CN204987074U - Synthesize backheat and waste heat utilization's adjustable boiler preheating of air system - Google Patents

Synthesize backheat and waste heat utilization's adjustable boiler preheating of air system Download PDF

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CN204987074U
CN204987074U CN201520722976.XU CN201520722976U CN204987074U CN 204987074 U CN204987074 U CN 204987074U CN 201520722976 U CN201520722976 U CN 201520722976U CN 204987074 U CN204987074 U CN 204987074U
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condensate water
water
arm
systemic circulation
condensate
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郝江平
魏绍清
姜平
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E20/00—Combustion technologies with mitigation potential
    • Y02E20/34—Indirect CO2mitigation, i.e. by acting on non CO2directly related matters of the process, e.g. pre-heating or heat recovery

Abstract

The utility model belongs to fields such as thermal power specifically, relate to a synthesize backheat and waste heat utilization's adjustable boiler preheating of air system. The utility model discloses make the preheating of air, waste heat utilization, regenerative cycle three combines, squeeze the reposition of redundant personnel of the condensate water of heat -transfer cycle the open systemic circulation that steam turbine high parameter drew gas and hang down the closed tiny loop that the parameter was drawn gas through low pressure feed water heater (or newly -increased heat exchanger) heat absorption increase for bypass low pressure feed water heater, according to temperature height difference distribute respectively the thermal current to, abundant optimized utilization heat source in developments ground and cold source resource, make heat energy obtain the best cascade utilization in the thermodynamic cycle of electricity generation, promote with the ability quality, reduced (img file='DDA0000805050130000011. TIF'wi='51'he='66' /) and lost. The utility model discloses can be according to the automatic method of operation of optimizing governing system of service condition's change to the energy that makes different qualities obtains cascade utilization, reduces (img file='DDA0000805050130000012. TIF'wi='47'he='76' /) the loss realizes the maximize of thermodynamic cycle efficiency and system economy nature.

Description

The adjustable boiler air preheating system of a kind of comprehensive backheat and UTILIZATION OF VESIDUAL HEAT IN
Technical field
The utility model belongs to the fields such as thermal power generation, special in boiler air preheating, therrmodynamic system extraction cycle and residual heat from boiler fume and steam turbine exhausted spare heat recovery and utilization technology field, particularly, the adjustable boiler air preheating system of a kind of comprehensive backheat and UTILIZATION OF VESIDUAL HEAT IN is related to.
Background technology
The extraction cycle of thermal power generation can reduce cold source energy, reduce mean temperature difference (reduce irreversibility and loss), improve efficiency of thermal cycle.When do not affect boiler feed temperature and draw gas with feed water mean temperature difference, the low parameter amount of drawing gas is larger, then generated energy is more, and cold source energy is less.Usually import and export parameter limit by bleeder heater vapour, water side, the more senior amount of drawing gas of steam turbine can not be too little, and the final stage amount of drawing gas can not be too large.
All the time there is heating surface normal safe and run and the unfavorable coupling factor improving generatine set heat efficiency in conventional air preheater.Increase the investment of heat-transfer surface, more flue gas heat are passed to air and can improve system thermal efficiency, but reduce exhaust gas temperature and more easily make heat-transfer surface generation cold end corrosion, cause serious stifled grey simultaneously, again reduce heat transfer efficiency.Otherwise if improve exhaust gas temperature, although can alleviate the harm of cold end corrosion and stifled ash, system thermal efficiency reduces.
Do not changing under boiler and therrmodynamic system global design, carrying out conventional air preheater design can exist great limitation.The design of air preheater outlet air temperature need meet the needs of combustion system, often needs higher hot air temperature for the boiler combustion system using low-volatile coal and colm.At this moment the exhaust gas temperature designed is often a lot of higher than flue gas acid dew point, causes very large fume afterheat loss.
Conventional air preheater all adopts fixing design parameter according to design conditions, and the exchange capability of heat of heat transmission equipment is unadjustable.By the impact of environment temperature, combustion position and boiler operating parameter etc., exhaust gas temperature is constantly change.In addition, tradition rotary regenerative air preheater is heat regenerator, heat exchanger heat-transfer surface wall temperature is also constantly change, heat exchanger cold junction heat-transfer surface wall temperature before entering fume side by air side far below wall temperature mean value, even if adopt higher exhaust gas temperature, can not guarantee that heating surface has certain safe clearance under most operating mode.Current boiler generally adopts SCR flue gas denitrification system, and SCR denitration system can improve flue gas acid dew point, and the hydrogen sulfate ammonia (NH after denitration in flue gas 4) HSO 4, the stifled ash of caking property of air preheater cold-end air can be aggravated.The wall temperature of simple raising air preheater cold-end air is conducive to alleviating the cold end corrosion of air preheater and stifled ash, but also can increase the exhaust gas temperature after air preheater, increases flue gas loss.
The design of steam air heater can meet northern area and heat air preheater intake air needs winter, improves device security, and has good backheat economy.It is negative pressure that the steam turbine last stage that temperature is lower draws gas, more problems higher as steam air heater heating vapour origin system cost, and existing steam air heater adopts the cold air lower compared with the extracted steam from turbine heating-up temperature of high parameter usually, loss is comparatively large, and its backheat economy is restricted.Existing steam air heater can as a kind of regulating measure of flue gas exhaust gas temperature, but its throw stop controlling and regulating power can not adapt to Different climate and unit load change time environment temperature and the frequent of flue-gas temperature significantly change, and be subject to steam and water bursting and thermal shock and faults frequent.
Existing most heat recovery technology mainly considers reduction exhaust gas temperature, the coupled problem of the safety and efficiency of conventional air preheater can not be solved, during winter, because air temperature is lower, after air preheater, exhaust gas temperature is also lower, gas cooler comes into operation and is restricted, and not only flue resistance loss cannot make up, and air preheater corrosion simultaneously and stifled grey problem also could not solve.Existing most heat recovery technology does not combine with unit heat regenerative system and air preheating system yet, realizes the cascade utilization of energy.Meanwhile, when designing the system of recovery waste heat, due to the restriction of waste-heat recovery device regulating power, or the heat reclaimed not necessarily can obtain optimum utilization, or reclaims the scarce capacity of heat.
High-low pressure two-stage is divided by smoke gas afterheat heat exchanger to be placed in air preheater bypass flue, although controllability and the thermal efficiency of UTILIZATION OF VESIDUAL HEAT IN can be improved, but its system and operation control complicated, cost is higher, and spatial placement large flue sharp turn head less before and after air preheater, make the flow field uniformity of heat exchanger very poor, heat exchange, stifled ash and wear condition all worsen.What is more important, although its hiigh pressure stage UTILIZATION OF VESIDUAL HEAT IN thermal efficiency is higher, but walk air preheater bypass due to partial fume and can change the former thermal balance of air preheater, reduce air preheater heat transfer amount, reduce empty pre-outlet air temperature, make waste heat directly get back to boiler utilization to reduce, increase the mean temperature difference of flue gas and afterheat heat exchanger simultaneously loss increases, and the overall efficiency of heat recovery declines.
In addition, the waste heat of current turbine discharge and low-temperature receiver utilize general not good.On the one hand, the UTILIZATION OF VESIDUAL HEAT IN of turbine discharge mainly adopts various heat pump techniques, with the external heat supply of temperature and quality promoting low temperature cold source medium, but due to environment temperature is lower need heat supply time, low-temperature receiver medium temperature and thermal source demand temperature difference larger, the heating efficiency of heat pump is lower, so the external high-quality energy that when reaching required heat supply temperature, heat pump needs is excessive, causes system economy poor.On the other hand, summer environment temperature and low-temperature receiver medium temperature higher, turbine discharge condensing rate decline, cause steam discharge vacuum to be deteriorated, reduce thermal efficiency of cycle.Because the problem of Air-cooled Unit is more outstanding, during summer environment high temperature, steam discharge parameter is even up to more than 30KPa, and some units are forced to adopt various spike cooling system.At present, because indirect air-cooled spike cooling system is comparatively complicated, equipment investment is large, and generally only gas clean-up is at about 2 ~ 5KPa, and economy is not good.Although adopt the spike type of cooling of shower water significantly can reduce equipment investment, the demineralized water that water producing cost is very high consumes excessive, and economy is also poor.
Utility model content
For the deficiency that the art such as existing boiler air preheating, therrmodynamic system extraction cycle and residual heat from boiler fume and the recycling of steam turbine exhausted spare heat exist, the utility model develops the system and method for a kind of novel air preheat, extraction cycle and residual heat from boiler fume and the comprehensive utilization of steam turbine exhausted spare heat, can according to the method for operation of the change Automatic Optimal regulating system of service condition, to make the energy of different quality obtain cascade utilization, reduce loss, realizes the maximization of efficiency of thermal cycle and system economy.
Preheating for boiler of the present utility model, backheat and bootstrap system, comprising: air preheater 8, air duct 25 and exhaust gases passes 26, is characterized in that, described system also comprises:
Empty pre-front air heater 2, empty prognosis gas cooler 7, condensate water systemic circulation arm 9, condensate water circulating water main 12, condensate water house steward 20, condensate water partial circulating arm 24, low-temperature level low-pressure heater 17 and high-temperature level low-pressure heater 15;
Described air duct 25 and exhaust gases passes 26 are all connected with described air preheater 8;
Before described sky is pre-, air heater 2 is arranged on the air duct 25 before air preheater 8 along air flow; Described empty prognosis gas cooler 7 is arranged on the exhaust gases passes 26 after air preheater 8 along flue gas flow direction;
Described low-temperature level low-pressure heater 17 and high-temperature level low-pressure heater 15 flow to be connected successively along condensate water and are arranged on condensate water house steward 20;
Before described sky is pre-, the inlet tube of the condensate water of air heater 2 is connected with condensate water circulating water main 12, and condensate water circulating water main 12 other end is connected on the condensate water house steward 20 of high-temperature level low-pressure heater 15 outlet; Before described sky is pre-, the condensate water outlet of air heater 2 is divided into two-way, one tunnel is condensate water systemic circulation arm 9, the other end of described condensate water systemic circulation arm 9 is connected to pressure lower than condensate water house steward 20 with on the therrmodynamic system miscellaneous equipment of the pressure of condensate water circulating water main 12 tie point, or the described other end of condensate water systemic circulation arm 9 and the tie point of condensate water house steward 20 are along after condensate water flows to the tie point being positioned at condensate water circulating water main 12 and condensate water house steward 20; Another road is condensate water partial circulating arm 24, and condensate water partial circulating arm 24 other end is connected with the condensate water house steward 20 of low-temperature level low-pressure heater 17 entrance; The condensate water inlet tube of described empty prognosis gas cooler 7 and outlet flow to along condensate water respectively and are connected on condensate water systemic circulation arm 9;
Described system also comprises: condensate water partial circulating arm control valve 1, condensate water systemic circulation arm control valve 3 and condensate water systemic circulation bypass valve 5;
Described condensate water partial circulating arm control valve 1 is arranged on condensate water partial circulating arm 24, and described condensate water systemic circulation arm control valve 3 is arranged on condensate water systemic circulation arm 9 before empty prognosis gas cooler 7;
Before the inlet tube of described condensate water circulating water main 12 condensate water of air heater 2 before sky is pre-, be connected between condensate water systemic circulation arm control valve 3 and empty prognosis gas cooler 7 with condensate water systemic circulation arm 9 by condensate water systemic circulation shunt valve, described condensate water systemic circulation shunt valve is provided with condensate water systemic circulation bypass valve 5;
Described condensate water partial circulating arm 24 flows to the condensate water partial circulating arm pressurization cycle pump 19 being provided with variable ratio frequency changer and regulating after condensate water partial circulating arm control valve 1 along condensate water.
According to system of the present utility model, as improvement, described exhaust gases passes 26 is provided with gas cooler exit gas temperature sensor 21 after empty prognosis gas cooler 7; Described air duct 25 is provided with air preheater inlet air temperature sensor 4 between air heater 2 and air preheater 8 before sky is pre-; On described condensate water systemic circulation arm 9 between empty prognosis gas cooler 7 and the tie point of condensate water systemic circulation shunt valve and condensate water systemic circulation arm 9, be provided with gas cooler inlet water temperature sensor 6; Described condensate water systemic circulation arm 9 is provided with after empty prognosis gas cooler 7 gas cooler outlet cooling-water temperature sensor.
According to system of the present utility model, as improvement, described condensate water circulating water main 12 is provided with the condensate water systemic circulation pump 11 that variable ratio frequency changer regulates before described condensate water systemic circulation shunt valve and condensate water circulating water main 12 tie point; Described condensate water circulating water main 12 is connected with the position of condensate water systemic circulation arm 9 after the condensate water of empty prognosis gas cooler 7 exports by empty cigarette heat exchanger condensate recirculating water pipe before the condensate water entrance of condensate water systemic circulation pump 11, described empty cigarette heat exchanger condensate recirculating water pipe is arranged and is free cigarette heat exchanger condensate water to recycle control valve 10.
According to system of the present utility model, as improvement, location arrangements condensate water systemic circulation pump 11 between condensate water systemic circulation arm 9 overhead prognosis gas cooler 7 and the tie point of condensate water systemic circulation shunt valve and condensate water systemic circulation arm 9.Or, export between sky cigarette heat exchanger condensate recirculating water pipe tie point in the condensate water of empty prognosis gas cooler 7 and also can arrange water pump 11.
According to system of the present utility model, as improvement, described condensate water partial circulating arm 24 is connected with recirculated water spray header between condensate water partial circulating arm control valve 1 and condensate water partial circulating arm pressurization cycle pump 19, after the other end of described recirculated water spray header is connected to the turbine low pressure cylinder steam drain along vapor flow direction, or the other end of described recirculated water spray header is connected to the vapour side of low-temperature level low-pressure heater 17.
According to system of the present utility model, as improvement, described condensate water partial circulating arm 24 is provided with condensate water partial circulating arm steam heater 22 between condensate water partial circulating arm control valve 1 and condensate water partial circulating arm pressurization cycle pump 19.
According to system of the present utility model, as improvement, described condensate water partial circulating arm 24 flows to along condensate water and be provided with condensate water partial circulating arm back-water valve (BWV) 18 after condensate water partial circulating arm pressurization cycle pump 19, described condensate water partial circulating arm 24 is between condensate water partial circulating arm back-water valve (BWV) 18 and condensate water partial circulating arm steam heater 22, being connected to by condensate water partial circulating shunt valve flows on the condensate water circulating water main 12 before described condensate water systemic circulation shunt valve and condensate water circulating water main 12 tie point along condensate water, described condensate water partial circulating shunt valve is provided with condensate water partial circulating bypass valve 13.
According to system of the present utility model, as improvement, described condensate water partial circulating arm 24 is connected on condensate water circulating water main 12 by condensate water partial circulating bypass valve 13, is provided with condensate water partial circulating arm steam heater 22 between condensate water partial circulating arm control valve 1 and condensate water circulating water main 12.
Be further used as improvement, described condensate water circulating water main 12 flows to before described condensate water systemic circulation shunt valve and condensate water circulating water main 12 tie point along condensate water, is connected with the position of condensate water systemic circulation arm 9 after the condensate water of empty prognosis gas cooler 7 exports by empty cigarette heat exchanger condensate recirculating water pipe; Described empty cigarette heat exchanger condensate recirculating water pipe sets gradually sky cigarette heat exchanger condensate water recirculation pump and empty cigarette heat exchanger condensate water recirculation control valve 10.
The utility model additionally provides a kind of adjustable boiler air preheat method of comprehensive backheat based on said system and UTILIZATION OF VESIDUAL HEAT IN, specifically comprises the following steps:
High-temperature flue gas in exhaust gases passes 26 flows through air preheater 8, with flow through in air duct 25 empty pre-before air heater 2 entered the air heat-exchange of air preheater 8 after heating;
Flue gas in exhaust gases passes 26 after air preheater 8 flows through sky prognosis gas cooler 7, transfers heat to the condensate water flowed through in the condensate water systemic circulation arm 9 of sky prognosis gas cooler 7; The condensate water absorbing fume afterheat gets back to the therrmodynamic system miscellaneous equipments such as condensate water house steward 20 high temperature section or oxygen-eliminating device through condensate water systemic circulation arm 9;
Air heat-exchange after condensate water in condensate water circulating water main 12 flows through empty pre-front air heater 2 and in air duct 25; The condensate water flowed through after empty pre-front air heater 2 enters in condensate water systemic circulation arm 9 and in condensate water partial circulating arm 24 respectively;
Condensate water in condensate water partial circulating arm 24 gets back to the condensate water house steward 20 of therrmodynamic system, mix with condensate water in condensate water house steward 20, flow through low-temperature level low-pressure heater 17 successively and high-temperature level low-pressure heater 15 is heated, entered condensate water circulating water main 12 by the condensate water part after heating.
Or the condensate water in condensate water partial circulating arm 24 is after recirculated water spray header enters turbine low pressure cylinder steam drain, or the condensate water in condensate water partial circulating arm 24 enters the vapour side of low-temperature level low-pressure heater 17 through recirculated water spray header.
After in described recirculated water spray header, the spout atomization of condensate water through connecting enters turbine low pressure cylinder steam drain, with turbine discharge mixed heat transfer, part turbine discharge is condensed into condensate water, decrease the heat directly being taken away discharge by low-temperature receiver, and increase turbine discharge vacuum, improve efficiency of thermal cycle; Mixed condensate water enters the low-pressure heater heat regenerative system of condensate water house steward 20 and series connection through steam turbine condensate pump;
In described recirculated water spray header, the spout atomization of condensate water through connecting enters the vapour side of low-temperature level low-pressure heater 17, with the extracted steam from turbine mixed heat transfer entered in described low-temperature level low-pressure heater 17 vapour side, part extracted steam from turbine is condensed into condensate water, thus increase the extraction flow of steam entering low-temperature level low-pressure heater 17 vapour side, add generated energy, decrease cold source energy, improve effectiveness of regenerator; Mixed condensate water enters the low-pressure heater heat regenerative system of condensate water house steward 20 and series connection through draining system and steam turbine condensate pump.
As improvement, described exhaust gases passes 26 is provided with gas cooler exit gas temperature sensor 21 after empty prognosis gas cooler 7; Described air duct 25 is provided with air preheater inlet air temperature sensor 4 between air heater 2 and air preheater 8 before sky is pre-; On described condensate water systemic circulation arm 9 between empty prognosis gas cooler 7 and the tie point of condensate water systemic circulation shunt valve and condensate water systemic circulation arm 9, be provided with gas cooler inlet water temperature sensor 6; Described condensate water systemic circulation arm 9 is provided with after empty prognosis gas cooler 7 gas cooler outlet cooling-water temperature sensor;
Described condensate water partial circulating arm control valve 1 controls its aperture according to the measured value of air preheater inlet air temperature sensor 4 and gas cooler exit gas temperature sensor 21;
Air temperature value measured by described air preheater inlet air temperature sensor 4 is lower than air preheater entering air temperature setting one value, and the aperture of condensate water partial circulating arm control valve 1 increases; Or the air temperature value measured by air preheater inlet air temperature sensor 4 is higher than air preheater entering air temperature setting one value, and the aperture of condensate water partial circulating arm control valve 1 reduces;
Flue-gas temperature value measured by described gas cooler exit gas temperature sensor 21 is higher than gas cooler exit gas temperature setting two-value, and the aperture of condensate water partial circulating arm control valve 1 reduces; Or the flue-gas temperature value measured by gas cooler exit gas temperature sensor 21 is lower than gas cooler exit gas temperature setting two-value, and the aperture of condensate water partial circulating arm control valve 1 increases;
Described condensate water systemic circulation bypass valve 5 controls its aperture according to the measured value of gas cooler exit gas temperature sensor 21, gas cooler inlet water temperature sensor 6 and gas cooler outlet cooling-water temperature sensor;
Flue-gas temperature value measured by described gas cooler exit gas temperature sensor 21 is higher than gas cooler exit gas temperature setting one value, and the aperture of condensate water systemic circulation bypass valve 5 increases; Or the flue-gas temperature value measured by gas cooler exit gas temperature sensor 21 is lower than gas cooler exit gas temperature setting one value, and the aperture of condensate water systemic circulation bypass valve 5 reduces;
Condensate water water temperature value measured by described gas cooler inlet water temperature sensor 6 is lower than gas cooler inlet water temperature setting two-value, and the aperture of condensate water systemic circulation bypass valve 5 increases; Or the condensate water water temperature value measured by gas cooler inlet water temperature sensor 6 is higher than gas cooler inlet water temperature setting two-value, and the aperture of condensate water systemic circulation bypass valve 5 reduces;
The condensate water water temperature value of described gas cooler outlet measured by cooling-water temperature sensor is lower than gas cooler outlet water temperature setting value, and the aperture of condensate water systemic circulation bypass valve 5 turns down; Or the condensate water water temperature value of gas cooler outlet measured by cooling-water temperature sensor is higher than gas cooler outlet water temperature setting value, and the aperture of condensate water systemic circulation bypass valve 5 is opened greatly;
Described condensate water systemic circulation arm control valve 3 controls its aperture according to the measured value of gas cooler inlet water temperature sensor 6 and air preheater inlet air temperature sensor 4;
Condensate water water temperature value measured by described gas cooler inlet water temperature sensor 6 is lower than gas cooler inlet water temperature setting one value, and the aperture of condensate water systemic circulation arm control valve 3 reduces; Or the condensate water water temperature value measured by gas cooler inlet water temperature sensor 6 is higher than gas cooler inlet water temperature setting one value, and the aperture of condensate water systemic circulation arm control valve 3 increases;
Air temperature value measured by described air preheater inlet air temperature sensor 4 is lower than air preheater entering air temperature setting three value, and the aperture of condensate water systemic circulation arm control valve 3 increases; Or the air temperature value measured by air preheater inlet air temperature sensor 4 is higher than air preheater entering air temperature setting three value, and the aperture of condensate water systemic circulation arm control valve 3 reduces.
As improvement, described condensate water circulating water main 12 is provided with the condensate water systemic circulation pump 11 that variable ratio frequency changer regulates before described condensate water systemic circulation shunt valve and condensate water circulating water main 12 tie point; Described condensate water circulating water main 12 is connected with the position of condensate water systemic circulation arm 9 after the condensate water of empty prognosis gas cooler 7 exports by empty cigarette heat exchanger condensate recirculating water pipe before the condensate water entrance of condensate water systemic circulation pump 11, described empty cigarette heat exchanger condensate recirculating water pipe is arranged and is free cigarette heat exchanger condensate water to recycle control valve 10;
Described condensate water partial circulating arm 24 flows to the condensate water partial circulating arm pressurization cycle pump 19 being provided with variable ratio frequency changer and regulating after condensate water partial circulating arm control valve 1 along condensate water;
Described empty cigarette heat exchanger condensate water recirculation control valve 10 controls its aperture according to the measured value of gas cooler inlet water temperature sensor 6 and air preheater inlet air temperature sensor 4;
Condensate water water temperature value measured by described gas cooler inlet water temperature sensor 6 is lower than gas cooler inlet water temperature setting three value, and the aperture of empty cigarette heat exchanger condensate water recirculation control valve 10 increases; Or the condensate water water temperature value measured by gas cooler inlet water temperature sensor 6 is higher than gas cooler inlet water temperature setting three value, and the aperture of empty cigarette heat exchanger condensate water recirculation control valve 10 reduces;
Air temperature value measured by described air preheater inlet air temperature sensor 4 is lower than air preheater entering air temperature setting two-value, and the aperture of empty cigarette heat exchanger condensate water recirculation control valve 10 increases; Or the air temperature value measured by air preheater inlet air temperature sensor 4 is higher than air preheater entering air temperature setting two-value, and the aperture of empty cigarette heat exchanger condensate water recirculation control valve 10 reduces;
Described condensate water systemic circulation pump 11 is temperature optimization controlling run frequency measured by air preheater inlet air temperature sensor 4, gas cooler inlet water temperature sensor 6, gas cooler outlet cooling-water temperature sensor and gas cooler exit gas temperature sensor 21;
Described air preheater inlet air temperature sensor 4 is worth lower than respective setting one with temperature measured by gas cooler inlet water temperature sensor 6, or described gas cooler exit gas temperature sensor 21 exports temperature measured by cooling-water temperature sensor with gas cooler and is worth higher than respective setting one, improve condensate water systemic circulation pump 11 running frequency; Or, air preheater inlet air temperature sensor 4 is worth higher than respective setting one with temperature measured by gas cooler inlet water temperature sensor 6, or described gas cooler exit gas temperature sensor 21 exports temperature measured by cooling-water temperature sensor with gas cooler and is worth lower than respective setting one, reduce condensate water systemic circulation pump 11 running frequency;
When measured by described gas cooler inlet water temperature sensor 6, temperature is lower than gas cooler inlet water temperature protection value, or temperature is lower than gas cooler exit gas temperature protection value measured by described gas cooler exit gas temperature sensor 21, condensate water systemic circulation pump 11 is stopped transport;
Described condensate water partial circulating arm pressurization cycle pump 19 temperature optimization controlling run frequency measured by air preheater inlet air temperature sensor 4 and gas cooler exit gas temperature sensor 21;
Described air preheater inlet air temperature sensor 4 is worth lower than respective setting one with temperature measured by gas cooler exit gas temperature sensor 21, improves condensate water partial circulating arm pressurization cycle pump 19 running frequency; Or air preheater inlet air temperature sensor 4 is worth higher than in respective setting one with temperature measured by gas cooler exit gas temperature sensor 21, reduce condensate water partial circulating arm pressurization cycle pump 19 running frequency.
As improvement, described condensate water partial circulating arm 24 is provided with condensate water partial circulating arm steam heater 22 between condensate water partial circulating arm control valve 1 and condensate water partial circulating arm pressurization cycle pump 19.
Described condensate water partial circulating arm 24 flows to along condensate water and be provided with condensate water partial circulating arm back-water valve (BWV) 18 after condensate water partial circulating arm pressurization cycle pump 19, described condensate water partial circulating arm 24 is between condensate water partial circulating arm back-water valve (BWV) 18 and condensate water partial circulating arm pressurization cycle pump 19, being connected to by condensate water partial circulating shunt valve flows on the condensate water circulating water main 12 before described condensate water systemic circulation shunt valve and condensate water circulating water main 12 tie point along condensate water, described condensate water partial circulating shunt valve is provided with condensate water partial circulating bypass valve 13,
Described condensate water circulating water main 12 flows to before described condensate water systemic circulation shunt valve and condensate water circulating water main 12 tie point along condensate water, is connected with the position of condensate water systemic circulation arm 9 after the condensate water of empty prognosis gas cooler 7 exports by empty cigarette heat exchanger condensate recirculating water pipe; Described empty cigarette heat exchanger condensate recirculating water pipe sets gradually sky cigarette heat exchanger condensate water recirculation pump and empty cigarette heat exchanger condensate water recirculation control valve 10;
The recirculated water of condensate water partial circulating arm 24 is got back to condensate water circulating water main 12 respectively by condensate water partial circulating bypass valve 13 and condensate water partial circulating arm back-water valve (BWV) 18;
Measured by described gas cooler inlet water temperature sensor 6, temperature is worth lower than setting one, reduces the aperture of condensate water partial circulating bypass valve 13, opens the aperture of large condensate water partial circulating arm back-water valve (BWV) 18; Or temperature is worth higher than setting one measured by gas cooler inlet water temperature sensor 6, open the aperture of large condensate water partial circulating bypass valve 13, reduce the aperture of condensate water partial circulating arm back-water valve (BWV) 18.
Described condensate water partial circulating arm pressurization cycle pump 19 temperature optimization controlling run frequency measured by air preheater inlet air temperature sensor 4 and gas cooler exit gas temperature sensor 21;
Described air preheater inlet air temperature sensor 4 is worth lower than respective setting one with temperature measured by gas cooler exit gas temperature sensor 21, improves condensate water partial circulating arm pressurization cycle pump 19 running frequency; Or air preheater inlet air temperature sensor 4 is worth higher than respective setting one with temperature measured by gas cooler exit gas temperature sensor 21, reduce condensate water partial circulating arm pressurization cycle pump 19 running frequency.
The aperture of the running frequency of described empty cigarette heat exchanger condensate water recirculation pump and empty cigarette heat exchanger condensate water recirculation control valve 10 regulates according to the measured value of gas cooler inlet water temperature sensor 6 and air preheater inlet air temperature sensor 4;
The measured value of described gas cooler inlet water temperature sensor 6 is lower than gas cooler inlet water temperature setting three value, and the aperture of empty cigarette heat exchanger condensate water recirculation control valve 10 is opened greatly; Or the measured value of gas cooler inlet water temperature sensor 6 is higher than gas cooler inlet water temperature setting three value, and the aperture of empty cigarette heat exchanger condensate water recirculation control valve 10 reduces;
The measured value of described air preheater inlet air temperature sensor 4 is lower than air preheater entering air temperature setting two-value, and the aperture of empty cigarette heat exchanger condensate water recirculation control valve 10 is opened greatly; Or the measured value of air preheater inlet air temperature sensor 4 is higher than air preheater entering air temperature setting two-value, and the aperture of empty cigarette heat exchanger condensate water recirculation control valve (10) reduces;
The measured value of described gas cooler inlet water temperature sensor 6 and air preheater inlet air temperature sensor 4 is worth lower than respective setting one, and the running frequency of empty cigarette heat exchanger condensate water recirculation pump improves; Or the measured value of described gas cooler inlet water temperature sensor 6 and air preheater inlet air temperature sensor 4 is worth higher than respective setting one, the running frequency of empty cigarette heat exchanger condensate water recirculation pump reduces.
As improvement, described condensate water partial circulating arm 24 is connected on condensate water circulating water main 12 by condensate water partial circulating bypass valve 13, is provided with condensate water partial circulating arm steam heater 22 between condensate water partial circulating arm control valve 1 and condensate water circulating water main 12;
The recirculated water of condensate water partial circulating arm 24 is got back to condensate water circulating water main 12 by condensate water partial circulating bypass valve 13.
As improvement, measure amount of sulfur contenting in smoke or flue gas acid dew point, measured amount of sulfur contenting in smoke or flue gas acid dew point measured value increase, and increase setting value and the protection value of the entering air temperature of the condensate water inlet water temperature of empty prognosis gas cooler 7, empty prognosis gas cooler 7 gas cooler exit gas temperature and air preheater 8; Or; measured amount of sulfur contenting in smoke or flue gas acid dew point measured value reduce, and reduce setting value and the protection value of the entering air temperature of the condensate water inlet water temperature of empty prognosis gas cooler 7, empty prognosis gas cooler 7 gas cooler exit gas temperature and air preheater 8.
Advantage of the present utility model is as follows:
1, the utility model makes air preheat, UTILIZATION OF VESIDUAL HEAT IN, extraction cycle three combine, the condensate water of heat transfer cycle is split into the open type systemic circulation that bypass low-pressure heater exclusion steam turbine high parameter draws gas and the enclosed partial circulating drawn gas by low-pressure heater (or newly-increased heat exchanger) heat absorption increase low parameter, according to temperature height difference distribute respectively hot-fluid to, dynamically abundant Optimum utilization thermal source and low-temperature receiver resource, reduce mean temperature difference, make heat energy in the thermodynamic cycle of generating, obtain best cascade utilization, promote by energy quality, reduce loss.By the setting of systemic circulation and lesser circulation, the utility model also enhances the independence that each parameter regulates, and system can be carried out the larger independence of adjustable range according to the requirement of the different parameters such as exhaust gas temperature and air preheating temperature and be regulated.
2, the utility model solves the unfavorable coupled problem that conventional air preheater exists, while reduction heat loss due to exhaust gas, add the entrance wind-warm syndrome of conventional air preheater and the wall temperature of afterbody heat-transfer surface.Added the heat distribution of hot-air and condensate water by automatic control realization optimization, before preventing the cold end corrosion of conventional air preheater and stifled ash under topic, improve the benefit of flue gas heat recovery.
3, condensate water cooled after adding hot-air is got back to steam turbine heat regenerative system by the utility model, carry out enclosed partial circulating, can be used for increasing the steam turbine low parameter amount of drawing gas, increase the generated energy of unit mass steam, reduce steam turbine steam discharge cold source energy, improve the efficiency of thermal cycle that backheat increases.By the condensate water of air cooling as low-temperature receiver for cooling turbine low pressure cylinder steam discharge time, not only recycle low temperature exhausted spare heat, also be equivalent to add a small amount of indirect air cooling system equipment, steam turbine steam discharge vacuum and generating efficiency can be improved, to the summer high temperature period of Air-cooled Unit, there is a certain amount of spike cooling effect.
4, the utility model first adds hot blast again by the flow process of flue gas by condensate water, primary air preheating can be played, improve the effect of conventional air pre-heater inlet air themperature, gas cooler inlet water temperature can be reduced simultaneously, the higher condensate water of the temperature that on the one hand high-temperature level low-pressure heater can be adopted to export is as recirculated water water, the exclusion low parameter that reduction bypass low-temperature level low-pressure heater causes draws gas, be conducive to the heat transfer temperature difference and the heat absorption capacity that increase gas cooler on the other hand, reduce smoke evacuation final temperature, improve the smoke duster efficiency after UTILIZATION OF VESIDUAL HEAT IN and save the desulfurizing tower spraying cooling water yield.Conventional air pre-heater inlet air themperature rising simultaneously can promote the outlet cigarette temperature of air preheater, and can improve the condensate water outlet temperature after UTILIZATION OF VESIDUAL HEAT IN like this, the steam turbine that exclusion parameter is higher draws gas, to improve the efficiency of UTILIZATION OF VESIDUAL HEAT IN thermodynamic cycle.
5, the utility model realizes the air preheat classification of conventional air preheater, isolates the gentle wind-warm syndrome of higher cigarette of two inter-stages, to improve UTILIZATION OF VESIDUAL HEAT IN benefit and to prevent cold end corrosion and stifled ash.High-temperature level can adopt the various ways such as traditional rotary regenerative air preheater, makes full use of the higher exhaust gas temperature of high-temperature level and promotes the condensing water temperature getting back to heat regenerative system, to improve the efficiency of UTILIZATION OF VESIDUAL HEAT IN.Low-temperature level employing condensate water is the elementary pre-heating system of air of intermediate heat medium, is conducive to preventing the cold end corrosion of air preheater and stifled ash, improves heat exchange efficiency.As two-stage air preheating system, namely the utility model can be applicable to the higher southern area of environment temperature, also can be used for the lower northern area of environment temperature, all has great importance to pre-stifled ash empty after reduction denitrating flue gas.Also can replace traditional steam air heater at northern area, reduce the high fault rate that traditional steam air heater causes because of steam and water bursting.In addition, because gas cooler has the mode of larger cooling and regulating power and the direct heat transfer of employing condensate water, in the exhaust gas temperature of the utility model low-sulfur coal (flue gas acid dew point is lower) in degree of depth reduction uses, there is cost advantage.
6, the layout of the utility model condensate water systemic circulation pump 11 and condensate water partial circulating arm pressurization cycle pump 19 can be determined flexibly according to system different running method, to obtain best effect.When condensate water systemic circulation pump 11 location arrangements is on condensate water circulating water main 12, the outlet of gas cooler condensate recirculating water pipe is connected on pump entry, supply-water pump and recirculation pump can be united two into one, reduce water pump quantity, determine the position of condensate water outlet backwater flexibly.Condensate water is got back to condensate water circulating water main by partial circulating arm steam heater by the utility model, also can complete and utilize low parameter to draw gas the partial circulating of heating low-temperature condensate, and not need partial circulating arm booster pump.The utility model sets up systemic circulation pump separately and partial circulating arm booster pump can make each branch road resistance balance more easily regulate respectively, each loop branch pipe booster pump that boosting requires and changes in flow rate is larger regulates separately, the drag losses of great circulation system can be reduced, improve adaptability and the economy of UTILIZATION OF VESIDUAL HEAT IN.
7, the utility model adopts best control program; by the combination of multiple, multi-level control logic and protection; adjust setting value easily and flexibly at any time; greatly enhance the adaptability causing operational factor to change to unit load and variation of ambient temperature etc.; namely realize dynamically Automatic Optimal and utilize thermal source and low-temperature receiver resource, reliably control again the security of operation of system and equipment.In addition, the utility model is by the amount of sulfur contenting in smoke monitored in real time or flue gas acid dew point, the setting values such as auto modification gas cooler inlet water temperature, exhaust gas temperature and the pre-entering air temperature of sky, reliably there is serious cold end corrosion and stifled ash in the face of keeping from heat, and greatly strengthen unit to the adaptability using coal.
Accompanying drawing explanation
The adjustable boiler air preheating system schematic diagram of Fig. 1 comprehensive backheat of the present utility model and UTILIZATION OF VESIDUAL HEAT IN.
Reference numeral
1, condensate water partial circulating arm control valve 2, empty pre-front air heater
3, condensate water systemic circulation arm control valve 4, air preheater inlet air temperature sensor
5, condensate water systemic circulation bypass valve 6, gas cooler inlet water temperature sensor
7, empty prognosis gas cooler 8, air preheater
9, condensate water systemic circulation arm 10, empty cigarette heat exchanger condensate water recirculation control valve
11, condensate water systemic circulation pump 12, condensate water circulating water main
13, condensate water partial circulating bypass valve 14, condensate water recirculated water high temperature feed water valve
15, high-temperature level low-pressure heater 16, condensate water recirculated water low temperature supplying water valve
17, low-temperature level low-pressure heater 18, condensate water partial circulating arm back-water valve (BWV)
19, condensate water partial circulating arm pressurization cycle pump 20, condensate water house steward
21, gas cooler exit gas temperature sensor 22, condensate water partial circulating arm steam heater
23, condensate water partial circulating arm water cooler 24, condensate water partial circulating arm
25, air duct 26, exhaust gases passes
Detailed description of the invention
Below in conjunction with the drawings and specific embodiments, the utility model is described in more detail.
A kind of novel comprehensive backheat that the utility model proposes and the adjustable boiler air preheating system of UTILIZATION OF VESIDUAL HEAT IN, as shown in Figure 1, system capital equipment comprises:
Empty pre-front air heater 2, empty prognosis gas cooler 7, condensate water systemic circulation arm 9, condensate water circulating water main 12, condensate water house steward 20, condensate water partial circulating arm 24, low-temperature level low-pressure heater 17 and high-temperature level low-pressure heater 15;
Described air duct 25 and exhaust gases passes 26 are all connected with described air preheater 8; Partial heat to be passed to the air in air duct 25 by the flue gas in exhaust gases passes 26 by described air preheater 8;
Before described sky is pre-, air heater 2 is arranged on the air duct 25 before air preheater 8 along air flow; Described empty prognosis gas cooler 7 is arranged on the exhaust gases passes 26 after air preheater 8 along flue gas flow direction;
Described low-temperature level low-pressure heater 17 and high-temperature level low-pressure heater 15 flow to be connected successively along condensate water and are arranged on condensate water house steward 20;
Before described sky is pre-, the inlet tube of the condensate water of air heater 2 is connected with condensate water circulating water main 12, and condensate water circulating water main 12 other end is connected on the condensate water house steward 20 of high-temperature level low-pressure heater 15 outlet; Before described sky is pre-, the condensate water outlet of air heater 2 is divided into two-way, one tunnel is condensate water systemic circulation arm 9, the other end of described condensate water systemic circulation arm 9 is connected to pressure lower than condensate water house steward 20 with in the deaerator equipment of the pressure of condensate water circulating water main 12 tie point, or the described other end of condensate water systemic circulation arm 9 and the tie point of condensate water house steward 20 are along after condensate water flows to the tie point being positioned at condensate water circulating water main 12 and condensate water house steward 20; Another road is condensate water partial circulating arm 24, and condensate water partial circulating arm 24 other end is connected with the condensate water house steward 20 of low-temperature level low-pressure heater 17 entrance; The condensate water inlet tube of described empty prognosis gas cooler 7 and outlet flow to along condensate water respectively and are connected on condensate water systemic circulation arm 9;
Described system also comprises: condensate water partial circulating arm control valve 1, condensate water systemic circulation arm control valve 3 and condensate water systemic circulation bypass valve 5;
Described condensate water partial circulating arm 24 flows to the condensate water partial circulating arm pressurization cycle pump 19 being provided with variable ratio frequency changer and regulating after condensate water partial circulating arm control valve 1 along condensate water.
Described condensate water partial circulating arm control valve 1 is arranged on condensate water partial circulating arm 24, and described condensate water systemic circulation arm control valve 3 is arranged on condensate water systemic circulation arm 9 before empty prognosis gas cooler 7;
Before the inlet tube of described condensate water circulating water main 12 condensate water of air heater 2 before sky is pre-, be connected between condensate water systemic circulation arm control valve 3 and empty prognosis gas cooler 7 with condensate water systemic circulation arm 9 by condensate water systemic circulation shunt valve, described condensate water systemic circulation shunt valve is provided with condensate water systemic circulation bypass valve 5.
According to system of the present utility model, as improvement, described exhaust gases passes 26 is provided with gas cooler exit gas temperature sensor 21 after empty prognosis gas cooler 7; Described air duct 25 is provided with air preheater inlet air temperature sensor 4 between air heater 2 and air preheater 8 before sky is pre-; On described condensate water systemic circulation arm 9 between empty prognosis gas cooler 7 and the tie point of condensate water systemic circulation shunt valve and condensate water systemic circulation arm 9, be provided with gas cooler inlet water temperature sensor 6; On described condensate water systemic circulation arm 9, after empty prognosis gas cooler 7, (along condensate water flow direction) is provided with gas cooler outlet cooling-water temperature sensor, the aperture of condensate water systemic circulation bypass valve 5 can be controlled, to regulate the condensing water flow in condensate water systemic circulation arm 9 according to the temperature value of this sensor measurement.
According to system of the present utility model, as improvement, described condensate water circulating water main 12 is provided with the condensate water systemic circulation pump 11 that variable ratio frequency changer regulates before described condensate water systemic circulation shunt valve and condensate water circulating water main 12 tie point; Described condensate water circulating water main 12 is connected with the position of condensate water systemic circulation arm 9 after the condensate water of empty prognosis gas cooler 7 exports by empty cigarette heat exchanger condensate recirculating water pipe before the condensate water entrance of condensate water systemic circulation pump 11, described empty cigarette heat exchanger condensate recirculating water pipe is arranged and is free cigarette heat exchanger condensate water to recycle control valve 10.
According to system of the present utility model, as improvement, location arrangements condensate water systemic circulation pump 11 between condensate water systemic circulation arm 9 overhead prognosis gas cooler 7 and the tie point of condensate water systemic circulation shunt valve and condensate water systemic circulation arm 9.Or, export between sky cigarette heat exchanger condensate recirculating water pipe tie point in the condensate water of empty prognosis gas cooler 7 and also can arrange water pump 11.
According to system of the present utility model, as improvement, described condensate water partial circulating arm 24 is connected with recirculated water spray header between condensate water partial circulating arm control valve 1 and condensate water partial circulating arm pressurization cycle pump 19, after the other end of described recirculated water spray header is connected to the turbine low pressure cylinder steam drain along vapor flow direction, or the other end of described recirculated water spray header is connected to the vapour side of low-temperature level low-pressure heater 17.
According to system of the present utility model, as improvement, described condensate water partial circulating arm 24 is provided with condensate water partial circulating arm steam heater 22 between condensate water partial circulating arm control valve 1 and condensate water partial circulating arm pressurization cycle pump 19; The heating steam of described condensate water partial circulating arm steam heater 22 is drawn gas from turbine discharge or low pressure (LP) cylinder final stage low parameter.
According to system of the present utility model, as improvement, described condensate water partial circulating arm 24 is connected on condensate water circulating water main 12 by condensate water partial circulating bypass valve 13, is provided with condensate water partial circulating arm steam heater 22 between condensate water partial circulating arm control valve 1 and condensate water circulating water main 12.
According to system of the present utility model, as improvement, described condensate water partial circulating arm 24 flows to along condensate water and be provided with condensate water partial circulating arm back-water valve (BWV) 18 after condensate water partial circulating arm pressurization cycle pump 19, described condensate water partial circulating arm 24 is between condensate water partial circulating arm back-water valve (BWV) 18 and condensate water partial circulating arm steam heater 22, being connected to by condensate water partial circulating shunt valve flows on the condensate water circulating water main 12 before described condensate water systemic circulation shunt valve and condensate water circulating water main 12 tie point along condensate water, described condensate water partial circulating shunt valve is provided with condensate water partial circulating bypass valve 13.
Be further used as improvement, described condensate water circulating water main 12 flows to before described condensate water systemic circulation shunt valve and condensate water circulating water main 12 tie point along condensate water, is connected with the position of condensate water systemic circulation arm 9 after the condensate water of empty prognosis gas cooler 7 exports by empty cigarette heat exchanger condensate recirculating water pipe; Described empty cigarette heat exchanger condensate recirculating water pipe sets gradually sky cigarette heat exchanger condensate water recirculation pump and empty cigarette heat exchanger condensate water recirculation control valve 10.
Further, as improvement, the condensate water partial circulating arm control valve 1 on condensate water partial circulating arm 24 and position between condensate water partial circulating arm steam heater 22, be provided with condensate water partial circulating arm water cooler 23; And, before described condensate water partial circulating arm water cooler 23 is arranged on the pre-front air heater 2 in air duct 25 overhead, first air by passing through condensate water partial circulating arm water cooler 23, to cool the condensing water temperature in condensate water partial circulating arm 24 further before empty pre-front air heater 2.
As improvement, condensate water circulating water main 12 with empty cigarette heat exchanger condensate recirculating water pipe tie point before be provided with condensate water recirculated water high temperature feed water valve 14; Optional position on condensate water partial circulating arm 24 between condensate water partial circulating arm control valve 1 and condensate water partial circulating arm pressurization cycle pump 19 can be provided with condensate water partial circulating arm back-water valve (BWV) 18; Condensate water partial circulating arm 24 next-door neighbour described condensate water partial circulating arm back-water valve (BWV) 18 before and condensate water circulating water main 12 between condensate water systemic circulation pump 11 and condensate water recirculated water high temperature feed water valve 14, connected by condensate water partial circulating shunt valve, described condensate water partial circulating shunt valve is provided with condensate water partial circulating bypass valve 13.
As improvement, condensate water house steward 20 is between high-temperature level low-pressure heater 15 and low-temperature level low-pressure heater 17, be connected with condensate water circulating water main 12 condensate water recirculated water between condensate water systemic circulation pump 11 and condensate water recirculated water high temperature feed water valve 14 by condensate water recirculated water low temperature supplying water pipe, described condensate water recirculated water low temperature supplying water pipe is provided with condensate water recirculated water low temperature supplying water valve 16.
As improvement, condensate water circulating water main 12 before sky is pre-before air heater 2 (along condensate water flow direction) external hot water feeding pipe can be set, before sky is pre-, air heater 2 arranges external hot water return pipe before condensate water partial circulating arm control valve 1 and condensate water systemic circulation arm control valve 3 afterwards simultaneously.External hot water line can be used as the heat source that unit starting adds hot-air.
The position of the utility model condensate water circulating water main 12 before condensate water systemic circulation pump 11 (along condensate water flow direction) also can be connected with the return pipe of other heat release heat exchangers such as flue gas heater after heat supply network or desulfurizing tower, the position of condensate water systemic circulation arm 9 after empty prognosis gas cooler 7 is connected with the feed pipe of other heat release heat exchangers such as flue gas heater after heat supply network or desulfurizing tower, and such system thermal also can be used for external equipment heat supply.
The method of work of the utility model system comprises:
Flow through the condensate water in the condensate water circulating water main 12 of empty pre-front air heater 2 and the air heat-exchange in air duct 25, condensate water transfers heat to air, and condensing water temperature reduces, and air themperature raises; The condensate water flowed through after empty pre-front air heater 2 enters in condensate water systemic circulation arm 9 and in condensate water partial circulating arm 24 respectively.
When high-temperature flue gas in exhaust gases passes 26 flows through air preheater 8, with flow through in air duct 25 empty pre-before air heater 2 entered the air heat-exchange of air preheater 8 after heating, flue-gas temperature is reduced, and air themperature improves further.
When flue gas after described air preheater 8 in exhaust gases passes 26 flows through sky prognosis gas cooler 7, transfer heat to the condensate water flowing through sky prognosis gas cooler 7 in condensate water systemic circulation arm 9, flue-gas temperature is reduced further, condensing water temperature improves; The condensate water absorbing the temperature of fume afterheat higher gets back to condensate water house steward 20 high temperature section or therrmodynamic system miscellaneous equipment through condensate water systemic circulation arm 9, is utilized by fume afterheat.
Condensate water in condensate water partial circulating arm 24 gets back to the condensate water house steward 20 of therrmodynamic system, mix with condensate water in condensate water house steward 20, flow through successively low-temperature level low-pressure heater 17 and high-temperature level low-pressure heater 15 heat by extracted steam from turbine, a described part by the condensate water after heating enters again condensate water circulating water main 12, starts new heat transfer cycle.
As previously mentioned, the condensate water in condensate water partial circulating arm 24 carries out partial circulating through shorter system path; Condensate water in condensate water systemic circulation arm 9, through Steam Turbine Regenerative System, is finally got back to again in condensate water house steward 20 after successively entering boiler heat absorption and steam turbine acting, is completed systemic circulation.
Or the condensate water in condensate water partial circulating arm 24 is after recirculated water spray header enters turbine low pressure cylinder steam drain, or the condensate water in condensate water partial circulating arm 24 enters the vapour side of low-temperature level low-pressure heater 17 through recirculated water spray header.
After in described recirculated water spray header, the spout atomization of condensate water through connecting enters turbine low pressure cylinder steam drain, with turbine discharge mixed heat transfer, part turbine discharge is condensed into condensate water, decrease the heat directly being taken away discharge by low-temperature receiver, and increase turbine discharge vacuum, improve efficiency of thermal cycle; Mixed condensate water enters the low-pressure heater heat regenerative system of condensate water house steward 20 and series connection through steam turbine condensate pump;
In described recirculated water spray header, the spout atomization of condensate water through connecting enters the vapour side of low-temperature level low-pressure heater 17, with the extracted steam from turbine mixed heat transfer entered in described low-temperature level low-pressure heater 17 vapour side, part extracted steam from turbine is condensed into condensate water, thus increase the extraction flow of steam entering low-temperature level low-pressure heater 17 vapour side, add generated energy, decrease cold source energy, improve effectiveness of regenerator; Mixed condensate water enters the low-pressure heater heat regenerative system of condensate water house steward 20 and series connection through draining system and steam turbine condensate pump.
Condensate water partial circulating arm control valve 1 controls its aperture according to the measured value of air preheater inlet air temperature sensor 4 and gas cooler exit gas temperature sensor 21.
When the air temperature value measured by air preheater inlet air temperature sensor 4 is lower than air preheater entering air temperature setting one value, the aperture of condensate water partial circulating arm control valve 1 increases, to increase the condensing water flow flowed through in empty pre-front air heater 2, increase air heat amount, improve air preheater entering air temperature, eliminate or reduce and deviation that described setting one is worth; Vice versa.
Due to heat transfer temperature difference and the thermally equilibrated change of air preheater 8 and empty prognosis gas cooler 7, air preheater entering air temperature improves can corresponding raising gas cooler exit gas temperature; When the flue-gas temperature value measured by gas cooler exit gas temperature sensor 21 is higher than gas cooler exit gas temperature setting two-value, the aperture of condensate water partial circulating arm control valve 1 reduces, to reduce air heat amount, reduce air preheater entering air temperature, eliminate or reduce the deviation of gas cooler exit gas temperature and described setting two-value; Vice versa.
Condensate water systemic circulation bypass valve 5 controls its aperture according to the measured value of gas cooler exit gas temperature sensor 21 and gas cooler inlet water temperature sensor 6.
When the flue-gas temperature value measured by gas cooler exit gas temperature sensor 21 is higher than gas cooler exit gas temperature setting one value, the aperture of condensate water systemic circulation bypass valve 5 increases, to increase the flow that condensate water flows through sky prognosis gas cooler 7, eliminate or reduce the deviation that gas cooler exit gas temperature and described setting one are worth; Vice versa.
When the condensate water water temperature value measured by gas cooler inlet water temperature sensor 6 is lower than gas cooler inlet water temperature setting two-value, the aperture of condensate water systemic circulation bypass valve 5 increases, to increase the flow being mixed into the higher condensate water of temperature of sky prognosis gas cooler 7, improve gas cooler inlet water temperature, the deviation of elimination or reduction and described setting two-value; Vice versa.
Condensate water systemic circulation arm control valve 3 controls its aperture according to the measured value of gas cooler inlet water temperature sensor 6 and air preheater inlet air temperature sensor 4.
When the condensate water water temperature value measured by gas cooler inlet water temperature sensor 6 is lower than gas cooler inlet water temperature setting one value, the aperture of condensate water systemic circulation arm control valve 3 reduces, the flow of temperature compared with low coagulation water of sky prognosis gas cooler 7 is mixed into minimizing, improve gas cooler inlet water temperature, eliminate or reduce and deviation that described setting one is worth; Vice versa.
When the air temperature value measured by air preheater inlet air temperature sensor 4 is lower than air preheater entering air temperature setting three value, the aperture of condensate water systemic circulation arm control valve 3 increases, to increase the condensing water flow flowed through in empty pre-front air heater 2, increase air heat amount, improve air preheater entering air temperature, eliminate or reduce and deviation that described setting three is worth; Vice versa.
Empty cigarette heat exchanger condensate water recirculation control valve 10 controls its aperture according to the measured value of gas cooler inlet water temperature sensor 6 and air preheater inlet air temperature sensor 4.
When the condensate water water temperature value measured by gas cooler inlet water temperature sensor 6 is lower than gas cooler inlet water temperature setting three value, the aperture of empty cigarette heat exchanger condensate water recirculation control valve 10 increases, to increase the flow being mixed into the higher condensate water of temperature of sky prognosis gas cooler 7, improve gas cooler inlet water temperature, eliminate or reduce and deviation that described setting three is worth; Vice versa.
When the air temperature value measured by air preheater inlet air temperature sensor 4 is lower than air preheater entering air temperature setting two-value, the aperture of empty cigarette heat exchanger condensate water recirculation control valve 10 increases, to increase the condensate water water temperature be mixed in empty pre-front air heater 2, increase air heat amount, improve air preheater entering air temperature, the deviation of elimination or reduction and described setting two-value; Vice versa.
Condensate water systemic circulation pump 11 is temperature optimization controlling run frequency measured by air preheater inlet air temperature sensor 4, gas cooler inlet water temperature sensor 6 and gas cooler exit gas temperature sensor 21 mainly.Temperature (being worth lower than respective setting one) on the low side measured by air preheater inlet air temperature sensor 4, the gas cooler inlet water temperature sensor 6, or measured by gas cooler exit gas temperature sensor 21 during temperature drift (higher than its setting one value), improve condensate water systemic circulation pump 11 running frequency to strengthen the circulation of condensate water; Vice versa.When condensate water systemic circulation pump 11 installation site is before empty cigarette heat exchanger condensate water recirculation control valve 10, the running frequency of condensate water systemic circulation pump 11 does not control by gas cooler exit gas temperature sensor 21 measuring tempeature.
When temperature measured by gas cooler inlet water temperature sensor 6 is lower than gas cooler inlet water temperature protection value; or when temperature measured by gas cooler exit gas temperature sensor 21 is lower than gas cooler exit gas temperature protection value; condensate water systemic circulation pump 11 is forced to stop transport, and to avoid the heat exchange of sky prognosis gas cooler 7, serious cold end corrosion and stifled ash occurs.
Condensate water partial circulating arm pressurization cycle pump 19 is temperature optimization controlling run frequency measured by air preheater inlet air temperature sensor 4 and gas cooler exit gas temperature sensor 21 mainly.(be worth lower than respective setting one) when temperature is on the low side measured by air preheater inlet air temperature sensor 4, gas cooler exit gas temperature sensor 21, improve condensate water partial circulating arm pressurization cycle pump 19 running frequency to strengthen the circulation of partial circulating arm condensate water; Vice versa.
Described air preheater entering air temperature setting one value is more than or equal to air preheater entering air temperature setting two-value, and air preheater entering air temperature setting two-value is more than or equal to air preheater entering air temperature and sets three values; Described air preheater entering air temperature setting one value is between 0 ~ 100 DEG C.The described difference range be respectively more than or equal to is between 0 ~ 20 DEG C.
Described gas cooler exit gas temperature protection value is less than gas cooler exit gas temperature and sets a value, and gas cooler exit gas temperature setting one value is less than or equal to gas cooler exit gas temperature setting two-value; Described gas cooler exit gas temperature protection value lower than flue gas acid dew point 50 DEG C between higher than flue gas acid dew point 20 DEG C; Described gas cooler exit gas temperature setting one value lower than flue gas acid dew point 40 DEG C between higher than flue gas acid dew point 25 DEG C; The described difference range be respectively less than or equal to is between 0 ~ 20 DEG C.
Described gas cooler inlet water temperature setting one value is more than or equal to gas cooler inlet water temperature setting two-value; gas cooler inlet water temperature setting two-value is more than or equal to gas cooler inlet water temperature and sets three values, and gas cooler inlet water temperature setting three values are more than or equal to gas cooler inlet water temperature protection value.Described gas cooler inlet water temperature protection value lower than flue gas acid dew point 60 DEG C between higher than flue gas acid dew point 15 DEG C.The described difference range be respectively more than or equal to is between 0 ~ 20 DEG C.
The aperture of condensate water partial circulating bypass valve 13, condensate water recirculated water high temperature feed water valve 14, condensate water recirculated water low temperature supplying water valve 16, condensate water partial circulating arm back-water valve (BWV) 18 regulates and cooperatively interacts, and can be used for regulating condensation water temperature in condensate water circulating water main 12.
Open large condensate water partial circulating bypass valve 13 aperture, turn down condensate water partial circulating arm back-water valve (BWV) 18 aperture, condensation water temperature in condensate water circulating water main 12 can be reduced, thus the heat exchange of the empty prognosis gas cooler 7 of auxiliary adjustment and the pre-front air heater 2 of sky.Vice versa.
Increase condensate water recirculated water high temperature feed water valve 14 aperture, turns down condensate water recirculated water low temperature supplying water valve 16 aperture, can promote condensation water temperature in condensate water circulating water main 12, thus the heat exchange of the empty prognosis gas cooler 7 of auxiliary adjustment and the pre-front air heater 2 of sky.Vice versa.
As improvement, the aperture of condensate water systemic circulation bypass valve 5 can be controlled according to the temperature value of gas cooler outlet cooling-water temperature sensor measurement, to regulate the condensing water flow in condensate water systemic circulation arm 9; When the temperature value that gas cooler outlet cooling-water temperature sensor is measured is lower than setting value, then the corresponding aperture turning down condensate water systemic circulation bypass valve 5.Vice versa.
By arranging condensate water partial circulating arm steam heater 22, the utility model also can not need partial circulating arm booster pump, the recirculated water of condensate water partial circulating arm is got back to condensate water circulating water main 12 by condensate water partial circulating bypass valve 13, complete utilize low parameter draw gas heating low-temperature condensate partial circulating.
Air preheater entering air temperature increases, and can improve air preheater exit gas temperature and heat-transfer surface wall temperature, is conducive to preventing the cold end corrosion of air preheater 8 and stifled ash; Air preheater entering air temperature is improved by condensate water partial circulating, also can Appropriate application low temperature cold source resource, reduce steam turbine steam discharge heat loss, improve steam turbine steam discharge vacuum, increase the extraction cycle thermal efficiency.But air preheater entering air temperature increases, can exhaust gas temperature be improved simultaneously, be unfavorable for the raising of system effectiveness; Vice versa.
Gas cooler inlet water temperature and gas cooler exit gas temperature increase, and can improve gas cooler heat-transfer surface wall temperature, are conducive to preventing the cold end corrosion of sky prognosis gas cooler 7 and stifled ash, but can improve exhaust gas temperature, are unfavorable for the raising of system effectiveness; Vice versa.
In addition, the utility model can quote amount of sulfur contenting in smoke or the flue gas acid dew point measured value of monitoring in real time, the initial set value such as auto modification gas cooler inlet water temperature, gas cooler exit gas temperature and air preheater entering air temperature, to strengthen unit to the adaptability using coal and equipment operation condition.When amount of sulfur contenting in smoke or flue gas acid dew point measured value increase than initial set value, this deviation exports each correction value through control algorithm, to increase each setting value of gas cooler inlet water temperature, gas cooler exit gas temperature and air preheater entering air temperature respectively; Vice versa.
It should be noted last that, above embodiment is only in order to illustrate the technical solution of the utility model and unrestricted.Although be described in detail the utility model with reference to embodiment, those of ordinary skill in the art is to be understood that, the technical solution of the utility model is modified or equivalent replacement, do not depart from the spirit and scope of technical solutions of the utility model, it all should be encompassed in the middle of right of the present utility model.

Claims (8)

1. an adjustable boiler air preheating system for comprehensive backheat and UTILIZATION OF VESIDUAL HEAT IN, comprising: air preheater (8), air duct (25) and exhaust gases passes (26), and it is characterized in that, described system also comprises:
Empty pre-front air heater (2), empty prognosis gas cooler (7), condensate water systemic circulation arm (9), condensate water circulating water main (12), condensate water house steward (20), condensate water partial circulating arm (24), low-temperature level low-pressure heater (17) and high-temperature level low-pressure heater (15);
Described air duct (25) is all connected with described air preheater (8) with exhaust gases passes (26);
Before described sky is pre-, air heater (2) is arranged on the front air duct (25) of air preheater (8) along air flow; Described empty prognosis gas cooler (7) is arranged on the exhaust gases passes (26) after air preheater (8) along flue gas flow direction;
Described low-temperature level low-pressure heater (17) and high-temperature level low-pressure heater (15) flow to be connected successively along condensate water and are arranged on condensate water house steward (20);
Before described sky is pre-, the inlet tube of the condensate water of air heater (2) is connected with condensate water circulating water main (12), and condensate water circulating water main (12) other end is connected on the condensate water house steward (20) that high-temperature level low-pressure heater (15) exports, before described sky is pre-, the condensate water outlet of air heater (2) is divided into two-way, one tunnel is condensate water systemic circulation arm (9), the other end of described condensate water systemic circulation arm (9) is connected to pressure lower than condensate water house steward (20) with on the therrmodynamic system miscellaneous equipment of the pressure of condensate water circulating water main (12) tie point, or, the other end of described condensate water systemic circulation arm (9) and the tie point of condensate water house steward (20) are along after condensate water flows to the tie point being positioned at condensate water circulating water main (12) and condensate water house steward (20), another road is condensate water partial circulating arm (24), and condensate water partial circulating arm (24) other end is connected with the condensate water house steward (20) of low-temperature level low-pressure heater (17) entrance, the condensate water inlet tube of described empty prognosis gas cooler (7) and outlet flow to along condensate water respectively and are connected on condensate water systemic circulation arm (9),
Described system also comprises: condensate water partial circulating arm control valve (1), condensate water systemic circulation arm control valve (3) and condensate water systemic circulation bypass valve (5);
Described condensate water partial circulating arm control valve (1) is arranged on condensate water partial circulating arm (24), and described condensate water systemic circulation arm control valve (3) is arranged on condensate water systemic circulation arm (9) empty prognosis gas cooler (7) is front;
Before the inlet tube of described condensate water circulating water main (12) condensate water of air heater (2) before sky is pre-, be connected between condensate water systemic circulation arm control valve (3) and empty prognosis gas cooler (7) with condensate water systemic circulation arm (9) by condensate water systemic circulation shunt valve, described condensate water systemic circulation shunt valve is provided with condensate water systemic circulation bypass valve (5);
Described condensate water partial circulating arm (24) flows to condensate water partial circulating arm pressurization cycle pump (19) being provided with variable ratio frequency changer and regulating after condensate water partial circulating arm control valve (1) along condensate water.
2. system according to claim 1, is characterized in that, described exhaust gases passes (26) is provided with gas cooler exit gas temperature sensor (21) after empty prognosis gas cooler (7); Described air duct (25) is provided with air preheater inlet air temperature sensor (4) between air heater (2) and air preheater (8) before sky is pre-; On described condensate water systemic circulation arm (9) between empty prognosis gas cooler (7) and the tie point of condensate water systemic circulation shunt valve and condensate water systemic circulation arm (9), be provided with gas cooler inlet water temperature sensor (6); Described condensate water systemic circulation arm (9) is provided with after empty prognosis gas cooler (7) gas cooler outlet cooling-water temperature sensor.
3. system according to claim 1, it is characterized in that, described condensate water circulating water main (12) is provided with the condensate water systemic circulation pump (11) that variable ratio frequency changer regulates before described condensate water systemic circulation shunt valve and condensate water circulating water main (12) tie point; Described condensate water circulating water main (12) is connected with the position of condensate water systemic circulation arm (9) after the condensate water of empty prognosis gas cooler (7) exports by empty cigarette heat exchanger condensate recirculating water pipe before the condensate water entrance of condensate water systemic circulation pump (11), described empty cigarette heat exchanger condensate recirculating water pipe is arranged and is free cigarette heat exchanger condensate water to recycle control valve (10).
4. system according to claim 1, it is characterized in that, described condensate water partial circulating arm (24) is provided with condensate water partial circulating arm steam heater (22) between condensate water partial circulating arm control valve (1) and condensate water partial circulating arm pressurization cycle pump (19).
5. system according to claim 1, it is characterized in that, location arrangements condensate water systemic circulation pump (11) between condensate water systemic circulation arm (9) overhead prognosis gas cooler (7) and the tie point of condensate water systemic circulation shunt valve and condensate water systemic circulation arm (9).
6. system according to claim 1, it is characterized in that, described condensate water partial circulating arm (24) is connected with recirculated water spray header between condensate water partial circulating arm control valve (1) and condensate water partial circulating arm pressurization cycle pump (19), after the other end of described recirculated water spray header is connected to the turbine low pressure cylinder steam drain along vapor flow direction, or the other end of described recirculated water spray header is connected to the vapour side of low-temperature level low-pressure heater (17).
7. the system according to claim 1 or 4, it is characterized in that, described condensate water partial circulating arm (24) flows to along condensate water and be provided with condensate water partial circulating arm back-water valve (BWV) (18) after condensate water partial circulating arm pressurization cycle pump (19), described condensate water partial circulating arm (24) is between condensate water partial circulating arm back-water valve (BWV) (18) and condensate water partial circulating arm steam heater (22), being connected to by condensate water partial circulating shunt valve flows on the condensate water circulating water main (12) before described condensate water systemic circulation shunt valve and condensate water circulating water main (12) tie point along condensate water, described condensate water partial circulating shunt valve is provided with condensate water partial circulating bypass valve (13).
8. system according to claim 7, it is characterized in that, described condensate water circulating water main (12) flows to before described condensate water systemic circulation shunt valve and condensate water circulating water main (12) tie point along condensate water, is connected with the position of condensate water systemic circulation arm (9) after the condensate water of empty prognosis gas cooler (7) exports by empty cigarette heat exchanger condensate recirculating water pipe; Described empty cigarette heat exchanger condensate recirculating water pipe sets gradually sky cigarette heat exchanger condensate water recirculation pump and empty cigarette heat exchanger condensate water recirculation control valve (10).
CN201520722976.XU 2015-09-17 2015-09-17 Synthesize backheat and waste heat utilization's adjustable boiler preheating of air system Withdrawn - After Issue CN204987074U (en)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105091020A (en) * 2015-09-17 2015-11-25 郝江平 Adjustable boiler air preheating system and method integrating heat regeneration and waste heat utilization
CN105864811A (en) * 2016-04-07 2016-08-17 山东中科洁能科技有限公司 Pulverized coal milling device and method
CN106439899A (en) * 2016-08-31 2017-02-22 中国大唐集团科学技术研究院有限公司 Air cooling unit steam turbine waste heat using system and method
CN113063161A (en) * 2021-04-16 2021-07-02 国家电投集团重庆合川发电有限公司 Boiler flue gas waste heat recovery system of thermal power factory

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105091020A (en) * 2015-09-17 2015-11-25 郝江平 Adjustable boiler air preheating system and method integrating heat regeneration and waste heat utilization
CN105091020B (en) * 2015-09-17 2017-04-12 郝江平 Adjustable boiler air preheating system and method integrating heat regeneration and waste heat utilization
CN105864811A (en) * 2016-04-07 2016-08-17 山东中科洁能科技有限公司 Pulverized coal milling device and method
CN105864811B (en) * 2016-04-07 2017-05-03 山东中科洁能科技有限公司 Pulverized coal milling device and method
CN106439899A (en) * 2016-08-31 2017-02-22 中国大唐集团科学技术研究院有限公司 Air cooling unit steam turbine waste heat using system and method
CN113063161A (en) * 2021-04-16 2021-07-02 国家电投集团重庆合川发电有限公司 Boiler flue gas waste heat recovery system of thermal power factory

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