KR200272221Y1 - Apparatus for automatic controlling oxygen-output in oxygen manufacture equipment - Google Patents

Abstract

The present invention performs automatic control of oxygen production in the state of maintaining high purity and stable temperature while monitoring the whole process of air supply and oxygen output by performing automatic control according to the oxygen production increase and decrease target set in advance in oxygen production equipment. The present invention relates to an automatic control apparatus for oxygen production in an oxygen production facility.

According to the present invention, when the production of oxygen in the oxygen plant is increased or decreased, if the target amount is set, the control system automatically operates to maintain the entire process in a stable manner. (CONTROL) secured breakthrough control technology in the operation of oxygen plant by eliminating the poor purity and temperature and flow hunting (HUNTING) caused by the increase / decrease. It contributed and brought down the oxygen production cost.

Description

Apparatus for automatic controlling oxygen-output in oxygen manufacture equipment

The present invention relates to a device for controlling oxygen and nitrogen production facilities (hereinafter referred to as "oxygen production facilities") using the temperature difference between the atmospheric air, in particular the oxygen production target set in advance in the oxygen production facilities The automatic control of oxygen production in the oxygen production facility to monitor the entire process of air supply and oxygen output and to carry out the automatic increase / decrease operation of the oxygen production while maintaining high purity and stable temperature accordingly. It is about.

In general, the oxygen plant uses oxygen in the atmosphere to produce oxygen and nitrogen. In the facility that produces a large amount of product gas, oxygen and nitrogen separation methods using temperature boiling points are used. Looking at briefly the control of the conventional oxygen production equipment for producing oxygen and nitrogen as follows.

1 is a configuration diagram of an oxygen production amount control apparatus in a conventional oxygen production facility. Referring to FIG. 1, the air compressed in the air compressor 10 by the air in the atmosphere is an air amount detector 21 and an air amount control valve 23. After being provided to the air separation device 30, the air continues to fall while moving down to -174 ℃ down (down), the temperature is further reduced in the rectifier of the air separation device (30) Oxygen gas is separated and produced at -183 ℃ and nitrogen is produced at -195 ℃. Since the air in the atmosphere is approximately 21% oxygen and 79% nitrogen, the air supplied to the air separator 30 is required for oxygen production.

Since the nitrogen production amount is the same as the oxygen production amount, most of the nitrogen is released into the atmosphere, and the amount of air supplied to the air separator 30 has an important effect on the temperature balance of the entire process and also the quality of the produced oxygen and nitrogen gas. The amount of air supplied and the quantity of product gas produced are always closely related. In addition, the flow rate of each process affects the quality of the produced gas and maintains the temperature balance throughout the process. Therefore, the flow rate of the entire process must be maintained according to the design value according to the oxygen production during the normal operation of the plant.

On the other hand, the flow control loop (LOOP), which affects the quality of oxygen and nitrogen gas produced in the plant operation, first of all, the air intake flow is the most important, and then the oxygen production, nitrogen production, and net nitrogen reflux. Impurity, reflux of nitrogen, liquid air level, cold generation, crude argon flow, crude argon production, etc.

In particular, in the operation of oxygen plant (PLANT), during normal operation, the production gas is constantly produced according to the standard production capacity, but sometimes in the plant using the product gas, when the usage decreases, the produced gas is released to the atmosphere. do. Therefore, if the consumption decreases, the production cost will rise if the output is continuously released to the atmosphere. In this case, it is necessary to reduce the amount of product gas produced.

For this reason, when increasing or decreasing the production amount, the air intake flow rate and the gas production amount must be increased or decreased, and the reflux amount or the generation amount in each process must be increased or decreased at the same time. Here is a closer look at it.

First of all, the oxygen and nitrogen produced in the oxygen production facility should be above the prescribed value, the oxygen should be 99.6% or more and the nitrogen should be 99.999% or more. And, if the quality of the product gas produced in the oxygen production equipment is less than the specified value, it is treated as bad and dissipated to the atmosphere.

Therefore, the most important factor in the operation of oxygen production facilities is the quality of the product gas. Therefore, the highest priority in increasing or decreasing the oxygen production is the maintenance of purity. The influence on the purity of oxygen and nitrogen gas is the temperature balance of each process and each process. The most important and important factor is to control the optimum control time of the increase / decrease operation to prevent the generation of atmospheric emissions due to poor purity during the production increase / decrease operation by the flow rate of the gas flowing in the gas.

Usually, 21% of oxygen is contained in the air, but since it is practically impossible to completely separate oxygen, the separation in the oxygen production facility is regarded as 18% as the ideal separation. As a result, in the case of an oxygen manufacturing facility designed to produce oxygen at 30,000 NM3 per hour, the amount of air introduced is 166,000 NM3 / H.

When the oxygen production amount is 30,000 NM 3 / H, the flow rate required for each process is as follows.

Atmospheric intake air volume: 166,600 NM3 / H

Crude inflow: 28,000 NM3 / H

Cooling generation: 18,000 NM3 / H

Bottom liquid hole liquid level: 45%

Net nitrogen reflux: 8,900 NM3 / H

Impurity nitrogen reflux: 45,000 NM3 / H

Net Nitrogen Production: 30,000 NM3 / H

Oxygen production: 30,000 NM3 / H

Crude Production: 680 NM3 / H

Each flow rate is the flow rate when normal operation is carried out based on the oxygen production rate of 30,000 NM3 / H in the oxygen production apparatus. Therefore, when the oxygen production rate is increased or decreased, the purity of each process is monitored at the standard operating flow rate. With the experience and know-how of the driver, we can change the amount of oxygen produced by manual operation and increase and decrease at the same time.

First, the amount of oxygen production is determined, and the amount of air is calculated according to the amount of oxygen (air change = oxygen change x 5.555). In addition, roughly calculate how much to set each flow controller setting for air volume. Based on this randomly calculated value, the ratio is gradually distributed and the setpoint is input to each controller.

In addition, it is the purity of the produced gas to pay attention to the increase and decrease of the production volume, so to operate the oxygen flow controller, monitor the oxygen purity indicator and stop the increase and decrease when there is a purity change. To start.

In this way, monitor the nitrogen purity indicator when operating the nitrogen flow regulator, monitor and operate the argon purity indicator when operating the argon flow controller, and monitor and adjust the impure nitrogen purity indicator when operating the impurity nitrogen reflux controller. When operating the argon inflow regulator, monitor the crude tube purity indicator and increase / decrease operation.

In such a conventional method, although oxygen production is continuously and continuously produced in operating an oxygen production facility, it is necessary to reduce or increase the production when the amount of usage changes in a plant using the produced gas. Since this is closely related to the increase in oxygen production cost, it is the most desirable operation to adjust the output to the amount of usage if possible.

However, if the production volume is increased or decreased, the temperature and purity of each process are judged, and the flow rate of each process is increased. If a large amount is changed, the temperature balance is collapsed. There was a number of problems, such as the inability to operate at the same time as it is impossible to operate at the same time, due to the experience of setting the flow rate, and the risk of product purity is very high. There was a problem.

The present invention has been devised to solve the above problems, and therefore, the object of the present invention is to manually set the value of the flow controller while monitoring the temperature and purity of each process by the operator's experience when increasing or decreasing the oxygen output of the oxygen production facility. When the oxygen production increase / decrease target is set, the control device operates automatically to monitor the whole process, and the oxygen production automatic control device in the oxygen production facility which enables the automatic production increase / decrease operation with stable purity and temperature in a short time To provide.

1 is a configuration diagram of an oxygen production amount control apparatus in a conventional oxygen production facility.

2 is a block diagram of an automatic oxygen production amount control apparatus in the oxygen production facility according to the present invention.

3 is a detailed configuration diagram of the oxygen production automatic control unit of FIG.

4a and 4b is a graph showing the automatic production increase and reduction speed according to the present invention.

5a and 5b is a graph showing the purity of the oxygen increase and oxygen reduction according to the present invention.

Explanation of symbols on the main parts of the drawings

10: air compressor 20: air volume detection and regulator

30: air separator 40: oxygen amount detection and regulator

50: nitrogen amount detection and regulator 60: argon amount detection and regulator

100: automatic oxygen production unit 101: I / V conversion unit

102: target value setting unit 103: deviation comparator

104: automatic selection switch 105: weight loss setting section

106: increase setting unit 107: timer

108: output unit 120: oxygen amount corrector

140: nitrogen amount corrector 150: nitrogen amount corrector

160: argon amount corrector

As a technical means for achieving the above object of the present invention, the apparatus of the present invention, the air compressor for supplying the compressed air, the air amount detection to detect the air amount supplied from the air compressor to adjust to a predetermined value and A regulator, an air separator for separating and supplying air from the air compressor into oxygen, nitrogen, and argon, respectively, and an oxygen amount detection for detecting an oxygen amount, a nitrogen amount, and an argon amount of the air separator, respectively, and adjusting them to a preset value. And an oxygen production facility including a regulator, a nitrogen amount detector and a regulator, and an argon amount detector and a regulator, the apparatus comprising: an I / V converter for converting a current signal corresponding to the amount of oxygen detected by the oxygen amount detector and the regulator into a voltage; A target value setting unit for setting an oxygen production target amount, an output value of the I / V conversion unit, and a target of the target value setting unit; A deviation comparator for outputting a deviation from the output, a weight loss setting unit for setting the oxygen production loss, an weight increase setting unit for setting the oxygen production increase, and a weight loss value or the weight increase setting according to the output level of the deviation comparator An oxygen production automatic control unit including an automatic selection switch for selecting a negative increase value and outputting the result to each corrector; An air amount corrector which multiplies the output value of the oxygen production automatic control unit with a preset value and provides the air amount detector as an adder of the air amount control system of the air amount detection and regulator; An oxygen amount corrector which multiplies an output value of the oxygen production automatic control unit with a preset value and provides the oxygen amount detector as an adder of an oxygen amount control system of the oxygen amount detection and regulator; A nitrogen amount corrector which multiplies the output value of the oxygen production automatic control unit with a preset value and provides the nitrogen amount detector and the adder of the nitrogen amount control system of the regulator; An argon amount corrector which multiplies an output value of the oxygen production automatic control unit with a preset value and provides the argon amount detector as an adder of the argon amount control system of the argon amount detector; Characterized in having a.

Hereinafter, an automatic oxygen production amount control apparatus in an oxygen production facility according to the present invention will be described in detail with reference to the accompanying drawings. In the drawings referred to in the present invention, components having substantially the same configuration and function will use the same reference numerals.

2 is a block diagram of an automatic oxygen production amount control apparatus in the oxygen production facility according to the present invention, referring to Figure 2, the oxygen production facility applied to the present invention is an air compressor (10) for supplying compressed air, Detects and adjusts the air amount supplied from the air compressor 10 to a preset value, and the air amount detector 20 and the air from the air compressor 10 to separate and supply the oxygen, nitrogen and argon, respectively Oxygen amount detection and control unit 40, nitrogen amount detection and control unit 50 and argon to detect the oxygen amount, nitrogen amount and argon amount of the air separation device 30 and the air separation device 30, respectively, and adjust them to preset values. It is composed of a quantity detection and regulator (60).

The air amount detector and regulator 20, the oxygen amount detector and controller 40, the nitrogen amount detector and controller 50, and the argon amount detector and controller 60 have the same configuration, and the air amount detector and controller 20 is supplied An air quantity detector 21 for detecting the amount of air to be used, an air quantity controller 22 'for converting the deviation between the detected amount from the air quantity detector 21 and a preset value into a current value after PID control; It is comprised by the air volume control valve 23 which adjusts the amount of air supplied according to the electric current value from the air volume control system 22 '.

In addition, the oxygen amount regulator 42 ', the nitrogen amount regulator 52', and the argon amount regulator 62 ', including the air amount regulator 22', include an I / V converter for converting the detected amount into a voltage value, and each corrector ( An adder for adding output values and set values of 120, 140, 150, and 160, a deviation comparator for outputting a deviation between the output value of the I / V converter and an output value of the adder, a PID controller for PID control of the output of the deviation comparator, and the PID A V / I converter converts the output of the controller into a current value and outputs it to each of the control sides 23, 43, 53, and 63.

The automatic control of the oxygen production amount in the oxygen production facility according to the present invention for controlling the oxygen production facility is an increase amount set in advance according to the deviation amount between the amount of oxygen detected by the oxygen amount detection and regulator 40 and a predetermined target amount Or by multiplying the output value of the oxygen production automatic control unit 100 and the preset value with the output of the oxygen production automatic control unit 100 to selectively output the weight loss of the air quantity control system 22 ′ of the air quantity detection and regulator 20. Oxygen amount provided to the adder of the oxygen amount control system 42 'of the oxygen amount detection and regulator 40 by multiplying the air amount corrector 120 provided to the adder and the output value of the oxygen production automatic control unit 100 and a predetermined value. Addition of the nitrogen amount control system 52 'of the nitrogen amount detection and regulator 50 by multiplying the corrector 140 and the output value of the oxygen production automatic control unit 100 and a predetermined value. The nitrogen amount corrector 150 and the output value of the oxygen production automatic control unit 100 are multiplied by a preset value and provided as an adder of the argon amount detector 62 'of the argon amount detector and controller 60. The argon amount corrector 160 is configured.

3 is a detailed configuration diagram of the oxygen production automatic control unit of FIG. 3, referring to FIG. 3, the oxygen production automatic control unit 100 converts a current signal corresponding to the amount of oxygen detected by the oxygen detection and regulator 40 into a voltage. The deviation between the output value of the I / V conversion unit 101, the target value setting unit 102 for setting an oxygen production target amount, and the output value of the I / V conversion unit 101 and the target value of the target value setting unit 102 is determined. According to the output level of the deviation comparator 103 to output, the weight loss setting part 105 which sets the oxygen production weight loss, the increase weight setting part 106 which sets the oxygen production weight increase, and the said deviation comparator 103, It consists of the automatic selection switch 104 which selects the reduction value of the setting part 105 or the increase value of the said increase setting part 106, and outputs it to each corrector.

Figures 4a and 4b is a graph showing the automatic production increase and loss rate according to the present invention, Figures 5a and 5b is a graph showing the purity of the oxygen increase and oxygen reduction according to the present invention.

Operation according to the device of the present invention configured as described above will be described in detail below based on the accompanying drawings.

Referring to Figure 2 to Figure 5, the present invention is to increase or decrease the amount to increase or decrease the amount of input only if you enter the amount to reduce all the processes to operate by the automatic control device When constructing the increase / decrease automatic control system, it is necessary to efficiently manage energy with the optimal control time control.

First, when reducing or increasing the amount of oxygen production, if a desired value is inputted to the target amount setting unit 102 of the oxygen production automatic control unit 100, the value is input to the deviation comparator 103, the oxygen amount detection and regulator 40 The amount of oxygen detected at is converted into a voltage value by the I / V converter 101, wherein the deviation comparator 103 receives the signal of the current oxygen production indicator through the I / V converter 101 The deviation is compared to the value input by the target amount setting unit 102 and the deviation is illustrated in the automatic selection switch 104 which is a HIGH / LOW selection switch.

The automatic selection switch 104 is switched according to the deviation value output from the deviation comparator 103. In this switching operation, when the deviation value is HIGH, the lower high switch is short-circuited and vice versa. In the case of (LOW), the above low switch is short-circuited and the value (reduction value, increase value) already set by the operator is transmitted to the output unit, and this value is transmitted to each controller 22 ', 42', 52 ', 62'. ) Is installed at the front end is input to the compensator (120,140.150,160).

Since the operations of the compensators 120, 140, 150 and 160 are the same, the operation of one compensator will be described. First, the signal output from the oxygen production automatic control unit 100 is received and multiplied by the value set by the operator. To the adders of the controllers 22 '. 42', 52 ', and 62'.

On the other hand, in order for the increase / decrease operation to be started, a start condition must be provided. The start condition is defined as follows.

1. Controller operation mode should be REMOTE setting mode.

2. Deviation between the set value and present value of air intake flow controller, pure nitrogen reflux controller, impurity nitrogen reflux controller, cold chill generation controller, liquid hole liquid level controller, argon inflow controller, oxygen flow controller, nitrogen flow controller, argon flow controller + It should be within 5%, and the present value of the controller should be within the upper and lower limits.

3. Air suction flow regulator upper limit: 180,500 lower limit: 21,000

4. Upper limit of pure nitrogen reflux regulator: 16,150 Lower limit: 1,890

5. Upper limit of impurity nitrogen reflux regulator: 48,600 Lower limit: 6,660

6. Upper limit of chilled water generation controller: 22,560 Lower limit: 14,580

7.Liquid level liquid level controller upper limit: 81 lower limit: 10

8. Crude inflow regulator upper limit: 34,960 lower limit: 3,360

9. Upper limit of oxygen flow controller: 34,200 Lower limit: 4,200

10. Upper limit of nitrogen flow controller: 36,100 Lower limit: 4,200

11.Argon flow regulator upper limit: 990 lower limit: 180

12. The setting value of the increase / decrease setting part is 2.5 NM3 / sec, and the value inputted to the weight reduction setting part is -5 NM3 / second as the standard value.

Here, the set 2.5 NM3 / sec and -5 NM3 / sec are the most efficient values obtained during the PLANT TEST process several times, and the difference between the increase and decrease of the set value is that the increase in weight is caused by the large heat balance during the increase. The difference that occurred.

The calculation formula of the calculator transmitted to each controller is as follows, and the calculation formula performed in each adder of each controller 22 ', 42', 52 ', 62' is represented by the following Equations 1, 2, 3 and 4 Same as

Output = Air-Current setpoint of the flow controller (4) + Emitter output signal x5.55 x 1.00

Output = oxygen ~ current setpoint of the flow controller (1) + emitter output signal x5.55 x 0.18

Nitrogen-flow rate-control system-operand (31)

Output = current setpoint of nitrogen flow regulator (2) + emitter output signal x 5.55 x 0.18

Output = Argon ~ current setpoint of flow controller (3) + emitter output signal x5.55 x 0.01

All of the above equations are KNOW-HOW values obtained by running a test several tens of times with a PLANT with data obtained from the operator's experience based on standard operating values (design values). The flow controllers 22 ', 42', 52 'and 62' receive signals from the compensators 120, 140, 150 and 160 and operate the respective control systems to adjust the flow rate.

When the increase or decrease of the amount of oxygen production is completed, the increase / decrease operation is stopped, and the last set value is held in the controller and the balance of the whole process is broken when an abnormality occurs in any control system during the flow increase / decrease control operation. Therefore, as a supplementary measure, the increase and decrease pause function was added to allow operation.

When the corresponding control system is over, the whole increase / decrease operation is paused. When returning to the limit, the pulse generator generates a pause signal to automatically start the increase / decrease operation. In this case, the pulse generator does not operate when an error occurs.

The LIMIT over calculation formula is shown in Equation 5 below, and the LIMIT value according to each control system is as follows.

Output ~ = ~ 100 / OV ~ RANGE ~ x ~ sq (PV-SP) SUP {2}

* Air suction flow regulator PV RANGE: 200,000 LIMIT: 7%

* Pure nitrogen reflux regulator PV RANGE: 18,000 LIMIT: 5%

* Impurity reflux regulator PV RANGE: 60,000 LIMIT: 5%

* Quantity generation controller PV RANGE: 25,000 LIMIT: 7%

* Liquid level controller PV RANGE: 100 LIMIT: 5%

Crude inflow regulator PV RANGE: 40,800 LIMIT: 6%

* Oxygen Flow Controller PV RANGE: 30,000 LIMIT: 5%

* Nitrogen Flow Controller PV RANGE: 30,000 LIMIT: 5%

* Argon flow regulator PV RANGE: 1,200 LIMIT: 6%

According to the present invention as described above, in the production of oxygen in the oxygen plant, if the production amount is increased or reduced, only the target amount is set automatically, the control system operates automatically to keep the entire process stable while operating. By controlling the control time of the control system, we have secured breakthrough control technology for the operation of the oxygen plant by eliminating the poor purity that occurs during the increase and decrease, temperature and flow hunting, and increasing the output. This contributed to the stable operation, bringing down the oxygen production cost (DOWN).

Claims (1)

An air compressor (10) for supplying compressed air, an air amount detector and controller (20) for detecting the amount of air supplied from the air compressor (10) and adjusting it to a preset value, and from the air compressor (10) An air separator 30 for separating and supplying air into oxygen, nitrogen, and argon, respectively, and an oxygen amount detector and controller for detecting an oxygen amount, a nitrogen amount, and an argon amount of the air separator 30, respectively, and adjusting them to a preset value. (40), an apparatus for controlling an oxygen production facility comprising a nitrogen amount detection and regulator (50) and an argon amount detection and regulator (60); An I / V converter 101 for converting a current signal corresponding to the amount of oxygen detected by the oxygen amount detector and regulator 40 into a voltage, a target value setting unit 102 for setting an oxygen production target amount, and the I / V A deviation comparator 103 for outputting a deviation between the output value of the conversion unit 101 and the target value of the target value setting unit 102, a weight loss setting unit 105 for setting the oxygen production loss, and an oxygen production increase amount According to the output level of the increase setting unit 106 and the deviation comparator 103 to select the reduction value of the weight loss setting unit 105 or the increase value of the increase setting unit 106 to automatically output to each corrector Oxygen production automatic control unit 100 including the selection switch 104; An air amount corrector (120) for multiplying the output value of the oxygen production automatic control unit (100) with a preset value and providing it as an adder of the air amount control system (22 ') of the air amount detection and regulator (20); An oxygen amount corrector 140 which multiplies the output value of the oxygen production automatic controller 100 by a preset value and provides the oxygen amount detector 42 as an adder of the oxygen amount controller 42 ′ of the oxygen amount detector 40; A nitrogen amount corrector 150 which multiplies the output value of the oxygen production automatic control unit 100 with a preset value and provides it as an adder of the nitrogen amount control system 52 'of the nitrogen amount detection and regulator 50; An argon amount corrector 160 which multiplies the output value of the oxygen production automatic control unit 100 with a preset value and provides the argon amount detector and adder of the argon amount controller 62 'of the argon controller 60; Oxygen production automatic control device in the oxygen production facility characterized in that it comprises a.