JP3616761B2 - Refrigerator operation method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a refrigerator operating method.
[0002]
[Prior art]
Generally, in a regenerative refrigerator, high-pressure and low-pressure gas is taken in and out of the refrigerator at a predetermined timing to compress, expand, and move the gas in the refrigerator to generate cold. More specifically, the entropy is lowered by compressing the gas and removing the heat of compression, the entropy is raised by expanding and absorbing the gas, and the compression part and the expansion part are separated in temperature by using a regenerator. Like to do. Examples of the regenerative refrigerator using such a refrigeration cycle include a GM refrigerator and a pulse tube refrigerator.
[0003]
Normally, a regenerative refrigerator is connected to a compressor unit, the gas sucked by the compressor unit is compressed and discharged as a high-pressure gas, and then the high-pressure gas is sucked by the refrigerator and the gas is compressed in the refrigerator. After expanding and moving and discharging from the refrigerator as low-pressure gas, the low-pressure gas is again sucked by the compressor unit, thereby circulating the gas. In addition, this gas is distinguished from atmospheric gas and is called working gas.
[0004]
The reason why the working gas is circulated in this way is to separate the working gas from the air or the atmospheric gas so that the working gas is not mixed with the air or the atmospheric gas. This is because it is convenient to continuously generate cold.
[0005]
As a refrigeration apparatus using the above regenerative refrigerator, there is a refrigeration apparatus shown in FIG. This refrigeration apparatus uses a pulse tube refrigerator 1 as a regenerative refrigerator and is connected to a compressor unit 2. The pulse tube refrigerator 1 includes a high-pressure gas valve 3, a low-pressure gas valve 4, a regenerator 5, a cold end portion 6, a pulse tube 7, and a phase control unit 8. An active buffer type phase control unit 8 including on-off valves 9 and 10 and buffer tanks 11 and 12 is used. The compressor unit 2 includes a compressor 13. The discharge port 13 a of the compressor 13 is connected to the suction port 1 a of the pulse tube refrigerator 1 through the high-pressure gas line 14, and the suction port 13 b of the compressor 13. Is connected to the discharge port 1b of the pulse tube refrigerator 1 through the low-pressure gas line 15.
[0006]
The high-pressure gas boosted by the compressor 13 is sent to the pulse tube refrigerator 1 through the high-pressure gas line 14, and the low-pressure gas discharged from the pulse tube refrigerator 1 is returned to the compressor 13 through the low-pressure gas line 15. The high-pressure gas valve 3 and the low-pressure gas valve 4 are opened and closed at a predetermined timing, and the opening and closing valves 9 and 10 of the phase control unit 8 are opened and closed in conjunction with the opening and closing, so that the gas in the pulse tube 7 is changed. Compression, expansion, and movement occur, and cold is generated at the cold end 6.
[0007]
In such a refrigeration apparatus, power is required for the compressor 13 to boost the low pressure gas to the high pressure gas. Usually, electric power is used as power that can be obtained continuously and stably, and thereby, cold can be generated continuously.
[0008]
[Problems to be solved by the invention]
However, when the pressure of the low pressure gas is increased to the high pressure gas using the compressor 13, generally, the input power is required to be about 30 to 40 times the refrigerating capacity. For example, if the refrigerating capacity is 1 kW, about 30 to 40 kW of electric power is required, but the current situation is that such a regenerative refrigerator is not enlarged. Therefore, if the high-pressure gas source can be connected to the regenerative refrigerator without using the compressor 13, the input power becomes unnecessary, and thus a refrigerator having a large refrigerating capacity can be obtained without a compressor that requires input power. Since it can be realized, its realization is strongly desired.
[0009]
The present invention has been made in view of such circumstances, and an object thereof is to provide a refrigerator operating method that does not require a compressor unit.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, the refrigerator operating method of the present invention includes a regenerative refrigerator placed in a non-circulating gas fluid flow, and the pressure of the gas fluid downstream of the regenerator refrigerator is set. The pressure is at least 0.1 MPa lower than the pressure of the gas fluid on the upstream side, and the cold storage is generated by operating the regenerative refrigerator with this pressure difference.
[0011]
That is, in the refrigerator operating method of the present invention, the pressure of the gas fluid on the downstream side of the regenerative refrigerator disposed in the flow of the non-circulating gas fluid is at least 0.1 MPa higher than the pressure of the gas fluid on the upstream side. A low pressure is set, and a cold storage is generated by operating the regenerative refrigerator with this pressure difference. Thus, in this invention, since the cold storage type refrigerator is operated using the pressure difference of the gas fluid, a compressor unit is unnecessary. Further, as long as the gas fluid flow is continuously formed, it is possible to continuously generate cold.
[0012]
Next, the present invention will be described in detail.
[0013]
The gaseous fluid of the present invention, natural gas, nitrogen, oxygen, air, hydrogen, carbon dioxide, argon, ethylene, propane, butane, methane, but any one of ethane are used, two or more of these A mixed gas may be used. Further, the pressure of the gas fluid on the downstream side of the regenerative refrigerator needs to be at least 0.1 MPa or more lower than the pressure of the gas fluid on the upstream side, but preferably 0.5 MPa or more.
[0014]
The supply of natural gas is usually supplied from the supply source to the demand destination under high pressure, medium pressure, and low pressure conditions in three stages. This is because in the case of long-distance supply, the diameter of the high-pressure supply conduit is made as small as possible for economic reasons. That is, since the main supply line has a large amount of gas to be sent, it carries a large amount of gas at a high pressure. And as it approaches the customer, it is branched from the main supply line, and the pressure is reduced using a pressure reducing valve in each branch supply line. For this reason, there are several stages of pressure lines (for example, a three-stage pressure line including a high-pressure line, a medium-pressure line, and a low-pressure line) in the supply line.
[0015]
Therefore, instead of the pressure reducing valve or in parallel with the pressure reducing valve, a regenerator type refrigerator is provided, the high pressure side supply line is connected to the inlet of the regenerator type refrigerator, and the low pressure side supply line having a lower pressure is refrigerated. When connected to the discharge port of the refrigerating type refrigerator, high pressure and low pressure gas can be connected to the regenerative refrigerating machine in the same way as the regenerative refrigerating machine is connected to the compressor unit. Generates cold. As described above, when the supply line is used, no new power is required to obtain the high-pressure gas and the low-pressure gas in driving the regenerator. In addition, the compressor unit becomes unnecessary and the power can be reduced. In addition, the compressor unit requires maintenance work in the case of long-term operation, but it is not necessary to do this, and cost reduction can be expected.
[0016]
Further, when the present invention is not adopted in the natural gas supply line (when the pressure is reduced using only the pressure reducing valve), the temperature of the natural gas is reduced by free expansion of the natural gas in the pressure reducing valve and the low pressure side supply line. The side supply line may freeze, possibly causing damage. Therefore, the device which raises gas temperature is needed and it heats using a heater as a simple method. On the other hand, when the present invention is adopted, the temperature of the natural gas discharged from the regenerative refrigerator is not reduced, so there is no need for heating with a heater in the low-pressure side supply line, reducing heater power and cost. Reduction and failure can be reduced.
[0017]
Examples of the regenerative refrigerator of the present invention include a GM refrigerator and a pulse tube refrigerator. There are various types of pulse tube refrigerators depending on the phase control mechanism, for example, an active buffer type, a double inlet type, an orifice type, etc., which are a combination of a plurality of valves and a buffer tank, and any phase control mechanism may be used. Moreover, the pulse tube refrigerator (it is called a basic type pulse tube refrigerator) which does not have a phase control mechanism may be sufficient.
[0018]
The regenerative refrigerator of the present invention can be used for gas liquefaction and generation of cooling gas by exchanging the cold generated at the cold end. It can also be used as a cold source for a freezer. In addition, the sensor can be cooled directly or indirectly for the purpose of reducing noise and increasing sensitivity. It is also possible to cool the superconductor directly or indirectly.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
[0020]
FIG. 1 shows an embodiment of a refrigeration apparatus using the refrigerator operating method of the present invention. In the figure, reference numeral 20 denotes a natural gas supply pipeline (supply line) formed in a non-circulation system. The supply pipeline 20 is provided with a pulse tube refrigerator 1 instead of a pressure reducing valve. In this embodiment, the same structure as the pulse tube refrigerator 1 shown in FIG. 5 is used as the pulse tube refrigerator 1. 21 is a high-pressure gas pipeline connected to the suction port 1a of the pulse tube refrigerator 1 (that is, a pipeline upstream of the pulse tube refrigerator 1 of the supply pipeline 20), and 22 is a pulse tube refrigerator 1 Is a low-pressure gas pipeline connected to the discharge port 1b (that is, a pipeline downstream of the pulse tube refrigerator 1 of the supply pipeline 20). The pressure of the natural gas flowing through the high-pressure gas pipeline 21 is set to 3 MPa, and the pressure of the natural gas flowing through the low-pressure gas pipeline 22 is set to 0.5 MPa.
[0021]
In the above configuration, when 10000 Nm ³ / h natural gas is supplied to the supply pipeline 20, the natural gas flowing through the high-pressure gas pipeline 21 flows into the pulse tube refrigerator 1 from the inlet 1 a of the pulse tube refrigerator 1, The pulse tube refrigerator 1 is operated. Thereby, cold is generated on the same principle as the pulse tube refrigerator 1 shown in FIG. 5, and this cold can be taken out from the cold end portion 6. The cold energy that can be taken out at this time is about 16 kW at a temperature of 165K. Then, the low-pressure natural gas is discharged from the discharge port 1b of the pulse tube refrigerator 1 to the low-pressure gas pipeline 22 and supplied to the customer.
[0022]
As described above, in this embodiment, the compressor unit can be omitted, and the power and cost can be reduced. Moreover, the cold obtained by the pulse tube refrigerator 1 can be used for gas liquefaction or the like.
[0023]
FIG. 2 shows another embodiment of the refrigeration apparatus using the refrigerator operating method of the present invention. In this embodiment, a shunt gas pipeline 23 for connecting the high pressure gas pipeline 21 and the low pressure gas pipeline 22 in the above embodiment is provided, and a pressure reducing valve 24 having a heater 25 is provided in the shunt gas pipeline 23. doing. Other parts are the same as those in the above embodiment, and the same reference numerals are given to the same parts.
[0024]
In the above configuration, a part of the natural gas flowing through the high-pressure gas pipeline 21 flows into the pulse tube refrigerator 1 from the suction port 1a of the pulse tube refrigerator 1, and the pulse tube refrigerator 1 is placed in the same manner as in the above embodiment. Let it run. On the other hand, the other part of the natural gas flowing through the high-pressure gas pipeline 21 is diverted to the diversion gas pipeline 23, and after being depressurized by the pressure reducing valve 24, it is heated by the heater 25 and flows into the low-pressure gas pipeline 22.
[0025]
The pressure of the natural gas high-pressure gas pipelines 21 3 MPa, at a pressure 0.5MPa of the low-pressure gas pipeline 22, the flow rate of natural gas pulse tube refrigerator 1 side 10000 Nm ³ / h, in the case of the pressure reducing valve 24 side 10000 Nm ³ / h, The cold energy generated in the pulse tube refrigerator 1 is about 16 kW, and a heater of about 35 kW is required on the pressure reducing valve 24 side.
[0026]
As described above, even in this embodiment, the compressor unit can be omitted, and the power and cost can be reduced. Moreover, the cold obtained by the pulse tube refrigerator 1 can be used for gas liquefaction or the like. Moreover, the amount of cold generated in the pulse tube refrigerator 1 can be controlled by controlling the amount of natural gas flowing through the pulse tube refrigerator 1 and the pressure reducing valve 24.
[0027]
FIG. 3 shows still another embodiment of the refrigeration apparatus using the refrigerator operating method of the present invention. In this embodiment, in the embodiment shown in FIG. 1, the natural gas diverted from the high-pressure gas pipeline 21 is liquefied and stored using the cold generated in the pulse tube refrigerator 1. In the figure, 31 is a storage tank for storing liquefied natural gas. Reference numeral 32 denotes a first connecting pipe that connects the high-pressure gas pipeline 21 of the supply pipeline 20 and the lateral wall of the storage tank 31. Reference numeral 33 denotes a low-pressure gas pipeline 22 of the supply pipeline 20 and the ceiling wall of the storage tank 31. It is the 2nd connection pipe which connects. Reference numeral 34 denotes a first heat exchanger provided at a portion of the first connection pipe 32 corresponding to the cold end portion 6 of the pulse tube refrigerator 1. Reference numeral 35 denotes a second heat exchanger provided in a portion of the first connection pipe 32 between the first heat exchanger 34 and the high-pressure gas pipeline 21. The second heat exchanger 35 is disposed in the middle of the second connection pipe 33. Yes. Reference numeral 36 denotes a flow rate adjusting valve provided in a portion of the first connecting pipe 32 between the first heat exchanger 34 and the storage tank 31. Reference numeral 37 denotes a take-out pipe with a flow control valve 38 extending from the bottom wall of the storage tank 31. Other parts are the same as those of the embodiment shown in FIG. 1, and the same reference numerals are given to the same parts.
[0028]
In the above configuration, part of the natural gas flowing through the high-pressure gas pipeline 21 flows into the pulse tube refrigerator 1 from the suction port 1a of the pulse tube refrigerator 1, and the pulse tube is similar to the embodiment shown in FIG. The refrigerator 1 is operated. On the other hand, the other part of the natural gas flowing through the high-pressure gas pipeline 21 is diverted to the first connection pipe 32 and passes through the second heat exchanger 35, while evaporating gas and heat of the liquefied natural gas flowing through the second connection pipe 33. Then, while passing through the first heat exchanger 34, the heat is exchanged at the cold end 6 of the pulse tube refrigerator 1 and liquefied, and then stored in the storage tank 31. The liquefied natural gas stored in the storage tank 31 is taken out via the take-out pipe 37 and used as necessary. Further, the evaporative gas of the liquefied natural gas accumulated in the upper portion of the storage tank 31 is heated by exchanging heat with the natural gas flowing through the first connection pipe 32 while passing through the second heat exchanger 35, and then the low-pressure gas pipe. Sent to line 22.
[0029]
As described above, this embodiment has the same operations and effects as the embodiment shown in FIG. Moreover, the liquefied natural gas can be stored in the storage tank 31 using the coldness of the cold end portion 6 of the pulse tube refrigerator 1.
[0030]
FIG. 4 shows still another embodiment of a refrigeration apparatus using the refrigerator operating method of the present invention. In this embodiment, in the embodiment shown in FIG. 3, a portion of the high pressure gas pipeline 21 upstream of the first connection pipe 32 and a portion of the low pressure gas pipeline 22 downstream of the second connection pipe 33 are combined. A shunt gas pipeline 39 to be connected is provided, and a pressure reducing valve 40 having a heater 41 is disposed in the shunt gas pipeline 39. Other parts are the same as those in the embodiment shown in FIG. 3, and the same reference numerals are given to the same parts.
[0031]
In the above configuration, part of the natural gas flowing through the high-pressure gas pipeline 21 flows into the pulse tube refrigerator 1 from the suction port 1a of the pulse tube refrigerator 1, and the pulse tube refrigeration is performed as in the embodiment shown in FIG. The machine 1 is operated. On the other hand, the other part of the natural gas flowing through the high-pressure gas pipeline 21 is diverted to the diversion gas pipeline 39, and after being depressurized by the pressure reducing valve 40, it is heated by the heater 41 and flows into the low-pressure gas pipeline 22. Further, the remaining portion of the natural gas flowing through the high-pressure gas pipeline 21 is diverted to the first connection pipe 32, and the same operation as in the embodiment shown in FIG. 3 is performed.
[0032]
As described above, this embodiment has the same operations and effects as those of the embodiment shown in FIG. Moreover, the amount of cold generated in the pulse tube refrigerator 1 can be controlled by controlling the amount of natural gas flowing through the pulse tube refrigerator 1 and the pressure reducing valve 40.
[0033]
In each of the above embodiments, natural gas is used as the gas fluid. However, the present invention is not limited to this, and a gas fluid such as nitrogen, oxygen, or air may be used. Further, a GM refrigerator or the like may be used instead of the pulse tube refrigerator.
[0034]
【The invention's effect】
As described above, in the refrigerator operating method of the present invention, the pressure of the gas fluid on the downstream side of the regenerative refrigerator disposed in the flow of the non-circulating gas fluid is at least 0 from the pressure of the gas fluid on the upstream side. The pressure is reduced to 1 MPa or more, and the regenerative refrigerator is operated with this pressure difference to generate cold. Thus, in this invention, since the cold storage type refrigerator is operated using the pressure difference of the gas fluid, a compressor unit is unnecessary. Further, as long as the gas fluid flow is continuously formed, it is possible to continuously generate cold.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing an embodiment of a refrigeration apparatus using a refrigerator operating method of the present invention.
FIG. 2 is an explanatory view showing another embodiment of a refrigeration apparatus using the refrigerator operating method of the present invention.
FIG. 3 is an explanatory view showing still another embodiment of a refrigeration apparatus using the refrigerator operating method of the present invention.
FIG. 4 is an explanatory view showing still another embodiment of the refrigeration apparatus using the refrigerator operating method of the present invention.
FIG. 5 is an explanatory diagram showing a conventional example.
[Explanation of symbols]
1 Pulse tube refrigerator

Claims (4)

A regenerative refrigerator is disposed in the flow of the non-circulating gas fluid, and the pressure of the gas fluid on the downstream side of the cool storage refrigerator is set to be at least 0.1 MPa lower than the pressure of the gas fluid on the upstream side. A method for operating a refrigerator, wherein a cold storage is generated by operating a regenerative refrigerator with a pressure difference. 2. The refrigerator according to claim 1, wherein the gas fluid is one or more of natural gas, nitrogen, oxygen, air, hydrogen, carbon dioxide, argon, ethylene, propane, butane, methane, and ethane. how to drive. The refrigerator operating method according to claim 1 or 2, wherein the cold storage type refrigerator is a GM refrigerator or a pulse tube refrigerator. The gas fluid is natural gas, and the flow of the non-circulating gas fluid is a supply line that supplies natural gas from a high pressure line to an intermediate pressure line, or from an intermediate pressure line to a low pressure line, or from a high pressure line to a low pressure line. The refrigerator operating method as described in any one of Claims 1-3.

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