JPH0689879B2 - Air temperature / hot water combined LPG air gas production plant - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a liquefied propane gas, liquefied butane gas, or other liquefied petroleum gas (LPG) that is vaporized and mixed with air to produce propane air gas or butane air gas (the present specification). In the book "LP
G air gas ". ) Is manufactured, and in particular, it relates to an air-temperature / hot-water LPG air gas production plant equipped with an air-temperature / hot-water vaporizer that can be used even in cold regions or in extremely cold seasons.

2. Description of the Related Art The applicant of the present application, as disclosed in Japanese Patent Laid-Open No. 61-180099, vaporizes liquefied propane gas in an air-temperature type forced vaporizer and mixes it with air to produce 13A propane air gas. A manufacturing plant was proposed.

The air-heated forced vaporizer used in this 13A propane air gas production plant has a finned heat transfer tube made of aluminum with a high heat transfer efficiency similar to that of liquid oxygen or liquid nitrogen. heat transfer coefficient: 25.3kg / m ³ · h
liquefied propane gas produced in the vaporizer, the liquefied propane gas flowing into the vaporizer lowers the boiling point of the liquefied propane gas by reducing the pressure at the liquid inlet portion of the vaporizer, that is, 1 kg / cm 2.
^In the case of 2.G, it is set to about -27 ° C, and a temperature difference from the atmospheric temperature is created.
It has a structure in which it is gasified by a heat transfer tube with fins.

As described above, the air-temperature type forced vaporizer uses the atmospheric temperature as a heat source and has a structure for evaporating the liquefied propane gas due to the temperature difference between the atmospheric temperature and the liquid temperature of the liquefied propane gas.
This 13A propane air gas production plant has a feature that the initial cost for the heat source equipment for evaporation and the running cost of the equipment are zero, and thereby the city gas can be produced and supplied at an extremely low cost.

However, in the 13A propane air gas production plant by the present applicant, the design capacity of the air temperature type forced vaporizer has an atmospheric temperature of −8 ° C. or higher in consideration of the initial cost of the facility, It is standard for 4 hours of continuous operation in cloudy and windless conditions, so that it may be difficult or, in some cases, impossible to use in cold regions or severe cold seasons.

For example, in Japan, for example, in the area south of Kanto, the air-cooled forced vaporizer with the above design specifications is sufficient, but in other areas the vaporization capacity in winter will decline. Become. According to the result of the applicant's experimental research, the northeastern part of Kanto is the northern limit.

Also, even if it is south of Kanto, frost on the carburetor will be severe if the plant continues to operate continuously, so a spare air-temperature type forced carburetor for switching is required, and the initial cost becomes high. .

If a separate hot water vaporizer is installed as a measure against cold regions or severe cold seasons, the initial cost will be further increased.

Furthermore, in Japan, as a city gas production plant,
Attempts have also been made to produce butane air gas using liquefied butane gas as a raw material.

Liquefied butane used in the butane air gas plant has a high boiling point, that is, it is about 15 ° C. in the case of 1 kg / cm ² · G,
It is necessary to vaporize with a vaporizer that uses electricity, hot water or steam as a heat source, and the use of a conventional air temperature type forced vaporizer such as that used in the above-mentioned 13A propane air gas production plant Was impossible.

A main object of the present invention is generally air temperature type in summer, hot water type in winter, etc., and switching operation is possible depending on climatic conditions etc., and it is also suitable in cold regions or severe cold season.
(EN) An air temperature / hot water combined LPG air gas production plant equipped with an air temperature / hot water combined evaporation device capable of vaporizing LPG and capable of efficiently producing LPG air gas.

Another object of the present invention is to increase vaporization capacity and evaporation capacity, and to efficiently remove frost formed on a device due to continuous operation and the like, which requires a spare vaporizer for switching. Equipped with an air / warm water type vaporizer that never happens,
Air temperature that can efficiently produce LPG air gas
It is to provide a hot water combined LPG air gas production plant.

Means for Solving the Problems The above-mentioned objects are achieved by the air-temperature / hot-water dual-use LPG air gas production plant according to the present invention. In summary, the present invention vaporizes liquefied petroleum gas, which is liquefied propane gas or liquefied butane gas, in an air temperature / hot water combined vaporizer, and mixes the vaporized liquefied petroleum gas with air to produce LPG air gas. In the above-mentioned plant, the air-heated / hot-water vaporizer comprises a supply-side manifold, a discharge-side manifold, a plurality of transmissions connected at one end to the supply-side manifold and at the other end to the discharge-side manifold. A heat tube, the supply-side manifold, a liquefied petroleum gas pipe connected to one end of each of the heat transfer tubes, and a jacket pipe arranged to surround the outside of the liquefied petroleum gas pipe In a dual pipe structure, liquefied petroleum gas is supplied to the liquefied petroleum gas pipe, and hot water is supplied to the jacket pipe. That. Preferably, the liquefied petroleum gas pipe is provided with an annular baffle plate, and the hot water is water mixed with an antifreeze liquid.

Example Next, the air-temperature / hot-water LPG air gas production plant according to the present invention, and particularly the air-temperature / hot-water vaporization apparatus suitably used in this production plant will be described in more detail with reference to the drawings.

FIG. 1 illustrates an embodiment of a vaporizer for combined use of air temperature and hot water, which constitutes a main part of the present invention. According to the present embodiment, the air-heated / hot-water carburetor 1 has a supply side manifold 2 and a discharge side manifold 4, and a heat transfer tube 6 is provided between the supply side manifold 2 and the discharge side manifold 4. Are connected in large numbers. Further, in order to improve the heat transfer (heat absorption) effect of the heat transfer tube 6, heat transfer fins 8 are arranged around the heat transfer tube 6.

Further in accordance with the present invention, as best understood with reference also to FIGS. 2 and 3, the supply manifold 2 comprises:
Liquefied petroleum gas pipes (hereinafter referred to as "LP
It is called G tube. ) 21 and a jacket tube 22 surrounding the outside of the LPG tube 21 and having a double structure.

One end 23 of the LPG pipe 21 projects from the jacket pipe 22,
Connected to a PG storage tank (not shown) but with the other end 24
Is sealed and located within jacket tube 22. Also, LP
The G pipe 21 is connected to the inlet end of the heat transfer tube 6 in the jacket pipe 22 as described above, and thus the LP pipe
The LPG fed into the G pipe 21 flows into the heat transfer tube 6 and then flows to the discharge side manifold 4 to which the other end of the heat transfer tube 6 is connected.

An inlet 25 is formed at one end of the outer jacket tube 22,
An outlet 26 is provided at the other end. The inlet 25 is connected to the warm water storage tank 31 of the warm water supply source 30 via a supply line L ₁ equipped with a pump P, and the outlet 26 is connected to the warm water supply source 30 via a return line L _2.
Is returned to. Therefore, the hot water from the hot water storage tank 31 is supplied to the inlet 25 of the jacket pipe 22 by the pump P via the supply pipe L _1.
Is then supplied to the outlet pipe 26 while exchanging heat with the LPG passing through the LPG pipe 21 in the jacket pipe 22, and returned to the hot water storage tank via the return pipe line L ₂ .

In addition, a baffle plate 27 is annularly formed around the LPG pipe 21.
Are preferably provided at appropriate locations. In general, the hot water flowing in the jacket pipe 22 is in a state close to static water because of frictional resistance where it contacts the outer surface of the LPG pipe 21,
It will reduce the thermal conductivity. This is caused by the laminar flow of warm water flowing in the pipe, which can be prevented by making it turbulent. In order to generate turbulent flow, it is necessary to make the velocity of the hot water flowing in the pipe above the critical velocity, but this requires a considerable amount of power and the retention time of the hot water in the pipe is shortened. As a result, the heat exchange efficiency decreases.

On the other hand, according to the present invention, the baffle plate
By providing 27, turbulent flow can be generated in the pipe without increasing the flow velocity, and heat transfer efficiency can be increased.

In this embodiment, the hot water storage tank 31 of the hot water supply source 30 is a hot water storage type hot water boiler, and a heating source such as a boiler (not shown).
Is attached. Therefore, the warm water that is returned from the jacket pipe 22 to the warm water storage tank 31 through the return pipe line L ₂ is heated by the temperature detecting means 32 such as a thermistor arranged at an appropriate position in the return pipe line L _2. The temperature is monitored, and the combustion of the boiler is controlled by the difference from the temperature set by the driver in advance, and hot water of a predetermined temperature, for example, hot water of 60 ° C to 80 ° C is constantly supplied to the jacket pipe 22. It The amount of hot water supplied into the jacket pipe 22 may be variously selected depending on the desired vaporization capacity of the air / hot water vaporizer.

Further, the hot water supply source 30 is provided with a level detector 33 such as a level oscillator in order to keep the water level of the hot water in the hot water storage tank 31 constant at all times, and the water supply line L is supplied by the signal from the level detector 33. _{By controlling the third} valve, that is, the pneumatic actuator valve 34, the amount of water supplied to the hot water storage tank 31 via the water supply line L ₃ is adjusted.

In the present invention, the liquid used as warm water may be ordinary water, but antifreeze mixed water in which an antifreeze is mixed is preferable. The reason is as follows.

That is, for example, when liquefied propane gas is used as the raw material LPG, the LPG pipe 2 of the vaporizer 1 for both air temperature and hot water
Liquefied propane gas at a low temperature close to -42 ° C will flow into 1. Therefore, for example, in the jacket tube 22, for example, 60
Even if warm water of about 80 ° C to 80 ° C is flowed in at a flow rate of 0.2 to 0.4 / min, the inside of the LPG pipe 21 is cooled due to the LPG close to -42 ° C and may be frozen. Particularly, as the center of the warm water flowing in the jacket pipe 22 approaches the LPG pipe 21, the flow velocity decreases due to frictional resistance.
There is a possibility that it will be near zero on the outer surface of the water, and it will be in the state of still water, which further increases the risk of cooling and freezing. Therefore, in order to prevent freezing even if the inflow of warm water is stopped, it is extremely preferable to mix the antifreeze liquid, or in some cases it is essential.

Ethylene glycol as the main ingredient of antifreeze is 30 ~
Commercially available antifreeze containing 60% can be used. The amount of antifreeze will usually be water: antifreeze = 10: 2 to 3 although it varies depending on the conditions or region where the vaporizer is used. .

The operation of the air-heated / hot-water type vaporizer having the above structure will be described below.

For example, in the 13A propane air gas production plant for producing 13A propane air gas by mixing liquefied propane gas as a raw material and vaporized propane gas and air, the vaporizer 1 for both air temperature and hot water according to the present invention 1 If, for example, in the summer, the air temperature / warm water combined type vaporizer 1 is operated continuously for 4 hours in an atmospheric temperature of −8 ° C. or higher, cloudy and no wind, hot water is circulated in the jacket pipe 22. There is no such thing. Therefore, the air-temperature / hot-water type vaporizer 1 is
It simply acts as an air temperature vaporizer. In other words, the liquefied propane gas (LP
G) flows from the supply side manifold 2, that is, the LPG pipe 21 to the discharge side manifold 4 via the heat transfer tube 6. At this time, the liquefied propane gas is vaporized by the action of the heat transfer tube 6 and the heat transfer fins 8 and becomes propane gas (G).

On the other hand, when it is used in a severe cold season when the atmospheric temperature becomes lower than -8 ° C, or when it is used in a cold district, the warm water L of a predetermined temperature is supplied from the warm water storage tank 31 of the warm water supply source 30 to the circulation pump P.
By means of the supply line L ₁ into the jacket pipe 22 of the supply-side manifold 2.

Liquefied propane gas (LPG) is delivered to the supply-side manifold 2, that is, the LPG pipe 21, and in the supply-side manifold 2, heat exchange with the hot water flowing in the jacket pipe 22 is performed, whereby Be vaporized. The vaporized propane gas (G) flows to the discharge side manifold 4 via the heat transfer tube 6. Therefore, in general, the liquefied propane gas is not vaporized in the heat transfer tube 6, but the liquefied propane gas not vaporized in the supply side manifold 2 is completely vaporized in the heat transfer tube 6.

At this time, according to the present invention, since the jacket pipe 22 that surrounds the outside of the liquefied petroleum gas pipe 21 and allows the hot water to flow is arranged, from the outer periphery of the jacket pipe 22,
The thermal energy of the hot water that has escaped to the atmosphere heats the heat transfer tubes 6 and the heat transfer fins 8 located between the supply-side manifold 2 and the discharge-side manifold 4,
Therefore, the vaporization action of the liquefied propane gas by the heat transfer tube 6 can be promoted.

The temperature of the hot water discharged from the outlet of the jacket pipe 22 and flowing into the hot water storage tank 31 is lowered by the heat exchange with the liquefied propane gas, and therefore, for example, it is arranged at an appropriate position in the return pipe line L ₂ . The temperature detecting means 32 detects the temperature of the hot water. Based on the signal from the temperature detecting means 32, the hot water storage tank
31 is heating-controlled, and the jacket pipe 22
The water sent to is heated to a predetermined temperature.

Further, when the hot water in the hot water storage tank 31 has its water level lowered due to evaporation or the like, the level detector 33 detects the water level drop, and the signal of the level detector 33 causes the valve 34 of the water supply line L ₃ to be turned on. It controls and supplies predetermined water to the warm water storage tank 31 through the water supply line L ₃ .

In the above description, the hot water heating of the supply side manifold 2 has been described as being used in a severe cold season when the atmospheric temperature becomes lower than −8 ° C., or in the case of using in a cold district. However, for example, in the summer, the heat transfer tube 6 is used. Alternatively, when frost is formed on the heat transfer fins 8, hot water heating can be performed, whereby such frost can be automatically removed, and preliminary vaporization for switching for frost removal. The need for a vessel is avoided.

To further explain, even in the summer, by causing hot water to flow through the jacket pipe 22, the vaporization of the liquefied propane gas flowing in the liquefied petroleum gas pipe 21 is promoted, and the vaporization action of the heat transfer tubes 6 and the heat transfer fins 8 is performed. As described above, the heat energy of the hot water that has escaped from the outer periphery of the jacket pipe 22 to the atmosphere is transferred between the supply-side manifold 2 and the discharge-side manifold 4. By providing the tubes 6 and the heat transfer fins 8, it is possible to effectively achieve the removal of frost from the heat transfer tubes 6 and the heat transfer fins 8. Therefore, according to the present invention, the switching prevaporizer and the like conventionally prepared for use when the heat transfer tubes 6 and the heat transfer fins 8 are frosted are unnecessary.

Further, in the above description, the case where the air-temperature / hot-water dual-use vaporizer 1 configured according to the present invention is used in a 13A propane air gas production plant has been described. It can be suitably used for vaporizing other LPG, for example, liquefied butane.

In other words, liquefied butane used in butane air gas plant has a high boiling point, that is, it is about 15 ° C in the case of 1 kg / cm ² · G, and it was impossible to use the conventional air-temperature type forced vaporizer. The air-heated / hot-water type vaporizer 1 of the present invention can be preferably used, and vaporization of liquefied butane can be achieved extremely efficiently.

EFFECT OF THE INVENTION Air temperature provided with the air temperature / hot water type vaporizer according to the present invention
Since the LPG air gas production plant that also serves as hot water is configured as described above, (1) Air temperature type in summer, hot water type in winter, etc.
Switching operation is possible depending on climatic conditions, etc., and LPG can be suitably vaporized even in a cold region or a severe cold season.

(2) The hot water heating increases the vaporization capacity and the evaporation capacity of the air-temperature vaporization device, and the hot water heating makes it possible to remove frost on the heat transfer tubes and the like, thus eliminating the need for a preliminary vaporizer for switching.

(3) Not only can it be effectively applied to the 13A propane air gas production plant, but it can also be applied to the butane air gas production plant where conventional air-temperature forced vaporizers could not be used, and efficiently produce LPG air gas. can do.
It has various benefits such as.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of an air-temperature / hot-water type vaporizer that constitutes a main part of the present invention. FIG. 2 is a perspective view of the supply side manifold. FIG. 3 is a cross-sectional view of the supply side manifold. 1: Air-heated / hot-water type vaporizer 2: Supply side manifold 4: Discharge side manifold 6: Heat transfer tube 8: Heat transfer fin 21: Liquefied petroleum gas pipe 22: Jacket pipe 27: Annular baffle plate 30: Hot water supply source

Claims (3)

[Claims] 1. A liquefied petroleum gas, which is liquefied propane gas or liquefied butane gas, is vaporized by an air temperature / hot water vaporizer, and the vaporized liquefied petroleum gas is mixed with air to produce LPG.
A plant for producing air gas, wherein the air-temperature / hot-water type vaporizer has a supply-side manifold, a discharge-side manifold, one end connected to the supply-side manifold, and the other end connected to the discharge-side manifold. A plurality of heat transfer tubes, the supply-side manifold, a liquefied petroleum gas pipe connected to one end of each heat transfer tube, and a jacket arranged to surround the outside of the liquefied petroleum gas pipe A dual pipe structure with a pipe, liquefied petroleum gas is supplied to the liquefied petroleum gas pipe, and hot water is supplied to the jacket pipe. . 2. The air temperature / hot water combined type LPG air gas production plant according to claim 1, wherein the liquefied petroleum gas pipe is provided with an annular baffle plate. 3. The air temperature / hot water combined LPG air gas production plant according to claim 1, wherein the hot water is water mixed with an antifreeze liquid.