Abstract: Aiming at the problems existed in the control of steam in ground torch, a solution is put forward. The method of implementing this control strategy in Honeywell TPS is introduced in detail, and the actual CL program is given. Application results show that this solution is highly reliable and convenient. Provide some reference for solving similar problems.
Keywords: steam flow; Honeywell; PM point; control language DOI: 10.16640 / j.cnki.37-1222 / t.2017.03.042
1 Introduction The plastics plant of Qilu Branch of SINOPEC plans to establish a ground torch system and determine the bid of a certain company through bidding. The torch system uses a steel combustion tower to separate the combustion. Torch maximum design emissions of 150 tons / hour. The outer side of the combustion tower is provided with a concrete windbreak, the combustion tower is designed to self-suction vacuum combustion. Tower body with steel structure, lined with high temperature ceramic fiber module. The combustion tower is equipped with more than 100 units with steam smoke burner inside the combustion tower in part multi-stage emission combustion. During the discharge process, the same level of smoke-reducing steam as the burner is also adjusted synchronously. The operator adjusts the steam regulating valve according to the combustion of the burner in the picture of the camera and changes the smoke-reducing steam flow to achieve the smokeless combustion effect.
The torch adopts multistage emission and combustion. In order to be able to put various levels of burners according to the amount of flare gas emissions, Siemens S7-300 [1] PLC was selected as the controller. The initial programmable controller is mainly used for sequential control [2], now it not only has the logic processing function, but also has the PID operation, constitutes the network and other complex functions [3]. In addition to the ignition button in the control room and the steam control circuit, other data in the field are read by the DCS from the field PLC in a communication mode. Through the DCS in the control room to adjust the amount of steam added, and can effectively monitor the parameters of the ground torch system.
The flare gas is passed through the first stage burner at low flow rates. There are 2 pressure transmitters on the gas collector of the ground torch. When the amount of flare gas exceeds the capacity of the first stage combustion system, the pressure in the main manifold rises and when the pressure reaches the set value, the pneumatic shut-off valve on the second stage combustion system pipeline will open and the ground combustion on it The device will be put into use. As the emissions continue to increase, the pneumatic shut-off valves on the combustion systems at all levels will also be turned on in turn, with more ground burners put into use. When the emissions are reduced, the pneumatic shut-off valves on the combustion systems at all levels will operate in reverse, ie the pneumatic shut-off valves on the final combustion system will be closed first. The PLC also controls the nitrogen purge valve on the line of the combustion system, the constant light pneumatic direct acting valve, the pilot cylinder fuel gas solenoid, and the igniter.
2 raised the issue Due to the uncertainty of the flare gas emissions can not be achieved through automatic control burner smoke-free combustion and save both steam problems, so the steam manually by the operator to open the valve to join. In actual operation, the majority of emissions occur when the plant operation fluctuates. At this time, the operators' efforts are focused on the parts where the process fluctuations occur. The torch may not be able to handle the combustion situation. If the steam valve can not be opened in time, black smoke or even burned burners may occur.
3 Solve the problem According to this demand, we control room DCS through programming, to achieve the steam valve automatically open and close.
The idea of ​​solving the problem is to add a PM (Process Module) point to the conventional control loop, and the PM point automatically assigns the output to meet the conditions, but can not affect the normal operation of the control loop because of the operation of this point. DCS uses Honeywell's TPS system. Ho neywell's TPS system build process is a simple card fill and choose. Users can follow the prompts to fill out the system [4].
3.1 build point HY672
Enter the engineer's main menu, select the Network Interface Module option, select the Process Point Building option, enter the Nim Build Type Select Menu menu, select the type of point Analog Output point, enter the point configuration screen.
First fill the point number HY672, select the node type HPM. Select the full point as the point format, the difference between the full point and the slightest point is the alarm function with the whole point, but not the slightest. Point description, keywords, etc. fill in according to the actual situation. The unit number refers to the establishment of this point to be placed in the system in the management of the unit, network number, node number, module number and slot number is HPM hardware address, according to the system plan to fill in correctly. In the second page of the Point Module Type tab according to the actual choice of hardware type, AO type corresponds to 8 points card; AO_16 type corresponds to 16 points card. On the third page, the Output Direction tab is selected according to the on-off style of the on-site valve, Direct on gas valve and Direct on off valve. Other options to use the default value can be. Press "Ctrl" + "+" Download, exit.
3.2 to establish point HIC672
Under the Nim Build Type Select Menu, select the type of the point as Regulatory Control, and enter the point configuration screen.
Fill in the first page of the bit number, select the node type, point format. Point description, keywords, etc. recommended complete, so that more information about this point can be provided. Unit number, network number, node number correctly filled in according to system planning. The second page of Slotnum fill in the established point on the HPM in the slot address. Select the Automan option in the Co ntrol Algorithm tab. Fill in the number of output terminals on page 7 of the configuration screen. After the Enter key is pressed, a dialog box pops up for parameters of the output point, and fill in TY672.OP. Other parameters using the system default or modified as needed, after downloading, exit.
3.3 to establish a PM point HIC672PM
Under Nim Build Type Select Menu, select Network Interface Module → Process Point Building → Process Module to enter the point configuration screen.
Fill in the first page of the bit number, select the node type. Point description, keywords, etc. recommended complete. The unit number, network number, node number and slot number are correctly filled in according to the system planning. Other parameters are modified by system defaults or modified as needed. After the installation, download and exit.
3.4 CL (Co ntrol language) program In the main menu screen, select the Command Processor option, write CL program:
SEQUENCE HIC672CL (HPM: POINT HIC672PM) EXTERNAL HIC672, HZH672, HZL672
PHASE STARTUP
IF (HZH672.PV = OPEN) AND (HIC672.OP & WAIT NN (10) SECS;
& SET HIC672.MODATTR = PROGRAM;
& SET HIC672.MODE = MAN;
& SET HIC672.OPE = NN (1);
& SET HIC672.MODATTR = OPERATOR)
ELSE IF (HZL672.PV = CLOSE) AND (NN (20) = 1) THEN (
& SET HIC672.MODATTR = PROGRAM;
& SET HIC672.MODE = MAN;
& SET HIC672.OPE = NN (15);
& SET HIC672.MODATTR = OPERATOR)
GOTO PHASE STARTUP
END HIC672CL
Program Description:
NN (1) Open the opening value register, unit:%;
NN (10) Open delay time register, unit: second;
NN (15) Turn off the opening value register, unit:%;
NN (20) Automatically turn off the switch, unit: no outline.
When the pneumatic shut-off valve is open, the program determines if the current opening of the steam valve HV672 (HIC672.OP) is less than the preset value in NN (1). If the current opening of HV672 is not less than the preset value in NN (1), HV672 maintains the current opening; if the current opening of HV672 is smaller than the preset value in NN (1), the program will press NN Set time delay, the default value in NN (1) after delay is assigned to HV672 (HIC672.OP). When the pneumatic shut-off valve is closed, the program judges whether the value in NN (20) equals one. If equal to 1, the default value in NN (15) is assigned to HV672 (HIC672.OP), otherwise the valve position remains unchanged.
Compile the program. If there are errors in the program, follow the system prompts to make changes. Will compile the correct program copy to & E01 directory.
4 system debugging After the completion of the establishment of the point, the need for systematic loopback control system. In order to observe the convenience, the HIC672, HY672, HZH672, HZL672, HIC672PM compiled into a group of operations. Then follow the steps below to complete the debugging:
(1) out of the spot HY672 breakdown, activate this point.
(2) call out HIC672 breakdown, activate this point. Change the value of OP to see whether the OP value of HY672 changes synchronously. HIC672 manual output and on-site school school valve, adjust the valve opening and control room signal is consistent; the school is completed, the HIC672 output to 0;
(3) bring out the HIC672PM breakdown, loading HIC672CL program. Set NN (1) = 10, NN (10) = 5, NN (15) = - 5, NN (20) = 1 and then run the program after the program is loaded.
(4) Manually give signal so that HZH672.PV = OPEN, HZL672.PV = OTHER, observe if HIC672.OP output becomes 10% after 5 seconds delay. After the output of 10% can manually output any number between 10% ~ 100%;
(5) Manually give signal, make HZH672.PV = OTHER, HZL672.PV = CLOSE and observe if HIC672.OP output becomes -5%. Output can not be changed manually after -5% output. After changing the value of NN (20) in HIC672PM is not equal to 1, you can manually output HIC672.OP to any value.
If the program execution result is wrong, check the PM point settings and make the appropriate changes.
5 Conclusion The control strategy implemented in accordance with the above scheme reduces the operating pressure for operators to deal with problems when the device is in production fluctuations, especially the valve opening and closing caused by normal small amount of discharge, and the operator can completely ignore the concern. The practical application in the past year shows that the program is convenient and practical and provides some reference for solving similar problems.
references:
[1] Ango Siemens S7-400H system in the granulation unit of the application [J]. Automation Instrumentation, 2014,35 (10): 34-36.
[2] Li Yuming. Chemical Instrumentation and Automation [M] .4 edition. Beijing: Chemical Industry Press, 2006: 126.
[3] Rhododendron. Measuring Instruments and Automation [M] .2 edition. Shandong: China University of Petroleum Press, 2006: 172.
[4] Ango.MTL data acquisition system in TPS system application [J]. Chemical Industry Automation and Instruments, 2007,34 (03): 78-79.
Keywords: steam flow; Honeywell; PM point; control language DOI: 10.16640 / j.cnki.37-1222 / t.2017.03.042
1 Introduction The plastics plant of Qilu Branch of SINOPEC plans to establish a ground torch system and determine the bid of a certain company through bidding. The torch system uses a steel combustion tower to separate the combustion. Torch maximum design emissions of 150 tons / hour. The outer side of the combustion tower is provided with a concrete windbreak, the combustion tower is designed to self-suction vacuum combustion. Tower body with steel structure, lined with high temperature ceramic fiber module. The combustion tower is equipped with more than 100 units with steam smoke burner inside the combustion tower in part multi-stage emission combustion. During the discharge process, the same level of smoke-reducing steam as the burner is also adjusted synchronously. The operator adjusts the steam regulating valve according to the combustion of the burner in the picture of the camera and changes the smoke-reducing steam flow to achieve the smokeless combustion effect.
The torch adopts multistage emission and combustion. In order to be able to put various levels of burners according to the amount of flare gas emissions, Siemens S7-300 [1] PLC was selected as the controller. The initial programmable controller is mainly used for sequential control [2], now it not only has the logic processing function, but also has the PID operation, constitutes the network and other complex functions [3]. In addition to the ignition button in the control room and the steam control circuit, other data in the field are read by the DCS from the field PLC in a communication mode. Through the DCS in the control room to adjust the amount of steam added, and can effectively monitor the parameters of the ground torch system.
The flare gas is passed through the first stage burner at low flow rates. There are 2 pressure transmitters on the gas collector of the ground torch. When the amount of flare gas exceeds the capacity of the first stage combustion system, the pressure in the main manifold rises and when the pressure reaches the set value, the pneumatic shut-off valve on the second stage combustion system pipeline will open and the ground combustion on it The device will be put into use. As the emissions continue to increase, the pneumatic shut-off valves on the combustion systems at all levels will also be turned on in turn, with more ground burners put into use. When the emissions are reduced, the pneumatic shut-off valves on the combustion systems at all levels will operate in reverse, ie the pneumatic shut-off valves on the final combustion system will be closed first. The PLC also controls the nitrogen purge valve on the line of the combustion system, the constant light pneumatic direct acting valve, the pilot cylinder fuel gas solenoid, and the igniter.
2 raised the issue Due to the uncertainty of the flare gas emissions can not be achieved through automatic control burner smoke-free combustion and save both steam problems, so the steam manually by the operator to open the valve to join. In actual operation, the majority of emissions occur when the plant operation fluctuates. At this time, the operators' efforts are focused on the parts where the process fluctuations occur. The torch may not be able to handle the combustion situation. If the steam valve can not be opened in time, black smoke or even burned burners may occur.
3 Solve the problem According to this demand, we control room DCS through programming, to achieve the steam valve automatically open and close.
The idea of ​​solving the problem is to add a PM (Process Module) point to the conventional control loop, and the PM point automatically assigns the output to meet the conditions, but can not affect the normal operation of the control loop because of the operation of this point. DCS uses Honeywell's TPS system. Ho neywell's TPS system build process is a simple card fill and choose. Users can follow the prompts to fill out the system [4].
3.1 build point HY672
Enter the engineer's main menu, select the Network Interface Module option, select the Process Point Building option, enter the Nim Build Type Select Menu menu, select the type of point Analog Output point, enter the point configuration screen.
First fill the point number HY672, select the node type HPM. Select the full point as the point format, the difference between the full point and the slightest point is the alarm function with the whole point, but not the slightest. Point description, keywords, etc. fill in according to the actual situation. The unit number refers to the establishment of this point to be placed in the system in the management of the unit, network number, node number, module number and slot number is HPM hardware address, according to the system plan to fill in correctly. In the second page of the Point Module Type tab according to the actual choice of hardware type, AO type corresponds to 8 points card; AO_16 type corresponds to 16 points card. On the third page, the Output Direction tab is selected according to the on-off style of the on-site valve, Direct on gas valve and Direct on off valve. Other options to use the default value can be. Press "Ctrl" + "+" Download, exit.
3.2 to establish point HIC672
Under the Nim Build Type Select Menu, select the type of the point as Regulatory Control, and enter the point configuration screen.
Fill in the first page of the bit number, select the node type, point format. Point description, keywords, etc. recommended complete, so that more information about this point can be provided. Unit number, network number, node number correctly filled in according to system planning. The second page of Slotnum fill in the established point on the HPM in the slot address. Select the Automan option in the Co ntrol Algorithm tab. Fill in the number of output terminals on page 7 of the configuration screen. After the Enter key is pressed, a dialog box pops up for parameters of the output point, and fill in TY672.OP. Other parameters using the system default or modified as needed, after downloading, exit.
3.3 to establish a PM point HIC672PM
Under Nim Build Type Select Menu, select Network Interface Module → Process Point Building → Process Module to enter the point configuration screen.
Fill in the first page of the bit number, select the node type. Point description, keywords, etc. recommended complete. The unit number, network number, node number and slot number are correctly filled in according to the system planning. Other parameters are modified by system defaults or modified as needed. After the installation, download and exit.
3.4 CL (Co ntrol language) program In the main menu screen, select the Command Processor option, write CL program:
SEQUENCE HIC672CL (HPM: POINT HIC672PM) EXTERNAL HIC672, HZH672, HZL672
PHASE STARTUP
IF (HZH672.PV = OPEN) AND (HIC672.OP & WAIT NN (10) SECS;
& SET HIC672.MODATTR = PROGRAM;
& SET HIC672.MODE = MAN;
& SET HIC672.OPE = NN (1);
& SET HIC672.MODATTR = OPERATOR)
ELSE IF (HZL672.PV = CLOSE) AND (NN (20) = 1) THEN (
& SET HIC672.MODATTR = PROGRAM;
& SET HIC672.MODE = MAN;
& SET HIC672.OPE = NN (15);
& SET HIC672.MODATTR = OPERATOR)
GOTO PHASE STARTUP
END HIC672CL
Program Description:
NN (1) Open the opening value register, unit:%;
NN (10) Open delay time register, unit: second;
NN (15) Turn off the opening value register, unit:%;
NN (20) Automatically turn off the switch, unit: no outline.
When the pneumatic shut-off valve is open, the program determines if the current opening of the steam valve HV672 (HIC672.OP) is less than the preset value in NN (1). If the current opening of HV672 is not less than the preset value in NN (1), HV672 maintains the current opening; if the current opening of HV672 is smaller than the preset value in NN (1), the program will press NN Set time delay, the default value in NN (1) after delay is assigned to HV672 (HIC672.OP). When the pneumatic shut-off valve is closed, the program judges whether the value in NN (20) equals one. If equal to 1, the default value in NN (15) is assigned to HV672 (HIC672.OP), otherwise the valve position remains unchanged.
Compile the program. If there are errors in the program, follow the system prompts to make changes. Will compile the correct program copy to & E01 directory.
4 system debugging After the completion of the establishment of the point, the need for systematic loopback control system. In order to observe the convenience, the HIC672, HY672, HZH672, HZL672, HIC672PM compiled into a group of operations. Then follow the steps below to complete the debugging:
(1) out of the spot HY672 breakdown, activate this point.
(2) call out HIC672 breakdown, activate this point. Change the value of OP to see whether the OP value of HY672 changes synchronously. HIC672 manual output and on-site school school valve, adjust the valve opening and control room signal is consistent; the school is completed, the HIC672 output to 0;
(3) bring out the HIC672PM breakdown, loading HIC672CL program. Set NN (1) = 10, NN (10) = 5, NN (15) = - 5, NN (20) = 1 and then run the program after the program is loaded.
(4) Manually give signal so that HZH672.PV = OPEN, HZL672.PV = OTHER, observe if HIC672.OP output becomes 10% after 5 seconds delay. After the output of 10% can manually output any number between 10% ~ 100%;
(5) Manually give signal, make HZH672.PV = OTHER, HZL672.PV = CLOSE and observe if HIC672.OP output becomes -5%. Output can not be changed manually after -5% output. After changing the value of NN (20) in HIC672PM is not equal to 1, you can manually output HIC672.OP to any value.
If the program execution result is wrong, check the PM point settings and make the appropriate changes.
5 Conclusion The control strategy implemented in accordance with the above scheme reduces the operating pressure for operators to deal with problems when the device is in production fluctuations, especially the valve opening and closing caused by normal small amount of discharge, and the operator can completely ignore the concern. The practical application in the past year shows that the program is convenient and practical and provides some reference for solving similar problems.
references:
[1] Ango Siemens S7-400H system in the granulation unit of the application [J]. Automation Instrumentation, 2014,35 (10): 34-36.
[2] Li Yuming. Chemical Instrumentation and Automation [M] .4 edition. Beijing: Chemical Industry Press, 2006: 126.
[3] Rhododendron. Measuring Instruments and Automation [M] .2 edition. Shandong: China University of Petroleum Press, 2006: 172.
[4] Ango.MTL data acquisition system in TPS system application [J]. Chemical Industry Automation and Instruments, 2007,34 (03): 78-79.
Since the height of the filling is close to the tower top, the water eliminator does not occupy much space, and the overall height of the cross-flow tower is small, which makes it relatively compact compared with counter flow type, and therefore lower air inlet speed and power consumption as well.
The cross-flow tower adopts a water distribution system that will let the water drop fall naturally by gravity. Thereby, water distribution holes are not easy to be blocked, as water distribution is even and maximizes the performance of the tower fillings. The inspection manhole also enables routinely maintenance without machine shutdown.
A lower part of the cross-flow tower filling is submerged in the water, so that the water flows through the surface of the filling and directly falls into the below tank, making low noise.
The cross-flow tower fan is located in the middle of the Cooling Tower, while the filling, on both sides of the tower. So the amount of splashing water is very small.
Cross Flow Cooling Tower,Cooling Tower Cools Water,Induced Draught Cooling Tower,Induced Draft Cross Flow Cooling Tower
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