1、Determination of emissions from appliances burning gaseous fuels during type- t es t ing . , -.L - . -.- ,- - -_ _.- . . . _I . . -. -. .“ .I, .- Cooperating organizations of the Standards bard and Amd. No. comes into effect on 15 September 1994 “he European Committee for Standardization (CEN), unde
2、r whose supervision this Report was prepared, comprises the national standards organizations of the following countries: l, -,.,- Date Austria Belgium Denmark Finland France Germany Greece Iceland Ireland Luxembourg Netherlands Norway Portugal Spain Sweden Switzerland United Kingdom Italy The follow
3、ing ES1 references relate to the work on this standard: Committee reference GSE,- Oesterreichisches Normungsinstitut institut belge de normalisation Dansk Standard Suomen Standardisoimikiito, r.y. Association francaise de normalisation Deutsches institut fr Normung e.V. Hellenic Organization for Sta
4、ndardization Technological Institute of Iceland National Standards Authority of Ireland Ente Nazionale Italiano di Unificazione Inspection du Travd et des Mines Nederlands Norm - - The conservation characteristics of the calibrating gases shall be declared by the manufacturer for a minimum period wh
5、ich shall nt be less than 1 year. N2 is used for all analyzers for zero point control ; for the low ranges special attention should be paid to the purity of the N2 gas ; NO2 in air or NO2 generator for testing the normal operation of the converter ; CO, CO2 and O2 in N2. Cylinders shall not be opera
6、ted at a pressure less than 5 bar. 3. Accuracy of the calibration gases The primary calibration gas used must be certified and traceable to an international standard, or to a national standard applicable to them in so far as in this area no harmonised standard exists. It is advisable to use calibrat
7、ion gases with an accuracy of 1 or 2% of the given value. This depends on the application (linearity check and span check). Note : - weighing methods for the preparation of calibration gas mixtures are indicated in IS0 6142 ; - gas analysis calibration gas mixtures certificates of guarantee are ali
8、indicated in IS0 6141. F. PERIODICAL CHECKS - The sampling transport line shall be checked at least once a month for leakage and changing in composition of the sampling gas to the analyzer, by introducing calibration gas (e.g. NOZ) at atmospheric pressure consecutively at points 1 and 7 of fig. 1. -
9、 At least once a week check the efficiency of the converter, which should be at least 90%: If the efficiency of the converter is 95%, no correction is necessary, provided that the total allowable systematic error is not exceeded. 1624669 0500052 964 M 2- .- Page 6 CR 1404 : 1994 - At least once a ye
10、ar or after repair the analyzers shall be checked for linearity ; where there is some doubt then rt is essential to compare the analyzer with calibration gases or with an independent method such as the wet chemical method. G. SAMPLING LINE 1. Introduction Three methods could apply : - - wet sampling
11、 method ; - dilution method. water vapour removal methods ; Note : the dilution method should not be used for type testing of gas appliances ; therefore this sampling method is not described in this dmument. 2 General The sample of combustion products shall be representative of the average of combus
12、tion products inside the duct section. Therefore, the probe of fig. 2, 3 and 4 for flued appliances, or probe of fig. 6 for balanced flue appliances, IS used. The location of the sampling probe system is indicated in figures 5, 7 and 8. Sampling probes to atternative standards will be acceptable pro
13、vided that the homogeneity of the sample can be confirmed. 2.1. Samplina orobe The sampling probe is constructed of stainless steel or glass. 2.2. Response time The time between applying the calibration gas mixure (at point 1, fig. 1) and reaching 90 % of the recorded max concentration, shall not ex
14、ceed 200 s including probe and 1 3 sampiingline. 3. Description and arrangements of the water vapour removable method 3.1. Minimum temperature Upstream of the dryer the sampling line shall be kept at least 1SK above the water and acid dewpoint temperature of the sampled gas. A temperature control is
15、 required to keep the line temperature constant. 3.2. TransDort line To transfer the sample to the analyzers either stainless steel or PTFE (Teflon) tubes are used ; their diameter depends on the required quantw of sampled gas but shall not be smaller than 4 mm(preferab1e 4 to 8 mm). Rubber of silic
16、on materials shall not be used. mm lib24669 0500053 BTO m , - Page 7 CR 1404 : 1994 3.3. 3.4. 3.5. 3.6. 3.7. Cooler or permeation dryer Parts of the cooler in contact with the sample shall be made of glass, Teflon or stainless steel. Cooling must be sufficient for the gas quantity and the water conc
17、entration. The dewpoint shall be sufficiently below the ambient temperature. A cooling temperature of 2 to 5“ is sufficient. It is essential to remove condensates as efficiently as possible in order to minimise the contact with the sample and the absorption of NOZ. Desiccant shall not be used. Note
18、: - - when the condensationlrefrigeration metha is used, the removal shall take place outside the heated box. where permeation drying is employed, half of the dryer tube (wet) shall be heated to at least 15K above the gas dewpoint. The manufacturers recommendations on the quantity or purge air shall
19、 be followed. A fitter shall be positioned between the cooler and the manifold. The housing is constructed of stainless steel or glass, and its size shall be determined from the required sample flow and the manufacturers data on the flow rate per unit area. The sinter metal, PTFE-fibre, or quartz fi
20、tter shall retain particles not greater than 1 m. Note : - care should be taken to avoid contamination of the filter wtth particles where particulate material may react with gases to give an erroneous result. Manifold The manifold shall be constructed of stainless steel or Teflon with a separate con
21、nection for each anaiyzer. It shall be of sufficient site to accommodate the gas flow required by each analyzer, but small enough to keep the gas residence times to a minimum. The exhaust of sample must be vented. Row meter In order to check the exact flow, a flow meter made of a suttable corrosion
22、resistant material is necessary. Samdina DumD Parts of the sampling pump in contact with the gases, shall be constructed either of Teflon, stainless steel or viton. The capacrty of the pump shall be such that it can supply all the analyzers with their required flows, plus a 10% excess flow margin. 4
23、. Wet sampling The requirements and description are the same as for the water vapour remova1 method taking into account following considerations : - - . upstream of the analyzer the sampling line shall be kept at least 15 K above the water and - A correction for the water vapour in the sample must be made (see Annex 1 - Conversion - Calculation). no cooler is present in the sampling line, acid dewpoint temperature of the sampled gas, the analyzer has to be especially designed for that method.
