1、Air Heaters Supplement to Performance Test Code for Steam Generating Units, PTC 4.1 ASME PTC*4-3 bA 0757b.70 0054085 3 m PERFORMANCE Air Heaters Supplement to Performance Test Code TEST for Steam Generating Units, PTC 4.1 1 I CODES Library of Congress Catalog No. 68-21272 Copyright, 1968, by The Ame
2、rican Society of Mechanical Engineers Printed in the United States of America FOREWORD Performance Test Code Committee No. 4 on Stationary Steam-Generating Units was reorganized in May, 1958 to rewrite and bring up to date the 1946 edition of the Test Code for Stationary Steam-Generating Units. Duri
3、ng the formulation of the new Test Code, PTC 4.1-1964, the technical committee brought to the attention of the Performance Test Codes Committee that for the Air Heater, an auxiliary heat absorption equipment common to all large sttam generating units, there existed no power test code. PTC Com- mitte
4、e No, 4 recommended the development of such a Test Code as part of its assignment. The Performance Test Codes Committee instructed FTC Committee No. 4 to prepare such a Test Code as a Supplement to be known as PTC 4.3 on Air Heaters. This Test Code was developed and its format follows closely that o
5、f PTC 4.1, the Test Code for Steam Generating Units. This Test Code was approved by the Performance Test Codes Committee on June 9, 1966. Final publica- tion was delayed, however, until a number of suggestions made by the standing Committee were con- sidered and satisfactorily resolved. It was appro
6、ved and adopted by the Council as a standard practice of the Society by action of the Policy Board, Codes and Standards on November 8, 1967. January, 1968 ASME PTC*4-3 68 81 0757b70 0054088 7 m PERSONNEL OF PERFORMANCE TEST CODE COMMITTEE NO. 4 ON STATIONARY STEAM-GENERATING UNITS John M. Driscoll,
7、Chairman John V. Cleary, Jr., Secretary James U. Baley, General Superintendent, Electric Operations, Baltimore Gas and Electric Company, Gas and Electric Building, Baltimore, Maryland, 21203 Charles D. Birget, formerly Chief Mechanical Engineer, Commonwealth Associates, Inc., 209 E. Washington Avenu
8、e, Jackson, hlichigan, 49201 John A. Bostic, General Supervising Engineer, Civil and Mechanical Engineering Department, The Cleveland Electric Illuminating Company, Box 5000, Cleveland, Ohio, 44101 Hugh J. Byrne, Steam-Power Engineer, Central Engineering Office, Crown Zellerbach Corporation, 6363 Ai
9、rport Way, Seattle, Washington, 98108 John v. Cleary, Jr., Chief Cost Engineer, Cost Control Engineering Bureau, Consolidated Edison Company of New York? InC., 4 Irving Place, New York, New York, 10003 Leonard Cohen, Head, Operation Management Department, Naval Ship Engineering Center, Philadelphia
10、Division, U.S. Naval Base, Philadelphia, Pennsylvania, 19112 John M. Driscoll, Chief Mechanical Engineer, Consolidated Edison Company of Nelv York, Inc, 4 Irving Place, New York, New York, 10003 John H. Fernandes, Senior Project Engineer, Product Diversification, Combustion Engineering, Inc., Prospe
11、ct Hill Road, Windsor, Connecticut, 06095 William 2. Harper, Assistant Superintendent, Utilities Division, Kodak Park Works, Eastman Kodak Company, Rochester, New York, 14604 Edward C. Kistner, Engineer in Charge of Power Plant Section, Mechanical Engineering Division, Philadelphia Electric Company,
12、 9th and Sansom Streets, Philadelphia, Pennsylvania, 19105 Frank C. Lisevick, Mechanical Engineer, Stone Where A = Per cent = Air heater leakage as given in Par. 7.03 cP(l) = m = The mean specific heat between temperatures and G15 cG() = - = The mean specific heat between temperatures tCl5 and tG15
13、Btu Btu lb - F Where tc15 = F = Measured gas temperature leaving air heater. t8 = F = Measured air temperature entering air heater. (lFor the determination of the mean specific heats use PTC 4.1, Fig. 3 for air and Fig. 7 for gas to calculate the weighted average specific heat for wet air and wet ga
14、s. 21 ASME PERFORMANCE TEST CODES lb wet gas leaving entering air heater vG15914 = lb A.F. fuel = wG15, 14 + WmG (2 ) vG15314 = lb A.F. fuel lb moisture lb A.F. fuel 7,0s lb dry gas = Dry gas flow leaving/entering the air heater as given in Par. 7.04 RmG = = Total moisture in flue gas entering the a
15、ir heater as given in Par. 7.03.1 While not a part of this Code, an interesting empirical approximation of percentage of leakage may be obtained by the use of the per cent voIume of the CO2 in the gas entering and leaving the heater. The approximation does not account for the moisture in the flue ga
16、s. Thus: % LEAKAGE = % CO;! gas entering heater - % COZ gas leaving heater % CO2 gas leaving heater x 90 Experience has shown that the use of this factor, 90, will result in percentage leakage figures that are very close (plus or minus one percentage point) to leakage determined on a weight basis. 7
17、.04 lb dry gas lb A.F. fuel = = Pounds of dry gas per pound of “as fired” fuel. 7.04.1 4.01 CO, + 32.00 O2 + 28.01 CO -t 28.02 N2 12.01 WG14,15 = 12.01 (CO, + CO) The above formula is based on molecular weights accurate to four significant figures, but it is not to be implied that the dry gas weight
18、 derived has this degree of accuracy. The four digit molecular weights are used to hold errors from calculation procedure to a minimum. COP, 02, and CO = per cent by volume of dry gas. N2 being determined by subtracting the total of COP, 02, and CO from 100 per cent. c, = lb carbon burned lb A.F. fu
19、el = Pounds of carbon burned per pound of “as fired” fuel. Cb =c - (2)In this Code, air leakage is assumed to bypass directly from the inlet air side to the outlet gas side. Therefore moisture in air leakage does not become a part of VGTG, + but does become a part of v/15 t V V,15 - WGI,. 2. Multipl
20、y the result of (1) by the specific humidity (pounds moisture/pounds dry air) to get the pounds of moisture in 3, Add the result of (2) to the vm term used to calculate rV, and then recalculate A L leakage air per pound of “as fired” fuel. ASME PTCmY.3 bd m 0759b70 005Y105 5 m AIR HEATERS Where C= l
21、b carbon lb A.F. fuel = Pounds of carbon in as fired” fuel by laboratory analysis. CI lb wd“P = lb A.F. fuel = Pounds of dry refuse per pound of “as fired” fuel. Where lb Vd) e = F = Dry refuse rate Where refuse rate at various collection points, such as ashpit, dust collector, boiler hoppers, is no
22、t actually determined, it can be estimated if all parties agree. /dlp) = = Laboratory determination of per cent combustible times 14.500 Btu Ib dry refuse per lb or Hdp/ = lb dry refuse = Laboratory determination of heating value by bomb calorimeter 14SOO = - = Heat value of 1 lb of carbon as it occ
23、urs in refuse (see Par. 9.4 of the Test Btu lb Code for Steam Generating Units, PTC 4.1) lb lb A.F. fuel S= = The “as fired” sulfur content of fuel as determined by laboratory analysis. 7.05 lb lb A.F. fuel FrnG = = Pounds of moisture in the flue gas per pound of “as fired” fuel. Wrnc = 8.9368 + (Vm
24、/ X VA I) + m, + W, + IVrn Where 8.936 = 8.936 pounds of water produced from burning one pound of hydrogen. H= lb lb A.F. fuel = Pounds of hydrogen from an “as fired” ultimate analysis, lb lb dry air lb - lb A.F. fuel FmA/ = = Pounds of moisture per pound of dry air at boiler inlet. VA - = Pounds of
25、 dry air per pound of “as fired” fuel as given in Par. 7.06. 23 “-Y- -”- ASME PTCmLI.3 b8 m 0759b70 005LI10b 7 m ASME PERFORMANCE TEST CODES mf = lb A.F. fuel lb = Pounds of moisture per pound of “as fired” fuel. lb wz lb A.F. fuel = Pounds of atomizing steam per pound of “as fired” fuel. The proced
26、ure for obtaining this term is given in Pars, 4.17 and 7.3.2.06 of the Test Code for Steam Generating Units, PTC 4.1. 7.06 lb lb A.F. fuel (VGN - N) ” = = Pounds of dry air per pound of “as fired” fuel. W, = 0.7685 Where lb UGCN = 2 lb A.F. fuel = Pounds of nitrogen in dry gas per pound of “as fired
27、” fuel. 28.02 N2 WGGN2 = 12.01 (CO2 +CO) + 32.07 (c 12-01 S) The preceding formula is based on molecular weights accurate to four significant figures, but it is not to be implied that the weight of dry air has this degree of accuracy. The four digit molecular weights are used to hold errors from cal
28、culation procedures to a minimum. The values used are from the National Bureau of Standards Circular 564, dated 11/1/55. CO, 0, and CO = Per cent by volume of dry flue gas. (Location 14 or 15, Fig. 1.) N2 being determined by subtracting the total of CO2 O2 and CO from 100 per cent. lb . lb A.F. fuel
29、 Cb = = Pounds of carbon burned per pound of “as fired” fuel. Where C= lb lb A.F. fuel = Pounds carbon in “as fired” fuel by laboratory analysis. = lb A.F. fuel lb = Pounds of dry refuse per pound of “as fired” fuel, see Par. 7.04. HdtP# = Heat valuefor dry ref-use from laboratory determination. lb
30、dry refuse (4)For the determinntion of the mean specific heats use PTC 4.1, Fig. 3 for air and Fig. 7 for gas to calculate the weighted average specific heat for wet air and wet gas. AIR HEATERS 14,500 = - = IIeat value of 1 Ib of carbon as it occurs in refuse (see Par. 9.4 of the Test Btu lb Code f
31、or Steam Generating Units, PTC 4.1) lb lb A.F. fuel S= = Pounds sulfur per pound of “as fired” fuel as determined by laboratory analysis. lb lb A.F. fuel N= = Pounds of nitrogen per pound of “as fired” fuel. 0.7685 = Pounds of nitrogen per pound of standard air, then becomes 28.02 N2 12.01 S - N 12.
32、01 (CO, + CO) + 32.01 ) W, = 0.768.5 air passing through the heater to the heat capacity of the gas passing through the heater. lb wet air lb A.F. fuel lb wet gas lb A.F. fuel = Wet air flow leaving air heater. FG,4 r= = Wet gas flow entering air heater as given in Par. 7.03. CPA(4L - lb-F= (4) - -
33、Btu Mean specific heat of air between temperatures tg and te. PG - lb Btu - F - Mean specific heat of gas between temperatures tG14 and tG15 . t14 = F Measured gas temperature entering air heater. tG(5 = F = Calculated gas temperature leaving the air heater with no leakage as given in Par. 7.02. tA9
34、 = F = Measured air temperature leaving air heater. ta = F = Measured air temperature entering air heater, X-Ratio is derived from heat balance taken around an air heater corrected for no air leakage. Using the basic design diagram of Fig. 1, the heat balance is as follows: ASME PERFORMANCE TEST COD
35、ES 17.07.7 Design X-Ratio is obtained by using the above formula and factoring into it the design data. 7 .O8 tc 15 SA = F = Corrected gas temperature leaving air heater for deviation from design entering air temperature. Where AD = F = Design air temperature entering air heater Gl4 = F = Measured g
36、as temperature entering air heater t 15 = F = Measured gas temperature leaving air heater t = F = Measured air temperature entering air heater The above equation is based on the test gas side efficiency remaining constant with changes in inlet air temperature. Its derivation follows: The nonleakage
37、leaving gas temperature t15 FA is the corrected variable to be solved for. This temperature is related to the leaving gas temperature with leakage as shown by Par. 7.02. The two equations for the two nonleakage leaving gas temperatures in the above equation are shown as follows: Rew riting the above
38、 equation to correct for the deviation from design entering air temperature. kt5 6A = k (G15 SA - tAsD) + tG156A Upon substitution of the above two nonleakage leaving gas temperature equations into the equated gas side efficiency equation, the corrected leaving gas temperature with leakage tlj FA ca
39、n be solved for. The result of this substitution is as follows: kl4 - k(t15 - tA8) - tG15 - G14 - k(t156 - LAsD) - tGt58A - tG14 - LA8 kt4 - tA8D AIR HEATERS The above equation reduces to: 7.09 t15 SG = F = Corrected Gas Temperature Leaving Air Heater for Deviation from Design Enter- ing Gas Tempera
40、ture “here tC14 = F = Design gas temperature entering air heater t 15 = F = Measured gas temperature leaving air heater AE = F = Measured air temperature entering air heater t14 t F = Measured gas temperature entering air heater The above equation is based on the test gas side efficiency remaining c
41、onstant with changes in inlet gas temperature. The derivation follows: The nonleakage leaving gas temperature tG 15 is the corrected variable to be solved for. This temperature is related to the leaving gas temperature with leakage as shown by Par. 7.02. The two equations for the two nonleakage leav
42、ing gas temperatures in the above equation are shown below: Upon substitution of these nonleakage leaving gas temperature equations into the equated gas side ef- ficiency equation, the corrected leaving gas temperature with leakage tG15 6 can be solved for. The result of this substitution is shown b
43、elow ASME PERFORMANCE TEST CODES 7.11 t158 = .F = Corrected Gas Temperature Leaving Air Heater for Deviation from Design Entering Flue Gas Flow. Correction to measured gas temperature leaving the air heater for deviation from design flue gas flows may be made by the use of appropriate design correct
44、ion curves. (5) 7.12 t158Tl =. F = Totally corrected gas temperature leaving air heater tG156l = tG158A $. tG158G + k158 + tG158“tGl5 Where G15 SA = F = Gas temperature leaving the air heater corrected for deviation from design entering air temperature tG 15 8G = F = Gas temperature leaving the air
45、heater corrected for deviation from design entering gas temperature 7.13 t15 8 = F = Gas temperature leaving the air heater corrected for deviation from design X-Ratio t 15 8 = F = Gas temperature leaving the air heater corrected for deviation from design gas flow G 15 = F = Measured gas temperature
46、 leaving the air heater. lb “ O = lb of A.F. fuel = Corrected Air Leakage for Deviation from Design Pressure Dif- ferential and from Design Air Temperature Where lb “ O = lb of A.F. fuel G= KG15 - wG4 = Air leakage AIR HEATERS Where lb wet gas leaving/entering air heater lb A.F. fuel wG15,14 = = IvG
47、15,14 VmG (6 1 lb dry gas lb A.F. fuel = = Dry gas flow leaving/entering the air heater as given in Par. 7.04 ll.,G = lb moisture lb A.F. fuel 7.0s = Total moisture in flue gas entering the air heater as given in Par. Ap(8-15) = Inches of water = Design static pressure difference between air inlet a
48、t the duct connection flange and gas outlet at the duct connection flange. AP(8-15) = Inches of water = Measured static pressure difference between air inlet at the duct connection flange and gas outlet at the duct connection flange. TAS = R = Measured average Rankine temperature of air entering air
49、 heater. TAD = R = Design Rankine temperature of air entering air heater. It is recognized that the above orifice correction is not a rigorous treatment of the subject but is con- sidered sufficiently accurate for the purpose of the Code. 7.73.7 To determine the above corrections when leakage is expressed on a percentage basis, use the following procedure: A 80 = Per cent = Corrected Air Leakage for Deviation from Design Pressure Differential and from Design Air Temperature Wher
