CN115061000A - Method for correcting power consumption of air feeder in calculation of power consumption of unit thermal power plant - Google Patents

Abstract

The invention discloses a method for correcting the power consumption of a blower in the power consumption calculation of a thermal power plant of a unit, which comprises the following steps: a. calculating a correction factor f of the atmospheric temperature to the power consumption of the blower according to the experimental atmospheric temperature and the design atmospheric temperature ₁ (ii) a b. Calculating a correction factor f of the specific air flow to the power consumption of the blower according to the coal quality and the actually measured excess air coefficient ₂ (ii) a c. Calculating a correction factor f of boiler input heat to blower power consumption according to the actually measured boiler efficiency and coal calorific value ₃ (ii) a d. According to the exhaust steam pressure of the steam turbine, calculating a correction factor f of the exhaust steam pressure to the power consumption of the blower ₄ (ii) a f. According to the number of ageing months of the steam turbine, calculating the ageing pair blower of the steam turbineCorrection factor f for power consumption ₅ (ii) a g. Calculating the power consumption of the corrected air blower by using each correction factor and the actually measured power consumption; h. each correction factor is selected according to the purpose of the test. The invention is used for correcting the power consumption of the air feeder, and the corrected power consumption can reflect the real performance of equipment and units under the corresponding test purpose.

Description

A method of correcting the power consumption of the blower in the calculation of the power consumption rate of the thermal power unit of the unit

technical field

The invention belongs to the field of thermal performance testing of generator sets, and in particular relates to a method for correcting the power consumption of a blower in the calculation of the power consumption rate of a thermal power set plant.

Background technique

Plant power consumption is an index reflecting the power consumption of auxiliary equipment of the unit. In addition to its own performance, the factors affecting the plant power consumption of the unit mainly include: (1) External conditions, such as changes in coal types, changes in ambient temperature, etc. When the conditions deviate from the design value, it will have a greater impact on the energy consumption of equipment such as blowers, fans and feed pumps; (2) Operating conditions, such as operating mode and operating parameter settings that deviate from the design (or guaranteed) operating conditions requirements, will also It affects the energy consumption indicators of auxiliary equipment to varying degrees.

Among all the electrical equipment in the plant, the factors that affect the measured power consumption of the blower are relatively complex, and the main influencing factors and influence rules are as follows:

(1) Atmospheric temperature. When the atmospheric temperature increases, the atmospheric density will decrease, output the same quality air, and the power consumption of the blower will increase accordingly;

(2) The air volume of the blower. The air volume of the blower is affected by the coal quality and the excess air coefficient of the boiler combustion. The specific air flow can be used to evaluate the theoretical air volume of the blower. When the specific air flow increases, the power consumption of the blower will increase accordingly;

(3) Boiler input heat. When the input heat of the boiler increases due to the increase of boiler efficiency or the increase of coal calorific value, the amount of coal required by the boiler to output the same heat decreases, the air volume of the blower decreases, and the power consumption of the blower decreases accordingly;

(4) Steam turbine exhaust pressure. When the exhaust steam pressure of the steam turbine increases with the change of the environmental conditions, and the output power of the unit is constant, the output heat of the boiler will increase significantly, so the amount of coal required will also increase, the air volume of the blower will increase, and the power consumption of the blower will increase accordingly. Increase;

(5) The performance of the steam turbine is aging. According to the objective law, the heat consumption rate of steam turbine increases gradually with the increase of operating time, which is called the performance aging of steam turbine. As the running time increases, under the condition of a certain output power of the unit, due to the continuous aging of the steam turbine performance, the output heat of the boiler will gradually increase, so the amount of coal required will also increase due to the aging of the steam turbine, and the primary air volume for conveying pulverized coal will increase. , the power consumption of the blower will increase accordingly.

Based on the above analysis, it is very important to correct the above influencing factors when evaluating the power consumption of the blower. However, there is no calculation formula or calculation method that fully considers the correction of the above factors in the published literature. Therefore, it is of great significance to discuss the correction calculation method of the power consumption of the blower in the calculation of the power consumption of the plant.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a method for correcting the power consumption of the blower in the calculation of the power consumption rate of the thermal power unit plant. Corrected to the corresponding design conditions.

To achieve the above object, the present invention adopts the following technical solutions to realize:

A method for correcting the power consumption of a blower in the calculation of the power consumption rate of a thermal power plant of a unit, using formula (1) to calculate the power consumption of the blower after the correction:

P _{FDF_corr} = P _{FDF_m} +ΔP _FDF (1)

In the formula: P _{FDF_corr} is the corrected power consumption of the blower, kW; P _{FDF_m} is the measured power consumption of the blower, kW; ΔP _FDF is the correction of the power consumption of the blower, kW;

The blower power consumption correction ΔP _FDF in formula (1) is calculated using formula (2):

ΔP _FDF =P _{FDF_m} ×f ₁ ×f ₂ ×f ₃ ×f ₄ ×f ₅ ×f ₆ -P _{FDF_m} (2)

In the formula: ΔP _FDF is the correction value of the power consumption of the blower, kW; P _{FDF_m} is the measured value of the power consumption of the blower, kW; f ₁ is the correction factor of the atmospheric temperature to the power consumption of the blower; f ₂ is the correction factor of the fan flow to the power consumption of the blower ; _f3 is the correction factor of the input heat of the boiler to the power consumption of the blower; _f4 is the correction factor of the exhaust steam pressure of the steam turbine to the power consumption of the blower; f5 is the correction factor of the performance aging of the steam turbine to the power consumption of the blower _{; f6} is other influences on the blower Correction factor for power consumption;

The correction factor f ₁ of the air temperature in the above formula (2) to the power consumption of the blower is calculated by formula (3):

In the formula: T _ref is the absolute boiler design atmospheric reference temperature, K; T _t is the absolute test atmospheric temperature, K; t _ref is the boiler design atmospheric reference temperature, °C; t _t is the test atmospheric temperature, °C;

The correction factor f ₂ of the blower flow in the formula (2) to the power consumption of the blower is calculated using the formula (4):

In the formula: Sa _d is the air preheater outlet specific air flow based on the design coal and the measured excess air coefficient, kg/kJ; Sat _is the air preheater outlet specific air flow based on the experimental coal and the measured excess air coefficient. , kg/kJ; among them, _Sad and _Sat are calculated with reference to the standard ASME PTC 4.

A further improvement of the present invention is that the correction factor f ₃ of the input heat of the boiler in the formula (2) to the power consumption of the blower is calculated using the formula (5):

Where: LHV _t is the low-level calorific value of the test coal, kJ/kg; LHV _d is the low-level calorific value of the design coal, kJ/kg; η _{b_t} is the measured boiler efficiency, %; η _{b_d} is the design boiler efficiency, %.

A further improvement of the present invention is that the correction factor _f4 of the steam turbine exhaust pressure in the formula (2) to the power consumption of the blower is calculated by using the formula (6):

In the formula: P _{b_t} is the measured steam turbine exhaust pressure, kPa; P _{b_d} is the design steam turbine exhaust pressure, kPa; k is the influence coefficient of the steam turbine exhaust pressure on the heat consumption rate of the steam turbine, %/kPa.

A further improvement of the present invention is that the influence coefficient k of the exhaust steam pressure of the steam turbine on the heat consumption rate of the steam turbine in the formula (6) is obtained from the correction curve of the back pressure to the heat consumption rate provided by the steam turbine manufacturer, or is obtained by changing the steam turbine. The back pressure characteristic test is obtained.

A further improvement of the present invention is that the correction factor f ₅ of the steam turbine performance aging in the formula (2) to the power consumption of the blower is calculated using the formula (7):

In the formula: M is the number of operating months from the first steam intake to the test, in months; B is the designed output power of the steam turbine, in MW; C is the rated main steam pressure, in MPa.

A further improvement of the present invention is that the correction item f ₁ involved in the formula (2) is a necessary correction item, and f ₂ , f ₃ , f ₄ , and f ₅ are selected according to different test purposes.

The further improvement of the present invention is that (a) if it is a performance acceptance test after the unit is put into operation to obtain the performance index of the unit that can be compared with the design guarantee value, all f ₂ to f ₅ need to be corrected; (b) if it is to obtain For the performance test of the unit under the current actual performance index under the design coal quality of the unit, f ₂ , f ₃ , and f ₄ are corrected, f ₅ =1; (c) If it is to obtain the actual performance index under the current coal quality of the unit operation For the performance test of the unit, f ₁ and f ₄ are corrected, f ₂ =1, f ₃ =1, f ₅ =1; (d) If the performance is to obtain the performance index of the blower equipment under the design conditions Test, f ₁ ~ f ₅ need to be revised.

A further improvement of the present invention is that the boiler design atmospheric reference temperature t _ref in formula (3) is obtained from the "Boiler Thermal Calculation Book" provided by the boiler manufacturer.

The present invention at least has the following beneficial technical effects:

In the test calculation of power consumption of thermal power plant, this method is used to provide a correction calculation method to adjust the six factors (atmospheric temperature, fan air volume, measured boiler efficiency, coal low calorific value, steam turbine) that affect the power consumption of the blower according to different test purposes. Exhaust pressure, steam turbine aging) are corrected to the design values, so that the power consumption of the blower and the power consumption of the plant can reflect the real performance of the unit and equipment under the corresponding test purpose.

Description of drawings

Fig. 1 is a typical steam turbine heat consumption rate and steam turbine exhaust pressure relationship curve.

Detailed ways

The method for correcting the power consumption of the blower in the calculation of the power consumption rate of a thermal power generating unit of the present invention will be further described in detail below with reference to an example.

The invention provides a method for correcting the power consumption of a blower in the calculation of the power consumption rate of a thermal power unit plant, comprising the following steps:

Use formula (1) to calculate the corrected power consumption of the blower:

P _{FDF_corr} = P _{FDF_m} +ΔP _FDF (1)

Where: P _{FDF_corr} is the corrected power consumption of the blower, kW; P _{FDF_m} is the measured power consumption of the blower, kW; ΔP _FDF is the correction of the power consumption of the blower, kW.

The blower power consumption correction ΔP _FDF in formula (1) is calculated using formula (2):

ΔP _FDF =P _{FDF_m} ×f ₁ ×f ₂ ×f ₃ ×f ₄ ×f ₅ ×f ₆ -P _{FDF_m} (2)

In the formula: ΔP _FDF is the correction value of the power consumption of the blower, kW; P _{FDF_m} is the measured value of the power consumption of the blower, kW; f ₁ is the correction factor of the atmospheric temperature to the power consumption of the blower; f ₂ is the correction factor of the fan flow to the power consumption of the blower ; _f3 is the correction factor of the input heat of the boiler to the power consumption of the blower; _f4 is the correction factor of the exhaust steam pressure of the steam turbine to the power consumption of the blower; f5 is the correction factor of the performance aging of the steam turbine to the power consumption of the blower _{; f6} is other influences on the blower Correction factor for power consumption.

The correction factor f ₁ of the air temperature in the above formula (2) to the power consumption of the blower is calculated by formula (3):

In the formula: T _ref is the absolute boiler design atmospheric reference temperature, K; T _t is the absolute test atmospheric temperature, K; t _ref is the boiler design atmospheric reference temperature, °C; t _t is the test atmospheric temperature, °C.

The boiler design atmospheric reference temperature t _ref in formula (3) is obtained from the "Boiler Thermal Calculation Book" provided by the boiler manufacturer.

The correction factor f ₂ of the blower flow in the formula (2) to the power consumption of the blower is calculated using the formula (4):

In the formula: Sa _d is the air preheater outlet specific air flow based on the design coal and the measured excess air coefficient, kg/kJ; Sat _is the air preheater outlet specific air flow based on the experimental coal and the measured excess air coefficient. , kg/kJ. Among them, _Sad and _Sat are calculated with reference to the standard ASME PTC 4.

The correction factor f ₃ of the input heat of the boiler in the formula (2) to the power consumption of the blower is calculated using the formula (5):

Where: LHV _t is the low-level calorific value of the test coal, kJ/kg; LHV _d is the low-level calorific value of the design coal, kJ/kg; η _{b_t} is the measured boiler efficiency, %; η _{b_d} is the design boiler efficiency, %.

The correction factor _f4 of the steam turbine exhaust pressure in the formula (2) to the power consumption of the blower is calculated using the formula (6):

In the formula: P _{b_t} is the measured steam turbine exhaust pressure, kPa; P _{b_d} is the design steam turbine exhaust pressure, kPa; k is the influence coefficient of the steam turbine exhaust pressure on the heat consumption rate of the steam turbine, %/kPa.

The influence coefficient k of the exhaust steam pressure of the steam turbine on the heat consumption rate of the steam turbine in the formula (6) is obtained from the correction curve of the back pressure to the heat consumption rate provided by the steam turbine manufacturer as shown in Fig. The back pressure characteristic test is obtained.

The correction factor f5 of the steam turbine performance aging to the power consumption of the blower in formula ( ₂ ) is calculated by formula (7):

In the formula: M is the number of operating months from the first steam intake to the test, in months; B is the designed output power of the steam turbine, in MW; C is the rated main steam pressure, in MPa.

The correction item f ₁ involved in formula (2) is a necessary correction item, and f ₂ , f ₃ , f ₄ , and f ₅ can be appropriately selected according to different test purposes: (a) If it is to obtain a value that can be compared with the design guarantee The performance acceptance test after the unit is put into operation based on the performance indicators of the unit (net heat consumption rate, net output power, coal consumption for power supply, plant power consumption, plant power consumption index), f ₂ ~ f ₅ need to be revised; (b) If yes The unit performance test to obtain the current actual performance indicators (net heat consumption rate, net output power, coal consumption for power supply, plant power, plant power consumption) under the design coal quality of the unit, f ₂ (without correction for boiler efficiency) , f ₃ , f ₄ are corrected, f ₅ =1; (c) If it is to obtain the actual performance indicators (net heat consumption rate, net output power, power supply coal consumption, plant power, plant power consumption), f ₁ , f ₄ are corrected, f ₂ =1, f ₃ =1, f ₅ =1; (d) If it is to obtain the performance index of the blower equipment under the design conditions ( For the performance test conducted based on the power consumption of the blower), f ₁ to f ₅ need to be corrected.

The calculation method of the correction factor f6 involved in the _formula (2), which affects the power consumption of the blower, is determined through negotiation between all parties involved in the test according to the special circumstances of the actual operation of the unit. In the above three test purposes (a), (b) and (c), whether f ₆ needs to be corrected is determined by negotiation between all parties involved in the test according to the special circumstances of the actual operation of the unit.

Example description:

As shown in Table 1, the example is an overall performance acceptance test for a 660MW coal-fired thermal power unit. The power consumption of the unit needs to be corrected and calculated, so the power consumption of the blower needs to be corrected accordingly. The example belongs to the test purpose (a) in claim 10, so the correction factors f ₁ to f ₅ that affect the power consumption of the blower need to be corrected and calculated.

The test unit is equipped with a total of 2 blowers. Under the 100% TMCR test condition, the operation mode of the blowers is to run all 2 blowers. During the test, the output power of the generator set was 686.380MW, the total power consumption of the auxiliary power was 56950.7kW, and the total power consumption of the two blowers was 1936.2kW.

In this example, the calculation results show that by correcting the atmospheric temperature, the air volume of the blower, the measured boiler efficiency, the low calorific value of coal, the exhaust pressure of the steam turbine, and the aging of the steam turbine to the design values, the corrected power consumption of the blower is 237.3kW. The power consumption is 2173.5kW, and the total plant power consumption after the correction of the power consumption of the blower is 57188.0kW.

Table 1 Example of power consumption correction calculation for blower

Although the present invention has been described in detail above with general description and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made on the basis of the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention fall within the scope of the claimed protection of the present invention.

Claims (8)

1. a method for correcting the power consumption of the blower in the calculation of the power consumption rate of the thermal power unit plant of the unit, it is characterized in that, adopt formula (1) to calculate the power consumption of the blower after the correction: P _{FDF_corr} = P _{FDF_m} +ΔP _FDF (1) In the formula: P _{FDF_corr} is the corrected power consumption of the blower, kW; P _{FDF_m} is the measured power consumption of the blower, kW; ΔP _FDF is the correction of the power consumption of the blower, kW; The blower power consumption correction ΔP _FDF in formula (1) is calculated using formula (2): ΔP _FDF =P _{FDF_m} ×f ₁ ×f ₂ ×f ₃ ×f ₄ ×f ₅ ×f ₆ -P _{FDF_m} (2) In the formula: ΔP _FDF is the correction value of the power consumption of the blower, kW; P _{FDF_m} is the measured value of the power consumption of the blower, kW; f ₁ is the correction factor of the atmospheric temperature to the power consumption of the blower; f ₂ is the correction factor of the fan flow to the power consumption of the blower ; _f3 is the correction factor of the input heat of the boiler to the power consumption of the blower; _f4 is the correction factor of the exhaust steam pressure of the steam turbine to the power consumption of the blower; f5 is the correction factor of the performance aging of the steam turbine to the power consumption of the blower _{; f6} is other influences on the blower Correction factor for power consumption; The correction factor f ₁ of the air temperature in the above formula (2) to the power consumption of the blower is calculated by formula (3):

In the formula: T _ref is the absolute boiler design atmospheric reference temperature, K; T _t is the absolute test atmospheric temperature, K; t _ref is the boiler design atmospheric reference temperature, °C; t _t is the test atmospheric temperature, °C; The correction factor f ₂ of the blower flow in the formula (2) to the power consumption of the blower is calculated using the formula (4):

In the formula: Sa _d is the air preheater outlet specific air flow based on the design coal and the measured excess air coefficient, kg/kJ; Sat _is the air preheater outlet specific air flow based on the experimental coal and the measured excess air coefficient. , kg/kJ; among them, _Sad and _Sat are calculated with reference to the standard ASME PTC 4. 2. the blower power consumption correction method in the calculation of the power consumption rate of a kind of unit thermal power unit plant as claimed in claim 1, it is characterized in that, the boiler input heat in formula (2) adopts the correction factor f ₃ of blower power consumption Formula (5) is calculated:

Where: LHV _t is the low-level calorific value of the test coal, kJ/kg; LHV _d is the low-level calorific value of the design coal, kJ/kg; η _{b_t} is the measured boiler efficiency, %; η _{b_d} is the design boiler efficiency, %. 3. the blower power consumption correction method in a kind of unit thermal power unit factory electricity consumption rate calculation as claimed in claim 1, it is characterized in that, the steam turbine exhaust pressure in formula ( ₂ ) is to the correction factor f of blower power consumption Use formula (6) to calculate:

In the formula: P _{b_t} is the measured steam turbine exhaust pressure, kPa; P _{b_d} is the design steam turbine exhaust pressure, kPa; k is the influence coefficient of the steam turbine exhaust pressure on the heat consumption rate of the steam turbine, %/kPa. 4. the blower power consumption correction method in a kind of unit thermal power unit factory electricity rate calculation as claimed in claim 3, it is characterized in that, the coefficient of influence k of the steam turbine exhaust pressure in the formula (6) to the steam turbine heat consumption rate It can be obtained from the back pressure versus heat consumption rate correction curve provided by the steam turbine manufacturer, or obtained by conducting the steam turbine variable back pressure characteristic test. 5. the method for correcting the power consumption of the blower in the calculation of the power consumption rate of a thermal power plant of a kind of unit as claimed in claim 1, it is characterized in that, the steam turbine performance aging in the formula (2) adopts the correction factor f ₅ of the power consumption of the blower. Formula (7) is used to calculate:

In the formula: M is the number of operating months from the first steam intake to the test, in months; B is the designed output power of the steam turbine, in MW; C is the rated main steam pressure, in MPa. 6. the blower power consumption correction method in a kind of unit thermal power unit factory electricity rate calculation as claimed in claim 1, it is characterized in that, the correction item f1 involved in _formula ( ₂ ) is a necessary correction item, f2, f ₃ , f ₄ , and f ₅ are selected according to the purpose of the test. 7. the blower power consumption correction method in a kind of unit thermal power unit factory electricity rate calculation as claimed in claim 6, it is characterized in that, (a) if it is to obtain the unit performance index that can be compared with design guarantee value and carry out For the performance acceptance test after the unit is put into operation, f ₂ to f ₅ need to be revised; (b) If it is a unit performance test to obtain the current actual performance index under the design coal quality of the unit, f ₂ , f ₃ and f ₄ shall be Correction, f ₅ =1; (c) If it is a unit performance test to obtain the actual performance index of the unit under the current coal quality of operation, f ₁ and f ₄ are corrected, f ₂ =1, f ₃ =1, f ₅ = 1; (d) If it is a performance test to obtain the performance index of the blower equipment under the design conditions, all f ₁ to f ₅ need to be corrected. 8. the blower power consumption correction method in a kind of unit thermal power unit factory electricity rate calculation as claimed in claim 1, it is characterized in that, the boiler design atmospheric reference temperature t _ref in formula (3) provides from boiler factory Obtained from "Boiler Thermal Calculation Book".

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