JPH0460367A - Cooling apparatus - Google Patents

Abstract

PURPOSE:To extend the range in which the temperature of a cooled body can be set by a method wherein between the last stage of a refrigerant line for a refrigerant with the lowest boiling point and a cooled body, a plurality of secondary refrigerant circulating lines, each of which contains a secondary refrigerant differing in boiling point from another, are provided in parallel. CONSTITUTION:Mixed refrigerant gas discharged by the compressor 101 undergoes repetitive gas-liquid separation; after undergoing condensation at a heat exchanger 113, a gaseous phase refrigerant with the lowest boiling point undergoes expansion under reduced pressure at a capillary tube 115, hence assuming two phases of gas and liquid, and then at a cooling device 140 becomes vaporized in part by absorption of heat from the secondary refrigerant in a brine line 141, and at a cooling device 150 it absorbs heat from the secondary refrigerant in a brine line 151; after passing through the heat exchangers successively the refrigerant returns to the compressor in the form of low pressure gas at normal temperature. The secondary refrigerant used in each of the brine lines 141, 151 differs in boiling point from the secondary refrigerant in the other brine line. Therefore there is a difference in temperature between the cooling coils 143, 153. And by adjusting the openings of flow-regulating valves V1, V2, changes of the temperature of a cooled body 123 based on the tempera ture difference can be effected in a wide range.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an indirect cooling type multistage cooling device.

(Prior art) Conventionally, as an ultra-low temperature cooling device for obtaining an ultra-low temperature of -100°C or less, a refrigeration cycle equipped with multiple stages of gas-liquid separators and heat exchangers cools a secondary refrigerant, and There is an indirect cooling multi-stage cooling device that uses a refrigerant to cool an object to be cooled.

FIG. 9 is a circuit diagram showing a conventional indirect cooling type multi-stage cooling device. As shown in the figure, this cooling device includes a compressor 1, a condenser 2, first to fourth gas-liquid separators 3, 69.12, and first to fourth Heat exchanger 4, 7. ]0.13, and the first constituting the expansion means.
to fifth capillary tube 5, 8, 11.14.
15 and a cooler 16 are provided. Furthermore, cooler 1
6 and the object to be cooled 23, three secondary refrigerant circulation paths such as a brine circuit 31 having a cooling coil 31 are provided.

In this cooling device, a plurality of mixed refrigerants having different boiling points are sealed. The mixed refrigerant that has passed through the compressor 1 and condenser 2 is then transferred to the first to fourth gas-liquid separators 3, 6, 9 .
12, first to fourth heat exchangers 4, 7, 10.13 and first to fourth capillary tubes 5, 8, 11.
14, those with higher boiling points are returned to the compressor 1 side in order, and the refrigerants with the lowest boiling points are returned to the fourth heat exchanger 13.
It is condensed and sent to the fifth gear pillar tube 15 in the lowest temperature section 30.

The refrigerant sent to the fifth gear pillary tube] 5 is
There, it is expanded under reduced pressure and vaporized, and after absorbing heat from the secondary refrigerant in the cooler 6, it returns to the compressor.

On the other hand, the secondary refrigerant that has been cooled and condensed in the cooler] 6 absorbs heat from the object to be cooled 23 in the cooling coil 17 and is vaporized, and then returns to the cooler 16. As a result, the object to be cooled 23 is cooled to an extremely low temperature.

(Problems to be Solved by the Invention) However, conventional cooling devices have been developed only to obtain extremely low temperatures, and have had the problem of not being able to expand the temperature setting range of the object to be cooled.

That is, since the object to be cooled 23 is cooled in a temperature range around the boiling point of the secondary refrigerant, the object to be cooled 23 cannot be cooled at a temperature outside this temperature range. For this reason,
For example, the device shown in FIG. 9 could not be used in test equipment that requires a wide temperature setting range.

In order to deal with such problems, it is conceivable to expand the temperature setting range by adding a powerful heating means to the conventional cooling device and heating the secondary refrigerant.

However, in doing so, the temperature of the lowest temperature section 30 also rises, and the cooler 16 is closed, and each heat exchanger 13.1.0,
The temperature of 7.4 also rises sequentially. As a result, the refrigerant components are gasified in the refrigeration cycle in descending order of boiling point, and the pressure within the refrigeration cycle increases. In this way, the balance of the refrigeration cycle is lost, and as a result, the temperature and pressure exceed the allowable limits of the compressor 1, making cooling operation impossible.

(Objective of the Invention) A first object of the present invention is to provide a cooling device that can expand the temperature setting range of the object to be cooled without disturbing the balance of the refrigeration cycle.

A second object of the present invention is to provide a cooling device that can finely adjust the temperature of an object to be cooled, in addition to achieving the first object.

A third object of the present invention is to provide a cooling device that can automatically adjust the temperature of an object to be cooled to a desired set temperature in addition to achieving the second object.

(Means for Solving the Problems) The invention according to claim 1 is characterized in that a multi-component mixed refrigerant is sealed in a refrigerant circulation path passing through a compressor and a condenser, and the refrigerant gas after passing through the condenser is In order to achieve the first object, the cooling device is an indirect cooling type cooling device that performs liquid separation and expansion in multiple stages and performs heat exchange between the refrigerant and the object to be cooled via a secondary refrigerant. A plurality of secondary refrigerant circulation paths are inserted in parallel between the flow path of the refrigerant component having a lower boiling point among the two refrigerant components mutually separated by the final stage gas-liquid separation and the side of the object to be cooled. , in each of the plurality of secondary refrigerant circulation paths, secondary refrigerants having different boiling points (even if the same type of refrigerant is changed, the boiling point will be different) are sealed in each of the plurality of secondary refrigerant circulation paths; Provide a flow rate adjustment valve.

The invention according to claim 2 is the cooling device according to claim 1, in which, in order to achieve the second object, temperature of each secondary refrigerant is controlled in the vicinity of each of the plurality of secondary refrigerant circulation paths. A heater is provided for fine adjustment.

The invention according to claim 3 is the cooling device according to claim 2, in which, in order to achieve the third object, there is provided a temperature detecting means for detecting the temperature of the object to be cooled, and a temperature detecting means from the temperature detecting means. The cooling apparatus further includes a control means for controlling the drive amount of each of the flow rate regulating valves and each of the heaters based on the output signal of, and adjusting the temperature of the object to be cooled to a desired set temperature.

(Function) In the cooling device according to claim 1, by filling the plurality of secondary refrigerant circulation paths with secondary refrigerants having different boiling points, a temperature difference is created between each circulation path due to the boiling point difference of the secondary refrigerants. arise. Therefore, by adjusting the opening degree of each flow rate regulating valve, the temperature of the object to be cooled can be changed over a wide range based on the temperature difference.

In the cooling device according to the second aspect, heaters are provided in the plurality of secondary refrigerant circulation paths. Therefore, by adjusting the drive amount of each heater, the temperature of the secondary refrigerant in each circulation path can be finely adjusted.

In the cooling device according to claim 3, the temperature detection means and the control means are provided, and means for controlling the drive amount of each flow rate regulating valve and each heater based on the output signal from the temperature detection means is provided. The temperature of the object to be cooled is automatically adjusted to the desired set temperature.

(Example) A. First Example (A-1), Structure FIG. 1 is a circuit diagram of a cooling device that is a first example of the present invention. As shown in the figure, a mixed refrigerant in which a plurality of refrigerant components having different boiling points are mixed is sealed in the refrigerant path of this cooling device. This refrigerant path is connected to the compressor 1
The gas is introduced from the discharge port 01 through the condenser 102 to the first gas-liquid separator 103. The gas phase outlet of the first gas-liquid separator 103 is connected to the second gas-liquid separator 106 via the first heat exchanger 104, and similarly, the second and third gas-liquid separators 106, 109 The gas phase outlets of are connected to third and fourth gas-liquid separators 109, 112 via second and third heat exchangers 1.07, 110, respectively.

The refrigerant path drawn out from the gas phase outlet of the fourth gas-liquid separator 112 is guided to the lowest temperature section 130 through the fourth heat exchanger 113. In the lowest temperature section 130, on the refrigerant path,
A fifth capillary reach tube (expansion means) 115, a first cooler 140, and a second cooler 150 are provided in series in order from the upstream side with respect to the flow direction of the refrigerant.

The refrigerant path (refrigerant return line) drawn out from the second cooler 150 connects the fourth to first heat exchangers 113, 110,
It passes through 107 and 104 in order and is connected to the compressor 101.

Moreover, the first to fourth gas-liquid separators 103, 106.1.
The liquid phase outlets of 09 and 112 are connected to the first to fourth capillary reach tubes (expansion means) 105, 108, 11, respectively.
1 and 114 to the inlet sides of the first to fourth heat exchangers 104107 and 110 and 113 in the refrigerant return line, respectively.

On the other hand, first and second brine circuits (secondary refrigerant circulation path) 141. ．． 151 is provided. In other words, these brine circuits 141 and 151 are inserted in parallel between the lowest temperature section 130 and the object to be cooled 123. The first brine circuit 141 includes an object to be cooled 1
A cooling coil 143 provided on the cooling coil 143 side, a refrigerant transfer pipe (outward path) 142 for transferring secondary refrigerant such as brine from the first cooler 143 to the cooling coil 143, and a cooling coil 143 provided on the cooling coil 143 side. A refrigerant return pipe (return path) 144 for returning the secondary refrigerant to the cooler 140 is provided. Further, a flow rate adjustment valve V1 such as a solenoid valve is provided on the refrigerant transfer pipe 142 to adjust the supply amount of the secondary refrigerant. Further, a heater H1 is arranged near the refrigerant transfer pipe 142 to finely adjust the temperature of the secondary refrigerant.

Also, in the second brine circuit 152, a refrigerant transfer pipe 152, a cooling coil 153. Refrigerant return pipe 154. A flow rate regulating valve V2 such as a solenoid valve and a heater H2 are provided.

In this cooling device, a plurality of mixed refrigerants having different boiling points are sealed in the refrigeration cycle side, as described above.

In addition, secondary refrigerants having different boiling points (for example, Freon R13,
and R14) are each included. In this case, the first
The boiling point of the secondary refrigerant on the brine circuit 141 side is made lower than that on the second brine circuit 151 side.

(A-2) Operation Next, the operation of this cooling device will be explained with reference to the refrigerant temperature distribution graph shown in FIG.

First, the high temperature, high pressure mixed gas refrigerant discharged from the compressor 101 is cooled by water or air in the condenser 102, and a portion is condensed to become a gas-liquid mixed refrigerant, which enters the first gas-liquid separator 103. . Here, the gas-liquid mixed-phase refrigerant is separated into a gas-phase refrigerant and a liquid-phase refrigerant, and the gas-phase refrigerant is sent to the first heat exchanger 104. On the other hand, the liquid phase refrigerant is fed into the first capillary reach tube 105, where it is decompressed and expanded, and then joins the refrigerant return line that returns to the compressor 101. In addition, in FIG. 2, each gas-liquid separator 103,
The temperature distribution of the refrigerant flowing out from the liquid phase outlets 106, 109, and 11.2 is omitted.

The gas-phase refrigerant sent from the first gas-liquid separator 103 to the first heat exchanger 104 is cooled by heat exchange with the return refrigerant in the return line, and a part of the refrigerant is condensed to become a gas-liquid multiphase refrigerant. It enters the second gas-liquid separator 106.

Second to fourth gas-liquid separators 106, 109, 112, second to fourth capillary reach tubes 108, 111, 1
14 and second to fourth heat exchangers 107, 110, 1
13, the same action as above is repeated. As a result, the mixed refrigerant is gradually cooled and returned to the compressor 101 in the order of the highest boiling point. In this way, the component with the lower boiling point of the two components separated from each other in the final stage gas-liquid separator 112, that is, the gas with the lowest boiling point among all the components of the mixed refrigerant, is used as the refrigerant. It is fed into the exchanger 113, where it is cooled and condensed, and then fed into the fifth capillary reach tube 115.

Next, the liquid refrigerant is transferred to the fifth capillary reach tube 1.
At step 15, it is expanded under reduced pressure to become a gas-liquid mixed phase state, and is sent to the first cooler 140. The gas-liquid multiphase refrigerant in the first cooler 140 absorbs heat from the secondary refrigerant in the first brine circuit 141 and is partially evaporated before being sent to the second cooler 150 .

In the second cooler 150, the refrigerant component is supplied to the second brine circuit 1.
It absorbs heat from the secondary refrigerant of 51 and evaporates.

The gas refrigerant that has exited the second cooler 150 sequentially passes through the fourth and first heat exchangers 113, 110, 107, and 104, increasing its own temperature, and finally becomes a low-pressure gas at room temperature and is compressed. Return to machine 1.

On the other hand, the secondary refrigerant cooled and condensed in the first cooler 140 passes through the refrigerant transfer pipe 142 and absorbs heat from the object to be cooled 123 through the cooling coil 143 and is vaporized, and is vaporized in the refrigerant return pipe 144.
and returns to the first cooler 1.40.

Further, the secondary refrigerant condensed in the second cooler 150 is transferred to the object to be cooled 123 within the cooling coil 153 in the same manner as described above.
After absorbing heat and vaporizing it, it returns to the second cooler 150.

In this way, the object to be cooled 123 is cooled to an extremely low temperature.

(A-3>, Temperature setting range of the first embodiment In the cooling device of this first embodiment, the brine circuit 141 1
Since the secondary refrigerants 51 each have a different boiling point, a temperature difference occurs between the cooling coils 143 and 153 of the first and second brine circuits 141 and 151, as shown in FIG. Therefore, by adjusting the opening degrees of the flow rate adjustment valves Vl and V2, the temperature of the object to be cooled 123 can be changed over a wide range based on the temperature difference.

Therefore, the temperature setting range can be expanded.

Incidentally, in the cooling device of this embodiment, when compared with the cooling device shown in FIG. 9, the temperature setting range can be expanded nearly twice.

In addition, the opening degree adjustment of valves Vl and V2 depends on the object to be cooled 1.
23, or in that case, the temperature can be finely adjusted by adjusting the power supplied to the heaters H1 and H2. That is, since these heaters H1 and H2 are used for fine adjustment of temperature, the power supplied to them may be relatively small. Therefore, the temperature of the entire refrigeration cycle does not rise significantly due to the heat generated by the heaters H1 and H2.

B. Second Embodiment FIG. 3 is a circuit diagram of a cooling device which is a second embodiment of the present invention. As shown in the figure, the difference between the cooling device of this second embodiment and the cooling device of the first embodiment is that in the cooling device of the first embodiment, the second cooler 150 is
While the cooler 140 is provided on the downstream side in the refrigerant flow direction, in the cooling device of this second embodiment, the second cooler 150 is provided on the upstream side of the fifth capillary reach tube 115. It is a point.

The other configurations are the same as the cooling device of the first embodiment shown in FIG. 1 above.

In the cooling device of this second embodiment, as shown in FIG.
The secondary refrigerant is cooled. For this reason, the second
A relatively high boiling point can be used as the secondary refrigerant of the brine circuit 151, and the temperature difference between the cooling coil 143 of the first brine circuit 140 and the cooling coil 153 of the second brine circuit 150 can be It can be made larger than that of the first embodiment. Therefore, the temperature setting range can be further expanded than that of the first embodiment.

C1 Third Embodiment (C-1), Configuration FIG. 5 is a circuit diagram of a cooling device that is a third embodiment of the present invention. As shown in the figure, in addition to the configuration of the cooling device of the second embodiment, the cooling device of the third embodiment includes a temperature sensor] 60 provided on the object to be cooled 123, and a control device 170. It is equipped with The control device 170 includes a microcomputer and a set temperature input means.

Then, when a desired set temperature is set in the control device 170, the control device 170 is activated and the flow rate adjustment valves Vl, V
2 and selectively control the drive amount of heaters H1 and H2,
The operations described below are performed.

(C-2) Operation Next, the operation of the cooling device of the third embodiment will be explained with reference to the flowchart of FIG. 6, and FIGS. 7 and 8. In this case, the description will be made assuming that the set temperature of the object to be cooled 123 is To.

In addition, in FIGS. 6 to 8, T1 indicates the boiling point of the refrigerant sealed in the first brine circuit 141, and T2
indicates the boiling point of the refrigerant in the second brine circuit 151, and the relationship Tl<T2 holds between them. Tc is a control boundary temperature, which is the boundary temperature between whether the temperature is controlled on the first brine circuit 141 side or the second brine circuit 151 side. This control boundary temperature Tc is generally predetermined within the range of TI<TC<T2. In this example, it is determined from the relational expression Tc - (T1+T2)/2.

ΔTf is a fine adjustment tolerance, and control is performed so that the temperature of the object to be cooled 123 ultimately falls within the range of ±ΔTf from the set temperature TO. This ΔTf is determined in advance based on the performance of the cooling device and the like.

ΔTf is a rough adjustment tolerance, and based on this value, it is determined whether the temperature is controlled by the valves Vl and V2 or the heaters H1 and H2. This is the valve Vl, V2
This is predetermined according to the limit of temperature adjustment ability.

As shown in FIG. 6, first, the control device 170
When o is input, the temperature of the cooled body 123 is detected by taking in the signal from the temperature sensor 160 in step S1.

Next, in step S2, valve v1. It is determined whether adjustment of v2 and heaters H1 and H2 is necessary. In other words,
The detected temperature Ts detected in step S1 is the set temperature To
Within the allowable range of (TO-ΔTf) and (To-ΔT
f) (within the range indicated by the diagonal line ■ in FIG. 8).

If the detected temperature Ts is within the allowable range, there is no need to change the temperature adjustment conditions, and the process returns to step S1.

On the other hand, if the detected temperature Ts is outside the allowable range, step S3
to move to.

In step S3, it is determined whether the temperature adjustment is to be performed using the valve VI V2 or the heaters H1 and H2. That is, the detected temperature Ts is closer to the set temperature To than the limit of the adjustment ability of the valves Vl and V2, and the temperature is not adjusted by the heaters H1 and H2, but the temperature is adjusted by the valve v1. Within the range in which the temperature should be adjusted by v2, that is, (To-ΔTr) and (To-ΔT
f) (within the range indicated by diagonal lines ■ in FIG. 8). The reason why area ■ is set only to the lower temperature side than the set temperature To is because the heaters H1 and H2 only have heating capacity, so when the temperature is higher than the set temperature TO, the temperature is set by the valves Vl and V2. This is because the temperature must be adjusted using the heaters H1 and H2 instead of adjustment. The detected temperature Ts is outside the above range (diagonal line ■ in Figure 8)
, ■), the temperature is adjusted using the valves Vl and V2, and the process moves to step S4.

In step S4, it is determined which of the valves Vl, V2 is to be operated. In other words, if the detected temperature Ts is lower than the control boundary temperature Tc (within the range indicated by the symbol ■ in FIG. 7), the temperature is adjusted by the valve V1 in step S6; ), the temperature is adjusted by valve v2 in step S7.

When operating the valve V1, the step S6 calculates a transfer function G1 (S ) is used.

That is, the amount (valve operation amount) Δ■ straddle valve v1 is operated by applying the inverse operator of the transfer function G L (s) to the difference between the detected temperature Ts and the set temperature To.

Also in step S7, the transfer function G2(S) indicating the response of the system to the manipulated variable of the valve V2 is used to determine the valve manipulated variable ΔV2, and the valve V2 is automatically operated by the manipulated variable Δv2.

On the other hand, in step S3, the detected temperature Ts is
Within the range of temperature adjustment according to 2 (within the range marked by diagonal lines ■ in Figure 8)
If so, the temperature will be adjusted by the heaters H1 and H2, and the process will proceed to step S5.

In step S5, it is determined which of the heaters H1 and H2 is to be operated. Here, similarly to step S4, if the detected temperature Ts is lower than the control boundary temperature Tc (within the range of symbol H in FIG. 7), the temperature is adjusted by the heater H1 in step S8; (If it is within the range indicated by symbol I in FIG. 7), the temperature is adjusted by the heater H2 in step S9.

In step S8 S9, similarly to step 5687, transfer functions F (s) and F 2 (s) indicating the response of the system to the manipulated variables of heaters H1 and H2 are used to determine heater manipulated variables ΔH1 and ΔH2. The heater H1 or H2 is operated by the amount ΔH1, ΔH.

After passing through steps S6 to S9, the process returns to step S1.

(C-3) Specific Example Next, the operation of the cooling device of the third embodiment will be explained using a specific example.

In this case, it is assumed that the set temperature TO is higher than Tc and within the range indicated by reference numeral I in FIG. Initial cooled body 123
The temperature (initial detected temperature) Ts is higher than To+Tf and within the range indicated by the diagonal line (■) in FIG. 8, and is lower than T2.

First, in step S1, the temperature of the object to be cooled 123 is detected.

Next, in step S2, since the detected temperature Ts in step S1 is out of the allowable range (diagonal line ■ in Figure 8),
The process moves to step S3.

Next, in step S3, the detected temperature Ts is out of the hitter operation range (hatched ■ in Figure 8), so step S4
to move to.

In step S4, the detected temperature Ts is higher than the control boundary temperature Tc, so the process moves to step S7, where the manipulated variable Δ
The V-straddle valve V2 is operated in the closing direction.

By this operation, when TI<Ts<T2, the second brine circuit [4] acts to give heat to the object to be cooled 123, so the temperature of the object to be cooled 123 decreases.

In this way, the temperature or heater operation range (hatched line ■ in Figure 8)
It is assumed that the temperature has shifted to within the control boundary temperature Tc and has become lower than the control boundary temperature Tc (within the range indicated by the symbol ■ in FIG. 7).

Subsequently, in steps Sl and S2, the temperature of the object to be cooled 123 is detected, and since the detected temperature Ts is outside the allowable range (as shown by the diagonal line ■ in FIG. 8), the process moves to step S3.

Then, in step S3, the detected temperature Ts is within the heater operation range (hatched ■ in FIG. 8), so the process moves to step S5.

In step S5, the detected temperature Ts is lower than the control boundary temperature Tc (within the range indicated by the symbol ■ in FIG. 7), so the process moves to step S8.

Then, in step S8, the manipulated variable ΔH] height H1 is automatically operated in a direction to increase its calorific value.

With this operation, the temperature of the object to be cooled 123 increases slightly,
It is assumed that the temperature has shifted to within the permissible range (diagonal line ■ in Figure 8).

Subsequently, in steps St, S2, the temperature of the object to be cooled 123 is detected, and since the detected temperature Ts is within the permissible range (hatched black in FIG. 8), the process returns to step S1.

Thereafter, steps Sl and S2 are repeated unless the set temperature To is changed or the temperature of the object to be cooled 123 changes.

Note that when starting cooling of the object to be cooled 123, each valve Vl
, V2 is left fully open, and it is desirable to proceed to the feedback routine after the temperature of the object to be cooled 123 has sufficiently decreased.

(C-4) Effects of the third embodiment According to the cooling device of the third embodiment, the temperature sensor]5
0 and a control device 160 to control the flow rate adjustment valves y1.0 and y1.0 based on the signal from the temperature sensor 150. Since the temperature of the object to be cooled 123 is adjusted by automatically controlling the drive of V2 and the heaters H1 and H2, in addition to the effects of the second embodiment, the temperature of the object to be cooled 123 can be adjusted to a desired level. It can automatically adjust to the set temperature.

D. Modification In each of the above embodiments, the first and second brine circuits 141
．． ．． Although different types of secondary refrigerants having different boiling points are sealed in the refrigerant 151, it is also possible to use the same type of secondary refrigerants. For example, the pressures of the secondary refrigerants charged into the first and second brine circuits 141 and 151 may be changed to make the boiling points of the secondary refrigerants different from each other. In this case, the brine circuit with higher pressure (higher boiling point) may be used as the second brine circuit 151.

In addition, in each of the above embodiments, the coolers 1, 40 and 150 are
Although the case where a cooler is provided has been described, three or more coolers may be provided.

Furthermore, the temperature sensor 160 and control device 170 described in the third embodiment may be provided in the cooling device of the first embodiment to automatically adjust the temperature of the object to be cooled 123.

Although it is preferable to provide heaters H1 and H2 for fine adjustment of temperature, temperature adjustment is possible if at least valve VI V2 is provided.

(Effects of the Invention) As described above, according to the cooling device according to claim 1, secondary refrigerants having different boiling points are filled in the plurality of secondary refrigerant circulation paths, so that A temperature difference is generated due to the boiling point difference of the secondary refrigerant, and the first effect is that the temperature setting range of the object to be cooled can be expanded.

According to the cooling device according to the second aspect, since a heater is provided in each secondary refrigerant circulation path of the cooling device according to the first aspect, in addition to the above-mentioned first effect, the drive amount of each heater is further reduced. By adjusting, the temperature of the secondary refrigerant in each circulation path can be finely adjusted.

Therefore, the second effect of being able to finely adjust the temperature of the object to be cooled is obtained.

According to the cooling device according to claim 3, the cooling device according to claim 2 is provided with temperature detection means and control means, and the drive amount of each flow rate regulating valve and each heater is controlled based on the temperature detection means. Since the temperature of the object to be cooled is adjusted, in addition to the second effect described above, there is a third effect that the temperature of the object to be cooled can be automatically adjusted to a desired set temperature. .

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of a cooling device which is a first embodiment of this invention, Fig. 2 is a graph showing the temperature distribution of the refrigerant in the device, and Fig. 3 is a cooling device which is a second embodiment of this invention. A circuit diagram of the device, FIG. 4 is a graph showing the temperature distribution of the refrigerant in the device, FIG. 5 is a schematic configuration diagram of a cooling device according to the third embodiment of the present invention, and FIG. 6 shows the operation of the device. Flowcharts for explanation; FIGS. 7 and 8 are explanatory diagrams related to the flowchart of FIG. 6, respectively; FIG. 9 is a circuit diagram of a conventional cooling device. 10]... Compressor, 102. Condenser, 103.
106,109,112・Gas-liquid separator, 104.107
．． 11 11.3 ・, heat exchanger, 105.108,
111,114.115... Capillary tube, 140.150... Cooler, 141.151... Brine circuit, 160... Temperature sensor, 170... Control device, H
l, H2...Heater, TI, T2...Boiling point, Vl
, V2...Flow rate adjustment valve Figure 71, T2: Secondary refrigerant boiling point diagram

Claims (3)

[Claims] (1) A multi-component mixed refrigerant is sealed in a refrigerant circulation path passing through a compressor and a condenser, and the refrigerant after passing through the condenser is subjected to gas-liquid separation and expansion in multiple stages, while being exposed to the refrigerant. In an indirect cooling type cooling system in which heat exchange with the cooling body is performed via a secondary refrigerant, the flow of the refrigerant component with the lower boiling point of the two refrigerant components mutually separated in the final stage of gas-liquid separation. A plurality of secondary refrigerant circulation paths are inserted in parallel between the cooling medium and the object to be cooled, and secondary refrigerants having different boiling points are respectively sealed in the plurality of secondary refrigerant circulation paths; A cooling device characterized in that a flow rate regulating valve is provided in each of the secondary refrigerant circulation paths. (2) The cooling device according to claim 1, wherein a heater for finely adjusting the temperature of each secondary refrigerant is provided near each of the plurality of secondary refrigerant circulation paths. (3) The cooling device according to claim 2, further comprising: temperature detection means for detecting the temperature of the object to be cooled; and based on an output signal from the temperature detection means, each of the flow rate regulating valves and each of the heaters A cooling device further comprising: a control means for adjusting the temperature of the object to be cooled to a desired set temperature by controlling the amount of drive of the cooling device.