CN104729810A - Testing method of hot end air leakage rate of air pre-heater - Google Patents

Testing method of hot end air leakage rate of air pre-heater Download PDF

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CN104729810A
CN104729810A CN201510104591.1A CN201510104591A CN104729810A CN 104729810 A CN104729810 A CN 104729810A CN 201510104591 A CN201510104591 A CN 201510104591A CN 104729810 A CN104729810 A CN 104729810A
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air
air preheater
temperature
hot junction
flue gas
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CN104729810B (en
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杨兴森
崔福兴
郝卫东
胡志宏
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State Grid Corp of China SGCC
Electric Power Research Institute of State Grid Shandong Electric Power Co Ltd
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State Grid Corp of China SGCC
Electric Power Research Institute of State Grid Shandong Electric Power Co Ltd
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Abstract

The invention discloses a testing method of the hot end air leakage rate of an air pre-heater. The method includes the following steps that firstly the hot air temperature Ta,2, the cold air temperature Ta,1and the smoke temperature Tg,0 are obtained, wherein the hot air temperature refers to the temperature of the hot air flowing out of the air pre-heater, the cold air temperature refers to the temperature measured when the cold air enters the air pre-heater, and the smoke temperature refers to the temperature measured before the smoke enters the air pre-heater and is mixed with hot end leaked air; secondly, the smoke side efficiency eta of the air-pre-heater and the mass flow rate ratio km between the smoke and the air are obtained; thirdly, the hot end air leakage rate AL of the air pre-heater is obtained by taking parameter data obtained in the first step and the second step into a computational formula (1). The method can measure the mass ratio of hot end leaked air and the amount of the inlet smoke, namely the hot end air leakage rate, enables working situations of the air pre-heater to be analyzed and improved conveniently and is an important basis for improving the economy of a boiler system.

Description

The method of testing of air preheater hot junction air leak rate of air curtain
Technical field
The present invention relates to the method for testing of air preheater hot junction air leak rate of air curtain.
Background technology
Air preheater is the visual plant of large-sized boiler, and its performance has important impact to the thermal efficiency of steam generator system and the economy of steam generator system.Heavy duty boiler unit extensively adopts helicoid air preheater.Due to the difference of the reason of structure and flue gas, air pressure, understand some at the air of rotary regenerative air preheater air side flow and flow to fume side and discharge with flue gas, this part air is called as " leaking out ".Air leak rate of air curtain is leaked out and the mass ratio of flue gas, is the important performance indexes of air preheater.
To leak out the import and outlet that mainly result from air preheater, i.e. cold junction and hot junction.Leaking out of cold junction does not enter air preheater, is just mixed into the flue gas of outflow air preheater and discharges air preheater, not affecting the heat transfer process of air preheater inside.Leaking out of occurring in air preheater hot junction is mixed into and will enters the flue gas of air preheater, flows through air preheater and be discharged together with flue gas.The experienced temperature changing process that leaks out in hot junction be by air initial temperature when entering air preheater to discharge air preheater flue gas (with cold junction leak out mix before) temperature.Leaking out and cause the exhaust gas volumn of discharging air preheater to increase (containing leaking out of hot junction) in hot junction, increases thermal loss.Leaking out in hot junction has the impact of essence on the economy of air preheater performance and steam generator system, be analyze and improve air preheater working condition, improves the important evidence of steam generator system economy.In existing method of testing, can only measure and obtain air preheater and all leak out and the mass ratio of inlet flue gas, be leaked out in hot junction and lack the method for system with the surveying and calculating of the mass ratio (i.e. hot junction air leak rate of air curtain) of inlet flue gas amount always.The invention provides a kind of method of testing air preheater hot junction air leak rate of air curtain, can as the foundation evaluating air preheater working condition.
Patent 201110088424.4 provides a kind of method of testing air leak rate of air preheater, and the entirety of what it obtained is air preheater is leaked out situation, and namely cold junction and the hot junction summation of leaking out, cannot draw the situation leaked out in hot junction.Its method adopted depends on initial air leak rate of air curtain and exhaust gas temperature, does not relate to the situation leaked out in hot junction, cannot obtain the air leak rate of air curtain in hot junction.
Existing method cannot realize the test to measuring air preheater hot junction air leak rate of air curtain.
Summary of the invention
For solving the deficiency that prior art exists, the invention discloses the method for testing of air preheater hot junction air leak rate of air curtain, the present invention leaks out to hot junction and to measure with the mass ratio of inlet flue gas amount and hot junction air leak rate of air curtain, being convenient to analyze and improve air preheater working condition, is the important evidence improving steam generator system economy.
For achieving the above object, concrete scheme of the present invention is as follows:
The method of testing of air preheater hot junction air leak rate of air curtain, comprises the following steps:
Step one: measure the hot air temperature and hot blast temperature T that flow out air preheater a, 2, the temperature of cold air when entering air preheater and cold wind temperature T a, 1and before entering air preheater and the flue-gas temperature T do not leaked out when mixing with hot junction g, 0;
Step 2: the ratio k obtaining the fume side efficiency eta of air preheater, flue gas and the mass rate of air m;
Step 3: bring the hot junction air leak rate of air curtain A that computing formula (1) obtains air preheater into according to the supplemental characteristic that step one and step 2 obtain l:
A L = [ 1 - k m η ] T a , 1 + k m η T g , 0 - T a , 2 k m ( 1 - η ) ( T a , 2 - T a , 1 ) - - - ( 1 )
In formula, η is the fume side efficiency of air preheater; T a, 2for flowing out hot air temperature and the hot blast temperature of air preheater; T a, 1for temperature when cold air enters air preheater and cold wind temperature; T g, 0for before entering air preheater and the flue-gas temperature of not leaking out when mixing with hot junction, the flue-gas temperature of namely higher level's heating surface outlet; k mfor flue gas and the ratio of the mass rate of air.
Under many circumstances, air and flue gas specific heat are more or less the same, and can ignore.Specific heat is multiplied by the total amount of heat that quality and the temperature difference obtain heat interchange, and air is different with the mass rate of flue gas, and the total amount of heat exchanged is also different, so be necessary the difference considering mass rate.
The computing formula of the hot junction air leak rate of air curtain of described air preheater leaks out according to the thermal equilibrium relational expression of air preheater, the fume side effectiveness formula of air preheater and the hot junction that describes air preheater to mix the formula reducing this process of heat medium temperature entering air preheater entrance with the flue gas entering air preheater and combine to solve and obtain.
Leak out and mix with the flue gas entering air preheater the heat medium temperature reducing and enter air preheater entrance in the hot junction of described air preheater, this process prescription is:
c aT a,2A Lm g+c gT g,0m g＝c gT g,1m g+A Lm gc aT g,1(2)
In formula, c a, c gbe respectively the quality specific heat of air and flue gas; m gfor entering air preheater and not comprising the mass rate of the flue gas leaked out in hot junction; T g1for leaking out the temperature after mixing in flue gas and hot junction, ignoring the difference of the quality specific heat of air and flue gas, obtaining:
T a,2A L+T g,0＝T g,1+A LT g,1(3)
Obtained by (3) formula
T g , 1 = T a , 2 A L + T g , 0 1 + A L = T g , 0 - A L 1 + A L ( T g , 0 - T a , 2 ) - - - ( 4 ) .
According to the fume side efficiency of air preheater, draw
T g , 1 - T g , 2 T g , 1 - T a , 1 = η - - - ( 5 )
In formula, T g1for leaking out the temperature after mixing in flue gas and hot junction, T g, 2for flowing out the flue gas (comprising hot junction leaked-in air) of air preheater and the temperature of not leaking out when mixing with cold junction.
By the thermal equilibrium relation of air preheater, obtain
m a(T a,2-T a,1)+A Lm g(T g,2-T a,1)＝m g(T g,0-T g,2) (6)
In formula, m afor flowing out the mass rate of the air of air preheater, m gfor entering air preheater and not comprising the mass rate of the flue gas leaked out in hot junction, T g, 2for the temperature that the flue gas (comprising hot junction leaked-in air) flowing out air preheater does not leak out when mixing with cold junction, (6) formula have ignored the difference of the quality specific heat of air and flue gas, in flue gas, vapour content is not high, the quality specific heat of flue gas and air is very close.
Beneficial effect of the present invention:
The present invention leaks out to hot junction and to measure with the mass ratio of inlet flue gas amount and hot junction air leak rate of air curtain, and being convenient to analyze and improve air preheater working condition, is the significant data foundation improving steam generator system economy.Reduce the important content that air leak rate of air curtain is air preheater repair and maintenance and technological transformation, and could shoot the arrow at the target in the source that the Air Leakage administering air preheater must first clearly leak out, the size of hot junction air leak rate of air curtain judges to leak out the foundation of situation in hot junction, is also that hot end seal is the need of maintenance and reconstruction and the basis for estimation safeguarding correctional effect.The hot junction of air preheater leak out leak out from cold junction different on the impact of boiler thermal output, determine the numerical value of hot junction air leak rate of air curtain to analysis improve boiler economics have great importance.
Embodiment:
The method of testing actual application leaked out in air preheater hot junction of the present invention:
1. maintain boiler in rated load stable operation, keep air capacity and fuel quantity stable;
2. record cold wind temperature, hot blast temperature and air preheater entrance flue gas temperature;
3. the ratio of the fume side efficiency that obtains air preheater and flue gas and the mass rate of air of being tabled look-up by the performance calculation book of boiler and air preheater;
4. calculate hot junction air leak rate of air curtain according to (1) formula.
Application example:
The air preheater that certain boiler adopts, its fume side efficiency is 0.7, the ratio of the air preheater inlet flue gas flow under declared working condition and air preheater outlet air flow is 1.15, then calculate the air leak rate of air curtain in hot junction according to (1) formula and cold wind temperature, hot blast temperature and air preheater entrance flue gas temperature as follows:
Principle of the present invention is as follows:
Leak out and mix with the flue gas entering air preheater the heat medium temperature reducing and enter air preheater entrance in the hot junction of air preheater, this process can be described as:
c aT a,2A Lm g+c gT g,0m g＝c gT g,1m g+A Lm gc aT g,1(2)
In formula, c a, c gbe respectively the quality specific heat of air and flue gas; m gfor entering the mass rate (not comprising hot junction to leak out) of the flue gas of air preheater; T g1for leaking out the temperature after mixing in flue gas and hot junction.Ignore the difference of specific heat, obtain
T a,2A L+T g,0＝T g,1+A LT g,1(3)
Obtained by (3) formula
T g , 1 = T a , 2 A L + T g , 0 1 + A L = T g , 0 - A L 1 + A L ( T g , 0 - T a , 2 ) - - - ( 4 )
According to the fume side efficiency of air preheater, draw
T g , 1 - T g , 2 T g , 1 - T a , 1 = η - - - ( 5 )
In formula, η is the fume side efficiency of air preheater, %; T g, 2for flowing out flue gas (the comprising hot junction leaked-in air) temperature (do not leak out with cold junction and mix) of air preheater, DEG C; T a, 1for the temperature (cold wind temperature) when cold air enters air preheater.
By the thermal equilibrium relation of air preheater, obtain
m a(T a,2-T a,1)+A Lm g(T g,2-T a,1)＝m g(T g,0-T g,2) (6)
In formula, m afor flowing out the mass rate of the air of air preheater.
(6) formula have ignored the difference of flue gas and air specific heat equally, and in flue gas, vapour content is not high, the quality specific heat of flue gas and air is very close.
By (4), (5), (6) formula simultaneous, hot junction air leak rate of air curtain can be solved, see (1) formula.
A L = [ 1 - k m η ] T a , 1 + k m η T g , 0 - T a , 2 k m ( 1 - η ) ( T a , 2 - T a , 1 ) - - - ( 1 )
Test to hot junction air leak rate of air curtain and calculating can be completed according to (1) formula.
Although above-mentioned, the specific embodiment of the present invention is described; but not limiting the scope of the invention; one of ordinary skill in the art should be understood that; on the basis of technical scheme of the present invention, those skilled in the art do not need to pay various amendment or distortion that creative work can make still within protection scope of the present invention.

Claims (5)

1. the method for testing of air preheater hot junction air leak rate of air curtain, is characterized in that, comprises the following steps:
Step one: measure the hot air temperature and hot blast temperature T that flow out air preheater a, 2, the temperature of cold air when entering air preheater and cold wind temperature T a, 1and before entering air preheater and the flue-gas temperature T do not leaked out when mixing with hot junction g, 0;
Step 2: the ratio k obtaining the fume side efficiency eta of air preheater, flue gas and the mass rate of air m;
Step 3: bring the hot junction air leak rate of air curtain A that computing formula (1) obtains air preheater into according to the supplemental characteristic that step one and step 2 obtain l:
A L = [ 1 - k m η ] T a , 1 + k m η T g , 0 - T a , 2 k m ( 1 - η ) ( T a , 2 - T a , 1 ) - - - ( 1 )
In formula, η is the fume side efficiency of air preheater; T a, 2for flowing out hot air temperature and the hot blast temperature of air preheater; T a, 1for temperature when cold air enters air preheater and cold wind temperature; T g, 0for before entering air preheater and the flue-gas temperature of not leaking out when mixing with hot junction, the flue-gas temperature of namely higher level's heating surface outlet; k mfor flue gas and the ratio of the mass rate of air.
2. the method for testing of air preheater hot junction as claimed in claim 1 air leak rate of air curtain, it is characterized in that, the computing formula of the hot junction air leak rate of air curtain of described air preheater leaks out according to the thermal equilibrium relational expression of air preheater, the fume side effectiveness formula of air preheater and the hot junction that describes air preheater to mix the formula reducing this process of heat medium temperature entering air preheater entrance with the flue gas entering air preheater and combine to solve and obtain.
3. the method for testing of air preheater hot junction as claimed in claim 2 air leak rate of air curtain, it is characterized in that, leak out and mix with the flue gas entering air preheater the heat medium temperature reducing and enter air preheater entrance in the hot junction of described air preheater, this process prescription is:
c aT a,2A Lm g+c gT g,0m g＝c gT g,1m g+A Lm gc aT g,1(2)
In formula, c a, c gbe respectively the quality specific heat of air and flue gas; m gfor entering air preheater and not comprising the mass rate of the flue gas leaked out in hot junction; T g1for leaking out the temperature after mixing in flue gas and hot junction, ignoring the difference of the quality specific heat of air and flue gas, obtaining:
T a,2A L+T g,0＝T g,1+A LT g,1(3)
Obtained by (3) formula
T g , 1 = T a , 2 A L + T g , 0 1 + A L = T g , 0 - A L 1 + A L ( T g , 0 - T a , 2 ) - - - ( 4 ) .
4. the method for testing of air preheater hot junction as claimed in claim 2 air leak rate of air curtain, is characterized in that, according to the fume side efficiency of air preheater, draw
T g , 1 - T g , 2 T g , 1 - T a , 1 = η - - - ( 5 )
In formula, T g1for leaking out the temperature after mixing in flue gas and hot junction, T g, 2comprise hot junction leaked-in air not leak out with cold junction the flue-gas temperature mixed for flowing out air preheater.
5. the method for testing of air preheater hot junction as claimed in claim 2 air leak rate of air curtain, is characterized in that, by the thermal equilibrium relation of air preheater, obtain
m a(T a,2-T a,1)+A Lm g(T g,2-T a,1)＝m g(T g,0-T g,2) (6)
In formula, m afor flowing out the mass rate of the air of air preheater, m gfor entering air preheater and not comprising the mass rate of the flue gas leaked out in hot junction, T g, 2for flow out air preheater comprise hot junction leaked-in air and the flue-gas temperature of not leaking out when mixing with cold junction, ignore the difference of the quality specific heat of air and flue gas.
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110285931A (en) * 2019-07-08 2019-09-27 广州珠江电力有限公司 A kind of detection method of heat-engine plant desulfurizer flue gas heat-exchange unit air leak rate of air curtain
CN114397069A (en) * 2022-01-05 2022-04-26 华北电力科学研究院有限责任公司 Method and device for determining air leakage rate of air preheater with two bins

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040128111A1 (en) * 1998-03-24 2004-07-01 Lang Fred D. Method for detecting heat exchanger tube failures and their location when using input/loss performance monitoring of a recovery boiler
CN102213708A (en) * 2011-04-09 2011-10-12 山东电力研究院 Method for testing air leak rate of air preheater
CN103105269A (en) * 2011-11-09 2013-05-15 华北电力科学研究院有限责任公司 Measuring method of air leakage rate of primary air of air pre-heater
CN103323273A (en) * 2013-05-24 2013-09-25 国家电网公司 Method for detecting performance of power station boiler air pre-heater

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040128111A1 (en) * 1998-03-24 2004-07-01 Lang Fred D. Method for detecting heat exchanger tube failures and their location when using input/loss performance monitoring of a recovery boiler
CN102213708A (en) * 2011-04-09 2011-10-12 山东电力研究院 Method for testing air leak rate of air preheater
CN103105269A (en) * 2011-11-09 2013-05-15 华北电力科学研究院有限责任公司 Measuring method of air leakage rate of primary air of air pre-heater
CN103323273A (en) * 2013-05-24 2013-09-25 国家电网公司 Method for detecting performance of power station boiler air pre-heater

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110285931A (en) * 2019-07-08 2019-09-27 广州珠江电力有限公司 A kind of detection method of heat-engine plant desulfurizer flue gas heat-exchange unit air leak rate of air curtain
CN114397069A (en) * 2022-01-05 2022-04-26 华北电力科学研究院有限责任公司 Method and device for determining air leakage rate of air preheater with two bins
CN114397069B (en) * 2022-01-05 2024-02-02 华北电力科学研究院有限责任公司 Method and device for determining air leakage rate of air preheater with two bins

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