JP5270130B2 - Odorant addition device and operation method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an odorant adding device suitable for fuel gas supply equipment that is often and repeatedly started and stopped. <P>SOLUTION: The passage from piping L5 to piping L3 is configured to decline in this order so that, with an effect of a narrowing member 10, an odorant gas does not stay in the piping when operation is stopped. The narrowing member 10 to minimize the inner volume of the pipe is fitted in the piping L3. The upper part and the lower part of the narrowing member 10 are provided with an upper groove 11a and a lower groove 11b, respectively; an odorant liquid flows in the upper groove 11a and the lower groove 11b; and an odorant gas generated when operation is stopped remains in the upper groove 11a and is further guided upward along the slope of the piping from L3 to L5 and finally returned to an odorant tank 2 upon operating a circulation system. The inner diameter d of a nozzle 6 is set to a diameter that the odorant liquid does not remain in the nozzle because of surface tension when the operation is terminated but completely drops into a conduit. The passage from the piping L3 to piping L4 is configured to decline and to be as short as possible to prevent retention of the odorant in the piping. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to an odorant addition device for odorizing fuel gas, such as city gas, and an operation method thereof, and particularly to an odorant addition device suitable for a fuel gas supply facility that is frequently started and stopped, and It relates to the driving method.

For city gas, LPG, etc., odorant is generally added and supplied for easy detection at the time of leakage, but the amount of odorant added to the amount of gas sent is very small. It is not easy to control the addition of the odorant to a certain amount. If the concentration of the odorant is too low, there is a problem that the detection at the time of leakage is hindered. On the other hand, if the odorant concentration is too high, it causes a complaint from a customer or the like.
For this reason, various techniques relating to the stable addition of odorants have been proposed. For example, when injecting the odorant delivered from the odorant tank with the metering pump into the supply conduit via the odorant supply pipe, the valve opening degree of the flow control valve provided in the middle of the path is set. A technique has been proposed in which a desired injection amount is maintained by controlling the pressure difference between the primary side and the secondary side to be constant (Patent Document 1). According to this technique, the odorant can be stably injected, but there is a problem that the apparatus configuration is complicated and the cost cannot be avoided.

Further, a technique for controlling the injection amount by devising the structure of the odorant injection nozzle has been proposed (for example, Patent Document 2). FIG. 8 shows the odorant adding device 100. This is because an odorant injection chamber 104 is provided at a position surrounding the upper end of the injection nozzle 105, and a plurality of small holes 105a are formed in the nozzle side wall in the odorant injection chamber in a plurality of stages in the vertical direction. The odorant introduced into the injection chamber 104 is overflowed from the small hole 105 a and injected into the supply gas conduit 106 through the odorant injection nozzle 105.
According to the odorant addition device 100, the odorant in the odorant tank 101 is temporarily stored in the odorant injection chamber 104 via the odorant supply pipe 107 by the operation of the metering pump 102. When the liquid level in the injection chamber rises and reaches the position of the lowest hole, it overflows into the odorant injection nozzle 105. When the odorant introduction amount is a flow rate that cannot be treated only from the first-stage small holes, the liquid level in the room rises and sequentially overflows from the second-stage and third-stage small holes. This technique has a feature that enables stable injection of an odorant with such a simple configuration.
JP 2004-174462 A JP 2004-75726 A

  However, in the odorant addition apparatus 100, the liquid staying in the odorant injection chamber and the nozzle portion evaporates when the operation is stopped and diffuses into the supply gas conduit, so that the odorant concentration of the gas in the pipe is abnormal. There is a problem that the gas of excessive odor is temporarily supplied at the start of operation. For this reason, it is difficult to apply the above technique to a gas supply facility that is frequently started and stopped.

This invention is for solving such a subject, and provides the odorant addition apparatus applicable also to the gas supply equipment in which starting and a stop are repeated repeatedly. The gist of the present invention is as follows. That is,
(1) An odorant addition device provided in a supply gas conduit path, which connects a storage tank for storing the odorant, a storage tank and a supply gas conduit, An odorant injection system for introducing the odorant into the supply gas conduit, an odorant pump provided in the odorant injection system via a pipe, an injection valve, an injection nozzle, and an odorant pump Branching from a pipe connecting the injection valve to the injection valve, an odorant reflux system for returning the staying odorant in the odorant injection system to the liquid storage tank, and a pipe in the odorant reflux system via the pipe And an odorant addition device characterized in that the odorant addition device is provided.

(2) The above invention is characterized in that the pipe connecting the injection valve and the reflux valve is provided with gas accumulation preventing means for preventing the odorant gas from staying at the time of operation stop.
(3) In each of the above inventions, the gas accumulation preventing means is an up-gradient pipe from the injection valve to the reflux valve.
(4) In each of the above inventions, the gas accumulation preventing means is a constricting member fitted into a pipe connecting the injection valve and the reflux valve.
(5) In the above invention, the narrowing member is a round bar provided with a plurality of grooves.
(6) In each of the above inventions, the gas accumulation preventing means is characterized in that a pipe connecting the injection valve and the reflux valve is configured to have a minimum length necessary for maintenance of the injection valve or the reflux valve.
(7) In each of the above inventions, the pipe connecting the injection valve and the injection nozzle is provided with a liquid pool preventing means when the operation is stopped.
(8) The above invention is characterized in that the liquid pool preventing means is a downward slope pipe from the injection valve to the injection nozzle.
(9) In each of the above inventions, the liquid pool preventing means is characterized in that the pipe connecting the injection valve and the injection nozzle is configured to have a pipe length in which the odorant liquid does not stay in the pipe at the end of operation. To do.
(10) In each of the above inventions, the liquid pool preventing means is configured such that the injection nozzle has an inner diameter at which the odorant liquid does not stay in the nozzle at the end of the operation.

(11) In each odorant addition device described above, at the time of start-up, prior to the odorant addition operation, the odorant is circulated from the odorant injection system to the odorant reflux system to inject the odorant. An operation method of an odorant addition device, characterized in that the odorant gas staying in the system piping is degassed.

According to the present invention, there is an effect that it is possible to add a certain concentration of odorant even in the case of a gas supply facility that is frequently started and stopped.
Moreover, according to the invention in which the gas accumulation prevention mechanism is provided in the pipe connecting the injection valve and the reflux valve, the odorant gas can be prevented from staying in the pipe during the operation stop time zone. As a result, the pump can be smoothly pumped at the time of startup, and the odorant can be stably injected.
In addition, according to the invention in which a liquid pool preventing mechanism is provided in the pipe connecting the injection valve and the injection nozzle, “drip” from the nozzle portion into the gas conduit in the odorant injection stop time zone, the nozzle portion “puddle” Therefore, the concentration of the odorant of the supply gas staying in the pipe can be prevented from becoming abnormally high.

Hereinafter, embodiments of the present invention will be described in more detail with reference to FIGS. Needless to say, the scope of the present invention is described in the claims and is not limited to the following embodiments.
FIG. 1 is a diagram illustrating an overall configuration of an odorant adding apparatus 1 according to the present embodiment. The odorant addition device 1 connects the odorant tank 2, the odorant tank 2 and the gas conduit 5, and injects the odorant to guide the odorant in the odorant tank 2 to the gas conduit 5. The system 3 and the odorant recirculation system 4 for branching from the point A in the route of the odorant injection system 3 and returning the odorant in the injection system piping to the odorant tank 2 are configured. .
The odorant injection system 3 is disposed at the odorant injection pipes L1 to L4, the odorant pump 7 interposed between L1 and L2, the injection valve V1 interposed between L3 and L4, and the tip of L4. And an injection nozzle 6 mounted inside the gas conduit 5 as a main component.
The odorant recirculation system 4 includes, as main components, recirculation pipes L5 and L6 and a recirculation valve V2 interposed between L5 and L6.

Between the pipes L5 and L3, it is configured to have a downward slope in this order, and in combination with the effect of the narrowing member 10 described later, the odorant gas is configured not to stay in the pipe when the operation is stopped. ing. In addition, although the piping L5 and L3 are divided | segmented and shown for convenience, they are actually formed with one straight pipe, and the piping L2 joins this in the A point.
Next, FIG. 2 is a diagram showing the in-pipe configuration of the odorant injection pipe L3. A narrowing member 10 for minimizing the volume in the pipe is fitted in the pipe L3. However, both ends (the point A and the vicinity of the injection valve V1) of the pipe L3 are not narrowed, and are configured so as not to hinder the inflow of the odorant from the pipe L2 or the outflow to the injection valve V1. ing. The constricting member 10 is configured by a round bar having an outer diameter slightly smaller than the inner diameters of the pipes L5 and L3. An upper groove 11a and a lower groove 11b are provided at the upper and lower portions of the constriction member 10, respectively. The odorant liquid flows through the upper groove 11a and the lower groove 11b, and the odorant gas generated when the operation is stopped is accumulated in the upper groove 11a and further guided upward along the inclination of the pipe L3 → L5. Further, it is configured to be returned to the odorant tank 2 during the reflux system operation (described later). The piping L5 is also configured in the same way.

  Next, FIG. 3 is a diagram showing a detailed configuration in the vicinity of the injection nozzle 6. The nozzle tip 6a is fixed in the gas conduit 5 by a flange 6b. The inner diameter d of the nozzle 6 is set to a diameter at which the odorant liquid does not stay in the nozzle due to surface tension at the end of the operation, but drops completely into the conduit. Further, the pipes L3 → L4 have a downward slope and are configured to be as short as possible so as not to stay in the pipe.

The odorant addition apparatus 1 is configured as described above. Next, an operation control method at the start and stop of the operation of the odorant addition apparatus 1 will be described with reference to FIGS. 4 to 7. This control is performed by a control unit (not shown) that controls each actuator.
Referring to FIG. 4, in the initial state, both the injection system 3 and the reflux system 4 are stopped, that is, the odorant pump 7 → stop, V1 → close, and V2 → open (S101). When an operation start command is sent from the control unit in this state (S102), first, the reflux system 4 is in an operating state (odorant pump 7 → operation, V1 → closed, V2 → open) (S103). As a result, as shown in FIG. 5, the odorant circulates in the reflux system 4, and the residual gas in the pipe is purged. After the elapse of a predetermined time necessary for the gas purge (YES in S104), the reflux system 4 is stopped and the pressure raising operation of the injection system is started. In this case, the odor pump 7 → operation, V1 → close, and V2 → close (S105). After the pressure is increased to the pressure required for odorant injection (YES in S106), the injection system 3 is brought into an operable state. In this case, the odorant pump 7 → operation, V1 → open, and V2 → close (S107). As a result, as shown in FIG. 6, the odorant flows through the injection system 3, and injection from the injection nozzle 6 into the supply gas conduit 5 is started (S108).

Next, a control method at the time of operation stop will be described with reference to FIG. When the operation is continued, the reflux system 4 is stopped, the injection system 3 is in operation (see FIG. 6), the odorant pump 7 → operation, V1 → open, and V2 → close (S201). When an operation stop command is sent from the control unit in this state (S202), both the injection system 3 and the reflux system 4 are stopped. That is, the odorant pump 7 is stopped, V1 is closed, and V2 is opened (S203).
In this embodiment, a round bar having a groove as a constricting member is inserted into the injection pipe. However, the present invention is not limited to this, and the flow of the odorant gas and liquid is ensured in the pipe, and the internal volume It is also possible to use a member having a minimum cross section, for example, a rod having a polygonal cross section inscribed in the pipe.

  The present invention is not limited to fuel gas, and can be widely used for adding an odorant that requires an odor when supplying gas.

It is a figure which shows the structure of the odorant addition apparatus 1 which concerns on one Embodiment of this invention. It is a figure which shows the internal structure of the odorant injection | pouring piping L3. It is a figure which shows the detailed structure of the injection | pouring nozzle 6. FIG. It is a figure which shows the control flow at the time of the driving | operation start of the odorant addition apparatus. It is a figure which shows the flow path of the odorant at the time of a reflux system operation | movement. It is a figure which shows the flow path of an odorant at the time of injection | pouring system operation | movement. It is a figure which shows the control flow at the time of the driving | operation stop of the odorant addition apparatus. It is a figure which shows the structure of the conventional odorant addition apparatus 100. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... odorant addition apparatus 2 ... odorant tank 3 ... odorant injection system 4 ... odorant reflux system 5 ... gas conduit 6 ...・ Injection nozzle 7... Odorant pump 10... Constriction members L1 to L4... Odorant injection pipes L5 and L6. Reflux valve

Claims (10)

An odorant addition device provided in a supply gas conduit path,
A liquid storage tank for storing odorants;
An odorant injection system for connecting the liquid storage tank and the supply gas conduit, and for introducing the odorant in the storage tank into the supply gas conduit;
An odorant pump provided in the odorant injection system via a pipe, an injection valve, an injection nozzle,
An odorant recirculation system for branching from the pipe connecting the odorant pump and the injection valve and returning the scented odorant in the odorant injection system to the storage tank;
A reflux valve provided in the odorant reflux system via a pipe;
In the pipe connecting the injection valve and the reflux valve , a gas accumulation preventing means for preventing the retention of the odorant gas when the operation is stopped ,
An odorant addition device comprising: The odorant addition device according to claim 1 , wherein the gas accumulation preventing means is an ascending pipe from the injection valve to the reflux valve. The odorant addition device according to claim 1 or 2 , wherein the gas accumulation preventing means is a constricting member fitted into a pipe connecting the injection valve and the reflux valve. The odorant adding device according to claim 3 , wherein the constricting member is a round bar provided with a plurality of grooves. The gas reservoir prevention means, said injection valve and a pipe connecting the said recirculation valve, 1 to claim, wherein the injection valve or at configured the shortest length required for maintenance of the recirculation valve 4. The odorant addition apparatus according to any one of 4 above. The odorant addition device according to any one of claims 1 to 5, wherein a pipe connecting the injection valve and the injection nozzle is provided with a liquid pool preventing means when operation is stopped. The odorant adding device according to claim 6 , wherein the liquid pool preventing means is a downward slope pipe from the injection valve toward the injection nozzle. The liquid reservoir prevention means, said pipe connecting the injection valve and said injection nozzle, odorant liquid at the end of the operation is characterized in that configured in pipe length without remaining in the pipe of claim 6 or The odorant addition device according to 7. 9. The odor according to any one of claims 6 to 8, wherein the liquid pool preventing means is configured to have an inner diameter at which the odorant liquid does not stay in the nozzle at the end of operation of the injection nozzle. Agent addition equipment. In the odorant addition apparatus in any one of Claims 1 thru | or 9 ,
At startup, prior to the odorant addition operation, the odorant gas is circulated from the odorant injection system to the odorant recirculation system, and the odorant gas remaining in the odorant injection system piping A method for operating an odorant addition device, characterized in that a degassing operation is performed.

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