ASHRAE HVAC APPLICATIONS IP CH 27-2015 POWER PLANTS.pdf

1、27.1CHAPTER 27POWER PLANTSGeneral Design Criteria 27.1Ventilation Approach 27.4Applications . 27.4Steam Generator Buildings: Industrial and Power Facilities 27.5Turbine Generator Building. 27.7Combustion Turbine Areas. 27.9Main Control Center 27.9Substation and Switchyard Control Structures. 27.9Tur

2、bine Lubricating Oil Storage 27.10Oil Storage and Pump Buildings 27.10Coal Crusher and Coal Transportation System Buildings. 27.10Heating/Cooling Systems . 27.11Energy Recovery. 27.12Safety Considerations. 27.12HIS chapter discusses HVAC systems for industrial facilitiesTfor the production of proces

3、s heat and power and for electricalgenerating stations and transmission facilities. Not every type ofpower plant is specifically covered, but the process areas addressednormally correspond to similar process areas in any plant. For exam-ple, wood-fired boilers are not specifically discussed, but the

4、requirements for coal-fired boilers generally apply. Aspects ofHVAC system design unique to nuclear power plants are covered inChapter 28.Special Warning: Certain industrial spaces may contain flam-mable, combustible, and/or toxic concentrations of vapors or dustsunder either normal or abnormal cond

5、itions. In spaces such as these,there are life-safety issues that this chapter may not completelyaddress. Special precautions must be taken in accordance withrequirements of recognized authorities such as the National Fire Pro-tection Association (NFPA), the Occupational Safety and HealthAdministrat

6、ion (OSHA), the American National Standards Institute(ANSI), the facilitys insurance carriers, and authorities having juris-diction (AHJs). In all situations, engineers, designers, and installerswho encounter conflicting codes and standards must defer to thecode or standard that best addresses and s

7、afeguards life safety.1. GENERAL DESIGN CRITERIASpace-conditioning systems in power plant buildings aredesigned to maintain an environment for reliable operation of powergeneration systems and equipment and for the convenience andsafety of plant personnel. A balance is achieved between the cost ofth

8、e process systems designed to operate in a specified environmentand the cost of providing HVAC to modify or condition the environ-ment.Environmental criteria for personnel safety and comfort are gov-erned by several sources. The U.S. Occupational Safety and HealthAdministration (OSHA) defines noise,

9、 thermal environment, and aircontaminant exposure limits. Chapters 14 and 31 of this volume andIndustrial Ventilation by the American Conference of GovernmentalIndustrial Hygienists (ACGIH 2013) also provide guidance forsafety in work spaces, primarily in the areas of industrial ventilationand worke

10、r-related heat stress. Worker comfort is somewhat subjec-tive and more difficult to quantify. The plant owner or operator ordi-narily establishes the balance between cost and worker comfort.Exhaust vents are subject to regulation of the plants air qualitypermit and local air pollution control boards

11、 requirements. For thisreason, all exhaust vent locations should be properly identified andclassified, and coordinated with the plants environmental compli-ance permits. Treatment of exhaust streams is discussed in Chapter30 of the 2012 ASHRAE HandbookHVAC Systems and Equip-ment.Criteria should be c

12、learly defined at the start of design, becausethey document an understanding between the process designer andthe HVAC system engineer that is fundamental to achieving the envi-ronment required for the various process areas. Typical criteria for acoal-fired power plant are outlined in Table 1. Review

13、 criteria forcompliance with local codes, the plant operators experience andpreferences, and the facilitys overall financial objectives. Addi-tional discussion of criteria may be found in the sections on specificareas.Temperature and HumiditySelection of outdoor design temperatures is based on the o

14、perat-ing expectations of the plant. If the power production facility is crit-ical and must operate during severe conditions, then the effect oflocal extreme high and low temperatures on the systems should beevaluated. Electrical power consumption is usually highest underextreme outdoor conditions,

15、so critical areas of the plant should bedesigned to operate when needed the most. Other noncritical-areatemperature ranges, indicated in Table 1, may be more appropriatelyless stringent. A starting point for establishing design weather con-ditions for extreme conditions (typically defined on a 5, 10

16、, or 20year recurrence interval) and design (99.6% and 0.4% conditions)can be found in Chapter 14 of the 2013 ASHRAE HandbookFun-damentals and on the CD accompanying that volume.Indoor temperatures should match the specified operating temper-atures of the equipment. Electrical equipment, such as swi

17、tchgear,motor control centers, and motors, typically determines the designtemperature limits in the plant; common temperature ratings are 104or 122F. Other areas such as elevator machine rooms may includeelectronic equipment with temperature restrictions.In plant areas where compressed-gas container

18、s are stored, thedesign temperature is according to the gas supplier. Typically, theminimum temperature should be high enough that the gas volumecan be effectively released from the containers. If the gas is hazard-ous (e.g., chlorine), the minimum temperature does not apply dur-ing personnel occupa

19、ncy periods, when high dilution ventilationrates are needed.Practical ventilation rates for fuel-fired power plants provideindoor conditions 10 to 20F above the outdoor ambient. Therefore,ventilation design criteria establish a temperature rise above thedesign outdoor temperature to produce an expec

20、ted indoor temper-ature that matches the electrical equipment ratings. For example, anoutdoor extreme design temperature of 112F with a ventilation sys-tem designed for a 10F rise would meet the requirements of 122F-rated plant equipment. Because excursions above selected designoutdoor air temperatu

21、re are often brief (e.g., 2 to 3 h), the effect onroom temperature is minimal. In addition, the electrical equipmentThe preparation of this chapter is assigned to TC 9.2, Industrial Air Condi-tioning.27.2 2015 ASHRAE HandbookHVAC ApplicationsTable 1 Design Criteria for Fuel-Fired Power PlantBuilding

22、/AreaDesign Outdoor Cooling/ HeatingDry-BulbaIndoor Temperature, FRelative Humidity,%RoomVentilationRate, ach*FiltrationEfficiency,%Pressur-ization RedundancybNoiseCriterionMaximum MinimumSteam Turbine AreaSuboperating level 0.4%/99.6% Design outdoor + 10 45 None 30 None None Multiplicity Background

23、Above operating floor 0.4%/99.6% Design outdoor + 10 45 None 10 None None Multiplicity BackgroundCombustion Turbine Area 0.4%/99.6% Design outdoor + 18 45 None 20 None None Multiplicity BackgroundSteam Generator AreaBelow burner elevation 0.4%/99.6% Design outdoor + 10 45 None 30 None None Multiplic

24、ity BackgroundAbove operating floor 0.4%/99.6% Design outdoor + 10 45 None 15 None None Multiplicity BackgroundOther Non-Air-Conditioned AreasShops1%/99% Design outdoor + 10 65 None 15 None None None 85 dBAAir-Conditioned AreasdControl rooms and control equipment rooms containing instruments and ele

25、ctronicsExtreme 75 2 72 2 30 to 65 ASHRAEStd. 62.185 to 90(see text)Positive 100% NC-40c(see text)Offices 1%/99% 78 70 30 to 65 ASHRAEStd. 62.1ASHRAEStd. 62.1Positive None See textLaboratories 1%/99% 78 70 30 to 65 ASHRAEStd. 62.1High Positive None See textLocker rooms and toilets 1%/99% 78 70 None

26、ASHRAEStd. 62.1ASHRAEStd. 62.1Negative None See textShops (air-conditioned) 1%/99% 78 65 None ASHRAEStd. 62.1None None None 85 dBAMechanical EquipmentPumps, large power 0.4%/99.6% Design outdoor + 10 45 None 30 None None Multiplicity BackgroundValve stations, miscellaneous0.4%/99.6% Design outdoor +

27、 10 45 None 15 None None None 85 dBAElevator machine rooms 0.4%/99.6% 90 45 None None Low Positive None 85 dBAFire pump area 0.4%/99.6% NFPA NFPAStd. 20None NFPAStd. 20None None None 85 dBAStd. 20Diesel generator area 0.4%/99.6% Design outdoor + 10 45 None 30 None None None BackgroundElectrical Equi

28、pmentdEnclosed transformer equipment areas0.4%/99.6% Design outdoor + 10 45 None 60 Low Positive 100% 85 dBACritical equipment Extreme(see text)Design outdoor + 10 45 None 30 None Positive 100% 85 dBAMiscellaneous electricalequipment0.4%/99.6% Design outdoor + 10 45 None 20 None None Multiplicity 85

29、 dBAWater TreatmentChlorine equipment roomsWhen temporarily occupied0.4%/99.6% Design outdoor + 10 None None 60 None Negative None 85 dBAWhen unoccupied 0.4%/99.6% Design outdoor + 10 60 None 15 None Negative None 85 dBAChemical treatment 0.4%/99.6% Design outdoor + 10 60 None 10 None None None 85 d

30、BABattery Roomse0.4%/99.6% 77e77eNone As requiredfor hydrogendilutionNone Negativeor neutralMultiplicity 85 dBASubstations 0.4%/99.6% 75 to 80f70 None IEEE Std. C2; ASHRAE Std.62.130 to 65%gPositive 100% NC-55h*Listed numbers are for estimating purposes only. When heat gain data are available, use E

31、quation(1) to calculate required ventilation rate.aSee Chapter 14 of the 2013 ASHRAE HandbookFundamentals for design dry-bulb temperaturedata corresponding to given annual cumulative frequency of occurrence and specific geographiclocation of plant.bMultiplicity indicates that the HVAC system should

32、have multiple units.cSee Figure 7 in Chapter 8 of the 2013 ASHRAE HandbookFundamentals for noise criterion curves.dSee ASHRAE research project RP-1104 (White 2003) and RP-1395(White and Piesciorovsky 2010) for heat release values.eSee ASHRAE Guideline 21-2012 and section on Battery Rooms in thischap

33、ter.fSubstation temperature maintained for telecom equipment.gEquivalent to rough-in MERV 6 prefilter and MERV 12 secondary filter.hLower criteria should be considered for occupied substations.Power Plants 27.3temperature ratings are associated with design life, not sudden fail-ures. Carefully evalu

34、ate extreme temperatures for their duration anddiscuss them with the electrical system designer before adopting thedesign. In hot climates where outdoor temperatures may causeindoor temperatures to exceed electrical equipment ratings forextended periods, evaporative cooling or air conditioning of el

35、ectri-cal equipment areas may be required to hold temperatures below theequipment design values. When high area temperatures are possi-ble, the environment for plant maintenance workers should also beconsidered. Velocity (spot) cooling may be necessary in some areasto support work activities.Low tem

36、peratures may affect plant reliability because of thepotential for freezing. Selection of the low design temperatureshould be balanced by selection of the heating design margin. Ifthe record low temperature is used in the design, indoor designtemperatures of 35 to 40F may be used. In the heating sys

37、temdesign, credit is generally not taken for heat generated from operat-ing equipment.The selection of outdoor design humidity levels affects the selec-tion of cooling towers and evaporative cooling processes and the siz-ing of air-conditioning coils for outdoor air loads. When values fromChapter 14

38、 of the 2013 ASHRAE HandbookFundamentals are usedfor design, the mean coincident wet bulb is appropriate. If extremedry-bulb temperatures are selected for the design basis, the use ofextreme wet bulbs is too restrictive because the extremes are not coin-cident. It is prudent to use the wet bulb asso

39、ciated with the 1% drybulb when extreme dry-bulb temperatures are used for the design.Indoor design humidity is not a factor in ventilated areas unlessthe plant is in a harsh, corrosive environment. In this case, lowerhumidity reduces the potential for corrosion. In air-conditionedareas for personne

40、l or electronic equipment, ASHRAE Standard62.1, Instrumentation, Systems, and Automation Society (ISA)Standard 71.04, and manufacturers recommendations dictate thehumidity criteria.Ventilation RatesVentilation within plant structures provides heat removal anddilution of potentially hazardous gases.

41、Ventilation rates for heatremoval are calculated during HVAC system design to meet summerindoor design temperatures.The numbers in Table 1 for air change rates are for estimatingapproximate ventilation needs. Actual heat emission rates should beobtained from equipment manufacturers, White and Piesci

42、orovsky(2010), or from the engineers experience. American Boiler Manu-facturers Association (ABMA) heat loss curves (Stultz and Kitto2005) can be used to approximate heat loads from boiler casings ifbetter information is not available.The ventilation rate for room heat removal isQ = (1)whereQ = vent

43、ilation rate, cfmq = room heat, Btu/htr= suggested room temperature from Table 1, Fto= outdoor air temperature, F = air density, lbm/ft3cp= specific heat of air = 0.24 Btu/lbmFHazardous gases are mostly handled by the process systemdesign functions. Natural gas and other combustible fuel gases areco

44、ntrolled by ignition safeties and may contain odorants for detec-tion. Hydrogen and other gases used for generator and bus coolingare monitored for leakage by pressure loss or makeup rates. Escapedgases are diluted by outdoor air infiltration. For a building with verytight construction (i.e., very l

45、ittle natural infiltration), perform ananalysis to verify that dilution rates are acceptable.Flue gas is confined to the boiler and flue gas ductwork and gen-erally poses no hazard. In some types of boilers and associated gasducts, however, flue gas is at a higher pressure than the surroundingsand c

46、an leak into occupied areas. Also, special-treatment gases suchas ammonia or sulfur compounds encountered in flue gas condition-ing systems can leak into the boiler building, depending on the loca-tion of the treatment device in the flue gas stream. In these cases, gasdetection monitors should be us

47、ed.Ventilation for areas with hazardous gases (e.g., chlorine) shouldbe designed by specific gas industry standards such as The ChlorineManual (CI 1997) or ACGIH (2013).Infiltration and ExfiltrationInfiltration of outdoor air into boiler and power-generation struc-tures or exfiltration of room air f

48、rom these buildings is driven bythermal buoyancy of heated air. Both infiltration and exfiltration arebeneficial; infiltration air dilutes fugitive fumes, whereas exfiltra-tion air carries out excess heat during hot weather. However, infil-tration adds to the cold-weather load on the heating system.

49、Filtration and Space CleanlinessFiltration of ventilation air for process areas is usually notneeded because some process areas are dirtier than the outdoor sur-roundings, and the process equipment is designed to operate in adusty environment. However, the plant may be located in an areawith sources of outdoor particulate contaminants that need to bemanaged to protect the process equipment. Power plants in dusty orsandy areas, or where there are seasonal nuisances such as airborneplant matter, may require filtration of ventilation air. Plants at indus-trial sit