Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is developed in accordance with the rules given in GB/T 1.1-2009 Directives for standardization - Part 1: Structure and drafting of standards.
Attention is drawn to the possibility that some of the elements of this standard may be the subject of patent rights. The issuing authority of this standard shall not be held responsible for identifying any or all such patent rights.
This standard replaces DL/T 468-2004 Guide on type selection and application for power boiler fans. In addition to editorial changes, the following main technical changes have been made with respect to DL/T 468-2004:
——The definitions of forced draft fan and induced draft fan in clause 3 have been modified;
——The definition of stall safety factor of axial flow fan has been added in clause 3;
——The definitions of base flow, base pressure and test block have been added in clause 3;
——The title of clause 4 has been changed as design requirements of fan;
——The relevant contents on the requirements of fan manufacturing in clause 4 have been deleted;
——The title of clause 5 has been changed as type selection of fans;
——The requirements for original data ought to be provided for fan selection have been given in clause 5;
——The requirements on the selection of fan rotating speed in clause 5 have been modified;
——The requirements on selection of number of fans in clause 5 have been modified;
——The requirements on fan adjustment method in clause 5 have been modified;
——The requirements on stall safety factor of axial flow fan in clause have been modified;
——The clause 6 "Installation of fan" in the original standard has been deleted;
——The serial number of clause 7 of the original standard has been revised to 6, and the serial numbers of subsequent clauses and subclauses has been revised accordingly;
——The requirements on operating parameter control in clause 6 “Fan operation” have been modified.
This standard was proposed by the China Electricity Council.
This standard is under the jurisdiction of DL/TC 08 Technical Committee on Power Station Boiler of Standardization Administration of Power Industry.
The previous editions of this standard are as follows:
——DL/T 468-1992;
——DL/T 468-2004.
Any comments or suggestions during the implementation of this standard may be fed back to the Standardization Center of the China Electricity Council (No.1, 2nd Lane, Baiguang Road, Beijing, 100761, China).
Guide to selection and application of boiler fans for power plants
1 Scope
This standard specifies the basic requirements for the selection and application of boiler fans for power plants as well as for arrangement and design of inlet and outlet pipelines of fans.
This standard is applicable to forced draft fan, induced draft fan, primary fan, exhauster (pulverized coal fan), flue-gas recirculating fan, booster fan of flue gas desulfurization device and seal air fan for coal mill. Reference may be made to this standard for other small fans for boilers, such as ignition fan, cooling fan and dilution fan of SCR denitration system.
This standard is not applicable to oxidation fans of desulfurization systems and high-pressure fluidization fans of circulating fluidized bed boilers.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 1236 Industrial fans - Performance testing using standardized airways
GB/T 2888 Methods of noise measurement for fans blowers compressors and roots blowers
GB/T 3235 Basic types sizes parameters and characteristics curve of fans
GB/T 3947 Acoustical terminology
GB/T 10178 Industrial fans - Performance testing in situ
GB/T 17774 Industrial fans - Dimensions
GB/T 19075 Industrial fans - Vocabulary and definitions of categories
GB 50660 Code for design of fossil fired power plant
DL/T 469 Fans performance testing in situ for power boiler
DL/T 5121 Technical code for design of thermal power plant air & flue gas ducts/ raw coal & pulverized coal piping
DL/T 5145 Technical code for design and calculations of coal pulverizing system of fossil-fired power plant
DL 5190.2 Technical specification for thermal power erection and construction - Part 2: boiler unit
JB/T 4358 Centrifugal fan for boiler of power station
JB/T 4362 Power station axial fans
JB/T 6891 Technical specification for silencer of fan
JB/T 8689 Fan vibration detection and its limited value
JB/T 8690 Industrial fans noise limited value
JB/T 8822 High temperature centrifugal fan - Specification
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
forced draft fan; FDF
fan that supplies air needed for boiler fuel combustion and is arranged in front of the boiler air preheater, which sends the air sucked from the atmosphere to the air preheater to heat it to the design temperature, then, for direct-fired pulverizing system, sends the air directly into the boiler furnace through the burner as the secondary air of the boiler and, for the middle storage pulverizing system, sends one part of the air directly into the boiler furnace through the burner as the secondary air of the boiler and the other part of the air into pulverized coal preparation system as desiccant or into furnace as primary air conveying the pulverized coal through burner (exhaust gas pulverized coal feeding system) or into furnace as tertiary air through the burner (hot air pulverized coal feeding system); large boilers adopting medium speed coal mills or double-inlet and double-outlet low speed coal mill positive pressure direct-fired pulverizing system are all equipped with high-pressure cold primary fans which either draw air from the outlet of the forced draft fan which supplies the total air volume required by the boiler or draw air from the atmosphere, in which case the forced draft fan only supplies the secondary air to the boiler, which is also called the secondary air fan.
3.2
induced draft fan; IDF
fan installed behind the boiler dust remover, sucking out the boiler combustion products (flue gas) from the boiler tail and sending to the booster fan of the desulfurization system after passing through the denitration system and dust removal system and, after the flue gas pressure is raised by the booster fan, discharging the flue gas into the atmosphere from the chimney through desulfurization system, also known as the suction fan, which shall overcome the resistance of the whole flue gas system from boiler furnace to chimney outlet if there is no booster fan, in which case it is commonly known as 2-in-1 induced draft fan
?
3.3
primary fan; PF
fan that supplies primary air needed for boiler fuel combustion, which is classified by its installation position in the system into cold primary fan and hot primary fan
3.4
cold primary fan
primary fan installed in front of the boiler air preheater and sending the air sucked from the atmosphere or from the outlet cold air duct of the forced draft fan into pulverizing system after being heated by the air preheater
3.5
hot primary fan
primary fan which is installed behind the boiler air preheater and sends the air heated by the boiler air preheater to direct-fired pulverizing system or sends only the pulverized coal to the boiler
3.6
exhauster
fan for conveying desiccant and pulverized coal in pulverized coal preparation system, which is mainly used in the middle storage pulverizing system and installed behind the fine powder separator, also known as pulverized coal fan
3.7
flue-gas recirculating fan
fan sucking out part of the flue gas from the backside of the economizer and front of the air preheater, the lower part of furnace, the backside of the electrical precipitator, the outlet of induced draft fan, etc., and delivering to the boiler cold ash hopper or the upper part of furnace to adjust the boiler steam temperature or delivering to the coal mill inlet to adjust the temperature or oxygen content
?
3.8
flue gas desulfurization booster fan
fan set behind the induced draft fan to overcome the resistance of the flue gas desulfurization system
3.9
seal air fan
fan for supplying sealing air for medium speed coal mill, double-inlet and double-outlet low speed coal mill and coal feeder, which may suck air directly from the atmosphere, and may also suck air from the outlet pipeline of forced draft fan or primary fan
3.10
inlet plane and inlet area of fan
A1
fan inlet plane referring to the surface bounded by the upstream extremity of the air moving device, and generally, fan inlet area referring to the total through-flow area of the inlet (flange) plane of the enclosure (or the inlet box in the case of fans with inlet box)
3.11
outlet plane and outlet area of fan
A2
fan outlet plane referring to the surface bounded by the downstream extremity of the air moving device, and generally, fan outlet area referring to the total area of the plane of the enclosure outlet (flange)
3.12
stall safety factor of axial flow fans
vector indicating the stall margin of axial flow fan in this standard, which is expressed by k (see 5.4.4 of this standard)
?
3.13
fan system
system consisting of fan, equipment as well as a series of air duct, pipe, bend and branch pipe on the conveying path for conveying air or gas from one or more places to another one or more places
3.14
system characteristic curves
diagram for resistance versus volumetric flow characteristics of a system
3.15
system effect
influence of system layout on fan performance which is affected by the inlet and outlet connection pipes which, if connected improperly, together with uneven airflow at the inlet and vortex at the inlet of the fan, will change the aerodynamic characteristics of the fan and reduce the performance of the fan
3.16
system effect loss
reduction of fan pressure caused by system effect
3.17
base flow
fan flow required for operation at the boiler maximum continuous rating calculated according to the design coal type
3.18
base pressure
total resistance of fan system when operating at the boiler maximum continuous rating calculated according to the design coal type
?
3.19
test block
maximum continuous operation condition of the fan required for type selection
3.20
specific A sound level; LSA
A sound level at unit flow rate and unit fan pressure, which shall be calculated using Equation (1):
(1)
where,
LSA——the specific A sound level, dB(A);
LA——the A sound level, dB (A);
qV——the volumetric flow rate, m3/min;
pF——the fan pressure, Pa.
4 Design requirements of fans
4.1 General requirements
4.1.1 The design of fans shall meet the requirements of GB/T 3235 and GB/T 17774.
4.1.2 The design and manufacture of centrifugal fans shall meet those specified in JB/T 4358.
4.1.3 The design and manufacture of axial flow fans shall meet those specified in JB/T 4362.
?
4.1.4 The natural vibration frequency of the fan impeller (or blade) shall not be the same as the rotating speed frequency of the impeller and the frequency multiplication less than 10 times of it, or other dangerous frequencies, such as the blade passing frequency, i.e., the product of the rotating speed (for fans with rotating speed regulation, it refers to all the rotating speeds within the regulation range) and the number of blades (includes rotor blades and front and rear adjustable or guide blades for impellers), and high amplitude air motion frequency.
4.1.5 For fans with variable speed adjustment, calculations on torsional vibration of shafting shall be conducted to prevent it from occurring.
4.1.6 The fan shall be equipped with necessary automatic alarm and protection devices (such as those for bearing temperature, fuel cut-off, vibration, and stall flutter of axial flow fan).
4.1.7 Fans with air intake from the atmosphere (such as forced draft fans and primary fans) shall be equipped with an air inlet silencer that is designed and manufactured in accordance with JB/T 6891.
4.2 Design requirements
4.2.1 For hot primary fan, the design inlet air temperature shall be 250℃, the maximum allowable inlet air temperature shall not exceed 400℃ and the airborne dust concentration shall not exceed 100mg/m3. The design of it shall comply with those specified in JB/T 8822.
4.2.2 The flue gas system upstream of the induced draft fan is equipped with a low-temperature economizer system, and the inlet temperature of the induced draft fan is around 90℃, at which the flue gas is corrosive, so reliable anti-corrosion measures shall be taken in the flow path of the fan.
4.2.3 The exhauster (pulverized coal fan) is designed to convey air containing pulverized coal. The pulverized coal content shall not be greater than 80g/m3 for the exhaust gas from middle storage pulverizing system of low speed coal mill, and it shall be 300g/m3~800g/m3 for negative-pressure direct-fired pulverizing system. The design inlet gas temperature and the maximum allowable inlet gas temperature shall be 70℃ and 150℃, respectively. The enclosure and impeller shall be protected from wear according to the wear characteristics of the coal (see DL/T 5145 for the wear indexes), and the service life of the impeller shall not be less than 8,000h.
?
4.2.4 The flue-gas recirculating fan is designed to convey hot flue gas with an ash content no greater than 20g/m3 and a temperature no higher than 400℃. The volute and impeller shall be properly protected from wear. The bearings shall be equipped with special heat insulation and cooling devices, and their service life shall not be less than 8,000h. Flue-gas recirculating fan without speed adjusting device shall be equipped with a turning device.
4.2.5 Noise countermeasures shall be taken in the design of seal air fan. Seal air fans with direct air intake from the atmosphere shall be equipped with inlet filters and inlet and outlet silencers.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Design requirements of fans
5 Type selection of fans
6 Fan operation
7 Fan noise
8 Test and acceptance of fan
9 Fan system design
Annex A (Informative) Necessary information on selection of fan
Annex B (Informative) Necessary information for evaluation of fan design
Annex C (Informative) Calculation of standard density of humid air
電站鍋爐風(fēng)機(jī)選型和使用導(dǎo)則
1 范圍
本標(biāo)準(zhǔn)規(guī)定了電站鍋爐風(fēng)機(jī)的選型、使用及風(fēng)機(jī)進(jìn)出口管道布置設(shè)計(jì)的基本要求。
本標(biāo)準(zhǔn)適用于電站鍋爐的送風(fēng)機(jī)、引風(fēng)機(jī)、一次風(fēng)機(jī)、排粉風(fēng)機(jī)(煤粉風(fēng)機(jī))、煙氣再循環(huán)風(fēng)機(jī)、煙氣脫硫裝置的增壓風(fēng)機(jī)和磨煤機(jī)用的密封風(fēng)機(jī)。其他供鍋爐用的小型風(fēng)機(jī)如點(diǎn)火風(fēng)機(jī)、冷卻風(fēng)機(jī)、SCR脫硝系統(tǒng)的稀釋風(fēng)機(jī)等可參照使用。
本標(biāo)準(zhǔn)不適用于脫硫系統(tǒng)的氧化風(fēng)機(jī)和循環(huán)流化床鍋爐的高壓流化風(fēng)機(jī)。
2 規(guī)范性引用文件
下列文件對(duì)于本文件的應(yīng)用是必不可少的。凡是注日期的引用文件，僅注日期的版本適用于本文件。凡是不注日期的引用文件，其最新版本(包括所有的修改單)適用于本文件。
GB／T 1236 工業(yè)通風(fēng)機(jī) 用標(biāo)準(zhǔn)化風(fēng)道進(jìn)行性能試驗(yàn)
GB／T 2888 風(fēng)機(jī)和羅茨鼓風(fēng)機(jī)噪聲測(cè)量方法
GB／T 3235 通風(fēng)機(jī)基本型式、尺寸參數(shù)及性能曲線
GB／T 3947 聲學(xué)名詞術(shù)語
GB／T 10178 工業(yè)通風(fēng)機(jī) 現(xiàn)場(chǎng)性能試驗(yàn)
GB／T 17774 工業(yè)通風(fēng)機(jī) 尺寸
GB／T 19075 工業(yè)通風(fēng)機(jī) 詞匯及種類定義
GB 50660 大中型火力發(fā)電廠設(shè)計(jì)規(guī)范
DL／T 469 電站鍋爐風(fēng)機(jī)現(xiàn)場(chǎng)性能試驗(yàn)
DL／T5121 火力發(fā)電廠煙風(fēng)煤粉管道設(shè)計(jì)技術(shù)規(guī)程
DL／T5145 火力發(fā)電廠制粉系統(tǒng)設(shè)計(jì)計(jì)算技術(shù)規(guī)定
DL5190.2 電力建設(shè)施工技術(shù)規(guī)范 第2部分：鍋爐機(jī)組
JB／T 4358 電站鍋爐離心式通風(fēng)機(jī)
JB／T 4362 電站軸流式通風(fēng)機(jī)
JB／T 6891 風(fēng)機(jī)用消聲器技術(shù)條件
JB／T 8689 通風(fēng)機(jī)振動(dòng)檢測(cè)及其限值
JB／T 8690 工業(yè)通風(fēng)機(jī) 噪聲限值
JB／T 8822 高溫離心通風(fēng)機(jī)技術(shù)條件
3 術(shù)語和定義
下列術(shù)語和定義適用于本文件。
3.1
送風(fēng)機(jī)forced draft fan；FDF
供給鍋爐燃料燃燒所需空氣的風(fēng)機(jī)。布置在鍋爐空氣預(yù)熱器之前。將從大氣中吸入的空氣送入空氣預(yù)熱器，加熱到設(shè)計(jì)溫度后，對(duì)于直吹式制粉系統(tǒng)，作為鍋爐的二次風(fēng)，直接經(jīng)燃燒器送入鍋爐爐膛。對(duì)于中間倉(cāng)儲(chǔ)式制粉系統(tǒng)，則一部分作為鍋爐的二次風(fēng)，直接經(jīng)燃燒器送入鍋爐爐膛；另一部分進(jìn)入煤粉制備系統(tǒng)作為干燥劑，或作為一次風(fēng)輸送煤粉經(jīng)燃燒器送入爐膛(乏氣送粉系統(tǒng))，或作為三次風(fēng)經(jīng)燃燒器送入爐膛(熱風(fēng)送粉系統(tǒng))。大型鍋爐采用中速磨煤機(jī)或雙進(jìn)雙出鋼球磨煤機(jī)正壓直吹式制粉系統(tǒng)，均配有高壓冷一次風(fēng)機(jī)。一次風(fēng)機(jī)有從送風(fēng)機(jī)出口吸取空氣的，則送風(fēng)機(jī)供給鍋爐所需的總風(fēng)量；也有專門從大氣吸入空氣的，此時(shí)送風(fēng)機(jī)只供給鍋爐的二次風(fēng)，亦稱二次風(fēng)機(jī)。
3.2
引風(fēng)機(jī) induced draft fan；IDF
安裝在鍋爐除塵器之后，將鍋爐燃燒產(chǎn)物(煙氣)從鍋爐尾部吸出并經(jīng)脫硝系統(tǒng)、除塵系統(tǒng)后送入脫硫系統(tǒng)的增壓風(fēng)機(jī)，提升壓力后再經(jīng)脫硫系統(tǒng)由煙囪排入大氣的風(fēng)機(jī)，又稱吸風(fēng)機(jī)。如不設(shè)增壓風(fēng)機(jī)，則從鍋爐爐膛到煙囪出口整個(gè)煙氣系統(tǒng)的阻力均由引風(fēng)機(jī)克服(俗稱二合一引風(fēng)機(jī))。
3.3
一次風(fēng)機(jī) primary fan：PF
供給鍋爐燃料燃燒所需一次空氣的風(fēng)機(jī)。按其在系統(tǒng)中的安裝位置，有冷一次風(fēng)機(jī)和熱一次風(fēng)機(jī)之分。
3.4
冷一次風(fēng)機(jī) cold primary fan
安裝在鍋爐空氣預(yù)熱器之前，將從大氣或從送風(fēng)機(jī)出口冷風(fēng)道抽吸的空氣經(jīng)空氣預(yù)熱器加熱后輸送至制粉系統(tǒng)的一次風(fēng)機(jī)。
3.5
熱一次風(fēng)機(jī) hot primary fan
安裝在鍋爐空氣預(yù)熱器之后，輸送經(jīng)過鍋爐空氣預(yù)熱器加熱后的熱空氣至直吹式制粉系統(tǒng)或僅輸送煤粉至鍋爐的一次風(fēng)機(jī)。
3.6
排粉風(fēng)機(jī) exhauster
煤粉制備系統(tǒng)中用以輸送干燥劑和煤粉的風(fēng)機(jī)。主要用于中間儲(chǔ)倉(cāng)式制粉系統(tǒng)中，安裝在細(xì)粉分離器之后。也稱煤粉風(fēng)機(jī)。
3.7
煙氣再循環(huán)風(fēng)機(jī) flue-gas recirculating fan
把一部分煙氣從省煤器后空氣預(yù)熱器前、爐膛下部、電除塵器后、引風(fēng)機(jī)出口等處抽出，并輸送至鍋爐冷灰斗或爐膛上部，用以調(diào)節(jié)鍋爐蒸汽溫度；或送至磨煤機(jī)入口用以調(diào)節(jié)溫度或含氧量的風(fēng)機(jī)。
3.8
煙氣脫硫增壓風(fēng)機(jī) flue gas desulfurization booster fan
在引風(fēng)機(jī)后設(shè)置的用以克服煙氣脫硫系統(tǒng)阻力的風(fēng)機(jī)。
3.9
密封風(fēng)機(jī) seal air fan
供給中速磨煤機(jī)、雙進(jìn)雙出鋼球磨煤機(jī)和給煤機(jī)等裝置密封用空氣的風(fēng)機(jī)。密封風(fēng)機(jī)可直接從大氣吸入空氣，也可從送風(fēng)機(jī)或一次風(fēng)機(jī)出口管道內(nèi)吸取空氣。
3.10
風(fēng)機(jī)進(jìn)口平面和進(jìn)口面積 inlet plane and inlet area of fan
A1
取空氣輸送裝置上游末端的界面為風(fēng)機(jī)進(jìn)口平面。通常，取機(jī)殼(帶進(jìn)氣箱的風(fēng)機(jī)取進(jìn)氣箱)進(jìn)口(法蘭)平面的通流總面積作為風(fēng)機(jī)進(jìn)口面積。
3.11
風(fēng)機(jī)出口平面和出口面積 outlet plane and outlet area of fan
A2
取空氣輸送裝置下游段始端的界面為風(fēng)機(jī)出口平面。通常，取機(jī)殼出口(法蘭)平面的總面積作為風(fēng)機(jī)出口面積。
3.12
軸流式風(fēng)機(jī)失速安全系數(shù) stall safety factor of axial flow fans
本標(biāo)準(zhǔn)表示軸流式風(fēng)機(jī)失速裕度的量，用k表示(見本標(biāo)準(zhǔn)5.4.4)。
3.13
風(fēng)機(jī)系統(tǒng) fan system
為從一處或多處向另一處或多處輸送空氣或氣體而由風(fēng)機(jī)和輸送路徑上的各設(shè)備及一系列風(fēng)筒、管路、彎管和支管所組成的系統(tǒng)。
3.14
系統(tǒng)特性曲線 system characteristic curves
某個(gè)系統(tǒng)的阻力對(duì)容積流量特性的圖解。
3.15
系統(tǒng)效應(yīng) system effect
系統(tǒng)布置對(duì)風(fēng)機(jī)性能的影響。風(fēng)機(jī)的性能受其進(jìn)、出口連接管道的影響。如果連接不當(dāng)、進(jìn)口氣流不均勻，以及風(fēng)機(jī)進(jìn)口處存在渦流，則將改變風(fēng)機(jī)的空氣動(dòng)力特性，降低風(fēng)機(jī)的性能。
3.16
系統(tǒng)效應(yīng)損失 system effect loss
由系統(tǒng)效應(yīng)引起的風(fēng)機(jī)壓力的降低。
3.17
基本風(fēng)量 base flow
按設(shè)計(jì)煤種計(jì)算的鍋爐最大連續(xù)蒸發(fā)量運(yùn)行所需的風(fēng)機(jī)流量。
3.18
基本壓力 base pressure
按設(shè)計(jì)煤種計(jì)算的鍋爐最大連續(xù)蒸發(fā)量運(yùn)行時(shí)的風(fēng)機(jī)系統(tǒng)總阻力。
3.19
選型工況(TB工況) test block
選型要求風(fēng)機(jī)應(yīng)達(dá)到的最大連續(xù)運(yùn)行工況。
3.20
比A聲級(jí) specific A sound level；LSA
單位流量、單位風(fēng)機(jī)壓力時(shí)的A聲級(jí)。比A聲級(jí)按式(1)計(jì)算：
(1)
式中：
LSA——比A聲級(jí)，dB(A)；
LA——A聲級(jí)，dB(A)；
qV——體積流量，m3／min；
pF——風(fēng)機(jī)壓力，Pa。
4 風(fēng)機(jī)的設(shè)計(jì)要求
4.1 總體要求
4.1.1 風(fēng)機(jī)的設(shè)計(jì)應(yīng)符合GB／T 3235及GB／T 17774的要求。
4.1.2 離心式風(fēng)機(jī)的設(shè)計(jì)制造應(yīng)符合JB／T 4358的規(guī)定。
4.1.3 軸流式風(fēng)機(jī)的設(shè)計(jì)制造應(yīng)符合JB／T 4362的規(guī)定。
4.1.4 風(fēng)機(jī)葉輪(或葉片)的自振頻率應(yīng)避開葉輪的轉(zhuǎn)速頻率及其10倍以下倍頻和其他危險(xiǎn)頻率，如葉片通過頻率即轉(zhuǎn)速(采用轉(zhuǎn)速調(diào)節(jié)的風(fēng)機(jī)包括轉(zhuǎn)速調(diào)節(jié)范圍內(nèi)的所有轉(zhuǎn)速)與葉片數(shù)(包括轉(zhuǎn)子葉片和葉輪前后調(diào)節(jié)或?qū)蛉~片)的乘積、高幅值的氣流脈動(dòng)頻率等。
4.1.5 采用變速調(diào)節(jié)的風(fēng)機(jī)，應(yīng)進(jìn)行軸系扭轉(zhuǎn)振動(dòng)計(jì)算，防止軸系發(fā)生扭轉(zhuǎn)振動(dòng)。
4.1.6 風(fēng)機(jī)應(yīng)設(shè)有必要的自動(dòng)報(bào)警和保護(hù)裝置(如軸承溫度、斷油、振動(dòng)和軸流式風(fēng)機(jī)的失速喘振等)。
4.1.7 自大氣吸氣的風(fēng)機(jī)(如送風(fēng)機(jī)、一次風(fēng)機(jī))應(yīng)配備進(jìn)口消聲器，消聲器的設(shè)計(jì)和制造應(yīng)符合JB／T 6891的規(guī)定。
4.2 設(shè)計(jì)要求
4.2.1 熱一次風(fēng)機(jī)的設(shè)計(jì)進(jìn)口空氣溫度為250℃，允許最高進(jìn)口空氣溫度不超過400℃，空氣的含塵濃度不超過100mg／m3。其設(shè)計(jì)應(yīng)符合JB／T 8822的規(guī)定。
4.2.2 引風(fēng)機(jī)上游煙氣系統(tǒng)配備有低溫省煤器的系統(tǒng)，引風(fēng)機(jī)入口溫度在90℃左右，具有腐蝕性，在風(fēng)機(jī)的通流部分應(yīng)采取可靠的防腐措施。
4.2.3 排粉風(fēng)機(jī)(煤粉風(fēng)機(jī))設(shè)計(jì)要求輸送的介質(zhì)是含煤粉的空氣。其含煤粉量，對(duì)于鋼球磨煤機(jī)中間儲(chǔ)倉(cāng)式制粉系統(tǒng)的乏氣不大于80g／m3，對(duì)于負(fù)壓直吹式制粉系統(tǒng)為300g／m3～800g／m3。其設(shè)計(jì)進(jìn)口氣體溫度為70℃，允許最高進(jìn)口氣體溫度為150℃。機(jī)殼和葉輪應(yīng)根據(jù)煤的磨損特性(磨損指數(shù)的高低見DL／T 5145)采取防磨損措施，其葉輪的使用壽命不少于8000h。
4.2.4 煙氣再循環(huán)風(fēng)機(jī)設(shè)計(jì)要求輸送的介質(zhì)為含灰量不大于20g／m3、溫度不高于400℃的熱煙氣。其蝸殼和葉輪應(yīng)采取適當(dāng)?shù)姆滥p措施；軸承需設(shè)專門的隔熱和冷卻裝置，其使用壽命不得少于8000h。未配置調(diào)速裝置的煙氣再循環(huán)機(jī)應(yīng)設(shè)置盤車裝置。
4.2.5 密封風(fēng)機(jī)的設(shè)計(jì)應(yīng)采取消聲措施。對(duì)從大氣直接吸氣的密封風(fēng)機(jī)，應(yīng)配備進(jìn)口過濾器和進(jìn)、出口消聲器。
5 風(fēng)機(jī)的選型
5.1 選擇風(fēng)機(jī)應(yīng)提供的原始數(shù)據(jù)
選擇風(fēng)機(jī)應(yīng)提供的原始數(shù)據(jù)至少包括：
a) 當(dāng)?shù)卮髿鈼l件：
1) 大氣壓力；
2) 干、濕空氣溫度；
3) 空氣相對(duì)濕度。
b) 鍋爐熱力計(jì)算和空氣動(dòng)力計(jì)算結(jié)果。
c) 鍋爐各典型工況下的風(fēng)機(jī)參數(shù)：
1) 流量(風(fēng)量、煙氣量)；
2) 風(fēng)機(jī)進(jìn)口側(cè)系統(tǒng)總阻力(即風(fēng)機(jī)進(jìn)口全壓)和與之對(duì)應(yīng)的風(fēng)機(jī)進(jìn)口風(fēng)道截面動(dòng)壓；
3) 風(fēng)機(jī)出口側(cè)系統(tǒng)總阻力(即風(fēng)機(jī)出口全壓)；
4) 風(fēng)(煙)系統(tǒng)總阻力(即風(fēng)機(jī)壓力，以往稱風(fēng)機(jī)全壓)；
5) 介質(zhì)溫度；
6) 介質(zhì)標(biāo)準(zhǔn)密度(空氣介質(zhì)為當(dāng)?shù)貪窨諝獾臉?biāo)準(zhǔn)密度；煙氣介質(zhì)為風(fēng)機(jī)進(jìn)口濕煙氣的標(biāo)準(zhǔn)密度)。
注：各典型工況包括：
——選型工況(TB)；
——BMCR工況；
——BRL工況；
——THA工況；
——75％THA工況；
——50％THA工況；
——不投油最低穩(wěn)燃工況。
d) 機(jī)組在不同負(fù)荷下年運(yùn)行小時(shí)數(shù)。
5.2 風(fēng)機(jī)選型參數(shù)的確定
5.2.1 基本風(fēng)量按照以下要求確定：
a) 對(duì)于新建鍋爐的風(fēng)機(jī)，基本風(fēng)量按GB 50660的相關(guān)規(guī)定確定。
b) 對(duì)于改造已投運(yùn)的風(fēng)機(jī)，其基本風(fēng)量需由現(xiàn)場(chǎng)試驗(yàn)確定。試驗(yàn)工況不少于三個(gè)(在機(jī)組高、中、低三個(gè)負(fù)荷下進(jìn)行)，并將試驗(yàn)結(jié)果換算至鍋爐最大連續(xù)蒸發(fā)量(BMCR)工況下的流量。
5.2.2 基本風(fēng)壓按照以下要求確定：
a) 對(duì)于新建鍋爐的風(fēng)機(jī)，其基本風(fēng)壓按GB 50660的相關(guān)規(guī)定進(jìn)行計(jì)算，計(jì)算所得的風(fēng)機(jī)系統(tǒng)阻力宜參考同類型機(jī)組的實(shí)際運(yùn)行值確定是否需進(jìn)行調(diào)整。
b) 對(duì)于改造已投運(yùn)的風(fēng)機(jī)，其基本風(fēng)壓由現(xiàn)場(chǎng)試驗(yàn)確定(風(fēng)壓試驗(yàn)應(yīng)與流量試驗(yàn)同時(shí)進(jìn)行，并通過DCS對(duì)系統(tǒng)內(nèi)各主要設(shè)備及有關(guān)管道的阻力進(jìn)行采集)。必要時(shí)，進(jìn)行測(cè)量和／或通過SIS采集近一年內(nèi)機(jī)組滿負(fù)荷時(shí)風(fēng)機(jī)進(jìn)、出口壓力值予以核對(duì)。應(yīng)同時(shí)考慮風(fēng)機(jī)對(duì)應(yīng)系統(tǒng)(包括系統(tǒng)中的其他設(shè)備)的改造引起的阻力變化，并將換算至鍋爐最大連續(xù)蒸發(fā)量(BMCR)下的系統(tǒng)總阻力確定為風(fēng)機(jī)選型的基本風(fēng)壓。
5.2.3 風(fēng)量、風(fēng)壓裕量按照以下要求選取：
a) 對(duì)于新建鍋爐的風(fēng)機(jī)，流量與壓力的裕量宜根據(jù)GB 50660的相關(guān)規(guī)定選取。
b) 改造已投運(yùn)的風(fēng)機(jī)，風(fēng)機(jī)流量、壓力裕量，宜在考慮改造前試驗(yàn)時(shí)的氣候條件與當(dāng)?shù)叵摹⒍瑑杉静町悺㈠仩t設(shè)備及煙風(fēng)系統(tǒng)運(yùn)行狀況，以及機(jī)組負(fù)荷系數(shù)及煤質(zhì)變化范圍等因素的基礎(chǔ)上確定：也可參照GB 50660的規(guī)定選取。
5.3 風(fēng)機(jī)轉(zhuǎn)速、臺(tái)數(shù)及型式的選擇
5.3.1 風(fēng)機(jī)轉(zhuǎn)速的選擇，一般情況下，一次風(fēng)機(jī)宜選用4極電動(dòng)機(jī)(1490r／min)；送風(fēng)機(jī)宜選用4極或6極電動(dòng)機(jī)(1490r／min或990r／min)；引風(fēng)機(jī)和脫硫增壓風(fēng)機(jī)的轉(zhuǎn)速宜選用6極以下電動(dòng)機(jī)(即最高990r／min)，對(duì)于變轉(zhuǎn)速調(diào)節(jié)的引、增壓風(fēng)機(jī)合一的靜葉調(diào)節(jié)軸流式引風(fēng)機(jī)，根據(jù)參數(shù)需要可選取高于990r／min的轉(zhuǎn)速，但需滿足結(jié)構(gòu)強(qiáng)度及剛度可靠的要求。
5.3.2 風(fēng)機(jī)臺(tái)數(shù)的選擇按照以下要求進(jìn)行：
a) 對(duì)50MW及以上機(jī)組，鍋爐風(fēng)機(jī)臺(tái)數(shù)宜符合GB 50660的相關(guān)規(guī)定(送風(fēng)機(jī)、引風(fēng)機(jī)、冷一次風(fēng)機(jī)每爐宜各設(shè)置2臺(tái)：增壓風(fēng)機(jī)臺(tái)數(shù)宜與脫硫裝置臺(tái)數(shù)相同：排粉機(jī)臺(tái)數(shù)應(yīng)與磨煤機(jī)臺(tái)數(shù)相同；制粉系統(tǒng)密封風(fēng)機(jī)每爐設(shè)置2臺(tái)，一運(yùn)一備)。
b) 對(duì)25MW級(jí)機(jī)組配套的鍋爐應(yīng)裝設(shè)1臺(tái)送風(fēng)機(jī)和2臺(tái)引風(fēng)機(jī)，但燃油燃?xì)庳?fù)壓鍋爐應(yīng)裝設(shè)1臺(tái)送風(fēng)機(jī)和1臺(tái)引風(fēng)機(jī)。
c) 對(duì)12MW級(jí)及以下機(jī)組配套的鍋爐應(yīng)裝設(shè)1臺(tái)送風(fēng)機(jī)和1臺(tái)引風(fēng)機(jī)。
d) 對(duì)50MW～600MW級(jí)機(jī)組，經(jīng)技術(shù)經(jīng)濟(jì)論證和可靠性論證可行者，可采用每臺(tái)鍋爐僅設(shè)置1臺(tái)送風(fēng)機(jī)、1臺(tái)引風(fēng)機(jī)和1臺(tái)一次風(fēng)機(jī)。
e) 視布置條件和機(jī)組設(shè)計(jì)負(fù)荷率情況，經(jīng)技術(shù)經(jīng)濟(jì)論證可行時(shí)，引風(fēng)機(jī)也可設(shè)置3臺(tái)～4臺(tái)。
5.3.3 風(fēng)機(jī)型式的選擇按TB工況參數(shù)和選取的風(fēng)機(jī)轉(zhuǎn)速計(jì)算出所需風(fēng)機(jī)的比轉(zhuǎn)速，然后選取比轉(zhuǎn)速最接近的風(fēng)機(jī)型式。對(duì)于給定的參數(shù)，當(dāng)可以選擇幾種不同型式的風(fēng)機(jī)時(shí)，應(yīng)根據(jù)鍋爐機(jī)組的年負(fù)荷曲線、風(fēng)機(jī)耗電、調(diào)節(jié)效率、設(shè)備造價(jià)、維護(hù)費(fèi)用及其他因素進(jìn)行綜合技術(shù)經(jīng)濟(jì)比較來選擇。不同類型風(fēng)機(jī)比轉(zhuǎn)速參考范圍見表1。
表1 不同類型風(fēng)機(jī)比轉(zhuǎn)速參考范圍
風(fēng)機(jī)類型 比轉(zhuǎn)速
單吸離心式風(fēng)機(jī) 18～94
雙吸離心式風(fēng)機(jī) 25～120
靜葉調(diào)節(jié)子午加速軸流式風(fēng)機(jī) 90～120
單級(jí)靜葉調(diào)節(jié)標(biāo)準(zhǔn)軸流式風(fēng)機(jī)和動(dòng)葉調(diào)節(jié)軸流式風(fēng)機(jī) 100～200
雙級(jí)靜、動(dòng)葉調(diào)節(jié)軸流式風(fēng)機(jī) 59.5～119
5.4 風(fēng)機(jī)型號(hào)的選擇
5.4.1 確定風(fēng)機(jī)型號(hào)應(yīng)遵循的原則如下：
a) 風(fēng)機(jī)型式確定后，即可按相似設(shè)計(jì)方法確定風(fēng)機(jī)型號(hào)，并應(yīng)使系統(tǒng)阻力曲線完全落在所選風(fēng)機(jī)性能曲線的穩(wěn)定區(qū)域內(nèi)，且失速裕度足夠。
b) 對(duì)于離心式風(fēng)機(jī)，還應(yīng)避開氣流高脈動(dòng)區(qū)域。
c) 對(duì)于可選不同型式或型號(hào)的風(fēng)機(jī)時(shí)，在滿足安全運(yùn)行需要后，應(yīng)根據(jù)機(jī)組負(fù)荷、利用小時(shí)數(shù)、設(shè)備費(fèi)及年維護(hù)費(fèi)等技術(shù)經(jīng)濟(jì)指標(biāo)確定風(fēng)機(jī)的型號(hào)。
5.4.2 離心式風(fēng)機(jī)型號(hào)的選擇應(yīng)使選型工況點(diǎn)(即TB點(diǎn))盡可能接近調(diào)節(jié)裝置最大開度時(shí)的流量-壓力曲線，并且位于風(fēng)機(jī)最高效率的右側(cè)，其效率值不應(yīng)低于風(fēng)機(jī)最高效率的90％。
5.4.3 軸流式風(fēng)機(jī)型號(hào)的選擇應(yīng)在滿足風(fēng)機(jī)選型工況點(diǎn)(即TB點(diǎn))能安全可靠運(yùn)行的前提下，應(yīng)使發(fā)電機(jī)組在經(jīng)濟(jì)負(fù)荷下(一般為發(fā)電機(jī)組額定出力)運(yùn)行時(shí)，風(fēng)機(jī)處于最高效率區(qū)運(yùn)行。
5.4.4 軸流式風(fēng)機(jī)選型時(shí)應(yīng)確保有足夠的失速裕度，關(guān)于失速裕度(失速安全系數(shù))的定義與要求如下：
a) 失速裕度可用失速安全系數(shù)k來表示，k由各設(shè)計(jì)工況點(diǎn)和對(duì)應(yīng)開度下(動(dòng)葉調(diào)節(jié)為動(dòng)葉角度，靜葉調(diào)節(jié)為調(diào)節(jié)導(dǎo)葉角度)的失速工況點(diǎn)(或最大壓力點(diǎn))的流量、壓力，并按式(2)計(jì)算得出：
(2)
式中：
p、q——各設(shè)計(jì)工況點(diǎn)的壓力和流量：
pk、qk——各失速工況點(diǎn)的壓力和流量。
b) 在選型設(shè)計(jì)時(shí)，各設(shè)計(jì)工況點(diǎn)k值宜大于1.35，即k＞1.35。
5.5 風(fēng)機(jī)調(diào)節(jié)方式的選擇
5.5.1 對(duì)于動(dòng)葉調(diào)節(jié)軸流式風(fēng)機(jī)，當(dāng)機(jī)組設(shè)計(jì)負(fù)荷系數(shù)低于70％，且設(shè)計(jì)轉(zhuǎn)速在1000r／min以下時(shí)，動(dòng)葉調(diào)節(jié)軸流式風(fēng)機(jī)宜選用雙速電動(dòng)機(jī)變極數(shù)調(diào)節(jié)或選用變轉(zhuǎn)速裝置(變頻器、汽輪機(jī)驅(qū)動(dòng)或其他變速裝置)調(diào)節(jié)，在機(jī)組較低負(fù)荷運(yùn)行時(shí)切換或調(diào)節(jié)至低轉(zhuǎn)速運(yùn)行。特別注意：動(dòng)葉調(diào)節(jié)軸流式風(fēng)機(jī)在選用變速的調(diào)節(jié)方式時(shí)，應(yīng)取得制造廠對(duì)設(shè)備變速運(yùn)行安全可靠性的保證。
5.5.2 對(duì)于靜葉調(diào)節(jié)軸流式風(fēng)機(jī)，當(dāng)機(jī)組設(shè)計(jì)負(fù)荷系數(shù)低于80％以下時(shí)，靜葉調(diào)節(jié)軸流式風(fēng)機(jī)宜選用變轉(zhuǎn)速裝置(變頻器、汽輪機(jī)驅(qū)動(dòng)或其他變速裝置)調(diào)節(jié)。
5.5.3 對(duì)于離心式風(fēng)機(jī)，一般選擇入口導(dǎo)向器調(diào)節(jié)；為得到更佳的經(jīng)濟(jì)性，宜選用雙速電動(dòng)機(jī)變極數(shù)調(diào)節(jié)或變速裝置(變頻器、汽輪機(jī)驅(qū)動(dòng)或其他變速裝置)調(diào)節(jié)。
5.5.4 對(duì)于排粉風(fēng)機(jī)(一般為離心式)通常宜選擇入口節(jié)流門調(diào)節(jié)；也可選用入口調(diào)節(jié)門調(diào)節(jié)，但應(yīng)對(duì)入口門采取相應(yīng)的密封和防磨措施。
5.5.5 采用變轉(zhuǎn)速調(diào)節(jié)的風(fēng)機(jī)，選用何種變速調(diào)節(jié)裝置及其調(diào)節(jié)范圍，應(yīng)經(jīng)過詳細(xì)的技術(shù)經(jīng)濟(jì)比較來確定。
5.6 風(fēng)機(jī)選型的基本資料
制造廠應(yīng)提供的基本資料要求如下：
a) 風(fēng)機(jī)選型的必要資料，參見附錄A。
b) 對(duì)各制造廠所選風(fēng)機(jī)進(jìn)行評(píng)定時(shí)，通常需要供應(yīng)商提供的最少資料參見附錄B。
6 風(fēng)機(jī)的運(yùn)行
6.1 風(fēng)機(jī)的運(yùn)行區(qū)域
6.1.1 為避免高的氣流脈動(dòng)對(duì)風(fēng)機(jī)造成危害，離心式風(fēng)機(jī)不應(yīng)在可能引起喘振的不穩(wěn)定區(qū)域內(nèi)運(yùn)行，也不應(yīng)在氣流高脈動(dòng)區(qū)域(如有)內(nèi)運(yùn)行，同時(shí)還應(yīng)避免入口調(diào)節(jié)門開度在30％以下長(zhǎng)期運(yùn)行。
6.1.2 軸流式風(fēng)機(jī)應(yīng)避免所有可能的運(yùn)行工況在失速區(qū)域(不穩(wěn)定工況區(qū)域)內(nèi)運(yùn)行。
6.2 風(fēng)機(jī)的并聯(lián)運(yùn)行
6.2.1 兩臺(tái)風(fēng)機(jī)并聯(lián)運(yùn)行時(shí)系統(tǒng)工作點(diǎn)是由每臺(tái)風(fēng)機(jī)各自運(yùn)行點(diǎn)綜合而成。若一臺(tái)風(fēng)機(jī)停止運(yùn)行，則另一臺(tái)風(fēng)機(jī)運(yùn)行點(diǎn)將根據(jù)系統(tǒng)阻力特性的需要進(jìn)行匹配。
6.2.2 對(duì)于離心式前彎風(fēng)機(jī)，在停運(yùn)一臺(tái)風(fēng)機(jī)時(shí)需注意監(jiān)視風(fēng)機(jī)的電流，以防電動(dòng)機(jī)超載。
6.2.3 對(duì)于軸流式風(fēng)機(jī)，單臺(tái)風(fēng)機(jī)的最大出力取決于動(dòng)葉(或靜葉)的最大運(yùn)行角度和電動(dòng)機(jī)容量。當(dāng)要啟動(dòng)停用的風(fēng)機(jī)時(shí)，其隔離門宜關(guān)閉，葉片角度(動(dòng)葉調(diào)節(jié)為動(dòng)葉角度，靜葉調(diào)節(jié)為調(diào)節(jié)導(dǎo)葉角度)宜調(diào)至最小，當(dāng)風(fēng)機(jī)達(dá)到全速后，隔離門打開。在任何情況下，當(dāng)?shù)谝慌_(tái)風(fēng)機(jī)運(yùn)行時(shí)的壓力高于第二臺(tái)風(fēng)機(jī)失速界線的最低點(diǎn)壓力時(shí)，不應(yīng)啟動(dòng)第二臺(tái)風(fēng)機(jī)進(jìn)行并聯(lián)。如需并聯(lián)，則應(yīng)降低第一臺(tái)風(fēng)機(jī)的出力，使其運(yùn)行點(diǎn)的降低至第二臺(tái)失速界限壓力后再啟動(dòng)第二臺(tái)風(fēng)機(jī)進(jìn)行并聯(lián)。
6.2.4 停用的風(fēng)機(jī)再次啟動(dòng)時(shí)，該風(fēng)機(jī)的隔離門和入口調(diào)節(jié)門均宜關(guān)閉，以減少啟動(dòng)阻力矩和啟動(dòng)時(shí)間。如果由于上述風(fēng)門的泄漏而造成風(fēng)機(jī)在啟動(dòng)前反轉(zhuǎn)時(shí)，啟動(dòng)應(yīng)特別謹(jǐn)慎(大型離心式風(fēng)機(jī)特別是引風(fēng)機(jī)宜配備制動(dòng)或盤車裝置)，以防止啟動(dòng)時(shí)間過長(zhǎng)而損壞電動(dòng)機(jī)。通常，無調(diào)速和軟啟動(dòng)設(shè)備的風(fēng)機(jī)啟動(dòng)時(shí)間應(yīng)限制在25s以內(nèi)。
6.3 風(fēng)機(jī)運(yùn)行、維護(hù)及檢查
6.3.1 風(fēng)機(jī)的運(yùn)行參數(shù)如風(fēng)量、風(fēng)壓、電流、軸承振動(dòng)、軸承溫度及風(fēng)機(jī)進(jìn)口和(或)出口的介質(zhì)溫度等，應(yīng)在控制室內(nèi)有儀表顯示。對(duì)軸流式風(fēng)機(jī)宜做到在線監(jiān)視畫面上顯示風(fēng)機(jī)運(yùn)行工況點(diǎn)位于性能曲線上的位置，以便運(yùn)行人員了解風(fēng)機(jī)的實(shí)際運(yùn)行情況，避免風(fēng)機(jī)在不希望的工況下運(yùn)行。大型風(fēng)機(jī)的軸承振動(dòng)和溫度還應(yīng)設(shè)有報(bào)警信號(hào)。所有監(jiān)視儀表都應(yīng)定期進(jìn)行校準(zhǔn)。
6.3.2 定期對(duì)風(fēng)機(jī)進(jìn)行維護(hù)檢查，及時(shí)排除運(yùn)行中出現(xiàn)的故障和異常。主要檢查項(xiàng)目有軸承、磨損和腐蝕程度、積灰情況、焊縫和鉚接質(zhì)量、動(dòng)葉調(diào)節(jié)軸流式風(fēng)機(jī)的動(dòng)葉螺栓連接、油系統(tǒng)和調(diào)節(jié)機(jī)構(gòu)，
包括行程范圍、靈活性、各調(diào)節(jié)葉片動(dòng)作的一致性，以及實(shí)際開度與指示儀表的一致性等。
6.3.3 風(fēng)機(jī)正式投運(yùn)前，各電廠應(yīng)根據(jù)制造廠提供的資料和管網(wǎng)系統(tǒng)的具體條件，以及安裝完畢后的一系列調(diào)整試驗(yàn)的結(jié)果，編制出具體可行的風(fēng)機(jī)運(yùn)行操作規(guī)程，作為運(yùn)行人員操作、檢查、維護(hù)的依據(jù)。
