JP5291502B2 - Flow control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flow control device securing a flow rate discharged by an electromagnetic driving part as per a target flow rate. <P>SOLUTION: A control part 14 calculates a temperature change of a process pump 8 based on the temperature of liquid fuel sucked by the process pump 8 measured by a thermometer 9 and the ambient temperature of the process pump 8 measured by a thermometer 10, and based on the temperature change, corrects the discharge flow rate of the process pump 8 so that the flow rate of the liquid fuel in a liquid fuel supply line L2 becomes the actual target flow rate. Further, the control part 14 calculates a temperature change of a burner pump 11 based on the temperature of liquid fuel sucked by the burner pump 11 measured by a thermometer 12 and the ambient temperature of the burner pump 11 measured by a thermometer 13, and based on the temperature change, corrects the discharge flow rate of the burner pump 11 so that the flow rate of the liquid fuel in a burner fuel supply line L3 becomes the actual target flow rate. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a flow control device.

  2. Description of the Related Art A flow control device configured to send a fluid to a flow path by an electromagnetic driving unit having a coil that generates a magnetic force when energized is known (for example, see Patent Document 1). In the flow control device described in Patent Document 1, an electromagnetic pump including an electromagnetic drive unit is used, and the discharge flow rate of the electromagnetic pump is corrected based on the output from the temperature measuring means provided in the middle of the fluid flow path. doing.

Japanese Patent Application Laid-Open No. 07-083426

  By the way, when the environmental temperature of the electromagnetic drive unit (for example, the ambient temperature of the electromagnetic drive unit or the temperature of the fluid) changes, the temperature of the electromagnetic drive unit changes. And with the temperature change of an electromagnetic drive part, the resistance value of the coil of an electromagnetic drive part will change, and the electric current which flows into a coil will also change. For this reason, the driving force of an electromagnetic drive part changes and it becomes difficult to ensure the flow volume discharged by an electromagnetic drive part according to a target flow rate. Generally, when the temperature of the electromagnetic drive unit rises, the flow rate discharged by the electromagnetic drive unit decreases from the target flow rate, and when the temperature of the electromagnetic drive unit decreases, the flow rate discharged by the electromagnetic drive unit increases from the target flow rate.

  An object of this invention is to provide the flow control apparatus which can ensure the flow volume discharged by an electromagnetic drive part according to target flow volume.

  A flow control device according to the present invention is a flow control device configured to send a fluid to a flow path by an electromagnetic drive unit having a coil that generates a magnetic force when energized, and the flow rate in the flow path becomes a target flow rate. Control means for controlling the flow rate discharged by the electromagnetic drive section, and temperature detection means for detecting the temperature of the electromagnetic drive section, and the control means is based on the temperature detected by the temperature detection means. The flow rate discharged by the electromagnetic drive unit is corrected and controlled so that the flow rate in the road becomes an actual target flow rate.

  In the flow control device according to the present invention, the control means for controlling the flow rate discharged by the electromagnetic drive unit so that the flow rate in the flow path becomes the target flow rate is detected by the temperature detection means for detecting the temperature of the electromagnetic drive unit. Based on the temperature, the flow rate discharged from the electromagnetic drive unit is corrected and controlled so that the flow rate in the flow path becomes the actual target flow rate. Thereby, the discharge flow rate of an electromagnetic drive part is securable according to a target flow rate.

  Preferably, the temperature detection means includes a thermal element provided in the electromagnetic drive unit, and detects the temperature of the electromagnetic drive unit based on the output of the thermal element. In this case, the temperature of the electromagnetic drive unit can be detected easily and appropriately.

  Preferably, the temperature detection means includes an ambient temperature measurement means for measuring the ambient temperature of the electromagnetic drive section, and a fluid temperature measurement means for measuring the temperature of the fluid, and the temperature of the electromagnetic drive section measured by the ambient temperature measurement means. The temperature of the electromagnetic drive unit is detected based on the ambient temperature and the temperature of the fluid measured by the fluid temperature measuring means. In this case, the temperature of the electromagnetic drive unit can be detected without measuring the temperature of the electromagnetic drive unit itself.

  Preferably, the temperature of the electromagnetic drive unit is the temperature of the coil. In this case, it is possible to effectively correct the discharge flow rate of the electromagnetic drive unit.

  Preferably, the fluid is kerosene, water, or gas.

  ADVANTAGE OF THE INVENTION According to this invention, the flow control apparatus which can ensure the flow volume discharged by an electromagnetic drive part according to target flow volume can be provided.

It is a block diagram which shows the hydrogen production apparatus which concerns on this embodiment. It is a flowchart which shows the control action of a process pump and a burner pump. It is a block diagram which shows the modification of the hydrogen production apparatus which concerns on this embodiment. It is a block diagram which shows the modification of the hydrogen production apparatus which concerns on this embodiment.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description, the same reference numerals are used for the same elements or elements having the same function, and redundant description is omitted.

  FIG. 1 is a configuration diagram illustrating a hydrogen production apparatus according to the present embodiment. In this embodiment, the example which applied this invention to the hydrogen production apparatus used for a fuel cell system, for example is shown. As shown in FIG. 1, a hydrogen production apparatus 1 includes a reformer 2 that generates a reformed gas containing hydrogen, and a desulfurizer 3 that removes sulfur from liquid fuel to be supplied to the reformer 2. And. In the hydrogen production apparatus 1, hydrocarbon fuel is used as the liquid fuel from the viewpoint that it can be easily obtained and can be stored independently.

An example of the hydrocarbon fuel is kerosene. The hydrocarbon fuel targeted in this embodiment has, for example, a carbon content of liquid feed of 80 to 90% by mass, a density at 15 ° C. of 0.7 to 0.9 g / cm ³ , and 30 The kinematic viscosity at ° C. is 1.0 to 5.0 mm ² / s, and has a sulfur compound of 10 mass ppm or less based on the total sulfur compound of the liquid feeding.

  The reformer 2 includes a reformer 2a for steam reforming a liquid fuel to generate a reformed gas, a burner 2b for heating a reforming catalyst accommodated in the reformer 2a, and carbon monoxide by an aqueous shift reaction. And a selective oxidation reaction part (not shown) for further reducing carbon monoxide by a selective oxidation reaction. Although not shown, the desulfurization device 3 has a desulfurizer that accommodates a desulfurization catalyst that removes sulfur from the liquid fuel supplied to the reformer 2.

  A liquid fuel supply line L <b> 1 for supplying liquid fuel stored in the fuel tank 5 is connected to the desulfurization device 3. The liquid fuel supply line L1 is provided with a tank feed pump 6 and a desulfurization pump 7 from the fuel tank 5 side. Therefore, the kerosene stored in the fuel tank 5 is pumped to the tank feed pump 6 and the desulfurization pump 7 and sent to the desulfurization device 3.

  The liquid fuel from which the sulfur content has been removed by the desulfurization device 3 is sent to the reforming device 2 (reformer 2a) via the liquid fuel supply line L2. A process pump 8 is provided in the liquid fuel supply line L2. A liquid fuel supply line L2 between the desulfurization apparatus 3 and the process pump 8, that is, a preceding stage of the process pump 8 in the liquid fuel supply line L2, is a thermometer (fluid) that measures the temperature of the liquid fuel sucked into the process pump 8. Temperature measuring means) 9 is provided. The process pump 8 is provided with a thermometer (ambient temperature measuring means) 10 for measuring the ambient temperature of the process pump 8.

  A burner fuel supply line L3 for branching from the liquid fuel supply line L1 between the tank feed pump 6 and the desulfurization pump 7 and supplying a part of the liquid fuel to the burner 2b of the reformer 2 is provided. Yes. A burner pump 11 is provided in the burner fuel supply line L3. A thermometer (temperature measuring means) 12 for measuring the temperature of the liquid fuel sucked into the burner pump 11 is provided in the preceding stage of the burner pump 11 in the burner fuel supply line L3. The burner pump 11 is provided with a thermometer (ambient temperature measuring means) 13 for measuring the ambient temperature of the burner pump 11.

  The process pump 8 and the burner pump 11 are known constant flow type electromagnetic pumps, and include, as an electromagnetic drive unit, a coil unit that generates a magnetic force by energization, a plunger unit that operates by the magnetic force generated in the coil unit, and the like. It is out. The electromagnetic pump used for the process pump 8 and the burner pump 11 includes a flow rate of 1 g / min in the working flow rate range, and has a flow rate accuracy within ± 5% based on the flow rate value in the flow rate range of 0.3 to 5 g / min. doing. A constant flow type electromagnetic pump can also be used for the tank feed pump 6 and the desulfurization pump 7.

  The operations of the process pump 8 and the burner pump 11 are controlled by a control unit (control means) 14. That is, the control unit 14 controls the discharge flow rate of the process pump 8 so that the flow rate in the liquid fuel supply line L2 becomes the target flow rate, and the burner pump 11 so that the flow rate in the burner fuel supply line L3 becomes the target flow rate. The discharge flow rate is controlled. Although not described, the control unit 14 also controls the tank feed pump 6 and the desulfurization pump 7.

  Outputs from the thermometers 9, 10, 12, and 13 are connected to the control unit 14, respectively, and the temperature of the liquid fuel sucked into the process pump 8, the ambient temperature of the process pump 8, and the burner pump 11 are sucked into the controller 14. Each information relating to the temperature of the liquid fuel and the ambient temperature of the burner pump 11 is input. The control unit 14 calculates the temperature of the process pump 8 based on the temperature of the liquid fuel sucked into the process pump 8 measured by the thermometers 9 and 10 and the ambient temperature of the process pump 8. It also has the function of detecting the temperature of The control unit 14 calculates the temperature of the burner pump 11 based on the temperature of the liquid fuel sucked into the burner pump 11 measured by the thermometers 12 and 13 and the ambient temperature of the process pump 8. It also has a function of detecting the temperature of the pump 11.

  Here, control of the process pump 8 and the burner pump 11 by the control unit 14 will be described. FIG. 2 is a flowchart showing control operations of the process pump and the burner pump.

  As shown in FIG. 2, when the control of the process pump 8 and the burner pump 11 is started, the control unit 14 determines each target flow rate of the process pump 8 and the burner pump 11 based on the operation state of the hydrogen production apparatus 1. Is determined (S101). The target flow rate is such that the temperature of the liquid fuel is the predetermined temperature when the hydrogen production apparatus 1 (fuel cell system) is operated at a predetermined outside temperature, and the ambient temperatures of the process pump 8 and the burner pump 11 are the predetermined temperatures. Is set under certain conditions. For example, the outside air temperature is 25 ° C., and the temperature of the liquid fuel and the ambient temperatures of the process pump 8 and the burner pump 11 are 47 ° C.

  The control unit 14 determines a density correction coefficient based on the temperature of the liquid fuel sucked into the process pump 8 measured by the thermometer 9, and the liquid sucked into the burner pump 11 measured by the thermometer 12. A density correction coefficient is determined based on the temperature of the fuel (S103). The density correction coefficient is a coefficient for correcting a change in the discharge flow rate due to the change in the density of the liquid fuel in accordance with the temperature of the liquid fuel, and when the temperature of the liquid fuel is higher than the temperature at which the target flow rate is set. Is set to increase the discharge flow rate, and to decrease the discharge flow rate when the temperature of the liquid fuel is lower than the temperature at which the target flow rate is set.

  Further, the control unit 14 calculates the temperature of the process pump 8 based on the temperature of the liquid fuel sucked into the process pump 8 measured by the thermometer 9 and the ambient temperature of the process pump 8 measured by the thermometer 10. The temperature of the burner pump 11 is calculated based on the temperature of the liquid fuel sucked into the burner pump 11 measured by the thermometer 12 and the ambient temperature of the burner pump 11 measured by the thermometer 13 (S105). Here, each temperature change of the coil of the process pump 8 and the burner pump 11 is calculated.

Each temperature change ΔTcoil of the coils of the process pump 8 and the burner pump 11 can be calculated as follows, for example. The heat balance in the coil of the pump is
Q + a * (Toil-Tcoil) + b * (Tenv-Tcoil) = 0
It is represented by here,
Q: Coil heat generated by operation (W)
Toil: Liquid fuel temperature (℃)
Tcoil: Coil temperature (℃)
Tenv: Ambient temperature of pump (℃)
It is.

When the target flow rate is set such that the temperature of the liquid fuel and the ambient temperature of the pump are 47 ° C., the coil temperature Tcoil before the temperature change and the coil temperature Tcoil after the temperature change are:
Tcoil (before temperature change) = Q / (a + b) + a / (a + b) * 47 + b / (a + b) * 47
Tcoil (before temperature change) = Q ′ / (a + b) + a / (a + b) * Toil + b / (a + b) * Tenv
It is represented by here,
Q ≒ Q '
Then, the temperature change ΔTcoil of the coil is
ΔTcoil = a / (a + b) * (Toil−47) + b / (a + b) * (Tenv−47)
It is represented by Then, when the coefficients a and b are appropriately set from the experiment, the temperature change ΔTcoil of the coil is
ΔTcoil = 0.509 * (Toil-47) + 0.491 * (Tenv-47)
Can be calculated.

  Then, the control unit 14 determines a correction coefficient due to the temperature change of the process pump 8 based on the calculated temperature change of the process pump 8, and the correction coefficient due to the temperature change of the burner pump 11 based on the calculated temperature of the burner pump 11. Is determined (S107). The correction coefficient due to the temperature change is a coefficient for correcting the change in the discharge flow rate due to the change in the resistance value of the coils of the pumps 8 and 11 according to the temperature of the pumps 8 and 11 (coils). When the ambient temperature of the pumps 8 and 11 is higher than the temperature at which the target flow rate is set, the discharge flow rate is increased, and when the temperature of the liquid fuel and the ambient temperature of the pump are lower than the temperature at which the target flow rate is set Is set to reduce the discharge flow rate.

  Then, the control unit 14 corrects the target flow rate with the determined density correction coefficient and the correction coefficient due to temperature change, and determines the final target flow rates of the process pump 8 and the burner pump 11 (S109). Furthermore, the control unit 14 determines the drive frequency (Hz) and the drive pulse width (msec) of the process pump 8 and the burner pump 11 from the control map or the like based on the final target flow rates of the process pump 8 and the burner pump 11. The drive signal is output to the process pump 8 and the burner pump 11 (S111). As a result, the discharge flow rate of the process pump 8 is corrected so that the liquid fuel flow rate in the liquid fuel supply line L2 becomes the actual target flow rate, and the liquid fuel flow rate in the burner fuel supply line L3 becomes the actual target flow rate. Thus, the discharge flow rate of the burner pump 11 is corrected.

  As described above, in the present embodiment, the control unit 14 is based on the temperature of the liquid fuel sucked into the process pump 8 measured by the thermometer 9 and the ambient temperature of the process pump 8 measured by the thermometer 10. The temperature change of the process pump 8 is calculated, and based on the calculated temperature change, the discharge flow rate of the process pump 8 is corrected and controlled so that the flow rate of the liquid fuel in the liquid fuel supply line L2 becomes the actual target flow rate. Yes. Further, the control unit 14 calculates the temperature change of the burner pump 11 based on the temperature of the liquid fuel sucked into the burner pump 11 measured by the thermometer 12 and the ambient temperature of the burner pump 11 measured by the thermometer 13. Based on the calculated temperature change, the discharge flow rate of the burner pump 11 is corrected and controlled so that the flow rate of the liquid fuel in the burner fuel supply line L3 becomes the actual target flow rate. Thereby, the discharge flow rate of the process pump 8 and the burner pump 11 can be ensured according to the target flow rate.

  In particular, the electromagnetic pump used for the process pump 8 and the burner pump 11 in the hydrogen production apparatus 1 of the fuel cell system is small in size, has a low discharge flow rate, and is susceptible to external factors. Therefore, the target flow rate correction control based on the temperature change of the electromagnetic pump (coil) in this embodiment is extremely useful for a small-sized electromagnetic pump with a low discharge flow rate.

  In the present embodiment, the temperature change of the process pump 8 is calculated based on the temperature of the liquid fuel sucked into the process pump 8 measured by the thermometer 9 and the ambient temperature of the process pump 8 measured by the thermometer 10. The temperature change of the burner pump 11 is calculated based on the temperature of the liquid fuel sucked into the burner pump 11 measured by the thermometer 12 and the ambient temperature of the burner pump 11 measured by the thermometer 13. Thereby, the temperature change of each pump 8 and 11 is detectable, without measuring the temperature of each pump 8 and 11 itself.

  In this embodiment, the coil temperature of each pump 8 and 11 is used as the temperature of each pump 8 and 11. Thereby, the correction | amendment of the discharge flow rate of each pump 8 and 11 can be performed effectively.

  The preferred embodiments of the present invention have been described above. However, the present invention is not necessarily limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

  In the present embodiment, the temperature change of the process pump 8 is calculated based on the temperature of the liquid fuel sucked into the process pump 8 measured by the thermometer 9 and the ambient temperature of the process pump 8 measured by the thermometer 10, The temperature change of the burner pump 11 is calculated based on the temperature of the liquid fuel sucked into the burner pump 11 measured by the thermometer 12 and the ambient temperature of the burner pump 11 measured by the thermometer 13. The calculation methods of the temperature change of 8 and 11 are not limited to these.

  For example, as shown in FIG. 3, the temperature change of the process pump 8 is calculated only based on the temperature of the liquid fuel sucked into the process pump 8 measured by the thermometer 9 without providing the thermometers 10 and 13. The temperature change of the burner pump 11 may be calculated only based on the temperature of the liquid fuel sucked into the burner pump 11 measured by the thermometer 12. The ambient temperature of each pump 8, 11 is affected by the temperature of the liquid fuel flowing through each pump 8, 11. That is, the ambient temperature of each pump 8, 11 is highly correlated with the temperature of the liquid fuel. Therefore, the temperature change of each pump 8, 11 can be calculated without using the ambient temperature of each pump 8, 11. In this case, cost reduction and system simplification can be achieved.

  Further, as shown in FIG. 4, a temperature sensing element 15 that directly measures the body temperature of the process pump 8 is provided in the process pump 8, and a temperature sensing element 16 that directly measures the body temperature of the burner pump 11 is provided in the burner pump 11. The temperature changes of the pumps 8 and 11 may be detected based on the output signals from the temperature sensitive elements 15 and 16.

  In this embodiment, although the example which applied this invention to the flow control apparatus of the electromagnetic pump (process pump 8 and burner pump 11) used for the hydrogen production apparatus 1 of a fuel cell system was shown, it is not restricted to this. The present invention can be applied as long as the fluid is sent to the flow path by the electromagnetic drive unit. For example, the flow control device of the electromagnetic pump used in the oil fan heater in which the fluid is kerosene, the fluid is water. The present invention can be applied to a flow control device for a fuel cell water pump, a diaphragm air pump for a fuel cell in which the fluid is a gas, a fan, or a flow control device for a blower.

DESCRIPTION OF SYMBOLS 1 ... Hydrogen production apparatus, 2 ... Reformer, 3 ... Desulfurization apparatus, 5 ... Fuel tank, 6 ... Tank feed pump, 7 ... Desulfurization pump, 8 ... Process pump, 9, 10, 12, 13 ... Thermometer, 11 DESCRIPTION OF SYMBOLS ... Burner pump, 14 ... Control part, 15, 16 ... Temperature sensing element, L1 ... Liquid fuel supply line, L2 ... Liquid fuel supply line, L3 ... Fuel supply line for burners.

Claims (4)

A flow rate control device configured to send a fluid to a flow path by an electromagnetic drive unit having a coil that generates a magnetic force when energized,
Control means for controlling the flow rate discharged by the electromagnetic drive unit so that the flow rate in the flow path becomes the target flow rate;
Ambient temperature measuring means for measuring ambient temperature of the electromagnetic drive unit;
Fluid temperature measuring means for measuring the temperature of the fluid ,
The control means calculates the temperature change of the coil based on the ambient temperature of the electromagnetic drive unit measured by the ambient temperature measurement unit and the temperature of the fluid measured by the fluid temperature measurement unit, Based on the temperature change of the coil, the correction coefficient due to the temperature change of the electromagnetic drive unit is determined, the target flow rate is corrected by the determined correction coefficient, and the electromagnetic drive so that the flow rate in the flow path becomes the actual target flow rate A flow rate control device for controlling a flow rate discharged by the unit. A flow control device for an electromagnetic pump having a coil that generates magnetic force when energized and used in a hydrogen production device of a fuel cell system,
Control means for controlling the flow rate discharged by the electromagnetic pump so that the flow rate in the flow path becomes the target flow rate;
Ambient temperature measuring means for measuring ambient temperature of the electromagnetic pump;
Fluid temperature measuring means for measuring the temperature of the fluid,
The control means calculates a temperature change of the coil based on the ambient temperature of the electromagnetic pump measured by the ambient temperature measurement means and the temperature of the fluid measured by the fluid temperature measurement means, and the calculated coil The correction coefficient due to the temperature change of the electromagnetic pump is determined on the basis of the temperature change of the electromagnetic pump, the target flow rate is corrected by the determined correction coefficient, and the discharge is performed by the electromagnetic pump so that the flow rate in the flow path becomes the actual target flow rate. The flow rate control apparatus characterized by controlling the flow volume made. The electromagnetic pump is provided in a liquid fuel transmission line for sending liquid fuel from which sulfur content has been removed by a desulfurization device to the reformer,
3. The flow rate control device according to claim 2 , wherein the fluid temperature measuring unit is provided in a front stage of the electromagnetic pump in the liquid fuel transmission line and measures the temperature of the liquid fuel sucked into the electromagnetic pump. . The electromagnetic pump is provided in a burner fuel supply line for supplying a part of the liquid fuel to the burner of the reformer,
3. The flow rate control according to claim 2 , wherein the fluid temperature measuring unit is provided in a stage preceding the electromagnetic pump in the burner fuel supply line, and measures the temperature of the liquid fuel sucked into the electromagnetic pump. apparatus.

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