CN102759094A - Thermal power plant smoke depth cooler heat return optimization on-line monitoring device and method - Google Patents

Abstract

The invention provides a thermal power plant smoke depth cooler heat return optimization on-line monitoring device and method. The device comprises a heat return optimization analyzing and computing server, a plant-level monitoring information system SIS (safety instrumented system) and a thermal generator set DCS (distributed control system), wherein the thermal generator set DCS comprises a smoke depth cooler thermodynamic system, a smoke system and a steam system; and the method comprises the following steps of: reading on-line monitoring data, judging whether the smoke discharge temperature is within a safe running range or not, computing the designed condensed water flow of the smoke depth cooler, adjusting the condensed water flow of the smoke depth cooler, computing the optimized condensed water flow of the smoke depth cooler, reading the on-line monitoring data of a steam system and a condensed water system in the power plant, computing the standard coal saving quantity after the smoke depth cooler runs, confirming the optimal distribution mode and running parameter of the smoke depth cooler, and adjusting a heat return system of the smoke depth cooler to be optimized on the line. According to the invention, the on-line monitoring and adjusting of a parameter-variable heat return optimization system can be realized.

Description

Coal steam-electric plant smoke deep cooler backheat is optimized on-Line Monitor Device and method

Technical field

The invention belongs to thermal power plant's UTILIZATION OF VESIDUAL HEAT IN technical field, be specifically related to coal steam-electric plant smoke deep cooler backheat and optimize on-Line Monitor Device and method.

Background technology

The exhaust gas temperature of thermal power plant is one of main performance index of boiler design, relates to the economy and the security of station boiler.Exhaust gas temperature generally about 120 ℃～140 ℃, uses the boiler of high-sulfur fuel, and exhaust gas temperature is about 140 ℃～150 ℃.But the exhaust gas temperature actual motion value of the many thermal power plants of China all is higher than about 20～50 ℃ of design load, and heat loss due to exhaust gas is big.Analysis shows, the operation exhaust gas temperature raises 10 ℃, and it is about 0.5%～0.7% that boiler efficiency reduces, and increases unit generation coal consumption 1.7～2.2g/kWh.

In order to adapt to the needs of energy-saving and emission-reduction, the flue gas deep cooler begins to be used widely.The flue gas deep cooler is that the flue gas waste heat recovery that is positioned at boiler back end ductwork utilizes system, the condensate of the flue gas heat heating therrmodynamic system of recovery.Extract condensate from low-pressure heater and carry out heat exchange, import higher level's low-pressure heater again behind the absorption heat as flue gas deep cooler working medium.Under the situation of the long period safe and highly efficient operation that does not influence existing therrmodynamic system, reduce exhaust gas temperature.The selection of flue gas deep cooler operational factor, mainly comprise import and export flue-gas temperature, import and export condensing water temperature, feedwater share, diversion return water heat regenerative system place selection.Because the flue gas deep cooler can be reduced to 90 ℃ with exhaust gas temperature, need control metallic walls surface temperature near acid dew point, avoid the flue gas deep cooler that serious cold end corrosion takes place, need this moment to select suitable water point, make inlet water temperature near optimum value.The connected mode of flue gas deep cooler in therrmodynamic system comprises with the low-pressure heater parallel connection and connects.Train can cause the resistance of the current that condense to increase, and required condensate pump head increases, and is not suitable for old power plant and transforms.So generally adopt parallel system, not only needn't change condensate pump, can also realize exhaust heat stepped utilization.When the flue gas deep cooler system of parallel system put into operation, along with the increase of feedwater share, exhaust gas temperature progressively reduced, and the outlet water temperature also progressively reduces, and the relative variation of full factory economy increases afterwards earlier and descends, and when it reaches maximum point, is best shunt volume.

China's coal changes various, and Various Seasonal there are differences electricity needs, and exhaust gas temperature can change.When the unit variable load operation, the bleeder steam parameter changes, and condensing capacity changes simultaneously.Arriving along with information age of fired power generating unit automation development; Power station computer monitoring system constantly perfect; Function is powerful day by day, but in existing thermal power plant heat regenerative system on-line monitoring and the fault diagnosis technology, does not comprise improved flue gas deep cooler therrmodynamic system regulation and control module.Therefore, when improved heat regenerative system parameter changed, prior art can not realize flue gas deep cooler backheat optimization on-line monitoring and regulation and control, influences full factory economy.

For this reason, be provided with and write backheat optimization analytical calculation software, operate in backheat and optimize on the analytical calculation server, the on-line monitoring that is applied to heat regenerative system optimization becomes problem demanding prompt solution.

Summary of the invention

For solving the problem that exists in the above-mentioned prior art, order of the present invention is to provide a kind of coal steam-electric plant smoke deep cooler backheat to optimize on-Line Monitor Device and method, realizes the on-line monitoring and the regulation and control of variable element backheat optimization system.

For achieving the above object, the technical scheme that the present invention adopted is:

A kind of coal steam-electric plant smoke deep cooler backheat is optimized on-Line Monitor Device; Comprise backheat optimization analytical calculation server 1, plant level supervisory information system SIS 2 and the thermoelectric generator group distributing control DCS of system 3, the said thermoelectric generator group distributing control DCS of system 3 comprises flue gas deep cooler therrmodynamic system 4, flue gas system 5 and vapour system 6.

A kind of coal steam-electric plant smoke deep cooler backheat is optimized the monitoring method of on-Line Monitor Device; Adopt C# language to write backheat and optimize analytical calculation software; Operate in backheat and optimize on the analytical calculation server 1, be applied to the on-line monitoring that heat regenerative system is optimized, its concrete steps are following:

The first step: read the on-line monitoring point data in flue gas deep cooler therrmodynamic system 4 and the flue gas system 5:

It is every at a distance from 1 minute to 5 minutes that backheat is optimized analytical calculation server 1, reads the flue gas mass flow data from the input gas temperature the flue gas deep cooler therrmodynamic system 4 of the thermoelectric generator group distributing control DCS of system 3 and pressure, exit gas temperature and pressure, incoming condensing water temperature and pressure, outlet condensing water temperature and pressure, flue gas deep cooler condensing water flow and flue gas system 5 from plant level supervisory information system SIS2;

Second step: judge that exhaust gas temperature is whether within the safe operation scope:

Backheat is optimized the flue gas deep cooler exit gas temperature data that analytical calculation server 1 reads according to the first step, judge if | monitor value-design load |＞10 ℃, then carried out for the 3rd step; If | monitor value-design load |≤10 ℃, then skipped for the 3rd step and the 4th step, directly carried out for the 5th step;

The 3rd step: the design condensing water flow that calculates the flue gas deep cooler:

Backheat is optimized structure and the size of analytical calculation server 1 to mounted flue gas deep cooler; Input gas temperature and pressure in the flue gas deep cooler therrmodynamic system 4 that reads according to the first step; The exit gas temperature of Reference Design and pressure; Calculate flue gas deep cooler design heat Q, computing formula is formula (1); According to the incoming condensing water temperature and pressure that the first step reads, outlet condensing water temperature and pressure, the design condensing water flow D of calculating flue gas deep cooler _d, computing formula is formula (2):

Q=q·(I′-I″)·3600，kJ/h (1)

$D_d=\frac{Q}{1000\·(i^{\′\′}-i^{\′})},\mathrm{kg}/h---\left(2\right)$

Q---flue gas mass flow, kg/s;

I '---flue gas deep cooler import flue gas enthalpy, kJ/kg;

I "-flue gas deep cooler outlet flue gas enthalpy, kJ/kg;

I "---flue gas deep cooler outlet condensate enthalpy, kJ/kg;

I'-flue gas deep cooler incoming condensing water enthalpy, kJ/kg;

The 4th step: the condensing water flow of adjustment flue gas deep cooler:

Optimize the rotating speed of analytical calculation server 1 online adjustment booster pump through backheat, change condensing water flow, when monitor value-design load＞10 ℃, increase condensing water flow, flue gas deep cooler heat is increased, thereby reach the purpose that exhaust gas temperature descends; When design load-monitor value＞10 ℃; Reduce condensing water flow; Flue gas deep cooler heat is reduced, thereby reach the purpose that exhaust gas temperature raises, monitor exit gas temperature and pressure in the flue gas deep cooler therrmodynamic system 4 in the first step simultaneously; Up to monitor value=design load, carried out for the 5th step;

The 5th step: the optimization condensing water flow that calculates the flue gas deep cooler:

Backheat is optimized structure and the size of analytical calculation server 1 to mounted flue gas deep cooler; According to input gas temperature and the pressure that the first step reads, exit gas temperature and pressure, flue gas volume flow; Calculate flue gas deep cooler heat Q, computing formula is formula (3); According to the incoming condensing water temperature and pressure that the first step reads, outlet condensing water temperature and pressure, the optimization condensing water flow D of calculating flue gas deep cooler _d, computing formula is formula (4);

$Q={\mathrm{\α}}_d[({\stackrel{\‾}{t}}_d-{\stackrel{\‾}{t}}_{m-1}){\mathrm{\η}}_m+\underset{r=x}{\overset{m-1}{\mathrm{\Σ}}}{\mathrm{\τ}}_r{\mathrm{\η}}_r],\mathrm{kJ}/\mathrm{kg}---\left(3\right)$

$D_d=\frac{1000\·q\·\mathrm{\ΔH}}{(\frac{3600}{({\mathrm{\η}}_b\·d)}+\mathrm{\ΔH})\·(29270\·{\mathrm{\η}}_b\·{\mathrm{\η}}_g)},g/\mathrm{kWh}---\left(4\right)$

In the formula:

The share of

-condensing water flow that the flue gas deep cooler bypasses, %;

---flue gas deep cooler outlet water temperature, ℃;

---m-1 heater outlet water temperature, ℃;

---m level heater vapour gas efficient, %;

η _r---r level heater vapour gas efficient, %;

τ _r---the enthalpy liter of 1kg water in heater r, kJ/kg;

η _b---boiler efficiency, %;

η _g---pipeline efficient, %;

The 6th step: the online measuring point data that reads power plant's vapour system and condensate system:

It is every at a distance from 1 minute to 5 minutes that backheat is optimized analytical calculation server 1, controls the DCS3 of system from thermoelectric generator group distributing and read import water enthalpy and hydrophobic enthalpy, condensing water flow, unit specific steam consumption and unit heat consumption rate from each low-pressure heater in the steam pressure of each extraction opening the vapour system 6 and enthalpy, main steam flow, initial steam enthalpy, condensing vapour enthalpy, reheated steam flow, the condensate system;

The 7th step: calculate flue gas deep cooler operation back standard coal saving amount:

Backheat is optimized analytical calculation server 1 to the different arrangements of flue gas deep cooler with low-pressure heater; Consider the cold end corrosion problem; Adopt equivalent enthalpy drop method, at line computation initial steam equivalent enthalpy drop Δ H and standard coal saving amount Δ b, computing formula is formula (5) and formula (6):

$\mathrm{\ΔH}={\mathrm{\α}}_d[({\stackrel{\‾}{t}}_d-{\stackrel{\‾}{t}}_{m-1}){\mathrm{\η}}_m+\underset{r=x}{\overset{m-1}{\mathrm{\Σ}}}{\mathrm{\τ}}_r{\mathrm{\η}}_r],\mathrm{kJ}/\mathrm{kg}---\left(5\right)$

$\mathrm{\Δb}=\frac{1000\·q\·\mathrm{\ΔH}}{(\frac{3600}{({\mathrm{\η}}_b\·d)}+\mathrm{\ΔH})\·(29270\·{\mathrm{\η}}_b\·{\mathrm{\η}}_g)},g/\mathrm{kWh}---\left(6\right)$

In the formula:

The share of

-condensing water flow that the flue gas deep cooler bypasses, %;

---flue gas deep cooler outlet water temperature, ℃;

---m-1 heater outlet water temperature, ℃;

---m level heater vapour gas efficient, %;

η _r---r level heater vapour gas efficient, %;

τ _r---the enthalpy liter of 1kg water in heater r, kJ/kg;

η _b---boiler efficiency, %;

η _g---pipeline efficient, %;

The 8th step: confirm concrete arrangement of optimized flue gas deep cooler and operational factor:

Backheat is optimized analytical calculation server 1 and is passed through economic analysis; Confirm that the device heat-economy improves at most relatively; It is the maximum arrangement of standard coal saving amount; Be the concrete arrangement of optimized flue gas deep cooler and low-pressure heater, best incoming condensing water temperature, outlet condensing water temperature and condensing water flow;

The 9th step: online adjustment flue gas deep cooler heat regenerative system is to optimization

According to the analysis result in the 8th step, backheat is optimized analytical calculation server 1 through adjustment intake and irrigating gate, as single intake list irrigating gate being switched to the single diversion of two water intakings, changes condensing water flow simultaneously, makes flue gas deep cooler heat regenerative system to optimization.

A kind of coal steam-electric plant smoke deep cooler of the present invention backheat is optimized the device and method of on-line monitoring, provides coal steam-electric plant smoke deep cooler backheat to optimize on-line monitoring device, realized that flue gas deep cooler backheat optimizes in line computation and regulation and control.The advantage that has is:

(1) when the cataclysm of power plant units load; Exhaust gas temperature rises sharply or rapid drawdown after making air preheater; Can in time monitor, and regulate the rotating speed control condensing capacity of circulating pump, the heat of regulation and control flue gas deep cooler; Guarantee that outlet cigarette temperature in the design load error range, ensures the safe and stable operation of tail flue gas treatment system deduster and desulfurizing tower.

(2) when thermal power plant's coal or load fluctuation; Exhaust gas temperature changes after causing air preheater; When therrmodynamic system is bled parameter and confluent variation; Through the economy computational analysis, the rotating speed that changes water intaking diversion position, adjusting pump changes the feedwater share, has reached the technique effect that ensures the long period safe and highly efficient operation of full factory economy and therrmodynamic system through on-line monitoring flue gas deep cooler backheat optimization system.

Description of drawings

Fig. 1 is the block diagram that coal steam-electric plant smoke deep cooler backheat of the present invention is optimized on-Line Monitor Device.

Fig. 2 is the flow chart that coal steam-electric plant smoke deep cooler backheat of the present invention is optimized the on-line monitoring method.

Fig. 3 is the computer software block diagram that computational analysis server of the present invention adopts.

The specific embodiment

Below in conjunction with the accompanying drawing and the specific embodiment the present invention is done further explain.

As shown in Figure 1; A kind of coal steam-electric plant smoke deep cooler of the present invention backheat is optimized on-Line Monitor Device; Comprise backheat optimization analytical calculation server 1, plant level supervisory information system SIS2 and the thermoelectric generator group distributing control DCS3 of system, the said thermoelectric generator group distributing control DCS3 of system comprises flue gas deep cooler therrmodynamic system 4, flue gas system 5 and vapour system 6.

Station boiler for certain model 300MW; Design flue gas deep cooler arrangement and operational factor are: parallelly connected with the 6# low-pressure heater; Irrigating gate is the outlet of 7# low-pressure heater; Return the mouth of a river and be 5# low-pressure heater inlet, 120 ℃ of outlet exhaust gas temperatures, exhaust gas temperature safe operation scope is 110 ℃ to 130 ℃.Backheat is optimized on-line monitoring and regulation and control, adopt device shown in Figure 1, flow chart shown in Figure 2 and computer software block diagram shown in Figure 3.

As shown in Figures 2 and 3; A kind of coal steam-electric plant smoke deep cooler of the present invention backheat is optimized the monitoring method of on-Line Monitor Device; Adopt C# language to write backheat and optimize analytical calculation software; Operate in backheat and optimize on the analytical calculation server 1, be applied to the on-line monitoring that heat regenerative system is optimized, its concrete steps are following:

The first step: read the on-line monitoring point data in flue gas deep cooler therrmodynamic system 4 and the flue gas system 5:

It is every at a distance from 2 minutes that backheat is optimized the analytical calculation server, reads the flue gas mass flow data from the input gas temperature the flue gas deep cooler therrmodynamic system 4 of the thermoelectric generator group distributing control DCS of system 3 and pressure, exit gas temperature and pressure, incoming condensing water temperature and pressure, outlet condensing water temperature and pressure, flue gas deep cooler condensing water flow and flue gas system 5 from plant level supervisory information system SIS 2;

Second step: judge that exhaust gas temperature is whether within the safe operation scope:

Backheat is optimized the flue gas deep cooler exit gas temperature data that analytical calculation server 1 reads according to the first step, if monitor value＞130 ℃ or＜110 ℃, then carried out for the 3rd step; If the 3rd step and the 4th step then skipped in 110 ℃≤monitor value≤130 ℃, directly carried out for the 5th step;

The 3rd step: the design condensing water flow that calculates the flue gas deep cooler:

Backheat is optimized structure and the size of analytical calculation server 1 to mounted flue gas deep cooler; Input gas temperature and pressure in the flue gas deep cooler therrmodynamic system 4 that reads according to the first step; The exit gas temperature of Reference Design and pressure; Calculate flue gas deep cooler design heat Q, computing formula is formula (1); According to the incoming condensing water temperature and pressure that the first step reads, outlet condensing water temperature and pressure, the design condensing water flow D of calculating flue gas deep cooler _d, computing formula is formula (2):

Q=q·(I′-I″)·3600，kJ/h (1)

$D_d=\frac{Q}{1000\·(i^{\′\′}-i^{\′})},\mathrm{kg}/h---\left(2\right)$

Q---flue gas mass flow, kg/s;

I '---flue gas deep cooler import flue gas enthalpy, kJ/kg;

I "-flue gas deep cooler outlet flue gas enthalpy, kJ/kg;

I "---flue gas deep cooler outlet condensate enthalpy, kJ/kg;

I'-flue gas deep cooler incoming condensing water enthalpy, kJ/kg;

The 4th step: the condensing water flow of adjustment flue gas deep cooler:

Optimize the rotating speed of analytical calculation server 1 online adjustment booster pump through backheat, change condensing water flow, when monitor value＞130 ℃, increase condensing water flow, flue gas deep cooler heat is increased, thereby reach the purpose that exhaust gas temperature descends; When monitor value＜110 ℃, reduce condensing water flow, flue gas deep cooler heat is reduced, thereby reach the purpose that exhaust gas temperature raises.Monitor exit gas temperature and pressure in the flue gas deep cooler therrmodynamic system 4 in the first step simultaneously, up to monitor value=120 ℃, carried out for the 5th step;

The 5th step: the optimization condensing water flow that calculates the flue gas deep cooler:

Backheat is optimized structure and the size of analytical calculation server 1 to mounted flue gas deep cooler; According to input gas temperature and the pressure that the first step reads, exit gas temperature and pressure, flue gas volume flow; Calculate flue gas deep cooler heat Q, computing formula is formula (3); According to the incoming condensing water temperature and pressure that the first step reads, outlet condensing water temperature and pressure, the optimization condensing water flow D of flue gas deep cooler _d, computing formula is cotype (4);

$Q={\mathrm{\α}}_d[({\stackrel{\‾}{t}}_d-{\stackrel{\‾}{t}}_{m-1}){\mathrm{\η}}_m+\underset{r=x}{\overset{m-1}{\mathrm{\Σ}}}{\mathrm{\τ}}_r{\mathrm{\η}}_r],\mathrm{kJ}/\mathrm{kg}---\left(3\right)$

$D_d=\frac{1000\·q\·\mathrm{\ΔH}}{(\frac{3600}{({\mathrm{\η}}_b\·d)}+\mathrm{\ΔH})\·(29270\·{\mathrm{\η}}_b\·{\mathrm{\η}}_g)},g/\mathrm{kWh}---\left(4\right)$

In the formula:

The share of

-condensing water flow that the flue gas deep cooler bypasses, %;

---flue gas deep cooler outlet water temperature, ℃;

---m-1 heater outlet water temperature, ℃;

---m level heater vapour gas efficient, %;

η _r---r level heater vapour gas efficient, %;

τ _r---the enthalpy liter of 1kg water in heater r, kJ/kg;

η _b---boiler efficiency, %;

η _g---pipeline efficient, %;

The 6th step: the online measuring point data that reads power plant's vapour system and condensate system:

It is every at a distance from 2 minutes that backheat is optimized analytical calculation server 1, controls the DCS of system 3 from thermoelectric generator group distributing and read import water enthalpy and hydrophobic enthalpy, condensing water flow, unit specific steam consumption and unit heat consumption rate from each low-pressure heater in the steam pressure of each extraction opening the vapour system 6 and enthalpy, main steam flow, initial steam enthalpy, condensing vapour enthalpy, reheated steam flow, the condensate system;

The 7th step: calculate flue gas deep cooler operation back standard coal saving amount:

Backheat is optimized analytical calculation server 1 to the different arrangements of flue gas deep cooler with low-pressure heater; Consider the cold end corrosion problem; Adopt equivalent enthalpy drop method, at line computation initial steam equivalent enthalpy drop Δ H and standard coal saving amount Δ b, computing formula is formula (5) and formula (6):

$\mathrm{\ΔH}={\mathrm{\α}}_d[({\stackrel{\‾}{t}}_d-{\stackrel{\‾}{t}}_{m-1}){\mathrm{\η}}_m+\underset{r=x}{\overset{m-1}{\mathrm{\Σ}}}{\mathrm{\τ}}_r{\mathrm{\η}}_r],\mathrm{kJ}/\mathrm{kg}---\left(5\right)$

$\mathrm{\Δb}=\frac{1000\·q\·\mathrm{\ΔH}}{(\frac{3600}{({\mathrm{\η}}_b\·d)}+\mathrm{\ΔH})\·(29270\·{\mathrm{\η}}_b\·{\mathrm{\η}}_g)},g/\mathrm{kWh}---\left(6\right)$

In the formula:

The share of

-condensing water flow that the flue gas deep cooler bypasses, %;

---flue gas deep cooler outlet water temperature, ℃;

---m-1 heater outlet water temperature, ℃;

---m level heater vapour gas efficient, %;

η _r---r level heater vapour gas efficient, %;

τ _r---the enthalpy liter of 1kg water in heater r, kJ/kg;

η _b---boiler efficiency, %;

η _g---pipeline efficient, %;

The 8th step: confirm concrete arrangement of optimized flue gas deep cooler and operational factor:

Backheat is optimized analytical calculation server 1 through economic analysis, confirms that the device heat-economy improves at most relatively, i.e. the arrangement that standard coal saving amount is maximum does; Parallelly connected with the 6# low-pressure heater; Irrigating gate is the 7# heater outlet, and returning the mouth of a river is the 5# calorifier inlets, 100 ℃ of best incoming condensing water temperature; 115 ℃ of outlet condensing water temperatures, standard coal saving amount 2.2g;

The 9th step: online adjustment flue gas deep cooler heat regenerative system is to optimization

According to the analysis result in the 8th step, it is the 7# heater outlet through the adjustment irrigating gate that backheat is optimized analytical calculation server 1, and returning the mouth of a river is the 5# calorifier inlets, changes condensing water flow simultaneously, makes flue gas deep cooler heat regenerative system to optimization.

Claims (2)

1. a coal steam-electric plant smoke deep cooler backheat is optimized on-Line Monitor Device; It is characterized in that: comprise backheat optimization analytical calculation server (1), plant level supervisory information system SIS (2) and the thermoelectric generator group distributing control DCS of system (3), the said thermoelectric generator group distributing control DCS of system (3) comprises flue gas deep cooler therrmodynamic system (4), flue gas system (5) and vapour system (6).

2. the coal steam-electric plant smoke deep cooler backheat of the said device employing of claim 1 is optimized the on-line monitoring method; It is characterized in that: adopt C# language to write backheat and optimize analytical calculation software; Operating in backheat optimizes on the analytical calculation server 1; Be applied to the on-line monitoring that heat regenerative system is optimized, its concrete steps are following:

The first step: read the on-line monitoring point data in flue gas deep cooler therrmodynamic system (4) and the flue gas system (5):

It is every at a distance from 1 minute to 5 minutes that backheat is optimized analytical calculation server (1), reads the flue gas mass flow data from the input gas temperature the flue gas deep cooler therrmodynamic system (4) of the thermoelectric generator group distributing control DCS of system (3) and pressure, exit gas temperature and pressure, incoming condensing water temperature and pressure, outlet condensing water temperature and pressure, flue gas deep cooler condensing water flow and flue gas system (5) from plant level supervisory information system SIS (2);

Second step: judge that exhaust gas temperature is whether within the safe operation scope:

Backheat is optimized the flue gas deep cooler exit gas temperature data that analytical calculation server (1) reads according to the first step, judge if | monitor value-design load |＞10 ℃, then carried out for the 3rd step; If | monitor value-design load |≤10 ℃, then skipped for the 3rd step and the 4th step, directly carried out for the 5th step;

The 3rd step: the design condensing water flow that calculates the flue gas deep cooler:

Backheat is optimized structure and the size of analytical calculation server (1) to mounted flue gas deep cooler; Input gas temperature and pressure in the flue gas deep cooler therrmodynamic system (4) that reads according to the first step; The flue gas mass flow; The exit gas temperature of Reference Design and pressure, at line computation flue gas deep cooler design heat Q, computing formula is a formula 1; According to the incoming condensing water temperature and pressure that the first step reads, outlet condensing water temperature and pressure are at the design condensing water flow D of line computation flue gas deep cooler _d, computing formula is a formula 2:

Q=q·(I′-I″)·3600，kJ/h (1)

$D_d=\frac{Q}{1000\·(i^{\′\′}-i^{\′})},\mathrm{kg}/h---\left(2\right)$

Q---flue gas mass flow, kg/s;

I '---flue gas deep cooler import flue gas enthalpy, kJ/kg;

I "-flue gas deep cooler outlet flue gas enthalpy, kJ/kg;

I "---flue gas deep cooler outlet condensate enthalpy, kJ/kg;

I'-flue gas deep cooler incoming condensing water enthalpy, kJ/kg;

The 4th step: the condensing water flow of adjustment flue gas deep cooler:

Optimize the rotating speed of the online adjustment booster pump of analytical calculation server (1) through backheat; Change condensing water flow, when monitor value-design load＞10 ℃, increase condensing water flow; Flue gas deep cooler heat is increased, thereby reach the purpose that exhaust gas temperature descends; When design load-monitor value＞10 ℃; Reduce condensing water flow; Flue gas deep cooler heat is reduced, thereby reach the purpose that exhaust gas temperature raises, monitor exit gas temperature and pressure in the flue gas deep cooler therrmodynamic system (4) in the first step simultaneously; Up to monitor value=design load, carried out for the 5th step;

The 5th step: the optimization condensing water flow that calculates the flue gas deep cooler:

Backheat is optimized structure and the size of analytical calculation server (1) to mounted flue gas deep cooler; According to input gas temperature and the pressure that the first step reads, exit gas temperature and pressure, flue gas mass flow; Calculate flue gas deep cooler heat, computing formula is formula (3); According to the incoming condensing water temperature and pressure that the first step reads, outlet condensing water temperature and pressure, the optimization condensing water flow D of calculating flue gas deep cooler _d, computing formula is formula (4);

$Q={\mathrm{\α}}_d[({\stackrel{\‾}{t}}_d-{\stackrel{\‾}{t}}_{m-1}){\mathrm{\η}}_m+\underset{r=x}{\overset{m-1}{\mathrm{\Σ}}}{\mathrm{\τ}}_r{\mathrm{\η}}_r],\mathrm{kJ}/\mathrm{kg}---\left(3\right)$

$D_d=\frac{1000\·q\·\mathrm{\ΔH}}{(\frac{3600}{({\mathrm{\η}}_b\·d)}+\mathrm{\ΔH})\·(29270\·{\mathrm{\η}}_b\·{\mathrm{\η}}_g)},g/\mathrm{kWh}---\left(4\right)$

In the formula:

The share of

-condensing water flow that the flue gas deep cooler bypasses, %;

---flue gas deep cooler outlet water temperature, ℃;

---m-1 heater outlet water temperature, ℃;

---m level heater vapour gas efficient, %;

η _r---r level heater vapour gas efficient, %;

τ _r---the enthalpy liter of 1kg water in heater r, kJ/kg;

η _b---boiler efficiency, %;

η _g---pipeline efficient, %;

The 6th step: the online measuring point data that reads power plant's vapour system and condensate system:

It is every at a distance from 1 minute to 5 minutes that backheat is optimized analytical calculation server (1), controls the DCS of system (3) from thermoelectric generator group distributing and read import water enthalpy and hydrophobic enthalpy, condensing water flow, unit specific steam consumption and unit heat consumption rate from each low-pressure heater in the steam pressure of each extraction opening the vapour system (6) and enthalpy, main steam flow, initial steam enthalpy, condensing vapour enthalpy, reheated steam flow, the condensate system;

The 7th step: calculate flue gas deep cooler operation back standard coal saving amount:

Backheat is optimized analytical calculation server (1) to the different arrangements of flue gas deep cooler with low-pressure heater; Consider the cold end corrosion problem; Adopt equivalent enthalpy drop method, at line computation initial steam equivalent enthalpy drop Δ H and standard coal saving amount Δ b, computing formula is formula (5) and formula (6):

$\mathrm{\ΔH}={\mathrm{\α}}_d[({\stackrel{\‾}{t}}_d-{\stackrel{\‾}{t}}_{m-1}){\mathrm{\η}}_m+\underset{r=x}{\overset{m-1}{\mathrm{\Σ}}}{\mathrm{\τ}}_r{\mathrm{\η}}_r],\mathrm{kJ}/\mathrm{kg}---\left(5\right)$

$\mathrm{\Δb}=\frac{1000\·q\·\mathrm{\ΔH}}{(\frac{3600}{({\mathrm{\η}}_b\·d)}+\mathrm{\ΔH})\·(29270\·{\mathrm{\η}}_b\·{\mathrm{\η}}_g)},g/\mathrm{kWh}---\left(6\right)$

In the formula:

The share of

-condensing water flow that the flue gas deep cooler bypasses, %;

---flue gas deep cooler outlet water temperature, ℃;

---m-1 heater outlet water temperature, ℃;

---m level heater vapour gas efficient, %;

η _r---r level heater vapour gas efficient, %;

τ _r---the enthalpy liter of 1kg water in heater r, kJ/kg;

η _b---boiler efficiency, %;

η _g---pipeline efficient, %;

The 8th step: confirm concrete arrangement of optimized flue gas deep cooler and operational factor:

Backheat is optimized analytical calculation server (1) and is passed through economic analysis; Confirm that the device heat-economy improves at most relatively; Be that the maximum arrangement of standard coal saving amount does; The concrete arrangement of optimized flue gas deep cooler and low-pressure heater, best incoming condensing water temperature, outlet condensing water temperature and condensing water flow;

The 9th step: online adjustment flue gas deep cooler heat regenerative system to optimization:

Analysis result according to the 8th step; Backheat is optimized analytical calculation server (1) through adjustment intake and irrigating gate; As single intake list irrigating gate being switched to the single diversion of two water intakings, change condensing capacity simultaneously, make flue gas deep cooler heat regenerative system to optimization.

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