JP2013245741A - Hydrogen containing gas supply system for use in utility tunnel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydrogen containing gas supply system for use in a utility tunnel which can safely supply a hydrogen containing gas to each fuel cell facility without applying explosion-proof specifications to electrical facilities in the utility tunnel and without providing a partition wall over the entire length of a gas pipe laid in the utility tunnel.SOLUTION: A gas pipe G laid in a utility tunnel is formed in a double pipe structure which includes an inner pipe G1 for supplying a hydrogen containing gas and an outer pipe G2 for covering the inner pipe G1 in which two or more pressure detection means are arranged which detect pressures in the inner pipe G1, a hydrogen concentration detection means is arranged which detects a hydrogen gas concentration between the inner pipe G1 and outer pipe G2, and an alarm transmission means K is arranged which transmits a predetermined alarm. The alarm transmission means K transmits an alarm when a pressure value detected by a pressure detection means drops by a predetermined amount or more in comparison with a pressure value detected by the other pressure detection means on the upstream side or when the hydrogen concentration detection means detects a hydrogen concentration larger than a predetermined concentration.

Description

  The present invention relates to a hydrogen-containing gas supply system, and more particularly, to a hydrogen-containing gas supply system in a joint groove that supplies a hydrogen-containing gas to a fuel cell facility using a gas pipe laid in the joint groove. It is.

  In recent years, fuel cell-type power generation and hot water supply systems that generate electricity and heat by taking out hydrogen from city gas and LP gas and reacting with oxygen in the air in detached houses, office buildings, public facilities, etc. Hereinafter, fuel cell facilities including cases where there is no hot water supply function only for power generation function) have become widespread. For this reason, an attempt has been made to supply hydrogen gas directly to each fuel cell facility such as a detached house, instead of extracting hydrogen from city gas or LP gas.

However, flammable gases such as hydrogen gas, city gas, and LP gas are very flammable and may explode, so supply them to each fuel cell facility using piping laid in a public common groove In some cases, it is subject to some legal restrictions on safety, such as the “Special Measures Act on Maintenance of Common Grooves”.
Here, the common gutter refers to multiple public utilities (infrastructure) such as power / electric cable, water supply pipe, sewer pipe, gas pipe, district air conditioning heating pipe, vacuum dust collection pipe, cable TV wiring, etc. This refers to public facilities installed under the road, etc. related to the shared use of a plurality of public utilities (see Figure 6).

  For example, in order to prevent explosion when flammable gas leaks outside the pipe, the electrical facility in the common groove must be explosion-proof so that flammable gas leaked due to electrical facility switches or static sparks is not ignited. There is a provision that must be done. If all electrical facilities in the common groove are explosion-proof, the cost will be enormous. In general, by enclosing the flammable gas piping with a partition wall, it is isolated from other facilities in the common groove, and the gas leak sensor Are installed at predetermined intervals in the partition wall (see FIG. 6). However, even in that case, it is expensive to provide a partition wall over the entire length of the common groove, and for maintenance, etc., it is necessary to secure a work space with a radius of about 600 mm around the gas pipe and install the partition wall. Yes, if additional flammable gas supply piping is installed in the existing common groove, there is not enough space, and the electric facilities are not made explosion-proof, and flammable gas is supplied using the existing common groove. There is a problem that can not be.

  Patent Document 1 discloses a technique for solving the problem that even if a doping gas pipe used in semiconductor manufacturing is corroded by doping gas and a pinhole is generated and gas leakage occurs, detection is difficult. Whether the gas pipe between the high-pressure gas supply source and the pressure regulator for pressure reduction is a double pipe, high-pressure gas flows through the inner pipe, inert gas flows through the outer pipe, and high-pressure gas leaks into the inert gas. An apparatus for preventing a gas outflow phenomenon of a pressure regulator that detects the above is disclosed.

  However, the invention of the pressure regulator gas outflow phenomenon preventing device described in Patent Document 1 is about the high-pressure and extremely toxic doping gas used in semiconductor manufacturing between the high-pressure gas supply source and the pressure regulator. It is an invention applied to piping, and can be applied when supplying hydrogen gas (hydrogen-containing gas) to each fuel cell facility such as a detached house using piping laid in a common groove as in the present invention. It was not a thing.

JP-A-4-305137

  Therefore, the present invention solves the above-mentioned problems of the prior art, safely without making the electrical facility in the common groove an explosion-proof specification or providing a partition over the entire length of the gas pipe laid in the common groove. An object of the present invention is to provide a hydrogen-containing gas supply system in a common groove that can supply a hydrogen-containing gas to each fuel cell facility.

  In order to solve the above-mentioned problems, the invention described in claim 1 is a hydrogen-containing gas supply system in a joint groove that supplies a hydrogen-containing gas to a fuel cell facility using a gas pipe laid in the joint groove. The gas pipe has a double pipe structure including an inner pipe that supplies a hydrogen-containing gas and an outer pipe that loosely fits and covers the inner pipe, and detects the pressure in the inner pipe. A plurality of pressure detection means, a hydrogen concentration detection means for detecting the concentration of hydrogen gas between the inner pipe and the outer pipe, and an alarm transmission means for transmitting a predetermined alarm, the alarm transmission means, Compared with the pressure value detected by any one pressure detection means among the plurality of pressure detection means, when the pressure value detected by other pressure detection means installed on the downstream side thereof is lower than a predetermined amount, The hydrogen concentration detecting means detects a hydrogen concentration exceeding a certain concentration. If, in the case of either, or characterized by the alert when the case for the both.

  According to a second aspect of the present invention, in the hydrogen-containing gas supply system in the common groove according to the first aspect, the system includes a gas stop unit that stops the supply of the hydrogen-containing gas in response to the alarm.

  According to a third aspect of the present invention, in the hydrogen-containing gas supply system in the joint groove according to the first or second aspect, the inner pipe is made of a polyethylene pipe, and the outer pipe is made of a polyvinyl chloride pipe. It is characterized by.

  According to a fourth aspect of the present invention, in the hydrogen-containing gas supply system in the joint groove according to any one of the first to third aspects, the bent portion of the gas pipe has a joint body, and the inner pipe is provided in the joint main body. The straight pipe is assembled in a state where it is fused via an elbow pipe, and is connected to the outside by a box joint in which a straight pipe of the outer pipe projects.

  The present invention is as described above, and according to the first aspect of the present invention, the hydrogen containing gas in the common groove is supplied to the fuel cell facility using the gas pipe laid in the common groove. In the gas supply system, the gas pipe has a double pipe structure including an inner pipe that supplies a hydrogen-containing gas and an outer pipe that loosely fits and covers the inner pipe. A plurality of pressure detection means for detecting the pressure of hydrogen, a hydrogen concentration detection means for detecting the concentration of hydrogen gas between the inner tube and the outer tube, and an alarm transmission means for transmitting a predetermined alarm, The alarm transmission means has a predetermined amount of pressure value detected by another pressure detection means installed downstream from the pressure value detected by any one of the plurality of pressure detection means. If the hydrogen concentration is lowered, the hydrogen concentration detecting means When the concentration is detected, an alarm is issued when either or both of the above cases are met, so the electrical facilities in the common groove will be explosion-proof or the gas pipes installed in the common groove A hydrogen-containing gas can be safely supplied to each fuel cell facility using a gas pipe laid in the common groove without providing a partition wall over the entire length. For this reason, when laying a gas pipe for supplying hydrogen, a significant cost reduction can be achieved. In the unlikely event that hydrogen-containing gas leaks from the inner pipe, the alarm can be immediately detected by an alarm from the alarm transmission means, and the outer pipe covers the inner pipe. Since diffusion can be temporarily blocked, there is no danger of explosion or fire, and it is safe. In addition, because the pressure detection means and the hydrogen concentration detection means are equipped with double gas leak detection means, even if one of the detection means fails, the gas leak of hydrogen-containing gas is reliably detected. This system is safer and it is possible to confirm and verify the malfunction of each detection means, so that the system can be reliably operated.

  According to the invention described in claim 2, in the hydrogen-containing gas supply system in the joint groove according to claim 1, since it has a gas stop means for stopping the supply of the hydrogen-containing gas in response to the alarm, the function and effect are provided. In addition, when hydrogen gas leaks, the supply of the hydrogen-containing gas can be stopped immediately and the system can be operated more safely.

  According to a third aspect of the present invention, in the hydrogen-containing gas supply system in the joint groove according to the first or second aspect, the inner pipe is made of a polyethylene pipe, and the outer pipe is made of a polyvinyl chloride pipe. Therefore, in addition to the above-described effects, the use of a polyethylene pipe that is flexible and can be electrically welded to the inner pipe through which the hydrogen-containing gas circulates may cause gas to leak from the joint of the gas pipe due to an earthquake or the like. There are few, work efficiency is good, and it can construct at low cost. In addition, the outer pipe that covers the inner pipe is made of a polyvinyl chloride pipe that is less distorted by creep, excellent in chemical resistance and durability, flame retardant, and has a self-extinguishing function. There is little deterioration, and there is little influence of hydrogen sulfide in acidic soil and sewage, so that it is possible to cover the drawbacks of polyethylene pipes that are vulnerable to ultraviolet rays, and to reduce the risk of fire spread in the event of a fire. Moreover, it can be constructed inexpensively as a whole.

  According to a fourth aspect of the present invention, in the hydrogen-containing gas supply system in a joint groove according to any one of the first to third aspects, the bent portion of the gas pipe has a joint body, and the inside Since the straight pipe of the pipe is assembled in a state of being fused through the elbow pipe, and connected to the outside by a box joint in which the straight pipe of the outer pipe is projected, the gas pipe is connected to the two Even with the heavy pipe structure, it is possible to efficiently perform the connecting work of the bent portion, and it is possible to increase the work efficiency and to perform the work at a low cost.

It is a vertical sectional view showing typically the gas pipe laid in the common groove according to the embodiment of the present invention. The state which cut | disconnected the straight part of the gas pipe same as the above by the perpendicular plane orthogonal to piping, (a) is sectional drawing which shows the state cut | disconnected by the vertical plane orthogonal to piping, (b) is horizontal direction of piping. It is an elevation view which shows the state seen in. It is sectional drawing which shows the box joint of a gas pipe same as the above by the vertical cut surface along the centerline of piping. It is an elevation view which shows the detection sensor attachment part of a gas pipe same as the above. It is a circuit diagram which shows the hydrogen concentration detection means which concerns on embodiment of this invention. It is a vertical sectional view which shows typically the gas pipe laid in the conventional common groove.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  A hydrogen-containing gas supply system in a common groove according to an embodiment of the present invention includes a double-pipe structure gas pipe G laid in the common groove, a pressure sensor S1 as pressure detection means, and a hydrogen concentration detection means. The hydrogen gas sensor S2 and the measurement data of these sensors S1, S2 are recorded, the alarm transmission means K for transmitting an alarm described later based on the measurement data, and the alarm of the alarm transmission means K are received. The gas stop means T is configured to stop the supply of hydrogen gas, and has a function of supplying hydrogen gas to each fuel cell facility such as a detached house or an office building using a gas pipe G.

(Gas pipe)
As shown in FIGS. 1 and 2, the gas pipe G includes an inner pipe G1 made of a polyethylene pipe having a nominal diameter of 25 for allowing hydrogen gas to circulate, and a VU hard having a nominal diameter of 75 that loosely fits and covers the inner pipe G1. It has a double tube structure composed of an outer tube G2 made of a polyvinyl chloride tube, and has a function as a route for supplying hydrogen gas to each fuel cell facility by being laid in the aforementioned common groove.

Since the inner pipe G1 has a function as a supply pipe for hydrogen gas, it is desired that there is no risk of gas leakage. Since the inner pipe G1 according to the present embodiment is made of a polyethylene pipe excellent in flexibility, it has a feature that it is more resistant to earthquakes than other steel pipes and resin pipes. And because it is excellent in flexibility, it can be transported in a state where a straight pipe is wound in a reel shape, and can be installed while being straightened at the installation site, so long installation without connection is possible In this respect, it can be said that it is excellent in earthquake resistance. In addition to the fact that polyethylene pipes can be used for long construction without connection, they can be easily joined by electrofusion (EF) with a power source, so they have high reliability in preventing gas leakage. The workability of the connection work between each other is excellent, and the material cost is also low, so the economy is very good.
The polyethylene pipe can be heat-sealed from the outside without preliminarily embedding a heating wire in a joint or the like.

  The outer tube G2 covers the inner tube G1, and has a function of preventing hydrogen gas from temporarily diffusing into other spaces of the common groove if hydrogen gas leaks from the inner tube G1. . The outer tube G2 according to the present embodiment is made of a polyvinyl chloride tube that is less distorted by creep, excellent in chemical resistance and durability, flame retardant, and has a self-extinguishing function. In addition to reducing the effects of hydrogen sulfide in acidic soil and sewage, the risk of fire spread in the event of a fire can be reduced. In addition, as the function of the outer tube G2, it is sufficient to temporarily prevent the leaked hydrogen gas from diffusing, so that strict airtightness is not required, and an adhesive is also used for connecting polyethylene tubes using a joint. Since it can connect only by apply | coating, workability is favorable and it can construct cheaply as a whole.

In addition, the inner tube G1 can be covered with the outer tube G2 which is excellent in UV resistance among the resin materials, so that the defects of the inner tube G1 made of polyethylene tube which is weak against UV rays can be covered. It can be installed at a place where the ultraviolet rays from sunlight are irradiated or outside the common groove, and is versatile and is preferable as a gas pipe.
However, under direct sunlight, it is preferable to coat the outer circumference of the outer tube G2 with a weather resistant tape, a weather resistant paint or the like.

  As for the piping operation of the gas pipe G, for a general straight line portion, the inner pipe G1 of the polyethylene pipe wound in a reel shape is extended, and the outer pipe G2 is passed through the outer pipe G2 of a straight straight polyvinyl chloride pipe. The straight pipes are bonded to each other through a joint and supported by a support groove on a joint groove or the like with a support fitting. For the connecting portion of the straight inner pipe G1, the straight pipes of the polyethylene pipes are electrofused together, and then the joint part is sandwiched from outside using a polyvinyl chloride halved joint pipe and bonded.

(Box joint)
The bent portion of the gas pipe G is connected by a special box joint G3 manufactured at the factory. As shown in FIG. 3, this box joint G3 is based on a joint body G30 made of approximately 200 mm square polyvinyl chloride, and this joint body G30 has the same diameter as the straight pipe portion of the outer pipe G2. Straight pipes G31 and G32 project outward from the two faces of the cube by about 100 mm. In addition, the joint body G30 was divided into two parts by connecting two straight pipes G33 and G34 of polyethylene exceeding 200 mm by means of electrofusion (black solid portion in the figure) with polyethylene elbow pipes G35. The joint receiving plate G36 is sandwiched and assembled. For this reason, even in the bent portion of the gas pipe G, the straight pipe portion of the inner pipe G1 and the straight pipes G33 and G34 protruding from the box joint G3 are fused, and the straight pipe portion of the outer pipe G2 and the protrusion of the box joint G3 are fused. Since the straight pipes G31 and G32 can be connected by simply bonding them, the bent part of the double pipe can be easily constructed in a short time, and the bent part should be made in a highly reliable factory compared to on-site production. Therefore, pipe connection with higher safety is possible.

  Further, as shown in FIG. 3, a spare pipe G37 made of a straight pipe having the same diameter as that of the straight pipe G31 is projected from the joint body G30 to the outside of the box joint G3. In the event of an abnormal situation such as gas leakage, the joint between the straight pipes G33 and G34 and the elbow pipe G35 can be visually inspected from the outside. Note that the opening of the spare pipe G37 is normally closed with a cap G38.

In the present embodiment, it is only necessary that the outer tube G2 covers the inner tube G1 to temporarily prevent hydrogen gas from leaking, so that the inner tube G1 bends due to flexibility and the inner peripheral surface of the outer tube G2. Since there may be no contact between the inner tube G1 and the outer tube G2, a spacer or the like is not particularly installed, but a spacer or the like may be installed.
However, as will be described later, the hydrogen gas sensor S2 measures the hydrogen concentration in the air between the inner tube G1 and the outer tube G2, and there is a problem if the diffusion of hydrogen gas is hindered from the gas leakage position. Spacers that do not have pores and impede gas flow cannot be used.

(Pressure sensor and hydrogen gas sensor)
In the pressure sensor S1 and the hydrogen gas sensor S2, a plurality of sensors are attached in order from the cylinder side of the hydrogen gas at a predetermined interval in the straight pipe portion of the inner pipe G1. As shown in FIG. 4, a T75 × 40 cheese tube S10 is attached between the straight straight tubes of the outer tube G2, and a socket S12 made of polyvinyl chloride and a cap S13 thereof are connected to the cheese tube S10 via a short tube S11 of the VU40. The pressure sensor S1 and the hydrogen gas sensor S2 are mounted inside the socket S12 and the like.
The predetermined interval may be appropriately determined in consideration of the pressure loss obtained by the test of the gas pipe G, the location of the bent portion of the pipe, the supply amount of hydrogen gas, and the like.

  The pressure sensor S1 according to the present embodiment is a general pressure sensor, and a sensor portion for detecting pressure is formed so as to communicate with the inside of the inner tube G1, and the pressure of hydrogen gas in the inner tube G1 is determined. It is configured to measure, and is configured to output a measurement result to a data logger (not shown) by wire or wirelessly every set predetermined control time (for example, 1 second).

  The hydrogen gas sensor S2 according to the present embodiment is a hydrogen gas sensor having the circuit configuration shown in FIG. 5 and having a gas sensitive element as a tin oxide (Sn02) semiconductor, and is attached to the socket S12 portion of the cheese tube S10. The electrical conductivity of the sensor increases as the hydrogen concentration in the air outside the inner tube G1 communicating with the socket S12 increases in the outer tube G2. The conductivity of the gas sensitive element is corrected to a value corresponding to the hydrogen concentration, and the result is output to a data logger (not shown) by wire or wirelessly at a set predetermined control time (for example, 1 second). Has been.

  Further, this data logger is connected to a personal computer PC of an alarm transmission means described later by wire or wirelessly, and data aggregated in a personal computer (alarm transmission means) described later for every predetermined data (for example, every 1000 data). Configured to send automatically.

Next, alarm transmission means K (not shown) according to the present embodiment will be described.
The alarm transmission means K is installed in a predetermined management center or the like, and is composed of a general personal computer in which predetermined software is installed. This personal computer is a plurality of data sent from the above-mentioned data logger by executing predetermined software. A plurality of pressure values in the inner pipe G1 measured by the pressure sensor S1 are compared, and the pressure value detected by the pressure sensor S1 on the downstream side of the hydrogen gas supply takes into account the sensor installation interval, normal pressure loss, etc. When it falls below the predetermined amount, it is determined as an abnormal value and a predetermined alarm is transmitted.
Further, the personal computer as the alarm transmission means also has a predetermined value when any of the plurality of hydrogen gas sensors S2 sent from the data logger senses hydrogen having a certain concentration or more in the air between the inner pipe G1 and the outer pipe G2. The alarm is sent.

  In addition, the predetermined alarm may be sent by sending an e-mail, etc. to a designated responsible person / person in charge, reporting an abnormality, turning a patrol lamp installed in a management center, etc., or sounding a siren, etc. It is done.

Next, the gas stop means T (not shown) which concerns on this Embodiment is demonstrated.
The gas stop means T includes a receiving means T1 for receiving the alarm and an electromagnetic valve T2 capable of closing the inside of the inner pipe G1, and receives the alarm or transmits the alarm from wired / wireless. In response to an instruction from the alarm transmission means, the inner pipe G1 is instantaneously closed to stop the hydrogen gas.

  As described above, hydrogen gas has been described as an example of the gas supplied by the hydrogen-containing gas supply system according to the present embodiment, but other flammability containing hydrogen such as LP gas, natural gas, city gas, etc. The present invention can also be applied to gas. The alarm transmission means described above is not limited to a personal computer, and may be a server or a large computer (electronic computer) that can provide the same function as the above-described software, such as a pressure detection means or a hydrogen concentration detection means. Alternatively, other known pressure sensors or hydrogen gas sensors may be used. It is needless to say that other means are not limited to the illustrated embodiment and can be appropriately changed within the scope of the claims.

G Gas pipe G1 Inner pipe G2 Outer pipe G3 Box joint S1 Pressure sensor (pressure detection means)
S2 Hydrogen gas sensor (hydrogen concentration detection means)
K PC (alarm transmission means)
T Gas stop means

Claims (4)

A hydrogen-containing gas supply system in a joint groove that supplies a hydrogen-containing gas to a fuel cell facility using a gas pipe laid in the joint groove,
The gas pipe has a double pipe structure comprising an inner pipe for supplying a hydrogen-containing gas and an outer pipe for loosely fitting and covering the inner pipe.
A plurality of pressure detecting means for detecting the pressure in the inner pipe, a hydrogen concentration detecting means for detecting the concentration of hydrogen gas between the inner pipe and the outer pipe, and an alarm sending means for sending a predetermined alarm. Prepared,
The alarm transmission means is configured to detect a pressure value detected by another pressure detection means installed downstream from a pressure value detected by any one of the plurality of pressure detection means. A joint groove characterized by issuing a warning when falling below a fixed amount, when the hydrogen concentration detection means detects a hydrogen concentration exceeding a certain concentration, or in both cases Inside hydrogen-containing gas supply system.   The hydrogen-containing gas supply system in the common groove according to claim 1, further comprising gas stop means for stopping the supply of the hydrogen-containing gas in response to the alarm.   The hydrogen-containing gas supply system in a common groove according to claim 1 or 2, wherein the inner pipe is made of a polyethylene pipe, and the outer pipe is made of a polyvinyl chloride pipe.   The bent portion of the gas pipe has a joint body, the inner pipe is assembled in a state where the straight pipe of the inner pipe is fused via the elbow pipe, and the straight pipe of the outer pipe is projected outside. The hydrogen-containing gas supply system in the common groove according to any one of claims 1 to 3, which is connected by a joint.

Images