JP2002195055A - Pressure pulsation suppressing device, gas fuel consumption device provided with the same, and its operation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure pulsation suppressing device having a possibility of receiving fuel supply from a low-pressure gas supply line and effectively moderating the pressure pulsation generated by a gas fuel consuming device, having high fuel consumption rate (for example, a microgas turbine), without receiving the output limit and causing delay in startup. SOLUTION: A first channel 13 and a second channel 14 are made to coexist in between an inlet pipe 11 connected to a fuel gas supply line 1 and an outlet pipe 12 connected to a fuel gas inlet 21 of the gas fuel consuming device 20. An orifice 15 is disposed in the first channel 13, and a prescribed capacity of surge tank 16 and a cutoff valve 17 are disposed in the second channel 14. In starting, the cutoff valve 17 is closed, and gas fuel is supplied to the gas fuel consuming device 20 only via the orifice 15, and at stable operation, the cutoff valve 17 is opened and a large quantity of fuel gas is supplied through the surge tank 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention alleviates the pressure pulsation of a fluid such as a fuel gas generated on the side of a gas fuel consuming device, and the gas pressure fluctuation affects an upstream fuel gas fluid supply line. TECHNICAL FIELD The present invention relates to a pressure pulsation suppressing device configured to suppress the occurrence of pressure, a gas fuel consuming device provided with the device, and a method of operating the same.

[0002]

2. Description of the Related Art Generally, when a fluid such as gas or air is transported through a pipe, it is necessary to suppress a pressure fluctuation occurring in the pipe. Such a pressure fluctuation may occur due to, for example, a gas fuel consuming device connected to a gas supply line. When the gas fuel consuming device is, for example, a gas engine type heat pump, a reciprocating gas engine is usually used as the gas engine. Pulsation occurs. The amplitude of the pressure pulsation, when the average gas supply pressure is 220mmH ₂ O, 100~300
mmH ₂ O in some cases.

[0003] Such gas pressure fluctuations propagate through the gas supply line to the upstream side, and may adversely affect other gas fuel consuming devices such as a water heater and a gas stove disposed on the upstream side. . As a countermeasure for this, the present applicant has already proposed a pressure fluctuation absorbing device 50 as shown in FIG. The pressure fluctuation absorbing device 50 is developed mainly for a gas engine heat pump (GHP), and includes a tank 51 as a pressure buffer chamber provided on a fuel pipe 61 for gas transport, This tank 51
A first orifice 52a disposed in the fuel pipe 61 near the upstream inlet 53 and a second orifice 52b disposed in the fuel pipe 61 near the outlet 54 downstream of the tank 51. It has. The fuel pipe 61 provided with the second orifice 52 is connected to the gas engine via a pressure regulator and a mixer. In the gas engine type heat pump, periodic gas pressure pulsation occurs in the fuel pipe 61 because gas is intermittently taken as described above.
Since the amplitude of the pressure pulsation is effectively absorbed by the pressure fluctuation absorbing device 50, the pressure in the gas supply line can be stabilized, and the pressure fluctuation generated due to the gas engine heat pump is reduced to the upstream side. Adversely affecting other gas-fuel-consuming devices and the like arranged in the vehicle.

[0004]

The pressure fluctuation absorbing device of the above type does not need to be used after the fuel gas has been pre-pressurized by a compressor, unlike a gas engine heat pump.
In the case of gas fuel consuming equipment that consumes a relatively small amount of fuel gas, it is highly effective as a device for suppressing pressure fluctuations on the upstream side, and causes a particular problem in the operation of gas fuel consuming equipment. I will not let you. However, it is not necessarily effective for a gas fuel consuming device such as a gas turbine which requires a high pressure and a large amount of fuel gas for operation. The reason is, as shown, the orifice 52a,
In a device in which the tank 51 and the orifice 52b are arranged in series, even if the function of suppressing pressure pulsation works effectively, the pressure loss due to the orifice limits the maximum flow rate of the fuel gas, and the gas fuel consuming device side This is because the output may be limited or the rise time until reaching a steady state may be delayed.

In recent years, a micro gas turbine having an output of about 100 kW or less has been developed and is being put to practical use. Since the micro gas turbine is small and has a small output, it is fully conceivable that the micro gas turbine is used for practical operation in an urban area or the like while being supplied with a fuel gas from a low-pressure gas supply line such as a city gas. As described above, a micro gas turbine requires a large amount of high-pressure gas even though it is small. For this purpose, the micro gas turbine is provided with a large-capacity compressor and a receiver tank, and is operated in a state in which the compressor absorbs and compresses a large amount of low-pressure gas and stores high-pressure gas in the receiver tank.
Accordingly, it is not effective to use a pressure fluctuation absorbing device having an orifice and a tank arranged in series as shown in FIG. 7 for a gas fuel consuming device having such an operation mode.

The present invention has been made in view of the above circumstances, and is intended to provide a gas fuel consuming device which may receive fuel from a low pressure gas supply line and consumes a large amount of fuel. The pressure pulsation caused by the gas fuel consuming device is reduced without limiting the output or delaying the start-up, so that the influence of the pressure fluctuation on the fuel gas supply line on the upstream side is reduced. It is an object of the present invention to provide a pressure pulsation suppressing device capable of effectively suppressing pressure, a gas fuel consuming device equipped with the device, and a method of operating the device.

[0007]

According to the present invention, there is provided a pressure pulsation suppressor installed on a fuel gas inlet side of a gas fuel consuming apparatus, comprising an inlet pipe connected to a fuel gas supply line and a fuel gas inlet of the gas fuel consuming apparatus. A first flow path and a second flow path coexist between the inlet pipe and the outlet pipe; the first flow path includes an orifice; The second flow path includes a surge tank having a required capacity, and further includes flow path closing means capable of closing at least the second flow path. The flow path closing means may be a shutoff valve provided in the second flow path, or may be a switching valve for switching the flow of the fuel gas between the first flow path and the second flow path.

In the present invention, an orifice is a general term for an orifice having a function of giving a required throttle resistance to a gas flow flowing through a fuel gas flow pipe employed in the pressure pulsation suppressing device. For example, a pipe member having a smaller diameter than the fuel gas flow pipe constituting the first flow path or a porous material having air permeability inserted into the fuel gas flow pipe may be used. In the case of, not only fixed orifices but also movable orifices are included.

In the operation of the gas fuel consuming equipment having the pressure pulsation suppressing device according to the present invention, before starting, the shutoff valve or the switching valve as the flow path closing means is operated to operate the second fuel tank equipped with the surge tank. The flow path is closed, and the fuel gas is set to flow only into the first flow path provided with the orifice. When the gas fuel consuming equipment is started in that state,
Since the fuel gas passage on the gas fuel consuming device opens instantaneously, significant pressure fluctuation occurs instantaneously. However, the pressure fluctuation is suppressed by the effect of the orifice provided in the first flow path, and then propagates to the gas supply line on the upstream side, so that it adversely affects other gas fuel consuming devices on the upstream side. Never.

[0010] After a predetermined time elapses, required operation preparation on the gas fuel consuming equipment side (for example, a normal fuel consumption starting state).
When is established, the flow path closing means is operated to open the second flow path. The first flow path may be left open or closed. Since the second flow path has no orifice, the gas flow rate required by the gas fuel consuming device can be secured, and the presence of the pressure pulsation suppressor causes the gas fuel consuming device side to delay start-up and limit output. There is no adverse effect. Pressure fluctuations such as pulsations generated by a compressor or the like during the steady operation of gas fuel consuming equipment are caused by the second
The gas is absorbed by the surge tank provided in the flow path, and does not adversely affect other gas fuel consuming devices on the upstream side.

Preferably, the gas fuel consuming device has an appropriate state quantity (for example, an operation mode,
The sensor further includes a sensor for detecting the output, the number of rotations, etc.) or a pressure sensor for detecting the pressure at the outlet of the surge tank, and a control means for operating the flow path closing means by a signal from the sensor. By providing such a sensor and a control means, a more optimized pressure pulsation suppression effect according to the operating state of the gas fuel consuming device can be obtained.

In the present invention, there is no limitation on the target gas fuel consuming equipment. However, it is particularly effective to equip a device that consumes a large amount of high-pressure gas, for example, a micro gas turbine with the pressure fluctuation absorbing device according to the present invention.
Usually, a micro gas turbine is provided with a shut-off valve, for example, an electromagnetic valve, a compressor, and a receiver tank between a fuel gas inlet and a fuel gas consuming section (combustor). The compressed fuel gas is stored at a pressure higher than the pressure at the fuel gas inlet, and the high-pressure gas is sent to a fuel gas consuming unit (combustor). For this reason, a compressor having a large capacity and a high compression ratio is used, and the amplitude of the pressure pulsation is large together with the pressure fluctuation immediately after opening of the shut-off valve at the time of starting. Therefore, the pressure pulsation suppression device according to the present invention, in which the flow path is switched between at the time of start-up and at the time of steady-state operation, functions particularly effectively, for example, another low-pressure gas supply line provided in the upstream gas line. The effect on gas fuel consuming equipment and the like can be effectively prevented.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an example in which a pressure pulsation suppressing device 10 according to one embodiment of the present invention is applied to a gas fuel consuming device, for example, a micro gas turbine 20. As shown in FIG. 2, the micro gas turbine 20 includes an electromagnetic valve 23, a compressor 24, and a receiver tank 25 between a fuel gas inlet 21 and a combustor 22 as a fuel gas consuming unit. The pressure 25 is higher than the pressure at the fuel gas inlet 21 after being compressed by the compressor 24 (for example, 300 kPa (3 kg / cm
² )) The stored fuel gas is stored, and the high-pressure gas is sent to the combustor 22. The high-pressure combustion gas in the combustor 22 is sent to a turbine 26 to drive a generator 27, and then is discharged through a heat exchanger 28. The combustion air is turbine 26
After being compressed by the heat exchanger 28, it is preheated through the heat exchanger 28 and supplied to the combustor 22.

The pressure pulsation suppressor 10 is connected to an inlet pipe 11 connected to the low-pressure gas supply line 1, which is a city gas supply pipe in this example via a meter 1 a, and a fuel gas inlet 21 of the micro gas turbine 20. An outlet pipe 12 is provided, and a first flow path 13 is provided between the inlet pipe 11 and the outlet pipe 12.
And the second flow path 14 coexist. The first flow path 13 has an orifice 15 having a diameter smaller than the pipe diameter and functioning as a throttle for a gas flow flowing therethrough. The second flow path 14 has a micro gas turbine A surge tank 16 having a capacity capable of absorbing pressure fluctuations or pressure pulsations generated at the side 20 is provided, and a shutoff valve 17 is provided upstream of the surge tank 16.

Reference numeral 18 denotes a control device for the shut-off valve 17, which is an operation state quantity detection sensor 3 provided in the micro gas turbine 20.
By taking in the signal from 0 and the signal of the pressure sensor 31 arranged immediately downstream of the surge tank 16, the opening / closing control of the shutoff valve 17 is performed. The degree of restriction by the orifice 15 and the size of the capacity of the surge tank 16 are determined by the magnitude of the pressure fluctuation at the time of starting the gas fuel consuming device (for example, the micro gas turbine 20) and the actual pressure pulsation generated during the steady operation. It is appropriately selected according to the magnitude of the amplitude.

Next, the operation of the pressure pulsation suppressing device 10 will be described in relation to the operation of the micro gas turbine 20.
Before starting the micro gas turbine 20, the shut-off valve 17
Is operated to close the shut-off valve 17 and open only the first flow path 13 provided with the orifice 15. At that time, the solenoid valve 23 on the micro gas turbine 20 side is also closed. In that state, the fuel gas to be supplied is at rest (normal pressure).

When an operation start command is issued to the micro gas turbine 20, the solenoid valve 2 of the micro gas turbine 20
3 is opened, the first flow path 13 communicates with the flow path from the compressor 24 of the micro gas turbine 20, the receiver tank 25, and the combustor 22 via the outlet pipe 12, and a remarkable pressure fluctuation occurs instantaneously. However, the pressure fluctuation is suppressed by the effect of the orifice 15 provided in the first flow path 13 and hardly affects the gas supply line 1 on the upstream side.

The operation of the compressor 24 starts and the accumulation of the pressure in the receiver tank 25 starts. Pressure pulsation caused by the compressor 24 occurring during this time is also suppressed by the effect of the orifice 15, and the pressure in the gas supply line 1 on the upstream side is slightly reduced, but a stable state is maintained.
Operating state sensor 30 provided in micro gas turbine 20
Is set in the receiver tank 2 within a certain time (for example, one minute).
When fuel gas of a predetermined pressure (for example, 300 kPa) is accumulated in the pump 5, it is determined that normal operating conditions are satisfied, and a signal for starting operation is sent to the controller 18, and the shutoff valve 17 is switched to the open state.

As a result, the fuel gas flows through the second flow path 14 and flows into the compressor side circuit of the micro gas turbine 20, and the micro gas turbine 20 shifts to a full operation (steady operation) state. Second flow path 14
Does not have a member (orifice) that resists the flow, so that the gas flow rate required by the micro gas turbine 20 can be easily secured. For this reason, the micro gas turbine 20 is not adversely affected by a delay in start-up, output limitation, or the like.

When the micro gas turbine 20 enters the steady operation state, the pressure pulsation from the compressor 24 becomes more apparent. However, the pressure pulsation is absorbed by the surge tank 16 provided in the second flow passage 14 and the pressure pulsation is absorbed. While driving,
The gas supply line 1 on the upstream side has almost no effect. Therefore, there is no adverse effect on other gas fuel consuming devices on the upstream side.

At the end of operation, the micro gas turbine 2
At 0, an operation end command is issued. As a result, a stop signal for fuel gas consumption is issued, and the micro gas turbine 20 is stopped.
Solenoid valve 23 is closed. At the same time, a signal from the operation state quantity detection sensor 30 is sent to the control device 18 and the shut-off valve 17
To close. Thereby, the operation of the micro gas turbine 20 ends, and the pressure pulsation suppression device 10 also returns to the state before the start.

The opening / closing timing and opening degree of the shut-off valve 17 provided in the pressure pulsation suppressing device 10 are controlled by the operating state quantity detection sensor 30 provided in the micro gas turbine 20.
By taking in a state quantity representing an appropriate operation state from the above, the pressure suppression effect can be further optimized. Further, by controlling the opening of the shut-off valve 17 based on a signal from the pressure sensor 31 provided in the second flow path 14, the effect of suppressing pressure pulsation can be further increased.

Next, a description will be given of a pressure history in an operation actually performed by the present inventors using the apparatus shown in FIG. 1 together with a pressure history according to a comparative example. FIG. 3 shows the pressure in the low pressure gas supply line 1 on the upstream side when the micro gas turbine 20 is operated by directly connecting the low pressure gas supply line 1 to the fuel gas inlet 21 of the micro gas turbine (MGT) 20. Shows history. When the gas solenoid valve 23 is opened at the time of startup, a large pressure drop appears instantaneously, and thereafter, a considerable pressure fluctuation occurs even at the start of turbine operation. Further, even after the steady operation, pulsation of a considerable amplitude is always observed.

FIG. 4 shows the pressure fluctuation at start-up in the device shown in FIG. 1 (the device according to the invention).
Corresponds to the pressure fluctuation for several seconds after the solenoid valve is opened. The broken line indicates the fuel gas inlet 2 of the micro gas turbine 20.
The solid line represents the pressure history at the inlet of the meter 1a in the low-pressure gas supply line 1 equivalent to the inlet pipe 11 of the pressure pulsation suppression device 10. Although the opening of the solenoid valve 23 on the side of the micro gas turbine 20 and the subsequent operation of the compressor 24 cause a large pressure drop at the fuel gas inlet 21 of the micro gas turbine 20,
Due to the effect of the orifice 15 provided in the first flow path 13,
The effect of the pressure drop is hardly apparent on the low-pressure gas supply line 1 side.

FIG. 5 is a pressure history when the shut-off valve 17 is opened to enter a steady operation state. A pressure pulsation having a large amplitude from the compressor 24 (see FIG. 3) is provided in the second flow passage 14. It can be understood that the gas supply line 1 on the upstream side has almost no influence on the gas supply line 1 which is absorbed by the surge tank 16.

In the pressure pulsation suppressing device 10 shown in FIG. 1, the flow of the fuel gas into the second
This is performed by a shut-off valve 17 disposed in the flow path 14 of the first embodiment. However, a switching valve is disposed at a branch portion between the first flow path 13 and the second flow path 14 in the inlet pipe 11, and the switching valve is provided. Of course, the flow of the fuel gas into and out of the second flow path 14 may be performed by switching. Further, the first flow path and the second flow path need not be provided as flow paths completely branched between the inlet pipe 11 and the outlet pipe 12 in the pressure pulsation suppression device 10 as shown in FIG. Instead, the flow path may be a partially common flow path, and the surge tank 16 itself may constitute a part of the first flow path and the second flow path.

FIG. 6 shows the pressure pulsation suppressing device 1 of the above embodiment.
This shows one form of 0A, in which an inlet pipe 11 is arranged at one end of a cylindrical container 40 whose upper and lower ends are closed, and an outlet pipe 12 is arranged at the other end. Inside the container 50, a middle plate 41 covering the entire cross section is arranged. The middle plate 41 has a plurality of first openings 42 having a small diameter and a second opening 43 having a larger diameter than the first openings 42. Is formed. Further, a shutoff valve 40b which is moved up and down by an appropriate actuator 40a is accommodated in the container 40, and the shutoff valve 40b is
The second opening 43 is selectively set between an open state and a closed state by the vertical movement of b.

The space 44 below the middle plate 41 in the container 40, that is, the first space 44 connected to the inlet pipe 11, is referred to as the "first flow path" and the "second flow path" in the present invention. The path is a common path, and the space 45 above the middle plate 41, that is, the second space 45 connected to the outlet pipe 12 is also referred to as the “first flow path” in the present invention. And "second
Is a common passage, and can also function as a surge tank 16.
Further, the total cross-sectional area of the plurality of first openings 42 is equal to the inlet pipe 11.
The cross-sectional area of the second opening 43 is equal to or larger than the cross-sectional area of the inlet pipe 11.

When the gas fuel consuming device is started, as shown in FIG. 6A, the second opening 43 of the middle plate 41 is closed, and the fluid from the inlet pipe 11 receives the first opening formed in the middle plate 41. Through only 42 and into the second space 45,
It is led from the outlet pipe 12 to the gas fuel consuming device side. By appropriately setting the diameter and the number of the first openings 42 according to the pressure fluctuation at the time of starting, the first openings 42 appropriately fulfill a function corresponding to the orifice provided in the first flow path. Can be.

After a lapse of a predetermined time, the actuator 40a
To move the shutoff valve 40b in the opening direction. Thereby, the fuel gas flows from the second opening 43 having a large diameter, and the pressure loss of the fuel gas flowing through the pressure pulsation suppression device 10A substantially disappears, and the amount required by the gas fuel consuming device is reduced. Is supplied. In addition, the second space 45 has a large capacity, which functions as a surge tank and absorbs pressure fluctuations generated on the gas fuel consuming device side. Thereby, the influence of the pressure fluctuation is not transmitted to the inlet pipe 11.

The pressure pulsation suppressor 10A of this embodiment is compact and simple in construction, and can be handled as one unitized component. Therefore, one system is constructed by assembling with existing gas fuel consuming equipment. In this case, it becomes particularly preferable.

In the above description, a low-pressure gas supply line such as city gas is shown as an example of the fuel gas supply line. However, the pressure pulsation according to the present invention is provided between the medium-pressure gas supply line and the gas fuel consuming equipment. It goes without saying that the same effect can be obtained by connecting the suppression device.

[0033]

By using the pressure pulsation suppressing device according to the present invention, there is a possibility that a gas fuel consuming device may receive a fuel supply from a low pressure gas supply line like a micro gas turbine, and a fuel consumption amount may be reduced. Even if it is large, the pressure pulsation generated due to the gas fuel consuming device side can be effectively mitigated without restricting the output or delaying the rise, and the fuel gas supply line on the upstream side Can be effectively suppressed from being affected by the pressure fluctuation.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating an embodiment of a pressure pulsation suppressing device according to the present invention and a gas fuel consuming device including the same.

FIG. 2 is a schematic diagram illustrating a micro gas turbine as an example of a gas fuel consuming device.

FIG. 3 is a graph showing a pressure history generated during operation of a micro gas turbine when the pressure pulsation suppression device is not provided.

FIG. 4 is a graph showing a pressure history generated at the time of starting the micro gas turbine when the pressure pulsation suppressing device according to the present invention is provided.

FIG. 5 is a graph showing a pressure history generated during a steady operation of the micro gas turbine when the pressure pulsation suppressing device according to the present invention is provided.

6 is a view showing another embodiment of the pressure pulsation suppressing device according to the present invention, FIG. 6a shows a state at the time of startup, and FIG. 6b shows a state at the time of steady operation. FIG. 6C is a perspective view showing the middle plate.

FIG. 7 is a schematic diagram for explaining a pressure fluctuation absorbing device provided in a gas heat pump that has already been proposed.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Low pressure gas supply line, 10 ... Pressure pulsation suppression device, 1
DESCRIPTION OF SYMBOLS 1 ... Inlet pipe, 12 ... Outlet pipe, 13 ... 1st flow path, 14 ...
2nd flow path, 15 ... orifice, 16 ... surge tank,
17: shut-off valve, 20: gas fuel consuming equipment (micro gas turbine)

Claims (9)

[Claims] 1. A pressure pulsation suppressor installed on a fuel gas inlet side of a gas fuel consuming device, comprising: an inlet tube connected to a fuel gas supply line; and an outlet tube connected to a fuel gas inlet of the gas fuel consuming device. And between the inlet pipe and the outlet pipe,
A first flow path and a second flow path coexist, the first flow path includes an orifice, the second flow path includes a surge tank having a required capacity, and at least a second flow path. A pressure pulsation suppression device comprising a flow path closing means capable of closing a flow path. 2. The pressure pulsation suppression device according to claim 1, wherein said flow path closing means is a shut-off valve provided in a second flow path. 3. The pressure pulsation suppression device according to claim 1, wherein said flow path closing means is a switching valve for switching an inflow of fuel gas between a first flow path and a second flow path. 4. A gas fuel consuming device having the pressure pulsation suppressing device according to claim 1. 5. The gas fuel consuming device includes a shut-off valve, a compressor, and a receiver tank between a fuel gas inlet and a fuel gas consuming unit. 5. The gas fuel consuming apparatus according to claim 4, wherein the fuel gas having a pressure higher than the pressure of the fuel gas is stored. 6. The gas fuel consuming device according to claim 5, wherein the gas fuel consuming device is a micro gas turbine. 7. The gas fuel consuming device further includes a sensor for detecting an appropriate state quantity representing an operation state of the gas fuel consuming device, and a control unit for operating the flow path closing unit based on a signal from the sensor. The gas fuel consuming device according to any one of claims 4 to 6, wherein 8. The gas fuel consuming device further comprises a pressure sensor for detecting a pressure on the surge tank outlet side, and a control means for operating the flow path closing means by a signal from the pressure sensor. Claims 4 to 6
A gas fuel consuming device according to any of the preceding claims. 9. The method for operating a gas fuel consuming device according to claim 4, wherein the flow path closing means is operated to allow fuel gas to flow only into the first flow path at the time of startup. In addition, after a predetermined time has elapsed, the gas fuel consuming apparatus is characterized in that the fuel gas flows only into the second flow path or into both the first flow path and the second flow path to continue the operation. Driving method.