JP2001012692A - Liquefied gas evaporating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the safety by providing an exhaust heating prevention switch for detecting the temperature upper limit of exhaust combustion gas. SOLUTION: This device comprises a heating means 12 for combusting fuel by supplying fuel and air thereto, air supplying means 6, 7 for supplying the air to the heating means 12, a heat medium liquid tank 51 having a combustion chamber 52 for arranging the heating means 12 to retain a heat medium liquid (w) to be heated by the combustion heat generated in the combustion chamber 52, a heat exchanging means 53 provided within the heat medium liquid tank 51 to evaporate a liquefied gas by the heat of the heat medium liquid (w), an inner pressure vessel 9 having control apparatuses 16, 17, 18 for controlling the fuel in the inner part and pressurizable to the pressure exceeding the atmospheric pressure by supplying air thereto, and an air chamber 11 communication with the inner pressure vessel 9 to collect and supply the air to the heating means 12. Further, an exhaust heating prevention switch 32 for detecting the temperature for the combustion gas and stopping the operation of the device when the temperature is a set value or more is mounted on an exhaust cylinder 59 for exhausting a combustion exhaust gas Gg within the combustion chamber 52.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquefied gas evaporator for heating a liquid liquefied petroleum gas (LP gas) with a heat carrier liquid to evaporate it.

[0002]

2. Description of the Related Art FIG. 4 is a schematic structural view of a conventional liquefied gas evaporator. The conventional liquefied gas evaporator 60 includes a heat source device 61 for heating the heating medium water w, a liquefied gas,
For example, liquefied petroleum liquid (LP liquid) which is liquid of liquefied petroleum gas
L is heated with the heating medium water w to evaporate L into LP gas Gp
And a PG evaporator 74.

[0003] The heat source unit 61 heats the heating medium water w by burning the combustion gas Gf as fuel with air. The combustion gas Gf is supplied to the burner 65 via the solenoid valve 62 and the regulator 63. The combustion air Ga is supplied to the burner 65 through the air chamber 67 by the blower 66. The hot water temperature sensor 69 is connected to the main body 61a of the heat source device.
The temperature of the heat transfer water w is detected, and the signal is input to the heat source device control panel 68. The heat source device control panel 68 receives the temperature signal of the heating medium water w, and receives the electromagnetic valve 62, the burner 65 and the blower 6.
6 is controlled. Further, the main body 61a of the heat source device is provided with an empty-fire prevention device 71 for preventing empty-heating, and a signal thereof is also input to the heat-source device control panel 68.

The LPG evaporator 74 has an evaporator body 74.
a, the LP liquid L flowing from the LP liquid inlet 76 at one end of the heat exchanger 75 evaporates by receiving the heat of the heat transfer water w sent by the hot water circulation pump 72. ,
The gas flows out from the LP gas outlet 77 at the other end of the heat exchanger 75 as the LP gas Gp. The heat transfer water w whose temperature has been reduced by the heat exchange in the heat exchanger 75 is returned to the heat source device 61 through the circulation hot water pipe 73.

[0005]

The use of fire and electricity is limited around the LPG evaporator 74 because LP gas may stay in an abnormal state (dangerous area 58 indicated by a broken line).

For this reason, in the liquefied gas evaporator 60, it is necessary to keep the heat source device 61 at a certain distance from the LPG evaporator 74 (the non-dangerous area 57 shown by the two-dot chain line).
A hot water pipe 73 for circulating the heat medium water w is provided between the heat source unit 61 and the evaporator 74, and the heat medium water w must be constantly circulated by the hot water circulation pump 72. There is a problem that the electricity bill is large and the space and energy saving properties are lacking.

The applicant of the present invention has proposed a liquefied gas evaporator which can efficiently and safely evaporate a liquefied gas liquid with a small space and energy by coping with such a problem (Japanese Patent Application No. 10-279625). issue).

The present invention relates to the improvement of the above-mentioned prior application, and in particular, by providing an exhaust heating prevention switch for detecting the upper limit of the temperature of the combustion exhaust gas, liquefied gas evaporation with improved safety. It is intended to provide a device.

[0009]

In order to achieve the above object, the invention according to claim 1 comprises heating means for supplying and burning fuel and air, and air supply means for supplying the air to the heating means. A heating medium tank having a combustion chamber in which the heating means is arranged, and holding a heating medium liquid heated by combustion heat generated in the combustion chamber; and a heat medium liquid provided in the heating medium liquid tank. A liquefied gas evaporator, comprising: a heat exchange means for evaporating a liquefied gas liquid at a pressure; a control device for controlling supply of the fuel to the heating means; and an air chamber for storing the air and supplying the air to the heating means. An exhaust gas exhaust exhaust switch for exhausting combustion exhaust gas in the combustion chamber is provided with an exhaust heat prevention switch for detecting a temperature of the combustion exhaust gas and stopping operation of the device when the temperature of the exhaust gas exceeds a set value. It is characterized by the following.

Therefore, according to the first aspect of the present invention, when the temperature of the combustion exhaust gas is abnormal due to a decrease in the level of the heat transfer water or a malfunction of the hot water temperature sensor, the blower, the solenoid valve, or the like, the operation of the apparatus is stopped immediately. In addition to ensuring safety, failure of the hot water temperature sensor and the blower itself can be detected by detecting the exhaust heat prevention switch. Furthermore, since the temperature of the combustion exhaust gas is detected at the final stage to detect an abnormality, a conventionally required water level detector and overheat preventer for the heat transfer water are not required, and the number of parts can be reduced.

According to a second aspect of the present invention, there is provided the liquefied gas evaporator according to the first aspect, wherein the control device supplies the air provided in communication with the air chamber to reduce the atmospheric pressure. It is characterized in that it is provided inside an internal pressure vessel that can be pressurized to a pressure exceeding it.

For this reason, in the second aspect of the present invention, since the pressure inside the internal pressure vessel is higher than the atmospheric pressure,
Even if the P gas stays around the internal pressure vessel or the heat transfer fluid tank, the LP gas does not flow into the internal pressure vessel, thereby protecting the control device in the internal pressure vessel.

According to a third aspect of the present invention, there is provided the liquefied gas evaporator according to the first aspect, wherein the control device is of an explosion-proof type and provided so as to be exposed to the outside of the air chamber. It is characterized by having.

Therefore, according to the third aspect of the invention, maintenance of the control device is facilitated.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. The same members or those having the same functions as those in FIG. 4 are denoted by the same reference numerals.

FIG. 1 is a schematic structural view showing an embodiment of a liquefied gas evaporator according to the present invention. The liquefied gas evaporator 1 of the present embodiment includes a burner 12 as a heating unit for supplying and burning the combustion gas Gf and the combustion air Ga as a fuel, and an air supply for supplying the combustion air Ga to the burner 12. An explosion-proof blower 6 and a suction pipe 7 are provided as means.

Further, the combustion chamber 5 in which the burner 12 is disposed
A hot water tank (heat medium liquid tank) 51 for holding a heat medium water (heat medium liquid) w heated by combustion heat generated in the combustion chamber 52
And a heat exchanger 53 which is provided in the hot water tank 51 and is a heat exchange means for evaporating the LP liquid L by the heat of the heat medium water w. In this heat exchanger 53, the LP liquid inlet 54 at one end
The LP liquid L flowing in from the evaporator receives the heat of the heat medium water w, evaporates, and flows out as the LP gas Gp from the LP gas outlet 55 at the other end.

An internal pressure vessel 9 is connected to the outlet side of the blower 6. The internal pressure vessel 9 is connected to the air chamber 11 through a ventilation pipe 13.
The air supplied from the ventilation pipe 13 to the air chamber 11 is supplied to the burner 12 as combustion air.

Here, the suction port 8 of the suction pipe 7 of the blower 6 opens to a non-dangerous area 57, from which combustion air Ga is introduced. Further, the combustion gas Gf is introduced through the suction pipe 15. The combustion gas Gf and the combustion air Ga supplied to the burner 12 are injected into the combustion chamber 52 and burned, and the generated combustion gas Gg is discharged upward through the exhaust pipe 59. The above non-dangerous area 57
Is generally 8 m or more in horizontal distance from the liquefied gas evaporator 1 or 3 m or more above the ground, but is not limited to this position.

A combustion gas G is provided inside 9a of the internal pressure vessel 9.
Electromagnetic valves 16 and 17 and a regulator 18 which are control devices for controlling f are provided. Specifically, this solenoid valve 1
6, 17 and the adjuster 18 are provided on a supply pipe 15 which communicates with the burner 12 and is drawn out of the air chamber 11 and penetrates the internal pressure vessel 9 and supplies the combustion gas Gf. The internal pressure container 9 is capable of supplying combustion air Ga to be pressurized to a pressure exceeding atmospheric pressure. Further, it is confirmed that the pressure of the internal pressure container 9 has exceeded the atmospheric pressure,
A control device 19 is provided which starts energization of the burners 6, 17 and the burner 12, and causes the burner 12 to perform combustion.

The control device 19 includes a blower control panel 28
And a hot water temperature sensor 31 with a hot water tank 51 attached.
A pressure switch 20 for detecting the pressure in the internal pressure container 9;
And an exhaust heat prevention switch 32 attached to the exhaust pipe 59. Then, as described above, the control device 19 confirms that the pressure in the internal pressure container 9 has exceeded the atmospheric pressure, and more preferably, the control devices 16, 17, 18 and The power supply to the burner 12 is started, and the burner 12 burns. In addition,
Blower 6, hot water temperature sensor 31, pressure switch 20,
It is preferable that the blower control panel 28 and the like be of an explosion-proof type.

When the temperature of the heat medium water w is low and the combustion of the burner 12 is required, the blower 6 sends the combustion air Ga from the non-dangerous place 57 to the internal pressure container 9 through the suction pipe 7. Since the internal pressure vessel 9 is communicated with the air chamber 11 through the ventilation pipe 13, the combustion air Ga pressure-fed from the blower 6 flows into the combustion chamber 52 of the burner. At this time, if it is confirmed that the pressure in the interior 9a of the internal pressure container 9 is equal to or higher than the atmospheric pressure + ΔP (pressure exceeding the atmospheric pressure) and is maintained for the above-described predetermined time, the burner 12 is ignited and the combustion is performed. Is started.

Since the interior 9a of the internal pressure vessel 9 has a pressure exceeding the atmospheric pressure, the LP gas must be supplied to the internal pressure vessel 9 or the hot water tank 5
The LP gas does not flow into the internal pressure container 9 even if it stays around the periphery of the pressure vessel 1. Note that the hot water temperature sensor 31, the exhaust heat prevention switch 32, and the control devices 16, 17, 18
Are explosion-proof wiring (each black mark of reference numeral 26).

For some reason, L
Even if the P gas enters, it is scavenged by clean combustion air Ga introduced from the non-hazardous area 57 and then the internal pressure vessel 9
There is no danger because the power supply to the control devices 16, 17, and 18 is started and the burner 12 is ignited.

Next, the operation of the exhaust heat prevention switch 32 when an abnormality is detected will be described with reference to the flowchart of FIG.

When the temperature of the combustion exhaust gas Gg passing through the exhaust pipe 59 is normal, the exhaust heat prevention switch 32 is turned off.
F, it is determined that it is normal in step S1, and if it is determined in step S2 that the hot water temperature is equal to or less than the set value of the hot water temperature sensor 31, the operation of the blower 6 is started (step S3), and the internal pressure vessel is started in step S4. It is determined whether or not the pressure in the pressure 9 is normal. If the pressure is normal, the power supply to the internal pressure vessel 9 is started (step S5), and the combustion by the burner 12 is started (step S6). In steps S2 and S4,
If it is determined that there is an abnormality (more than the set value), the process returns to step S1, and the above operation is repeated.

When the level of the heat transfer water w in the exhaust pipe 59 decreases, the contact area (heat transfer area) between the heat transfer water w and the wall surface of the combustion chamber 52 decreases, and heat exchange between the heat transfer water w and the combustion gas occurs. Since the amount decreases, the temperature of the combustion exhaust gas in the exhaust stack 59 increases.
The temperature of the combustion exhaust gas also increases due to a failure of the hot water temperature sensor 31, a failure of the blower 6, the solenoid valves 16, 17, and the like. This combustion exhaust gas temperature has a certain set value (for example,
When the temperature exceeds 250 ° C.), the exhaust heat prevention switch 32 is turned on, it is determined that an abnormality has occurred (step S1), and the operation is stopped abnormally, that is, the operation of the entire apparatus is stopped.
The power supply to the inside is stopped, and the power supply to the solenoid valves 16, 17 and the adjustment valve 18 is stopped to close them (step S7).

As described above, in the liquefied gas evaporator 1 of the present embodiment, the exhaust heating prevention switch 32 is attached to the exhaust pipe 59 for exhausting the combustion gas in the combustion chamber 52, and the temperature of the combustion gas is equal to or higher than the set value. Since the operation of the device is stopped when the condition becomes, various abnormalities of the device, for example, a decrease in the level of the heat transfer water w, a failure of the hot water temperature sensor 31, a failure of the blower 6, the electromagnetic valves 16, 17 and the like, and the like. As soon as the temperature of the exhaust combustion gas rises, the operation of the device is stopped, safety can be ensured, and failure of the hot water temperature sensor 31 and the blower 6 itself can be found by detecting the exhaust heat prevention switch 32.

Further, since the above-mentioned abnormality is detected by detecting the temperature of the combustion exhaust gas at the final stage, a water level detector for the heat transfer water w of the hot water tank 51 and an overheat prevention device which are conventionally required become unnecessary. The number of parts can be reduced.

FIG. 3 shows a modification of the above embodiment. This modification is different from the first embodiment in that the control device is configured as an explosion-proof type and is provided so as to be exposed not to the inside of the internal pressure container 9 but to the outside of the air chamber 11. The configuration is the same as that of the above-described embodiment.

Specifically, the control device is an explosion-proof solenoid valve 16A provided in a supply pipe 15 that is led out of the air chamber 11 and supplies the combustion gas Gf to the burner 12.
And an adjuster 14 for adjusting the flow rate of the combustion gas Gf. In this modification, since the internal pressure container 9 is not provided, the pressure switch 20 is provided in the air chamber 11. After confirming that the pressures in the air chamber 11 and the combustion chamber 52 have exceeded the atmospheric pressure by the pressure switch 20, the control device 19 controls the solenoid valve 16A, the regulator 14, and the burner after a predetermined period of time. 12 and the burner 12 burns.

In this modified example, it is needless to say that the same operation and effect as those of the above-described embodiment can be obtained. In addition, since the control devices 16A and 14 are provided to be exposed outside the air chamber 11, they are provided. There is an advantage that maintenance of these control devices 16A and 16 becomes easy.

[0033]

As described in detail above, according to the first aspect of the present invention, the exhaust gas heating switch is attached to the exhaust pipe to detect the temperature of the combustion gas. As soon as the temperature of the combustion exhaust gas rises abnormally due to a drop or a malfunction of the hot water temperature sensor, the blower, the solenoid valve, etc., the operation of the device is stopped immediately, safety can be ensured, and a failure of the hot water temperature sensor and the blower itself can be found.

In addition, there is no need for a water level detector or overheat prevention device for the heating medium in the hot water tank, and the number of parts can be reduced.

According to the second aspect of the invention, in addition to the effect of the first aspect, the control device is provided in the internal pressure vessel into which the LP gas does not flow. And the safety of the installation environment of the control device can be ensured.

According to the third aspect of the present invention, in addition to the effects of the first aspect of the present invention, since the control device is provided so as to be exposed to the outside of the air chamber, maintenance of the control device is facilitated. Thereby, accurate operation of the control device can be ensured.

[Brief description of the drawings]

FIG. 1 is a schematic structural view showing one embodiment of a liquefied gas evaporator according to the present invention.

FIG. 2 is a flowchart showing the operation of the present invention.

FIG. 3 is a schematic structural view showing a modification of the liquefied gas evaporator of FIG.

FIG. 4 is a schematic structural view of a liquefied gas evaporator according to the related art.

[Explanation of symbols]

 Reference Signs List 1 liquefied gas evaporator 6 blower (air supply means) 7 suction pipe (air supply means) 9 internal pressure vessel 11 air chamber 12 burner (heating means) 16, 17, 18 control equipment 16A, 14 control equipment 32 exhaust heat prevention switch 51 Heat medium liquid tank 52 Combustion chamber 53 Heat exchanger (Heat exchange means) 59 Exhaust tube Gg Combustion exhaust gas w Heat medium water (Heat medium liquid)

Claims (3)

[Claims] 1. Combustion generated in a combustion chamber having heating means for supplying fuel and air for combustion, air supply means for supplying the air to the heating means, and a combustion chamber in which the heating means is disposed. A heat medium liquid tank for holding a heat medium liquid to be heated by heat,
A heat exchange means provided in the heat medium liquid tank for evaporating the liquefied gas liquid by the heat of the heat medium liquid; a control device for controlling supply of the fuel to the heating means; A liquefied gas evaporator, comprising: an air chamber that supplies the gas to the means; a liquefied gas evaporator comprising: an exhaust pipe configured to exhaust the combustion exhaust gas in the combustion chamber; A liquefied gas evaporator, which is provided with an exhaust heat prevention switch for stopping the operation of the device when the liquefied gas evaporates. 2. The liquefied gas evaporator according to claim 1, wherein the control device supplies the air provided in communication with the air chamber and is capable of increasing the internal pressure to a pressure exceeding atmospheric pressure. A liquefied gas evaporator, which is provided inside a container. 3. The liquefied gas evaporator according to claim 1, wherein the control device is of an explosion-proof type and is provided so as to be exposed outside the air chamber. Evaporator.