JPH09273693A - Pressure fluctuation absorbing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure fluctuation absorbing device capable of absorbing large pressure fluctuation without remarkably decreasing supplying capacity of fluid and without increasing an arranging space. SOLUTION: A pressure fluctuation absorbing device is provided with a chamber 12 as a pressure cushioning chamber provided on the way of a pipe 11 for transporting gas, an orifice member 13 arranged in a pipe 11 near an upstream inlet of the chamber 12, and an orifice member 14 as a throttle member arranged in the pipe 11 near a downstream outlet of the chamber 12. The chamber 12 has the capacity equivalent to capacitance of an electric circuit, and the orifice members 13, 14 have resistance equivalent to that of the electric circuit. Combination of respective elements constitutes an RC circuit and acts as a kind of an acoustic filter, and therefore, pulsative pressure fluctuation to be propagated from the fluctuation pressure source side is effectively absorbed, and amplitude of the pulsation can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure fluctuation absorbing device for absorbing pressure fluctuations in a fluid transportation pipe.

[0002]

2. Description of the Related Art Generally, when fluid such as gas or air is transported by piping, pressure fluctuations often occur in the piping. Such a pressure fluctuation is also caused by a gas consuming device such as a GHP (gas engine type heat pump; commonly known as a gas heat pump) that performs cooling and heating by operating a compressor for compressing a refrigerant by a gas engine. This GHP
For this, a reciprocating gas engine that normally sucks gas at the same time as the atmosphere during the intake cycle and then compresses and explodes is used, but since gas intake in this case is performed intermittently, there is a periodic Pressure pulsations occur.
The amplitude of this pressure pulsation is 100 to ₃ when the average gas supply pressure is 220 mmH ₂ O as shown in FIG. 7, for example.
It can reach up to 00 mmH ₂ O.

[0003] Such a gas pressure fluctuation in the pipe propagates in the pipe to the upstream side, and may adversely affect the operation of a gas meter or other equipment arranged upstream. For example, in the case of a gas meter that measures the amount of transported gas by converting the flow rate of gas into a flow rate, the flow rate also fluctuates due to fluctuations in gas pressure, which causes an adverse effect such that an accurate gas flow rate cannot be obtained. Further, such a gas pressure fluctuation may affect the durability of the current membrane-type positive displacement gas meter or the like. Therefore, measures are needed to reduce such gas pressure fluctuations.

FIG. 8 shows a typical arrangement of GHPs. As shown in this figure, a valve 102 is provided on the downstream side of the gas meter 101 attached to the user's house.
A GHP 104 is arranged via the pressure fluctuation absorbing device 103.

As the pressure fluctuation absorbing device 103, for example, as shown in FIG. 9, there is one in which a chamber (fluid chamber) 106 as a buffer (tank) is formed in a part of a pipe 105. In this case, the chamber 106 is equivalent to the capacity in the electric circuit and acts as a kind of acoustic filter to absorb the pressure fluctuation in the pipe.

Further, as another example of the pressure fluctuation absorbing device 103, there is one in which an orifice member 107 for narrowing the flow path in the pipe 105 is arranged as shown in FIG. The orifice member 107 in this case is equivalent to the resistance in the electric circuit. Therefore, the orifice member 107 acts as a kind of acoustic filter and absorbs the pressure fluctuation in the pipe.

Further, it has been practiced that the valve 102 is half opened without providing the pressure fluctuation absorbing device 103, and the same operation as that of the orifice member 107 of FIG. 10 is performed.

[0008]

As described above, conventionally,
A buffer (tank) or an orifice member (throttle) is independently inserted and arranged on the upstream side of a fluctuating pressure source such as GHP, or the valve on the upstream side of the fluctuating pressure source is squeezed to a half-opened state to achieve the same effect as the orifice member. Was being done. However, in order to sufficiently absorb the pressure fluctuations only by the chamber, it is necessary to considerably increase the volume of the chamber (about several tens of liters), which causes problems in terms of piping equipment and cost. On the other hand, if it is attempted to absorb the pressure fluctuations only with the orifice member, it is necessary to considerably reduce the diameter of the orifice member, resulting in an increase in resistance and an increase in pressure loss in the flow path, which significantly reduces the gas transport capacity of the pipe. There was a problem that it would end up. This point poses a similar problem in the method of reducing the valve.

Further, when the pressure fluctuation is considerably large,
There is a problem that the pressure fluctuation cannot be sufficiently absorbed only by the orifice member or the chamber, and the function as the pressure fluctuation absorbing device cannot be sufficiently exhibited.

The present invention has been made in view of the above problems, and an object thereof is to absorb a considerably large pressure fluctuation without causing a significant decrease in fluid transportation capacity and an increase in installation space, and to reduce the pressure inside the pipe. Another object of the present invention is to provide a pressure fluctuation absorbing device capable of stabilizing the above.

[0011]

A pressure fluctuation absorbing device according to claim 1 is arranged on the upstream side of a pipe of a fluid consuming device, and absorbs a fluid pressure fluctuation generated in the pipe by the operation of the fluid consuming device. An apparatus is provided with a pressure buffer chamber having a predetermined capacity, and a throttle member having an opening of a predetermined size provided on at least one of an inlet side and an outlet side of the pressure buffer chamber. In this pressure fluctuation absorbing device, the combination of the pressure buffer chamber and the throttle member forms a kind of acoustic filter, and it is possible to absorb a large pressure fluctuation as compared with the case of using them individually.

A pressure fluctuation absorbing device according to a second aspect is the pressure fluctuation absorbing device according to the first aspect, wherein the pressure buffer chamber is
It is configured as a tubular body that connects the upstream side pipe and the downstream side pipe, and the throttle member is disposed in a pipe joint structure that connects the tubular body with the upstream side pipe and the downstream side pipe. In this pressure fluctuation absorbing device, the pressure buffer chamber is configured as a tubular body, and the throttle member is disposed in the pipe joint structure on both sides of the tubular body, so a large installation space that does not exceed the pipe diameter is not taken. It is easy to install.

A pressure fluctuation absorbing apparatus according to a third aspect of the present invention is applied to the pressure fluctuation absorbing apparatus according to the first aspect when the fluid consuming device is a gas engine heat pump. In this pressure fluctuation absorbing device, it is possible to absorb the pressure fluctuation having a large pulsation amplitude generated by the operation of the gas engine heat pump.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an example in which a pressure fluctuation absorbing device according to an embodiment of the present invention is applied to a city gas transportation pipe, and shows a cross section in the longitudinal direction of the pipe.

This pressure fluctuation absorbing device is provided in a chamber (fluid chamber) 12 as a pressure buffer chamber provided on the way in the pipe 11 for gas transportation, and in the pipe 11 near the upstream inlet of the chamber 12. An orifice member 13 provided and an orifice member 14 as a throttle member disposed in the pipe 11 near the outlet on the downstream side of the chamber 12 are provided. Here, the upstream side means the gas supply side, and the downstream side means the gas consuming device (for example, GHP or the like) side, that is, the fluctuating pressure source side.

The pipe 11 and the chamber 12 are the pipe 11
Has a circular cross-sectional shape in a direction orthogonal to the longitudinal direction of the. The orifice member 13 is formed in a disk shape having a small hole 15 in the center, and is fixed so as to be orthogonal to the longitudinal direction of the pipe 11 to divide the inside of the pipe 11 into an upstream side and a downstream side. The small hole 15 is usually formed in a circular shape, but it may be rectangular or any other shape. The same applies to the orifice member 14.

Next, the operation of the pressure fluctuation absorbing device having the above structure will be described.

The chamber 12 is equivalent to the capacitance in the electric circuit, and the orifice members 13 and 14 are equivalent to the resistance in the electric circuit. The combination of these elements constitutes an RC circuit and acts as a kind of acoustic filter. Therefore, by appropriately setting the volume (volume) of the chamber 12 and the size of the small hole 15 of the orifice member 13 with respect to the inner diameter of the pipe 11 and the frequency of the fluctuating pressure, as shown in FIG. Effectively absorbs pulsating pressure fluctuation (a) propagating from the source side, and (b)
The pulsation amplitude can be reduced as shown in.

FIG. 3 shows an arrangement example when the pressure fluctuation absorbing device of FIG. 1 is applied to a GHP. As shown in this figure, the gas meter 2 installed in the user's house
1, a valve 22 and a pressure fluctuation absorbing device 23
The GHP 24 is disposed via the. The valve 22 is
The pressure fluctuation absorbing device 23 is provided to cut off the gas supply when the pressure fluctuation absorbing device 23 is installed or replaced, and is arranged in the pipe 11 on the upstream side of the pressure fluctuation absorbing device 23.

As shown in FIG. 4, the pressure fluctuation absorbing device 23 has a flexible pressure-resistant hose 31, and a pipe joint 32 for connecting between both ends of the pressure-resistant hose 31 and the upstream pipe 11 and the GHP 24. , 33 and. The pressure-resistant hose 31 is made of, for example, a rubber containing wire,
It functions as the chamber 12 in FIG.
Union joints are used as the pipe joints 32 and 33, for example. Each of the pipe joints 32 and 33 accommodates an orifice member (not shown in the drawing) described later, and these serve as the orifice member 14 in FIG.

FIGS. 5 and 6 show the structure of the pipe joint 32. Of these, FIG. 5 shows a cross-sectional configuration along the longitudinal direction (axial direction) of the pressure-resistant hose 31, and FIG. 6 shows a state viewed from the direction of arrow a in FIG. The same applies to the pipe joint 33.

As shown in these figures, the pipe joint 32
Is a connection fitting 41, a connection fitting 42, and a tightening fitting 43.
A packing 44 and an orifice member 45. The right end side of the connection fitting 41 is connected to the pressure resistant hose 31 (not shown), and the left end side of the connection fitting 42 is connected to the pipe 11 (not shown). A ring-shaped packing 44 is arranged on a concave step surface 49 formed along the circumference on the left end side of the connection fitting 41. The connection fitting 42 is arranged so that its right end surface contacts the packing 44. Fastening bracket 43
Is loosely fitted around the outer periphery of the connection fitting 41,
By screwing the female screw portion 45 formed on the inner periphery thereof into the male screw portion 46 formed on the outer periphery of the connection fitting 42 and tightening the stepped edge 47 formed along the inner peripheral surface of the fastening fitting 43. , The step edge 48 formed along the outer circumference of the connection fitting 41 is pressed in the left direction in the drawing, whereby the connection fitting 41 and the connection fitting 42 are inserted through the packing 44.
And can be concluded.

A concave step portion 51 is formed along the inner peripheral side on the right end side of the connecting fitting 42, and a disc-shaped orifice member 55 is arranged therein. On the other hand, on the left end side of the connection fitting 41, a convex step portion 52 with which the inner circumference of the packing 44 is fitted is formed. The orifice member 55 divides the space on the side of the connection fitting 41 and the space on the side of the connection fitting 42 in the state where the connection fitting 41 and the connection fitting 42 are fastened. A small hole 56 for narrowing the flow path is formed in the center of the orifice member 55. The size of the small hole 56 depends on the gas consumption of the GHP 24,
For example, it is about 5 mm.

The step amount of the concave step portion 51 of the connecting fitting 41 is A, the step amount of the convex step portion 52 of the connecting fitting 42 is B, the thickness of the packing 44 is t _p , and the thickness of the orifice member 55 is t. ₀ If, t ₀ are required to satisfy the following equation (1).

[0026] _{t 0 ≦ A + t p -B} ... (1)

It is necessary to satisfy the formula (1) when the connection fitting 41 and the connection fitting 42 are tightened, the orifice member 55 prevents the approach between the fittings and the packing 4.
This is to prevent incomplete gas sealing by No. 4. Therefore, also for this purpose, the orifice member 55
Is preferably made of a relatively soft material such as vinyl chloride or cork, and the packing 44 is preferably made of a relatively hard material such as paper or asbestos.

Next, the operation of the pressure fluctuation absorbing device having the above structure will be described.

The pressure-resistant hose 31 functions as the chamber 12 in FIG. 1 as described above, and the pipe joints 32 and 33 are provided.
1 respectively act as the orifice members 13 and 14 in FIG. 1, and as described with reference to FIG. 1, the combination of these members constitutes an RC circuit and acts as a kind of acoustic filter. Therefore, the fluctuating pressure source side (GHP
The pulsating pressure fluctuation propagating from 24) can be effectively absorbed, and the influence on the gas meter 21 can be reduced.

The damping characteristic of the pressure fluctuation in this case is as follows:
Although it is related to the inner diameter of 1, the amount of gas consumed by the GHP 24, and the cycle of fluctuating pressure caused thereby, by appropriately setting the capacity (volume) of the pressure resistant hose 31 and the size of the small hole 56 of the orifice member 55, It is quite possible to obtain the pressure fluctuation amplitude damping characteristic of the period. The capacity of the pressure-resistant hose 31 (volume in the pipe) is set to, for example, about several hundred milliliters to several liters. . The diameter of the small hole 56 is, for example, 5 mm.
It is set to a degree.

As described above, in the present embodiment, the pressure fluctuation absorbing device is configured not only by the capacity (chamber) but by combining the capacity and the resistance (orifice). The diameter of the chamber 12 in FIG. 1 does not have to be equal to or larger than the diameter of the pipe 11 as long as the desired damping characteristic is obtained, and can be made substantially the same as the diameter of the pipe 11. Therefore, the piping space does not increase.

Further, in the pressure fluctuation absorbing apparatus shown in FIG. 4, the pressure resistant hose 31 is used as the chamber, and
Since the orifice member 55 is incorporated in the pipe joints 32 and 33, the facility cost can be reduced and
It does not require a large installation space. Also, GHP24
The length of the pressure-resistant hose 31 or the small hole 5 of the orifice member 55 may be changed as necessary, such as when the pressure gauge is replaced with another specification.
Since it is easy to change the size of 6, the quick and appropriate response according to the gas consumption amount of the gas consuming device, the pressure fluctuation cycle, and the like becomes possible.

Although the present invention has been described above with reference to some embodiments, the present invention is not limited to these embodiments and can be variously modified within the equivalent range. For example, in the present embodiment, the orifices are provided on both the upstream side and the downstream side of the chamber. However, depending on the amplitude of the pressure fluctuation, even if the orifices are arranged in only one of them, the desired damping characteristics can be obtained. It is possible to obtain.

The valve 22 in FIG. 3 is a GHP.
In principle, the valve 24 should be fully opened during use, but if the pressure fluctuation in the pipe is particularly large, it is also possible to restrict the valve 22 to the half-opened state within a range that does not hinder the gas supply amount to the GHP 24. .

[0035]

As described above, according to the pressure fluctuation absorbing device of the first aspect, the pressure buffer chamber and the throttle member are combined to form a kind of acoustic filter.
The pressure inside the pipe can be stabilized by absorbing a considerably large pressure fluctuation without causing a significant decrease in the fluid transport capacity due to the pressure loss and an increase in the installation space.

According to the pressure fluctuation absorbing apparatus of the second aspect, the pressure buffer chamber is formed as a tubular body, and the throttle members are arranged in the pipe joint structure on both sides of the tubular body. No special work or processing required when arranging a pressure buffer chamber or a throttle member in the pipe is required, and simply work to attach the tubular body to the pipe using the pipe joint containing the throttle member. All you have to do is do it. Therefore, construction is extremely simple, and removal and replacement are easy. Further, since the tubular body itself constitutes the pressure buffer chamber, a projecting space that exceeds the diameter of the pipe, which is conventionally required to mount the pressure buffer chamber, is not required, and compact construction is possible.

According to the pressure fluctuation absorbing apparatus of the third aspect, since the constitution of the combination of the pressure buffer chamber and the throttle member is applied to the gas engine heat pump, it is applicable to the intake, compression and explosion cycles of the gas engine. Even if a pulsating large-amplitude pressure fluctuation occurs, it can be effectively absorbed, and the influence on the equipment such as the gas meter arranged on the upstream side can be suppressed to the minimum.

[Brief description of drawings]

FIG. 1 is a cross-sectional view along a pipe longitudinal direction showing a configuration of a pressure fluctuation absorbing device according to an embodiment of the present invention.

FIG. 2 is a waveform diagram for explaining a pressure fluctuation reducing state by the pressure fluctuation absorbing device of FIG.

FIG. 3 is a diagram showing an arrangement example of the pressure fluctuation absorbing device of FIG.

FIG. 4 is a diagram showing an application example of the pressure fluctuation absorbing device of FIG.

5 is a cross-sectional view showing the structure of the pipe joint of FIG.

FIG. 6 is a diagram showing a state in which the pipe joint of FIG. 5 is viewed from a direction of an arrow a.

FIG. 7 is a diagram showing an example of pressure fluctuation in a pipe.

FIG. 8 is a diagram showing an arrangement example of a conventional pressure fluctuation absorbing device.

FIG. 9 is a diagram illustrating a configuration example of a conventional pressure fluctuation absorbing device.

FIG. 10 is a diagram illustrating another configuration example of a conventional pressure fluctuation absorbing device.

[Explanation of symbols]

 11 Piping 12 Chamber 13, 14, 55 Orifice Member 15,56 Small Hole 21 Gas Meter 22 Valve 23 Pressure Fluctuation Absorber 24 GHP (Gas Engine Heat Pump) 31 Pressure Resistant Hose 32, 33 Piping Joint 41, 42 Connection Fitting 43 Clamping Fitting 44 Packing

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shinichi Sato 543-15 Kitanocho, Hachioji-shi, Tokyo

Claims (3)

[Claims] 1. A device for absorbing a fluid pressure fluctuation generated in a pipe due to the operation of the fluid consuming device, the device being arranged on the upstream side of the fluid consuming device, the pressure buffer chamber having a predetermined capacity. A pressure fluctuation absorbing apparatus, comprising: a throttle member having an opening of a predetermined size provided on at least one of an inlet side and an outlet side of the pressure buffer chamber. 2. The pressure buffer chamber is configured as a tubular body that connects the upstream pipe and the downstream pipe, and the throttle member is a pipe that connects the tubular body to the upstream pipe and the downstream pipe. The pressure fluctuation absorbing device according to claim 1, wherein the pressure fluctuation absorbing device is arranged in a joint structure. 3. The pressure fluctuation absorbing device according to claim 1, wherein the fluid consuming device is a gas engine heat pump.