GB/T 15914-2021Monitoring and testing method for energy saving of steam heating equipments (English PDF)

1 Scope

GB/T 15914-2021 is the Chinese national standard on monitoring and testing method for energy saving of steam heating equipments, in the field of energy and heat transfer engineering. The /T suffix marks it as a recommended standard: it is not compulsory by itself, but it becomes binding as soon as a contract, a tender or a customer specification calls it up - which in practice is how most foreign buyers meet it. It was issued on 9 March 2021 by the State Administration for Market Regulation; Standardization Administration of China, and has been in force since 1 October 2021. Classification: ICS 27.010, CCS F01. This page is published from the official record of the standard held by the Chinese standards administration: the identification, the dates, the classification and the issuing body are taken from there. The clause text, the tables and the numeric limits are in the document itself, which is delivered complete in English translation.

This standard specifies energy-saving monitoring methods, energy-saving monitoring content and energy-saving monitoring evaluation indicators for energy utilization of steam heating equipment. This standard applies to direct heating or indirect heating with steam power greater than or equal to 325kW or steam load greater than or equal to 0.5t/h. Hot steam equipment mainly includes cooking, evaporation and distillation, drying and comprehensive steam equipment. This standard does not apply to steam powered equipment.

2 Normative references

The following documents are indispensable for the application of this document. For dated reference documents, only the dated version applies to this article Pieces. For undated reference documents, the latest version (including all amendments) is applicable to this document.

GB/T 8222 General rules for electric energy balance of electrical equipment

GB 17167 General rules for the provision and management of energy measuring instruments for energy-consuming units

GB/T 30839.4 Energy consumption grading of industrial electric heating devices Part

3 Terms and definitions

The following terms and definitions defined in GB/T 8222 and GB/T 30839.4 apply to this document.

3.1 Feedliquid The liquid after mixing water and solution with medicine and materials.

3.2 Refluxliquidratio The ratio of the amount of reflux liquid to the amount of distillate in the distillation process.

3.3 Comprehensive steam equipment equipment for the whole steam heating process It is a large-scale steam equipment that uses steam as a heat source to complete the entire production process of cooking, washing, bleaching, etc. and drying.

3.4 Exhauststeam The secondary steam generated after steam is boiled or evaporated for more than one time, and the low enthalpy steam released by the equipment.

3.5 Overflowwater In the multi-tank rinsing process, the clean water is automatically discharged from the last tank and the reverse inverted tank (rinsing material) flows to the first tank, and flows continuously from the overflow of the first tank Out of the washing water.

3.6 Directheating The steam is in direct contact with the heated material to complete the heat exchange process.

3.7 Indirect heating The process of heat exchange between the steam and the heated material through the intermediate heating medium.

3.8 Thermal efficiency The ratio of effective use of heat to input heat.

3.9 Surface temperaturerise When the steam heating equipment reaches a thermally stable state, the difference between the temperature at any measurement point on the outside surface of the equipment and the ambient temperature.

4 Energy-saving monitoring and inspection

4.1 Monitoring and inspection of steam heating equipment should be carried out under normal conditions.

4.2 The steam heating equipment should be equipped with corresponding temperature monitoring instruments for drainage, exhaust steam, overflow water, exhaust and other parameters according to the monitoring needs.

4.3 The steam heating equipment under test should have complete technical documents such as instructions for use, operating accounts, and monitoring reports.

4.4 The online monitoring instrument is fully equipped and should meet the relevant requirements of GB 17167.

4.5 Steam heating equipment should have a thermal efficiency test report issued by a qualified professional organization.

6 Energy-saving monitoring and calculation methods

6.1 Hydrophobic temperature Open the bypass valve after the steam heating equipment trap (should be installed before monitoring), use a temperature meter to test every 20 minutes, whichever is The average value is the drainage temperature; where the steam runs straight, the monitoring is unqualified.

6.2 Exhaust steam temperature At 0.3m from the exhaust steam outlet of the last heat-absorbing surface of the steam heater, use a temperature meter to measure it every 20 minutes, and take the average value as the exhaust steam. Steam temperature.

6.3 Overflow water temperature At the overflow water outlet of the container, measure it every 20 minutes with a temperature meter, and take the average value as the overflow water temperature.

6.4 Exhaust temperature In the measuring hole within 0.3m of the exhaust of the drying equipment, a temperature meter is used to test every 20 minutes, and the average value is the exhaust temperature.

6.5 Surface temperature rise of equipment The measuring point of the temperature rise on the outer surface of the equipment should be representative. One measuring point is set at 1m2~1.5m2, and at least 3 measuring points are set. It is stable under thermal conditions. After the test, the outer surface temperature of each point measured by the temperature meter, and the maximum difference between it and the ambient temperature is the actual value of the monitoring.

6.6 Deviation of reflux ratio Use a flow meter to measure the average reflux qh and average distillate volume ql of the distillation column, and the measured reflux ratio is calculated according to formula (1). Rc= qh ql× 100% (1)

Appendix B

(Normative appendix) Calculation method for monitoring thermal efficiency of evaporation and distillation equipment B.1 Calculation of input heat The input heat Qr of evaporation and distillation should be calculated according to formula (B.1). Qr=D(hq-ha) GL(CLtL-CLta) (B.1) Where. Qr

---input heat of evaporation and distillation, in kilojoules (kJ); D

--- Steam consumption during the test period, in kilograms (kg); hq

--- The enthalpy value of steam under working pressure or working temperature, in kilojoules per kilogram (kJ/kg); ha

---The enthalpy value of water at ambient temperature ta, in kilojoules per kilogram (kJ/kg); GL

---the weight of the raw material liquid, in kilograms (kg); CL

---The specific heat capacity of the raw material liquid, in kilojoules per kilogram degrees Celsius [kJ/(kg·°C)]; tL

--- the temperature of the raw material liquid under working conditions, in degrees Celsius (°C); ta

--- Ambient temperature, in degrees Celsius (°C). B.2 Calculation of the specific heat capacity of the raw material liquid The raw material liquid specific heat capacity CL should be calculated according to formula (B.2). CL= CL1·phi0 CL2(100-phi0)/100 (B.2) Where. CL1

---The average specific heat capacity of the solute, in kilojoules per kilogram degrees Celsius [kJ/(kg·°C)]; CL2

---The average specific heat capacity of the solution, in kilojoules per kilogram degrees Celsius [kJ/(kg·°C)]; phi0

--- The weight percentage of solute, %. B.3 Calculation of effective heat of evaporation and distillation The effective heat of evaporation and distillation Qyx should be calculated according to formula (B.3). Qyx=Gy1(Cy1ty1-Cy1ta) Gy2(Cy2ty2-Cy2ta) Gy3(Cy3ty3-Cy3ta) Gy4(Cy4ty4-Cy4ta) (B.3) Where. Gy1

---the weight of the finished liquid (residual liquid), in kilograms (kg); Cy1

---The average specific heat capacity of the finished liquid (residual liquid), in kilojoules per kilogram degrees Celsius [kJ/(kg·°C)]; ty1

Appendix C

(Normative appendix) Thermal efficiency monitoring calculation method for drying or comprehensive steam equipment C.1 Calculation of input heat The heat input Qr of drying or comprehensive steam equipment should be calculated according to formula (C.1). Qr=QD QF (C.1) Where. QD

--- steam supply heat, in kilojoules (kJ); QF

--- The amount of heat generated by the chemical reaction of the material and the liquid medicine, in kilojoules (kJ). C.2 Calculation of steam supply heat The heat QD supplied by steam for drying or comprehensive steam-using equipment shall be calculated according to formula (C.2). QD=D(hq-ha) (C.2) Where. D

--- Steam consumption during the test period, in kilograms (kg); hq

--- The enthalpy value of steam under working pressure or working temperature, in kilojoules per kilogram (kJ/kg); ha

---The enthalpy of water at ambient temperature, in kilojoules per kilogram (kJ/kg). C.3 Calculation of the calorific value of the chemical reaction of the material liquid The calorific value QF of the chemical reaction of the material liquid chemical reaction should be calculated according to the formula (C.3). QF=B0Qwf (C.3) Where. B0

---The weight of the exothermic material, in kilograms (kg); Qwf

---the heat of the reaction material, in kilojoules per kilogram (kJ/kg). C.4 Calculation of effective heat of drying or comprehensive steam equipment The effective heat Qyx of drying or comprehensive steam equipment should be calculated according to formula (C.4). Qyx=Q4yx Q3yx Q2yx Q1yx (C.4) Where. Q4yx

---The heat absorption of the material and the liquid medicine containing the moisture infusion, the unit is kilojoules (kJ); Q3yx

---Material and water in the steamer heat up to absorb heat, the unit is kilojoules (kJ); Q2yx

---the heat absorption of the material and its water content during washing and rinsing in the flat washing tank, in kilojoules (kJ); Q1yx

---The heat absorption of heating and evaporating moisture when the material and its moisture are dried, the unit is kilojoule (kJ). The heat absorption heat Q4yx of the material and the chemical liquid containing the damp immersion liquid should be calculated according to the formula (C.5). Q4yx=Gh C1 100-eta0 100 Cs eta0 100 (t7-ta0) (C.5)