JPH0734898A - Energy recovery device of high pressure hydrogen gas - Google Patents

Abstract

PURPOSE:To almost eliminate the thrust force working on a drive shaft, and to remove a thrust bearing or to drastically reduce the size of the thrust bearing. CONSTITUTION:A double flow expander 8 for carrying out gas expansion from the intermediate part in the direction of a shaft to the both sides, is provided on a drive shaft 4 connected to a power generator 3, and an introduction tube 9 for introducing a high pressure hydrogen gas 2 is connected to the inlet 8a of the expander, while exhaust tubes 11 for exhausting a low pressure hydrogen gas 2' through a freezer/cooler 10 for cooling a heat exchanging medium 12, are connected to the outlets 8b, 8b of the expander 8. When the expander 8 is rotated and driven by introducing the high pressure hydrogen gas 2 cooler while the high pressure hydrogen gas 2 is expanded, the respective thrust forces generated from the inlet 8a of the expander 8 to the both outlets 8b, 8b work in the separating directions and are thus offset, and the thrust force working on the drive shaft 4 is thus almost eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an energy recovery system for high pressure hydrogen gas.

[0002]

2. Description of the Related Art In recent years, hydrogen gas has been attracting attention as a next-generation energy source, and assuming that hydrogen gas is actually used as fuel, etc., it is necessary to introduce hydrogen gas from a supply source such as a tank or a pipe. However, the hydrogen gas introduced at this time naturally has a high pressure in consideration of the storage efficiency of the tank, the transportation efficiency of the pipe, etc., and the pressure is too high to be used as it is as fuel or the like.

Therefore, as shown in FIG. 3, high-pressure hydrogen gas 2 introduced from a supply source such as a tank or a pipe through an introduction pipe 1.
Is introduced into the inlet 5a of the expander 5 provided on the drive shaft 4 of the generator 3, and the high-pressure hydrogen gas 2 introduced is expanded while being used as a pressure source for rotationally driving the expander 5, High pressure hydrogen gas 2 while effectively recovering the pressure energy of hydrogen gas 2 as electric energy
To a desired pressure, and the outlet 5 of the expander 5
An energy recovery device that supplies low-pressure hydrogen gas 2'from a discharge pipe 6 connected to b to a combustion facility (not shown) has been considered.

[0004]

However, in the energy recovery device as described above, when the high pressure hydrogen gas 2 is expanded by the expander 5, a large thrust force is applied from the inlet 5a side to the outlet 5b side of the expander 5. Therefore, a large thrust bearing 7 has to be provided at a required position on the drive shaft 4, which causes a problem in that the energy recovery device requires time and labor and the manufacturing cost rises.

Further, when the single-stage expander 5 shown in the drawing is used to suppress the thrust force when expanding the high-pressure hydrogen gas 2 as much as possible, the expansion degree of the high-pressure hydrogen gas 2 can be made large. There is also a problem that the pressure ratio between the high pressure hydrogen gas 2 before expansion and the low pressure hydrogen gas 2'after expansion is limited.

Further, when the high-pressure hydrogen gas 2 is expanded by the expander 5, the temperature of the hydrogen gas is remarkably lowered. Therefore, when the hydrogen gas is used as fuel or the like in the equipment on the downstream side, the temperature is too low. There was a problem that it was not easy to use.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an energy recovery device for high-pressure hydrogen gas that can solve all the problems described above at the same time.

[0008]

According to a first aspect of the present invention, there is provided gas expansion on a drive shaft connected to a generator from an axially intermediate portion to both sides or from axially both sides to an intermediate portion. A double-flow expander for performing the above is provided, an inlet pipe for introducing high-pressure hydrogen gas is connected to the inlet of the double-flow expander, and the outlet of the double-flow expander is passed through a refrigerating cooler for cooling the heat exchange medium. The invention relates to a high-pressure hydrogen gas energy recovery device, characterized in that a discharge pipe for discharging low-pressure hydrogen gas is connected, and the invention according to claim 2 of the present invention is a drive shaft connected to a generator. A high-pressure expander and a low-pressure expander, which perform gas expansion in opposite directions to each other, are provided respectively, and an inlet pipe for introducing high-pressure hydrogen gas to the inlet of the high-pressure expander is connected to the outlet of the high-pressure expander. The low-pressure expander inlet is connected via a connecting pipe through a re-cooling type refrigerating cooler for cooling the heat exchange medium, and the low-pressure expander outlet is connected via the re-cooling type refrigerating cooler. The present invention relates to a high-pressure hydrogen gas energy recovery device, which is connected to a discharge pipe for discharging low-pressure hydrogen gas.

[0009]

Therefore, according to the first aspect of the present invention, when the high-pressure hydrogen gas introduced through the introduction pipe is introduced into the inlet of the double-flow expander, the double-flow expander is generated by the pressure energy of the high-pressure hydrogen gas. Is rotationally driven, and its rotational force is transmitted to a generator via a drive shaft to generate electric power, and the high-pressure hydrogen gas is expanded by the double-flow expander to become low-pressure hydrogen gas and double-flow expander. It is discharged to the discharge pipe from the outlet of.

At this time, the thrust forces generated in the gas expansion direction of the double flow expander act in opposite directions to cancel each other, so that the thrust force acting on the drive shaft is almost lost.

Further, the low-pressure hydrogen gas discharged to the discharge pipe is heated to a temperature immediately after expansion by heat exchange with the heat exchange medium while passing through the refrigerating cooler and supplied to the combustion equipment or the like. The heat exchange medium that has undergone heat exchange with the low-pressure hydrogen gas immediately after expansion in the refrigerating cooler is supplied to equipment having low-temperature heat demand as a low-temperature cooling medium.

According to the second aspect of the present invention, when the high-pressure hydrogen gas introduced through the introduction pipe is introduced into the inlet of the high-pressure expander, the high-pressure hydrogen gas causes the high-pressure expander to operate. While being driven to rotate, the high-pressure expander expands the high-pressure hydrogen gas.

Further, the expanded hydrogen gas is introduced into the connecting pipe from the outlet of the high pressure expander, and immediately after expansion in the high pressure expander by heat exchange with the heat exchange medium while passing through the recooling type refrigerating cooler. Is introduced into the inlet of the low-pressure expander is raised from the temperature of, the low-pressure expander is rotationally driven by the pressure energy of the introduced hydrogen gas, the hydrogen gas is further expanded by the low-pressure expander, It becomes low-pressure hydrogen gas and is discharged to the discharge pipe from the outlet of the low-pressure expander.

At this time, the thrust force generated in the high-pressure expander and the thrust force generated in the low-pressure expander act in opposite directions to cancel each other, so that the thrust force acting on the drive shaft is almost lost. .

Further, the low-pressure hydrogen gas discharged to the discharge pipe is heated from the temperature immediately after expansion due to heat exchange with the heat exchange medium while passing through the recooling type refrigerating cooler again, and the combustion equipment is heated. Etc., on the other hand, in the re-cooling type refrigeration cooler, heat was exchanged twice with hydrogen gas immediately after expansion from the high pressure expander and low pressure hydrogen gas immediately after expansion from the low pressure expander. The heat exchange medium is supplied as a cryogenic cooling medium to equipment that has a cryogenic heat demand.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the invention described in claim 1 of the present invention, and the portions denoted by the same reference numerals as those in FIG. 3 represent the same things.

As shown in the figure, a double flow expander 8 for expanding gas from the axially intermediate portion to both sides is provided on the drive shaft 4 connected to the generator 3, and the axially intermediate portion of the double flow expander 8 is provided. An inlet pipe 9 for guiding the high-pressure hydrogen gas 2 from a supply source such as a tank or a pipe (not shown) is connected to the inlet 8a of the double-flow expander 8 at the outlets 8b and 8b on both sides in the axial direction. A discharge pipe 11 for discharging the low-pressure hydrogen gas 2 ′ to a combustion facility or the like (not shown) is connected via a refrigerating / cooling device 10 for cooling the.

When the high-pressure hydrogen gas 2 introduced from the supply source such as a tank or a pipe through the introduction pipe 9 is introduced into the inlet 8a of the double flow expander 8, the pressure energy of the high-pressure hydrogen gas 2 causes The double flow expander 8 is rotationally driven, the rotational force is transmitted to the generator 3 via the drive shaft 4 to generate electric power, and the high-pressure hydrogen gas 2 is applied to both sides of the double flow expander 8 in the axial direction. It is branched and expanded, respectively, and becomes low-pressure hydrogen gas 2 ', which is discharged from the outlets 8b, 8b to the discharge pipe 11.

At this time, the thrust forces generated from the inlet 8a of the double flow expander 8 toward both outlets 8b, 8b act in directions away from each other and cancel each other out, so that they act on the drive shaft 4. The thrust force is almost lost.

Further, the low-pressure hydrogen gas 2'exhausted into the exhaust pipe 11 is heated to a temperature immediately after expansion due to heat exchange with the heat exchange medium 12 while passing through the refrigerating cooler 10, and combustion equipment, etc. On the other hand, the heat exchange medium 12 that has been heat-exchanged with the low-pressure hydrogen gas 2 ′ immediately after expansion in the refrigerating cooler 10 is supplied as a low-temperature cooling medium 12 ′ to equipment with low-temperature heat demand. .

Therefore, according to this embodiment, the high-pressure hydrogen gas 2
Since the high-pressure hydrogen gas 2 can be depressurized to a desired pressure while effectively recovering the pressure energy possessed by the electric power energy, and the thrust force acting on the drive shaft 4 can be almost lost, the thrust bearing 7 ( Figure 3
(Refer to FIG. 4) can be removed or the size can be remarkably reduced, the labor for manufacturing can be remarkably reduced, and the manufacturing cost can be significantly reduced.

If the balance of the thrust forces generated from the inlet 8a of the double flow expander 8 toward both outlets 8b, 8b is maintained, the size of the double flow expander 8 can be increased without any particular limitation. Therefore, the expansion degree of the high-pressure hydrogen gas 2 can be increased as compared with the conventional single-stage expander 5 (see FIG. 3), and the high-pressure hydrogen gas 2 before expansion and the low-pressure hydrogen gas 2 after expansion can be obtained. 'The pressure ratio restriction with can be greatly relaxed.

Further, the low pressure hydrogen gas 2'expanded by the double flow expander 8 and lowered in temperature is discharged from the exhaust pipe 1.
1, the heat exchange medium 1 while passing through the refrigerating cooler 10
Since the temperature can be raised by exchanging heat with 2, it can be used favorably as a fuel or the like without a temperature problem by supplying it to a downstream combustion facility or the like.

On the other hand, the heat exchange medium 12 that has exchanged heat with the low-pressure hydrogen gas 2 ′ immediately after expansion in the refrigerating and cooling device 10.
Can be effectively used by supplying it as a low-temperature cooling medium 12 'to equipment with low-temperature heat demand.

FIG. 2 shows an embodiment of the invention according to claim 2 of the present invention, in which a high pressure expander 13 for performing gas expansion in opposite directions on a drive shaft 4 connected to a generator 3 is provided.
And a low-pressure expander 14, respectively, and an introduction pipe 1 for introducing high-pressure hydrogen gas 2 to the inlet 13a of the high-pressure expander 13.
5, the outlet 13b of the high-pressure expander 13 and the inlet 14a of the low-pressure expander 14 are connected to each other by the heat exchange medium 12
The low pressure hydrogen gas 2 ′ is connected to the outlet 14 b of the low pressure expander 14 via the recooling refrigerating cooler 16 and is connected via a communication pipe 17 passing through the recooling refrigerating cooler 16. A discharge pipe 18 for discharging the is connected.

In the case of this embodiment, the high-pressure hydrogen gas 2 introduced from a supply source such as a tank or a pipe through the introduction pipe 15
Is introduced into the inlet 13a of the high-pressure expander 13, the high-pressure expander 13 is rotationally driven by the pressure energy of the high-pressure hydrogen gas 2, and the high-pressure hydrogen gas 2 is expanded by the high-pressure expander 13.

Further, the expanded hydrogen gas is introduced from the outlet 13b of the high-pressure expander 13 to the connecting pipe 17, and while passing through the re-cooling type refrigerating cooler 16, the high-pressure extract is obtained by heat exchange with the heat exchange medium 12. The temperature is raised from the temperature immediately after expansion in the panda 13 and introduced into the inlet 14a of the low-pressure expander 14, and the low-pressure expander 14 is rotationally driven by the pressure energy of the introduced hydrogen gas 2, and the low-pressure expander is also driven. The hydrogen gas 2 is further expanded by the expander 14 to become low-pressure hydrogen gas 2 ', which is discharged from the outlet 14b of the low-pressure expander 14 to the discharge pipe 18.

At this time, the thrust force generated in the high-pressure expander 13 and the thrust force generated in the low-pressure expander 14 act in directions in which they are separated from each other and cancel each other, so that the thrust force acting on the drive shaft 4 is Almost lost.

Further, the low-pressure hydrogen gas 2 ′ discharged to the discharge pipe 18 rises above the temperature immediately after expansion due to heat exchange with the heat exchange medium 12 while passing through the recooling type refrigerating cooler 16 again. The gas is heated and supplied to a combustion facility or the like, while the hydrogen gas 2 immediately after expansion from the high-pressure expander 13 and the low-pressure hydrogen gas 2 ′ immediately after expansion from the low-pressure expander 14 in the re-cooling type refrigerating cooler 16 are supplied. On the other hand, the heat exchange medium 12 that has been heat-exchanged twice is supplied to the equipment having a cryogenic heat demand as the cryogenic cooling medium 12 '.

Therefore, according to this embodiment, as shown in FIG.
Similarly to the embodiment described above, the high-pressure hydrogen gas 2 can be depressurized to a desired pressure while effectively recovering the pressure energy of the high-pressure hydrogen gas 2 as electric power energy, and the thrust force acting on the drive shaft 4 can be substantially reduced. Since it can be lost, the thrust bearing 7 (see FIG. 3) can be removed or remarkably downsized, the labor for production can be remarkably reduced, and the production cost can be remarkably reduced.

Further, if the balance of the thrust forces generated in the high pressure expander 13 and the low pressure expander 14 is maintained, the high pressure expander 13 and the low pressure expander 14 can be increased in size without any particular limitation. Compared with the conventional single-stage expander 5 (see FIG. 3), the expansion degree of the high-pressure hydrogen gas 2 can be increased, and the high-pressure hydrogen gas 2 before expansion and the low-pressure hydrogen gas 2'after expansion The pressure ratio limitation can be significantly eased.

Further, the temperature of the hydrogen gas 2 expanded by the high-pressure expander 13 and lowered in temperature is raised by heat exchange with the heat exchange medium 12 while passing through the re-cooling type refrigerating cooler 16 by the connecting pipe 17. Therefore, even if the hydrogen gas 2 expanded by the high-pressure expander 13 is used, the low-pressure expander 14 can be rotatably driven well and a sufficient output (electric power energy by the generator) can be obtained.
The low-pressure hydrogen gas 2'expanded by the low-pressure expander 14 and lowered in temperature can be heated by heat exchange with the heat-exchange medium 12 while the exhaust pipe 18 re-passes through the recooling type refrigerating cooler 16. Therefore, by supplying it to the combustion equipment on the downstream side, it can be favorably used as fuel or the like without a temperature problem.

On the other hand, in the recooling type refrigerating cooler 16, the hydrogen gas 2 immediately after expansion from the high pressure expander 13
And since the heat exchange medium 12 can be heat-exchanged twice with the low pressure hydrogen gas 2 ′ immediately after expansion from the low pressure expander 14, a cryogenic cooling medium 12 ′ can be obtained. It can be effectively used by supplying it to equipment with a demand for cryogenic heat.

The high-pressure hydrogen gas energy recovery apparatus of the present invention is not limited to the above-described embodiment, and in FIG. 1, a double flow is adapted to perform gas expansion from the axial middle portion to both sides. I've shown the expander,
It is also possible to use a double flow expander that expands gas from both sides in the axial direction toward the middle part, and in FIG. 2, the directions in which the high pressure expander and the low pressure expander perform gas expansion are separated from each other. Although shown for the sake of illustration, the directions of gas expansion of the high-pressure expander and the low-pressure expander may be opposite to each other in the opposite direction to each other, and in addition, variously within a range not departing from the gist of the present invention. Of course, changes can be made.

[0036]

According to the energy recovery system for high-pressure hydrogen gas of the present invention described above, various excellent effects as described below can be obtained.

(I) The high-pressure hydrogen gas can be decompressed to a desired pressure while effectively recovering the pressure energy of the high-pressure hydrogen gas as electric power energy, and the thrust force acting on the drive shaft can be almost lost. Therefore, the thrust bearing can be removed or the size can be remarkably reduced, the labor for manufacturing can be remarkably reduced, and the manufacturing cost can be remarkably reduced.

(II) The expansion degree of the high-pressure hydrogen gas can be increased as compared with the conventional single-stage expander, and the pressure ratio between the high-pressure hydrogen gas before expansion and the low-pressure hydrogen gas after expansion is limited. Can be significantly eased.

(III) Since the low-pressure hydrogen gas that has been expanded and decreased in temperature can be heated by heat exchange with the heat exchange medium while passing through the refrigerating cooler through the discharge pipe, combustion equipment on the downstream side, etc. Can be used favorably as a fuel or the like without causing a temperature problem.

(IV) The heat exchange medium, which has been heat-exchanged with the low-pressure hydrogen gas immediately after expansion in the refrigerating cooler, can be effectively used by supplying it as a low-temperature cooling medium to equipment having low-temperature heat demand. .

(V) In particular, according to the invention described in claim 2, the hydrogen gas expanded by the high-pressure expander and lowered in temperature is used as a heat exchange medium while passing through the re-cooling type refrigerating cooler through the connecting pipe. Since the temperature can be raised by the heat exchange of the low pressure expander, the low pressure expander can be rotatably driven well and sufficient output (electric power energy from the generator) can be obtained even if hydrogen gas expanded by the high pressure expander is used. .

(VI) Particularly, according to the invention described in claim 2, hydrogen gas immediately after expansion from the high-pressure expander and low-pressure hydrogen gas immediately after expansion from the low-pressure expander in the recooling type refrigerating cooler. On the other hand, since the heat exchange medium can be heat-exchanged twice, a cryogenic cooling medium can be obtained, and it can be effectively used by supplying it to equipment with cryogenic heat demand. You can

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of the invention described in claim 1 of the present invention.

FIG. 2 is a schematic view showing an embodiment of the invention described in claim 2 of the present invention.

FIG. 3 is a schematic view showing a conventional example.

[Explanation of symbols]

 2 high-pressure hydrogen gas 2'low-pressure hydrogen gas 3 generator 4 drive shaft 8 double-flow expander 8a inlet 8b outlet 9 introduction pipe 10 refrigerating cooler 11 discharge pipe 12 heat exchange medium 13 high-pressure expander 13a inlet 13b outlet 14 low-pressure expander 14a Inlet 14b Outlet 15 Introducing pipe 16 Recooling type refrigerating cooler 17 Connecting pipe 18 Discharging pipe

Claims (2)

[Claims] 1. A double flow expander is provided on a drive shaft connected to a generator, the gas expands from an axially intermediate portion toward both sides or from both axial directions toward an intermediate portion, and an inlet of the double flow expander. A high-pressure hydrogen gas is connected to an inlet pipe, and a discharge pipe for discharging low-pressure hydrogen gas via a refrigerating cooler for cooling the heat exchange medium is connected to the outlet of the double flow expander. High-pressure hydrogen gas energy recovery device. 2. A high-pressure expander and a low-pressure expander, which perform gas expansion in opposite directions, are provided on a drive shaft connected to a generator, and an introduction pipe for introducing high-pressure hydrogen gas to the inlet of the high-pressure expander is provided. Connected, the outlet of the high-pressure expander and the inlet of the low-pressure expander are connected via a connecting pipe passing through a recooling type refrigeration cooler for cooling the heat exchange medium, and the outlet of the low-pressure expander An energy recovery device for high-pressure hydrogen gas, characterized in that a discharge pipe for discharging low-pressure hydrogen gas is connected via a recooling type refrigeration cooler.