GB/T 39809-2021Measuring method of the energy consumption of flat glass furnace (English PDF)

3.1 Energyconsumptionoffurnace

The energy consumed per kilogram of molten glass by the furnace during the measurement period.

4.1 Direct method

The direct method is to calculate the energy consumption of the kiln based on the consumption of fuel, the heating value and the electricity consumed by the electric booster. In fuel consumption and fuel calorific value The direct method is used in certain cases.

4.2 Indirect method

The indirect method is to calculate the energy consumption of the kiln by measuring the heat balance of the kiln system. When fuel consumption or fuel calorific value cannot be accurately determined Under the circumstances, the indirect method should be used.

5.1 Testing period and requirements

The measurement period is the actual statistical period, and the measurement requirement is continuous and stable production of the furnace.

5.2.1 Determination of fuel consumption

The amount measured by the measuring instrument, the measuring instrument meets the requirements of GB/T 24851.

5.2.2 Determination of calorific value

The value on the test report issued by a correspondingly qualified testing organization should be preferred, and the value published by the country can also be used (see Appendix A).

5.3 Determination of electric boosting heat

The electricity consumption is determined according to the reading of the electric meter, converted into energy according to the coefficient of electricity converted into standard coal, and calculated according to formula (1). Qd=W ×A×29271.2 (1) Where. Qd---Electric boosting heat, in kilojoules (kJ); W --- Electricity consumption, in kilowatt hours (kWh);

A ---The coefficient of power conversion into standard coal, which is 0.1229kgce/(kW·h).

5.4 Determination of the quality of molten glass

Take the quality of the molten glass obtained by statistics during the measurement period.

5.5 Calculation method

Take the fuel consumption, calorific value, electricity and glass liquid quality during the measurement period, and calculate the energy consumption according to formula (2). E=(mr×Qdw Qd)/mb (2) Where.

E --- Kiln energy consumption, in kilojoules per kilogram (kJ/kg); mr --- fuel consumption, in kilograms (kg); Qd --- Electric boosting heat, in kilojoules (kJ);

Qdw---low fuel calorific value, in kilojoules per kilogram (kJ/kg); mb---the mass of molten glass in kilograms (kg).

6.1 Measuring principle of indirect method

According to the principle of energy balance, by measuring the total energy of the output system, the total energy of the input system is obtained. Kiln system energy balance frame The figure is shown in Figure 1.

The tolerance of the galvanic couple meets the requirements of GB/T 16839.1.

6.6.1.3 Determination of the quality of molten glass

Use a steel tape to measure the width of the original glass plate, and use an outside micrometer to measure the thickness of the original glass plate. Steel tape measure conforms to QB/T 2443 Degree, outer diameter micrometer conforms to GB/T 1216, the graduation value is 0.01mm.

Calculate the quality of molten glass according to formula (3). mb=Vb×Bb×hb×rho (3)

Where. mb---the mass of molten glass in kilograms per hour (kg/h);

Vb --- the pulling speed of the glass sheet, in meters per hour (m/h);

Bb --- the width of the original glass plate, in meters (m); hb --- the thickness of the glass plate, in meters (m);

rho ---Glass density, the unit is kilogram per cubic meter (kg/m3).

6.6.1.4 Calculation method

Calculate the sensible heat brought by the molten glass according to formula (4). Qbx=mb×cbc×tbc (4) Where.

Qbx---The molten glass brings out the sensible heat Qbx, in kilojoules per hour (kJ/h); mb---the mass of molten glass in kilograms per hour (kg/h); cbc --- The average specific heat capacity of molten glass at 0~tbc, in kilojoules per kilogram degrees Celsius [kJ/(kg·°C)], see calculation method Appendix B; tbc --- the temperature of the molten glass in the system, in degrees Celsius (°C).

6.6.2 Determination of latent heat from molten glass

6.6.2.1 Measurement parameters

The quality of the molten glass and the water content per kilogram of the batch.

6.6.2.2 Determination of the quality of molten glass

Same as 6.6.1.3.

6.6.2.3 Determination of water content per kilogram of batch

Take a sample and measure at the feed opening of the raw material mixer, and measure it in accordance with JC/T 648, measure it three times a day, and take the average.

6.6.2.4 Calculation method

According to formula (5), calculate the latent heat of molten glass. qiKhi 347×Kbf× 1-Kfq() 2491×Kbf×KH2O] (5)

6.6.5.1 Measurement parameters

The temperature and composition of the orifice overflow gas, and the static pressure difference between the inside and outside of the orifice gas.

6.6.5.2 Measurement of gas temperature and composition

The gas temperature is measured with a thermocouple thermometer combined with a corundum protection sleeve single platinum rhodium thermocouple and a temperature display instrument, and the accuracy is shown in 6.6.1.2.

Use Austrian gas analyzer or other equivalent instruments to determine the composition of O2, CO, and CO2; use constant-potential electrolysis or non-dispersion A portable gas analyzer for testing based on the principle of the infrared method to determine the NOx composition; using the conductivity method, constant potential electrolysis method, and non-fractional A portable gas analyzer for testing based on the principle of diffuse infrared method to determine the SO2 composition.

6.6.5.4 Calculation method

The sensible heat of the orifice overflow gas is calculated according to formula (12). Vyi×cyi×tyi() (12) Where.

Qky---the sensible heat of the orifice overflow gas, in kilojoules per hour (kJ/h);

Vyi---the amount of gas overflowing from the orifice, in cubic meters per hour (m3/h), calculated according to formula (13); cyi --- The average specific heat capacity of the orifice overflow gas at 0~tyi°C, in kilojoules per cubic meter Celsius [kJ/(m3·°C)], press Formula (14) calculation; tyi --- orifice overflow gas temperature, in degrees Celsius (°C). Vyi=±3600×Ski×ui× 2× deltapki × p deltapki()×273 rho0×101325× tyi 273() (13) Where.

Ski --- the area of the i-th orifice of the kiln body, in square meters (m2); ui --- the overflow coefficient of the orifice, When delta>=3.5de, ui=0.82; When delta< 3.5de, ui=0.62;

delta --- the thickness of the kiln wall at the overflow orifice, in meters (m); de --- The equivalent diameter of the overflow orifice, in meters (m);

deltapki --- the static pressure difference between inside and outside the orifice, in Pa (Pa); when deltapki is positive, Vyi takes a positive value; when deltapki is negative, Vyi takes Negative value; p ---Atmospheric pressure, the unit is Pa (Pa);

rho0 ---The density of the gas in the standard state, in kilograms per cubic meter (kg/m3), calculated according to formula (15); tyi --- orifice overflow gas temperature, in degrees Celsius (°C). cyi=0.01sumXicpi (14) Where.

Xi --- the content of each component in the gas (volume fraction), %; cpi --- The average constant pressure specific heat capacity of the i-th component in the gas, in kilojoules per cubic meter Celsius [kJ/(m3·°C)], see Appendix C Table C.1, Table C.2. rho0=0.01sumXirho0i (15) Where.

Xi --- the content of each component in the gas (volume fraction), %;

rho0i --- The density of each component in the gas under standard conditions, in kilograms per cubic meter (kg/m3).

6.6.6 Determination of heat taken by cooling water

6.6.6.1 Measurement parameters

The flow of cooling water, the temperature of cooling water in and out.

6.6.6.2 Measurement of cooling water flow

Use a portable ultrasonic flowmeter to measure or install a water meter on the water inlet pipe. The accuracy level of the portable ultrasonic flowmeter should not be low Below 1%, the accuracy grade of the water flow meter (water meter) should not be less than 1%.

The installation and measurement points of the portable ultrasonic flowmeter should meet the following requirements.

---Select a pipe section filled with fluid that is uniform and dense, and is easy to transmit ultrasonic waves.

---The installation distance should be greater than 10 times the straight pipe diameter in the upstream and 5 times the straight pipe diameter in the downstream without any valves, elbows, reduced diameters, etc. Uniform straight pipe section.

6.6.6.3 Determination of cooling water temperature

Use a glass thermometer to directly measure the temperature of the cooling water in and out.

6.6.6.4 Calculation method

The heat carried by the cooling water is calculated according to formula (16). Qls=4.1868×mls×(t'ls-tls) (16) Where.

Qls---cooling water brings out heat, in kilojoules per hour (kJ/h); mls-the amount of cooling water entering and leaving the system, in kilograms per hour (kg/h); t'ls---The temperature of the cooling water when exiting the system, in degrees Celsius (°C); tls --- The temperature of the cooling water when entering the system, in degrees Celsius (°C).

6.6.7.1 Measurement parameters

The cross-sectional area, dynamic pressure, static pressure, gas velocity of the flow section, the temperature of the cooling air before blowing to the kiln, and the temperature of the reflected air after blowing to the kiln.

Parallel to the gas flow direction in the pipeline, the maximum allowable deviation angle shall not be greater than 10°.

6.6.7.3 Measurement of cooling air temperature

The temperature of the cooling air before blowing to the kiln is measured at the inlet of the fan with a glass thermometer with the smallest division value not greater than 1°C, after blowing to the kiln.

The reflected air temperature is measured at the cooling air nozzle with an exhaust thermocouple, and the displayed error value of the exhaust thermocouple should not exceed ±3°C.

6.6.7.4 Calculation method

Measure with Pitot tube and calculate the cooling air flow according to formula (17). Vlf=3600×Sd×Kd deltapi n × 2× p pj()×273 rho0×101325× 273 tq() (17) Where.

Vlf --- cooling air volume, in cubic meters per hour (m3/h);

Sd --- the area of the flow cross section, in square meters (m2); Kd --- Pitot tube correction factor;

deltapi---the dynamic pressure value of the i-th point in the flow section, in Pa (Pa); n --- the number of measuring points in the flow section; p ---Atmospheric pressure, the unit is Pa (Pa); pj --- the static pressure in the flow section, in Pa (Pa);

rho0 ---The density of the gas in the standard state, in kilograms per cubic meter (kg/m3); tq --- The average temperature of the gas in the flow section, in degrees Celsius (°C).

Measure with a hot ball anemometer, and calculate the cooling air flow according to formula (18). omegai n × 273 tk× p pj 101325×Sd (18) Where. Vlf---cooling air volume, in cubic meters per hour (m3/h);

omegai---the gas velocity at the i-th point in the flow section, in meters per second (m/s); n --- the number of measuring points in the flow section; tk --- The average temperature of the gas in the flow section, in degrees Celsius (°C); p ---Atmospheric pressure, the unit is Pa (Pa); pj---static pressure in the flow section, in Pa (Pa);

Sd---The area of the flow cross section, in square meters (m2).

The heat carried by the cooling air is calculated according to formula (19). Qlf=Vlf×(c'lf×t'lf-clf×tlf) (19) Where. Qlf---cooling air brings out heat, in kilojoules per hour (kJ/h);

Vlf---cooling air volume, in cubic meters per hour (m2/h); c'lf---0~t'lf average specific heat capacity of cooling air, in kilojoules per cubic meter Celsius [kJ/(m3·°C)], refer to Appendix C Table C.1; t'lf---Reflected wind temperature after blowing to the kiln body, in degrees Celsius (°C); clf---0~tlf The average specific heat capacity of the cooling air, in kilojoules per cubic meter Celsius [kJ/(m3·°C)], refer to Appendix C, Table C.1; tlf --- The temperature of the cooling air blowing to the kiln body, in degrees Celsius (°C).