ISO-7841-1988.pdf
《ISO-7841-1988.pdf》由会员分享,可在线阅读,更多相关《ISO-7841-1988.pdf(14页珍藏版)》请在三一文库上搜索。
1、INTERNATIONAL STANDARD INTERNATIONAL ORGANIZATION FOR STANDARDIZATION ORGANISATION INTERNATIONALE DE NORMALISATION MEXAYHAPOJJHAR OPrAHM3AuMR l-l0 CTAHAAPTMBAklkl Automatic steam traps - Determination of steam loss - Test methods Purgeurs automatiques de vapeur deau - D or the average result from th
2、ree consecutive tests shall agree within 10 % or 500 g/h, whichever is the greater. If this cannot be obtained, check the system for integrity and increase the calorimeter tank capacity. 4.1.2 Load condition Start with all valves closed and both tanks empty. 4.1.2.1 Open valves 1, 2 and 3 to permit
3、the drain and test devices to operate at test pressure ps. 4.1.2.5 Fill the calorimeter tank with sufficient water (about half-full) to result in a test run of practical duration. The initial water temperature 0, should be at least 8 ?I below ambient temperature 0,. Record the water temperature 8, a
4、nd mass of water plus tank ml. 4.1.2.6 When thermal equilibrium is reached, simultaneously and rapidly close valve 3, and open valve 4, and start the timing interval. The use of a three-way valve is recommended to facilitate rapid closing and opening. 4.1.2.7 Stir the water in the calorimeter tank a
5、s necessary to ensure a uniform water temperature. 4.1.2.8 When the temperature of the water in the calorimeter tank is as many degrees above ambient as the initial temperature was below, rapidly close valve 4 and open valve 3 simultaneously, record the elapsed time, the final water temperature e2 a
6、nd the mass of water plus tank m2. 4.1.2.9 Before the measurement, trial runs should be carried out to ensure that the tesf conditions have stabilized and that the pressure, temperature, initial amount of water in the calorimeter tank and load conditions are those required. When testing condensate r
7、emoval devices, an error calculation is made from three consecutive tests to determine the accuracy of the test result. The error calculation is based on the instrumentation used and described in this International Standard; or the average result from three consecutive tests shall agree within 10 %
8、or 500 g/h, whichever is the greater. 1) 1 bar = 105 Pa 3 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/22/2007 21:25:16 MDTNo reproduction or networking permitted without license from
9、 IHS -,-,- IS07841 : 1988 (E) If this cannot be obtained, check the system for integrity and mf is the final mass of water and condensate in the increase the calorimeter tank capacity. calorimeter, in kilograms; 4.2 Expression of results 4.2.1 Correction of measured variables The values of observed
10、variables shall be corrected in accord- ance with instrument calibrations and, if necessary, converted to the proper units required for calculations. 4.2.2 Use of formula symbols The symbols used in this International Standard are the ones normally associated with engineering practice in this field.
11、 In a few cases, the same symbol has different meanings in different parts of this International Standard according to its application. In order to avoid confusion, each formula has been provided with its own list of definitions of symbols and units. 4.2.3 Computation formula 4 ms = -hk (mf-mi) +cpm
12、, W2-01) hfgs 1 3600 x- At where qms is the steam loss, in kilograms per hour; mr is the initial mass of water in the calorimeter, in kilograms; ml is the mass of calorimeter plus water, at the start, in kilograms; m2 is the mass of calorimeter plus water, at the finish, in kilograms; m, is the mass
13、 of calorimeter tank, in kilograms; hf, is the initial specific enthalpy of water in the calorimeter, in joules per kilogram; hf2 is the final specific enthalpy of the condensate and water in the calorimeter, in joules per kilogram; hfs is the specific enthalpy of the liquid at steam inlet con- diti
14、ons, in joules per kilogram; hfgs is the specific enthalpy of the evaporation at steam in- let conditions, in joules per kilogram; cP is the specific heat of the calorimeter material, in joules per kilogram kelvin; 0, is the initial water temperature in the calorimeter tank, in degrees Celsius; 8, i
15、s the water temperature in the calorimeter tank, in degrees Celsius; At is the time interval, in seconds. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/22/2007 21:25:16 MDTNo reproduct
16、ion or networking permitted without license from IHS -,-,- IS0 7841 : 1999 (EI 4.3 Data sheet Test Method A General information 1 TestNo. 2 Testdate: . 3 Location: . 4 Manufacturersname: 5 SerialNo.: 6 Typeofdevice: 7 Size: . 8 Calorimetermaterial: . . 9 Massofemptycalorimeter,mt= . . . . . . . . .
17、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Averaged and corrected test data 10 11 12 13 14 15 16 17 16 19 Mass of calorimeter plus water, start, ml = . kg Massofcalorimeterpluswater,finish,m2= kg M
18、assaddedtocalorimeter,Am = . kg Item 11 - Item 10 TimeintervaLAt = . S Ambient temperature, 0, = . OC Steam temperature at trap inlet, 8, = OC Initial wafer temperature in calorimeter tank, 61 = OC Final temperature of wafer and condensate in calorimeter tank, e2 = OC Barometric pressure, pa = . bar
19、 Steam pressure at trap inlet, ps = . bar Thermodynamic properties 20 Referenceusedforspecificheafdata:., 21 Referenceusedforsteam/waferdata: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 S
20、pecific heat of calorimeter material, cP = . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . , . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . . J/(kg.K) (from Item 20 for Item 8 at average of Items 16 and 171 23 Initial specific enthalpy of water in calorimeter, hf, =
21、. L. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . , . . . . . . . . . . J/kg (from Item 21 at Item 16) 24 Final specific enthalpy of water in calorimeter, hf2 = . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . J/kg (from Item 21 at Item 17)
22、 25 Specific enthalpy of saturated liquid at trap inlet temperature, hf, = . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . J/kg (from Item 21 at Item 15) 26 Specific enthalpy of evaporation at trap inlet temperature, hfgs = . . . . . . . . . . . . . . . .
23、. , . . . . . . , . , , . . . . . . . . , . . . . . . . . . . . . J/kg (from Item 21 at Item 15) Calculations 27 Initial mass of water in calorimeter, Mr = . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . * kg Item 10 - Item 9 28 Final mass of water and condensate in
24、 calorimeter, mf = . . . . . . . . . . . . . . . . . . . . . . . . * kg Item 11 - Item 9 29 Initial enthalpy of water in calorimeter tank, mihfl = . . . . . . . . . . . , . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . , . . . . J (Item 27) x (Item 23) 30
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- ISO 7841 1988
链接地址:https://www.31doc.com/p-3780469.html