JP6280353B2 - Liquefied fuel gas vaporizer - Google Patents

Description

  The present invention relates to a liquefied fuel gas vaporizer.

  Conventionally, a liquid phase liquefied gas fuel such as LPG (liquefied petroleum gas) is vaporized by a liquefied fuel gas vaporizer to become a fuel gas (see Patent Document 1). The liquefied fuel gas vaporizer is, for example, a method of heating and vaporizing liquid phase liquefied gas fuel with an electric heater, or heating and vaporizing liquid phase liquefied gas fuel with a heat transfer fluid heated by the combustion heat of the fuel gas. There is a method of letting you.

JP 2001-116197 A

  In such a liquefied fuel gas vaporizer, the inside of the housing is certified as a hazardous place in the main regulations and technical guidelines related to explosion-proof electrical equipment and facilities. For this reason, an explosion-proof structure must be used as a component in the housing, which has been a factor in increasing costs.

  The present invention has been made in order to solve such a conventional problem, and an object of the present invention is to vaporize a liquefied fuel gas capable of adopting a structural component other than an explosion-proof structure for a structural component in a housing. To provide an apparatus.

The liquefied fuel gas vaporizer according to the present invention includes an introduction channel for introducing a liquid gas fuel, an evaporator for vaporizing the liquid gas fuel introduced through the introduction channel by heating with a heating source, and the evaporation A liquefied fuel gas vaporizer comprising: a discharge passage for discharging fuel gas vaporized by a vaporizer; and a control panel for controlling the heating source, wherein the introduction passage, the evaporator, and the discharge passage And a housing that houses the control panel, and an inside air exhaust fan that is provided in the housing and exhausts the gas inside the housing to the outside of the housing , and allows the gas outside the housing to flow inside the housing An outside air introduction fan for increasing the internal pressure of the housing by being introduced into the housing is not provided, and a predetermined amount of gas inside the housing is discharged outside the housing by the inside air discharge fan .

According to the liquefied fuel gas vaporizer of the present invention, since the inside air exhaust fan that exhausts the gas inside the housing to the outside of the housing is provided in the housing, it is assumed that fuel gas or the like leaks from the structural components inside the housing. However, this can be discharged to the outside by the inside air discharge fan. As a result, the inside of the housing can be kept below the lower limit of fuel gas explosion. Accordingly, it is possible to adopt a structure component other than the explosion-proof structure for the structural component in the housing.

Moreover, in the liquefied fuel gas vaporizer, it is preferable that the inside air discharge fan discharges gas of 5 times or more of the inside volume of the housing to the outside of the housing per hour.

According to this liquefied fuel gas vaporizer, the inside air discharge fan discharges gas more than 5 times the inside volume of the housing per hour, so the inside of the housing is recognized as a so-called non-hazardous area, and the structure inside the housing There is no need to use any explosion-proof parts for the parts, which can eliminate the cost increase factor.

In the liquefied fuel gas vaporizer, it is preferable that the control panel detects an abnormality of the inside air discharge fan when an output pulse width of the fan motor during the inside air discharge fan operation is a predetermined width or more.

According to the liquefied fuel gas vaporizer, since the output pulse width of the fan motor at the time of the inside air discharge fan operation to detect an abnormality of the internal air exhaust fan in the case where more than a predetermined width, the rotational speed of the internal air exhaust fan is reduced An abnormality can be detected when the amount of gas discharged out of the housing decreases.

  ADVANTAGE OF THE INVENTION According to this invention, the liquefied fuel gas vaporization apparatus which can employ | adopt things other than explosion-proof structure about the structural components in a housing | casing can be provided.

It is a block diagram which shows the liquefied fuel gas vaporization apparatus which concerns on embodiment of this invention. It is a circuit diagram which detects the drive state of the fan of the liquefied fuel gas vaporization apparatus which concerns on this embodiment. It is a figure which shows the pulse at the time of the rotational drive of a fan. It is a flowchart which shows the processing operation of the liquefied fuel gas vaporization apparatus which concerns on this embodiment, and has shown the processing operation regarding a drive of a fan and abnormality detection.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings. The present invention is not limited to the embodiments shown below.

  FIG. 1 is a configuration diagram showing a liquefied fuel gas vaporizer 100 according to an embodiment of the present invention. As shown in FIG. 1, a liquefied fuel gas vaporizer 100 includes a water tank 1, a heat transfer pipe (evaporator) 2, a regulating valve 3, an inflow pipe (introduction flow path) 4, and an outflow pipe (discharge flow path). 5, a thermo valve 6, and a temperature sensing unit 7.

  The water tank 1 stores water that is a heat medium liquid (heating source). The heat transfer pipe 2 is a pipe formed in a coil shape, and is connected to an inflow pipe 4 for introducing liquid-phase liquefied gas fuel (hereinafter referred to as liquid-phase gas fuel) via a regulating valve 3 at one end. An outflow pipe 5 for discharging the vaporized liquefied fuel gas (hereinafter referred to as fuel gas) is connected to the end. The heat transfer tube 2 heats and vaporizes the liquid-phase gas fuel by exchanging heat between the liquid-phase gas fuel introduced through the inflow tube 4 and the heat transfer fluid.

  The liquid gas fuel inflow pipe 4 is connected to a liquefied fuel gas storage tank (which stores liquid fuel) (not shown). The fuel gas outflow pipe 5 is connected to a fuel gas use device (not shown).

  The thermo valve 6 is provided on the upstream side of the regulating valve of the inflow pipe 4, and opens when the detected water temperature by the temperature sensing unit 7 inserted into the stored water in the water tank 1 becomes equal to or higher than the set temperature. That is, the thermo valve 6 has a structure that prevents the liquid gas fuel from reaching the outflow pipe 5 when the stored water in the water tank 1 is low temperature and the liquid gas fuel cannot be vaporized. It has become.

  The liquefied fuel gas vaporizer 100 includes a combustion chamber 8, a burner (heating source) 9, a blower 10, a fuel gas supply pipe 11, and a control valve 12.

  The combustion chamber 8 is provided in the bottom part in the water tank 1, and functions as a space part which burns fuel gas. A burner 9 is connected to the combustion chamber 8, and a blower 10 and a fuel gas supply pipe 11 are connected to the combustion chamber 8. The blower 10 is a device that sends air into the combustion chamber 8. The fuel gas supply pipe 11 is a pipe for sending fuel gas into the combustion chamber 8. The fuel gas supply pipe 11 is provided with a control valve 12 that adjusts the supply and non-supply of the fuel gas and the flow rate. Further, the fuel gas supply pipe 11 is connected to the outflow pipe 5 and is configured to introduce the fuel gas vaporized by the apparatus 100. The fuel gas supply pipe 11 is not limited to being connected to the outflow pipe 5 but may be connected to another gas supply device or the like.

  The burner 9 burns the fuel gas sent through the fuel gas supply pipe 11. In the present embodiment, the combustion chamber 8 has a length that is about half the lateral distance of the water tank 1 as shown in FIG. For this reason, in this embodiment, the burner 9 does not need to use a ceramic burner with a short flame length, and is constituted by a blast burner.

  Furthermore, the liquefied fuel gas vaporizer 100 includes a heat exchange unit 13, an exhaust pipe 14, a temperature switch 15, a water level switch 16, a control panel 17, and a power supply panel 18.

  The heat exchanging portion 13 is composed of a pipe extending upward from the combustion chamber 8 and a heater pipe composed of a plurality of fins provided on the inner peripheral surface thereof. As shown in FIG. It passes near the coil axis of 2. In this heat exchanging portion 13, heat exchange between the stored water in the water tank 1 and the combustion exhaust gas is promoted by a plurality of fins. The exhaust tube 14 is a pipe provided on the upper side of the water tank 1 continuously to the heat exchange unit 13. The combustion exhaust gas is discharged from the exhaust cylinder 14 to the outside. In addition, an umbrella 14 a is provided at the tip of the exhaust tube 14, so that rainwater or the like does not easily enter the exhaust tube 14.

  The temperature switch 15 is provided on the side surface of the water tank 1 and detects the water temperature in the water tank 1. The water level switch 16 is provided on the upper surface of the water tank 1 and detects the water level in the water tank 1. The control panel 17 controls the entire apparatus 100. For example, according to a signal from the temperature switch 15, the burner 9 and the blower are used to keep the water temperature in the water tank 1 at a predetermined temperature (for example, 70 ° C.). 10 and the control valve 12 are controlled. Further, the control panel 17 outputs an alarm at the first stage where the water level is slightly reduced in response to a signal from the water level switch 16, and stops combustion by the burner 9 at the second stage where the water level is greatly reduced. The power supply panel 18 supplies control power to the control panel 17 and is installed in a non-hazardous area where no flammable gas exists.

  The liquefied fuel gas vaporizer 100 includes an overheat prevention switch 19, a thermometer 20, a water level gauge 25, a wind pressure switch 21, and an exhaust gas temperature switch 22.

  The overheat prevention switch 19 detects the water temperature in the water tank 1 like the temperature switch 15, and the on / off temperature of the switch is different from that of the temperature switch 15. That is, the detected temperature of the overheat prevention switch 19 is set to an abnormal overheat temperature (for example, 85 ° C.), and the control panel 17 performs combustion by the burner 9 when the overheat prevention switch 19 detects the abnormal overheat temperature. Stop.

  The thermometer 20 and the water level meter 25 are displayed so that an operator or the like can visually recognize the water temperature and the water level. The wind pressure switch 21 detects the blowing pressure of the blower 10. The control panel 17 stops the combustion by the burner 9 when it can be determined from the signal from the wind pressure switch 21 that the blowing pressure has decreased extremely.

  The exhaust gas temperature switch 22 is provided on the side surface of the exhaust cylinder 14 and detects the temperature of the combustion exhaust gas. When the exhaust gas temperature switch 22 detects an abnormal overheating temperature (for example, 200 ° C.) of the combustion exhaust gas, the control panel 17 stops the combustion by the burner 9.

  Furthermore, the liquefied fuel gas vaporizer 100 includes a housing 23 that houses the above-described parts 1 to 17, 19 to 22 and 25 (excluding the umbrella 14a and the power panel 18). In addition, the liquefied fuel gas vaporizer 100 includes a fan 24 in the housing 23. The fan 24 is installed, for example, on the inner side wall of the casing 23 and discharges gas inside the casing out of the casing through an opening provided in the casing wall.

  Such a fan 24 has, for example, a DC brushless motor (fan motor), starts driving when the power of the liquefied fuel gas vaporizer 100 is turned on, and stops driving when the power of the liquefied fuel gas vaporizer 100 is turned off. . That is, the fan 24 is always driven when the liquefied fuel gas vaporizer 100 is on. In addition, the fan 24 has a capacity for discharging gas that is 5 times or more the internal volume of the housing 23 per hour by driving at all times.

  FIG. 2 is a circuit diagram for detecting the driving state of the fan 24 of the liquefied fuel gas vaporizer 100 according to the present embodiment. As shown in FIG. 2, in the fan 24, a fan driving power source (not shown) is connected to the first terminal 24a, and the second terminal 24b is grounded. Moreover, the detection circuit 25 which detects the drive state of the liquefied fuel gas vaporization apparatus 100 is provided.

  The detection circuit 25 is a so-called open collector type detection circuit, and includes an NPN transistor Tr provided in the fan 24 and a pull-up resistor R. One end of the pull-up resistor R is connected to the pull-up power supply, and the other end is connected to the collector C of the NPN transistor Tr. The emitter E of the NPN transistor Tr is grounded. The base B of the NPN transistor Tr receives a rotation signal when the motor of the fan 24 rotates.

  In such a detection circuit 25, when a high level voltage is applied to the base B of the NPN transistor Tr, the NPN transistor Tr is turned on and a current Ic flows between the collector and the emitter. That is, the connection point A between the pull-up resistor R and the collector C of the NPN transistor Tr is grounded and becomes low level. On the other hand, when a low level voltage is applied to the base B of the NPN transistor Tr, the NPN transistor Tr is turned off, and the connection point A becomes a high level. The control panel 17 monitors the operating state of the fan 24 by monitoring the voltage at the connection point A.

  FIG. 3 is a diagram illustrating pulses when the fan 24 is rotationally driven. As shown in FIG. 3, the fan 24 used in this embodiment rotates once by a pulse of two cycles. For this reason, the control panel 17 rises at time t1, falls at time t2, rises at time t3, falls at time t4, and rises at time t5. Can be detected.

  Here, the time from time t1 to time t2 is T1, the time from time t2 to time t3 is T2, the time from time t3 to time t4 is T3, and the time from time t4 to time t5 is T4. When the time from time t1 to time t5 is T0, the output pulse widths T1 to T4 of the DC brushless motor during rated operation can be expressed as T1 to T4 = T0 / 4 = 60 / 4N.

When N is the rotational speed and the value is 6500 (min ⁻¹ ), the pulse widths T1 to T4 are T1 to T4≈2.3 ms.

The control panel 17 detects an abnormality of the fan 24 when the pulse widths T1 to T4 as described above are equal to or larger than a predetermined width. More specifically, the maximum air volume of the fan 24 in the present embodiment is 0.15 m ³ / min, when the operation air volume has to be 0.075 m ³ / min, fell to the air volume 0.013 m ³ / min Sometimes it is determined to be abnormal. That is, the predetermined width = 2.3 ms × (0.075 / 0.013) ≈13 ms, and the control panel 17 detects the abnormality of the fan 24 when the pulse widths T1 to T4 are 13 ms or more.

  Further, when detecting an abnormality of the fan 24, the control panel 17 turns on a fan abnormality lamp provided on the surface of the control panel 17 and outputs an alarm.

  FIG. 4 is a flowchart showing the processing operation of the liquefied fuel gas vaporizer 100 according to the present embodiment, and shows the processing operation related to driving of the fan 24 and abnormality detection. First, as shown in FIG. 4, when the power of the liquefied fuel gas vaporizer 100 is turned on, the fan 24 starts operation (S1).

  Thereafter, the determination circuit of the control panel 17 determines whether the pulse widths T1 to T4 are equal to or larger than a predetermined width (S2). When it is determined that the pulse widths T1 to T4 are not greater than or equal to the predetermined width (S2: NO), the process proceeds to step S6.

  When it is determined that the pulse widths T1 to T4 are greater than or equal to the predetermined width (S2: YES), the determination circuit of the control panel 17 determines whether or not the state continues for a predetermined time (for example, 1 hour) (S3). . If it is determined that it has not continued for a predetermined time (S3: NO), the process proceeds to step S6. In this way, by determining the continuation for a predetermined time or longer, the fan 24 is not determined to be abnormal due to a temporary decrease in the amount of airflow such as a reverse wind.

  When it is determined that the operation has continued for a predetermined time (S3: YES), the determination circuit of the control panel 17 detects an abnormality of the fan 24 (S4), turns on the fan abnormality lamp, and outputs an alarm (S5).

  Thereafter, if the power is not turned off (S6: NO), the process proceeds to step S2. When the power is turned off (S6: YES), the fan 24 is stopped (S7), and the processing operation shown in FIG. Ends.

  Thus, according to the liquefied fuel gas vaporizer 100 according to the present embodiment, the fan 24 that discharges the gas inside the casing to the outside of the casing is provided in the casing. Even if gas or the like leaks, it can be discharged to the outside by the fan 24. As a result, the inside of the housing can be kept below the lower limit of fuel gas explosion. Accordingly, it is possible to adopt a structure component other than the explosion-proof structure for the structural component in the housing.

  Further, since the fan 24 discharges more than five times the internal volume of the housing 23 per hour to the outside of the housing, the inside of the housing is recognized as a so-called non-hazardous area, and the structural parts in the housing are of an explosion-proof structure. There is no need to use anything, and the cost increase factor can be eliminated.

  Further, when the fan motor output pulse width during the fan operation is greater than or equal to a predetermined width, an abnormality of the fan 24 is detected, so that the rotational speed of the fan 24 decreases and the amount of gas discharged outside the housing decreases. An abnormality can be detected.

  As described above, the present invention has been described based on the embodiment, but the present invention is not limited to the above embodiment, and may be modified without departing from the gist of the present invention.

  For example, in the said embodiment, although the heat exchange part 13 becomes a structure which passes the coil axis | shaft of the coil-shaped heat exchanger tube 2, it is not restricted to this. For example, the heat exchange unit 13 may be formed to extend from the combustion chamber 8 to the side, and the exhaust pipe 14 may be installed on the side of the water tank 1.

  Furthermore, the liquefied fuel gas vaporizer according to the present embodiment is of a type that heats and vaporizes liquid-phase gas fuel with a heat medium liquid, but is not limited thereto, and liquid-phase gas fuel is generated by an electric heater. A method of heating and vaporizing may be used.

1 ... Water tank 2 ... Heat transfer tube (evaporator)
3 ... Regulating valve 4 ... Inflow pipe (introduction flow path)
5 ... Outflow pipe (discharge channel)
6 ... Thermo valve 7 ... Temperature sensing part 8 ... Combustion chamber 9 ... Burner 10 ... Blower 11 ... Fuel gas supply pipe 12 ... Control valve 13 ... Heat exchange part 14 ... Exhaust tube 15 ... Temperature switch 16 ... Water level switch 17 ... Control panel DESCRIPTION OF SYMBOLS 18 ... Power supply panel 19 ... Heating prevention switch 20 ... Thermometer 21 ... Wind pressure switch 22 ... Exhaust gas temperature switch 23 ... Housing 24 ... Fan 25 ... Water level meter 100 ... Liquefied fuel gas vaporizer

Claims (3)

An introduction channel for introducing liquid-phase gas fuel;
An evaporator for vaporizing the liquid-phase gas fuel introduced through the introduction flow path by heating with a heating source;
A discharge passage for discharging the fuel gas vaporized by the evaporator;
A liquefied fuel gas vaporizer comprising a control panel for controlling the heating source,
A housing for housing the introduction flow path, the evaporator, the discharge flow path, and the control panel;
An inside air exhaust fan that is provided in the housing and exhausts the gas inside the housing to the outside of the housing ,
The outside air introduction fan for introducing the gas outside the housing into the housing to increase the inside pressure of the housing is not provided, and the inside air exhaust fan discharges the gas inside the housing by a predetermined amount outside the housing.
The liquefied fuel gas vaporizer characterized by the above-mentioned. The liquefied fuel gas vaporizer according to claim 1, wherein the inside air discharge fan discharges a gas of 5 times or more the inside volume of the housing per hour to the outside of the housing. The said control panel detects abnormality of the said inside air exhaust fan when the output pulse width of the fan motor at the time of the said inside air exhaust fan operation | movement is more than predetermined width. The liquefied fuel gas vaporizer described in 1.

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