BS EN 304:2017 download.Heating boilers – Test code for heating boilers for atomizing oil burners.
1 Scope
BS EN 304 applies to the determination of the performances of heating boilers and combi boilers fired by liquid fuels. The requirements for the heating performances are laid down In EN 303-1:201? and EN 303-2:2017.
This test code includes the requirements and recommendations for carrying out and evaluating the procedure for testing boilers and also the details of the technical conditions under which the tests will be carried out.
The requirements and the performance of testing for the sanitary hot water production of combi boilers are laid down in prEN 303-6.
2 Normative references
The following documents, in whole or in part, are normatively referenced in BS EN 304 and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
EN 267:2009+A1 :2011. Automatic forced draught burners for liquid fuels
EN 303-1:2017. heatIng boilers- Part 1: Heating boilers with forced draught burners- Terminology. general requirements, testing and marking
EN 303-2:2017, Heating boilers Part 2: HeatIng boilers with forced drought burners Special requirements for boilers with atomizing oil burners
prEN 303-6. HeatIng boilers – Part 6: HeatIng boilers with forced drought burners Specific requirements for the domestic hot water operation and energy performance of water heaters and combination boilers with atomizing oil burners of nominal heat input not exceeding 70 kW
EN 15456, Heating boilers- Electrical power consumption for heat generators – System boundaries. Measurements
EN ISOIIEC 17025. General requirements for the competence of testing and calibration laboratories
(ISO/IEC 17025)
3 Terms and definitions
For the purposes of BS EN 304, the terms and definitions given in EN 303-1:2017 and EN 303-2:2017 and the following apply.
minimum continuous heat output
lowest heat output which is maintained automatically by the control device in continuous operation which is specified for each type of fuel in accordance with the requirements of this European Standard
4 General conditions for testing
The performance tests of the boiler shall be carried out by a test laboratory complying with the requirements of EN ISO/IEC 1702S.
The test sample shall correspond to a boiler as placed on the market including all parts and accessories necessary for the operation of the boiler. Rollers to be equipped with different burners shall be tested with one specified forced draught burner.
The full range of the measurmg apparatus shall be chosen in such a way that it is suitable for maximum anticipated value. The measurement accuracies Indicated above concern Individual measurements.
For measurements requiring a combination of individual measurements, the lower accuracies associated with individual measurements may be necessary to attain the total required uncertainty. The test rig shall be set up In such a way that the efficiency can be determined within a uncertainty of 2% points.
6 Measurements for the heating mode
6.1 General
The amount of useful heat output transmitted to the heat carrier (water) Is measured. It can be determined in the boiler circuIt or by means of a secondary heat exchanger.
The useful heat output transmitted to the water is determined either by measuring
a) the mass flow of cold water entering the boiler circuit and the rise of temperature between the outlet water temperature and the inlet water temperature; or
b) the mass flow of the water circulating in the boiler circuit and Its temperature rise: or
c) the mass flow and the temperature rise over a secondary heat exchanger corrected by the heat loss of this secondary heat exchanger. The heat produced by the boiler Is transferred to the cooling water by means of a secondary heat exchanger. The heat received by the latter is calculated from the mass flow and the temperature rise of the cooling water. The heat losses from the we1l Insulated connections between the boiler and the secondary heat exchanger and those of the secondary heat exchanger itself, are determined either by preliminary tests or by calculation. The heat output of the boiler Is the sum of the two amounts of heat.
6.2 DeterminatIon of the nominal heat output
The tests for the determination of the nominal heat output shall be carried out at a firing rate such that the output is at least 100 %. but does not exceed 105 % of the nominal value, and the requirements concerning the nominal heat output shall be met.
If the heat output exceeds 105%, a second test shall be carried out at a firing rate between 95 % and 100 % of the nominal heat output of the boiler,
The actual value for the nominal heat output shall be determined by linear interpolation between the two test results.
The nominal heat output shall be determined at a water rate that is adjusted to obtain a return water temperature of (60 t 1) C and a temperature difference between the flow and return water temperature of (20 ± 2) °C.
NOTE The conditions for determination of the rated heat output in Former versions of EN 304 have been a mean flow temperature of between 80 C and 90 C. and the mean temperature difference between flow and return has been between 10K and 25 K. However, this Is not in line with the Regulation EU 813/2013.
6.3 DetermInation of the boiler efficIency at nominal heat output
The boiler efficiency at nominal heat output is measured as the determination of the nominal heat output (see 6.2).
The efficiency shall be determined on the basis of the net calorific value NCV.
The direct method according to 6.5.4.1 shall be applied. The Indirect method allows an additional check of test accuracy of the test rig to be made by means of an energy balance.
8 Test report and other documents
Test reporting shall be Issued on the basis of EN ISO/IEC 17025 requirements. The test report shall include at least:
a) name and address of the test laboratory and the location were the tests have been carried out;
b) identification number of test report;
c) name and address of customer
d) test method;
e) description of the boiler or the series of boilers which are tested including:
1) general construction;
2) safety devices with Identification (type, certification, supplier, adlustment, size);
3) relevant components;
4) burner;
5) parts list (where appropriate);
6) period of testing;
7) test results;
8) picture of the boiler.
The following documents shall be provided to complete the test documentation:
— drawings showing clearly the material, welding (where appropriate) and wall thickness of pressurized parts;
— installation and operating manual as well as other relevant documents of the manufacturer
— a description of the boiler including the draft of the boiler data plate. The test report shall not be published in abbreviated form.