅 于 2020-05-18 设计创作，主要内容包括：本发明公开了一种亚临界机组改进型热网疏水系统及其工作方法,现在还没有一种结构设计合理,改造量小,操作灵活,能够有效利用疏水余热、提升回热系统热效率、保护凝结水精处理装置的亚临界机组改进型热网疏水系统。系统包括汽轮机、热网加热器、疏水泵、疏水管道、除氧器疏水管路阀门、除氧器、给水管道、热井疏水管路阀门、热井、温度监控装置、凝结水泵、凝结水精处理装置、低加管道阀门、低加管道、疏水余热利用阀门、疏水流量计、补水流量计、补水阀门、凝结水加热阀门、凝结水加热器、放热前热网供水支管、支管阀门和放热后热网供水支管,系统能源利用效率高,经济效益好,能够很好的解决亚临界机组进行凝抽背改造后的热网疏水处理问题。(The invention discloses an improved heat supply network drainage system of a subcritical unit and a working method thereof, and the improved heat supply network drainage system of the subcritical unit, which has the advantages of reasonable structural design, small modification amount, flexible operation, effective utilization of drainage waste heat, improvement of heat efficiency of a heat recovery system and protection of a condensate fine treatment device, does not exist at present. The system includes the steam turbine, the heat supply network heater, the drain pump, the drain line, oxygen-eliminating device drain line valve, the oxygen-eliminating device, the water supply pipe, hot well drain line valve, the hot well, temperature monitoring device, condensate pump, condensate water fine treatment device, it adds the pipeline valve to hang down, it adds the pipeline to hang down, drainage waste heat utilization valve, drainage flowmeter, the moisturizing valve, condensate water heating valve, the condensate water heater, heat supply network water supply branch pipe before exothermic, branch pipe valve and heat supply network water supply branch pipe after exothermic, the system energy utilization efficiency is high, and economic benefits is good, can be fine solution subcritical unit congeal take out the heat supply network drainage after the back of the body is reformed transform problem.)

1. The utility model provides a subcritical unit improved generation heat supply network drainage system, includes steam turbine (1), its characterized in that: the device comprises a heat supply network heater (2), a drain pump (3), a drain pipeline (4), a deaerator drain pipeline valve (5), a deaerator (6), a water supply pipeline (7), a hot well drain pipeline valve (8), a hot well (9), a temperature monitoring device (10), a condensate pump (11), a condensate fine treatment device (12), a low-pressure pipeline valve (13), a low-pressure pipeline (14), a drain waste heat utilization valve (15), a drain flowmeter (16), a water replenishing flowmeter (17), a water replenishing valve (18), a condensate heating valve (19), a condensate heater (20), a heat supply network water supply branch pipe (21) before heat release, a branch pipe valve (22) and a heat supply network water supply branch pipe (23) after heat release;

the heating steam extraction port of the steam turbine (1) is connected with the steam inlet of the heat supply network heater (2), the drain outlet of the heat supply network heater (2) is connected with the inlet of the drain pump (3), the outlet of the drain pump (3) is connected with the drain pipeline (4), the drain pipeline (4) is connected with the inlet of the drain pipeline valve (5) of the deaerator, the outlet of the drain pipeline valve (5) of the deaerator is connected with the drain inlet of the heat supply network of the deaerator (6), and the water supply outlet of the deaerator (6) is connected with the water supply pipeline (7); the inlet of the hot well drain pipeline valve (8) is connected to the drain pipeline (4) in a bypassing manner, the outlet of the hot well drain pipeline valve (8) is connected with the hot network drain inlet of the hot well (9), the condensed water outlet of the hot well (9) is connected with the inlet of a condensed water pump (11), the temperature monitoring device (10) is installed at the condensed water outlet of the hot well (9), the outlet of the condensed water pump (11) is connected with the inlet of a condensed water fine treatment device (12), the outlet of the condensed water fine treatment device (12) is connected with the inlet of a low pressure addition pipeline valve (13), and the outlet of the low pressure addition pipeline valve (13) is connected with a low pressure addition pipeline (14);

the inlet of the drainage waste heat utilization valve (15) is connected to the drainage pipeline (4) in a bypassing mode, the outlet of the drainage waste heat utilization valve (15) is connected with the inlet of the drainage flowmeter (16), the outlet of the water supplementing flowmeter (17) is connected with the inlet of the water supplementing valve (18), and the outlet of the water supplementing valve (18) is connected with the water supplementing inlet of the hot well (9);

the other export in the smart processing apparatus of condensate water (12) of the import of condensate water heating valve (19), the export of condensate water heating valve (19) and the low temperature side access connection of condensate water heater (20), the low temperature side export of condensate water heater (20) and the heating back condensate water access connection of oxygen-eliminating device (6), heat supply network water supply branch pipe (21) and the access connection of branch pipe valve (22) before exothermic, the export of branch pipe valve (22) and the high temperature side access connection of condensate water heater (20), the high temperature side export of condensate water heater (20) is connected with heat supply network water supply branch pipe (23) after exothermic.

2. The subcritical assembly improved heat supply network drainage system according to claim 1, wherein: the steam turbine (1) is a subcritical steam turbine set with a condensed extraction back modified.

3. The subcritical assembly improved heat supply network drainage system according to claim 1, wherein: the deaerator drain pipeline valve (5) and the hot well drain pipeline valve (8) are controlled by temperature and can be interlocked to adjust the opening of the valve according to a set value.

4. The subcritical assembly improved heat supply network drainage system according to claim 1, wherein: the drainage waste heat utilization valve (15) and the water replenishing valve (18) are controlled by flow, the opening of the valve can be automatically adjusted according to a given flow value, and the flow of the two valves is kept consistent.

5. A method for operating the drainage system of the improved heat supply network of the subcritical assembly according to any one of claims 1 to 4, wherein the method comprises the following steps: the operation steps are as follows:

1) at the beginning and end of a heating season, a steam turbine (1) extracts steam to operate, at the moment, more exhaust steam is sent to a cooling tower for cooling, the temperature of condensed water discharged into a hot well (9) is lower, the condensed water can be directly sent to a condensed water fine treatment device (12), then the condensed water is sent to a low-pressure heater through a low-pressure pipeline (14), at the moment, a low-pressure pipeline valve (13) is opened, and a condensed water heating valve (19) and a branch pipe valve (22) are both closed; the drained water of the heat supply network is directly sent to the deaerator (6), the deaerator drain pipeline valve (5) is opened at the moment, and the hot well drain pipeline valve (8), the drain waste heat utilization valve (15) and the water replenishing valve (18) are all closed;

2) in the deep cold period of a heating season, a low-pressure cylinder is cut off by a steam turbine (1) to operate, only a very small amount of exhaust steam is sent to a cooling tower at the moment, the amount of condensed water in a geothermal well (9) is correspondingly small, a drain waste heat utilization valve (15) and a water replenishing valve (18) are opened, the opening degree of the drain waste heat utilization valve (15) is automatically adjusted according to the comparison result of the measurement value of a drain flowmeter (16) and a set value, the opening degree of the water replenishing valve (18) is adjusted in a linkage mode, the measurement value of the water replenishing flowmeter (17) is consistent with the set value, part of drain water of a heat supply network can be replenished to the heat supply network through the operation, meanwhile, the supplemented water originally sent to the heat supply network is sent to the geothermal well (9), it is ensured that part of the condensed water is finely processed all the time, and a recycling pipeline does not need to be opened; because the low-pressure cylinder of the steam turbine (1) basically does not enter steam, the low-pressure system cannot heat condensed water, at the moment, a condensed water heating valve (19) and a branch pipe valve (22) are opened, a low-pressure pipeline valve (13) is closed, part of heat supply network water is used for heating the condensed water, the heated condensed water is sent into a deaerator (6), and the heat efficiency of a heat regenerative system is improved;

3) in the deep cold period of a heating season, a hot well drain pipeline valve (8) and a deaerator drain pipeline valve (5) are both opened, the measured value and the set value of a temperature monitoring device (10) are compared, the opening degrees of the two hot well drain pipeline valves (8) and the deaerator drain pipeline valve (5) are automatically interlocked and adjusted, and on the premise that the water temperature entering a condensate fine processing device (12) does not exceed the standard, as much as possible of a heat supply network drain flows back to a hot well (9).

6. The operating method of the improved heat supply network drainage system of the subcritical unit according to claim 5, wherein the operating method comprises the following steps: heating steam is discharged from a steam turbine (1), is subjected to heat release and condensation to form hydrophobic water after passing through a heat supply network heater (2), is pressurized by a hydrophobic pump (3), and flows into a deaerator (6) through a deaerator hydrophobic pipeline valve (5) to form a heat supply network hydrophobic channel under the steam extraction working condition; the drainage is pressurized by a drainage pump (3) and flows into a hot well (9) through a hot well drainage pipeline valve (8) to form a heat supply network drainage channel under the working condition of cylinder cutting; the drain is pressurized by a drain pump (3) and enters a heat supply network through a drain waste heat utilization valve (15) to form a drain waste heat utilization channel; the water supplement flows into the hot well (9) through the water supplement valve (18) to form a water supplement channel; condensed water flows out of the hot well (9), is sent to a condensed water fine treatment device (12) through a condensed water pump (11), and is sent to a low pressure pipeline (14) through a low pressure pipeline valve (13) to form a condensed water channel under the steam extraction working condition; condensed water flows out of the hot well (9), is sent to a condensed water fine treatment device (12) through a condensed water pump (11), then enters a condensed water heater (20) through a condensed water heating valve (19), and finally is sent to a deaerator (6) to form a condensed water channel under the working condition of cylinder cutting; the hot net water enters the condensed water heater (20) through a branch pipe valve (22) and then is discharged to form a hot net water supply heat release channel.

Technical Field

The invention relates to an improved heat supply network drainage system of a subcritical unit, which is a system capable of reducing the temperature of drainage water of a heat supply network and increasing the heat efficiency of a heat return system and belongs to the technical field of cogeneration.

Background

The main mode of external heating of thermal power factory is that the extraction steam turbine intermediate pressure cylinder exhaust heats the heat supply network circulating water, and the steam condensation generally gets back to the oxygen-eliminating device after becoming hydrophobic, because there is the possibility of revealing in the heat supply network heater, leads to the hydrophobic impurity that may contain of heat supply network. However, for the subcritical boiler, as the steam drum has the functions of continuous pollution discharge and periodic pollution discharge, if the drainage of the heat supply network directly returns to the deaerator, the problem of the water quality of the drainage of the heat supply network is not great for the safe operation of the whole unit.

The unit through novel back of body technical transformation is taken out to congealing can realize that the steam turbine low pressure jar operates safely under extremely low flow, and low pressure jar steam flow is extremely low this moment, leads to directly discharging the condensate water also the significantly reduced in the hot-well. When the low-pressure cylinder of the steam turbine is cut off, if the drain water of the heat supply network is completely discharged into the heat well, not only is the heat wasted, but also the drain water of the heat supply network can not be cooled to damage a condensate fine treatment system; if the drain water of the heat supply network is completely sent to the deaerator, on one hand, the deaerator system needs to be modified to adapt to the condition of the increase of the drain water amount of the heat supply network, and on the other hand, if the drain water quality of the heat supply network is in an unqualified state for a long time, the problem is solved only by continuous blowdown and periodic blowdown of a steam drum, and certain risk can exist.

When the steam turbine operates by cutting off the low-pressure cylinder, because the condensate quantity of the hot well is extremely small, if sufficient water supplement is not available, the condensate pump needs to open a recirculation pipeline to keep the pump operating normally, but energy waste is caused. After the low-pressure cylinder is cut off by the steam turbine, the low-pressure heater corresponding to the low-pressure cylinder stops running completely, and the condensed water sent into the deaerator from the original pipeline is low in temperature due to lack of a heating means, so that the heat efficiency of the unit regenerative system is influenced to a certain extent.

At present, thermal power plants are actively developing the cogeneration technology, a plurality of thermal power plants are provided with heat supply initial stations, heat is sent to each heat user through a primary pipe network, the highest circulation flow of the pipe network can reach ten thousand tons per hour, the water replenishing quantity of the heat network can reach 50-100t/h, the water replenishing quality of the heat network treated by a reverse osmosis device is high, and the water replenishing water can be completely used as raw water of a condensate fine treatment device.

To carrying on the novel subcritical unit after taking out the transformation of back of body with congealing, do not have a structural design reasonable now, the transformation volume is little, the flexible operation, can effectively utilize hydrophobic waste heat, promote the regenerative system thermal efficiency, protect the subcritical unit improved generation heat supply network drainage system of condensate fine treatment device.

Disclosure of Invention

The invention aims to integrate the prior art, improve the thermal efficiency of a heat recovery system by utilizing the waste heat of the drainage of a heat supply network and protect the subcritical unit improved heat supply network drainage system of a condensate fine treatment device. The invention has high energy utilization efficiency and good economic benefit, and can well solve the problem of heat supply network drainage treatment after the subcritical unit is subjected to novel condensation extraction back transformation.

The technical scheme adopted by the invention for solving the problems is as follows: the utility model provides a subcritical unit improved generation heat supply network drainage system, includes the steam turbine, its characterized in that: the system also comprises a heat supply network heater, a drain pump, a drain pipeline, a deaerator drain pipeline valve, a deaerator, a water supply pipeline, a hot well drain pipeline valve, a hot well, a temperature monitoring device, a condensate pump, a condensate fine treatment device, a low-pressure pipeline valve, a low-pressure pipeline, a drain waste heat utilization valve, a drain flowmeter, a water replenishing valve, a condensate heating valve, a condensate heater, a heat supply network water supply branch pipe before heat release, a branch pipe valve and a heat supply network water supply branch pipe after heat release;

the heating steam extraction port of the steam turbine is connected with the steam inlet of the heat supply network heater, the drain outlet of the heat supply network heater is connected with the inlet of the drain pump, the outlet of the drain pump is connected with the drain pipeline, the drain pipeline is connected with the inlet of the drain pipeline valve of the deaerator, the outlet of the drain pipeline valve of the deaerator is connected with the drain inlet of the heat supply network of the deaerator, and the water supply outlet of the deaerator is connected with the water supply pipeline; the inlet of the hot well drain pipeline valve is connected to a drain pipeline in a bypassing manner, the outlet of the hot well drain pipeline valve is connected with the heat supply network drain inlet of the hot well, the condensed water outlet of the hot well is connected with the inlet of a condensed water pump, the temperature monitoring device is installed near the condensed water outlet of the hot well, the outlet of the condensed water pump is connected with the inlet of a condensed water fine treatment device, the outlet of the condensed water fine treatment device is connected with the inlet of a low pressure pipeline valve, and the outlet of the low pressure pipeline valve is connected with a low pressure pipeline;

the inlet of the drain residual heat utilization valve is connected to a drain pipeline in a bypassing mode, the outlet of the drain residual heat utilization valve is connected with the inlet of a drain flowmeter, the outlet of a water replenishing flowmeter is connected with the inlet of a water replenishing valve, and the outlet of the water replenishing valve is connected with the water replenishing inlet of a hot well;

the other export near the fine processing apparatus's of condensate water export of joining of condensate water heating valve, the export of condensate water heating valve and the low temperature side access connection of condensate water heater, the low temperature side export of condensate water heater and the heating back condensate water access connection of oxygen-eliminating device, the access connection of heat supply network water supply branch pipe and branch pipe valve before exothermic, the export of branch pipe valve and the high temperature side access connection of condensate water heater, the high temperature side export of condensate water heater and the heat supply network water supply branch union coupling after exothermic.

Furthermore, the steam turbine is a subcritical steam turbine set with a condensed extraction back modified.

Furthermore, the deaerator drain pipeline valve and the hot well drain pipeline valve are controlled by temperature, and the valve opening of the valve can be adjusted in an interlocking mode according to a set value.

Furthermore, the drainage waste heat utilization valve and the water replenishing valve are controlled by flow, the opening of the valve can be automatically adjusted according to a given flow value, and the flow of the two valves is kept consistent.

The working method of the subcritical unit improved heat supply network drainage system is characterized in that: the operation steps are as follows:

1) at the beginning and end of a heating season, a steam turbine extracts steam to operate, at the moment, more exhaust steam is sent to a cooling tower to be cooled, the temperature of condensed water discharged into a hot well is lower, the condensed water can be directly sent to a condensed water fine treatment device and then sent to a low-pressure heater through a low-pressure pipeline, at the moment, a low-pressure pipeline valve is opened, and a condensed water heating valve and a branch pipe valve are closed; the drain of the heat supply network is directly sent to the deaerator, at the moment, a drain pipeline valve of the deaerator is opened, and a drain pipeline valve of the heat well, a drain waste heat utilization valve and a water replenishing valve are all closed;

2) in the deep cold period of a heating season, a steam turbine cuts off a low-pressure cylinder to operate, only a very small amount of exhaust steam is sent to a cooling tower at the moment, the amount of condensed water in a heat well is correspondingly small, a drain waste heat utilization valve and a water replenishing valve need to be opened, the opening of the drain waste heat utilization valve is automatically adjusted according to the comparison result of the measurement value of a drain flowmeter and a set value, and the opening of the water replenishing valve is adjusted in a linkage manner, so that the measurement value of the water replenishing flowmeter is consistent with the set value; because the low-pressure cylinder of the steam turbine does not basically enter steam, the low-pressure heating system cannot heat condensed water, the condensed water heating valve and the branch pipe valve can be opened at the moment, the low-pressure heating pipeline valve can be closed, part of heat supply network is used for supplying water to heat the condensed water, and the heated condensed water is sent to the deaerator to improve the heat efficiency of the heat regenerative system;

3) in the deep cold period of the heating season, the drain pipeline valves of the hot wells and the drain pipeline valves of the deaerator are opened, the measured value and the set value of the temperature monitoring device are compared, the opening of the drain pipeline valves of the two hot wells and the drain pipeline valves of the deaerator are automatically interlocked, adjusted and controlled, and on the premise that the water temperature entering the condensate fine treatment device does not exceed the standard, as much drain water of a heat supply network flows back to the hot wells as possible.

Heating steam is discharged from a steam turbine, releases heat after passing through a heat supply network heater and condenses into hydrophobic steam, is pressurized by a hydrophobic pump, and flows into a deaerator from a deaerator hydrophobic pipeline valve to form a heat supply network hydrophobic channel under the steam extraction working condition; the drain is pressurized by a drain pump and flows into a hot well through a hot well drain pipeline valve to form a hot net drain channel under the working condition of cylinder cutting; the drain is pressurized by a drain pump and enters a heat supply network through a drain waste heat utilization valve to form a drain waste heat utilization channel; the water supplement flows into the hot well through the water supplement valve to form a water supplement channel; the condensed water flows out of the hot well, is sent to a condensed water fine treatment device through a condensed water pump, and is sent to a low-pressure pipeline through a low-pressure pipeline valve to form a condensed water channel under the steam extraction working condition; the condensed water flows out of the hot well, is sent to a condensed water fine treatment device through a condensed water pump, then enters a condensed water heater through a condensed water heating valve, and finally is sent to a deaerator to form a condensed water channel under the working condition of cylinder cutting; the hot net water supply enters the condensed water heater through the branch pipe valve and then is discharged to form a hot net water supply heat release channel.

Compared with the prior art, the invention has the following advantages and effects: (1) the drain waste heat is reasonably utilized, the thermal pollution to the environment is reduced, and the economic benefit of the system is improved; (2) the condensed water heater is added, and when the low-pressure cylinder of the steam turbine is cut off, the heat return system has higher heat efficiency than the traditional mode; (3) the temperature of the condensed water in the hot well is reduced by a combined means, and the safe operation of a condensed water fine treatment device is guaranteed; (4) the recycling pipeline of the condensate pump can be prevented from being started, the pumping work is saved, and the economic benefit of the system is further improved; (5) part of the condensed water can be finely treated all the time, so that the quality of the condensed water is further ensured; (6) the system has small modification workload and high automation degree, and can operate according to actual conditions and remote instructions. (7) The structure design is reasonable, the conception is unique, the operation is stable, and the reliability is good.

Drawings

Fig. 1 is a schematic structural diagram of a modified subcritical unit heat supply network drainage system according to an embodiment of the invention.

In the figure: the system comprises a steam turbine 1, a heat supply network heater 2, a drain pump 3, a drain pipeline 4, a deaerator drain pipeline valve 5, a deaerator 6, a water supply pipeline 7, a hot well drain pipeline valve 8, a hot well 9, a temperature monitoring device 10, a condensate pump 11, a condensate fine treatment device 12, a low-pressure pipeline valve 13, a low-pressure pipeline 14, a drain waste heat utilization valve 15, a drain flowmeter 16, a water replenishing flowmeter 17, a water replenishing valve 18, a condensate heating valve 19, a condensate heater 20, a heat supply network water supply branch pipe 21 before heat release, a branch pipe valve 22 and a heat supply network water supply branch pipe 23 after heat release.

Detailed Description

The present invention will be described in further detail below by way of examples with reference to the accompanying drawings, which are illustrative of the present invention and are not to be construed as limiting the present invention.