阅读说明：本技术 一种背压对汽轮发电机组及其出力空间影响的分析方法 (Method for analyzing influence of back pressure on steam turbine generator unit and output space of steam turbine generator unit ) 是由 郑威 朱本国 李丽 祝令凯 郭俊山 韩悦 于 2019-09-30 设计创作，主要内容包括：本发明公开了一种背压对汽轮发电机组及其出力空间影响的分析方法,汽轮发电机组包括锅炉、汽轮机、发电机凝汽器、凝泵、低压加热器、除氧器、给水泵、高压加热器、过热器和再热器等设备。分析方法采用以下步骤：测试机组的最大出力以及最大主蒸汽流量；根据机组设计最大连续出力工况和铭牌工况热平衡图,计算出背压对出力的影响系数；计算出汽轮发电机组在最大主蒸汽流量下的背压；计算出汽轮发电机组在当前工况下的最大出力；比较计算最大出力和汽轮发电机组当前工况下出力,计算机组剩余出力空间。本发明保证机组既能安全稳定运行,又能发挥出力能力,最大限度地减少了拉闸限电对人民生活的影响。(The invention discloses an analysis method for influence of backpressure on a turbo generator set and an output space of the turbo generator set. The analysis method comprises the following steps: testing the maximum output of the unit and the maximum main steam flow; calculating the influence coefficient of the back pressure on the output according to the maximum continuous output working condition and the nameplate working condition thermal balance diagram designed by the unit; calculating the back pressure of the steam turbine generator unit under the maximum main steam flow; calculating the maximum output of the steam turbine generator unit under the current working condition; and comparing and calculating the maximum output and the output of the turbo generator set under the current working condition, and calculating the residual output space of the turbo generator set. The invention ensures that the unit can run safely and stably, can exert the output capacity and furthest reduces the influence of the brake-out electricity-limiting on the life of people.)

1. The utility model provides a backpressure is to turbo generator set, is including boiler, steam turbine and the generator that connects gradually, characterized by still includes over heater, high pressure feed water heater and reheater, the steam turbine has high pressure jar, intermediate pressure jar and low pressure jar, high pressure jar, intermediate pressure jar and low pressure jar through pivot and generator rigid connection, the boiler receives to provide main steam for the high pressure jar after the desuperheating water of over heater and high pressure feed water heater, the boiler still receives the desuperheating water of reheater and the cold reheat steam of high pressure jar and provides reheat steam for the intermediate pressure jar, the steam extraction mouth of high pressure jar, intermediate pressure jar and low pressure jar can supply vapour externally.

2. The back pressure steam turbine generator unit as claimed in claim 1, further comprising an exhaust heat recovery device, wherein the exhaust heat recovery device comprises a condenser, a condensate pump, a low pressure heater, a deaerator and a water feed pump, a steam inlet of the condenser is connected with a steam outlet of the low pressure cylinder, and condensate of the condenser flows into the high pressure heater after passing through the condensate pump, the low pressure heater, the deaerator and the water feed pump in sequence.

3. A method for analyzing the influence of backpressure on the output space of a steam turbine generator unit is characterized by comprising the following steps:

step 1, testing the continuous and stable maximum output P of the turbo-generator unit under the conditions of pure condensation, 11.8kPa of back pressure and rated power factor_maxAnd maximum main steam flow G_max；

Step 2, calculating an influence coefficient K of back pressure on output according to a thermal balance diagram of a maximum continuous output working condition and a nameplate working condition of the design of the turbo generator set;

step 3, according to the back pressure p of the turbo generator set under the current working condition_bpcAnd main steam flow G_cCalculating the maximum main steam flow G of the steam turbine generator unit_maxBack pressure p of_bpcc；

Step 4, according to the tested maximum output P_maxAnd maximum main steam flow G_maxCalculating the back pressure p of the turbo-generator set_bpccMaximum force P_maxc；

Step 5, comparing the maximum output P_maxcAnd the output P of the steam turbine generator unit under the current working condition_c。

4. The method for analyzing the influence of the back pressure on the space of the output of the steam turbine generator unit as claimed in claim 3, wherein the influence coefficient K of the back pressure on the output is calculated by the following formula:

in the formula, P_TMCRdThe design output of the steam turbine generator unit under the TMCR working condition is provided; p_TRLdThe design output of the turbo generator set under the TRL working condition is provided; p is a radical of_bpTRLdDesigning back pressure for the turbo generator set under the TRL working condition; p is a radical of_bpTMCRdThe design backpressure of the steam turbine generator unit under the TMCR working condition is realized.

5. The method of claim 4The method for analyzing the influence of the back pressure on the output space of the steam turbine generator unit is characterized in that the back pressure p_bpccThe calculation formula of (2) is as follows:

in the formula, G_maxThe maximum main steam flow p of the turbo-generator set is continuous and stable under pure condensation, back pressure of 11.8kPa and rated power factor_bpcThe back pressure of the turbo generator set under the current working condition.

6. The method of claim 4, wherein the back pressure p of the steam turbine generator unit is used for analyzing the influence of the back pressure on the space of the steam turbine generator unit output_bpccMaximum force P_maxcThe calculation process of (2) is as follows:

when the steam turbine generator unit does not supply steam to the outside:

P_maxc＝P_max[1+(11.8-p_bpcc)K]

when the steam turbine generator unit has external steam supply and the steam extraction port is before cold re-cooling or cold re-cooling:

P_maxc＝P_max[1+(11.8-p_bpcc)K]-G_g(h_g+h_hrh-h_crh-h_ex)/3600

when the steam turbine generator unit has external steam supply and the steam extraction port is after cold again:

P_maxc＝P_max[1+(11.8-p_bpcc)K]-G_g(h_g-h_ex)/3600

in the formula, G_qThe steam supply flow is external; h is_gIs the enthalpy of externally supplied steam; h is_hrhIs the reheat steam enthalpy; h is_crhIs the cold reheat steam enthalpy; h is_exIs the exhaust enthalpy of the low pressure cylinder.

7. The method of claim 4, wherein the comparison P is a comparison of the spatial effect of backpressure on the output of the steam turbine generator unit_maxcAnd turbo generator units currentlyOutput P under working condition_cThe process comprises the following steps:

when P is present_maxc≥P_cWhen the residual output space of the steam turbine generator unit is P ═ P_maxc-P_c；

When P is present_maxc＜P_cAnd meanwhile, the residual output space of the steam turbine generator unit is P equal to 0.

Technical Field

The invention relates to an analysis method for influences of back pressure on a steam turbine generator unit and an output space of the steam turbine generator unit, and belongs to the technical field of power generation equipment.

Background

With the improvement of the living standard of people, the utilization rate of household air conditioners is greatly increased, the power load of a certain power saving network in 2018 is up to 7700 ten thousand kilowatts, wherein the air conditioner load is about 2500 ten thousand kilowatts, and the occupancy ratio is nearly 1/3. In 7 and 8 months every year, all thermal power generating units in the whole network need to make the most difficult preparation for meeting the peak and crossing summer, and for the provincial dispatching center, the output space of each unit also needs to be known at any time so as to reasonably arrange the generated energy of the units, thereby ensuring that the units can safely and stably operate and can exert the output capacity of the units.

In order to master the output capacity of the unit, according to the related requirements of 'notice of power-saving dispatching control center on network-related performance test management work of standard direct regulating unit', a new unit is subjected to a network coordination test before entering commercial operation or after the unit A is repaired (including other types of overhaul related to capacity-increasing transformation, control equipment and software upgrading and control logic and parameter modification), wherein one test item is high back pressure output, and the unit is tested under pure set, back pressure 11.8kPa and rated power factor to continuously and stably carry load capacity.

However, the maximum load of the unit under the high back pressure output test condition is grasped by the provincial dispatching center, and when the unit back pressure deviates from 11.8kPa or external steam supply exists, the output space of the unit is not clear.

Disclosure of Invention

Aiming at the defects of the method, the invention provides an analysis method for the influence of the back pressure on the steam turbine generator unit and the output space of the steam turbine generator unit, and the output space of the steam turbine generator unit when the back pressure deviates 11.8kPa can be calculated.

The technical scheme adopted for solving the technical problems is as follows:

on one hand, the back pressure pair steam turbine generator unit provided by the embodiment of the invention comprises a boiler, a steam turbine and a generator which are sequentially connected, and further comprises a superheater, a high-pressure heater and a reheater, wherein the steam turbine is provided with a high-pressure cylinder, an intermediate-pressure cylinder and a low-pressure cylinder, the high-pressure cylinder, the intermediate-pressure cylinder and the low-pressure cylinder are rigidly connected with the generator through rotating shafts, the boiler receives the desuperheating water of the superheater and the feed water of the high-pressure heater and then provides main steam for the high-pressure cylinder, the boiler also receives the desuperheating water of the reheater and the cold reheat steam of the high-pressure cylinder and provides reheat steam for the intermediate-pressure cylinder, and steam extraction ports of the high-.

As a possible implementation manner of this embodiment, this turbo generator set still includes exhaust waste heat recovery device, exhaust waste heat recovery device includes condenser, condensate pump, low pressure heater, oxygen-eliminating device and feed-water pump, the steam inlet of condenser is connected with the steam extraction mouth of low pressure jar, and the condensate of condenser flows into high pressure heater behind condensate pump, low pressure heater, oxygen-eliminating device and the feed-water pump in proper order.

On the other hand, the method for analyzing the influence of the backpressure on the output space of the steam turbine generator unit, provided by the embodiment of the invention, comprises the following steps:

step 1, testing the continuous and stable maximum output P of the turbo-generator unit under the conditions of pure condensation, 11.8kPa of back pressure and rated power factor_maxAnd maximum main steam flow G_max；

Step 2, calculating an influence coefficient K of the back pressure on the output according to a thermal balance diagram of a maximum continuous output working condition (TMCR) and a nameplate working condition (TRL) of the design of the steam turbine generator unit;

step 3, according to the back pressure p of the turbo generator set under the current working condition_bpcAnd main steam flow G_cCalculating the maximum main steam flow G of the steam turbine generator unit_maxBack pressure p of_bpcc；

Step 4, according to the tested maximum output P_maxAnd maximum main steam flow G_maxCalculating the back pressure p of the turbo-generator set_bpccMaximum force P_maxc；

Step 5, comparing the maximum output P_maxcAnd the output P of the steam turbine generator unit under the current working condition_c。

As a possible implementation manner of this embodiment, the calculation formula of the influence coefficient K of the back pressure on the output force is as follows:

in the formula, P_TMCRdThe design output of the steam turbine generator unit under the TMCR working condition is provided; p_TRLdThe design output of the turbo generator set under the TRL working condition is provided; p is a radical of_bpTRLdDesigning back pressure for the turbo generator set under the TRL working condition; p is a radical of_bpTMCRdThe design backpressure of the steam turbine generator unit under the TMCR working condition is realized.

As a possible implementation manner of this embodiment, the back pressure p_bpccThe calculation formula of (2) is as follows:

in the formula, G_maxThe maximum main steam flow p of the turbo-generator set is continuous and stable under pure condensation, back pressure of 11.8kPa and rated power factor_bpcThe back pressure of the turbo generator set under the current working condition.

As a possible implementation manner of this embodiment, the steam turbine generator unit is under the back pressure p_bpccMaximum force P_maxcThe calculation process of (2) is as follows:

when the steam turbine generator unit does not supply steam to the outside:

P_maxc＝P_max[1+(11.8-p_bpcc)K]

when the steam turbine generator unit has external steam supply and the steam extraction port is before cold re-cooling or cold re-cooling:

P_maxc＝P_max[1+(11.8-p_bpcc)K]-G_g(h_g+h_hrh-h_crh-h_ex)/3600

when the steam turbine generator unit has external steam supply and the steam extraction port is after cold again:

P_maxc＝P_max[1+(11.8-p_bpcc)K]-G_g(h_g-h_ex)/3600

in the formula, G_gThe steam supply flow is external; h is_gIs the enthalpy of externally supplied steam; h is_hrhIs the reheat steam enthalpy; h is_crhIs the cold reheat steam enthalpy; h is_exIs the exhaust enthalpy of the low pressure cylinder. h is_g、h_hrh、h_crhThe water and steam meter can be checked according to the corresponding pressure and temperature parameters of the steam turbine generator unit under the current working condition; h is_exCan be dependent on the pressure P_bpccAnd the dryness is 0.92, and the water and steam tables are checked to obtain the dryness.

As a possible implementation manner of this embodiment, the comparison P is_maxcAnd the output P of the steam turbine generator unit under the current working condition_cThe process comprises the following steps:

when P is present_maxc≥P_cWhen the residual output space of the steam turbine generator unit is P ═ P_maxc-P_c；

When P is present_maxc<P_cThen the turbo generator set remainsThe residual force space is P-0.

The technical scheme of the embodiment of the invention has the following beneficial effects:

the back pressure pair steam turbine generator unit comprises a boiler, a steam turbine and a generator which are connected in sequence, and further comprises a superheater, a high-pressure heater and a reheater, wherein the steam turbine is provided with a high-pressure cylinder, an intermediate-pressure cylinder and a low-pressure cylinder, the high-pressure cylinder, the intermediate-pressure cylinder and the low-pressure cylinder are rigidly connected with the generator through rotating shafts, the boiler receives temperature reduction water of the superheater and water supply of the high-pressure heater and then provides main steam for the high-pressure cylinder, the boiler also receives temperature reduction water of the reheater and cold reheat steam of the high-pressure cylinder and provides reheat steam for the intermediate-pressure cylinder, and steam extraction ports of the high-pressure cylinder, the intermediate-pressure cylinder and the low-pressure cylinder can supply. After the results are adopted, in summer at the peak of the attack, the dispatching department can know the output space of each unit at any time according to the analysis method disclosed by the invention so as to reasonably arrange the generated energy of the units, ensure that the units can safely and stably run, exert the output capacity and furthest reduce the influence of the pull-out brake power limiting on the life of people.

The method for analyzing the influence of the backpressure on the output space of the steam turbine generator unit mainly comprises the following steps of testing the maximum output and the maximum main steam flow of the unit under the specified conditions; calculating the influence coefficient of the back pressure on the output force; calculating the back pressure of the unit under the maximum main steam flow; calculating the maximum output of the unit under the current working condition; and calculating the maximum output and the current output by the comparison unit, and calculating the residual output space of the comparison unit. According to the result, the output space of each unit can be known at any time in summer at the peak-facing degree, so that the generated energy of the units can be reasonably arranged, the units can be ensured to safely and stably operate, the output capacity can be exerted, and the influence of brake-out electricity limiting on the life of people is reduced to the maximum extent.

Description of the drawings:

FIG. 1 is a schematic diagram illustrating a back pressure versus steam turbine generator set in accordance with an exemplary embodiment;

FIG. 2 is a flow chart illustrating a method for analyzing the effect of backpressure on a space of a steam turbine generator unit output according to an exemplary embodiment.

Detailed Description

The invention is further illustrated by the following examples in conjunction with the accompanying drawings:

in order to clearly explain the technical features of the present invention, the following detailed description of the present invention is provided with reference to the accompanying drawings. The following disclosure provides many different embodiments, or examples, for implementing different features of the invention. To simplify the disclosure of the present invention, the components and arrangements of specific examples are described below. Furthermore, the present invention may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. It should be noted that the components illustrated in the figures are not necessarily drawn to scale. Descriptions of well-known components and processing techniques and procedures are omitted so as to not unnecessarily limit the invention.

FIG. 1 is a schematic diagram illustrating a back pressure to steam turbine generator unit according to an exemplary embodiment. As shown in fig. 1, a back pressure-to-steam turbine generator set according to an embodiment of the present invention includes a boiler, a steam turbine, a generator, a superheater, a high pressure heater, and a reheater, which are sequentially connected to each other, where the steam turbine includes a high pressure cylinder, an intermediate pressure cylinder, and a low pressure cylinder, the high pressure cylinder, the intermediate pressure cylinder, and the low pressure cylinder are rigidly connected to the generator through a rotating shaft, the boiler receives desuperheating water of the superheater and feed water of the high pressure heater and then supplies main steam to the high pressure cylinder, the boiler further receives desuperheating water of the reheater and cold reheat steam of the high pressure cylinder and supplies reheat steam to the intermediate pressure cylinder, and steam extraction ports of the high pressure cylinder, the intermediate pressure cylinder, and the.

As a possible implementation manner of this embodiment, this turbo generator set still includes exhaust waste heat recovery device, exhaust waste heat recovery device includes condenser, condensate pump, low pressure heater, oxygen-eliminating device and feed-water pump, the steam inlet of condenser is connected with the steam extraction mouth of low pressure jar, and the condensate of condenser flows into high pressure heater behind condensate pump, low pressure heater, oxygen-eliminating device and the feed-water pump in proper order.

After the results are adopted, in summer at the peak of the attack, the dispatching department can know the output space of each unit at any time according to the analysis method disclosed by the invention so as to reasonably arrange the generated energy of the units, ensure that the units can safely and stably run, exert the output capacity and furthest reduce the influence of the pull-out brake power limiting on the life of people.

FIG. 2 is a flow chart illustrating a method for analyzing the effect of backpressure on a space of a steam turbine generator unit output according to an exemplary embodiment. As shown in fig. 2, an analysis method for analyzing an influence of back pressure on a space of a turbine generator unit according to an embodiment of the present invention includes the following steps:

step 1, testing the continuous and stable maximum output P of the turbo-generator unit under the conditions of pure condensation, 11.8kPa of back pressure and rated power factor_maxAnd maximum main steam flow G_max。

Step 2, calculating an influence coefficient K of the back pressure on the output according to the following formula according to a thermal balance diagram of a designed maximum continuous output working condition (TMCR) and a designed nameplate working condition (TRL) of the steam turbine generator unit:

in the formula, P_TMCRdThe design output of the steam turbine generator unit under the TMCR working condition is provided; p_TRLdThe design output of the turbo generator set under the TRL working condition is provided; p is a radical of_bpTRLdDesigning back pressure for the turbo generator set under the TRL working condition; p is a radical of_bpTMCRdThe design backpressure of the steam turbine generator unit under the TMCR working condition is realized.

Step 3, according to the back pressure p of the turbo generator set under the current working condition_bpcAnd main steam flow G_cCalculating the maximum main steam flow G of the steam turbine generator unit according to the following formula_maxBack pressure p of_bpcc：

In the formula, G_maxThe maximum main steam flow p of the turbo-generator set is continuous and stable under pure condensation, back pressure of 11.8kPa and rated power factor_bpcThe back pressure of the turbo generator set under the current working condition.

Step 4, according to the tested maximum output P_maxAnd maximum main steam flow G_maxCalculating the back pressure p of the turbo-generator set_bpccMaximum force P_maxc：

When the steam turbine generator unit does not supply steam to the outside:

P_maxc＝P_max[1+(11.8-p_bpcc)K]

when the steam turbine generator unit has external steam supply and the steam extraction port is before cold re-cooling or cold re-cooling:

P_maxc＝P_max[1+(11.8-p_bpcc)K]-G_g(h_g+h_hrh-h_crh-h_ex)/3600

when the steam turbine generator unit has external steam supply and the steam extraction port is after cold again:

P_maxc＝P_max[1+(11.8-p_bpcc)K]-G_g(h_g-h_ex)/3600

in the formula, G_gThe steam supply flow is external; h is_gIs the enthalpy of externally supplied steam; h is_hrhIs the reheat steam enthalpy; h is_crhIs the cold reheat steam enthalpy; h is_exIs the exhaust enthalpy of the low pressure cylinder. h is_g、h_hrh、h_crhThe water and steam meter can be checked according to the corresponding pressure and temperature parameters of the steam turbine generator unit under the current working condition; h is_exCan be dependent on the pressure P_bpccAnd the dryness is 0.92, and the water and steam tables are checked to obtain the dryness.

Step 5, comparing the maximum output P_maxcAnd the output Pc of the steam turbine generator unit under the current working condition_c：

When P is present_maxc≥P_cWhen the residual output space of the steam turbine generator unit is P ═ P_maxc-P_c；

When P is present_maxc<P_cThen the turbo generator set remainsAnd (4) calculating the residual output space of the unit by taking the residual output space as P as 0.

The analysis method of the embodiment mainly comprises the following steps of testing the maximum output and the maximum main steam flow of the unit under the specified conditions; calculating the influence coefficient of the back pressure on the output force; calculating the back pressure of the unit under the maximum main steam flow; calculating the maximum output of the unit under the current working condition; comparing the current output of the unit with the calculated maximum output, and calculating the residual output space of the unit. According to the result, the output space of each unit can be known at any time in summer at the peak-facing degree, so that the generated energy of the units can be reasonably arranged, the units can be ensured to safely and stably operate, the output capacity can be exerted, and the influence of brake-out electricity limiting on the life of people is reduced to the maximum extent.

Fig. 1 shows a system diagram of a steam turbine generator unit, wherein the external steam supply can be led out from any steam extraction ports of a high pressure cylinder, a medium pressure cylinder and a low pressure cylinder. Taking the model N330-17.75/540/540 as an example, the calculation of the output space of the unit under three conditions of no external steam supply, cold steam supply again and hot steam supply again is respectively given, and the result is shown in the following table.

The calculation result of the unit output space when no external steam supply exists is as follows:

the calculation result of the unit output space when the unit supplies steam from cold to outside is as follows:

the calculation result of the unit output space when the unit supplies steam from the heat to the outside is as follows:

in summer time at the peak of the head-on, a dispatching department can know the output space of each unit at any time according to the analysis method disclosed by the invention so as to reasonably arrange the generated energy of the units, ensure that the units can safely and stably run, exert the output capacity and furthest reduce the influence of the brake-out power limitation on the life of people.

The foregoing is only a preferred embodiment of the present invention, and it will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the principle of the present invention, and these modifications and improvements are also considered to be within the scope of the present invention.