JP2003056927A - Pulse pipe refrigerating machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pulse pipe refrigerating machine capable of keeping refrigeration capacity good even if environmental temperature rises. SOLUTION: The pulse pipe refrigerating machine comprises a compressor 1, a cold storage device 2, a pulse pipe 3 and a buffer 4 which are connected with each other in series, and is further provided with a cooling head 5 connecting the low temperature end 2a of the cold storage device and the low temperature end 3a of the pulse pipe. A fan 7 for coaling the buffer 4 and a power source 8 for supplying power to the fan 7 are also provided. When the refrigerating machine is activated, the fan 7 is supplied with the power from the power source 8 and sends wind to the buffer 4 as shown by the arrow A to cool the buffer 4. The temperature of the buffer 4 is prevented from being raised by heat emitted from the heated compressor 1 or the like so that refrigeration capacity is prevented from being lowered.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a pulse tube refrigerator.

[0002]

2. Description of the Related Art Conventionally, a pulse tube refrigerator has a compressor, a regenerator, a pulse tube, and a buffer connected in series, and changes the pressure of He (helium) gas generated by the compressor to the cold storage. To the reactor, the pulse tube and the buffer, and the phase of the pressure fluctuation of the He gas is changed by this buffer to generate cold heat at the low temperature end of the pulse tube. This cold heat is stored in the regenerator, and cold is obtained in the cooling head that connects the low temperature end of the regenerator and the low temperature end of the pulse tube.

The pulse tube refrigerator is equipped with a fan for cooling the compressor. When the environmental temperature of the place where the pulse tube refrigerator is arranged rises, the fan cools the compressor to cool the compressor. The temperature rises to prevent the pulse tube refrigerator from lowering the refrigerating capacity.

[0004]

However, the above-mentioned conventional pulse tube refrigerator has a problem that the refrigerating capacity is still lowered when the environmental temperature rises and the compressor is cooled to a predetermined temperature. .

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a pulse tube refrigerator which can maintain a good refrigerating capacity even when the environmental temperature rises.

[0006]

The inventor has found that the refrigerating capacity of the pulse tube refrigerator is correlated with the temperature of the buffer, and based on this finding, the present invention has been made.

FIG. 5 is a diagram showing changes in the refrigerating capacity of the pulse tube refrigerator with respect to changes in the temperature of the buffer of the pulse tube refrigerator. The horizontal axis is the temperature of the buffer, and the unit is Celsius. The vertical axis represents the refrigerating capacity of the pulse tube refrigerator, and the unit is W (watt). The refrigerating capacity of this pulse tube refrigerator is such that the pulse tube refrigerator is operated and the heater provided in the cooling head is caused to generate heat, so that the cooling head is kept at 77K.
It was detected by measuring the electric power supplied to the heater in order to keep (Kelvin). Here, the refrigerating capacity of the pulse tube refrigerator was detected without changing the conditions other than the buffer temperature, for example, the conditions such as the compressor temperature.

As can be seen from the curve 51 in FIG. 5, when the temperature of the buffer is room temperature of about 25 ° C., the refrigerating capacity of the pulse tube refrigerator is about 3.0 W. When the temperature of the buffer rises from about 25 ° C to about 60 ° C, the refrigerating capacity of the pulse tube refrigerator decreases to about 2.5W. On the other hand, when the temperature of the buffer drops from about 25 ° C. to about 5 ° C., the refrigerating capacity of the pulse tube refrigerator increases from about 3.0 W to about 3.3 W. When the temperature of the buffer is between about 60 ° C. and about 5 ° C., the refrigerating capacity of the pulse tube refrigerator improves at a predetermined rate as the temperature of the buffer decreases. When the temperature of the buffer is about 5 ° C. or lower, the rate of improvement of the refrigerating capacity of the pulse tube refrigerator with respect to the decrease of the temperature of the buffer is smaller than when the temperature of the buffer is 5 ° C. or higher. Therefore, especially when the temperature of the buffer is between 5 ° C and 60 ° C,
It can be said that the refrigeration capacity of the pulse tube refrigerator can be effectively improved by cooling the buffer.

The pulse tube refrigerator according to the invention of claim 1 is a pulse tube refrigerator in which a compressor, a regenerator, a pulse tube and a buffer are connected in series, and a cooling means for cooling the buffer is provided. It is characterized by that.

According to the pulse tube refrigerator of the first aspect, the buffer is cooled by the cooling means when the temperature rises due to, for example, an increase in environmental temperature. Therefore, the reduction of the refrigerating capacity of the pulse tube refrigerator due to the temperature rise of the buffer is effectively prevented.

A pulse tube refrigerator according to a second aspect of the present invention is the pulse tube refrigerator according to the first aspect, further comprising control means for controlling the cooling means to bring the buffer to a predetermined temperature. It has a feature.

According to the pulse tube refrigerator of the second aspect, when the temperature of the buffer rises, the temperature of the buffer becomes a predetermined temperature by the cooling means controlled by the control means. Therefore, the pulse tube refrigerator has a stable refrigerating capacity maintained at a predetermined capacity value.

A pulse tube refrigerator according to a third aspect of the invention is the pulse tube refrigerator according to the first or second aspect, wherein the cooling means includes a fan.

According to the pulse tube refrigerator of the third aspect, the fan effectively cools the buffer.

A pulse tube refrigerator according to a fourth aspect of the present invention is the pulse tube refrigerator according to any one of the first to third aspects, wherein the cooling means includes a Peltier element.

According to the pulse tube refrigerator of claim 4, the buffer is effectively cooled by the Peltier element, and the temperature of the buffer is adjusted by adjusting the power supplied to the Peltier element. Can be below the ambient temperature in which this buffer is located.

A pulse tube refrigerator according to a fifth aspect of the present invention is the pulse tube refrigerator according to any one of the first to fourth aspects, wherein the cooling means includes a heat pipe.

According to the pulse tube refrigerator of the fifth aspect, the buffer is effectively cooled by the heat pipe.

A pulse tube refrigerator according to a sixth aspect of the present invention is the pulse tube refrigerator according to any one of the first to fifth aspects, wherein the cooling means includes a radiation fin.

According to the pulse tube refrigerator of the sixth aspect, the buffer is effectively cooled by the heat radiation fins.

A pulse tube refrigerator according to a seventh aspect of the present invention is the pulse tube refrigerator according to any one of the second to sixth aspects, further comprising a temperature sensor for detecting the temperature of the buffer, and the control means. , Based on the output of the above temperature sensor,
It is characterized by controlling the cooling means.

According to the pulse tube refrigerator of claim 7, based on the output of the temperature sensor for detecting the temperature of the buffer,
Since the cooling means is controlled by the control means, the buffer is reliably brought to a predetermined temperature.

The pulse tube refrigerator according to the invention of claim 8 is the pulse tube refrigerator according to any one of claims 2 to 6, wherein the temperature of the cooling head connected to the low temperature end of the pulse tube is detected. It is characterized in that the control means controls the cooling means based on the output of the temperature sensor.

According to the pulse tube refrigerator of the eighth aspect, the cooling means is controlled by the control means based on the output of the temperature sensor for detecting the temperature of the cooling head.
The cooling means cools the buffer in accordance with the temperature of the cooling head, so that the cooling head has a predetermined temperature.

A pulse tube refrigerator according to a ninth aspect of the present invention is the pulse tube refrigerator according to any one of the third to eighth aspects, wherein the buffer and the compressor are arranged downstream of the fan. It is characterized in that both the buffer and the compressor are cooled.

According to the ninth aspect of the pulse tube refrigerator, since both the buffer and the compressor arranged downstream of the fan are cooled by the fan, the refrigerating capacity of the pulse tube refrigerator is lowered. Is reliably and efficiently prevented.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to the embodiments shown in the drawings.

FIG. 1A is a diagram showing an embodiment of the pulse tube refrigerator of the present invention. This pulse tube refrigerator has a compressor 1, a regenerator 2, a pulse tube 3 and a buffer 4 connected in series, and connects the low temperature end 2a of the regenerator and the low temperature end 3a of the pulse tube. A cooling head 5 to be connected is provided.
This pulse tube refrigerator is provided with a fan 7 as a cooling means for cooling the buffer 4, and the fan 7 has a power source 8
It is connected to the.

When the pulse tube refrigerator having the above structure is operated,
The compressor 1 generates pressure fluctuations in He gas. The He gas sent from the compressor 1 to the regenerator 2 is cooled by the regenerator 2 and is cooled from the low temperature end 2a to the low temperature end 3a of the pulse tube.
Sent to. The He gas guided to the pulse tube 3 is sent to the buffer 4, and the buffer 4 gives a phase difference to the flow and the pressure of the He gas. As a result, the He gas is adiabatically expanded at the low temperature end 3a of the pulse tube to generate cold heat, and the cold heat further lowers the low temperature end 2a of the regenerator. By repeating this action, 70
Cryogenic temperatures on the order of K are produced.

When the pulse tube refrigerator operates, the compressor 1 generates heat from the motor provided in the compressor 1 and He.
It becomes hot due to the heat of compression of the gas and releases heat. On the other hand, the fan 7 is supplied with electric power from the power source 8 and sends air to the buffer 4 as indicated by an arrow A to cool the buffer 4. Therefore, the temperature of the buffer 4 does not rise due to the heat released by the compressor 1 and the like. As a result, the pulse tube refrigerator according to the present embodiment can prevent the temperature of the buffer 4 from rising and prevent the refrigerating capacity from decreasing even when operating for a long time.

FIG. 1B is a diagram showing a buffer 4 provided with a cooling means of another embodiment. This buffer 4
Is connected to the same compressor, regenerator, and pulse tube as in FIG. The buffer 4 is provided with a Peltier element 11 as a cooling means, and the Peltier element 11 is supplied with electric power from a power source 12. The pulse tube refrigerator provided with the Peltier element 11 operates, and the Peltier element 11 is supplied with electric power from the power source 12. The electric power from the power source 12 is set so that the Peltier element 11 has a predetermined temperature. Therefore, the buffer 4 is provided with the Peltier element 11 even if the environmental temperature is relatively high.
It can be cooled to a predetermined temperature lower than the ambient temperature. Therefore, the pulse tube refrigerator of the present embodiment can obtain a stable and good refrigerating capacity than the pulse tube refrigerator including the fan shown in FIG.

FIGS. 2 (a) and 2 (b) are views showing a buffer 4 provided with a cooling means of another embodiment. Figure 2
Both the buffers 4 in (a) and (b) are connected to the same compressor, regenerator, and pulse tube as in FIG. 1 (a).

The buffer 4 shown in FIG. 2A is provided with a heat pipe 14 as a cooling means. The heat pipe 14 has a heat receiving portion 1 that receives heat from the buffer 4.
5 and the heat transfer section 1 for transmitting the heat received by the heat receiving section 15.
6 and a heat radiating section 17 that radiates the heat transferred by the heat transfer section 16.

When the pulse tube refrigerator provided with the heat pipe 14 is operated, the heat of the compressor 1 and the like is received and the temperature of the buffer 4 rises. Then, in the heat receiving portion 15 of the heat pipe 14, the heat of the buffer 4 is absorbed to evaporate the working fluid inside the heat pipe 14, and the evaporated working fluid reaches the heat radiating portion 16 via the heat transfer portion 16. The working fluid is condensed in the heat radiating section 16 to generate heat of condensation. The heat of condensation is released to the outside, and the condensed working fluid returns to the heat receiving unit 15. By repeating this, the heat of the buffer 4 is released to the outside by the heat pipe 14 and the buffer 4 is cooled. The buffer 4 provided with the heat pipe 14 can be cooled with a simple structure without using electric power. Therefore, the pulse tube refrigerator provided with the heat pipe 14 can prevent the reduction of the refrigerating capacity at low cost.

The buffer 4 shown in FIG. 2B is provided with radiating fins 21 and 21 as cooling means on the outer surface thereof.
The radiation fins 21 and 21 can also cool the buffer 4 with a simple structure without using electric power. Therefore,
The pulse tube refrigerator provided with the heat pipe 14 can prevent the reduction of the refrigerating capacity at low cost.

The cooling means of the embodiment of FIG. 2 (a) may include a fan for blowing air to the heat radiating portion 16 of the heat pipe. By blowing air to the heat radiating unit 16 with this fan, the amount of heat radiated by the heat radiating unit 16 per time is increased, and thereby the amount of heat per unit of time removed by the heat receiving unit 15 from the buffer 4 is increased. 4 can be cooled quickly.

The cooling means of the embodiment shown in FIG. 2 (b) may include a fan for blowing air to the heat radiation fins 21 and 21. By blowing air to the radiation fins 21 and 21 with this fan, the amount of heat radiation of the radiation fins 21 and 21 per hour is increased, and the buffer 4 can be cooled quickly.

FIG. 3A shows a pulse tube refrigerator according to another embodiment. This pulse tube refrigerator is shown in FIG.
The pulse tube refrigerator of (a) is provided with a temperature sensor 31 for detecting the temperature of the buffer 4, and is provided with a controller 33 as control means for controlling the air volume of the fan 7 instead of the power source of the fan 7. Become. The same parts as those of the pulse tube refrigerator in FIG. 1A are designated by the same reference numerals, and detailed description thereof will be omitted. The controller 33 is electrically connected to a temperature sensor 31 that detects the temperature of the buffer 4, changes the power supplied to the fan 7 based on the output of the temperature sensor 31, and changes the rotation speed of the fan 7. Is controlled to adjust the air volume of the fan 7.

The pulse tube refrigerator operates to operate the compressor 1
When the temperature of the buffer 4 rises due to the heat received from the controller 7, the controller 33, which receives the output from the temperature sensor 31 that detects the temperature rise, changes the electric power supplied to the motor of the fan 7 to change the electric power of the fan 7. Increase the rotation speed.
As a result, the amount of the wind A received by the buffer 4 from the fan 7 increases, the amount of heat taken by the buffer 4 increases, and the temperature of the buffer 4 decreases. In this way
The temperature of the buffer 4 is detected by the temperature sensor 31,
Since the controller 33 reliably controls the temperature to the predetermined temperature, it is possible to stably prevent the cooling capacity of the pulse tube refrigerator from decreasing.

The pulse tube refrigerator shown in FIG.
It differs from the pulse tube refrigerator of (a) in that a temperature sensor 36 for detecting the temperature of the cooling head 5 is provided instead of the temperature sensor 31 for detecting the temperature of the buffer 4.
The controller 38 controls the rotation speed of the fan 7 based on the output of the temperature sensor 36 of the cooling head 5.

When the pulse tube refrigerator is operating, the refrigerating capacity of the pulse tube refrigerator may be lowered due to the temperature rise of the buffer 4 and the temperature of the cooling head 5 may rise. The temperature sensor 36 detects this temperature rise, and the controller 38 receiving the output from this temperature sensor 36
The rotation speed of the fan 7 is increased by changing the power supplied to the motor of the fan 7. As a result, the amount of the wind A received by the buffer 4 from the fan 7 is increased, the temperature of the buffer 4 is lowered, and the refrigerating capacity of the pulse tube refrigerator is improved. Therefore, this pulse tube refrigerator can stably maintain the temperature of the cooling head.

In the pulse tube refrigerator shown in FIGS. 3A and 3B, a Peltier element is provided in place of the fan 7, and electric power supplied to the Peltier element is controlled by controllers 33 and 38. May be. As a result, the temperature of the buffer 4 can be made lower than the ambient temperature, so that the refrigerating capacity of the pulse tube refrigerator can be greatly improved, and the temperature of the cooling head 5 can be quickly brought to a predetermined temperature.

FIG. 4 is a side view showing a pulse tube refrigerator according to another embodiment. In this pulse tube refrigerator, a substantially cylindrical compressor 1 and a cylindrical buffer 4 are arranged substantially in parallel,
The compressor 1 and the buffer 4 are arranged downstream of the air blow A by the fan 7. The buffer 4 is arranged closer to the fan 7 than the compressor 1, so that the heat of the compressor 1 is less likely to be received. By the fan 7,
Since the compressor 1 is cooled together with the buffer 4, the refrigerating capacity of the pulse tube refrigerator can be rapidly and significantly improved as compared with the case where only the buffer 4 of the pulse tube refrigerator is cooled.

In the above embodiment, in the pulse tube refrigerator, the compressor 1, the regenerator 2, the pulse tube 3 and the buffer 4 are connected in series. However, between the compressor 1 and the regenerator 2 and the pulse A bypass connecting the tube 3 and the buffer 4 may be provided.

[0045]

As is apparent from the above, according to the pulse tube refrigerator of the invention of claim 1, in the pulse tube refrigerator in which the compressor, the regenerator, the pulse tube and the buffer are connected in series. Since the cooling means for cooling the buffer is provided, the temperature rise of the buffer is prevented and the reduction of the refrigerating capacity of the pulse tube refrigerator is effectively prevented.

According to the pulse tube refrigerator of the invention of claim 2, since the control means for controlling the cooling means to bring the buffer to a predetermined temperature is provided, the buffer is brought to a predetermined temperature. The pulse tube refrigerator has a stable refrigerating capacity and can maintain a predetermined capacity value.

According to the pulse tube refrigerator of the third aspect of the invention, since the cooling means includes a fan, the buffer can be effectively cooled.

According to the pulse tube refrigerator of the fourth aspect of the present invention, since the cooling means includes the Peltier element, the buffer can be effectively cooled and the power supplied to the Peltier element is adjusted. By doing so, the temperature of the buffer can be stably lower than the environmental temperature in which the buffer is arranged.

According to the pulse tube refrigerator of the fifth aspect of the invention, since the cooling means includes a heat pipe, the buffer can be effectively cooled.

According to the pulse tube refrigerator of the sixth aspect of the present invention, since the cooling means includes the radiation fins, the buffer can be effectively cooled.

According to the pulse tube refrigerator of the invention of claim 7, a temperature sensor for detecting the temperature of the buffer is provided.
Since the control means controls the cooling means based on the output of the temperature sensor, it is possible to reliably bring the buffer to a predetermined temperature.

According to the eighth aspect of the pulse tube refrigerator, there is provided a temperature sensor for detecting the temperature of the cooling head connected to the low temperature end of the pulse tube, and the control means outputs the temperature sensor. Based on this, since the cooling means is controlled, the refrigerating capacity of the pulse tube refrigerator can be adjusted in accordance with the temperature of the cooling head, and the cooling head can be brought to a predetermined temperature.

According to the pulse tube refrigerator of the ninth aspect of the present invention, the buffer and the compressor are arranged on the downstream side of the fan to cool both the buffer and the compressor. The reduction of the refrigerating capacity of the pulse tube refrigerator can be reliably and efficiently prevented.

[Brief description of drawings]

FIG. 1 (a) is a view showing an embodiment of a pulse tube refrigerator of the present invention, and FIG. 1 (b) shows a buffer 4 provided with a cooling means of another embodiment. It is a figure.

FIG. 2A is a diagram showing a buffer 4 provided with a heat pipe 14 as a cooling unit, and FIG.
(B) is a radiation fin 21 as a cooling means on the outer surface,
It is a figure which shows the buffer 4 in which 21 was provided.

3 (a) is a diagram showing a pulse tube refrigerator including a temperature sensor 31 for detecting the temperature of the buffer 4 and a controller 33 for controlling the air volume of the fan 7. FIG.
(B) is a temperature sensor 3 for detecting the temperature of the cooling head 5.
6 is a diagram showing a pulse tube refrigerator provided with a controller 38 for controlling the air volume of the fan 6 and the fan 7. FIG.

FIG. 4 is a side view showing a pulse tube refrigerator according to another embodiment.

FIG. 5 is a diagram showing a change in refrigerating capacity of the pulse tube refrigerator with respect to a temperature change of a buffer of the pulse tube refrigerator.

[Explanation of symbols]

1 compressor 2 regenerator 2a Low temperature end of regenerator 3 pulse tube 3a Low temperature end of pulse tube 4 buffers 5 cooling head 7 fans 8 power supplies 11 Peltier element 12 power supplies

Claims (9)

[Claims] 1. A pulse tube refrigerator in which a compressor (1), a regenerator (2), a pulse tube (3) and a buffer (4) are connected in series to cool the buffer (4). Cooling means (7, 11, 1
4, 21), and a pulse tube refrigerator. 2. The pulse tube refrigerator according to claim 1, further comprising control means (33, 38) for controlling the cooling means (7, 11) to bring the buffer (4) to a predetermined temperature. A pulse tube refrigerator characterized by that. 3. The pulse tube refrigerator according to claim 1 or 2, wherein the cooling means includes a fan (7). 4. The pulse tube refrigerator according to claim 1, wherein the cooling unit includes a Peltier element (11). 5. The pulse tube refrigerator according to claim 1, wherein the cooling unit includes a heat pipe (14). 6. The pulse tube refrigerator according to claim 1, wherein the cooling means includes a heat radiation fin (21). 7. The pulse tube refrigerator according to claim 2, wherein the temperature sensor (3) detects the temperature of the buffer (4).
1), and the control means (33) controls the cooling means (7) based on the output of the temperature sensor (31). 8. The pulse tube refrigerator according to claim 2, wherein the temperature of the cooling head (5) connected to the low temperature end (3a) of the pulse tube (3) is detected. A pulse tube refrigerator comprising a temperature sensor (36), wherein the control means (38) controls the cooling means (7) based on the output of the temperature sensor (36). 9. The pulse tube refrigerator according to claim 3, wherein the buffer (4) and the compressor (1) are arranged downstream of the fan (7), A pulse tube refrigerator characterized in that both the buffer (4) and the compressor (1) are cooled.