JP2000346339A - Liquiefied gas evaporating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a fault of an equipment due to a reverse flow of an atmosphere by providing a post-purging means for scavenging a combustion chamber by operating a blower for a predetermined time after a heating means is stopped. SOLUTION: When a temperature of a heating medium water W becomes higher than a set temperature of a warm water temperature sensor 23 during operating of the apparatus, a power source of the apparatus is turned OFF by a controller 19, and the apparatus is stopped. Simultaneously, when the operation is stopped, solenoid valves 16, 17 are closed, and a combustion is stopped. Thereafter, a blower 6 is continuously operated for a certain time (t), scavenged and then stopped. The scavenging of this time (t) is called 'post- purging'. An atmosphere is reversely fed from an air outlet of an exhaust cylinder 59 by the post-purging, introduced into a combustion chamber 52. Then, high-temperature air in the chamber 52 flows into an internal pressure container 9, thereby preventing a phenomenon of causing faults of the equipments 16, 17, 18 or the like to be controlled. The time (t) of the post-purging may be short e.g. about 20 s.

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. 3 is a schematic structural view of a conventional liquefied gas evaporating apparatus. 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 uses the combustion gas Gf as a fuel and burns it together with the air Ga to heat the heating medium water w. 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 6 of the heat source device.
The temperature of the heat transfer water w in 1a 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 controls the electromagnetic valve 62, the burner 65, and the blower 66. Further, the main body 61a of the heat source device is provided with an empty-fire prevention device 71 for preventing empty-heating, and its signal 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 unit 61 at a certain distance from the LPG evaporator 74 (the non-dangerous area 57 shown by a 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 petroleum gas liquid with a small space and energy in order to cope with such a problem (Japanese Patent Application No. Hei 10-1998). 279625).

The present invention relates to an improvement of the above-mentioned prior application, and in particular, to provide a liquefied gas evaporator in which a post-purge of a combustion chamber is performed to prevent equipment failure due to backflow of outside air. With the goal.

[0009]

In order to achieve the above object, the invention according to claim 1 comprises a heating means for supplying fuel and air for combustion, a blower for supplying the air to the heating means, A heat medium liquid tank that has a combustion chamber in which a heating means is disposed and holds a heat medium liquid that is heated by combustion heat generated in the combustion chamber; A heat exchange means for evaporating the gas liquid, an internal pressure container provided with a control device for controlling the fuel therein and capable of supplying the air and pressurizing to a pressure exceeding atmospheric pressure, and communicating with the internal pressure container and the air A liquefied gas evaporator comprising: an air chamber for storing and supplying air to the heating means, wherein after the heating means is stopped, the blower is operated for a predetermined time to scavenge the combustion chamber. It is characterized by having.

Therefore, in the present invention, even if a backflow from the exhaust stack occurs, the inside of the internal pressure vessel does not become hot, thereby preventing the failure of the control device and reducing the humidity in the combustion chamber to prevent corrosion. .

[0011]

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. 3 are denoted by the same reference numerals.

FIG. 1 is a schematic structural view showing one 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, an air chamber 11 is connected to the internal pressure vessel 9, and air supplied from the internal pressure vessel 9 to the air chamber 11 is supplied to the burner 12 as combustion air. Is done.

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 exhaust gas Gg is discharged from the exhaust pipe 5.
It is discharged upward through 9.

The exhaust pipe 59 is connected to the non-dangerous area 60 by piping. Thereby, the combustion exhaust gas Gg is released to the non-dangerous place 60 and is prevented from being released to the dangerous place 58. A heat insulating material may be provided on the surface of the exhaust pipe 59 as needed. The non-dangerous locations 57 and 60 are generally located at a distance of 8 m or more horizontally from the liquefied gas evaporator 1 or at a height of 3 m or more from the ground, but are not limited to these positions.

In the interior 9a of the internal pressure vessel 9, there are provided solenoid valves 16, 17 and a regulator 18, which are control devices for controlling 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, after confirming that the pressure of the internal pressure vessel 9 has exceeded the atmospheric pressure, the control device 1 that starts energizing the solenoid valves 16 and 17 and the burner 12 and causes the burner 12 to perform combustion.
9 is provided.

The control device 19 includes a blower control panel 28
Hot water temperature sensor 23 and overheat prevention device 31,
And a pressure switch 20. And the control device 19
Confirms that the pressure in the internal pressure vessel 9 has exceeded the atmospheric pressure as described above, and more preferably starts energizing the control devices 16, 17, 18 and the burner 12 after a predetermined period of time has elapsed. Then, the burner 12 burns. Blower 6, hot water temperature sensor 23, overheat prevention device 3
1, the pressure switch 20, the blower control panel 28, etc. are of 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 container 9 is communicated with the air chamber 11, 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 inner portion 9a of the internal pressure container 9 is equal to or higher than the atmospheric pressure of 10 △ P (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 is at a pressure exceeding the atmospheric pressure, the LP gas should be supplied to the internal pressure vessel 9 or the hot water tank 5 by any chance.
The LP gas does not flow into the internal pressure container 9 even if it stays around the periphery of the pressure vessel 1. The electrical components of the control device are explosion-proof wiring (each black mark 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 essential points of the operation will be described with reference to FIG.

First, when the power of the apparatus is turned on and the operation is started, the pressure in the internal pressure container 9 is increased with a slight delay, the pressure switch 20 is turned on, and the blower 6 is turned on at the same time as the power is turned on.
N, the supply of the combustion air Ga is started, and the solenoid valves 16 and 1 are started.
When 7 is opened, the combustion gas Gf is sent to the burner 12, and the combustion starts by ignition.

If the temperature of the heat transfer water w becomes higher than the temperature set by the hot water temperature sensor 23 during the operation of the apparatus, the controller 1
The power of the apparatus is turned off by 9 and the operation of the apparatus is stopped. At the same time as the operation is stopped, the solenoid valves 16 and 17 are closed,
Although the combustion stops, the blower 6 continues to operate for a certain time t and stops after scavenging (this scavenging at time t is called post-purge).

After the combustion has stopped, if left as it is,
The outside air flows backward from the outlet 59 a of the exhaust pipe 59 into the combustion chamber 52, and the high-temperature air in the combustion chamber 52 flows into the internal pressure vessel 9.
And cause a failure of the control devices 16, 17, 18 and the like. By cooling the residual heat of the combustion chamber 52 by the post-purge, such a phenomenon can be prevented. The post-purge time t may be as short as about 20 seconds.
Such a post-purge operation and time setting can be performed by the control device 19.

As described above, in the liquefied gas evaporator 1 of the present embodiment, after the combustion in the burner 12 is stopped, the blower 6
Is operated for a predetermined time to perform post-purge to cool the combustion chamber 52 immediately after the combustion is stopped.
Even if the backflow from 9 occurs, the inside of the internal pressure vessel 9 does not become hot, and even if dew condensation occurs in the combustion chamber 52, the humidity of the combustion chamber 52 is also reduced by post-purge. Corrosion can also be prevented.

Further, by performing post-purging,
When the next combustion request is made, the pre-purge time (preliminary scavenging of the combustion chamber 52) is shortened, and the operation stop time is shortened accordingly, so that the follow-up of the temperature control of the heat transfer water w is improved. I do.

[0028]

As described above in detail, according to the present invention, after the combustion is stopped, the blower is operated for a predetermined time to perform the post-purge, so that the combustion chamber immediately after the stop of the combustion is cooled and the exhaust gas is discharged. Even if the backflow from the cylinder occurs, the inside of the internal pressure vessel does not become high temperature, and the failure of the control device is prevented, and the humidity in the combustion chamber is reduced, so that the corrosion in the combustion chamber can be prevented.

Further, according to the present invention, when the next combustion request is made after the stop of the combustion, the pre-purge time is shortened and the operation stop time is shortened accordingly, so that the followability of the temperature control of the heat transfer water is improved. improves.

[Brief description of the drawings]

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

FIG. 2 is an explanatory diagram of a control operation according to the present invention.

FIG. 3 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 9 internal pressure vessel 11 air chamber 12 burner (heating means) 16, 17 solenoid valve (control device) 18 regulator (control device) 19 controller (postpurge means) 51 heating medium liquid tank 52 combustion Room 53 Heat exchanger (heat exchange means) w Heat medium water (heat medium liquid)

Claims (1)

[Claims] 1. A heating means for supplying and burning fuel and air, a blower for supplying the air to the heating means, and a combustion chamber in which the heating means is disposed, wherein a combustion heat generated in the combustion chamber is used. A heat medium liquid tank for holding a heat medium liquid to be heated, heat exchange means provided in the heat medium liquid tank for evaporating a liquefied gas liquid by heat of the heat medium liquid, and a control device for controlling the fuel are internally provided. A liquefied gas evaporator, comprising: an internal pressure vessel provided at a pressure chamber capable of supplying the air to pressurize to a pressure exceeding atmospheric pressure; and an air chamber communicating with the internal pressure vessel and storing the air and supplying the air to the heating means. A liquefied gas evaporator, comprising: a post-purge unit for operating the blower for a predetermined time after the heating unit is stopped to scavenge the combustion chamber.