JP2514528Y2 - Pre-cooling device for liquefied gas supply piping - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an improvement of a precooling device for a liquefied gas supply pipe.

(Prior Art) As shown in FIG. 3, a conventional liquefied gas supply facility is usually a liquefied gas storage facility 1 including a liquefied gas storage tank and a liquefied gas pressure vessel, a liquefied gas supply pipe 2, a precooling valve 3, and a source valve 4. It is composed of a precooling gas discharge pipe 5 and a liquefied gas use facility 6 and the like. To supply only the liquefied gas directly to the liquefied gas use facility 6 through the source valve 4, the vaporized gas in the supply pipe 2 is discharged. At the same time, it is necessary to precool the supply pipe 2 to near the temperature of the liquefied gas to reduce the vaporization of the liquefied gas inside the supply pipe 2.

Therefore, when supplying the liquefied gas, first, the precooling valve 3 is opened with the use valve 4 closed, and the liquefied gas flows into the supply pipe 2 to exchange heat therewith, and the vaporized gas generated by the heat exchange While the supply pipe 2 is cooled while dispersing the gas to the outside through the discharge pipe 5, and the completion of the pre-cooling is performed from the adhesion of frost on the pre-cooled gas discharge pipe 5 without confirming that the released gas has changed from the vaporized gas to the liquefied gas. Assuming that the pre-cooling valve 3 was closed.

Further, in the conventional liquefied gas supply equipment, the supply pipe 2 must be pre-cooled by manual operation every time the liquefied gas use equipment 6 is supplied, which requires a lot of manpower and automation of the entire liquefied gas supply system. There was a difficulty that it could not be measured.

Therefore, the applicant of the present invention has separately developed an automatic control type precooling device as shown in FIG. 4 and applied for a utility model registration.

That is, in the automatic control type precooling device, the liquefied gas use request signal 9 from the liquefied gas use equipment 6 side is input to the precooling control device 8 to open the precooling control device 8 to the precooling valve 3. The signal 13a is output and the precooling valve 3 is opened. As a result, the liquefied gas flows in the supply pipe 2 and exchanges heat with the pipe 2 to cool it and sequentially vaporize it.
It is discharged to the outside through the precooling gas discharge pipe 5. Further, when the supply pipe 2 is cooled and the input temperature signal 14 from the temperature sensor 7 becomes equal to or lower than the set temperature, the pre-cooling control device 8 sends a valve closing signal 13b to the pre-cooling valve 3 and the source valve 4
A valve open signal 15 is transmitted to the liquefied gas using equipment 6 and the supply of the liquefied gas to the liquefied gas using facility 6 is started.

The automatic control type precooling device exhibits excellent practical utility in automating the entire liquefied gas supply system.

However, if the discharge length of the precooling valve is slowed when the pipe length is long or the diameter is large, the precooling efficiency is good, but the time becomes very long. Also, in order to shorten the pre-cooling time, if the release speed of the pre-cooling valve is slowed down, mist is discharged from the pre-cooling valve even though the heat exchange with the pipe is insufficient and the pipe pre-cooling is insufficient, and the consumption of liquefied gas is reduced. There was a problem that it would increase.

(Problems to be Solved by the Invention) The present invention has the above-mentioned problems in the above-mentioned automatic control type precooling device, that is, when the length and diameter of the liquefied gas supply pipe are increased, (a) the precooling time is increased. In addition, and (b), a large amount of liquefied gas is directly discharged into the atmosphere from the precooling gas discharge pipe, and it is intended to solve the two problems that the consumption of liquefied gas required for precooling increases. The present invention provides an automatic precooling device for a liquefied gas supply pipe, which can efficiently precool the supply pipe to a desired temperature in a short time depending on the gas consumption.

(Means for Solving the Problem) The present invention relates to an automatic opening-and-closing type precooling valve 3 provided at the end of a supply pipe 2 communicating with a liquefied gas storage facility 1, and a liquefied gas use facility branched from the supply pipe 2. 6, an automatic opening / closing source valve 4 for controlling the liquefied gas 11 supplied to the pre-cooling valve 6;
Detection sensor 7 of the supply pipe 2 provided near the outlet side of the
When the liquefied gas use request signal 9 is input from the liquefied gas use facility 6 side, an opening signal 13a is transmitted to the precooling valve 3 to open the precooling valve 3, and then an input temperature signal 14 from the temperature sensor 7 is output. When the temperature is equal to or lower than the set temperature, a valve closing signal is issued to the pre-cooling valve 3 to close the pre-cooling valve 3, and after a lapse of a certain time from the closing of the pre-cooling valve 3, the valve opening signal 13 to the pre-cooling valve 3 is again provided.
a is sent to open the pre-cooling valve 3, and when the input temperature signal 14 from the temperature sensor 7 is below the set temperature, a valve closing signal 13b is sent to the pre-cooling valve 3 and a valve opening signal 15 is sent to the source valve 4. The pre-cooling control device 8 for transmitting the above is the basic configuration of the invention.

(Operation) Liquefied gas use request signal 9 from liquefied gas use facility 6
Is input to the pre-cooling control device 8, the pre-cooling control device 8 outputs a valve opening signal 13a to the pre-cooling valve 3 to open the pre-cooling valve 3. As a result, the liquefied gas flows in the supply pipe 2, sequentially cools the pipe 2 from the upstream side, vaporizes it, and discharges it to the outside through the precooling gas discharge pipe 5. At this time, when the precooling gas discharge rate from the precooling valve 3 is fast, the mist runs in the pipe 2 without sufficiently precooling the downstream side of the supply pipe 2, and the input temperature signal 14 from the temperature sensor 7 is set. When the temperature becomes equal to or lower than the temperature, a valve closing signal 13b is transmitted from the control device 8 to the pre-cooling valve 3, and the pre-cooling valve 3 is kept closed for a certain period of time.

As a result, when the precooling valve 3 is closed, the spherical liquefied gas 11 'remaining in the supply pipe 2 is stagnated at that location, the flow of mist in the supply pipe 2 is stopped, and heat exchange with the pipe 2 is performed. Vaporize. That is, the downstream side of the pipe 2 is uniformly cooled while the precooling valve 3 is closed, and the temperature gradient becomes almost zero.

After a predetermined time set in advance, the control device 8 sends a valve opening signal 13a to the precooling valve 3 again to open the precooling valve 3.

As a result, the liquefied gas 11 flows in the supply pipe 2, but since the supply pipe 2 is uniformly cooled by the pre-cooling in the first stage, the supply pipe 2 is efficiently cooled to the set temperature in the second stage. To be done.

When the temperature signal 14 from the temperature sensor 7 becomes equal to or lower than the set temperature, the control device 8 sends a valve closing signal 13b to the pre-cooling valve 3 and also sends a valve opening signal 15 to the source valve 4.
The liquefied gas is supplied to the liquefied gas using facility 6.

(Embodiment) Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is an overall system diagram of a precooling device for a liquefied gas supply pipe according to the present invention, and FIG. 2 is an operation explanatory diagram of the precooling device according to the present invention.

In the figure, 1 is a liquefied gas storage facility consisting of a liquefied gas storage tank or pressure vessel for nitrogen, oxygen, argon, etc., 2 is a liquefied gas supply pipe such as a vacuum heat insulation pipe, 3 is an ultra-low temperature solenoid valve and ultra-low temperature Automatic open / close type pre-cooling valve consisting of pilot type control valve etc., 4 is an automatic open / close type main valve consisting of an ultra-low temperature solenoid valve attached to a branch pipe of the supply pipe, 5 is a vaporized gas discharge pipe, 6 is a liquefied gas using facility , 7 is a temperature sensor provided near the outlet side of the precooling valve 3, 8 is a control device including relays and programmable controllers, 9 is a liquefied gas use request signal transmitted from a liquefied gas use facility, and 10 is An automatic open / close type supply source valve, 11 is a liquefied gas, and 12 is a discharge gas from which the liquefied gas is evaporated.

When the liquefied gas 11 is not used in the liquefied gas use facility 6, the supply source valve 10 is kept in a normally open state,
The pre-cooling valve 3 and the use source valve 4 are each maintained in a closed state.

Now, when the liquefied gas usage equipment 6 requires the liquefied gas 11, a liquefied gas usage request signal 9 is sent from various sensors or push buttons (not shown) provided on the liquefied gas usage equipment 6 side.
Is transmitted, and the signal 9 is input to the control device 8.

As shown in FIG. 2, the controller 8 first determines the presence or absence of a liquefied gas use request signal 9 (step A). When the input of the signal 9 is confirmed, a valve opening signal 13a is transmitted to the pre-cooling valve 3 and the valve is opened. Opening is performed (step B). This allows
The liquefied gas 11 flows from the liquefied gas storage facility 1 into the supply pipe 2, undergoes heat exchange with the pipe 2, evaporates, and is discharged to the outside as a discharge gas 12 (step C).

On the other hand, the temperature sensor 7 provided near the outlet side of the pre-cooling valve 3
The temperature of the supply pipe 2 (or the temperature of the released gas 12) is detected (step D), and the detected temperature signal 14 is detected.
Is input to the control device 8. The detected temperature of the supply pipe 2 is a set temperature (for example, in the case of nitrogen gas, about -150 ° C).
It is judged whether or not the temperature is lower than a certain temperature (about -190 ° C) (step E), and if the detected temperature of the supply pipe 2 is lower than the set temperature, a closing signal 13b is transmitted to the automatic opening / closing precooling valve 3. Then, it is closed (step F), but at this time, the downstream side of the supply pipe 2 is not yet sufficiently cooled due to the mist. While the pre-cooling valve 3 is closed for a predetermined period of time (for example, a short time of several seconds to 20 seconds), the liquefied gas 11 remaining in the supply pipe 2 is vaporized to the downstream side of the pipe 2. Is cooled (step G).

The closing time of the precooling valve 3 is appropriately set by a timer or the like, and when the elapse of the set time is confirmed (step H), the precooling valve 3 is opened again (step I), and the liquefied gas is fed into the supply pipe 2. 11 will be supplied.

By the resupply of the liquefied gas 11, the downstream side of the supply pipe 2 is effectively cooled again (step J), and the temperature of the supply pipe 2 (or the temperature of the released gas 12) is detected by the temperature sensor 7. The detected temperature signal 14 is input to the control device 8. It is judged whether or not the detected temperature of the supply pipe 2 is below the set temperature (step K), and if the detected temperature is below the set temperature, a closing signal 13b is transmitted to the automatic opening / closing precooling valve 3. This is closed (step L), and a valve opening signal 15 indicating completion of precooling is transmitted to the automatic opening / closing type source valve 4 (step M). As a result, the source valve 4 of the liquefied gas use equipment 6 that has transmitted the liquefied gas use request signal 9 is opened, and the liquefied gas 11 is supplied to the liquefied gas use equipment 6.

In this embodiment, a direct-acting ultra-low temperature solenoid valve is used as the automatic opening / closing type pre-cooling valve 3. However, when the supply pipe 2 has a large diameter exceeding 1 ″, the direct-acting electromagnetic valve is used. An air pressure control valve using a so-called pilot solenoid valve may be used instead of the valve.

Further, in this embodiment, the pre-cooling control device 8 is a so-called centralized control type, and the control device 8 directly controls opening / closing of the pre-cooling valve 3 and each of the source valves 4, but in the vicinity of each valve 3,4. It is also possible to install a sub control device and control opening and closing of these via the sub control device in response to an operation signal from the control device 8.

(Effect of the Invention) In the present invention, since the liquefied gas is poured into the liquefied gas supply pipe in multiple times to precool the supply pipe in stages, the supply pipe is long or Even if the diameter is large, the direct discharge of the liquefied gas from the discharge pipe during the precooling is reduced, the supply pipe can be precooled in a short time, and the consumption of the liquefied gas is reduced.

Further, the supply pipe can be pre-cooled by the automatic operation, which was conventionally performed manually every time the liquefied gas is supplied to the equipment using the liquefied gas, and the number of workers can be reduced and the work efficiency can be improved.

Further, since the temperature of the supply pipe during precooling is detected by the temperature sensor, it is possible to more accurately determine the completion of precooling as compared with the case where the completion of precooling is estimated from the change in the state of vaporized gas release. I can.

As described above, according to the present invention, it is possible to automate the entire liquefied gas supply system, which has excellent practical utility.

[Brief description of drawings]

FIG. 1 is an overall system diagram of a liquefied gas supply facility provided with a precooling device according to the present invention. FIG. 2 is an operation explanatory view of the precooling device according to the present invention. 3 and 4 are overall system diagrams of conventional liquefied gas supply equipment. 1 …… Liquefied gas storage facility 2 …… Supply pipe 3 …… Automatic opening / closing precooling valve 4 …… Automatic opening / closing source valve 5 …… Precooling gas discharge pipe 6 …… Liquefied gas using equipment 7 …… Temperature sensor 8… … Precooling control device 9 …… Liquefied gas use request signal 10 …… Source valve 11 …… Liquefied gas 12 …… Outgassing gas 13a …… Precooling valve opening signal 13b …… Precooling valve closing signal 14 …… Input from temperature sensor Temperature signal 15 ... Source valve open signal

Claims (1)

(57) [Scope of utility model registration request] 1. An automatic opening / closing precooling valve (3) provided at the end of a supply pipe (2) communicating with a liquefied gas storage facility (1);
An automatic opening-closing type main valve (4) for controlling the liquefied gas (11) branched from the supply pipe (2) and supplied to the liquefied gas using equipment (6); in the vicinity of the outlet side of the precooling valve (3) The temperature detection sensor (7) of the provided supply pipe (2) and the liquefied gas use request signal (9) from the liquefied gas use facility (6) side are input to the pre-cooling valve (3) to open the valve (13).
a) is sent to open the precooling valve (3), and when the input temperature signal (14) from the temperature sensor (7) is below the set temperature, a valve closing signal is issued to the precooling valve (3). The pre-cooling valve (3) is closed, and after a certain time has passed since the closing of the pre-cooling valve (3), the pre-cooling valve (3) is again sent with a valve opening signal (13a) to open the pre-cooling valve (3). When the input temperature signal (14) from the temperature sensor (7) is below the set temperature, the valve closing signal (13b) is sent to the pre-cooling valve (3) and the valve opening signal (15) is sent to the source valve (4). A precooling device for a liquefied gas supply pipe, which comprises a precooling control device (8) for transmitting.