CN105333450A

CN105333450A - Comprehensive gradient utilization system of recovered heat and waste heat of thermal power generation

Info

Publication number: CN105333450A
Application number: CN201510824264.3A
Authority: CN
Inventors: 郝江平
Original assignee: Individual
Current assignee: Individual
Priority date: 2015-11-24
Filing date: 2015-11-24
Publication date: 2016-02-17
Anticipated expiration: 2035-11-24
Also published as: CN105333450B

Abstract

The invention relates to a comprehensive gradient utilization system of recovered heat and waste heat of thermal power generation. The comprehensive gradient utilization system comprises an air pre-heater subsystem, a main condensation water subsystem, a medium temperature condensation water supply subsystem, a low temperature condensation water supply subsystem, a smoke cooling condensation water subsystem and an air heating condensation water subsystem. The air pre-heater subsystem is connected with the smoke cooling condensation water subsystem, the medium temperature condensation water supply subsystem, the low temperature condensation water supply subsystem and the air heating condensation water subsystem and then is connected to the main condensation water subsystem in a collected mode.

Description

A kind of backheat of thermal power generation, the system of residual heat integrative cascade utilization

Technical field

The present invention relates to thermal power generation technical field, particularly a kind of backheat of thermal power generation, the system of residual heat integrative cascade utilization.

Background technology

In heat power generating system, backheat mode is adopted to be improve the important means of circulation system efficiency.According to the extraction cycle of extracted steam from turbine heat-setting water and feedwater, can reduce the cold source energy of turbine discharge on the one hand, heat regenerative system can improve the feed temperature of boiler on the other hand, thus reduce irreversibility that the boiler heat-transfer temperature difference produces and loss.The raising of feed temperature too increases the flue-gas temperature after heated feed water, and the higher flue gas of this temperature adopts the mode of backheat to enter the combustion air of boiler with preheating by air preheater usually, can reduce to heat into stove cold air process loss, reduces exhaust gas temperature, reduces smoke discharging residual heat loss, also contributes to the normal operation of boiler milling system and combustion system and the raising of boiler combustion efficiency simultaneously.

Boiler feed temperature and draw gas certain with the mean temperature difference that feeds water, and total turbine discharge amount constant when, in carbonated drink backheat, the steam turbine low parameter amount of drawing gas is larger, the high parameter amount of drawing gas is less, then the generated energy of unit working medium is more, and efficiency of thermal cycle is higher.Due to the restriction by bleeder heater vapour, water side import and export parameter, the more senior amount of drawing gas of steam turbine can not be too little, and the more rudimentary 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.Reduce cigarette temperature and can improve system thermal efficiency, but more easily make heat-transfer surface generation cold end corrosion, cause serious stifled ash simultaneously, again reduce heat transfer efficiency.Otherwise, if improve exhaust gas temperature, although the harm of cold end corrosion and stifled ash can be alleviated, system thermal efficiency reduces.At present, mainly adopt rotation heat accumulating type air preheater, its heat exchanger cold junction heat-transfer surface wall temperature is far below wall temperature mean value before entering fume side by air side, even if adopt higher exhaust gas temperature, cold junction heat-transfer surface still exists the problem of cold end corrosion and stifled ash.In addition, boiler SCR flue gas denitrification system can improve flue gas acid dew point, and the hydrogen sulfate ammonia (NH) after denitration in flue gas ₄hSO ₄, the stifled ash of caking property of air preheater cold-end air can be aggravated.

Traditional air preheater adopts fixing design parameter according to design conditions, and exhaust gas temperature is constantly changed with changes such as environment temperature, combustion position and boiler operating parameters.In order to avoid the stifled ash of air preheater affects unit safety operation, existing air preheater can only increase the design load of exhaust gas temperature.The feed temperature of modern large-sized unit is higher, and empty pre-inlet flue gas temperature is higher, and limit by the gentle thermal balance of heat primary air, exhaust gas temperature is also higher.In addition, the design of the air themperature of air preheater outlet need meet the demand of combustion system, and the exhaust gas temperature of unburnable coal design is also often a lot of higher than flue gas acid dew point, causes very large fume afterheat loss.

The design of steam air heater can meet northern area and heat air preheater intake air needs winter, improves device security, and has 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, capacity for work, 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 it is thrown and stops controlling and can not conform temperature and the frequent of flue-gas temperature of regulating power significantly changes, and is subject to steam and water bursting and thermal shock and faults frequent.

Existing most heat recovery technology mainly considers reduction exhaust gas temperature, can not solve the coupled problem of the safety and efficiency of conventional air preheater.During winter, because air temperature is lower, after air preheater, exhaust gas temperature is also lower, and the rate that comes into operation of gas cooler is very low.Existing most heat recovery technology does not combine with unit heat regenerative system yet, often only notice the temperature promoting and reclaim low temperature exhaust heat, and ignore the utilization of low temperature cold source, do not carry out the optimizing regulation of low-grade utility, realize the cascade utilization of energy.

High-low pressure two-stage is divided by smoke gas afterheat heat exchanger to be placed in air preheater bypass flue, although the controllability of UTILIZATION OF VESIDUAL HEAT IN can be improved, but its system and operation control complicated, and spatial placement large flue sharp turn head less before and after air preheater, make the flow field uniformity of heat exchanger poor, heat exchange, stifled ash and wear condition all worsen.In addition, although its hiigh pressure stage UTILIZATION OF VESIDUAL HEAT IN thermal efficiency is higher, walks air preheater bypass due to partial fume and can change the former thermal balance of air preheater, reduce empty pre-outlet air temperature and boiler efficiency, increase the mean temperature difference of flue gas and other working medium, irreversible entropy produce and loss increases, and the overall efficiency of thermodynamic cycle declines.

At present, the waste heat of turbine discharge and low-temperature receiver utilize general not good.Due to winter, the heating efficiency of heat pump is lower, and when Absorption of Medium steam turbine exhausted spare heat reaches required heat supply temperature, it is outer excessive for high-quality energy that heat pump consumes, and causes system economy poor.Air-cooled Unit steam discharge vacuum is lower, and summer, steam discharge parameter was even up to more than 30KPa, and the impact of Direct Air-Cooling Technology also by ambient wind is very large, and high back pressure runs and not only has a strong impact on exerting oneself of unit, but also threatens the security of operation of unit.Some Air-cooled Unit adopt various spike cooling system, gas clean-up at about 2 ~ 5KPa, but investment or operating cost higher, economy is not good.

Summary of the invention

The object of the invention is to, in order to solve, existing thermal power generator boiler smoke air backheating (air preheat) is not enough, boiler circuit backheat (feedwater heating) is not enough and residual heat from boiler fume and the low problem of steam turbine exhausted spare heat recovery utilization rate, the invention provides the system of a kind of backheat of thermal power generation, residual heat integrative cascade utilization.

The invention provides the system of a kind of backheat of thermal power generation, residual heat integrative cascade utilization, this system comprises: in air preheater subsystem, main condensate subsystem, condensate water, temperature is for water subsystem, condensate water low temperature supplying water subsystem, flue gas cooling condensate water subsystem and air heat condensate water subsystem; Described air preheater subsystem to connect in described flue gas cooling condensate water subsystem, described condensate water temperature respectively for water subsystem, described condensate water low temperature supplying water subsystem and described air heat condensate water subsystem, then gathers and be connected with described main condensate subsystem.

Described air preheater subsystem comprises: air preheater 11, air duct 29, exhaust gases passes 30, empty pre-front air heater 4, air preheater inlet air temperature sensor 5;

Described air duct 29 is all connected with described air preheater 11 with described exhaust gases passes 30; Before described sky is pre-, air heater 4 is arranged on the described air duct 29 before described air preheater 11 along air flow;

Described air preheater inlet air temperature sensor 5 is arranged on the pre-front described air duct 29 between air heater 4 and described air preheater 11 of described sky;

Described flue gas cooling condensate water subsystem comprises: flue gas cooling condensate water arm 8, gas cooler condensate water manifold valve 32, flue gas cooling condensate water arm increases circulating pump 31, gas cooler inlet water temperature sensor 9, empty prognosis gas cooler 3, gas cooler exit gas temperature sensor 13 and gas cooler outlet cooling-water temperature sensor 12;

Described gas cooler condensate water manifold valve 32, described flue gas cooling condensate water arm increases circulating pump 31, described gas cooler inlet water temperature sensor 9, described empty prognosis gas cooler 3 and described gas cooler outlet cooling-water temperature sensor 12 flow to along condensate water and are successively set on described flue gas cooling condensate water arm 8;

Described gas cooler exit gas temperature sensor 13 is arranged on the described exhaust gases passes 30 after described empty prognosis gas cooler 3 along flue gas flow direction;

Described main condensate subsystem comprises: condensate water supervisor 20, main condensate control valve 16, middle temperature level low-pressure heater 18 and low-temperature level low-pressure heater 21;

Described main condensate control valve 16, described middle temperature level low-pressure heater 18 and described low-temperature level low-pressure heater 21 flow to along condensate water and are successively set on described condensate water supervisor 20;

In described condensate water, temperature comprises for water subsystem: warm water main 14 in condensate water;

Described condensate water low temperature supplying water subsystem comprises: condensate water low temperature supplying supply mains 15, air heat condensate water control valve 6, flue gas cooling low-temperature condensate arm and flue gas cooling cryogenic temperature condensation water regulating valve 19;

Described air heat condensate water control valve 6 is arranged on described condensate water low temperature supplying supply mains 15; Before one end of described flue gas cooling low-temperature condensate arm is connected to the air heat condensate water control valve 6 that condensate water low temperature supplying supply mains 15 flows to along condensate water; The other end of described flue gas cooling low-temperature condensate arm is connected on the described flue gas cooling condensate water arm 8 between described flue gas cooling condensate water arm pressurization cycle pump 31 and described gas cooler condensate water manifold valve 32; Described flue gas cooling low-temperature condensate arm is provided with described flue gas cooling low-temperature condensate arm control valve 19;

Described air heat condensate water subsystem comprises: air heat condensate water arm 2, warm condensate water control valve 7 in air heat, low-temperature condensate loop branch pipe booster pump 26, low-temperature condensate loop branch pipe non-return valve 25, low-temperature condensate loop branch pipe valve 24, cryogenic temperature condensation Water spray arm and low-temperature condensate shower valve 28;

Warm condensate water control valve 7 in described air heat, described low-temperature condensate loop branch pipe booster pump 26, described low-temperature condensate loop branch pipe non-return valve 25, described low-temperature condensate loop branch pipe valve 24 flows to according to condensate water and is successively set on described air heat condensate water arm 2;

Condensate water on described air heat condensate water arm 2 flows through warm condensate water control valve 7 in described air heat successively, air heater 4 before described sky is pre-, described low-temperature condensate loop branch pipe booster pump 26, described low-temperature condensate loop branch pipe non-return valve 25, described low-temperature condensate loop branch pipe valve 24;

One end of described cryogenic temperature condensation Water spray arm be connected to described sky pre-before on described air heat condensate water arm 2 between air heater 4 and described low-temperature condensate loop branch pipe booster pump 26, after its other end is connected to the turbine low pressure cylinder steam drain along vapor flow direction;

Described cryogenic temperature condensation Water spray arm flows to along condensate water and is provided with described low-temperature condensate shower valve 28 and atomizing sprayer successively;

One end of described flue gas cooling condensate water arm 8 is connected to and flows on the described condensate water supervisor 20 after described main condensate control valve 16 along condensate water, and its other end is connected to the one end of warm water main 14 in described condensate water;

One end of described air heat condensate water arm 2 is connected to and flows on the described condensate water supervisor 20 before described low-temperature level low-pressure heater 21 along condensate water, and the other end is connected to the one end of warm water main 14 in described condensate water;

In described condensate water, two-way is divided in one end of warm water main 14, one end that one tunnel cools condensate water arm 8 with described flue gas is connected, another road is connected with one end of described air heat condensate water arm 2, and in described condensate water, the other end of warm water main 14 is connected on the described condensate water supervisor 20 between described main condensate control valve 16 and described middle temperature level low-pressure heater 18;

One end of described condensate water low temperature supplying supply mains 15 is connected on the described air heat condensate water arm 2 in the pre-front air heater 4 of described sky and described air heat between warm condensate water control valve 7; The other end is connected on the described condensate water supervisor 20 between described low-temperature level low-pressure heater 21 and described middle temperature level low-pressure heater 18.

As the further improvement of technical scheme, described air heat condensate water subsystem also comprises: empty pre-front Cryogenic air heater 4a and air heater outlet cooling-water temperature sensor 1;

The pre-front Cryogenic air heater 4a of described sky is arranged on the described air duct 29 before the pre-front air heater 4 of described sky;

Described air heater outlet cooling-water temperature sensor 1 is arranged on the described air heat condensate water arm 2 after the pre-front Cryogenic air heater 4a of described sky.

Described condensate water low temperature supplying water subsystem also comprises empty pre-front Cryogenic air heat-setting water arm and the pre-front Cryogenic air heat-setting water regulating valve 23 of sky;

Before before described sky is pre-, one end of Cryogenic air heat-setting water arm is connected to the air heat condensate water control valve 6 of condensate water low temperature supplying supply mains 15, the other end be connected to sky on air heat condensate water arm 2 pre-before air heater 4 and sky pre-before between Cryogenic air heater 4a;

The pre-front Cryogenic air heat-setting water regulating valve 23 of described sky is arranged on the pre-front Cryogenic air heat-setting water arm of sky before described air heat condensate water control valve 6.

As the further improvement of technical scheme, described air heat condensate water subsystem also comprises: low-temperature condensate loop branch pipe steam heater 27; Described low-temperature condensate loop branch pipe steam heater 27 is arranged on the described air heat condensate water arm 2 before described low-temperature condensate loop branch pipe booster pump 26.

The heating steam of described low-temperature condensate loop branch pipe steam heater 27 is that steam turbine last stage draws gas or turbine discharge.

As the further improvement of technical scheme, this system also comprises more cryogenic temperature condensation water circulation system; Described more cryogenic temperature condensation water circulation system comprises: cryogenic temperature condensation water recycle arm and cryogenic temperature condensation water recycle control valve 22;

Described cryogenic temperature condensation water recycle arm one end is connected on the described air heat condensate water arm 2 between low-temperature condensate loop branch pipe valve 24 and low-temperature condensate loop branch pipe non-return valve 25, its other end be connected to described sky on described air heat condensate water arm 2 pre-before in air heater 4 and described air heat between warm condensate water control valve 7; Or, its other end be connected to described sky on described air heat condensate water arm 2 pre-before Cryogenic air heater 4a and described sky pre-before between air heater 4;

Described cryogenic temperature condensation water recycle arm is provided with cryogenic temperature condensation water recycle control valve 22.

As the further improvement of technical scheme, described condensate water more low temperature supplying water system also comprises: low-temperature circulating pipe, low-temperature circulating pipe control valve 33, low-temperature circulating isolating valve 34 and more low-temp low-pressure heater 35;

Described low-temperature circulating isolating valve 34 is arranged on the cryogenic temperature condensation water recycle arm before described cryogenic temperature condensation water recycle control valve 22;

The described condensate water that described more low-temp low-pressure heater 35 is arranged between the tie point of described condensate water supervisor 20 and described air heat condensate water arm 2 and described low-temperature level low-pressure heater 21 is responsible on 20;

One end of described low-temperature circulating pipe is connected between described more low-temp low-pressure heater 35 on described condensate water supervisor 20 and described low-temperature level low-pressure heater 21; Its other end is connected between cryogenic temperature condensation water recycle control valve 22 on cryogenic temperature condensation water recycle arm and low-temperature circulating isolating valve 34;

Described low-temperature circulating pipe is provided with low-temperature circulating pipe control valve 33.

As the further improvement of technical scheme, described empty prognosis gas cooler 3 is by empty prognosis high-temperature flue gas cooler 10b, and in empty prognosis, warm gas cooler 10 and empty prognosis low-temperature flue gas cooler 10a tri-part form; And three is connected on described flue gas cooling condensate water arm 8 along the condensate water flow direction successively;

Flue gas cooling condensate water arm 8 in described empty prognosis between warm gas cooler 10 and empty prognosis low-temperature flue gas cooler 10a is connected with low temperature cigarette recirculation of cold water pipe; The other end of described low temperature cigarette recirculation of cold water pipe be connected to warm condensate water control valve 7 and sky in the air heat on air heat condensate water arm 2 pre-before between air heater 4; Described low temperature cigarette recirculation of cold water pipe is provided with low temperature cigarette recirculation of cold water valve 38;

Flue gas cooling condensate water arm 8 in described empty prognosis between warm gas cooler 10 and empty prognosis high-temperature flue gas cooler 10b is connected with middle temperature cigarette recirculation of cold water pipe; The other end of described middle temperature cigarette recirculation of cold water pipe is connected to low temperature cigarette recirculation of cold water valve 38 on described low temperature cigarette recirculation of cold water pipe and low temperature cigarette recirculation of cold water pipe and flue gas and cools between the tie point of condensate water arm 8; Described middle temperature cigarette recirculation of cold water pipe flows to along condensate water and is disposed with the pre-front high-temperature air heater 4b of middle temperature cigarette recirculation of cold water valve 39, middle high temperature cigarette recirculation of cold water pump 42 and sky;

Described middle temperature cigarette recirculation of cold water pipe is connected with high temperature cigarette recirculation of cold water pipe between middle temperature cigarette recirculation of cold water valve 39 and middle high temperature cigarette recirculation of cold water pump 42; After the other end of described high temperature cigarette recirculation of cold water pipe is connected to the gas cooler outlet cooling-water temperature sensor 12 on flue gas cooling condensate water arm 8; Described high temperature cigarette recirculation of cold water pipe flows to along condensate water and is disposed with high temperature cigarette recirculation of cold water booster pump 43 and high temperature cigarette recirculation of cold water valve 40;

Described air heat condensate water subsystem also comprises: empty pre-front high-temperature air heater 4b; Before described sky is pre-, high-temperature air heater 4b is arranged on the described air duct 29 between described air preheater inlet air temperature sensor 5 and the pre-front air heater 4 of described sky.

As the further improvement of technical scheme, after described low temperature cigarette recirculation of cold water valve 38 is opened, partial coagulation current air heater 4 before described sky is pre-in described flue gas cooling condensate water arm 8 in described empty prognosis low-temperature flue gas cooler 10a after heat absorption, directly utilizes part low-temperature flue gas waste heat air heater 4 before described sky is pre-to heat the air in described air duct 29;

Described low temperature cigarette recirculation of cold water valve 38 and described high temperature cigarette recirculation of cold water valve 40 are closed, after described middle temperature cigarette recirculation of cold water valve 39 is opened, the recirculation of warm condensate water in formation, make the partial coagulation current high-temperature air heater 4b before described sky is pre-in the described flue gas cooling condensate water arm 8 in described empty prognosis in warm gas cooler 10 after heat absorption, utilize warm fume afterheat high-temperature air heater 4b before described sky is pre-in part to heat the air in described air duct 29;

Described low temperature cigarette recirculation of cold water valve 38 and described middle temperature cigarette recirculation of cold water valve 39 are closed, after described high temperature cigarette recirculation of cold water valve 40 is opened, form the recirculation of condensed water in high temperature, make the partial coagulation current high-temperature air heater 4b before described sky is pre-in the described flue gas cooling condensate water arm 8 in described empty prognosis high-temperature flue gas cooler 10b after heat absorption, utilize the air of part high-temperature flue gas waste heat before sky is pre-in high-temperature air heater 4b warmed up air passage 29.

As the further improvement of technical scheme, the described condensate water supervisor 20 after described low-temperature condensate shower valve 28 flows to along condensate water and is provided with hydraulic recovery mechanical device 37 successively, leak vacuum protection quick closing valve water-sealed valve 36.

As the further improvement of technical scheme, described air duct 29 is provided with steam heater between described air preheater 11 and described air preheater inlet air temperature sensor 5, to come into operation when environment temperature is lower, guarantee that the air themperature entering described air preheater 11 reaches requirement, and make the exhaust gas temperature after described air preheater 11 reach requirement.

As the further improvement of technical scheme, described main condensate control valve 16 is provided with bypass valve in parallel with it, the metered flow sum of described main condensate control valve 16 and described bypass valve is more than or equal to the metered flow of described condensate water supervisor 20, and the metered flow of described bypass valve is less than the metered flow of described main condensate control valve 16; One of described main condensate control valve 16 and described bypass valve are in full-gear when normal operation, and another valve is in less flow restriction control state, to reduce total restriction loss of condensate water supervisor 20.

As the further improvement of technical scheme, described air duct 29 is provided with tunnel inlet air temperature sensor before Cryogenic air heater 4a before described sky is pre-, so that monitor the difference of its measured value and described air preheater inlet air temperature sensor 5 measured value, corresponding correction if desired adds the aperture of each condensate water control valve of hot-air.

As the further improvement of technical scheme, described flue gas cooling condensate water arm 8 on described condensate water supervisor 20 and described condensate water are responsible between the tie point of 20 and described main condensate control valve 16 and are provided with high-temperature level low-pressure heater 17, improve the benefit of waste heat recovery when condensate water is absorbed heat larger in described empty prognosis gas cooler 3.

As the further improvement of technical scheme, in described condensate water, warm water main 14 is provided with the startup heater 41 of band bypass valve, in unit starting process, condensate water in described condensate water in warm water main 14 flows through described startup heater 41, heats condensate water in described condensate water in warm water main 14 by described startup heater 41 by external source; After unit starting, the bypass valve of described startup heater 41 is opened, and the condensate water in described condensate water in warm water main 14 flows through bypass valve and walks around described startup heater 41, to reduce SR;

As the further improvement of technical scheme, described flue gas cooling condensate water arm 8 is connected with outer supplying hot water pipeline after described gas cooler outlet cooling-water temperature sensor 12, outer supplying hot water pipeline is provided with external heat water lines feed water valve, fume afterheat can be utilized externally to provide heat to make system.

As the further improvement of technical scheme, described air heat condensate water control valve 6 controls its aperture according to the measured value of described air preheater inlet air temperature sensor 5;

When the air temperature value measured by described air preheater inlet air temperature sensor 5 is worth lower than described air preheater entering air temperature setting value first, the aperture of described air heat condensate water control valve 6 increases, with increase condensate water flow through described sky pre-before the flow of air heater 4, eliminate or reduce the deviation that air preheater entering air temperature and described setting value first are worth; Vice versa.

Described flue gas cooling cryogenic temperature condensation water regulating valve 19 controls its aperture according to the measured value of described gas cooler inlet water temperature sensor 9;

When the inlet water temperature value measured by described gas cooler inlet water temperature sensor 9 is lower than gas cooler inlet water temperature setting value, the aperture of described flue gas cooling cryogenic temperature condensation water regulating valve 19 reduces, to reduce the flow that low-temperature condensate flows through described empty prognosis gas cooler 3, eliminate or reduce the deviation of gas cooler inlet water temperature and described setting value; Vice versa.

In described air heat, warm condensate water control valve 7 controls its aperture according to the measured value of described air preheater inlet air temperature sensor 5;

When the air temperature value measured by described air preheater inlet air temperature sensor 5 is worth lower than air preheater entering air temperature setting value second, in described air heat, the aperture of warm condensate water control valve 7 increases, with warm condensate water in increasing flow through described sky pre-before the flow of air heater 4, eliminate or reduce the deviation that air preheater entering air temperature and described setting value second are worth; Vice versa.

Described air preheater entering air temperature setting value first value is more than or equal to air preheater entering air temperature setting value second and is worth.

Described flue gas cooling condensate water arm pressurization cycle pump 31 controls its running speed according to the measured value of described gas cooler outlet cooling-water temperature sensor 12 and described gas cooler exit gas temperature sensor 13 respectively or comprehensively.

When the water temperature value measured by described gas cooler outlet cooling-water temperature sensor 12 is lower than gas cooler outlet water temperature setting value, the rotating speed of described flue gas cooling condensate water arm pressurization cycle pump 31 reduces, to reduce the flow that condensate water flows through sky prognosis gas cooler 3, eliminate or reduce the deviation of gas cooler outlet water temperature and described setting value; Vice versa.

Or, when the cigarette temperature value measured by described gas cooler exit gas temperature sensor 13 is lower than gas cooler outlet cigarette temperature setting value, the rotating speed of described flue gas cooling condensate water arm pressurization cycle pump 31 reduces, to reduce the flow that condensate water flows through sky prognosis gas cooler 3, eliminate or reduce the deviation of gas cooler exit gas temperature and described setting value; Vice versa.

Or, the deviation of described gas cooler outlet water temperature and its setting value exports through gas cooler the controlled quentity controlled variable that the computing of water temperature control logic exports, the deviation exporting cigarette Wen Yuqi setting value with described gas cooler exports through gas cooler the controlled quentity controlled variable that fibre selection logical operation exports, and exports the controlled quentity controlled variable to described flue gas cooling condensate water arm pressurization cycle pump 31 rotating speed through weighting summation mode; When laying particular emphasis on the control of gas cooler outlet coolant-temperature gage, increase the weight that the computing of gas cooler outlet water temperature control logic exports controlled quentity controlled variable; When laying particular emphasis on the control of gas cooler exit gas temperature, increase the weight that the logical operation of gas cooler outlet fibre selection exports controlled quentity controlled variable;

The deviation that described low-temperature condensate loop branch pipe booster pump 26 running frequency is worth according to the measured value of air preheater inlet air temperature sensor 5 and air preheater entering air temperature setting value first controls; When the air temperature value measured by described air preheater inlet air temperature sensor 5 is worth lower than air preheater entering air temperature setting value first, the running frequency of described low-temperature condensate loop branch pipe booster pump 26 improves, to increase the flow that condensate water flows through described air heat condensate water arm 2, eliminate or reduce the deviation that air preheater entering air temperature and described air preheater entering air temperature setting value first are worth; Vice versa.

Described main condensate control valve 16 controls its aperture according to the measured value of described gas cooler outlet cooling-water temperature sensor 12 and described gas cooler exit gas temperature sensor 13 respectively or comprehensively.

When the water temperature value measured by described gas cooler outlet cooling-water temperature sensor 12 is lower than gas cooler outlet water temperature setting value, the aperture of described main condensate control valve 16 increases, to reduce the flow that condensate water flows through sky prognosis gas cooler 3, eliminate or reduce the deviation of gas cooler outlet water temperature and described setting value; Vice versa.

Or, when the cigarette temperature value measured by described gas cooler exit gas temperature sensor 13 is lower than gas cooler outlet cigarette temperature setting value, the aperture of described main condensate control valve 16 increases, to reduce the flow that condensate water flows through sky prognosis gas cooler 3, eliminate or reduce the deviation of gas cooler exit gas temperature and described setting value; Vice versa.

Or, the deviation of described gas cooler outlet water temperature and its setting value exports through gas cooler the controlled quentity controlled variable that the computing of water temperature control logic exports, the deviation exporting cigarette Wen Yuqi setting value with described gas cooler exports through gas cooler the controlled quentity controlled variable that fibre selection logical operation exports, and exports the aperture controlled quentity controlled variable to main condensate control valve 16 through weighting summation mode; When laying particular emphasis on the control of gas cooler outlet coolant-temperature gage, increase the weight that the computing of gas cooler outlet water temperature control logic exports controlled quentity controlled variable; When laying particular emphasis on the control of gas cooler exit gas temperature, increase the weight that the logical operation of gas cooler outlet fibre selection exports controlled quentity controlled variable;

Before described sky is pre-, Cryogenic air heat-setting water regulating valve 23 controls its aperture according to the measured value of described air heater outlet cooling-water temperature sensor 1.This system is used for preventing winter system water temperature from too lowly causing icing damage equipment.

Described cryogenic temperature condensation water recycle control valve 22 controls its aperture according to the measured value of described air preheater inlet air temperature sensor 5 or described air heater outlet cooling-water temperature sensor 1.This system be mainly used in air temperature increase requirement lower time, utilize the condensate water of more low temperature to add hot-air, take into account and control air preheater entering air temperature and air heater outlet water temperature, and reclaim steam turbine exhausted spare heat.

As the further improvement of technical scheme, described flue gas cooling condensate water arm 8 is provided with condensate water control valve, for providing hot water.

Present invention also offers a kind of method of backheat of low temperature of thermal power generation, residual heat integrative utilization, mainly comprise following cyclic process:

1) the most of condensate water in condensate water supervisor 20 flows through low-temperature level low-pressure heater 21, middle temperature level low-pressure heater 18, main condensate control valve 16 and high-temperature level low-pressure heater 17 successively;

Partial coagulation current in condensate water supervisor 20 through in enter air heat condensate water arm 2 after warm water main 14 more respectively and flue gas cools condensate water arm 8;

Partial coagulation current in condensate water supervisor 20 enter air heat condensate water arm 2, flue gas cooling condensate water arm 8 and air heat condensate water arm 2 flow through air heat condensate water control valve 6, flue gas cooling cryogenic temperature condensation water regulating valve 19 and empty pre-front these three control valves of Cryogenic air heat-setting water regulating valve 23 respectively after condensate water low temperature supplying supply mains 15 after more respectively.

2) low-temperature condensate that the pre-front air heater 4 of sky, the pre-front Cryogenic air heat-setting water regulating valve 23 of sky or cryogenic temperature condensation water recycle control valve 22 enter empty front Cryogenic air heater 4a is in advance flowed through, with the air flowed through in air duct 29, heat exchange in Cryogenic air heater 4a before sky is pre-; Described low-temperature condensate transfers heat to the air flowed through in air duct 29;

Flow through the low-temperature condensate in the air heat condensate water arm 2 of warm condensate water control valve 7 in air heat condensate water control valve 6 or air heat, with the air flowing through empty pre-front Cryogenic air heater 4a in air duct 29, heat exchange in air heater 4 before sky is pre-; Described low-temperature condensate transfers heat in air duct 29 air flowing through empty pre-front Cryogenic air heater 4a;

3) high-temperature flue gas in exhaust gases passes 30 flows through air preheater 11, with flow through in air duct 29 empty pre-before air heater 4 entered the air heat-exchange of air preheater 11 after heating;

Flue gas after the inherent air preheater 11 of exhaust gases passes 30 flows through sky prognosis gas cooler 3, transfer heat to flow through sky prognosis gas cooler 3 flue gas cooling condensate water arm 8 in condensate water; The condensate water absorbing fume afterheat gets back to the high temperature section of condensate water house steward 20 through flue gas cooling condensate water arm 8;

4) condensate water in the flue gas cooling condensate water arm 8 after empty prognosis gas cooler 3, flow through condensed water in high temperature recirculation pump and condensed water in high temperature recirculation control valve, the condensate water that before pre-respectively to sky, air heater 4 and empty prognosis gas cooler 3 provide temperature higher.

5) after the cooled all or part of condensate water flowed through in air heat condensate water arm 2 after empty front air heater 4 in advance and the pre-front Cryogenic air heater 4a of sky enters turbine low pressure cylinder steam drain after flowing through low-temperature condensate shower valve 28, hydraulic recovery mechanical device 37, leakage vacuum protection quick closing valve water-sealed valve 36 and atomizing sprayer again; Or, described cooled all or part of condensate water flows through the vapour survey that low-temperature condensate shower valve 28, hydraulic recovery mechanical device 37, leakage vacuum protection quick closing valve water-sealed valve 36 and atomizing sprayer enter low-temperature level low-pressure heater 21 or other steam heater, through condensate water and the steam heat exchange of atomizing spray, finally enter turbine condenser; The waste heat of part turbine discharge is absorbed by air cooled low-temperature condensate, finally transfer heat to the air entering boiler, or by air cooled low-temperature condensate, steam turbine low parameter rate of air sucked in required is increased, make the heat of extraction cycle be able to cascade utilization; Mixed condensate water enters condensate water supervisor 20 after turbine condenser and the boosting of steam turbine condensate pump, the partial coagulation water of condensate water supervisor 20 through different pipeline again enter described air heat condensate water arm 2 and described sky pre-before air heater 4 and sky pre-before Cryogenic air heater 4a, continuation heat transfer cycle;

Or, low-temperature circulating pipe control valve 33 and low-temperature circulating isolating valve 34 are closed, the cooled all or part of condensate water after empty pre-front air heater 4 and the pre-front Cryogenic air heater 4a of sky is flowed through successively through low-temperature condensate loop branch pipe steam heater 27 in air heat condensate water arm 2, low-temperature condensate loop branch pipe booster pump 26, low-temperature condensate loop branch pipe non-return valve 25, low-temperature condensate loop branch pipe valve 24 enters condensate water supervisor 20, its condensate water be responsible in 20 with condensate water mixes, mixed condensate water flows through more low-temperature level low-pressure heater 35 successively, low-temperature level low-pressure heater 21, described condensate water low temperature supplying supply mains 15, before described sky is pre-after Cryogenic air heat-setting water regulating valve 23, get back to the pre-front Cryogenic air heater 4a of described sky, form low temperature heat exchange cycle system,

Or, when low-temperature condensate loop branch pipe valve 24 and low-temperature circulating pipe control valve 33 are closed, the cooled all or part of condensate water flowed through in air heat condensate water arm 2 after empty pre-front air heater 4 and the pre-front Cryogenic air heater 4a of sky flows through low-temperature condensate loop branch pipe steam heater 27 successively, low-temperature condensate loop branch pipe booster pump 26, low-temperature condensate loop branch pipe non-return valve 25, low-temperature circulating isolating valve 34, cryogenic temperature condensation water recycle control valve 22 enters air heat condensate water arm 2 again, mix with the condensate water in air heat condensate water arm 2, all or part of condensate water in condensate water arm 2 is boosted through low-temperature condensate loop branch pipe booster pump 26 again, continue the backheat recirculation of more low temperature,

6) when low-temperature condensate loop branch pipe booster pump 26 is out of service, low-temperature condensate loop branch pipe non-return valve 25 is closed and check flowing, when low-temperature circulating isolating valve 34 cuts out, the partial coagulation water in condensate water supervisor 20 can enter air heat condensate water arm 2 through low-temperature circulating pipe control valve 33, cryogenic temperature condensation water recycle control valve 22 successively; Then after flowing through empty pre-front air heater 4 and the pre-front Cryogenic air heater 4a of sky successively, described condensate water supervisor 20 is got back to through low-temperature condensate loop branch pipe steam heater 27, low-temperature condensate loop branch pipe booster pump 26, low-temperature condensate loop branch pipe non-return valve 25, low-temperature condensate loop branch pipe valve 24, or get back to condensate water supervisor 20 through low-temperature condensate shower valve 28 and system equipment afterwards, carry out new circulation;

Or, when low-temperature condensate loop branch pipe booster pump 26 is out of service, low-temperature condensate loop branch pipe non-return valve 25 is closed and check flowing, described first low-temperature condensate loop branch pipe valve 33 cuts out, low-temperature condensate shower valve 28 is opened, described hand-operated valve 34 is opened, and the partial coagulation water in condensate water supervisor 20 can enter air heat condensate water arm 2 through low-temperature condensate loop branch pipe valve 24, low-temperature circulating isolating valve 34, cryogenic temperature condensation water recycle control valve 22 successively; Then after flowing through the pre-front air heater 4 of sky and the pre-front Cryogenic air heater 4a of sky successively, after low-temperature condensate shower valve 28, hydraulic recovery mechanical device 37, leakage vacuum protection quick closing valve water-sealed valve 36 and atomizing sprayer enter turbine low pressure cylinder steam drain; Or the vapour entering low-temperature level low-pressure heater 21 or other steam heater through low-temperature condensate shower valve 28, hydraulic recovery mechanical device 37, leakage vacuum protection quick closing valve water-sealed valve 36 and atomizing sprayer is surveyed; The condensate water of atomizing spray and steam heat exchange, absorb steam heat, and some vapor is condensed; Mixed condensate water enters condensate water supervisor 20 after the miscellaneous equipments such as system condenser and the boosting of steam turbine condensate pump, carries out new circulation;

7) condensate water after described empty prognosis gas cooler 3 in described flue gas cooling condensate water arm 8, through low temperature cigarette recirculation of cold water valve 38, the condensate water that before pre-respectively to described sky, air heater 4 and described empty prognosis gas cooler 3 provide temperature higher, the regulating power of raising system flue-gas temperature, air themperature and condensing water temperature and scope, adapt to unit starting and underrun operating mode.

The invention has the advantages that:

1, steam turbine backheat two kinds of extraction cycle of the boiler backheat of air preheat, feedwater heating and boiler exhaust gas UTILIZATION OF VESIDUAL HEAT IN, steam turbine exhaust steam waste heat utilization two kinds of UTILIZATION OF VESIDUAL HEAT IN combine by the present invention; The utilization of waste heat thermal source is utilized with air low-temperature receiver and combines; The two kinds of heat transfer cycle that the circulation of the high-temperature water of cooled flue gas and the water at low temperature that adds hot-air circulated combine; According to temperature height difference distribute respectively hot-fluid to, dynamically fully Optimum utilization thermal source and low-temperature receiver resource, makes waste heat in the thermodynamic cycle of generating, obtain best cascade utilization, promotes with can quality, reduces loss.

2, the invention solves the coupled problem of heated surface at the end of boiler security of operation and boiler efficiency, the wall temperature of the afterbody heat-transfer surface of conventional air preheater is added while reducing heat loss due to exhaust gas, under the prerequisite preventing the cold end corrosion of conventional air preheater and stifled ash, improve the benefit of flue gas heat recovery.

The present invention is multistage by air preheat being divided into, utilize the higher cigarette temperature of inter-stage to improve utilization rate of waste heat, utilize the higher wind-warm syndrome of inter-stage, avoid the serious stifled ash of conventional rotary type regenerative air preheater, improve air preheater heat exchange efficiency and service life, reduce flow resistance and purging, repair and maintenance cost etc.

3, the present invention is provided with the independent supply channel of different temperatures, is regulated the inflow temperature of each heat exchanger by contact pipeline and recirculating line water distribution, and water temperature and discharge regulate institute restricted less, and adjustable extent is larger; Adopt multi-stage heat exchanger to realize flue gas according to temperature grade and cool the cascade utilization process with the heat energy such as air stepped heating step by step; The present invention, by the setting of multiple water circulation system, also enhances independence and regulating power that wind, cigarette and high-temperature water and each parameter of water at low temperature regulate, has comparatively strong adaptability to unit starting and underrun operating mode;

When summer, air temperature increase requirement was lower, the present invention can utilize heat exchange area more than needed to adopt more low-temperature condensates to add hot-air, increases steam turbine low parameter and draws gas and the utilization rate of exhausted spare heat, improve system backheat and the UTILIZATION OF VESIDUAL HEAT IN thermal efficiency; The present invention can take into account and control air preheater entering air temperature and air heater outlet water temperature, can effectively prevent winter system water temperature from too lowly causing icing damage equipment;

4, namely the present invention makes the low parameters at different levels of Temperature Matching draw gas heat stepped heating wind by backheat water circulation, also the fume afterheat stepped heating wind at different levels of Temperature Matching can directly be utilized, the amount of drawing gas at different levels adjusts automatically with quantity of circulating water, and control simple and flexible, system flow drag losses is lower;

The present invention directly adds hot blast by utilizing high-temperature flue gas waste heat in part, improves empty pre-high temperature interstage temperature, thus improves gas cooler outlet water temperature, utilizes high temperature section fume afterheat to increase the benefit of heat recovery; The present invention can replace traditional steam air heater completely, the complication system removing traditional steam air heater and the high fault rate caused because of steam and water bursting.

5, invention enhances the low-temperature circulating system of independent operating, make full use of air low-temperature receiver more, can adopt the Harmon formula indirect air cooling mode of low-temperature condensate loop branch pipe steam heater as small condenser, or adopt the Hai Leshi indirect air cooling mode spraying low-temperature condensate to turbine discharge mouth, not only recoverable steam turbine exhausted spare heat, also improve steam turbine steam discharge vacuum and generating efficiency, had to the spike cooling effect of trace the summer high temperature period of Air-cooled Unit.Boiler fan makes the heat exchange of air heater sharp draft also contribute to strengthening stability and the wind resistance interference performance of Direct Air-cooled Unit turbine discharge vacuum in summer.

6, when the present invention adopts the Hai Leshi indirect air cooling mode to turbine discharge mouth spray low-temperature condensate, be that mechanical power is recycled by hydraulic recovery mechanical device by the partial pressure differential potential energy between the condensate water in air heat condensate water arm 2 and turbine discharge.

7, the present invention warm water main in condensate water has been arranged in parallel startup heater, to ensure device security when unit starting and underrun, avoids independently arranging startup heating pipe line, and reduces fluid resistance loss.

8, the present invention adopts intelligent control method, random groups load and variation of ambient temperature etc. can realize the operation of dynamic auto optimization system, and by monitoring amount of sulfur contenting in smoke or flue gas acid dew point in real time, the setting values such as auto modification gas cooler inlet water temperature, exhaust gas temperature, enhance unit to the adaptability using coal.

Accompanying drawing explanation

Fig. 1 is the structural representation of a kind of backheat of thermal power generation in the present invention, the system of residual heat integrative cascade utilization

1, air heater outlet cooling-water temperature sensor 2, air heat condensate water arm

3, empty prognosis gas cooler 4, empty pre-front air heater

High-temperature air heater before 4a, empty pre-front Cryogenic air heater 4b, sky are pre-

5, air preheater inlet air temperature sensor 6, air heat condensate water control valve

7, warm condensate water control valve 8, flue gas cooling condensate water arm in air heat

9, warm gas cooler in gas cooler inlet water temperature sensor 10, empty prognosis

10a, empty prognosis low-temperature flue gas cooler 10b, empty prognosis high-temperature flue gas cooler

11, air preheater 12, gas cooler outlet cooling-water temperature sensor

13, warm water main in gas cooler exit gas temperature sensor 14, condensate water

15, condensate water low temperature supplying supply mains 16, main condensate control valve

17, high-temperature level low-pressure heater 18, middle temperature level low-pressure heater

19, flue gas cooling cryogenic temperature condensation water regulating valve 20, condensate water supervisor

21, low-temperature level low-pressure heater 22, cryogenic temperature condensation water recycle control valve

23, empty pre-front Cryogenic air heat-setting water regulating valve 24, low-temperature condensate loop branch pipe valve

25, low-temperature condensate loop branch pipe non-return valve 26, low-temperature condensate loop branch pipe booster pump

27, warm condensate water loop branch pipe steam heater 28, low-temperature condensate shower valve

29, air duct 30, exhaust gases passes

31, flue gas cooling condensate water arm pressurization cycle pump 32, gas cooler condensate water manifold valve

33, low-temperature circulating pipe control valve 34, low-temperature circulating isolating valve

35, more low-temp low-pressure heater 36, leak vacuum protection quick closing valve water-sealed valve

37, hydraulic recovery mechanical device 38, low temperature cigarette recirculation of cold water valve

39, middle temperature cigarette recirculation of cold water valve 40, high temperature cigarette recirculation of cold water valve

41, heater 42, middle high temperature cigarette recirculation of cold water pump is started

43, high temperature cigarette recirculation of cold water booster pump

Detailed description of the invention

Now the invention will be further described by reference to the accompanying drawings.

As shown in Figure 1, the object of the invention is to, in order to solve, existing thermal power generator boiler smoke air backheating (air preheat) is not enough, boiler circuit backheat (feedwater heating) is not enough and residual heat from boiler fume and the low problem of steam turbine exhausted spare heat recovery utilization rate, the invention provides the system of a kind of backheat of thermal power generation, residual heat integrative cascade utilization.

Described air heat condensate water subsystem also comprises: empty pre-front Cryogenic air heater 4a and air heater outlet cooling-water temperature sensor 1;

Described air heat condensate water subsystem also comprises: low-temperature condensate loop branch pipe steam heater 27; Described low-temperature condensate loop branch pipe steam heater 27 is arranged on the described air heat condensate water arm 2 before described low-temperature condensate loop branch pipe booster pump 26.

This system also comprises more cryogenic temperature condensation water circulation system; Described more cryogenic temperature condensation water circulation system comprises: cryogenic temperature condensation water recycle arm and cryogenic temperature condensation water recycle control valve 22;

Described condensate water more low temperature supplying water system also comprises: low-temperature circulating pipe, low-temperature circulating pipe control valve 33, low-temperature circulating isolating valve 34 and more low-temp low-pressure heater 35;

Described empty prognosis gas cooler 3 is by empty prognosis high-temperature flue gas cooler 10b, and in empty prognosis, warm gas cooler 10 and empty prognosis low-temperature flue gas cooler 10a tri-part form; And three is connected on described flue gas cooling condensate water arm 8 along the condensate water flow direction successively;

After described low temperature cigarette recirculation of cold water valve 38 is opened, partial coagulation current air heater 4 before described sky is pre-in described flue gas cooling condensate water arm 8 in described empty prognosis low-temperature flue gas cooler 10a after heat absorption, directly utilizes part low-temperature flue gas waste heat air heater 4 before described sky is pre-to heat the air in described air duct 29;

Described condensate water supervisor 20 after described low-temperature condensate shower valve 28 flows to along condensate water and is provided with hydraulic recovery mechanical device 37 successively, leak vacuum protection quick closing valve water-sealed valve 36.

Described air duct 29 is provided with steam heater between described air preheater 11 and described air preheater inlet air temperature sensor 5, to come into operation when environment temperature is lower, guarantee that the air themperature entering described air preheater 11 reaches requirement, and make the exhaust gas temperature after described air preheater 11 reach requirement.

Described main condensate control valve 16 is provided with bypass valve in parallel with it, the metered flow sum of described main condensate control valve 16 and described bypass valve is more than or equal to the metered flow of described condensate water supervisor 20, and the metered flow of described bypass valve is less than the metered flow of described main condensate control valve 16; One of described main condensate control valve 16 and described bypass valve are in full-gear when normal operation, and another valve is in less flow restriction control state, to reduce total restriction loss of condensate water supervisor 20.

Described air duct 29 is provided with tunnel inlet air temperature sensor before Cryogenic air heater 4a before described sky is pre-, so that monitor the difference of its measured value and described air preheater inlet air temperature sensor 5 measured value, corresponding correction if desired adds the aperture of each condensate water control valve of hot-air.

Described flue gas cooling condensate water arm 8 on described condensate water supervisor 20 and described condensate water are responsible between the tie point of 20 and described main condensate control valve 16 and are provided with high-temperature level low-pressure heater 17, improve the benefit of waste heat recovery when condensate water is absorbed heat larger in described empty prognosis gas cooler 3.

In described condensate water, warm water main 14 is provided with the startup heater 41 of band bypass valve, in unit starting process, condensate water in described condensate water in warm water main 14 flows through described startup heater 41, heats condensate water in described condensate water in warm water main 14 by described startup heater 41 by external source; After unit starting, the bypass valve of described startup heater 41 is opened, and the condensate water in described condensate water in warm water main 14 flows through bypass valve and walks around described startup heater 41, to reduce SR;

Described flue gas cooling condensate water arm 8 is connected with outer supplying hot water pipeline after described gas cooler outlet cooling-water temperature sensor 12, and outer supplying hot water pipeline is provided with external heat water lines feed water valve, fume afterheat can be utilized externally to provide heat to make system.

Described air heat condensate water control valve 6 controls its aperture according to the measured value of described air preheater inlet air temperature sensor 5;

Described flue gas cooling condensate water arm 8 is provided with condensate water control valve, for providing hot water.

In other specific embodiments, consider the problem of cost, before described sky is pre-, high-temperature air heater 4b also can not install, and the other end of described condensed water in high temperature recirculation pipe is then connected directly between on the described flue gas cooling condensate water arm 8 before described flue gas cooling condensate water arm pressurization cycle pump 31.

It should be noted last that, above embodiment is only in order to illustrate technical scheme of the present invention and unrestricted.Although with reference to embodiment to invention has been detailed description, those of ordinary skill in the art is to be understood that, modify to technical scheme of the present invention or equivalent replacement, do not depart from the spirit and scope of technical solution of the present invention, it all should be encompassed in the middle of right of the present invention.

Claims

1. the backheat of a thermal power generation, the system of residual heat integrative cascade utilization, it is characterized in that, this system comprises: in air preheater subsystem, main condensate subsystem, condensate water, temperature is for water subsystem, condensate water low temperature supplying water subsystem, flue gas cooling condensate water subsystem and air heat condensate water subsystem; Described air preheater subsystem to connect in described flue gas cooling condensate water subsystem, described condensate water temperature respectively for water subsystem, described condensate water low temperature supplying water subsystem and described air heat condensate water subsystem, then gathers and be connected with described main condensate subsystem;

Described air preheater subsystem comprises air preheater (11), air duct (29), exhaust gases passes (30), empty pre-front air heater (4), air preheater inlet air temperature sensor (5);

Described air duct (29) is all connected with described air preheater (11) with described exhaust gases passes (30); Before described sky is pre-, air heater (4) is arranged on the front described air duct (29) of described air preheater (11) along air flow;

Described air preheater inlet air temperature sensor (5) is arranged on the pre-front described air duct (29) between air heater (4) and described air preheater (11) of described sky;

Described flue gas cooling condensate water subsystem comprises flue gas cooling condensate water arm (8), gas cooler condensate water manifold valve (32), flue gas cooling condensate water arm increases circulating pump (31), gas cooler inlet water temperature sensor (9), empty prognosis gas cooler (3), gas cooler exit gas temperature sensor (13) and gas cooler outlet cooling-water temperature sensor (12);

Described gas cooler condensate water manifold valve (32), described flue gas cooling condensate water arm increases circulating pump (31), described gas cooler inlet water temperature sensor (9), described empty prognosis gas cooler (3) and described gas cooler outlet cooling-water temperature sensor (12) flow to along condensate water and are successively set on described flue gas cooling condensate water arm (8);

Described gas cooler exit gas temperature sensor (13) is arranged on the described exhaust gases passes (30) after described empty prognosis gas cooler (3) along flue gas flow direction;

Described main condensate subsystem comprises condensate water supervisor (20), main condensate control valve (16), middle temperature level low-pressure heater (18) and low-temperature level low-pressure heater (21);

Described main condensate control valve (16), described middle temperature level low-pressure heater (18) and described low-temperature level low-pressure heater (21) flow to along condensate water and are successively set in described condensate water supervisor (20);

In described condensate water, temperature comprises warm water main (14) in condensate water for water subsystem;

Described condensate water low temperature supplying water subsystem comprises condensate water low temperature supplying supply mains (15), air heat condensate water control valve (6), flue gas cooling low-temperature condensate arm and flue gas cooling cryogenic temperature condensation water regulating valve (19);

Described air heat condensate water control valve (6) is arranged on described condensate water low temperature supplying supply mains (15); The air heat condensate water control valve (6) that one end of described flue gas cooling low-temperature condensate arm is connected to along the condensate water flow direction on condensate water low temperature supplying supply mains (15) is front; The other end of described flue gas cooling low-temperature condensate arm is connected on described flue gas cooling condensate water arm (8) between described flue gas cooling condensate water arm pressurization cycle pump (31) and described gas cooler condensate water manifold valve (32); Described flue gas cooling low-temperature condensate arm is provided with described flue gas cooling low-temperature condensate arm control valve (19);

Described air heat condensate water subsystem comprises air heat condensate water arm (2), warm condensate water control valve (7) in air heat, low-temperature condensate loop branch pipe booster pump (26), low-temperature condensate loop branch pipe non-return valve (25), low-temperature condensate loop branch pipe valve (24), cryogenic temperature condensation Water spray arm and low-temperature condensate shower valve (28);

Warm condensate water control valve (7) in described air heat, described low-temperature condensate loop branch pipe booster pump (26), described low-temperature condensate loop branch pipe non-return valve (25), described low-temperature condensate loop branch pipe valve (24) flows to according to condensate water and is successively set on described air heat condensate water arm (2);

Condensate water on described air heat condensate water arm (2) flows through warm condensate water control valve (7) in described air heat successively, air heater (4) before described sky is pre-, described low-temperature condensate loop branch pipe booster pump (26), described low-temperature condensate loop branch pipe non-return valve (25), described low-temperature condensate loop branch pipe valve (24);

One end of described cryogenic temperature condensation Water spray arm be connected to described sky pre-before on described air heat condensate water arm (2) between air heater (4) and described low-temperature condensate loop branch pipe booster pump (26), after its other end is connected to the turbine low pressure cylinder steam drain along vapor flow direction;

Described cryogenic temperature condensation Water spray arm flows to along condensate water and is provided with described low-temperature condensate shower valve (28) and atomizing sprayer successively;

One end of described flue gas cooling condensate water arm (8) is connected to and flows on described condensate water supervisor (20) after described main condensate control valve (16) along condensate water, and its other end is connected to the one end of warm water main (14) in described condensate water;

One end of described air heat condensate water arm (2) is connected to and flows on front described condensate water supervisor (20) of described low-temperature level low-pressure heater (21) along condensate water, and the other end is connected to the one end of warm water main (14) in described condensate water;

In described condensate water, two-way is divided in one end of warm water main (14), one end that one tunnel and described flue gas cool condensate water arm (8) is connected, another road is connected with one end of described air heat condensate water arm (2), and in described condensate water, the other end of warm water main (14) is connected on described condensate water supervisor (20) between described main condensate control valve (16) and described middle temperature level low-pressure heater (18);

One end of described condensate water low temperature supplying supply mains (15) is connected on the described air heat condensate water arm (2) in the pre-front air heater (4) of described sky and described air heat between warm condensate water control valve (7); The other end is connected on described condensate water supervisor (20) between described low-temperature level low-pressure heater (21) and described middle temperature level low-pressure heater (18).

2. the backheat of a kind of thermal power generation according to claim 1, the system of residual heat integrative cascade utilization, is characterized in that,

Described air heat condensate water subsystem also comprises: empty pre-front Cryogenic air heater (4a) and air heater outlet cooling-water temperature sensor (1);

Before described sky is pre-, Cryogenic air heater (4a) is arranged on the front described air duct (29) of the pre-front air heater (4) of described sky;

Described air heater outlet cooling-water temperature sensor (1) is arranged on the described air heat condensate water arm (2) after the pre-front Cryogenic air heater (4a) of described sky;

Described condensate water low temperature supplying water subsystem also comprises empty pre-front Cryogenic air heat-setting water arm and the pre-front Cryogenic air heat-setting water regulating valve (23) of sky;

Before described sky is pre-, to be connected to the air heat condensate water control valve (6) of condensate water low temperature supplying supply mains (15) front in one end of Cryogenic air heat-setting water arm, the other end be connected to described sky on air heat condensate water arm (2) pre-before between air heater (4) and the pre-front Cryogenic air heater (4a) of described sky;

Before described sky is pre-, Cryogenic air heat-setting water regulating valve (23) is arranged on the pre-front Cryogenic air heat-setting water arm of the front sky of described air heat condensate water control valve (6).

3. the backheat of a kind of thermal power generation according to claim 1, the system of residual heat integrative cascade utilization, is characterized in that, described air heat condensate water subsystem also comprises: low-temperature condensate loop branch pipe steam heater (27); Described low-temperature condensate loop branch pipe steam heater (27) is arranged on the front described air heat condensate water arm (2) of described low-temperature condensate loop branch pipe booster pump (26).

4. the backheat of a kind of thermal power generation according to claim 1-3, the system of residual heat integrative cascade utilization, it is characterized in that, the heating steam of described low-temperature condensate loop branch pipe steam heater (27) is that steam turbine last stage draws gas or turbine discharge;

This system also comprises more cryogenic temperature condensation water circulation system; Described more cryogenic temperature condensation water circulation system comprises: cryogenic temperature condensation water recycle arm and cryogenic temperature condensation water recycle control valve (22);

Described cryogenic temperature condensation water recycle arm one end is connected on the described air heat condensate water arm (2) between low-temperature condensate loop branch pipe valve (24) and low-temperature condensate loop branch pipe non-return valve (25), its other end be connected to described sky on described air heat condensate water arm (2) pre-before in air heater (4) and described air heat between warm condensate water control valve (7); Or, its other end be connected to described sky on described air heat condensate water arm (2) pre-before between Cryogenic air heater (4a) and the pre-front air heater (4) of described sky;

Described cryogenic temperature condensation water recycle arm is provided with cryogenic temperature condensation water recycle control valve (22).

5. the backheat of a kind of thermal power generation according to claim 1-4, the system of residual heat integrative cascade utilization, it is characterized in that, described condensate water more low temperature supplying water system also comprises: low-temperature circulating pipe, low-temperature circulating pipe control valve (33), low-temperature circulating isolating valve (34) and more low-temp low-pressure heater (35);

Described low-temperature circulating isolating valve (34) is arranged on the front cryogenic temperature condensation water recycle arm of described cryogenic temperature condensation water recycle control valve (22);

The described condensate water that described more low-temp low-pressure heater (35) is arranged between the tie point of described condensate water supervisor (20) and described air heat condensate water arm (2) and described low-temperature level low-pressure heater (21) is responsible on (20);

One end of described low-temperature circulating pipe is connected between described more low-temp low-pressure heater (35) in described condensate water supervisor (20) and described low-temperature level low-pressure heater (21); Its other end is connected between cryogenic temperature condensation water recycle control valve (22) on cryogenic temperature condensation water recycle arm and low-temperature circulating isolating valve (34);

Described low-temperature circulating pipe is provided with low-temperature circulating pipe control valve (33).

6. the backheat of a kind of thermal power generation according to claim 1, the system of residual heat integrative cascade utilization, it is characterized in that, described empty prognosis gas cooler (3) is by empty prognosis high-temperature flue gas cooler (10b), and in empty prognosis, warm gas cooler (10) and empty prognosis low-temperature flue gas cooler (10a) three part form; And three is connected on described flue gas cooling condensate water arm (8) along the condensate water flow direction successively;

Flue gas cooling condensate water arm (8) in described empty prognosis between warm gas cooler (10) and empty prognosis low-temperature flue gas cooler (10) is connected with low temperature cigarette recirculation of cold water pipe; The other end of described low temperature cigarette recirculation of cold water pipe be connected to warm condensate water control valve (7) and sky in the air heat on air heat condensate water arm (2) pre-before between air heater (4); Described low temperature cigarette recirculation of cold water pipe is provided with low temperature cigarette recirculation of cold water valve (38);

Flue gas cooling condensate water arm (8) in described empty prognosis between warm gas cooler (10) and empty prognosis high-temperature flue gas cooler (10b) is connected with middle temperature cigarette recirculation of cold water pipe; The other end of described middle temperature cigarette recirculation of cold water pipe is connected to low temperature cigarette recirculation of cold water valve (38) on described low temperature cigarette recirculation of cold water pipe and low temperature cigarette recirculation of cold water pipe and flue gas and cools between the tie point of condensate water arm (8); Described middle temperature cigarette recirculation of cold water pipe flows to along condensate water and is disposed with the pre-front high-temperature air heater (4b) of middle temperature cigarette recirculation of cold water valve (39), middle high temperature cigarette recirculation of cold water pump (42) and sky;

Described middle temperature cigarette recirculation of cold water pipe is connected with high temperature cigarette recirculation of cold water pipe between middle temperature cigarette recirculation of cold water valve (39) and middle high temperature cigarette recirculation of cold water pump (42); After the other end of described high temperature cigarette recirculation of cold water pipe is connected to gas cooler outlet cooling-water temperature sensor (12) on flue gas cooling condensate water arm (8); Described high temperature cigarette recirculation of cold water pipe flows to along condensate water and is disposed with high temperature cigarette recirculation of cold water booster pump (43) and high temperature cigarette recirculation of cold water valve (40);

Described air heat condensate water subsystem also comprises: empty pre-front high-temperature air heater (4b); Before described sky is pre-, high-temperature air heater (4b) is arranged on the described air duct (29) between described air preheater inlet air temperature sensor (5) and the pre-front air heater (4) of described sky.

7. the backheat of a kind of thermal power generation according to claim 6, the system of residual heat integrative cascade utilization, is characterized in that,

After described low temperature cigarette recirculation of cold water valve (38) is opened, partial coagulation current air heater (4) before described sky is pre-in described flue gas cooling condensate water arm (8) in described empty prognosis low-temperature flue gas cooler (10a) after heat absorption, directly utilizes part low-temperature flue gas waste heat air heater (4) before described sky is pre-to heat the air in described air duct (29);

Described low temperature cigarette recirculation of cold water valve (38) and described high temperature cigarette recirculation of cold water valve (40) are closed, after described middle temperature cigarette recirculation of cold water valve (39) is opened, the recirculation of warm condensate water in formation, make the partial coagulation current high-temperature air heater (4b) before described sky is pre-in described flue gas cooling condensate water arm (8) in described empty prognosis in warm gas cooler (10) after heat absorption, utilize warm fume afterheat high-temperature air heater (4b) before described sky is pre-in part to heat the air in described air duct (29);

Described low temperature cigarette recirculation of cold water valve (38) and described middle temperature cigarette recirculation of cold water valve (39) are closed, after described high temperature cigarette recirculation of cold water valve (40) is opened, form the recirculation of condensed water in high temperature, make the partial coagulation current high-temperature air heater (4b) before described sky is pre-in described flue gas cooling condensate water arm (8) in described empty prognosis high-temperature flue gas cooler (10b) after heat absorption, utilize the air of part high-temperature flue gas waste heat before sky is pre-in high-temperature air heater (4b) warmed up air passage (29).

8. the backheat of a kind of thermal power generation according to claim 1, the system of residual heat integrative cascade utilization; it is characterized in that, described condensate water supervisor (20) after described low-temperature condensate shower valve (28) flows to along condensate water and is provided with hydraulic recovery mechanical device (37) successively, leak vacuum protection quick closing valve water-sealed valve (36).

9. the backheat of a kind of thermal power generation according to claim 1, the system of residual heat integrative cascade utilization, it is characterized in that, described air heat condensate water control valve (6) controls its aperture according to the measured value of described air preheater inlet air temperature sensor (5);

When the air temperature value measured by described air preheater inlet air temperature sensor (5) is worth lower than described air preheater entering air temperature setting value first, the aperture of described air heat condensate water control valve (6) increases, with increase condensate water flow through described sky pre-before the flow of air heater (4), eliminate or reduce the deviation that air preheater entering air temperature and described setting value first are worth;

When the air temperature value measured by described air preheater inlet air temperature sensor (5) is worth higher than described air preheater entering air temperature setting value first, the aperture of described air heat condensate water control valve (6) reduces, with reduce condensate water flow through described sky pre-before the flow of air heater (4), eliminate or reduce the deviation that air preheater entering air temperature and described setting value first are worth;

Described flue gas cooling cryogenic temperature condensation water regulating valve (19) controls its aperture according to the measured value of described gas cooler inlet water temperature sensor (9);

When the inlet water temperature value measured by described gas cooler inlet water temperature sensor (9) is lower than gas cooler inlet water temperature setting value, the aperture of described flue gas cooling cryogenic temperature condensation water regulating valve (19) reduces, to reduce the flow that low-temperature condensate flows through described empty prognosis gas cooler (3), eliminate or reduce the deviation of gas cooler inlet water temperature and described setting value;

When the inlet water temperature value measured by described gas cooler inlet water temperature sensor (9) is higher than gas cooler inlet water temperature setting value, the aperture of described flue gas cooling cryogenic temperature condensation water regulating valve (19) increases, to increase the flow that low-temperature condensate flows through described empty prognosis gas cooler (3), eliminate or reduce the deviation of gas cooler inlet water temperature and described setting value;

In described air heat, warm condensate water control valve (7) controls its aperture according to the measured value of described air preheater inlet air temperature sensor (5);

When the air temperature value measured by described air preheater inlet air temperature sensor (5) is worth lower than air preheater entering air temperature setting value second, in described air heat, the aperture of warm condensate water control valve (7) increases, with warm condensate water in increasing flow through described sky pre-before the flow of air heater (4), eliminate or reduce the deviation that air preheater entering air temperature and described setting value second are worth;

When the air temperature value measured by described air preheater inlet air temperature sensor (5) is worth higher than air preheater entering air temperature setting value second, in described air heat, the aperture of warm condensate water control valve (7) reduces, with warm condensate water in reducing flow through described sky pre-before the flow of air heater (4), eliminate or reduce the deviation that air preheater entering air temperature and described setting value second are worth;

10. the backheat of a kind of thermal power generation according to claim 1, the system of residual heat integrative cascade utilization, it is characterized in that, flue gas cooling condensate water arm pressurization cycle pump (31) controls its running speed according to the measured value of described gas cooler outlet cooling-water temperature sensor (12) and described gas cooler exit gas temperature sensor (13) respectively or comprehensively;

When the water temperature value measured by described gas cooler outlet cooling-water temperature sensor (12) is lower than gas cooler outlet water temperature setting value, the rotating speed of described flue gas cooling condensate water arm pressurization cycle pump (31) reduces, to reduce the flow that condensate water flows through sky prognosis gas cooler (3), eliminate or reduce the deviation of gas cooler outlet water temperature and described setting value;

When the water temperature value measured by described gas cooler outlet cooling-water temperature sensor (12) is higher than gas cooler outlet water temperature setting value, the rotating speed of described flue gas cooling condensate water arm pressurization cycle pump (31) raises, to increase the flow that condensate water flows through sky prognosis gas cooler (3), eliminate or reduce the deviation of gas cooler outlet water temperature and described setting value;

Or, when the cigarette temperature value measured by described gas cooler exit gas temperature sensor (13) is lower than gas cooler outlet cigarette temperature setting value, the rotating speed of described flue gas cooling condensate water arm pressurization cycle pump (31) reduces, to reduce the flow that condensate water flows through sky prognosis gas cooler (3), eliminate or reduce the deviation of gas cooler exit gas temperature and described setting value;

When the cigarette temperature value measured by described gas cooler exit gas temperature sensor (13) is higher than gas cooler outlet cigarette temperature setting value, the rotating speed of described flue gas cooling condensate water arm pressurization cycle pump (31) raises, to increase the flow that condensate water flows through sky prognosis gas cooler (3), eliminate or reduce the deviation of gas cooler exit gas temperature and described setting value;

Or, the deviation of described gas cooler outlet water temperature and its setting value exports through gas cooler the controlled quentity controlled variable that the computing of water temperature control logic exports, the deviation exporting cigarette Wen Yuqi setting value with described gas cooler exports through gas cooler the controlled quentity controlled variable that fibre selection logical operation exports, and exports the controlled quentity controlled variable to described flue gas cooling condensate water arm pressurization cycle pump (31) rotating speed through weighting summation mode; When laying particular emphasis on the control of gas cooler outlet coolant-temperature gage, increase the weight that the computing of gas cooler outlet water temperature control logic exports controlled quentity controlled variable; When laying particular emphasis on the control of gas cooler exit gas temperature, increase the weight that the logical operation of gas cooler outlet fibre selection exports controlled quentity controlled variable.