阅读说明：本技术 低压蒸汽无感化调节方法 (Low-pressure steam non-inductive adjusting method ) 是由 殷青云 郭辉 吴炜 竞剑锋 于 2020-04-08 设计创作，主要内容包括：本发明涉及一种低压蒸汽无感化调节方法,包括以下步骤：安装电动调节执行机构、流量采集变送装置以及各个传感器,搭建3#汽轮发电机控制室、炼钢区域和锅炉区域的信号传输网络；当管网压力OG压力大于1.01MPa时,所述低压管网蒸汽调节阀采用根据PT6003压力自动控制,当管网压力OG压力小于或等于0.99MPa时,所述低压管网蒸汽调节阀采用OG蒸汽压力线性调节。当3#锅炉低压蒸汽压力大于0.38MPa时,所述石灰蒸汽调门采用根据3#锅炉低压蒸汽压力自动调节,当3#锅炉低压蒸汽压力小于0.36Mpa或OG压力小于或等于1.05MPa时,所述石灰蒸汽调门采用OG蒸汽压力线性调节。本发明能够实现低压蒸汽全回收和零放散。(The invention relates to a low-pressure steam non-inductive adjusting method, which comprises the following steps: installing an electric adjusting actuating mechanism, a flow acquisition and transmission device and various sensors, and building a 3# steam turbine generator control room, a steel-making area and a boiler area; when the OG pressure of the pipe network is greater than 1.01MPa, the low-pressure pipe network steam regulating valve is automatically controlled according to the PT6003 pressure, and when the OG pressure of the pipe network is less than or equal to 0.99MPa, the low-pressure pipe network steam regulating valve is linearly regulated by the OG steam pressure. When the low-pressure steam pressure of the 3# boiler is greater than 0.38MPa, the lime steam control door is automatically adjusted according to the low-pressure steam pressure of the 3# boiler, and when the low-pressure steam pressure of the 3# boiler is less than 0.36MPa or OG pressure is less than or equal to 1.05MPa, the lime steam control door is linearly adjusted according to the OG steam pressure. The invention can realize the full recovery and zero diffusion of low-pressure steam.)

1. A low-pressure steam non-inductive adjusting method is characterized by comprising the following steps:

(1) an electric adjusting actuating mechanism and a flow acquisition and transmission device are installed and used for adjusting and monitoring the consumption of low-pressure steam supplement of the 3# steam turbine generator converged by the low-pressure pipe network steam adjusting valve; installing an OG system heat accumulator main pipe pressure sensor, an OG steam cylinder pressure sensor and an OG steam pipe network pressure sensor in a steelmaking area;

(2) building a 3# steam turbine generator control room, a steel-making area and a boiler area;

(3) the control logic of the low-pressure pipe network steam regulating valve is as follows: when the OG pressure of the pipe network is greater than 1.01MPa, the low-pressure pipe network steam regulating valve is automatically controlled according to the PT6003 pressure, and when the OG pressure of the pipe network is less than or equal to 0.99MPa, the low-pressure pipe network steam regulating valve is linearly regulated by the OG steam pressure;

(4) the control logic of the lime steam governing valve is as follows: when the low-pressure steam pressure of the 3# boiler is greater than 0.38MPa, the lime steam control door is automatically adjusted according to the low-pressure steam pressure of the 3# boiler, and when the low-pressure steam pressure of the 3# boiler is less than 0.36MPa or OG pressure is less than or equal to 1.05MPa, the lime steam control door is linearly adjusted according to the OG steam pressure.

2. The low-pressure steam non-inductive adjusting method according to claim 1, wherein logic parameters are adjusted by referring to an existing seawall side steam adjusting valve when the low-pressure pipe network steam adjusting valve in the step (3) adopts OG steam pressure linear adjustment.

3. The low pressure steam non-sensible adjustment method of claim 1, characterized in that, when the lime steam governor in step (4) is linearly adjusted by using OG steam pressure, the logical parameters are adjusted with reference to the existing lime side steam governor.

4. The low-pressure steam non-inductive adjusting method according to claim 1, further comprising the step of causing overpressure protection of a 3# machine steam-distributing cylinder and a 3# boiler low-pressure steam drum when completing high-flow steam supplement of low-pressure steam, wherein the control logic is as follows: when the low-pressure steam pressure and the low-pressure header pressure of the 3# boiler are both greater than 0.4MPa, the lime side steam-supplementing regulating valve is forcibly closed to 20%, and when the low-pressure main steam pressure is less than 0.35MPa, the lime side steam-supplementing regulating valve returns to automatically operate; when the pressure of the cylinder is greater than 0.4MPa, the sea wall side adjusting valve is automatically forced to be closed to 0%, and when the pressure of the cylinder is less than 0.3MPa, the sea wall side adjusting valve is automatically restored to operate.

5. The low-pressure steam non-inductive regulation method according to claim 1, further comprising a coking plant area low-pressure steam control logic, specifically as follows: when the steam extraction flow of a CDQ unit of the coke-oven plant is more than 5t/h and the inlet pressure of a temperature and pressure reducing device of the coke-oven plant is more than 0.4MPa, the steam supplementing control pressure at the sea wall side is 0.35 MPa; when the steam extraction flow of a CDQ unit of the coke-oven plant is more than 5t/h and the inlet pressure of a temperature and pressure reducing device of the coke-oven plant is less than or equal to 0.4MPa, the steam supplementing control pressure at the sea wall side is 0.55 MPa; when the steam extraction flow of the CDQ unit of the coking plant is less than or equal to 5t/h, PID control is started, and the inlet of the pressure reducer is maintained at 0.45MPa through cascade regulation.

Technical Field

The invention relates to the technical field of steam recovery, in particular to a low-pressure steam non-inductive adjusting method.

Background

The low-pressure pipe network layout of a steel mill is long, the steam output and self-consumption regulation rate of a steel-making area are high, the current mode is dispatching, uploading and issuing, unified dispatching and regulation are realized, a 3# machine is used according to instructions, and finally the overpressure relief quantity of a heat accumulator is large due to regulation lag;

at present, the steam production and the steam consumption of a low-pressure steam pipe network of a company are only monitored in an EMS system, and a unified monitoring and control platform is not formed, so that the old modes of personnel scheduling and telephone communication are not applicable, and the recovery and the use of the steam of the whole plant are influenced finally; the main steam source of the steam for the coking plant area is used for CDQ steam extraction and main plant area steam supply, is relatively isolated relative to the main plant area and becomes a monitoring blind area for low-pressure steam unified management; manual scheduling does not form a platform for uniform automatic control, so that the pressure fluctuation of a low-pressure pipe network is large, and the quality of external supply of steam is influenced.

Disclosure of Invention

The invention provides a low-pressure steam non-inductive adjusting method which can realize full recovery and zero emission of low-pressure steam.

The technical scheme adopted by the invention for solving the technical problems is as follows: the low-pressure steam non-inductance adjusting method comprises the following steps:

(1) an electric adjusting actuating mechanism and a flow acquisition and transmission device are installed and used for adjusting and monitoring the consumption of low-pressure steam supplement of the 3# steam turbine generator converged by the low-pressure pipe network steam adjusting valve; installing an OG system heat accumulator main pipe pressure sensor, an OG steam cylinder pressure sensor and an OG steam pipe network pressure sensor in a steelmaking area;

(2) building a 3# steam turbine generator control room, a steel-making area and a boiler area;

(3) the control logic of the low-pressure pipe network steam regulating valve is as follows: when the OG pressure of the pipe network is greater than 1.01MPa, the low-pressure pipe network steam regulating valve is automatically controlled according to the PT6003 pressure, and when the OG pressure of the pipe network is less than or equal to 0.99MPa, the low-pressure pipe network steam regulating valve is linearly regulated by the OG steam pressure;

(4) the control logic of the lime steam governing valve is as follows: when the low-pressure steam pressure of the 3# boiler is greater than 0.38MPa, the lime steam control door is automatically adjusted according to the low-pressure steam pressure of the 3# boiler, and when the low-pressure steam pressure of the 3# boiler is less than 0.36MPa or OG pressure is less than or equal to 1.05MPa, the lime steam control door is linearly adjusted according to the OG steam pressure.

And (3) adjusting logic parameters of the low-pressure pipe network steam adjusting valve in the step (3) by referring to the existing sea wall side steam adjusting valve when the OG steam pressure is linearly adjusted.

And (4) adjusting logic parameters by referring to the existing lime side steam adjusting valve when the lime steam adjusting valve is linearly adjusted by OG steam pressure.

The low-pressure steam non-inductive adjusting method further comprises the step of causing overpressure protection of a 3# machine cylinder and a 3# boiler low-pressure steam pocket when improving the high-flow steam supplement of the low-pressure steam, wherein the control logic is as follows: when the low-pressure steam pressure and the low-pressure header pressure of the 3# boiler are both greater than 0.4MPa, the lime side steam-supplementing regulating valve is forcibly closed to 20%, and when the low-pressure main steam pressure is less than 0.35MPa, the lime side steam-supplementing regulating valve returns to automatically operate; when the pressure of the cylinder is greater than 0.4MPa, the sea wall side adjusting valve is automatically forced to be closed to 0%, and when the pressure of the cylinder is less than 0.3MPa, the sea wall side adjusting valve is automatically restored to operate.

The low-pressure steam non-inductive adjusting method further comprises a low-pressure steam control logic of the coking plant area, and the method specifically comprises the following steps: when the steam extraction flow of a CDQ unit of the coke-oven plant is more than 5t/h and the inlet pressure of a temperature and pressure reducing device of the coke-oven plant is more than 0.4MPa, the steam supplementing control pressure at the sea wall side is 0.35 MPa; when the steam extraction flow of a CDQ unit of the coke-oven plant is more than 5t/h and the inlet pressure of a temperature and pressure reducing device of the coke-oven plant is less than or equal to 0.4MPa, the steam supplementing control pressure at the sea wall side is 0.55 MPa; when the steam extraction flow of the CDQ unit of the coking plant is less than or equal to 5t/h, PID control is started, and the inlet of the pressure reducer is maintained at 0.45MPa through cascade regulation.

Advantageous effects

Due to the adoption of the technical scheme, compared with the prior art, the invention has the following advantages and positive effects: the invention adopts wireless transmission technology to collect data: the 3# machine control system is collected in a centralized mode according to the conditions of main steam generation sources, steam extraction sources and steam utilization sources, pressure and flow of the whole plant, a wireless transmission networking system for low-pressure pipe network detection is formed, seamless butt joint among multiple regions of the whole plant is facilitated, corresponding measuring points are added and deleted flexibly, and the engineering quantity is small.

The invention realizes the full recovery and zero emission of low-pressure steam of the whole company: by the biggest low pressure steam user of whole factory, 3# turbo generator comes the balance of unified automatic control whole low pressure pipe network, forms perfect protection and control logic, accomplishes the healthy operation of low pressure pipe network, realizes the intelligent regulation platform of zero diffusion, the biggest recovery, zero personnel's intervention, for ordinary dispatch regulation, reduces advantages such as human cost, quick response.

Drawings

Fig. 1 is an overall layout diagram of a wireless device of the present invention.

Detailed Description

The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Further, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teaching of the present invention, and such equivalents may fall within the scope of the present invention as defined in the appended claims.

The embodiment of the invention relates to a low-pressure steam non-inductive adjusting method, which adopts a wireless transmission technology to collect data: the 3# machine control system is collected in a centralized mode according to the conditions of main steam generation sources, steam extraction sources and steam utilization sources, pressure and flow of the whole plant, a wireless transmission networking system for low-pressure pipe network detection is formed, seamless butt joint among multiple regions of the whole plant is facilitated, corresponding measuring points are added and deleted flexibly, and the engineering quantity is small. The method of the invention realizes the low-pressure steam full recovery and zero emission of the whole company: by the biggest low pressure steam user of whole factory, 3# turbo generator comes the balance of unified automatic control whole low pressure pipe network, forms perfect protection and control logic, accomplishes the healthy operation of low pressure pipe network, realizes the intelligent regulation platform of zero diffusion, the biggest recovery, zero personnel's intervention, for ordinary dispatch regulation, reduces advantages such as human cost, quick response. The specific scheme is as follows:

1. implementation of remote signal transmission

In order to solve the defects in the Ninggang low-pressure steam pipe network, OG steam recovery is improved. Firstly, an electric adjusting actuating mechanism and a flow acquisition and transmission device are installed in a long distance and are used for adjusting and monitoring the consumption of low-pressure steam of a low-pressure pipe network of a company which is converged into a 3# steam turbine generator for low-pressure steam compensation. Secondly, combining the characteristics of steel mill low pressure steam production, OG boiler steam has great diffusion, and average daily diffusion is more than 30, causes huge waste, so in steelmaking converter region, need newly-increased 3 signals to power plant 3# unit, be OG system heat accumulator female pipe pressure, OG steam gas cylinder pressure, OG steam pipe network pressure respectively for the change condition of monitoring low pressure pipe network source. By combining the above 2 measures, the linear distance from the OG signal to the control room is about 3km, and the linear distance from the regulating valve and the flow signal to the control room is about 1 km.

Remote wireless transmission scheme

The first stage is as follows:

through multi-party consultation and comparison, the embodiment is improved by adopting a point-to-point wireless analog quantity signal transmission terminal of Xiandatai electronic Limited liability company, the model numbers are DTD110FC and 4-channel analog quantity modules respectively, the theoretical transmission distance is 3km, and 2 pairs are adopted; the ultra-long distance DTD110FEY, a 4-channel analog quantity module, the transmission distance of 5km and 1 pair are adopted. The specific arrangement is as follows:

1) an OG heat accumulator pressure signal and an OG cylinder pressure signal are converted by a steel-making PLC400 controller in a steel-making converter control room, a cable is connected to a transmitting end of an ultra-long-distance wireless transmission device, a corresponding receiving end device is installed at the top of a 3# machine control room plant and is connected to a PLC cabinet by the cable, and long-distance wireless transmission of the OG signal is realized;

2) a transmitting end of remote wireless equipment with the model number of DTD110FC is installed in a 3# machine control room, and a corresponding receiving end is installed on the side of the regulating valve to realize the transmission of the wireless control instruction of the regulating valve;

3) in the previous experiment, because signal interference exists in the centralized arrangement of the wireless signal device at the 3# machine factory building side, in the embodiment, the communication optical cable signal between the 3# boiler and the 3# steam engine is fully utilized, the transmitting end with the model of DTD110FC is installed at the regulating valve site for the flow meter signal and the regulating valve position feedback signal, the wireless receiving device is arranged at the 3# boiler side, the original arrangement optical fiber is utilized, and the two-point signal is introduced to the 3# machine, and the specific arrangement is shown in fig. 1.

4) Frequency band setting of the wireless device: the DTD110 series wireless analog quantity transmission device is provided with 3-bit dial switches, and the total number of the 3-bit dial switches is 8, as shown in Table 1.

TABLE 1 radio frequency band setting table

Channel number	frequency/MHz
		SW1_456＝000(0)	430.2000
SW1_456＝000(1)	431.4288
		SW1_456＝000(2)	431.7360
SW1_456＝000(3)	430.5072
		SW1_456＝000(4)	434.6940
SW1_456＝000(5)	434.2332
		SW1_456＝000(6)	433.1580
SW1_456＝000(7)	433.9260

According to the actual installation layout on site, the interference between each signal is overcome, and the specific frequency band setting is shown in table 2.

TABLE 2 actual radio frequency band design table

And a second stage:

after the successful implementation of the first stage, in order to facilitate the subsequent capacity expansion of the low-pressure pipe network monitoring, the diversification and integration are realized, and in the second stage, part of wireless transmission equipment is upgraded and transformed, and finally networking operation is formed.

1) The lime side low-pressure steam regulating valve is controlled by two original sets of one-way wireless equipment to realize instruction and feedback transmission, and is upgraded to two-way analog quantity wireless transmission, the model DTD110FEY-T4AI/4AO, and the transmission flow is simplified.

2) Upgrading the wireless device in the existing converter area, adopting 6-sending and 1-receiving one-way many-to-one terminal, and transmitting terminal model: DTD110FUY-T4AI, receiving end model: the DTD110FUY-R24AO adopts a unified frequency band centralized networking. The receiving end is arranged in a No. 3 machine area, and the No. 1 transmitting end is arranged outside a steelmaking converter control room and is used for the pressure of a heat accumulator of a steelmaking OG system, the pressure of a gas distributing cylinder and the pressure of a pipe network of the gas distributing cylinder; the generator 2 is arranged outside a main control building of a coking plant and is used for reducing the inlet pressure of a coking temperature and pressure device; the generator 3 is arranged on the outer side of the dry quenching electric tower and is used for steam extraction flow and pressure transmission of the CDQ generator. The specific set frequency band is shown in table 3.

Table 3 optimized radio frequency band design table

Implementation of OG control logic

Because there is no absolute regulation relation between the regulated quantity OG pressure signal in the control system and the lime side regulating valve to be regulated (namely, the OG pressure is influenced by the production rhythm of steel smelting), in the automatic design, the Y-X linear relation logic regulation is used instead of the conventional PID regulation.

The first stage is as follows:

2.1 pipe network steam regulating valve PCV6004 control logic:

1) when the OG pressure of the pipe network is greater than 1.01MP, the PCV6004 of the pipe network steam regulating valve is automatically controlled according to the PT6003 pressure, and the pressure is set by operation; 2) when the OG pressure of the pipe network is less than or equal to 0.99MPa, the PCV6004 of the pipe network steam regulating valve is linearly regulated by adopting the OG steam pressure, and the logic parameters are regulated by referring to the existing sea wall side steam regulating valve, as shown in Table 4.

TABLE 4 sea wall side steam regulating valve regulating logic parameter table

OG pressure/MPa	Opening degree of lime adjusting door
		0.85	0
0.9	10
		1.0	50
1.1	80
		1.12	100
2.0	100

2.2 lime steam damper PCV6020 control logic:

1) when the low-pressure steam pressure PT2006 of the 3# boiler is greater than 0.38MPa (3S pulses are added during condition switching, the same is applied below), the lime steam damper PCV6020 automatically adjusts according to the low-pressure steam pressure PT2006 of the 3# boiler, and the set pressure is set by operation; 2) when the low-pressure steam pressure PT2006 of the 3# boiler is less than 0.36MPa or the OG pressure is less than or equal to 1.05MPa, the lime steam regulating valve PCV6020 adopts OG steam pressure linear regulation, and the logic parameters are regulated by referring to the existing lime side steam regulating valve, as shown in Table 5.

TABLE 5 lime side steam regulating valve adjusting logic parameter table

In order to ensure the safe and normal operation of the branch cylinder, the following steps are added: when the grid-connected switch of the generator is opened or the pressure of the cylinder is greater than 0.35MPa, the lime steam control valve PCV6020 and the pipe network steam control valve PCV6004 are closed in a linkage manner to rapidly reduce the steam quantity and maintain the pressure of the cylinder at a normal level.

And a second stage:

when the low-pressure steam and the large-flow steam supplement are perfected, the overpressure protection of the 3# machine steam-distributing cylinder and the 3# boiler low-pressure steam drum is caused.

1) Perfecting the low-pressure steam compensation control logic: when the low-pressure steam pressure PT2006 and the low-pressure header pressure PT2003 of the 3# boiler are greater than 0.4MPa (the low-pressure header safety valve operates at 0.416 MPa), the lime side steam supply regulating valve is forcibly closed to 20%, and when the low-pressure main steam pressure is less than 0.35MPa, the lime side automatically operates again.

2) When the low-pressure steam pressure PT2006 and the low-pressure header pressure PT2003 of the 3# boiler are greater than 0.4MPa, the light character board gives an alarm, namely the low-pressure header pressure is high, and the lime side is forcibly closed to supplement steam.

3) The pressure PT6005 of the gas distributing cylinder is more than 0.4MPa, the adjusting valve at the side of the seawall is automatically and forcibly closed to 0 percent, and the light character plate is triggered to alarm that the pressure of the gas distributing cylinder is high and the gas supply at the side of the seawall is forcibly closed; when the pressure PT6005 of the gas distributing cylinder is less than 0.3MPa, the adjusting valve at the side of the sea wall automatically operates.

Adding a low-pressure steam control logic of a coking plant area: 1) the 3# control system program adds two signals of inlet pressure 1 and inlet pressure 2 of the temperature and pressure reducing device of the coke-oven plant, and adds a steam extraction pressure and flow signal of a CDQ unit of the coke-oven plant; 2) and the control logic of the new temperature-increasing pressure-reducing inlet pressure automatic control is shown in the table 6. 3) The temperature in summer and winter is high and low, the demand of the coking plant area to low-pressure steam is different, automatic control logic is perfected, two different control parameters in summer and winter are started according to the demand, and the generated energy of the CDQ and the 3# machine is increased to the maximum extent on the premise of meeting the steam demand of the coking plant area.

TABLE 6 automatic constant pressure logic table for coking temperature and pressure reducing device

The low-pressure steam pipe network of Ningbo Steel Limited company has 10 kilometers in total, and through internal test optimization, a measuring point is covered by the whole pipe network. The steam supply quantity of the 3# machine low-pressure pipe network is more than 70t/h during steam generation, the mean value of the power generation load is more than 13MW, the power generation load is estimated to be increased by about 3.5MW compared with the previous year, the benefit of annual power generation increase is about 1500 ten thousand yuan, and the economic benefit and the energy-saving effect are very obvious.

The system of low pressure steam is attacked and is closed and continuously optimize the adjustment, and 3# machine low pressure pipe network has realized the monitoring of whole network, and automatic tracking, automatically regulated, independently judge, the intelligent low pressure pipe network control technology of functions such as undisturbed switching, not only finally realized the target that company OG steam "zero" diffuses, make 3# unit generated energy improve by a wide margin, eliminated the noise pollution that steam diffuses and bring moreover. Under the new trend of making the company excellent and strongest, the method makes outstanding contributions to the aspects of deeply developing energy conservation and emission reduction, cost reduction and efficiency improvement, intelligent manufacturing, robot exchange and the like.