NB/T 34036-2020Test method for small biomass boiler (English PDF)

3.1 Rated heating power

The boiler can continuously produce heat per unit time when the boiler is at rated parameters, rated flow, using design fuel, and ensuring efficiency.

3.2 Heat input

The total heat input into the boiler by the biomass briquettes.

3.3 Heat output

The difference between the heat provided by the boiler through the hot water and the heat brought by the water entering the boiler.

3.4 Thermal efficiency

The percentage of boiler output heat to fuel input heat at the same time is also called positive balance efficiency.

5.1 Test preparation

5.1.1 The person in charge of the test shall be someone who is familiar with this document and has experience in boiler thermal testing. The person in charge of the test shall be based on the relevant provisions of this document.

It is stipulated that the test outline shall be formulated according to the specific situation and the implementation of the test outline shall be organized. The test outline includes.

a) Test purpose and task;

b) Test requirements;

c) Measurement items;

d) Layout of measuring points and instruments and equipment used;

e) Test personnel organization and division of labor;

f) Test schedule and progress;

g) Matters needing attention and others.

5.1.2 Before the test, check whether the operating conditions of the boiler and auxiliary equipment are normal. Any abnormality should be eliminated.

5.1.3 Install meters and test equipment in accordance with the requirements of the test program.

5.1.4 Before the formal test, a preliminary test should be carried out according to the test requirements and test content to comprehensively check whether the meter and the test equipment are correct.

Often work, familiar with the test operation and the mutual cooperation of personnel.

5.2 Test requirements

5.2.1 The formal test should start after the boiler is adjusted to the test conditions and runs stably.

5.2.2 The test conditions of the boiler should meet the following requirements.

a) The difference between the boiler outlet water temperature and the design value should not exceed ±5°C;

b) The fluctuation of the rated heating power of the boiler during the test should not exceed 10%.

5.2.3 At the end of the test, the level of the fuel hopper, the thickness of the fuel layer, and the combustion conditions should be consistent with those at the beginning of the test.

5.2.4 During the test, the excess air coefficient, fuel supply, water inlet and outlet, fuel layer thickness, combustion conditions, etc. should be basically the same.

5.2.5 The inlet water temperature and outlet water temperature of the boiler shall be recorded every 5 minutes, and other items shall be recorded every 10 minutes.

5.2.6 Test times, time and error a) The finalization test of the new product should be carried out twice under the rated heating state, and the number of tests for other purposes shall be negotiated with the user;

b) The duration of each thermal performance test should not be less than 3h;

c) The rated thermal power measured in the two tests should not be less than 97% of the nominal value;

d) The difference in thermal efficiency between the two tests should not exceed 3%.

5.2.7 The instruments used in the test shall have a verification certificate issued by a legal metrological verification agency and shall be within the validity period of verification or calibration.

Inside. The installation and use of the instrument should comply with its product manual and relevant regulations. The meter should be checked before and after the test.

5.2.8 The test environment should be 10°C~30°C, if it is an open-air boiler, it should avoid direct sunlight, wind speed greater than 5m/s or rain The test should be stopped every day.

5.2.9 For biomass sampling into the furnace, the amount of original sample collected for each test should not be less than 1% of the total fuel consumption, and the total sampling amount is quite large Less than 10 kg. Sampling should be carried out at the weighing location, and the sampling and preparation methods should be carried out in accordance with NY/T 1879 and NY/T 1880.

5.3 Test instrument and installation

5.3.1 The fuel consumption is measured by a platform scale, and the accuracy level of the platform scale is Class III.

5.3.2 The water output (or water intake) is measured with a calibrated water tank or a flow meter is installed on the boiler water inlet pipe. The accuracy of the flow meter The degree level should not be lower than 0.5.

5.3.3 The temperature measuring points of the thermometers for the outlet water temperature and the inlet water temperature should be arranged on the pipeline where the water temperature is relatively uniform, and the thermometer reading resolution It is 0.2°C.

5.3.4 For thermometers that measure the exhaust gas temperature, the accuracy level of the display meter shall not be less than 0.5. The measurement point of the exhaust gas temperature should be close to the end The distance of a section of heating surface should not be greater than 1 m.

5.3.5 The thermometer for measuring the ambient temperature should be placed near the boiler to be tested, and the reading resolution of the thermometer should be 0.2°C.

5.4 Calculation of test results

5.4.1 The rated thermal power is calculated according to formula (1). Where. Pn-rated thermal power, in megawatts (MW);

Gz-total water output, in kilograms (kg); tcp-the average temperature of the total effluent, in degrees Celsius (°C); tjp-the average temperature of the total inlet water, in degrees Celsius (°C); T2-T1 - Test time, in seconds (s).

5.4.2 The thermal efficiency is calculated according to formula (2). Where. eta-thermal efficiency;

B - Biomass fuel consumption during the test period, in kilograms (kg);

Qnet.v.ar - The received base low calorific value of biomass briquettes, in kilojoules per kilogram (kJ/kg).