CN211454603U - Low-pressure cylinder efficiency measuring and calculating system - Google Patents

Abstract

The utility model relates to a low pressure cylinder efficiency measuring and calculating system, which comprises a boiler, a generator, a condenser, a heat recovery system, a water feeding pump turbine, a condensate pump, a deaerator, a shaft seal heater, a high pressure cylinder, a medium pressure cylinder and a low pressure cylinder; the heat regenerative system comprises a high-pressure heater system and a low-pressure heater system; and a drainage flow measuring device is arranged on a drainage pipeline of the low-pressure heater system, which is closest to the low-pressure heater, and is used for measuring the drainage flow from the last stage of low-pressure heater to the condenser and calculating the extraction enthalpy of the last stage of low-pressure heater. The utility model discloses based on the hydrophobic flow measurement final stage adds the extraction enthalpy, need not to confirm to be in the low enthalpy value that adds the section extraction in wet steam district through iterative mode, the calculation work load that has significantly reduced is guaranteeing that the final stage adds under the prerequisite of hydrophobic flow measurement precision, has improved the calculation accuracy and the speed of low pressure jar effectively.

Description

Low-pressure cylinder efficiency measuring and calculating system

Technical Field

The utility model belongs to the technical field of thermal power, especially, relate to a low pressure jar efficiency system of calculating.

Background

The real-time control of the low-pressure cylinder efficiency of the unit is important for monitoring the economical efficiency and safety of the unit operation. Whether the low-pressure cylinder efficiency is a pure condensing unit or a heat supply unit, whether the low-pressure cylinder efficiency is a new unit production performance acceptance test or an old unit through-flow modification and other important technical improvement examination tests, the low-pressure cylinder efficiency is determined through strict and complex performance tests with the highest test precision grade. The calculation accuracy requirement of the low-pressure cylinder efficiency is extremely high, the calculation result of the low-pressure cylinder efficiency directly influences the state level of the whole unit, is also a main basis for the project party to carry out expense settlement, and is focused by the test participating parties.

At present, in order to accurately measure and calculate the efficiency of a low-pressure cylinder of a steam turbine, a high-precision performance test is required, the adopted test standard is generally an international standard ASME PTC6-2004 or a national standard GB8117.1-2008, and the part 1 of the thermal performance test procedure of the steam turbine is as follows: method A-high accuracy test of large condensing steam turbine. The test uncertainty of the thermal power generating unit is relatively small, and is respectively 0.25% and 0.3% for the thermal power generating unit, but the test cost for the thermal power generating unit is high. As an industrial test, the cost problem should be considered on the premise of meeting the requirement of test precision.

The most difficult point of the existing calculation method for calculating the efficiency of the low-pressure cylinder is the determination of the steam enthalpy of the last stage or the last two stages and the exhaust enthalpy of the steam turbine. For a condensing unit, the last stage of extraction steam of the low-pressure cylinder and the exhaust steam of the low-pressure cylinder are often wet steam, and the enthalpy value of the low-pressure cylinder cannot be determined by measuring the steam pressure and the temperature. Because the steam humidity measurement accuracy of a large steam turbine is not high, the final-stage extraction and exhaust enthalpy are determined by the conventional calculation method in a multiple iteration mode. However, the whole iteration process is very complicated, and the parameters involved in the calculation process are very many, mainly including all steam-water flows and parameters of the unit and all auxiliary steam flows and parameters, and the measurement workload of the parameters is very huge, and the measurement accuracy is difficult to guarantee at the same time.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a low pressure cylinder efficiency system of calculating through installing hydrophobic flow measuring device on the drain pipe that is closest to low pressure feed water heater, measures the hydrophobic flow of last first order low pressure feed water heater to condenser, calculates last low pressure feed water heater extraction enthalpy based on measured hydrophobic flow to solve above-mentioned technical problem.

The utility model provides a low pressure cylinder efficiency measuring and calculating system, which comprises a boiler, a generator, a condenser, a regenerative system, a water feeding pump turbine, a condensate pump, a deaerator, a shaft seal heater, a high pressure cylinder, a medium pressure cylinder and a low pressure cylinder; the heat regenerative system comprises a high-pressure heater system and a low-pressure heater system; a drain flow measuring device is arranged on a drain pipeline of the low-pressure heater system, which is closest to the low-pressure heater, and is used for measuring the drain flow from the last stage low-pressure heater to a condenser and calculating the extraction enthalpy of the last stage low-pressure heater;

the low-pressure heater system comprises a first low-pressure heater, a second low-pressure heater, a third low-pressure heater and a fourth low-pressure heater, the deaerator, the first low-pressure heater, the second low-pressure heater, the third low-pressure heater, the fourth low-pressure heater, the shaft seal heater and the condenser are sequentially connected, and the drainage flow measuring device is arranged on a drainage pipeline between the fourth low-pressure heater and the condenser;

and a condensate flow measuring device is arranged on a pipeline between the deaerator and the first low-pressure heater and used for measuring the condensate flow of the first low-pressure heater entering the deaerator.

By means of the scheme, the low-pressure cylinder efficiency measuring and calculating system is used for measuring the drain flow rate of the last-stage low-pressure heater to the condenser by installing the drain flow measuring device on the drain pipeline closest to the low-pressure heater, the drain flow from the last-stage low-pressure heater to the condenser is calculated based on the measured drain flow, the enthalpy value of the low-pressure steam extraction section in the wet steam area can be determined without an iteration mode, the calculation workload is greatly reduced, and the calculation precision and the speed of the low-pressure cylinder are effectively improved on the premise that the flow measurement precision of the last-stage low-pressure steam extraction section is guaranteed.

The above description is only an overview of the technical solution of the present invention, and in order to make the technical means of the present invention clearer and can be implemented according to the content of the description, the following detailed description is made with reference to the preferred embodiments of the present invention and accompanying drawings.

Drawings

Fig. 1 is a schematic structural diagram of the low-pressure cylinder efficiency measuring and calculating system of the present invention.

Reference numbers in the figures:

1 is 1 # Gaojia; 2 is No. 2 Gaojia; 3 is No. 3 Gaojia; 4 is a deaerator; 5 is No. 5 low addition; no. 6 is No. 6 low addition; 7 is No. 7 low plus; 8 is No. 8 low addition; 9 is a high-pressure cylinder; 10 is a middle pressure cylinder; 11 is a low-pressure cylinder; 12 is a boiler; 13 is a generator; 14 is a condenser; 15 is a condensate pump; 16 is a shaft seal heater; 17 is a hydrophobic flow measuring device; 18 is a condensate flow measuring device; 19 is a feed pump turbine.

Detailed Description

The following detailed description of the embodiments of the present invention is provided with reference to the accompanying drawings and examples. The following examples are intended to illustrate the invention, but are not intended to limit the scope of the invention.

Referring to fig. 1, the present embodiment provides a low pressure cylinder efficiency measuring and calculating system, which includes a boiler 12, a generator 13, a condenser 14, a regenerative system, a feed pump turbine 19, a condensate pump 15, a deaerator 4, a shaft seal heater 16, a high pressure cylinder 9, an intermediate pressure cylinder 10, and a low pressure cylinder 11; the heat regenerative system comprises a high-pressure heater system and a low-pressure heater system; a drainage flow measuring device is arranged on a drainage pipeline of the low-pressure heater system, which is closest to the low-pressure heater, and is used for measuring the drainage flow from the last stage low-pressure heater to a condenser and calculating the extraction enthalpy of the last stage low-pressure heater; the low-pressure heater system comprises a first low-pressure heater (No. 5 low plus 5), a second low-pressure heater (No. 6 low plus 6), a third low-pressure heater (No. 7 low plus 7) and a fourth low-pressure heater (No. 8 low plus 8), a deaerator 4, the first low-pressure heater, the second low-pressure heater, the third low-pressure heater, the fourth low-pressure heater, a shaft seal heater 16 and a condenser 14 are sequentially connected, and a drainage flow measuring device 17 is arranged on a drainage pipeline between the fourth low-pressure heater and the condenser 14; and a condensate flow measuring device 18 is arranged on a pipeline between the deaerator 4 and the first low-pressure heater and used for measuring the condensate flow of the first low-pressure heater entering the deaerator 4.

In the embodiment, the hydrophobic flow measuring device 17 is installed on a section of straight pipe section between the No. 8 low-pressure steam trap and the condenser, the No. 8 low-pressure steam inlet flow can be obtained by measuring the flow and combining with the 5-7 low-pressure heat balance calculation, and then the enthalpy value of the No. 8 low-pressure steam extraction can be determined through the energy balance, namely the enthalpy value of the No. 8 low-pressure steam extraction in the wet steam area can be determined without an iteration mode.

The water side condensate flow of the low-pressure heater is measured by a condensate flow measuring device 16 which is arranged between the No. 5 low-pressure heater and the deaerator, and the steam inlet flow of the No. 5-7 low-pressure heater can be calculated based on the condensate flow and the steam side and water side parameters of the heater.

The end point enthalpy (ELEP) of the expansion line entering the condenser exhaust steam can be determined based on the continuous expansion line and the exhaust steam pressure between the steam entering the intermediate pressure cylinder and the No. 8 low pressure steam extraction section.

The low pressure cylinder exhaust enthalpy, i.e., useful energy end enthalpy (UEEP), may be determined based on the expansion line end enthalpy, exhaust dryness, and exhaust loss.

Through the measuring and calculating system of the embodiment, when the low-pressure cylinder efficiency is measured and calculated, complex iteration about the final-stage low-pressure steam extraction enthalpy and the low-pressure cylinder steam exhaust enthalpy is not needed, and the calculation workload is greatly reduced. Meanwhile, the balance calculation of input energy and output energy of the whole machine is not needed in the calculation process, so that steam-water parameters required by calculation are greatly reduced, the calculation deviation of the low-pressure cylinder efficiency caused by individual measurement errors is effectively avoided, and the calculation accuracy and speed of the low-pressure cylinder are effectively improved on the premise of ensuring the measurement accuracy of the final-stage low-plus-hydrophobic flow.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and it should be noted that, for those skilled in the art, a plurality of modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.

Claims (1)

1. The low-pressure cylinder efficiency measuring and calculating system is characterized by comprising a boiler, a generator, a condenser, a heat recovery system, a water feeding pump turbine, a condensate pump, a deaerator, a shaft seal heater, a high-pressure cylinder, a medium-pressure cylinder and a low-pressure cylinder; the heat regenerative system comprises a high-pressure heater system and a low-pressure heater system; a drain flow measuring device is arranged on a drain pipeline of the low-pressure heater system, which is closest to the low-pressure heater, and is used for measuring the drain flow from the last stage low-pressure heater to a condenser and calculating the extraction enthalpy of the last stage low-pressure heater;

the low-pressure heater system comprises a first low-pressure heater, a second low-pressure heater, a third low-pressure heater and a fourth low-pressure heater, the deaerator, the first low-pressure heater, the second low-pressure heater, the third low-pressure heater, the fourth low-pressure heater, the shaft seal heater and the condenser are sequentially connected, and the drainage flow measuring device is arranged on a drainage pipeline between the fourth low-pressure heater and the condenser;

and a condensate flow measuring device is arranged on a pipeline between the deaerator and the first low-pressure heater and used for measuring the condensate flow of the first low-pressure heater entering the deaerator.

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