建筑環(huán)境與能源應(yīng)用工程專業(yè)英語1ppt課件

1、Unit FifteenCommissioning of Variable Air Volume SystemsWhat is Commissioning (Cx) ? Definition: “A quality-focused process for enhancing the delivery of a project. The process focuses on verifying and documenting that the facility and all of its systems and assemblies are planned, designed, install

2、ed, tested, operated, and maintained to meet the Owners Project Requirements.” ASHRAE Guideline 0-2019, The Commissioning Process Commissioning is often performed by an independent third-party engineering company. Operates as an owners representative to insure the installed systems meet the owners r

3、equirements and the plans and specifications Usually hired by the owner, sometimes by the architect, or general contractor. Commissioning PersonAll participants in the construction project have a commissioning responsibility. Participants include the commissioning authority, owner, design profession

4、als, construction manager, general contractor, subcontractors, operation and maintenance manager, suppliers, and equipment manufacturers.Benefits of Commissioning Reduced change orders Less warranty and callbacks for contractor Smoother turnover to maintenance Improved equipment reliability Reduced

5、IEQ problems Reduced occupant complaints Improved productivity Correct system operation and installation Facility meets Owners expectation and operational needs Reduced utility consumption and operational costsCommissioning Objectives Ensure the facility meets the owners performance requirements Pro

6、vide a safe and healthy environment Provide optimum energy performance Provide a facility that can be efficiently operated and maintained Provide complete orientation and training to facility staff and occupants Provide improved documentation of system characteristicsCommissioning - What did we use

7、to do and why do we need it? CX of mechanical and electrical systems was done by the installing contractors No standardization, or clear approach Most of the real CX occurred during the warranty period as warranty calls Buildings operated less efficiently First year of occupancy was frustrating for

8、the owner Contractors spent more money during the warranty periods Contractors can be rushed without enough time to double-check their work Design Engineers do not have enough budget to oversee the construction in detail Owners have had bad experiences with prolonged project closeout, and see CX as

9、a solution Hold contractors accountable for the specificationsCommissioning Scope Mechanical Systems All HVAC equipment Building automation system and hardwired controls Electrical Systems Switchgear, major disconnects, backup generators and UPS (Uninterrupted Power Supply) Fire Safety Systems Secur

10、ity Systems Kitchen equipment Irrigation system Laboratory Fume hoods, gas controlCommissioning and Construction PhasesPrepare,Design Intent, CX Plan,and SpecificationsReviewSubmittals,Prepare Checklists and Testing PlansVerifyComponents,Witness Start-Upand ComponentTestingPerformFunctionalTesting,

11、ResolveDeficiencies,ReviewO&MPrepareCX Report,Staff Training,DefineSeasonalTestingPlanningDesignConstructionOccupancyAcceptanceOther Types of Commissioning Retro-commissioning Performed to existing buildings that have not previously been commissioned, after they have been occupied Usually instig

12、ated as a result of high energy bills or poor occupant comfort Recommissioning Performed 5 to 10 years after a building was previously commissioned Sometime used as a form of deferred maintenanceVariable Air Volume (VAV)use of varying airflow to control the condition of air, in contrast to the use o

13、f constant flow (often) with varying temperature.VAV system controls temperature in a space by varying the quantity of supply air rather than varying the supply air temperature. A VAV terminal unit at the zone varies the quantity of supply air to the space. The supply air temperature is held relativ

14、ely constant: while supply air temperature can be moderately reset depending on the season, it must always be low enough to meet the cooling load in the most demanding zone, and to maintain appropriate humidity.Why use VAV?Provides multiple zones of comfortLife cycle cost will be less than other HVA

15、C Systems trying to accomplish similar comfort levelsLoad diversitySmaller equipment ( lower AC unit first cost compared to Constant Volume)Less supply air ( less energy consumption)Able to adapt to changes in building useWhy Not ?Higher first cost than comparable single zone Controls, equipment, co

16、mmissioningIncreased maintenance costMore pieces to look afterConstant volume - variable temperature system have been dominating the HVAC applications in the past for obvious reasons. The implementation of variable volume control has been done with dampers or other mechanical control methods.The adv

17、antages of variable air volume system implemented with variable speed control are: Fast control to keep the comfort zone limits Low consumption of electrical energy Lower consumption of heating and cooling energy than in constant air volume systems Simpler to keep noise level down 1. Introduction2.

18、Commissioning method statement3. System components 4. Preliminary checks5. Commissioning sequence 6. Setting to work 7. Terminal units 8. Secondary air distribution9. Return air spigots 10. System diversity 11. Fan design performance check 12. System performance checks Frequently used words and phra

19、ses:Variable air volume (VAV) system 變風(fēng)量系統(tǒng)變風(fēng)量系統(tǒng)commissioning 試運(yùn)行試運(yùn)行 調(diào)試調(diào)試 air volume flow rate 空氣體積流量空氣體積流量terminal unit 終端設(shè)備終端設(shè)備 flexible duct 柔性風(fēng)管柔性風(fēng)管Pitot tube 畢托管畢托管 thermal anemometer 熱線風(fēng)速儀熱線風(fēng)速儀supply fan 送風(fēng)風(fēng)機(jī)送風(fēng)風(fēng)機(jī) extract fan 排風(fēng)機(jī)排風(fēng)機(jī)over-pressurization 壓力過高壓力過高 spigot 套套管、栓、龍頭管、栓、龍頭1. Variable ai

20、r volume (VAV) systems are dynamic air distribution systems and, as their name implies, the air volume flow rate is varied according to various parameters to achieve the required design conditions.2. The fact that VAV systems are designed to vary system performance imposes a number of specific tasks

21、 on the commissioning specialist, which must be carried out in order to achieve satisfactory overall performance.3. Proprietary units may employ a variety of means of regulating air volume flow rate including motorized dampers, inflating bellows, restricting flexible duct sections or a combination o

22、f such devices.Variable air volume (VAV) systems: 變風(fēng)量系統(tǒng)變風(fēng)量系統(tǒng) dynamic: 動態(tài)的動態(tài)的air volume flow rate: 空氣體積流率空氣體積流率 design conditions: 設(shè)計(jì)條件設(shè)計(jì)條件impose: 施加施加 帶來帶來 commissioning specialist: 調(diào)試人員調(diào)試人員proprietary: 私人擁有的私人擁有的 inflating bellows: 靜壓箱靜壓箱 常用常用plenum chamberflexible duct section: 柔性風(fēng)管部件柔性風(fēng)管部件plenum

23、chamber靜壓箱靜壓箱acoustic plenum chamber 消聲靜壓箱消聲靜壓箱靜壓箱是送風(fēng)系統(tǒng)減少動壓、增加靜壓、穩(wěn)定氣流和減少氣流靜壓箱是送風(fēng)系統(tǒng)減少動壓、增加靜壓、穩(wěn)定氣流和減少氣流振動的一種必要的配件，它可使送風(fēng)效果更加理想。振動的一種必要的配件，它可使送風(fēng)效果更加理想。 靜壓箱的作用靜壓箱的作用 可以把部分動壓變?yōu)殪o壓使風(fēng)吹得更遠(yuǎn)；可以把部分動壓變?yōu)殪o壓使風(fēng)吹得更遠(yuǎn)； 可以降低噪音可以降低噪音 風(fēng)量均勻分配風(fēng)量均勻分配 靜壓箱可用來減少噪聲，又可獲得均勻的靜壓出風(fēng)，減少靜壓箱可用來減少噪聲，又可獲得均勻的靜壓出風(fēng)，減少動壓損失。而且還有萬能接頭的作用。把靜壓箱很好地應(yīng)動

24、壓損失。而且還有萬能接頭的作用。把靜壓箱很好地應(yīng)用到通風(fēng)系統(tǒng)中，可提高通風(fēng)系統(tǒng)的綜合性能。用到通風(fēng)系統(tǒng)中，可提高通風(fēng)系統(tǒng)的綜合性能。 4. Control sensors may measure air flow by means of pressure differential, Pitot tube, flow grid or thermal anemometer using spot or averaging sensors.5. The guidance is not system-specific, because the detailed tasks associated with

25、 one system type may not be the same for another type.6. VAV system technology offers such a wide range of design options and proprietary components that the resulting installations are likely to require different commissioning techniques.pitot tube: 畢托管畢托管 flow grid: 流動網(wǎng)格流動網(wǎng)格thermal anemometer: 熱線風(fēng)

26、速儀熱線風(fēng)速儀option: 選擇選擇 選項(xiàng)選項(xiàng)system-specific: 根據(jù)系統(tǒng)而特殊或不同的根據(jù)系統(tǒng)而特殊或不同的7. To ensure that the appropriate commissioning procedures are employed, the commissioning specialist should carefully review the recommendations of the equipment suppliers.8. VAV systems typically comprise the following components, some

27、 of which may require specialist commissioning by the manufacturer in addition to general commissioning as part of a complete air distribution system9. A particular check should be made to ensure that distribution ductwork internals are clean throughout. If there is any doubt regarding the state of

28、system cleanliness, the commissioning specialist should formally draw attention to this.review: 查閱查閱 復(fù)習(xí)復(fù)習(xí) equipment suppliers: 設(shè)備提供商設(shè)備提供商how to translate?internal: 內(nèi)部內(nèi)部 draw attention to: 對對注意注意10. With the supply and extract fans operating simultaneously, the running speed should be increased gradu

29、ally. Motor running current checks should be made at various increments, and the results recorded for each fan, to assess performance and prevent overloading of the motor.11. The fans should then be stopped and made safe so that the cause of the static pressure irregularity can be investigated and r

30、ectified by the appropriate personnel before proceeding further.12. during the commissioning of the individual VAV terminals, it may be necessary to further fine-tune the fan speed to compensate for any system pressure variations.current: 電流電流 increment: 增量增量 overloading: 過載過載irregularity: 無規(guī)律無規(guī)律(的變

31、化的變化) rectify: 修正修正 調(diào)整調(diào)整personnel: 人員人員 proceed: 繼續(xù)進(jìn)行繼續(xù)進(jìn)行terminal: 終端終端 終點(diǎn)終點(diǎn) terminal station fine-tune: 微調(diào)微調(diào)13. All procedures and techniques to be applied in checking terminal unit volume flow rates should be in accordance with the manufacturers instructions and should be incorporated into the com

32、missioning method statement.14. Verification of these arrangements is necessary, and the number of VAV terminal units to be checked should be defined within the project commissioning specification.15. at the outset of the VAV terminal checks, the commissioning specialist should select a number of un

33、its with inlet duct configurations suitable for in-duct flow measurements to be taken.instruction: 指示指示 說明說明 instruction book specificationincorporate: 合并合并 結(jié)合結(jié)合 incorporated: 組成公司的組成公司的 Inc. DELL Inc.statement: 說明說明 陳說陳說verification: 確認(rèn)確認(rèn) 查證查證 define: 詳細(xì)說明詳細(xì)說明 outset: 開場開場 inlet duct configuration:

34、 風(fēng)管入口結(jié)構(gòu)風(fēng)管入口結(jié)構(gòu)in-duct flow: 風(fēng)管入口流動風(fēng)管入口流動16. Volume flow rate checks by pitot-static duct traverse should be conducted on these terminals to validate the method of flow rate measurement adopted within the commissioning method statement,17. With such an arrangement, the commissioning specialist must ba

35、lance proportionally each of the secondary terminals by the methods detailed in section A3.2 so that they discharge the specified proportion of the volume of air delivered by the VAV terminal, within the specified (or appropriate) tolerances.18. For all the above arrangements, regulation of the retu

36、rn air inlets must be carried out to achieve a proportional balance within the specified tolerance limits.pitot-static duct traverse: 風(fēng)管橫截面布置畢托管風(fēng)管橫截面布置畢托管conduct: 進(jìn)展進(jìn)展carry out: 執(zhí)行執(zhí)行secondary terminal: 二次終端設(shè)備二次終端設(shè)備 tolerance: 公差公差 允許的誤差允許的誤差specified: 指定的指定的19. It may be necessary to impose a reduce

37、d air flow condition on a number of terminals to achieve the required design diversity.20. Where necessary, guidance should be obtained from the unit supplier or manufacturer and close liaison with the designer is recommended to take account of any particular arrangements that may be required.21. Wi

38、th the required design system diversity applied, total flow rates should be measured and recorded by pitot traverse.diversity: 差別差別 多樣性多樣性How to translate?guidance: 指導(dǎo)指導(dǎo) liaison: 聯(lián)絡(luò)聯(lián)絡(luò) 聯(lián)絡(luò)聯(lián)絡(luò)22. In conjunction with this, the static pressure at the least favored unit should be monitored and the system operating pressure set to its optimum point, i.e. the lowest system