For coal-fired 300MW, 600MW, 1000MW Turbo analyzed using KEDTB del Taba flow measurement points and parameters related; 300MW boiler and steam turbine units; use KEDTB del Taba integrated sensor solutions, selection , pressure and differential pressure loss calculation; and other products in the pressure loss and other aspects of comparison.
One. With the development of China's modernization, businesses growing demand for electricity, the country's installed capacity increased rapidly. This article focuses on the thermal power, the national installed capacity of 1987 100GW, 1995 years 200GW, 2004 has reached 300GW. According to the National Development and Reform Commission's report, planned for 2010 will reach 540GW, 2020 years 900GW, will increase by 30GW.
Increase in capacity at the same time, the most notable is the variety of highly efficient new technologies, new technology constantly being put into use. Supercritical units, steam combined cycle gas turbine, positive pressure circulating fluidized bed （PFBC）, circulating fluidized bed combined cycle （PFBC-CC）, Integrated Gasification Combined Cycle （IGCC）, and the boiler pressure pulverized coal combustion technology combined cycle used in the context of different research and began to use extensively. Its main purpose is to improve plant efficiency. 1957 first put into operation in the United States of supercritical efficiency up to 40 ~ 47%, there are nearly supercritical unit in the world of normal operation, the largest single capacity of 1300MW, and the sub-critical unit cost approach.
Sense of environmental protection and energy saving, power industry is a major user of coal, 45% of our coal is used for power generation, coal consumption per kilowatt-hour up to 400 grams （90 412 early g / kW） than developed countries High 70 to 80 g / kW. Only by improving the turbine operating temperature, such as PFBC-CC, in the 850 ~ 900 ° C, which can inhibit the formation of Nox and improve efficiency to 40%. Achieve high efficiency and low purposes. Meanwhile, the dust produced from burning coal is one of the major sources of pollution.
Overview of advanced technology, high-precision measurement and control needs to steam turbine and boiler needs in a variety of coal, water, wind and steam to conduct a comprehensive measure is to ensure that the necessary conditions for the implementation of various processes. Some do not need to measure the amount of past, now must be considered, such as the various aspects of the main steam, increasing the amount of the main aspects of the steam.
II. As a large variety of flow measurement points means coal thermal power plant, water supply in different ways, may be used to heating units, and the ash / slag / gypsum （FGD by-products） the need for comprehensive utilization and other factors. Makes the thermal power plant complex and varied process systems. Therefore, given universal significance, such as flow measurement program is unrealistic. Here are just on the general description, then give KEDTB del Taba for the flow measurement solutions.
（1） oil / gas flow measurement:
Fuel oil and gas as boiler fuel or start the ignition with the Lord. Current coal-fired units start ignition oil （light oil）, usually using mass flow meter or the wheel （drum） type. This part can use the plug-in differential pressure flow meter, KEDTB del Taba-owned power plant has been in many widely used. （Due to great differences in diameter of the pipe, where the design is simple, just for reference）.
The main process parameters:
Fuel: Mechanical atomization time: room temperature, 3Mpa; 30t / h, 100 * 4.5mm （1-1）
When atomized media: room temperature, 1.5Mpa; 15 t / h; 100 * 4.5mm （1-2）
（2） Cooling water flow measurement:
Including the main power plant cooling water, auxiliary cooling water cooler, part of the process steam used in cooling water systems, such as cooling water, open and closed cooling water, most of the commonly used river power plants, river water （such as the Yangtze River , Pearl River）, or water, because it uses a public social resources, the need for measurement. Usually relatively large diameter. If a power plant cooling water used in Wuhan Yangtze River.
Pipe diameter ¢ 1820 * 10mm, normal temperature, medium pressure 0.2Mpa, maximum flow 24372t / h. （2-1） （3） The system of water: usually clean water, much better than the quality of tap water is compley plug-in differential pressure flow meter can be used
（A） In addition to salt water after chemical treatment: room temperature, 0.5Mpa, 60t / h, 150x4mm （3-1）
（B） units make up water: room temperature, 0.5Mpa, 50t / h, 150x4mm （3-2）
（C） boiler feed water: 300 ° C, 18.0Mpa, 1000t / h （3-3）
（D） reduction of water temperature （superheated steam I / II by warm water）: 215 ° C, 14Mpa, 12t / h, 22 * ??3mm （3-4）
（E） Less reheat steam temperature and quantity of incidents: 200 ° C, 6Mpa, 10t / h （3-5）
（F） water temperature reducing bypass: high pressure, 300 ° C, 18.0Mpa, 200t / h （3-6）
When low-voltage, 200 ° C, 6.0Mpa, 80t / h （3-7）
（G） to the pump outlet flow: 180 ° C, 18Mpa, 500t / h （3-8）
（H） condensation of water flow: 100 ° C less, 2.0Mpa, 1000t / h （3-9） （4） steam system
（A） main steam: the accurate measurement of the main steam flow to meet the unit test and control requirements. Usually 300MW/600MW unit is the main steam flow measurement by indirect methods, measuring turbine control stage pressure （Po for the Q main steam pressure, P1 to adjust the level of pressure）, provided by the manufacturer under the master mathematical model for the derivation of steam to do functional strength E = f （Q main steam） = f （Po, P1）. So the main steam flow measurement （calculated） accuracy will depend on the accuracy and precision of the mathematical model and the sensor accuracy, the current measurement unit is only suitable for part load range, which is calculated （measurement） is not satisfied with the accuracy required to run . There is now such as KEDTB del Taba （high pressure） flow measurement devices, can be measured directly. It has been widely used in Europe and America, since 1996, already has nearly 900 more （high pressure） application examples. For example:
Use year / month username diameter / wall thickness of pressure temperature flow
1996/07: Preussen Elektra: 232/28mm 25.5Mpa 550 ° C 450t / h
1996/06: GKK Kiel GmbH: 233/37mm 27.6Mpa 545 ° C 500t / h
1999/01: L & C Steinmuller: 285/40mm 29.8 Mpa 486 ° C 900 t / h
2001/04 Babcock GmbH: 265/25mm 16.6 Mpa 535 ° C 500 t / h
2004/05 Enercity 240/28 21.5 Mpa 545 ° C 486 t / h
......
For domestic users, there is a cognitive process, it really is a safe, effective and economical solution. High temperature high pressure steam, temperature and pressure in the high-pressure natural gas or liquid （water） can be used del Taba high temperature and pressure probes.
Calculations show that the same parameters of the main steam flow measurement, using the nozzle will make the unit efficiency decreased from 0.25 to 0.3%. So it is necessary to consider the use of plug-in probe KEDTB del Taba, although the amount of small, but significant. Many domestic power plants to be measured the flow of these points, but worried that such a high temperature and pressure used in the security, reliability, worry about the price too high. Using the nozzle, pressure loss and too large, has been in a hovering state. From the large number of analysis / comparison data should be seen, the pressure probe into the loss of only the standard orifice 5 to 10%, 20% of the nozzle, so the use of plug-in sensor will give a huge run enterprises to reduce costs. Usually run 30 to 60 days （in the above conditions） operating cost savings is enough to buy a set of probes. Looking KENER performance, it can allow people to safely use.
IV. Solution: KEDTB del Taba average rate of integration of the probe according to different media and the corresponding deformation parameters are given and solutions to meet different requirements and installation. Del Taba four of five models can be widely used in power plants. DF25: typically used for 80? 3000mm pipe liquid （water, oil）, gas （all gas, humidity） and steam;
DF25HD: 80-1000mm pipe typically used for high temperature and high pressure steam （such asmain steam）, or high pressure in the temperature of the liquid （such as by warm water, etc.）, or low-temperature high-pressure gas （such as natural gas, etc.）;
DF10M / HD: typically used for 20? 100mm pipe liquid, gas or steam measurement can also be used in areas of high temperature and pressure;
DF50: typically used for 1 - 15 meters of large diameter air or gas measurement sensor measurement accuracy better than 1%, 0.5%, 0.2% and 0.1% repeatability. For more selection, please contact Kener.
Five. Analysis and comparison of other products and
1 Products
As we all know, traffic types and a wide variety of products, differential pressure, electromagnetic, vortex type, float, ultrasonic, Coriolis-type positive displacement and so on. Currently the most widely used number of differential pressure. The differential pressure of the mainstream products are throttle （orifice, venturi tube or nozzle and other products） and the average rate. Market, extensive use of these standardized products and non-standardized products. Its main feature is the use of extensive, can be used for all single-phase fluid and part of mixed phase flow; standardized throttling device can be used directly without calibration, there are a variety of continuous improvement of international standards support, such as ISO-5167 （1980/1991 / 1998/2003）, GB - 1932 （nozzle）, the use of the world, nearly a million samples. Major laboratory test samples collected tens of thousands, the establishment of the very comprehensive database. Constantly updated standards, a more accurate system model out to do the theory and use of accumulated data, thus greatly improving the measurement accuracy. So reason to say that under the new standards created by the orifice is more flexible and very high precision. Followed by the easy to copy, simple, solid, stable performance, reliable, long duration, low prices. Since the 20th century, 80 years, standard and non-standard cutting devices flow measurement in the world accounting for 50 to 60%, accounting for millions every year, the amount of 30%; in China accounted for 35 ~ 42%, accounting for 6 to 7 million per year Taiwan. The main disadvantage of throttle products:
（1） measurement repeatability and accuracy is medium level, but difficult to improve accuracy;
（2） a narrow range of degrees, the general can only be 3:1 to 4:1;
（3） on-site installation conditions more demanding long straight sections （referring to plates, nozzles）, generally difficult to meet;
（4） test pieces with the differential pressure between the display instrument cited as the weak link in the pipeline pressure, easy to leak, blockage, freezing and signal distortion problems.
（5） large pressure loss （ie plates, nozzles）. In recent years, many new improvements, mainly in the lower pressure loss and shorten the straight pipe and the throttle with the transmitter integration. Average rate is also a principle of differential pressure throttling device, according to incomplete statistics and reports, nearly 30 years, more than 200 million put into practical use. 10 years and this has increased significantly. Its main feature is simple to install and maintain （insert type）, high accuracy （better than 1%）, good repeatability （0.1%）, the most prominent advantage is that pressure loss is small, usually only the standard plate of 5% to 10%, standard nozzles 10% to 20%; while the long term to maintain accuracy. Straight pipe it needs much shorter than the throttle. On the other hand, the pressure loss is small at the same time, differential pressure is relatively small （in terms of equivalent orifice）, especially when a small flow large diameter. Second, the average velocity before and after the information was taken from a number of rods in the holes, because there are holes, they will naturally be blocked or foreign bodies stuck. Third, the average rate is determined by measuring the velocity of a diameter to the flow line （specifically, a number of points of the line） instead of cross flow, and different diameter flow line is not exactly the same （ Unless it is in position enough straight pipe）, so there is inappropriate if the installation position and direction will lead to invalid measurement or no measurement accuracy, so choose the installation location is to ensure that the proper use of the important factors. Nearly 10 years, the average rate of cross-section technology and technology made great progress in opening the previous sample of the many deficiencies with the use of means to increase and the introduction of high-tech research, launched the probe in recent years than the more mature products 10 years ago . KEDTB del Taba high side and low side of the probe are compley symmetrical, the same number of holes, hole diameter of 8mm, the distance between the holes is not the so-called complete log, but according to the diameter, the media and the main process parameters and other factors to determine the hole distance. Hole is not on the number of holes 2,3 tradition, according to a combination of factors, or there will be 4 on 5 pairs of holes, or even 6 on the hole, these are not a lot of imitators eager to start the core technology. Del Taba continuously reform in this decade, updating and development, has emerged in many ways superior characteristics. Its choice of site installation and installation requirements than other similar products to rigorous and more complete set of systems and databases as a support. Differential output in the form of nearly a hundred species, to ensure that meet the user's special mining and special needs. Diameter range from 3 millimeters to 15 meters; high temperature and pressure probes （1.4828, X15CrNiSi20-12, operating temperature up to 1040 degrees） can work at 650 degrees, 28 mpa steam; can choose to 1.4539 （A904 alloy, X1NiCrMoCu25-20-5 ） and H C4, work with the SO, SO2 in the flue gas or acid and alkali media. （2） Comparison of straight pipe （nozzle orifice and the data from the IS05167-1999）
Between the plate and baffles the required length of straight pipe （no flow regulator） （the value of the diameter D expressed as a multiple） of which: A column length is the "zero additional uncertainty," the; B column length refers to the "0.5% additional uncertainty," the.
KEDTB del Taba straight pipe requirements:
3. Comparison of pressure loss
The following results are based on FlowCalc32 software, according to pipeline processing parameters and calculation of various differential throttling device and pressure drop, KEDTB del Taba calculations are based on DeltaCalc4.3, their working conditions and FlowCalc32 identical.
Some conclusions:
（1） Standard Angle Flange access pressure and differential pressure and pressure drop similar, relatively large （due to length, did not show the calculation results to take pressure flange）;
（2） Venturi nozzle in the pressure loss on a relatively large improvement;
（3） in the temperature / pressure / flow is relatively small case, KEDTB del Taba pressure loss and improved venturi nozzle is no essential difference; at large, especially the steam, there are 10-fold difference. 4. Operating cost analysis
Computing power （WP） in the usual way:
WP = Q x PL / η
Where: Q: volume flow conditions （from the above table, m3 / s）; PL: the maximum pressure loss （from the above table, kpa）; η: efficiency coefficient （taking 80%）
If you provide a standard condition （or mass） flow （Qn）, Q = Qn x ρn （standard condition density） / ρb （condition density）
ρn （standard condition density）: Water: 1000kg/Nm3 （0 ℃, 101.325kpa）
ρn （standard condition density）: Air: 1.2929 kg/Nm3
ρn （standard condition density）: Steam: 1000kg/Nm3 （the liquid）
Ex.1:, ρb （water） = 998.254 kg/m3; （20 ℃ / 0.2mpa）
Q1 = 200x1000/998.254/3600/0.8 = 0.0698; WP = Q1 x PL = 0.0698 x PL
WP1 = 1.047 KW （angle receives pressure）; WP2 = 0.0448 KW （Venturi nozzle）; WP3 = 0.0264 KW
On an annual basis: KEDTB del Taba access than the angle of pressure to save energy 8940 KW / year, compared with Venturi nozzle reduce energy consumption 161.2 KW / year.
Ex2. Ρb （water） = 731.182 kg/m3; Q2 = 0.4749; WP = Q2 x PL = 0.4749x PL;
WP1 = 46.9153KW （angle receives pressure）; WP2 = 14.3548 KW （Venturi nozzle）; WP3 = 0.7495 KW
On an annual basis, KEDTB del Taba pressure than the angle of access to save 404412 KW / year, saving more than Venturi nozzle 119182.4 KW / year.
Ex.4: ρb （steam） = 43.524kg/m3; Q4 = 3.1911; WP = 3.1911 x PL;
WP1 = 841.6686 KW （angle receives pressure）; WP2 = 32.7056 KW （Venturi nozzle）;
WP3 = 260.61 （ISO1932 nozzle）; WP4 = 3.3985KW （del Taba）
On an annual basis: KEDTB del Taba pressure than the angle of access savings 7.3432x106 KW / year, saving more than Venturi nozzle 2.5673x105 KW / year energy consumption savings compared with ISO1932 nozzle 2.5673x105 KW / years. Ex.5: ρb （steam ） = 72., 345kg/m3; Q5 = 9.5991; WP = 9.5991 x PL
WP1 = 44773.9844KW （angle receives pressure）; WP2 = 1651.5252KW （Venturi nozzle）;
WP3 = 13160.2221 （ISO1932 nozzle）; WP4 = 155.1714KW （del Taba）
On an annual basis: KEDTB del Taba pressure than the angle of access savings 3.9086x108 KW / year, saving more than Venturi nozzle 1.3108x107 KW / year, saving more than ISO1932 nozzle 13005.1KW / year. Some use of integrated, especially in high temperature and high pressure steam, using KEDTB del Taba will bring huge economic benefits, with minimal pressure drop venturi nozzle has 10 times the difference. Meanwhile, the pressure loss also means that wear and long life; contrary wear big, short life. In the high temperature and pressure conditions, KEDTB del Taba probe material is 1.4828, its materials and manufacturing processes to ensure the design life of up to 200,000 hours, equivalent to 22.8 years, is bearing almost all the other products if possible and achievable.
VI. Comparison of installation
Most of the average rate is the plug-in mode, installation and maintenance simple and quick installation of a probe generally takes an hour or so. You can also implement an online plug-type line installation, on-line maintenance. This is a throttling device in general not comparable.
VII. Conclusion
The rapid development of thermal power units, need safe, reliable and accurate flow measurement, KEDTB del Taba average rate provides a complete set of solutions, products can not be involved in the general areas, such as 20mm diameter, 28mpa, 215 degrees reduction in warm water; 400mm diameter, 28mpa, 600 degree superheated steam; more than 10 m diameter of the flue gas. It is an energy-saving products at the same time, can greatly reduce operating costs, to create more economic benefits. This technology and product design and power plant industries become more and more popular.
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