JP4267902B2 - Operation control device for multiple pump system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention is a multiple pump apparatus in which a plurality of reciprocating pumps having different capacities equipped with a stroke adjusting mechanism are driven by a single electric motor equipped with a rotational speed control mechanism, and a change in required flow rate is achieved. In accordance with the operation of the multiple pump device, the plurality of pumps can be switched smoothly so that accurate injection can be performed.DressIs related to the position.
[0002]
[Prior art]
Natural gas is widely used as a fuel for power generation, and as a fuel in factories and households, but this natural gas is odorless and difficult to detect if leaked. The odorant is injected and mixed, and it is supplied with an odor.
[0003]
As an infusion pump used for injecting an odorant into natural gas, a reciprocating pump of a type that reciprocates a diaphragm has been used conventionally, and the flow rate of natural gas flowing through a gas conduit on the injecting side The stroke width of the diaphragm and the rotation speed of the pump are adjusted in proportion to the above.
[0004]
By the way, when the odor of natural gas is performed, the injection concentration of the odorant relative to the amount of gas sent is 12 to 16 mg / m.³A range of (Normal) / h is desired. On the other hand, the amount of natural gas flowing through the gas conduit is 2700-150,000 m.³The amount of odorant to be injected is required to be adjusted over a wide range from a very small flow rate of 32 to 2400 g / h.
[0005]
As described above, when the ratio between the maximum capacity and the minimum capacity required increases, that is, when the required range ability increases, it becomes difficult to control the flow rate with a single pump. Therefore, conventionally, a plurality of independent reciprocating pumps having different capacities are provided, and a pump having a capacity corresponding to the amount of odorant to be injected is selected from the plurality of pumps having different capacities. It was generally performed to select and operate.
[0006]
Further, in recent years, as schematically shown in FIG. 7, as an example, a plurality of units having different capacities having stroke adjusting mechanisms 4 and 5 such as two reciprocating pumps 2 having a large capacity and a small capacity are provided. 3 is installed on the same bed (not shown), and the pumps 2 and 3 are connected to one electric motor 6 equipped with an inverter 7 as a rotation speed control mechanism so as to be drivable together. It has also been proposed to use the pump device 1. That is, this connects the discharge side of the multiple pump device 1 through the odorant supply pipe 11 in the middle of the natural gas 9 circulation gas conduit 10 to which the odorant 8 is injected, An odorant suction pipe 12 for guiding the odorant 8 from an odorant tank (not shown) is connected to the suction side of the multiple pump device 1, and the flow rate of the natural gas 9 flowing through the gas conduit 10 is connected. When the flow rate of the odorant 8 to be injected is determined, the small-capacity pump 3 and the large-capacity pump 2 of the multiple pump device 1 correspond to the required flow rate of the odorant 8. The odorant 8 having a flow rate corresponding to the required flow rate is discharged by switching the operation of either one of the pumps 2 or 3 with the electric motor 6 so as to share the flow ranges different in size. It will be injected into the gas conduit 10 through the odorant supply pipe 11 Are to.
[0007]
When the natural gas 9 is circulated through the gas conduit 10, the pressure in the gas conduit 10 may fluctuate in the range of 3.5 to 4.5 MPa.
[0008]
As another example of the multiple pumps, a plurality of reciprocating pumps that can individually adjust the plunger stroke are connected to a single variable speed motor via a shaft. Varying the supply ratio of the main agent and each accelerator supplied from each of the above reciprocating pumps when injecting into the ground while preparing a chemical grout agent for ground injection by supplying the main agent and a plurality of accelerators simultaneously Thus, there has been conventionally proposed a method in which the mixing ratio of each component chemical solution can be changed in accordance with the ground properties to be injected (see, for example, Patent Document 1).
[0009]
[Patent Document 1]
JP-A-54-99309
[0010]
[Problems to be solved by the invention]
However, in order to improve rangeability, when installing a plurality of independent pumps having different capacities, it is necessary to install a plurality of motors because each of the pumps requires a driving motor. Since multiple inverters, which are mechanisms for controlling the number of revolutions, are required for each motor, it is necessary to install multiple inverters. These multiple motors and inverters increase equipment costs and require a large installation space. Furthermore, there is a problem that incidental facilities such as piping and electrical facilities increase.
[0011]
On the other hand, when the multiple pump device 1 as shown in FIG. 7 is used, only one motor 6 or inverter 7 should be installed. When switching between the large-capacity pump 2 and the small-capacity pump 3 in order to share them, according to the performance test of the pumps 2 and 3, the motor 6 according to the required flow rate of the odorant 8 is proposed. , The pump 2 or 3 driven by the electric motor 6, and the pump stroke of the pump 2 or 3 are uniquely determined. Therefore, the required flow rate of the odorant 8 is the same as that of the pump 2. 3, even if the change in the required flow rate of the odorant 8 is slight, the rotational speed of the motor 6 and the pumps 2 and 3 are transiently changed. Need to respond by changing the pump stroke suddenly Resulting that there is, for this purpose, the required flow rate of the odorant 8, there is a problem that there is a possibility that cause significant deviations in the actual supply rate to the gas conduit 10 to be injected destination.
[0012]
Furthermore, the capacity of the positive displacement pumps such as the pumps 2 and 3 changes due to the change of the pressure on the discharge side. Therefore, in the case where the pressure in the gas conduit 10 serving as the injection destination varies greatly, Even if the pumps 2 and 3 of the multiple pump device 1 are driven by the electric motor 6 having a prescribed rotational speed and the pump strokes of the pumps 2 and 3 are adjusted as prescribed, There is also a problem in that the desired flow rate of the agent 8 cannot be obtained accurately, and there is a possibility that the required flow rate of the odorant 8 and the supply flow rate are significantly different.
[0013]
In addition, what was disclosed by the said patent document 1 was made to be able to change a supply ratio for every said reciprocating pump, when supplying a respectively different chemical | medical agent from the several reciprocating pump in a multiple pump. However, the large rangeability required when the odorant 8 is supplied to the natural gas 9 flowing through the gas conduit 10 cannot be achieved.
[0014]
  Accordingly, the present invention provides a multiple pump apparatus comprising a plurality of pumps having different capacities that are drivably connected to a single electric motor in order to expand the range ability. Therefore, it is possible to supply the fluid in an accurate amount according to the required flow rate, and to achieve the required flow rate regardless of the pressure fluctuation of the injection destination. Multiple pump system operating system that can supply the correct amount of fluidDressIs intended to provide a place.
[0015]
[Means for Solving the Problems]
  In order to solve the above problems, the present invention provides a plurality of reciprocating pumps each having a stroke adjusting mechanism and having different capacities, and a single electric motor having a rotation speed control mechanism.soMultiple-type pump device designed to be drivenA fluid ratio setting device for determining a required amount of fluid to be injected by the fluid ratio setting device, inputting the requested fluid amount determined by the fluid ratio setting device, Pump deviceAdjustment mechanism of each reciprocating pump in the aboveNisoIn addition to giving a stroke control command to each, a rotation speed control mechanism for the motorOutForce control command is given, andInput from the fluid ratio setterWhen switching between reciprocating pumps with different capacities according to the required amount of fluid to be injected, when the required amount tends to increase, the pump with the smaller capacity is switched to the pump with the larger capacity. Switch operationFlow rate setting valueThan when the required volume is decreasing, the operation is switched from the larger capacity pump to the smaller capacity pump.Flow rate setting valueIs smallerThe point where the operation of the reciprocating pump should be switched is shifted so thatAn operation control device for a multiple pump device having a configuration including a control device is provided.
[0016]
When the required amount of fluid to be injected increases and increases to a predetermined flow rate setting value for pump switching when the required fluid amount tends to increase, the operation is switched from the smaller capacity pump to the larger capacity pump. . Once the pump with the smaller capacity is switched to the pump with the larger capacity in this way, even if the fluid demand fluctuates in the vicinity of the flow rate set value and slightly falls below the flow rate set value, the capacity The large-side pump is continuously driven, and the operation of the large-capacity pump is performed when the fluid demand is set to a value smaller than the flow rate setting value and the fluid demand is decreasing. It is maintained until it is reduced to a predetermined flow rate setting value for switching.
[0017]
On the other hand, when the required amount of fluid to be injected decreases and decreases to a predetermined flow rate setting value for pump switching when the required amount of fluid tends to decrease, operation from the larger capacity pump to the smaller capacity pump is performed. Once the operation is switched to the pump with the smaller capacity in this way, the required fluid amount fluctuates in the vicinity of a predetermined flow rate setting value for pump switching when the required fluid amount tends to decrease, and the flow rate Even if the set value is slightly exceeded, the pump with the smaller capacity is continuously driven. The operation of the pump with the smaller capacity is for switching the pump when the fluid demand is decreasing. The flow rate is maintained until it increases to a predetermined flow rate setting value for switching the pump when the required fluid flow rate tends to increase.
[0018]
  Furthermore, the discharge side of the multiple pump systemA pressure gauge that detects the discharge side pressure of the multiple pump device is installed in the fluid supply pipe connected to the pipe, and the detected value of the pressure gauge is input.Pressure correction command to control deviceWith a pressure controller that emits,By adopting a configuration in which pressure correction is performed on the required amount of fluid to be injected in consideration of the change in capacity of the positive displacement pump due to the change in the discharge side pressure of the multiple pump device, the positive displacement pump The capacity control of each pump can be accurately performed, and the influence of fluctuations in the discharge side pressure of the multiple pump device can be reduced.
[0019]
  Furthermore, the multiple pump deviceofvomitThe fluid supply pipe connected to the side is injected from the multiple pump device through the fluid supply pipeFlow meter for measuring fluid flow rateInstall the flow meterDepending on the detected valueInput from the fluid ratio setter to the controllerA flow control mechanism to correct the required amount of fluid, Provided between the fluid ratio setting device and the control deviceWith this configuration, the fluid discharge amount from the multiple pump device is fed back to correct the required fluid amount, so that feedback flow rate control can be performed and the fluid supply amount can be reduced. It becomes possible to control with higher accuracy.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0021]
  1 to 3 (a) and 3 (b) show the operation control of the multiple pump device of the present invention.DressAs an embodiment of the apparatus, a case where the present invention is applied to a multiple pump apparatus that supplies odorant to natural gas is shown, and the gas conduit 10 is circulated in the same configuration as that shown in FIG. The required amount F of the odorant 8 to be injected into the gas conduit 10 based on the flow rate of the natural gas 9 and the desired odorant concentration₀The odorant ratio setting device 13 for determining the odorant and the odorant requirement amount F determined by the odorant ratio setting device 13 is provided.₀EnterShi, Odorant requirement amount F₀Accordingly, the stroke control command C is sent to the stroke adjusting mechanisms 4 and 5 of the reciprocating pumps 2 and 3 of the multiple pump device 1 respectively._S1And C_S2IssueAndOutput control command C to the inverter 7 to control the rotation speed of the motor 6_PThe control device 14 includes a one-input three-output control device 14 that emits the odorant request amount F input from the odor ratio setting device 13.₀The mode is switched according to whether the amount is increasing or decreasing, and the required amount of odorant F₀The odorant requirement amount F is more than the flow rate set value for switching the operation from the small capacity pump 3 to the large capacity pump 2 when the trend is increasing.₀The odorant requirement amount F is set so that the flow rate setting value for switching the operation from the large-capacity pump 2 to the small-capacity pump 3 becomes smaller when the trend is decreasing.₀The point at which the operation of the large-capacity pump 2 and the small-capacity pump 3 should be switched according to the change of the odorant requirement amount F₀It can be shifted between the time of increasing trend and the tendency of decreasing trend.
[0022]
This will be described in detail below. The required amount of odorant F determined by the odor ratio setting device 13 is described above.₀, For example, varies in the range of 0 to 3000 ml / h. Accordingly, the small capacity pump 3 in the multiple pump device 1 has a capacity of 0 to 450 ml / h as shown in FIG. The large capacity pump 2 can cover the range of 350 to 3000 ml / h as shown in FIG.
[0023]
The control device 14 receives the odorant request amount F input from the odor ratio setting device 13.₀In order to determine whether or not the odor is increasing or decreasing, the odorant request amount F from the odor ratio setting device 13 is determined.₀Is input when the odorant request amount F is input.₀When the value increases from 0 to 450 ml / h or more, a signal 17a of “1” is output, while the required amount of odorant F₀Once the amount reaches 450 ml / h or more, the required amount of odorant F₀A mode setting unit 15 having a latch relay 18 is formed and provided on the downstream side of the monitor switch 16 that outputs a “0” signal 17b when the voltage decreases to 350 ml / h or less. Odorant requirement amount F input from odor ratio setter 13₀Is increasing from 0, it becomes “0” until it reaches 450 ml / h, and then the required amount of odorant F₀Increases to 450 ml / h or more, it becomes “1”, while the required amount of odorant F₀Is in a decreasing tendency from a large value of 450 ml / h, the odorant requirement amount F₀Is “1” while the value is greater than 350 ml / h, and then the required odorant F₀Is reduced to 350 ml / h or less, a signal 19 that becomes “0” is output from the latch relay 18, and the AND circuit 21 in the stroke control unit 20 for the small-capacity pump 3 described later, and the large-capacity pump 2 Input to the NOT circuit 23 in the stroke control unit 22 and the NOT circuit 25 in the output control unit 24 of the inverter 7 is possible.
[0024]
The small-capacity pump stroke control unit 20 receives the odorant request amount F inputted from the odor ratio setting device 13.₀In response to the function F as shown in FIG._X1The first function generator 27 for outputting the stroke set value 26 of the small capacity pump 3 based on the₀Is greater than 350 ml / h, the monitor switch 29 is configured to emit a signal 28 of “1”, the signal 28 output from the monitor switch 29, and the latch relay 18 of the mode setting unit 15. An AND circuit 21 that outputs a switching signal 30 of “1” only when both of the signals 19 are “1”, and when the switching signal 30 input from the AND circuit 21 is “0”, it switches to the reset side b1. The stroke set value 26 output from the first function generator 27 is directly used as the stroke control command C._S2Is output to the small-capacity pump 3, and when the switching signal 30 which is “1” is input from the AND circuit 21, the switching is made to the set side a 1, and the 0% signal 32 generated by the signal generator 31 is stroked. Control command C_S2It is set as the structure provided with the switch 33 which outputs to the small capacity pump 3 as.
[0025]
The large-capacity pump stroke controller 22 receives the odorant request amount F input from the odor ratio setting device 13.₀In response to the function F as shown in FIG._X2The second function generator 35 for outputting the stroke set value 34 of the large-capacity pump 2 based on the odorant request amount F₀When the signal becomes less than 450 ml / h, a monitor switch 37 that generates a signal 36 of “1” and a signal 19 output from the latch relay 18 of the mode setting unit 15 are input and an inverted signal of the signal 19 A switching signal 39 of “1” is output only when both the NOT circuit 23 outputting 38 and the inverted signal 38 output from the NOT circuit 23 and the signal 36 output from the monitor switch 37 are “1”. When the AND circuit 40 and the switching signal 39 input from the AND circuit 40 are “0”, the circuit is switched to the reset side b2, and the stroke setting value 34 output from the second function generator 35 is used as it is as a stroke control command. C_S1Is output to the large-capacity pump 2, and when the switching signal 39 that is “1” is input from the AND circuit 40, the switching is made to the set side a 2, and the 0% signal 42 generated by the signal generator 41 is stroked. Control command C_S1It is set as the structure provided with the switching device 43 output to the large capacity pump 2 as.
[0026]
The inverter output control unit 24 receives the odorant request amount F input from the odor ratio setting device 13.₀In accordance with the function F as shown in FIG._X3The third function generator 45 for outputting the output set value 44 of the inverter 7 based on the odorant request amount F₀When the signal becomes 350 ml / h or more, a monitor switch 48 that generates a signal 46 of “1”, a signal 19 output from the latch relay 18 of the mode setting unit 15, and an inverted signal 48 of the signal 19 are input. A switch signal 49 of “1” is output only when both the NOT circuit 25 that outputs “1” and the inverted signal 48 output from the NOT circuit 25 and the signal 46 output from the monitor switch 47 are “1”. When the AND circuit 50 and the switching signal 49 input from the AND circuit 50 are “0”, the circuit is switched to the reset side b3, and the inverter output set value 44 output from the third function generator 45 is directly used as the output control command. C_PWhen the switching signal 49 that is “1” is input from the AND circuit 50, the signal is switched to the set side a3, and the 60 Hz signal 52 generated by the signal generator 50 is output as an output control command. C_PAs a configuration including a switch 53 for outputting to the inverter 7.
[0027]
54, 55, and 56 are all restrictors. The switches 33 and 43 of the stroke control units 20 and 22 are connected to the corresponding pumps 3 and 2 or the switch 53 of the inverter output control unit 24. Thus, an excessive output is not made to the inverter 7.
[0028]
Here, the operation of the control device 14 will be described. First, the odorant 8 determined by the odor ratio setting unit 13 as the amount of the natural gas 9 flowing through the gas conduit 10 increases. Requested amount F₀Is in a tendency to gradually increase from 0, the required amount of odorant F₀Is between 0 and 350 ml / h, the signal 19 output from the latch relay 18 is “0”. For this reason, the small capacity pump stroke control unit 20 outputs a switching signal 30 which is “0” from the AND circuit 21. For this reason, in the switching unit 33, the stroke set by the first function generator 27 on the reset side b 1. The set value 26 is the same as the stroke control command C._S2Is output to the small capacity pump 3.
[0029]
During this time, in the large-capacity pump stroke control unit 22, a signal 36 that is “1” is output from the monitor switch 37, and at the same time, an inverted signal 38 of the signal 19 input from the latch relay 18 from the NOT circuit 23. Since “1” is output and these signals are input to the AND circuit 40, a switching signal 39 that is “1” is generated from the AND circuit 40 and is input to the switch 43. The device 43 is switched to the set side a2, and the 0% signal 42 from the signal generator 41 is changed to the stroke control command C._S1Is output to the large-capacity pump 2.
[0030]
At this time, since the signal output from the monitor switch 47 is “0” in the inverter output control unit 24, the switching signal 49 output from the AND circuit 50 is “0”. The inverter output set value 44 set by the third function generator 45 on the side b3 is the output control command C_PAnd output to the inverter 7.
[0031]
As a result, the required amount of odorant F₀Is increased between 0 and 350 ml / h, the stroke of the small capacity pump 3 is controlled according to the stroke set value 26 set by the first function generator 27 as shown by the solid line in FIG. At the same time, the output of the inverter 7 is controlled in accordance with the inverter output set value 44 set by the third function generator 45 as shown by a two-dot chain line in FIG. By controlling, the odorant requirement amount F₀The amount of the odorant 8 corresponding to the above is sent from the small capacity pump 3 and injected into the natural gas 9 flowing through the gas conduit 10. During this time, the large-capacity pump 2 has a function F shown in FIG._X2As is apparent from the stroke setting value 34 based on
[0032]
Next, odorant requirement F₀Is increased from 350 to 450 ml / h, the signal 19 output from the latch relay 18 is “0”. For this reason, since the AND circuit 21 of the small-capacity pump stroke control unit 20 continues to output the switching signal 30 that is “0”, the switching device 33 supplies the first function generator 27 on the reset side b1. The stroke set value 26 set by the_S2Is output to the small capacity pump 3.
[0033]
At this time, the large-capacity pump stroke control unit 22 continuously outputs the signal 36 which is “1” from the monitor switch 37, and the inverted signal 38 of the signal 19 input from the latch relay 18 in the NOT circuit 23 is Since the signal is continuously output as “1”, the AND circuit 40 continuously outputs the switching signal 39 that is “1”. Therefore, the switch 43 continues to output the 0% signal 42 on the set side a2. Is the stroke control command C_S1Is output to the large-capacity pump 2.
[0034]
At this time, the inverter output control unit 24 switches the signal 46 output from the monitor switch 47 to “1”, and the NOT circuit 25 outputs “1” as the inverted signal 48 of the signal 19 of the latch relay 18. For this reason, the switching signal 49 output from the AND circuit 50 is switched to “1”. Therefore, the switching unit 53 is switched to the set side a 3, and the signal generator 51 generates the switching unit 53. 60 Hz signal 52 is output control command C_PAs output to the inverter 7.
[0035]
As a result, the required amount of odorant F₀Is increased from 350 to 450 ml / h, the state where the output of the inverter 7 is kept constant at 60 Hz and the rotational speed of the motor 6 is kept constant, as shown by a two-dot chain line in FIG. Thus, as shown by a solid line in FIG. 3 (a), the stroke of the small-capacity pump 3 is controlled so as to be increased according to the stroke set value 26 set by the first function generator 27. Deodorant requirement F₀The amount of the odorant 8 corresponding to the above is sent from the small capacity pump 3 and injected into the natural gas 9 flowing through the gas conduit 10. During this time, the large-capacity pump 2 is not operated because the stroke is always controlled to 0%, as shown by the one-dot chain line in FIG.
[0036]
Next, required amount of odorant F₀Is increased beyond 450 ml / h, the signal 19 output from the latch relay 18 is switched to “1”. Therefore, the AND circuit 21 of the small-capacity pump stroke control unit 20 receives the signal 28 that is “1” output from the monitor switch 29 and the signal 19 that is “1” from the latch relay 18. Thus, the switching signal 30 output from the AND circuit 21 becomes “1”, whereby the switching device 33 is switched to the set side a1, and the 0% signal 32 emitted from the signal generator 31 is the stroke control. Command C_S2Is output to the small capacity pump 3.
[0037]
At this time, in the large-capacity pump stroke control unit 22, the signal 36 output from the monitor switch 37 is switched to “0” and the inverted signal 38 of the signal 19 of the latch relay 18 output from the NOT circuit 23 is “0”. Therefore, the switching signal 39 output from the AND circuit 40 becomes “0”, so that in the switch 43, the stroke set value 34 set by the second function generator 35 on the reset side b 2 remains as it is. Stroke control command C_S1Is output to the large-capacity pump 2.
[0038]
At this time, in the inverter output control unit 24, the signal output from the monitor switch 47 remains “1”, but the inverted signal 48 of the signal 19 of the latch relay 18 output from the NOT circuit 25 is “0”. Therefore, the switching signal 49 output from the AND circuit 50 becomes “0”, so that the switching unit 53 is switched to the reset side b3 again. Therefore, the switching unit 53 generates a third function. The inverter output set value 44 set by the controller 45 is the output control command C_PAs output to the inverter 7.
[0039]
As a result, the required amount of odorant F₀Is increased from 450 ml / h to 3000 ml / h, the stroke of the large-capacity pump 2 is set to the stroke set value 34 set by the second function generator 35, as shown by the one-dot chain line in FIG. The output of the inverter 7 is controlled according to the inverter output set value 44 set by the third function generator 45 as indicated by a two-dot chain line in FIG. By controlling the rotation speed, the required amount of odorant F₀The amount of the odorant 8 corresponding to the above is sent from the large-capacity pump 2 and injected into the natural gas 9 flowing through the gas conduit 10. At this time, the small-capacity pump 3 has a function F shown in FIG._X1As is apparent from the stroke setting value 26 based on
[0040]
Therefore, odorant requirement amount F₀Is increasing, the odorant requirement amount F₀The operation switching from the small-capacity pump 3 to the large-capacity pump 2 performed in response to the increase in the flow rate is performed when 450 ml / h is reached.
[0041]
On the other hand, odorant requirement amount F₀Is in a decreasing trend, the required amount of odorant F₀Is in the range of 3000 to 450 ml / h, the odorant requirement amount F described above₀And the odorant requirement amount F₀As in the case where is in the range of 450 ml / h or more, the latch relay 18 outputs a signal 19 that is “1”. Therefore, the AND circuit 21 of the small-capacity pump stroke control unit 20 receives the signal 28 that is “1” output from the monitor switch 29 and the signal 19 that is “1” from the latch relay 18. Therefore, a switching signal 30 that is “1” is output from the AND circuit 21, whereby the switching device 33 is switched to the set side a 1, and the 0% signal 32 generated from the signal generator 31 is Stroke control command C_S2Is output to the small capacity pump 3.
[0042]
At this time, in the large-capacity pump stroke control unit 22, the signal 36 output from the monitor switch 37 becomes “0”, and the inverted signal 38 of the signal 19 of the latch relay 18 output from the NOT circuit 23 is “0”. Therefore, the switching signal 39 output from the AND circuit 40 is “0”, so that in the switching device 43, the stroke setting value 34 set by the second function generator 35 on the reset side b2 remains as it is. Stroke control command C_S1Is output to the large-capacity pump 2.
[0043]
At this time, in the inverter output control unit 24, the signal 46 output from the monitor switch 47 is “1”, but the inverted signal 48 of the signal 19 of the latch relay 18 output from the NOT circuit 25 is “0”. Therefore, the switching signal 49 output from the AND circuit 50 is “0”. Therefore, in the switching device 53, the inverter output setting value 44 set by the third function generator 45 on the reset side b3 is the output control command C._PAs output to the inverter 7.
[0044]
As a result, the required amount of odorant F₀Is reduced from 3000 ml / h to 450 ml / h, the stroke of the large-capacity pump 2 depends on the stroke set value 34 set by the second function generator 35 as shown by the one-dot chain line in FIG. In addition to being controlled, the output of the inverter 7 is controlled according to the inverter output set value 44 set by the third function generator 45 as shown by a two-dot chain line in FIG. Is controlled, the odorant requirement amount F₀The amount of the odorant 8 corresponding to the above is sent from the large-capacity pump 2 and injected into the natural gas 9 flowing through the gas conduit 10. At this time, the small-capacity pump 3 has a function F shown in FIG._X1As is apparent from the stroke setting value 26 based on
[0045]
Next, odorant requirement F₀Is reduced to 450 to 350 ml / h, the signal 19 output from the latch relay 18 continues to be “1”. For this reason, the AND circuit 21 of the small-capacity pump stroke control unit 20 receives the signal 19 that is “1” from the latch relay 18 and the signal that is continuously “1” from the monitor switch 29. The AND circuit 21 continues to output a switching signal 30 which is “1”. Therefore, in the switch 33, the 0% signal 32 on the set side a1 continues to be the stroke control command C._S2Is output to the small capacity pump 3.
[0046]
At this time, in the large-capacity pump stroke control unit 22, the signal 36 output from the monitor switch 37 is switched to “1”, but from the NOT circuit 23, the inverted signal 38 of the signal 19 input from the latch relay 18 is “0”. ”Is continuously output, and the AND circuit 40 continuously outputs the switching signal 39 which is“ 0 ”. Therefore, the switching device 43 continues to output the second function generator 35 on the reset side b2. The set stroke set value 34 continues to be the stroke control command C_S1Is output to the large-capacity pump 2.
[0047]
At this time, in the inverter output control unit 24, the signal 46 output from the monitor switch 47 remains “1”, and the NOT circuit 25 continues to output “0” as the inverted signal 48 of the signal 19 of the latch relay 18. ”Is output, the switching signal 49 output from the AND circuit 50 continues to be“ 0 ”. Therefore, in the switching device 53, the inverter output set value set by the third function generator 45 on the reset side b3. 44 is an output control command C_PAs output to the inverter 7.
[0048]
As a result, the required amount of odorant F₀Is reduced at 450 to 350 ml / h, the stroke of the large-capacity pump 2 is controlled in accordance with the stroke set value 34 set by the second function generator 35, as shown by the one-dot chain line in FIG. In this state, the output of the inverter 7 is controlled according to the inverter output set value 44 set by the third function generator 45, and the rotational speed of the motor 6 is controlled. F₀The amount of the odorant 8 corresponding to the above is sent from the large-capacity pump 2 and injected into the natural gas 9 flowing through the gas conduit 10. At this time, the small capacity pump 2 is not operated because the stroke is controlled to 0% as shown by the solid line in FIG.
[0049]
Furthermore, odorant requirement amount F₀Decreases from 350 ml / h, the signal 19 output from the latch relay 18 is switched to “0”. In the small capacity pump stroke control unit 20, the signal 28 output from the monitor switch 29 is switched to “0”, and the signal 19 input from the latch relay 18 is also switched to “0”. The switching signal 30 is switched to “0”. Therefore, the switching unit 33 is switched to the reset side b1, and the stroke set value 26 set by the first function generator 27 remains as it is as the stroke control command C._S2Is output to the small capacity pump 3.
[0050]
At this time, in the large-capacity pump stroke control unit 22, a signal 36 that is “1” is output from the monitor switch 37, and at the same time, an inverted signal 38 of the signal 19 of the latch relay 18 output from the NOT circuit 23 is “ In order to switch to “1”, the AND circuit 40 issues a switching signal 39 which becomes “1”, whereby the switching device 43 is switched to the set side a2, and the 0% signal 42 from the signal generator 41 is stroked. Control command C_S1Is output to the large-capacity pump 2.
[0051]
At this time, in the inverter output control unit 24, the inverted signal 48 of the signal 19 of the latch relay 18 output from the NOT circuit 25 is switched to “1”, but the signal 46 output from the monitor switch 47 is set to “0”. Since the switching is performed, the switching signal 49 output from the AND circuit 50 continues to be “0”. Therefore, the switching unit 53 outputs the inverter output set value 44 set by the third function generator 45 on the reset side b3 as it is. Control command C_PAnd output to the inverter 7.
[0052]
As a result, the required amount of odorant F₀Is reduced between 350 and 0 ml / h, the stroke of the small capacity pump 3 is controlled according to the stroke set value 26 set by the first function generator 27 as shown by the solid line in FIG. At the same time, the output of the inverter 7 is controlled according to the inverter output set value 44 set by the third function generator 45 as shown by a two-dot chain line in FIG. By controlling, the odorant requirement amount F₀The amount of the odorant 8 corresponding to the above is sent from the small capacity pump 3 and injected into the natural gas 9 flowing through the gas conduit 10. During this time, the large-capacity pump 2 has a function F shown in FIG._X2As is apparent from the stroke setting value 34 based on
[0053]
Therefore, odorant requirement amount F₀Is in a decreasing trend, the required amount of odorant F₀Switching from large capacity pump 2 to small capacity pump 3 due to the decrease in₀Will be carried out at the time when the pressure is reduced to 350 ml / h.
[0054]
In addition, in a positive displacement pump, the pump displacement changes with the pressure fluctuation on the discharge side. In order to prevent the change in the discharge amount, the one shown in FIGS. 1 to 3 (A) and (B) is another embodiment of the present invention. A pressure gauge 57 for detecting the discharge-side pressure of the multiple pump device 1 is installed at an intermediate position of the odorant supply pipe 11, and the detected value P of the pressure gauge 57 is inputted to the control device 14. A pressure controller 58 that issues a pressure correction command Cr to the control device 14, and the controller 14 receives an odorant request amount input from the odor ratio setting device 13 based on the pressure correction command Cr from the pressure controller 58. F₀Is provided with a calculator 59 (FIG. 2) that corrects the odorant, and the calculator 59 inputs the odorant request amount F that is input from the odor ratio setting unit 13 to the control device 14.₀On the other hand, based on the pressure correction command Cr from the pressure controller 58, the required amount of odorant F in consideration of the change in the capacity of each pump 2, 3 accompanying the change in the discharge side pressure of the multiple pump device 1₀The required amount of odorant F after the pressure correction₀Based on the above, the stroke control of the large-capacity pump 2 and the small-capacity pump 3 in the stroke control units 20 and 22 and the output control of the inverter 7 in the inverter output control unit 24 are performed.
[0055]
Furthermore, the required amount of odorant F determined by the odor ratio setting device 13₀Can be accurately satisfied by the flow rate of the odorant 8 injected from the multiple pump apparatus 1 through the odorant supply pipe 11 into the gas conduit 10, A flow meter 60 is provided at an intermediate position, and a detected value F of the flow meter 60 is provided between the odor ratio setting device 13 and the control device 14.₁Odorant request amount F input to the control device 14 from the odor ratio setting device 13₀It is assumed that an arithmetic unit 61 is provided as a flow rate control mechanism for correcting the above.
[0056]
Incidentally, 62 is an odorant return line with a pressure regulating valve 63 provided by branching from the odorant supply pipe 11, and when the discharge pressure of the multiple pump device 1 becomes excessive, for example, By causing the pressure controller 58 to control the opening degree of the pressure regulating valve 63, by returning a part of the discharged odorant 8 to the odorant tank (not shown) through the odorant return line 62, The discharge side pressure of the multiple pump device 1 can be reduced.
[0057]
  Operation control of the above-described multiple pump device of the present inventionDressAccording to the setting, the required amount of odorant F₀Is increasing, the operation switching from the small-capacity pump 3 to the large-capacity pump 2 of the multiple pump device 1 is performed when the capacity reaches 450 ml / h, while the required odorant amount F₀Is in a decreasing trend, the operation switching from the large-capacity pump 2 to the small-capacity pump 3 can be performed when the operation is decreased to 350 ml / h. Odorant requirement amount F₀Once the operation is switched from the small capacity pump 3 to the large capacity pump 2 by exceeding 450 ml / h under an increasing trend, then the odorant requirement amount F₀Even if the value fluctuates in the vicinity of 450 ml / h and falls below 450 ml / h with this fluctuation, the switching from the large-capacity pump 2 to the small-capacity pump 3 is not immediately performed, and thereafter 350 ml / h The large capacity pump will continue to operate as long as it does not decrease. Conversely, odorant requirement amount F₀Once the operation is switched from the large capacity pump 2 to the small capacity pump 3 due to the decrease of 350 ml / h under a decreasing trend, then the odorant requirement amount F₀Even if fluctuates up and down at 350 ml / h, switching from the small-capacity pump 3 to the large-capacity pump 2 is not performed immediately, and the small-capacity pump 3 is continuously operated unless it increases to 450 ml / h. The hysteresis can be given to the switching point of each pump 2 and 3, and the required amount of odorant F₀Even if it is necessary to control at around 350 ml / h or around 450 ml / h, there is no possibility that the rotational speed of the electric motor 6 or the pump strokes of the pumps 2 and 3 will change suddenly. Therefore, the influence of disturbance can be kept small, and the required amount of odorant F₀However, the required amount of odorant F is set in any part of the wide range ability combining the capacity ranges of the pumps 2 and 3 of the multiple pump device 1.₀It becomes possible to discharge the odorant 8 accurately so as to satisfy the above.
[0058]
Therefore, using the pump motor of the existing equipment, a small pump is added to the motor to form the multiple pump device 1, and the multiple pump device 1 of the present invention is added to the multiple pump device 1. By applying this control method and apparatus, it is possible to obtain a pump that satisfies a wide range ability without adding electric equipment or piping.
[0059]
Further, by using a general-purpose programmable controller as the control device 14, it becomes possible to individually set performance curves unique to the pumps 2 and 3, and proper operation can be maintained.
[0060]
Further, the fluctuation amount of the discharge side pressure of the multiple pump device 1 is detected, and the required amount of odorant input from the odor ratio setting device 13 to the control device 14 by the pressure correction command Cr based on the detected pressure value P. F₀Therefore, the displacement control of the large-capacity pump 2 and the small-capacity pump 3 that are positive displacement pumps can be accurately performed, and the influence of fluctuations in the discharge-side pressure can be reduced.
[0061]
Further, the amount of odorant 8 output from the odor ratio setting device 13 by feeding back the discharge amount of the odorant 8 from the multiple pump device 1 is fed back.₀Therefore, it is possible to perform feedback flow rate control and to inject the odorant 8 with higher accuracy.
[0062]
Next, FIGS. 4 to 6 (A) and (B) show still another embodiment of the present invention. In the same configuration as that shown in FIGS. As with the large-capacity pump 2 and the small-capacity pump 3 of the pump device 1, the required odorant F₀In addition to the medium-capacity pump 2a and the small-capacity pump 3a having a flow rate set at a set value as shown in FIGS. 5 (a) and 5 (b), respectively, a larger capacity, for example, As shown in FIG. 5 (c), a case where the present invention is applied to operation control of a multiple pump apparatus 1a including a pump 64 with a stroke adjusting mechanism 65 capable of covering a capacity range of 2200 to 6000 ml / h is shown. The required odorant amount F determined by the odor ratio setting device 13₀In the case of increasing, the flow rate setting value (450 ml / h) for switching from the operation state (solid line) of the small capacity pump 3a as shown in FIG. 6 (a) to the operation of the medium capacity pump 2a (dashed line) As shown in FIG. 6 (b), the odor is applied rather than the flow rate setting value (3000ml / h) for switching from the operation state (dashed line) of the medium capacity pump 2a to the operation of the large capacity pump 64 (dashed line). Agent requirement F₀, The flow rate setting value (350 ml / h) for switching from the operation state (one-dot chain line) of the medium capacity pump 2a to the operation (solid line) of the small capacity pump 3a, and the large capacity pump 64 A control device 14a for controlling the flow rate setting value (2200 ml / h) for switching from the operation state (broken line) to the operation (one-dot chain line) of the medium capacity pump 2a is provided, and the small capacity pump is provided. Hysteresis is given to the switching point between 3a and medium capacity pump 2a, and hysteresis can be given to the switching point between medium capacity pump 2a and large capacity pump 64. 6A and 6B, the alternate long and two short dashes line indicates the inverter output setting curve.
[0063]
4 that are the same as those shown in FIG. 1 are denoted by the same reference numerals.
[0064]
According to the present embodiment, the required amount of odorant F₀When the odorant supply amount is controlled in the vicinity of the point where the operation of the small-capacity pump 3a and the medium-capacity pump 2a is switched to satisfy the condition, the odorant supply is performed near the operation switching point of the medium-capacity pump 2a and the large-capacity pump 64 Even in the case of controlling the amount, there is no possibility that the rotational speed of the electric motor 6 and the pump stroke will change suddenly, so that it can be obtained by combining the capacities of the large, medium and small pumps 64, 2a and 3a. In any part of the expanded range ability, the odorant requirement amount F can be reduced while minimizing the influence of disturbance.₀The odorant 8 can be discharged accurately to satisfy the above.
[0065]
In addition, this invention is not limited only to the said embodiment, odorant request amount F₀Odorant requirement amount F than the flow rate set value when switching from a smaller capacity pump to a larger capacity pump₀If the flow rate setting value for switching from the pump with the larger capacity to the pump with the smaller capacity is made smaller when there is a tendency to decrease, the flow shown in FIGS. Points for switching the operation between the small capacity pump 3 and the large capacity pump 2 in the embodiment, and the small capacity pump 3a and the medium capacity pump 2a in the embodiments of FIGS. The point at which the operation of the medium capacity pump 2a and the large capacity pump 64 is switched may be freely set according to the capacity range that can be covered by the pump to be used, and the multiple pump devices 1, 1a. For example, the present invention may be applied to a chemical other than the odorant used for injecting a chemical other than the gas conduit 10 into a required portion, and the present invention is a multi-unit equipped with four or more pumps having different capacities. Also for the pump Can be use, other, it can of course be modified in various ways without departing from the gist of the present invention.
[0066]
【The invention's effect】
  As described above, according to the present invention, the following excellent effects are exhibited.
(1) One reciprocating pump with different capacities equipped with individual stroke adjustment mechanisms and one motor equipped with a rotation speed control mechanismsoMultiple-type pump device designed to be drivenA fluid ratio setting device for determining a required amount of fluid to be injected by the fluid ratio setting device, inputting the requested fluid amount determined by the fluid ratio setting device, Pump deviceAdjustment mechanism of each reciprocating pump in the aboveNisoIn addition to giving a stroke control command to each, a rotation speed control mechanism for the motorOutForce control command is given, andInput from the fluid ratio setterWhen switching between reciprocating pumps with different capacities according to the required amount of fluid to be injected, when the required amount tends to increase, the pump with the smaller capacity is switched to the pump with the larger capacity. Switch operationFlow rate setting valueThan when the required volume is decreasing, the operation is switched from the larger capacity pump to the smaller capacity pump.Flow rate setting valueIs smallerThe point where the operation of the reciprocating pump should be switched is shifted so thatSince it is an operation control device of a multiple pump device having a configuration comprising a control device, hysteresis can be given to the switching point of each pump on the small capacity side and the large side, and at any fluid demand However, there is no risk of a sudden change in the rotational speed of the motor or the pump stroke of each pump, so that the influence of disturbance can be kept small, and the multiple pumps obtained by combining the capacity ranges of each pump In any part of the wide rangeability of the apparatus, accurate fluid ejection can be performed to satisfy the fluid requirement.
(2) Using the pump motor of the existing equipment, a small pump is added to the motor to form a multi-pump device, and the multi-pump device of the present invention is used in the multi-pump device. ofoperationSystemDressBy applying the device, it is possible to obtain a pump that satisfies a wide range ability without adding electric equipment or piping.
(3) By using a general-purpose programmable controller as a control device, it becomes possible to individually set performance curves unique to each pump, and proper operation can be maintained.
(4) Also, the discharge side of the multiple pump systemA pressure gauge that detects the discharge side pressure of the multiple pump device is installed in the fluid supply pipe connected to the pipe, and the detected value of the pressure gauge is input.Pressure correction command to control deviceWith a pressure controller that emits,By adopting a configuration in which pressure correction is performed on the required amount of fluid to be injected in consideration of the change in capacity of the positive displacement pump due to the change in the discharge side pressure of the multiple pump device, the positive displacement pump The capacity control of each pump can be accurately performed, and the influence of fluctuations in the discharge side pressure of the multiple pump device can be reduced.
(5) In addition, multiple pump deviceofvomitThe fluid supply pipe connected to the side is injected from the multiple pump device through the fluid supply pipeFlow meter for measuring fluid flow rateInstall the flow meterDepending on the detected valueInput from the fluid ratio setter to the controllerA flow control mechanism to correct the required amount of fluid, Provided between the fluid ratio setting device and the control deviceWith this configuration, the fluid discharge amount from the multiple pump device is fed back to correct the required fluid amount, so that feedback flow rate control can be performed and the fluid supply amount can be reduced. It becomes possible to control with higher accuracy.
[Brief description of the drawings]
FIG. 1 shows the operation control of the multiple pump device of the present invention.DressIt is a schematic diagram showing one embodiment of a device.
2 shows details of a control device used in the device of FIG. 1, (A) is a detailed diagram of a control circuit, (B) is a diagram showing a stroke set value of a small capacity pump, (C) Is a diagram showing the stroke set value of the large capacity pump, (D) is a diagram showing the output set value of the inverter.
FIG. 3 shows the operating state of each pump of the multiple pump controlled by the control device shown in FIG. 2. (A) is a diagram showing a case where the required amount of odorant tends to increase. ) Is a diagram showing a case where the required amount of odorant tends to decrease.
FIG. 4 is a schematic diagram showing still another embodiment of the present invention.
5 shows the stroke setting values of the three pumps used in the embodiment of FIG. 4 corresponding to FIGS. 2 (a) and 2 (b), where (a) is the stroke setting value of the small capacity pump. , (B) shows the stroke setting value of the medium capacity pump, and (c) shows the stroke setting value of the large capacity pump.
6 shows the operation state of each pump of the multiple pump controlled by the control device of FIG. 4, wherein (a) shows a case where the required amount of odorant tends to increase, (b) These are figures which show the case where the amount of required odorants tends to decrease.
FIG. 7 is a schematic diagram showing an example of a conventionally proposed multiple pump device.
[Explanation of symbols]
  1,1a Multiple pump system
  2 Large capacity pump (reciprocating pump)
  2a Medium capacity pump (reciprocating pump)
  3,3a Small capacity pump (reciprocating pump)
  4 Stroke adjustment mechanism
  5 Stroke adjustment mechanism
  6 Electric motor
  7 Inverter (rotational speed control mechanism)
  8 Odorant (fluid)
  11  Fluid supply pipe
  13  Odor ratio setting device (fluid ratio setting device)
  14, 14a Control device
  57  Pressure gauge
  58  Pressure controller
  60 Flow meter
  61 Calculator (flow rate control mechanism)
  64 Large capacity pump (reciprocating pump)
  65 Stroke adjustment mechanism
  F₀  Required amount of odorant (required amount)
  F₁  Detected value
  C_S1  Stroke control command
  C_S2  Stroke control command
  C_P  Output control command
  Cr pressure correction command
  P Pressure detection value

Claims (3)

Different reciprocating pump capacity equipped with a stroke adjustment mechanism separately, the required amount of fluid to be injected by multiple-pump device that is to be driven by a single motor provided with a speed control mechanism A fluid ratio setting device for determining is provided, the required amount of fluid determined by the fluid ratio setting device is input, and each reciprocating type in the multiple pump device according to the input required amount of fluid together so as to provide a stroke adjusting mechanism Niso respectively stroke control command of the pump, so as to provide the output control command to the speed control mechanism of the electric motor, further, be injected is input from the fluid ratio setter When switching the operation of the reciprocating pumps having different capacities according to the required amount of fluid to be changed, when the required amount tends to increase, the pump with the larger capacity is switched from the pump with the smaller capacity. Than the flow rate setting value for switching operation to the flop, demand is rather more smaller towards the flow rate set value for switching the operation from the pump capacity is larger side to the smaller capacity side of the pump when a downward trend An operation control apparatus for a multiple pump apparatus, characterized by comprising a control apparatus that shifts the point at which the operation of the reciprocating pump should be switched . A pressure gauge for detecting the discharge side pressure of the multiple pump apparatus is installed in the fluid supply pipe connected to the discharge side of the multiple pump apparatus, and the control value is input by inputting the detected value of the pressure gauge. Is provided with a pressure controller for issuing a pressure correction command, and pressure correction is performed on the required amount of fluid to be injected in consideration of the change in the capacity of the positive displacement pump accompanying the fluctuation of the discharge side pressure of the multiple pump device. The operation control apparatus for a multiple pump apparatus according to claim 1. A flow meter for measuring the flow rate of the fluid injected from the multiple pump device through the fluid supply tube is installed in the fluid supply tube connected to the discharge side of the multiple pump device , and the detected value of the flow meter multiple-of the flow rate control mechanism for applying a correction to the required amount of fluid that is input from the fluid ratio setter to the control device, according to claim 1 or 2, wherein provided between the fluid ratio setter and the control device by Operation control device for a pump-type pump device.

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