CN107907005B - A kind of monitoring method of direct air cooled condenser fin heat-transfer surface clean conditions - Google Patents

Abstract

The invention discloses a method for monitoring the cleanness state of the fin heat exchange surface of a direct air-cooled condenser, which tests and calculates the ventilation volume of the heat exchange surface of the direct air-cooled condenser fin in two states, that is, the clean reference state and the normal state. Operating status; compare the ventilation volume calculated during normal operation with the ventilation volume data in the clean state of the air-cooled condenser. If the ventilation volume decreases by more than 10%, the fin heat exchange surface of the direct air-cooled condenser is seriously dirty. Cleaning is required. The formula provided by this method is used to calculate the ventilation volume of the fin heat exchange surface of the direct air-cooled condenser. The continuous monitoring of the ventilation volume can solve the monitoring problem of the fin cleaning status of the direct air-cooled condenser, and provide accurate information for the operation and maintenance of the power plant. Quantitative data; using the monitoring method of the clean state of the fin heat exchange surface of the direct air-cooled condenser, the abnormal state of the direct air-cooled condenser can be monitored in real time, which meets the needs of the economic analysis of the power plant.

Description

A method for monitoring the cleanliness of finned heat exchange surfaces of direct air-cooled condensers

technical field

The invention relates to a method for monitoring the clean state of the fin heat exchange surface of a direct air-cooled condenser.

Background technique

As the most important heat exchanger equipment of the direct air-cooling unit of the power plant, the direct air-cooling condenser undertakes the important function of dissipating the exhaust heat of the unit to the environment. With the development of power units with large capacity and high parameters, the performance of direct air-cooled condensers in power plants has an increasing impact on the economics of power plants. Taking the steam turbine of a 600MW direct air-cooled unit as an example, every increase in the pressure of the air-cooled condenser by 1 kPa will directly increase the coal consumption of the power plant for power generation by about 1g/kW·h. However, at present, there is no effective quantitative monitoring and evaluation of the parameters of the surface fouling state of the heat exchanger that affects the performance of the direct air-cooled condenser. Therefore, there is a big problem in the energy-saving evaluation of the air-cooled unit of the power plant.

Condenser cooling method: wet cooling method The wet cooling method is divided into two types: direct current cooling and cooling tower. Wet DC cooling generally absorbs a certain amount of water from natural water bodies such as rivers, rivers, lakes, and seas as cooling water. The cooling process centrifuge absorbs waste heat to raise the water temperature, and then discharges it into rivers, rivers, lakes, and seas. When the once-through cooling condition is not available, a cooling tower is required for cooling. The function of the cooling tower is to exchange heat between the cooling water carrying the waste heat and the air in the tower, so that the waste heat is transferred to the air and diffused into the atmosphere.

The dry cooling method is very difficult to replenish the water lost in the cooling process in water-scarce areas, and the air cooling method can solve this problem well. During the air cooling process, the heat exchange between air and water (or exhaust steam) is through the heat transfer on the surface of the radiator composed of metal tubes, and the heat of the water (or exhaust steam) in the tube is transferred to the air flowing outside the radiator. At present, there are three main types of air cooling systems used in power plants, namely direct air cooling systems, indirect air cooling systems with surface condensers (Harmon air cooling systems) and indirect air cooling systems with jet (mixed) condensers. system (Heller air cooling system). Direct air cooling is to use the air to directly condense the exhaust from the steam turbine, and the air and the exhaust are exchanged heat through the radiator. The Heller-type indirect air-cooling system is mainly formed by a spray condenser and an air-cooling tower equipped with a Fogo radiator. The high-purity neutral water in the system enters the condenser and directly mixes with the exhaust steam of the condenser and condenses the heated water. Most of the water is sent to the air-cooled radiator, and the cooling water after heat exchange is sent to the jet condenser for the next cycle. A small part of the neutral water is sent back to the water circulation system of the boiler and turbine after fine treatment. The Harmon type indirect air cooling system is also called the indirect air cooling system with surface condenser. In this system, the cooling water is separated from the boiler feed water, thus ensuring the quality of the boiler feed water. The Harmon air-cooling system consists of a surface condenser and an air-cooling tower, and the system is very similar to a conventional wet-cooling system. According to statistics, in the installed capacity of air cooling systems in the world, direct air cooling systems account for about 43%, surface condenser indirect air cooling systems account for about 24%, and mixed table condenser indirect air cooling systems account for about 33%.

Directly according to the working principle of the air-cooled system, the exhaust steam of the steam turbine is cooled by the air in the air-cooled condenser and condenses into water, and the heat exchange between the exhaust steam and the air is completed in the surface-type air-cooled condenser. In the process of direct air-cooled heat exchange, the cold air flowing outside the finned tube of the radiator is used to condense the saturated steam of the heat medium discharged from the steam turbine under vacuum in the condenser, and finally the condensed condensed water is treated back to the boiler.

The role of direct air-cooled condenser The development of direct air-cooled technology is mainly carried out around the tube bundle of direct air-cooled condenser. The air-cooled condenser is an important part of the cooling end of the air-cooled unit. Almost all the exhaust steam from the steam turbine will be condensed into condensed water in the condenser. The steam discharged from the steam turbine flows in the finned tube bundle of the condenser, and the air flows outside the finned tubes of the condenser to directly cool the steam. From the perspective of improving cooling efficiency, generally an electric fan unit is installed under the control system for forced ventilation or the tube bundle is built in a natural ventilation tower. In the existing operating units, the forced ventilation method is popular because of its good controllability and other advantages. application. Due to its outstanding features, direct air-cooled condensers have gradually been technically researched and gradually popularized and applied in various countries around the world. Compared with the direct air-cooled condenser system, the indirect air-cooled condenser system has more anchor chains, high cost, large maintenance, difficult operation and poor reliability, so it will only be the water-cooled condenser system and the direct air-cooled condenser system. A transition between air-cooled condenser systems, direct air-cooled condensers will be an important direction for the development of power plant cooling systems in the future.

Development and Present Situation of Direct Air-cooled Condenser The development and application of air-cooled condenser technology in power plants has a history of several decades. As early as 1939, Germany built an air-cooled generator set. In 1950, Professor Heller of Hungary first proposed the indirect air cooling technology of power plants. The development of power plant air cooling technology has gone through a development process from immature to mature. The finned tube radiator of the air cooling system is divided into three types according to the material: aluminum tube aluminum fin, steel tube aluminum fin and steel tube steel fin. According to the layout, there are currently four types of air cooling systems widely used: round aluminum tubes with aluminum fins, hot-dip galvanized oval steel tubes with rectangular fins, large-diameter hot-dip galvanized oval steel tubes with rectangular fins, and large-diameter flat tubes welded Snake-shaped aluminum fins. The development of direct air-cooling technology is mainly carried out around the pipe of direct air-cooled condensers. At present, the finned tubes used in air-cooled condensers are basically galvanized oval steel pipes with steel fins or round steel pipes with aluminum fins. piece. In the 1960s, in the early stage of the development of direct air-cooled condenser technology, due to the limitation of processing technology, the inner diameter of finned tubes was small, the length of single tube was short, and the number of tube bundles was large. Because the air (steam) flow of tube bundles composed of multiple rows will produce dead zones, the heat exchange area cannot be fully utilized, and the airflow resistance is large; the phenomenon of dead zones in the tube bundles is easy to appear and freeze during winter operation. Therefore, direct air cooling technology was basically used on generator sets with relatively small stand-alone capacity at that time. In the 1980s, the design and manufacturing technology of finned tubes has been greatly improved, and the diameter and length of the tubes have increased. Among them, the diameter of the base tube of the finned tubes has expanded to more than 50mm. Eliminated, a single row of pipes emerged. Single-row tubes have the advantages of sufficient heat exchange area, small flow resistance on the air side, not easy to freeze, easy to manufacture and low cost, which is conducive to promoting the development of air-cooled units in the direction of large units. With the continuous development of air-cooled condenser technology and its technical and economic advantages, it has laid a solid foundation for the application of direct air-cooling systems on large-capacity units. Air-cooling technology has been recognized and respected in more and more countries. use.

In normal operation, when the surface of the air-cooled condenser heat exchanger is deteriorating, the most direct impact is to reduce the fin gap on the heat exchange surface of the condenser, resulting in a decrease in the ventilation cross-section and a decrease in the cooling air volume of the fan, which ultimately directly affects Air-cooled condenser pressure. In actual operation, it is very difficult to calculate the surface fouling state parameters of the heat exchanger by directly calculating the surface heat transfer coefficient.

Therefore, there is an urgent need for a method for monitoring the cleanliness of the heat exchange surface of the direct air-cooled condenser fins to solve the current problems.

Contents of the invention

The purpose of the present invention is to provide a method for monitoring the cleanness of the heat exchange surface of the direct air-cooled condenser fins, which is used for monitoring the cleanliness of the heat exchange surface of the direct air-cooled condenser fins, and provides performance diagnosis and guidance for the cold end system of the steam turbine. Power plant operation provides important reference data.

In order to achieve the above object, the technical scheme that the present invention takes is as follows:

A method for monitoring the cleanliness of the finned heat exchange surface of a direct air-cooled condenser, comprising the following steps:

Step 1: Under the clean reference state of the direct air-cooled condenser, stop the direct air-cooled condenser fin cleaning system, and keep the operating frequency of the direct air-cooled condenser fan at the rated value of 50Hz, and measure and obtain the operating data of the clean reference state ;

Step 2: When the direct air-cooled condenser is in normal operation, shut down the direct air-cooled condenser fin cleaning system, and keep the operating frequency of the direct air-cooled condenser fan at the rated value of 50Hz, and measure and obtain the operating data in the normal operating state ;

Step 3, calculate the ventilation rate q 1 of the direct air-cooled condenser under the clean reference state according to the operation data measured in step ₁ ;

Step 4, calculate the ventilation rate q _t of the direct air-cooled condenser under normal operating conditions according to the operating data measured in step 2;

Step 5, compare the ventilation rate q ₁ of the direct air-cooled condenser in the clean reference state obtained in step 3 with the ventilation rate q ₂ of the direct air-cooled condenser in the normal operating state obtained in step 4, if the ventilation rate q ₂ in the normal operating state is lower than If the ventilation rate q ₁ is lower than a certain percentage in the cleaning reference state, the fin heat exchange surface of the direct air-cooled condenser is seriously dirty and needs to be cleaned.

Further, the operation data of the clean reference state obtained in the above step 1 includes: the ambient atmospheric pressure p ₁ in the clean reference state, the ambient temperature t ₁ at the inlet of the direct air-cooled condenser in the clean reference state, and the direct air-cooled condenser fan variable temperature in the clean reference state. Import power P ₁ .

Further, the operation data obtained in the above step 2 in the normal operation state includes: the ambient atmospheric pressure p ₂ in the normal operation state, the ambient temperature t ₂ at the inlet of the direct air-cooled condenser in the normal operation state, and the fan variable temperature of the direct air-cooled condenser in the normal operation state. Import power P ₂ .

Further, the calculation process of the ventilation volume q ₁ of the direct air-cooled condenser under the clean reference state in the above step 3 is: according to the ambient atmospheric pressure p ₁ under the clean reference state, the inlet ambient temperature t ₁ of the direct air-cooled condenser under the clean reference state and the clean The fan of the direct air-cooled condenser in the reference state changes the inlet power P ₁ , and the ventilation volume q ₁ of the direct air-cooled condenser in the clean reference state is calculated, and the calculation formula is as follows:

According to the air density properties, the following relationship exists:

From formula (2) and formula (3) can get:

In the formula, P is the inlet power of the air-cooled condenser fan, the unit is kW; ρ is the air density at the fan inlet, the unit is kg/m ³ ; p is the ambient atmospheric pressure, the unit is kPa; t is the direct air-cooled condenser Inlet ambient temperature, the unit is ℃; q is the direct ventilation volume of the air-cooled condenser, the unit is m ³ /h; the corner mark "g" is the guaranteed design state parameter of the air-cooled condenser; the corner mark "1" is the air-cooled condenser The parameters measured in the reference state of steam generator cleaning, n is a coefficient, take 0.33;

The parameters of the air-cooled condenser under the guaranteed design state, such as ambient atmospheric pressure p _g , condenser inlet ambient temperature t _g , and fan transformer inlet power P _g are all known quantities, which can be found from the technical parameter table provided by the manufacturer .

Further, the calculation process of the ventilation volume q _t of the direct air-cooled condenser in the normal operation state in the above step 2 is as follows: according to the ambient atmospheric pressure p ₂ in the normal operation state, the inlet ambient temperature t ₂ of the direct air-cooled condenser in the normal operation state and the normal In the operating state, the fan of the direct air-cooled condenser changes the inlet power P ₂ , and the ventilation volume q ₂ of the direct air-cooled condenser in the normal operating state is calculated. The calculation formula is as follows:

According to the air density properties, the following relationship exists:

From formula (6) and formula (7) can get:

In the formula, P is the air-cooled condenser fan variable inlet power, the unit is kW; ρ is the air density at the fan inlet, the unit is kg/m ³ ; p is the ambient atmospheric pressure, the unit is kPa; t is the direct air-cooled condenser inlet Ambient temperature, the unit is ℃; q is the ventilation volume of the direct air-cooled condenser, the unit is m ³ /h; the corner mark "g" is the guaranteed design state parameter of the air-cooled condenser; the corner mark "2" is the air-cooled condenser Parameters measured in normal operating state, n is the coefficient, take 0.33;

The parameters of the air-cooled condenser in the guaranteed design state, such as ambient atmospheric pressure pg, condenser inlet ambient temperature tg, and fan transformer inlet power Pg are all known quantities, which can be checked from the technical parameter table provided by the manufacturer.

Further, the operation data measurement of the direct air-cooled condenser cleaning reference state is selected during the overhaul of the direct air-cooled condenser unit, and after the fin heat exchange surface of the air-cooled condenser has been thoroughly washed with high-pressure water and mechanically cleaned conduct.

Further, the operation data measurement of the normal operation state of the direct air-cooled condenser is selected to be performed when the direct air-cooled condenser unit is operating normally and the operating load of the direct air-cooled condenser unit is stable.

Further, the percentage of the ventilation volume q2 in the normal operating state lower than the ventilation volume q1 in the clean reference state in the determination of the contamination of the condenser fin heat exchange surface is 10%.

Further, in the derivation of the characteristic formula of the fan power consumption and the ventilation volume of the direct air-cooled condenser, it is based on the assumption that the static pressure efficiency of the fan, the efficiency of the transmission device, the variable efficiency of the fan, and the efficiency of the fan inverter remain unchanged when the ventilation volume of the fan changes.

Compared with prior art, the beneficial effect that the present invention obtains is as follows:

The patent of the present invention adopts the method of indirect measurement and calculation, mainly by measuring atmospheric pressure, air-cooled condenser inlet ambient temperature, air-cooled condenser fan variable inlet power parameters, and using the formula provided by this method to calculate direct air-cooled condenser fins The ventilation volume of the heat exchange surface can solve the monitoring problem of the fin cleaning status of the direct air-cooled condenser through the continuous monitoring of the ventilation volume in normal operation, providing accurate quantitative data for the operation and maintenance of the power plant; the direct air-cooled condenser fin The method for monitoring the clean state of the sheet heat exchange surface can monitor the abnormal dirty state of the direct air-cooled condenser in real time, which meets the needs of the economic analysis of the power plant.

Detailed ways

The present invention will be further described in detail below.

A method for monitoring the cleanliness of the finned heat exchange surface of a direct air-cooled condenser, comprising the following steps:

Step 1: Under the clean reference state of the direct air-cooled condenser, stop the direct air-cooled condenser fin cleaning system, and keep the operating frequency of the direct air-cooled condenser fan at the rated value of 50Hz, and measure and obtain the operating data of the clean reference state , the data include: ambient atmospheric pressure p1 in the clean reference state, ambient temperature t1 at the inlet of the direct air-cooled condenser in the clean reference state, and fan variable inlet power P1 in the clean reference state;

Step 2: When the direct air-cooled condenser is in normal operation, shut down the direct air-cooled condenser fin cleaning system, and keep the operating frequency of the direct air-cooled condenser fan at the rated value of 50Hz, and measure and obtain the operating data in the normal operating state , the data include: ambient atmospheric pressure p2 in normal operating state, ambient temperature t2 at the inlet of direct air-cooled condenser in normal operating state, and fan variable inlet power P2 in normal operating state;

Step 2, calculate the ventilation rate q1 of the direct air-cooled condenser under the clean reference state according to the operating data measured in step 1;

According to the ambient atmospheric pressure p1 in the clean reference state, the ambient temperature t1 at the inlet of the direct air-cooled condenser in the clean reference state, and the fan variable inlet power P1 of the direct air-cooled condenser in the clean reference state, the ventilation volume of the direct air-cooled condenser in the clean reference state is calculated and obtained q1, the calculation formula is as follows:

According to the air density properties, the following relationship exists:

From formula (2) and formula (3) can get:

In the formula, P is the fan variable inlet power of the air-cooled condenser, the unit is kW; ρ is the air density at the fan inlet, the unit is kg/ ^m3 ; p is the ambient atmospheric pressure, the unit is kPa; t is the direct air-cooled condenser inlet Ambient temperature, the unit is ℃; q is the ventilation volume of the direct air-cooled condenser, the unit is m ³ /h; the corner mark "g" is the guaranteed design state parameter of the air-cooled condenser; the corner mark "1" is the air-cooled condenser The measured parameters in the clean reference state, n is the coefficient, take 0.33;

The parameters of the air-cooled condenser under the guaranteed design state, such as ambient atmospheric pressure p _g , condenser inlet ambient temperature t _g , and fan transformer inlet power P _g are all known quantities, which can be found from the technical parameter table provided by the manufacturer .

Step 4, calculate the ventilation rate q _t of the direct air-cooled condenser under normal operating conditions according to the operating data measured in step 2;

According to ambient atmospheric pressure p ₂ in normal operating state, ambient temperature t ₂ at the inlet of direct air-cooled condenser in normal operating state, and fan variable inlet power P ₂ in normal operating state, the direct air-cooled condenser in normal operating state is calculated and obtained The ventilation rate q ₂ is calculated as follows:

According to the air density properties, the following relationship exists:

From formula (6) and formula (7) can get:

In the formula, P is the air-cooled condenser fan variable inlet power, the unit is kW; ρ is the air density at the fan inlet, the unit is kg/m ³ ; p is the ambient atmospheric pressure, the unit is kPa; t is the direct air-cooled condenser inlet Ambient temperature, the unit is ℃; q is the ventilation volume of the direct air-cooled condenser, the unit is m ³ /h; the corner mark "g" is the guaranteed design state parameter of the air-cooled condenser; the corner mark "2" is the air-cooled condenser Parameters measured in normal operation state, n is the coefficient, take 0.33; the parameters of the air-cooled condenser in the guaranteed design state, such as ambient atmospheric pressure p _g , condenser inlet ambient temperature t _g , fan variable inlet power P _g It is a known quantity, which can be found from the technical parameter table provided by the manufacturer.

Step 5, compare the ventilation rate q ₁ of the direct air-cooled condenser in the clean reference state obtained in step 2 with the ventilation rate q ₂ of the direct air-cooled condenser in the normal operating state obtained in step 4, if the ventilation rate q ₂ in the normal operating state is lower than If the ventilation rate q ₁ is lower than a certain percentage in the cleaning reference state, the fin heat exchange surface of the direct air-cooled condenser is seriously dirty and needs to be cleaned.

The operation data measurement of the direct air-cooled condenser cleaning reference state is selected during the overhaul of the direct air-cooled condenser unit, and after the fin heat exchange surface of the air-cooled condenser has been thoroughly washed with high-pressure water and mechanically cleaned. The operation data measurement of the normal operation state of the direct air-cooled condenser is selected to be carried out when the direct air-cooled condenser unit is in normal operation and the direct air-cooled condenser unit has a stable operating load. The percentage of the ventilation volume _q2 in the normal operating state lower than the ventilation volume _q1 in the clean reference state in the determination of the contamination of the fin heat exchange surface of the condenser is 10%. In the derivation of the characteristic formula of the fan power consumption and the ventilation volume of the direct air-cooled condenser, it is based on the assumption that the static pressure efficiency of the fan, the transmission device efficiency, the variable efficiency of the fan, and the efficiency of the fan inverter remain unchanged when the ventilation volume of the fan changes.

The data collected by this test method is easy to measure, the judgment method is simple and easy to implement, and it can provide a reliable method for directly monitoring the performance status of the air-cooled condenser.

The patent of the present invention adopts the ventilation rate of the fin heat exchange surface of the direct air-cooled condenser as a judgment index for monitoring the clean state of the direct air-cooled condenser fin. The ventilation volume of the fin heat exchange surface of the direct air-cooled condenser calculated by this patent method has taken into account the change of the ventilation volume caused by the change of the operating environment of the direct air-cooled condenser. The principle of measurement and calculation of the patent of the present invention is as follows: in normal operation, when the surface of the air-cooled condenser heat exchanger is deteriorated, the most direct impact is to reduce the fin gap on the heat exchange surface of the condenser, resulting in a The reduction and the reduction of fan cooling air volume will eventually directly affect the pressure of the air-cooled condenser. In actual operation, it is very difficult to directly measure the relevant parameters of the air-cooled condenser and then calculate the parameters of the dirty state of the heat exchanger surface. Judgment index of condenser fin cleanliness. The change of ventilation volume is most directly reflected in the change of the total power consumption of the fan of the air-cooled condenser. Therefore, by measuring the variable inlet power of the fan of the air-cooled condenser and other environmental parameters, the heat exchange surface of the fin of the air-cooled condenser can be monitored. Changes in ventilation volume, and then monitor the cleanliness of the fin heat exchange surface of the air-cooled condenser.

The beneficial effect produced by adopting the above-mentioned technical scheme is: the patent of the present invention adopts the mode of indirect measurement and calculation, mainly by measuring atmospheric pressure, air-cooled condenser inlet ambient temperature, air-cooled condenser fan variable inlet power parameters, adopting this method The provided formula calculates the ventilation volume of the fin heat exchange surface of the direct air-cooled condenser, and the continuous monitoring of the ventilation volume in normal operation can solve the monitoring problem of the fin cleaning status of the direct air-cooled condenser, providing accurate information for the operation and maintenance of the power plant. Quantitative data; using the monitoring method of the clean state of the fin heat exchange surface of the direct air-cooled condenser, the abnormal state of the direct air-cooled condenser can be monitored in real time, which meets the needs of the economic analysis of the power plant.

The implementation manners described above are only preferred embodiments of the present invention, rather than an exhaustive list of feasible implementations of the present invention. For those skilled in the art, any obvious changes made to it without departing from the principle and spirit of the present invention should be considered to be included in the protection scope of the claims of the present invention.

Claims (7)

1. a kind of monitoring method of direct air cooled condenser fin heat-transfer surface clean conditions, it is characterised in that the following steps are included:

Step 1, in the case where direct air cooled condenser cleans normal condition, stoppage in transit direct air cooled condenser fin cleaning system, and make Direct air cooled condenser fan operation frequency is maintained at rated value 50Hz, and measurement obtains the operation data of cleaning normal condition；

Step 2, under direct air cooled condenser normal operating condition, stoppage in transit direct air cooled condenser fin cleaning system, and make Direct air cooled condenser fan operation frequency is maintained at rated value 50Hz, and measurement obtains the operation data of normal operating condition；

Step 3 measures the ventilation quantity that gained operation data calculates direct air cooled condenser under cleaning normal condition according to step 1 q₁；

Step 4 measures the ventilation quantity that gained operation data calculates direct air cooled condenser under normal operating condition according to step 2 q₂；

Step 5, the ventilation quantity q of direct air cooled condenser under cleaning normal condition obtained by comparison step three₁Just with step 4 gained The ventilation quantity q of direct air cooled condenser under normal operating status₂, if normal under operating status direct air cooled condenser ventilation quantity q₂ Lower than the ventilation quantity q of direct air cooled condenser under cleaning normal condition₁And relatively low exceed a certain percentage, then Direct Air-Cooled condensing Device fin heat-transfer surface is dirty more serious, is cleaned；

The ventilation quantity q of direct air cooled condenser under normal condition is cleaned in step 3₁Calculating process are as follows: according to cleaning normal condition Environment atmospheric pressure p₁, cleaning normal condition direct air cooled condenser import environment temperature t₁With cleaning normal condition Direct Air-Cooled Condenser blower becomes import power P₁, calculate the ventilation quantity q for obtaining direct air cooled condenser under cleaning normal condition₁, calculating formula is such as Under:

According to atmospheric density characteristic, there are following relationships:

It can be obtained by formula (2) and formula (3):

In formula, P is that direct air cooled condenser blower becomes import power, unit kW；ρ is fan inlet atmospheric density, and unit is kg/m³；P is environment atmospheric pressure, unit kPa；T is direct air cooled condenser import environment temperature, and unit is DEG C；Q is straight Meet the ventilation quantity of air cooling tubes condenser, unit m³/h；Footmark g is that direct air cooled condenser guarantees design point parameter；Footmark 1 is Direct air cooled condenser cleans the surveyed parameter of normal condition, and n is coefficient, takes 0.33；

The direct air cooled condenser guarantees design point parameter: environment atmospheric pressure p_g, direct air cooled condenser import environment temperature Spend t_g, direct air cooled condenser blower change import power P_gIt is known quantity, can be checked in by the technical data sheet that producer provides；

In step 4 under normal operating condition direct air cooled condenser ventilation quantity q₂Calculating process are as follows: according to normal operating condition Environment atmospheric pressure p₂, normal operating condition direct air cooled condenser import environment temperature t₂With normal operating condition Direct Air-Cooled Condenser blower becomes import power P₂, calculate the ventilation quantity q for obtaining direct air cooled condenser under normal operating condition₂, calculating formula is such as Under:

According to atmospheric density characteristic, there are following relationships:

It can be obtained by formula (6) and formula (7):

In formula, P is that direct air cooled condenser blower becomes import power, unit kW；ρ is fan inlet atmospheric density, and unit is kg/m³；P is environment atmospheric pressure, unit kPa；T is direct air cooled condenser import environment temperature, and unit is DEG C；Q is straight Meet the ventilation quantity of air cooling tubes condenser, unit m³/h；Footmark g is that direct air cooled condenser guarantees design point parameter；Footmark 2 is The surveyed parameter of direct air cooled condenser normal operating condition, n are coefficient, take 0.33；

The direct air cooled condenser guarantees design point parameter: environment atmospheric pressure p_g, direct air cooled condenser import environment temperature Spend t_g, direct air cooled condenser blower change import power P_gIt is known quantity, can be checked in by the technical data sheet that producer provides.

2. a kind of monitoring method of direct air cooled condenser fin heat-transfer surface clean conditions according to claim 1, special Sign is: the operation data that step 1 obtains the cleaning normal condition includes: cleaning normal condition environment atmospheric pressure p₁, it is clear Clean normal condition direct air cooled condenser import environment temperature t₁Become import with cleaning normal condition direct air cooled condenser blower Power P₁。

3. a kind of monitoring method of direct air cooled condenser fin heat-transfer surface clean conditions according to claim 1, special Sign is: the operation data that step 2 obtains the normal operating condition includes: normal operating condition environment atmospheric pressure p₂, just Normal operating status direct air cooled condenser import environment temperature t₂Become import with normal operating condition direct air cooled condenser blower Power P₂。

4. a kind of monitoring method of direct air cooled condenser fin heat-transfer surface clean conditions according to claim 1, special Sign is: the direct air cooled condenser cleaning normal condition operation data measurement selection is in direct air cooled condenser major overhaul When, and the fin heat-transfer surface of direct air cooled condenser carry out after thorough high pressure water flushing and mechanical chipping.

5. a kind of monitoring method of direct air cooled condenser fin heat-transfer surface clean conditions according to claim 1, special Sign is: the direct air cooled condenser normal operating condition operation data measurement selection is normal in direct air cooled condenser unit It is carried out when operation and stable direct air cooled condenser unit operating load.

6. a kind of monitoring method of direct air cooled condenser fin heat-transfer surface clean conditions according to claim 1, special Sign is: in the dirty judgement of condenser fin heat-transfer surface under normal operating condition direct air cooled condenser ventilation quantity q₂It is low In the ventilation quantity q for cleaning direct air cooled condenser under normal condition₁Percentage be 10%.

7. a kind of monitoring method of direct air cooled condenser fin heat-transfer surface clean conditions according to claim 1, special Sign is: direct air cooled condenser blower becomes import power and the ventilation quantity of direct air cooled condenser is passing through formula calculating process In, fan static efficiency, gear efficiency, blower become efficiency when based on the variation of blower ventilation amount, fan frequency converter efficiency is protected Hold constant hypothesis.