JP2014145503A - Cooling device and radiation detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling device which achieves downsizing and low power consumption compared to a conventional cooling device, and to provide a radiation detection device including the cooling device.SOLUTION: A cooling device includes: a heat sink heat transfer body 13 having a cooling surface that may thermally connect with a cooling object surface of a cooling object; a first peltier element 30 where an endotherm surface is thermally connected with a surface of the heat sink heat transfer body 13 which is opposite to the cooling surface; a first liquid-cooled heat sink 40 which is thermally connected with a heating surface of the first peltier element 30 and has a passage for circulating a refrigerant therein; a second liquid-cooled heat sink 50 having a passage connected with the passage of the first liquid-cooled heat sink 40 therein; second peltier elements 52a, 52b where endotherm surfaces are thermally connected with the second liquid-cooled heat sink 50; and a circulation mechanism which circulates the refrigerant between the first liquid-cooled heat sink 40 and the second liquid-cooled heat sink 50.

Description

  The present invention relates to a cooling device and a radiation detection device including the cooling device.

  Research and development of an imaging device using a Compton camera is progressing as a next-generation molecular imaging technology in nuclear medicine. Molecular imaging technology in nuclear medicine refers to the administration of a radiopharmaceutical that has the function of emitting radiation such as gamma rays to substances that tend to gather in parts that exhibit a specific state in the body, such as cancer cells, and that specific state. This is a technique for detecting and imaging radiation emitted from a region. A Compton camera is a device that uses Compton scattering kinematics to image the spatial intensity distribution of a gamma-ray source. Generally, a semiconductor radiation detector that functions as a scatterer and a semiconductor radiation detector that functions as an absorber. It is configured by stacking elements. Examples of the radiation detection element used in the Compton camera include those using cadmium telluride (CdTe).

  An imaging apparatus using a Compton camera requires a cooling mechanism for cooling the radiation detection element in order to enable continuous imaging. For example, a radiation detection element using cadmium telluride (CdTe) is preferably used in an environment cooled at about −20 ° C.

  Patent Document 1 discloses a front Peltier element that is thermally connected to an object to be cooled, a rear Peltier element that is thermally connected to the front Peltier element to cool the front Peltier element, and a cooling mechanism for the rear Peltier element. Water cooling means thermally connected to the rear Peltier element, a front temperature control unit that drives the front Peltier element, and a rear that drives the rear Peltier element so that the high temperature side temperature of the rear Peltier element is higher than the outside air temperature. An analyzer cooling machine including a temperature control unit is disclosed.

JP 2010-255915 A

  FIG. 1 shows a configuration example of a radiation detection apparatus 100 including a cooling mechanism. A radiation detection element 10 including a semiconductor such as cadmium telluride (CdTe) is accommodated in a sealed container 104. A liquid cooling heat sink 106 is thermally connected to the bottom surface of the radiation detection element 10. The liquid cooling heat sink 106 is provided with a circulation channel for circulating the liquid refrigerant inside. One end of the circulation channel is connected to a supply port 106a for introducing the liquid refrigerant into the circulation channel, and the other end of the circulation channel is a discharge for discharging the liquid refrigerant from the circulation channel. It is connected to the outlet 106b.

  The supply port 106a and the discharge port 106b are connected to one end portions of the heat insulating hoses 108a and 108b, respectively, and the other end portions of the heat insulating hoses 108a and 108b are connected to the low temperature circulating water tank 110, respectively. The low-temperature circulating water tank 110 is a device that cools and supplies the liquid refrigerant circulating in the water tank to the outside. The liquid refrigerant cooled in the low-temperature circulating water tank 110 is supplied to the circulation flow path of the liquid-cooled heat sink 106 via the heat insulating hose 108a and the supply port 106a, and after cooling the radiation detection element 10, the discharge port 106b and It returns to the low temperature circulating water tank 110 via the heat insulation hose 108b. Thus, in the radiation detection apparatus 100, the liquid-cooled heat sink 106 for cooling the radiation detection element 10 and the low-temperature circulating water tank 110 are arranged apart from each other, and a heat insulation hose 108a and 108b having a length of several meters is provided between them. It has a connected configuration.

  Thus, in the structure which cools the radiation detection element 10 using the low temperature circulating water tank 110, the scale of an apparatus becomes large easily and size reduction is difficult. Further, since the apparatus scale is large, it takes a relatively long time to stabilize the radiation detection element 10 at a desired temperature. In the case of this configuration, when maintaining the temperature of the radiation detection element 10 at, for example, −20 ° C., a cooling preparation period of about 2 to 3 hours is required.

  Moreover, in the structure using the low temperature circulating water tank 110, the electric power consumption in the low temperature circulating water tank 110 is large, and it is difficult to perform power saving of the whole apparatus. For example, when the temperature of the radiation detection element 10 is to be maintained at −20 ° C., power of about 600 W is consumed only by the cooling mechanism.

  Further, in the configuration in which the liquid cooling heat sink 106 is disposed immediately below the radiation detection element 10 and the radiation detection element 10 is cooled by the liquid refrigerant circulating in the liquid cooling heat sink 106, the temperature of the radiation detection element 10 is set to, for example, −20 ° C. When maintaining, a liquid refrigerant of −20 ° C. will flow in the heat insulating hoses 108a and 108b. Therefore, as a countermeasure against dew condensation on the heat insulating hoses 108a and 108b, the thickness of the heat insulating material constituting the heat insulating hoses 108a and 108b needs to be about 30 mm. As a result, the diameter of the heat insulating hoses 108a and 108b is about 70 mm. However, when the diameters of the heat insulating hoses 108a and 108b are increased, the flexibility of the heat insulating hoses 108a and 108b is significantly impaired. In this case, it becomes difficult to arrange the radiation detection element 10 and the low-temperature circulating water tank 110 close to each other, and a sufficiently large installation space is required. Further, when the flexibility of the heat insulating hoses 108a and 108b is impaired, vibration generated in the low temperature circulating water tank 110 is easily propagated to the radiation detection element 10, and the image quality of an image photographed by the radiation detection element 10 is adversely affected. There is a fear.

  Thus, in the structure which cools the radiation detection element 10 using the low temperature circulating water tank 110, an apparatus scale and power consumption are large, and size reduction and reduction in power consumption are difficult. The Compton camera can also be used for radiation spatial distribution surveys at the Fukushima nuclear plant. Unlike positron emission diagnostic imaging (PET), the Compton camera has the advantage that a three-dimensional image of the radiation distribution can be acquired without surrounding the measurement object on the circumference. For this reason, it is conceivable to carry out a wide-area survey or the like by mounting on a helicopter or the like. Equipment weight, size, and continuous drive time are important factors affecting the success or failure of fieldwork. For this reason, in order for the Compton camera experiment currently performed at the laboratory level to be put into practical use in the future, further downsizing, weight reduction, and low power consumption are required for taking it out to the field.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a cooling device and a radiation detection device including the cooling device that can be reduced in size and power consumption as compared with the related art. And

  In order to achieve the above object, a cooling device according to the present invention includes a heat transfer body having a cooling surface thermally connectable to a cooling target surface of an object to be cooled, and the cooling surface of the heat transfer body. A first Peltier element having an endothermic surface thermally connected to the opposite surface, and a first flow path thermally connected to the heat generating surface of the first Peltier element and circulating a refrigerant therein. A liquid-cooled heat sink, a second liquid-cooled heat sink having a flow path connected to the flow path of the first liquid-cooled heat sink, and an endothermic surface are thermally connected to the second liquid-cooled heat sink. A second Peltier element; and a circulation mechanism for circulating the refrigerant between the first liquid-cooled heat sink and the second liquid-cooled heat sink.

  The cooling device according to the present invention may further include a heat insulating cover that is provided so as to cover the object to be cooled and blocks heat conduction and heat radiation to the object to be cooled.

  The cooling device according to the present invention may further include a heat insulating material provided so as to be in contact with the surface to be cooled and covering the heat transfer body so as to expose the cooling surface of the heat transfer body.

  Further, the first Peltier element and the second Peltier element may have a one-stage configuration.

  Moreover, the said heat insulation cover may be comprised including the vacuum heat insulating material obtained by coat | covering the core material with low thermoelectric power with the film which has heat insulation, and reducing the inside and sealing.

  Further, the heat insulating cover is composed of a plurality of vacuum heat insulating materials that are bent so as to form a plurality of surfaces corresponding to the surfaces of the heat insulating cover, and each surface of the heat insulating cover includes a plurality of surfaces. You may have the laminated structure which laminated | stacked these vacuum heat insulating materials.

  The circulation mechanism includes a heat-insulating hose having flexibility connected to the flow path of the first liquid-cooled heat sink and the flow path of the second liquid-cooled heat sink, a pump coupled to the heat-insulating hose, May be included.

  Moreover, the cooling device according to the present invention may further include a sealed container that is provided inside the heat insulating cover and accommodates the object to be cooled.

  Moreover, the radiation detection apparatus which concerns on this invention is comprised including said cooling device, and contains the radiation detection element thermally connected to the heat absorption surface of a said 1st Peltier element as said cooling target object.

  According to the cooling device and the radiation detection device of the present invention, it is possible to achieve downsizing and lower power consumption than in the past.

It is a figure which shows the structure of the radiation detection apparatus provided with the cooling mechanism. It is a figure which shows the structure of the radiation detection apparatus containing the cooling device which concerns on embodiment of this invention. It is sectional drawing of the heat insulating material which comprises the heat insulation cover which concerns on embodiment of this invention. Fig.4 (a) is sectional drawing which shows the mode of the heat conduction in the heat insulating material which concerns on embodiment of this invention. FIG. 4B is a diagram showing the relationship between the distance X from the end of the heat insulating material and the amount of heat Q transferred. It is sectional drawing which shows the movement path | route of the heat | fever when two heat insulating materials are piled up. Fig.6 (a) is a perspective view which shows the preparation method of the heat insulation cover using the some heat insulating material which concerns on embodiment of this invention. FIG. 6B is a top view of the heat insulating cover according to the embodiment of the present invention. The temperature and power consumption of each part of a cooling device in the case of maintaining the temperature of the bottom face of the radiation detection element which concerns on embodiment of this invention at -20 degreeC are shown. It is a figure which shows the structure of the radiation detection apparatus which concerns on a comparative example.

  Embodiments of the present invention will be described below with reference to the drawings. In each drawing, the same reference numerals are given to the same or equivalent components and parts.

  FIG. 2 is a diagram illustrating a configuration of the radiation detection apparatus 1 including the cooling device according to the embodiment of the present invention. The radiation detection apparatus 1 constitutes a so-called Compton camera, and is an apparatus that detects radiation such as gamma rays emitted from the outside by the radiation detection element 10, images the radiation density distribution of the radiation source, and outputs the image. Note that the radiation detection apparatus 1 may detect radiation other than gamma rays such as X-rays. Moreover, the radiation detection element 10 is corresponded to the cooling target object in the cooling device which concerns on this embodiment.

  The radiation detection element 10 includes, for example, a stacked body in which each of a plurality of semiconductor layers functioning as a scatterer and each of a plurality of semiconductor layers functioning as an absorber is stacked, and this stacked body is accommodated in a case. Configured. Note that silicon (Si) or the like that easily causes Compton scattering can be used as the semiconductor layer functioning as a scatterer. As the semiconductor layer functioning as an absorber, cadmium telluride (CdTe) or the like that can absorb scattered photons with high probability can be used.

  The radiation detection element 10 is housed in a sealed container 20 and is placed on a heat insulating material 12 configured by urethane foam or the like housed in the sealed container 20. The sealed container 20 is made of a synthetic resin such as acrylic having a relatively low thermal conductivity, and is placed on the upper surface of the mounting table 22. In the present embodiment, the inside of the sealed container 20 is set to normal pressure (atmospheric pressure), but the inside of the sealed container 20 may be set to a pressure lower than atmospheric pressure as necessary.

  The heat insulating cover 80 covers the outside of the sealed container 20 so as to accommodate the entire sealed container 20 therein. The heat insulating cover 80 is composed of a heat insulating material 81 (see FIG. 3) that blocks heat conduction and heat radiation from the outside to the radiation detection element 10. The detailed configuration of the heat insulating cover 80 will be described later.

  The mounting table 22 is supported on the detector table 28 by a plurality of support columns 24, and a radiation detection signal output from the radiation detection element 10 is processed in a space below the mounting table 22 formed by the support columns 24. A signal processing unit 26 is provided.

  The bottom surface of the radiation detection element 10 is connected to the upper surface of the heat sink heat transfer body 13 constituted by a member having a relatively high thermal conductivity such as a metal having a thickness of about 30 to 40 mm. The bottom surface of the radiation detection element 10 corresponds to the cooling target surface of the cooling device according to the present embodiment, and the upper surface of the heat sink heat transfer body 13 corresponds to the cooling surface of the cooling device according to the present embodiment. The heat insulating material 12 is provided so as to be able to come into contact with the bottom surface (cooling target surface) of the radiation detection element, and is provided so as to expose the top surface (cooling surface) of the heat sink heat transfer body 13. Thereby, the heat conduction from the outside to the radiation detection element 10 and the heat sink heat transfer body 13 is cut off.

  The lower surface of the heat sink heat transfer body 13 is exposed to the lower surface side of the mounting table 22 through a through hole 22 a formed in the mounting table 22. The lower surface of the heat sink heat transfer body 13 is connected to the heat absorption surface (low temperature side) of the first Peltier element 30 having a one-stage configuration. That is, the heat absorption surface of the first Peltier element 30 is thermally connected to the bottom surface of the radiation detection element 10. The one-stage configuration refers to a configuration in which Peltier elements including a pair of heat absorbing surfaces and heat generating surfaces are used without being stacked. The endothermic surface of the first Peltier element 30 is controlled by a controller (not shown) so as to maintain the temperature of the bottom surface of the semiconductor element 10 at a desired temperature (for example, −20 ° C.). The heat generating surface (high temperature side) of the first Peltier element 30 is thermally connected to the first liquid-cooled heat sink 40. In the present embodiment, the heat-sink heat transfer body 13 is provided between the first Peltier element 30 and the radiation detection element 10 to keep the heat generation surface of the first Peltier element 30 away from the radiation detection element 10. Thereby, the influence with respect to the radiation detection apparatus 10 of the radiant heat emitted from the heat generating surface of the 1st Peltier element 30 can be made small.

  The first Peltier element 30 and the first liquid-cooled heat sink 40 are accommodated inside a heat insulating material 14 made of urethane foam or the like provided on the lower surface side of the mounting table 22, and the first Peltier element 30. And the heat conduction from the outside to the 1st liquid cooling heat sink 40 is intercepted.

  The first liquid-cooled heat sink 40 is provided with a circulation channel for circulating the liquid refrigerant therein. One end of the circulation channel is connected to a supply port 40a for introducing the liquid refrigerant into the circulation channel, and the other end of the circulation channel is a discharge for discharging the liquid refrigerant from the circulation channel. It is connected to the outlet 40b.

  The supply port 40a of the 1st liquid cooling heat sink 40 is connected to the discharge port 50b of the 2nd liquid cooling heat sink 50 via the heat insulation hose 41a. On the other hand, the discharge port 40b of the first liquid-cooled heat sink 40 is connected to the suction port 42a of the pump 42 via a heat insulating hose 41b. The discharge port 42 b of the pump 42 is connected to one end portion of the heat insulating hose 41 c, and the other end portion of the heat insulating hose 41 c is connected to the supply port 50 a of the second liquid cooling heat sink 50. Similar to the first liquid-cooled heat sink 40, the second liquid-cooled heat sink 50 has a circulation channel for circulating the liquid refrigerant connected to the supply port 50a and the discharge port 50b.

  The heat insulating hoses 41a, 41b, 41c are configured to include a heat insulating material composed of, for example, a silicone rubber tube and a polyethylene foam having a thickness of about 5 mm covering the outside of the silicone rubber tube, and the heat insulating hoses 41a, 41b, 41c Heat conduction from the outside to the liquid refrigerant flowing through is blocked. The diameters of the heat insulating hoses 41a, 41b and 41c are about 20 mm, which is smaller than the diameters of the heat insulating hoses 108a and 108b of the radiation detection apparatus 100 shown in FIG.

  The upper and lower surfaces of the second liquid-cooled heat sink 50 are heat absorption surfaces of the second Peltier elements 52a and 52b having a single stage through a heat transfer body 54 made of a metal having a relatively high thermal conductivity, respectively. Connected to (low temperature side). That is, the upper surface and the lower surface of the second liquid-cooled heat sink 50 are thermally connected to the heat absorbing surfaces of the second Peltier elements 52a and 52b. The heat absorbing surfaces of the second Peltier elements 52a and 52b are controlled by a controller (not shown) so as to maintain the surface of the second liquid-cooled heat sink 50 at a desired temperature (for example, −1 ° C.). The second liquid-cooled heat sink 50, the heat transfer body 54, and the second Peltier elements 52a and 52b are covered with a heat insulating material 56 made of urethane foam or the like, and heat conduction from the outside to these components is performed. It is designed to be blocked. In the present embodiment, the heat transfer surface 54 is provided between the second Peltier elements 52a and 52b and the second liquid-cooled heat sink 50, so that the heat generating surfaces of the second Peltier elements 52a and 52b are second liquid-cooled. It is kept away from the heat sink 50. Thereby, the influence with respect to the 2nd heat sink 50 of the radiant heat emitted from the heat generating surface of the 2nd Peltier elements 52a and 52b can be made small.

  Each heat generating surface (high temperature side) of the second Peltier elements 52 a and 52 b is connected to an air cooling heat sink 58. The air-cooled heat sink 58 has a plurality of protruding structures for efficiently radiating heat generated from the heat generating surfaces of the second Peltier elements 52a and 52b into the air. The cooling fan 59 is a fan for blowing air to cool the air-cooled heat sink 58 and is arranged to blow air to each of the air-cooled heat sinks 58 provided on the upper surface side and the lower surface side of the second liquid-cooled heat sink 50, respectively. ing. The second liquid cooling heat sink 50, the heat transfer body 54, the second Peltier elements 52 a and 52 b, the heat insulating material 56, the air cooling heat sink 58 and the cooling fan 59 constitute a cooling unit 60.

  The cooling fan 59 and the pump 42 are installed on the detector base 28 via a vibration isolating unit 29 configured by an elastic member such as rubber. Thereby, the propagation of the vibration generated by the cooling fan 59 and the pump 42 to the radiation detection element 10 is reduced.

  The first liquid-cooled heat sink 40 plays a role of keeping the temperature of the heat generating surface of the first Peltier element 30 constant. As a result, the temperature of the radiation detection element 10 is kept constant (−20 ° C. in the present embodiment), and continuous imaging of radiation images using the radiation detection element 10 becomes possible. The liquid refrigerant supplied to the first liquid-cooled heat sink 40 is supplied to the pump 42 via the heat insulating hose 41b. The liquid refrigerant discharged from the pump 42 is supplied to the circulation channel of the second liquid-cooled heat sink 50 via the heat insulating hose 41c. The liquid refrigerant is cooled by the second Peltier elements 52a and 52b having a single stage while flowing through the circulation flow path of the second liquid-cooled heat sink 50. The liquid refrigerant cooled by the second Peltier elements 52a and 52b is returned to the first liquid cooling heat sink 40 via the heat insulating hose 41b. Thus, the cooling device of the radiation detection apparatus 1 according to the present embodiment takes heat generated from the radiation detection element 10 into the liquid refrigerant in the first liquid-cooled heat sink 40 via the first Peltier element 30. In this configuration, the liquid refrigerant that has taken in heat is cooled in the cooling unit 60 including the second liquid-cooled heat sink 50 and returned to the first liquid-cooled heat sink 40. In addition, the structure except the radiation detection element 10 among the radiation detection apparatuses 1 which concern on embodiment of this invention becomes a cooling device which concerns on embodiment of this invention.

  FIG. 3 is a cross-sectional view of the heat insulating material 81 constituting the heat insulating cover 80. The heat insulating material 81 is a metal including a metal film (for example, an aluminum foil) having a heat shielding property (heat reflective property), for example, a core material 82 made of a porous material having a relatively low thermal conductivity such as urethane, powdered silica, and glass wool. It is a vacuum heat insulating material obtained by covering the interior with a laminating material 83 and then sealing the interior with a reduced pressure.

  FIG. 4A is a cross-sectional view showing a state of heat conduction in the heat insulating material 81. As shown in FIG. 4A, in the heat insulating material 81, the heat conduction through the vacuum-sealed core material 82 is almost completely cut off, and the heat conduction along the metal laminate material 83 covering the core material 82 is prevented. Become dominant. That is, the heat on the high temperature side of the heat insulating material 81 moves along the metal laminate material 83 and moves to the low temperature side via the end portion (seal portion) 84. FIG. 4B is a diagram illustrating the relationship between the distance X from the end portion 84 and the amount of heat Q transferred. As shown in FIG. 4B, the greater the distance X from the end portion 84 of the metal laminate 83, the greater the thermal resistance, and thus the lower the amount of heat Q transferred.

  Therefore, as shown in FIG. 5, two heat insulating materials 81A and 81B are overlapped to secure a distance L between the end portion 84A of the low temperature side heat insulating material 81A and the end portion 84B of the high temperature side heat insulating material 81B. Thus, the amount of heat transfer from the high temperature side to the low temperature side can be reduced. That is, the above distance L corresponds to the overlap length of the two heat insulating materials 81A and 81B, and higher insulation performance is exhibited by setting the overlap length according to the temperature difference between the high temperature side and the low temperature side. It becomes possible to make it. Based on the above, the heat insulation cover 80 was produced as follows using a heat insulating material.

  Fig.6 (a) is a perspective view which shows the preparation methods of the heat insulation cover 80 using several heat insulating materials 81a-81d, FIG.6 (b) is comprised combining these heat insulating materials 81a-81d. 3 is a top view of a heat insulating cover 80. FIG.

  Below, the method to produce the heat insulation cover 80 using the some heat insulating materials 81a-81d is demonstrated. First, rectangular heat insulating materials 81 a to 81 d having dimensions corresponding to the dimensions of each surface of the heat insulating cover 80 are prepared. Next, the heat insulating materials 81a to 81d are bent.

  The heat insulating material 81a is bent along two fold lines 91 parallel to the short side thereof so as to have a U-shape. The surface S1 formed by the bending process forms the upper surface of the heat insulating cover 80, and the surface S2 and the surface S3 form two side surfaces of the heat insulating cover 80 that face each other.

  The rectangular heat insulating material 81b is bent along two fold lines 92 parallel to the short side thereof so as to have a U-shape. The surface S4 formed by this bending process forms the upper surface of the heat insulating cover 80, and the surfaces S5 and S6 have two side surfaces adjacent to each other adjacent to the side surface of the heat insulating cover 80 formed by the heat insulating material 81a. Form.

  The heat insulating material 81c is bent along two fold lines 93 parallel to the short side thereof so as to have a U-shape. The surface S7 formed by the bending process forms a side surface of the heat insulating cover 80, and the surface S8 and the surface S9 form a side surface adjacent to the side surface of the heat insulating cover 80 formed by the surface S7.

  The heat insulating material 81d is bent along two fold lines 94 parallel to the short side thereof so as to have a U-shape. The surface S10 formed by this bending process forms the side surface of the heat insulating cover 80, and the surface S11 and the surface S12 form a side surface adjacent to the side surface of the heat insulating cover 80 formed by the surface S10.

  Next, the heat insulating materials 81a and 81b, which are bent so that the surface S1 and the surface S4 overlap and the surfaces S2 and S3, the surface S5, and the surface S6 are adjacent to each other, are overlapped. Next, the heat insulating material 81c is further overlapped so that the surface S2 and the surface S7 overlap, the surface S5 and the surface S8 overlap, and the surface S6 and the surface S9 overlap. The end portions in the longitudinal direction of the heat insulating material 81c are respectively disposed at the central portion of the surface S5 and the central portion of the surface S6 of the heat insulating material 81b. Next, the heat insulating material 81d is further overlapped so that the surface S3 and the surface 10 overlap, the surface S5 and the surface S11 overlap, and the surface S6 and the surface S12 overlap. The end portions in the longitudinal direction of the heat insulating material 81d are respectively disposed at the central portion of the surface S5 and the central portion of the surface S6 of the heat insulating material 81b. In this manner, the heat insulating cover 80 is completed by superimposing the heat insulating materials 81a to 81d.

  As described above, by bending a single heat insulating member to form a plurality of surfaces in the heat insulating cover 80, it is possible to reduce the number of end portions 84 of the heat insulating material serving as a heat transfer path. . Further, by superimposing the respective heat insulating materials 81a to 81d subjected to the bending process as described above, all the surfaces of the heat insulating cover 80 have a laminated structure of two heat insulating materials and are arranged on the outer side (high temperature side). It is possible to separate the end portion of the heat insulating material and the end portion of the heat insulating material disposed on the inner side (low temperature side). Thereby, since the thermal resistance between the edge parts of a heat insulating material can be enlarged, it becomes possible to make small the heat transfer amount Q between the said edge parts, and can show the high heat insulation performance in the heat insulation cover 80. . Further, since the heat insulating cover 80 according to the present embodiment is configured to include the metal laminate material 83 having a heat shielding property (heat reflecting property), the temperature detection of the radiation detecting element 10 due to radiation as well as heat conduction is prevented. Is possible.

  FIG. 7 shows the temperature and power consumption of each part when the temperature of the bottom surface of the radiation detection element 10 is maintained at −20 ° C. in the radiation detection apparatus 1 according to the present embodiment. When the temperature of the bottom surface of the radiation detection element 10 is maintained at −20 ° C., the temperature of the heat generating surface (high temperature side) of the first Peltier element 30 is maintained at about 10 ° C. by the first liquid cooling heat sink 40. At this time, the temperature of the liquid refrigerant discharged from the first liquid-cooled heat sink 40 and flowing through the heat insulating hose 41b is about 6 ° C., and the temperature of the liquid refrigerant discharged from the pump 42 and flowing through the heat insulating hose 41c is about 7 ° C. is there. The liquid refrigerant discharged from the pump 42 is cooled to about 4 ° C. by the second Peltier elements 52 a and 52 b while flowing through the circulation flow path in the second liquid cooling heat sink 50. At this time, the temperature of the endothermic surfaces (low temperature side) of the second Peltier elements 52a and 52b is set to about −1 ° C. The liquid refrigerant at about 4 ° C. discharged from the second liquid-cooled heat sink 50 is returned to the first liquid-cooled heat sink 40 via the heat insulating hose 41a.

  In the above case, the power consumption of the radiation detection element 10 is about 3 W, the power consumption of the first Peltier element 30 is about 24 W, the power consumption of the second Peltier elements 52 a and 52 b is about 84 W, and the power consumption of the pump 42. Is about 2 W, and the total power consumption in the radiation detection apparatus 1 is about 197 W.

  As is clear from the above description, in the cooling device according to the embodiment of the present invention and the radiation detection device 1 including the cooling device, a Peltier element type is used instead of the low-temperature circulating water tank 110 in the radiation detection device 100 shown in FIG. Since the cooling unit 60 is used to cool the liquid refrigerant, the apparatus can be reduced in weight, size, and power consumption.

  In addition, according to the cooling device and the radiation detection device 1 including the cooling device according to the present embodiment, the radiation detection device shown in FIG. It becomes possible to shorten significantly than 100. For example, the temperature of the radiation detection element 10 can be maintained at −20 ° C. in about 15 minutes after the power is turned on.

  FIG. 8 is a diagram illustrating a configuration of a radiation detection apparatus 2 according to a comparative example in which a liquid refrigerant is cooled using a Peltier element type cooling unit, similarly to the radiation detection apparatus 1 according to the embodiment of the present invention. Below, the radiation inspection apparatus 2 which concerns on a comparative example demonstrates the part different from the radiation detection apparatus 1 which concerns on embodiment of this invention.

  In the radiation detection apparatus 1 according to the embodiment of the present invention, the radiation detection element 10 is cooled by the first Peltier element 30 having a single stage configuration, whereas in the radiation detection apparatus 2 according to the comparative example, the radiation detection element 10 is cooled. Is cooled by the first liquid-cooled heat sink 140. The liquid refrigerant circulating in the first liquid-cooled heat sink 140 is supplied to the second liquid-cooled heat sink 150 constituting the cooling unit 160 via the heat insulating hose 141b, the pump 42, and the heat insulating hose 141c.

  In the radiation detection apparatus 1 according to the embodiment of the present invention, the liquid refrigerant circulating in the second liquid-cooled heat sink 50 is cooled by the second Peltier elements 52a and 52b having a single-stage configuration, but is compared. The liquid refrigerant circulating in the second liquid-cooled heat sink 150 according to the example is cooled by the two-stage Peltier elements 152a and 152b. Since the Peltier elements 152a and 152b have a two-stage configuration, the amount of heat generated on the heat generation surface of the Peltier elements 152a and 152a is larger than that in the case of the one-stage configuration. The air-cooling heat sink 158 and the cooling fan 159 connected to are larger in size than the air-cooling heat sink 58 and the cooling fan 59 in the radiation detection apparatus 1 according to the embodiment of the present invention. The liquid refrigerant cooled by the Peltier elements 152a and 152b is returned to the first liquid cooling heat sink 140 via the heat insulating hose 141a.

  As described above, the cooling device for the radiation detection apparatus 2 according to the comparative example directly takes in the heat generated from the radiation detection element 10 into the liquid refrigerant in the first liquid-cooled heat sink 140 without passing through the Peltier element. In this configuration, the liquid refrigerant is cooled in the cooling unit 160 including the second liquid-cooled heat sink 150 and returned to the first liquid-cooled heat sink 140.

  FIG. 8 shows the temperature and power consumption of each part when the temperature of the bottom surface of the radiation detection element 10 is maintained at −20 ° C. In the radiation detection apparatus 2 according to the comparative example, when the temperature of the bottom surface of the radiation detection element 10 is maintained at −20 ° C., the temperature of the liquid refrigerant discharged from the first liquid-cooled heat sink 140 and flowing through the heat insulating hose 141b is about − The temperature of the liquid refrigerant discharged from the pump 42 and flowing through the heat insulating hose 141c is about −19 ° C. The liquid refrigerant discharged from the pump 42 is cooled to about −23 ° C. by the two-stage Peltier elements 152 a and 152 b while flowing through the circulation flow path in the second liquid cooling heat sink 150. At this time, the temperature of the endothermic surfaces (low temperature side) of the Peltier elements 152a and 152b is set to about −30 ° C. The liquid refrigerant at about −23 ° C. discharged from the second liquid-cooled heat sink 150 is returned to the first liquid-cooled heat sink 140 via the heat insulating hose 141a.

  In the above case, the power consumption in the radiation detection element 10 is about 3 W, the power consumption in the two-stage Peltier elements 152 a and 152 b is about 125 W, and the power consumption in the pump 42 is about 2 W. The radiation detection according to the comparative example The total power consumption in the device 2 is about 255W.

  Thus, in the configuration in which the heat from the radiation detection element 10 is directly taken into the liquid refrigerant by the first liquid-cooled heat sink 140 disposed immediately below the radiation detection element 10, the temperature of the bottom surface of the radiation detection element 10 is −20. When it is going to maintain at ° C., the temperature of the liquid refrigerant flowing in the heat insulating hoses 141a, 141b, 141c is about −20 ° C. Therefore, sufficient countermeasures against dew condensation are required in the heat insulating hoses 141a, 141b, and 141c, and the thickness of the heat insulating material that constitutes the heat insulating hoses 141a, 141b, and 141c is the same as that of the radiation detection apparatus 100 (see FIG. 1) that uses a low temperature circulating water tank. The thickness needs to be about 30 mm. As a result, the diameters of the heat insulating hoses 141a, 141b, and 141c are about 70 mm. That is, according to the configuration of the radiation detection apparatus 2 according to the comparative example, the radiation detection apparatus 100 (see FIG. 1) using the low-temperature circulating water tank can be miniaturized by adopting the Peltier element type cooling unit 160. Although possible, it is impossible to reduce the diameter of the heat insulating hoses 141a, 141b, and 141c, and a sufficient size reduction cannot be achieved. Further, since the diameter of the heat insulating hoses 141a, 141b, and 141c cannot be reduced, the propagation of vibration from the pump 42 and the cooling fan 159 through the heat insulating hoses 141a, 141b, and 141c cannot solve the problem. .

  On the other hand, according to the radiation detection apparatus 1 according to the present invention, when the temperature of the bottom surface of the radiation detection element 10 is to be maintained at −20 ° C., the temperature of the liquid refrigerant flowing in the heat insulating hoses 41a, 41b, 41c is 4 The temperature is set to from 7 to 7 ° C. That is, the temperature of the liquid refrigerant flowing in the heat insulating hoses 41a, 41b, and 41c is closer to the ambient temperature than the radiation detection device 2 according to the comparative example, so the thickness of the heat insulating material that constitutes the heat insulating hoses 41a, 41b, and 41c is reduced. It is possible to reduce the diameter of the heat insulating hoses 41a, 41b, 41c. In this embodiment, the thickness of the heat insulating material constituting the heat insulating hoses 41a, 41b, 41c is about 5 mm, and the diameter of the heat insulating hoses 41a, 41b, 41c is about 20 mm. Therefore, according to the radiation detection apparatus 1 which concerns on embodiment of this invention, it becomes possible to comprise further smaller than the radiation detection apparatus 2 which concerns on a comparative example. Further, since the diameters of the heat insulating hoses 41a, 41b, and 41c are reduced, it becomes possible to suppress propagation of vibrations from the pump 42 and the cooling fan 59 via the heat insulating hoses 41a, 41b, and 41c, and radiation with good image quality. Images can be acquired.

  Further, in the radiation detection apparatus 2 according to the comparative example, when the temperature of the bottom surface of the radiation detection element 10 is to be maintained at −20 ° C., the endothermic surfaces (low temperature side) of the Peltier elements 152 a and 152 b that constitute the cooling unit 160. The temperature is −30 ° C., and the temperature of the heat generating surface (high temperature side) is the ambient temperature (for example, 22 ° C.). That is, since the temperature difference between the heat absorption surface and the heat generation surface of the Peltier elements 152a and 152b is 50 ° C. or more, each of the Peltier elements 152a and 152b needs to have a two-stage configuration. As a result, the power consumption in the Peltier elements 152a and 152b is 250W.

  On the other hand, according to the radiation detection apparatus 1 according to the present invention, when the temperature of the bottom surface of the radiation detection element 10 is to be maintained at −20 ° C., the endothermic surfaces of the second Peltier elements 52 a and 52 b constituting the cooling unit 60. The temperature of the (low temperature side) is set to −1 ° C., and the temperature of the heat generating surface (high temperature side) is set to the ambient temperature (22 ° C.). That is, since the temperature difference between the heat absorption surface and the heat generation surface of the second Peltier elements 52a and 52b is 23 ° C., each of the second Peltier elements 52a and 52b can be configured in one stage. As a result, the power consumption in the second Peltier elements 52a and 52b can be 168W. In the radiation detection apparatus 1 according to the present embodiment, the first Peltier element 30 disposed immediately below the radiation detection element 10 is further required, but the second Peltier elements 52a and 52b are each configured in one stage. Therefore, the power consumption of the entire apparatus can be made smaller than that of the radiation detection apparatus 2 according to the comparative example.

  Further, since the heat generation amount at the heat generation surface of the second Peltier elements 52a and 52a according to the embodiment of the present invention is smaller than that of the two-stage Peltier elements 152a and 152b according to the comparative example, the air cooling heat sink 58 and the cooling fan 59 can be made smaller than the air-cooled heat sink 158 and the cooling fan 159 according to the comparative example.

  Further, in the radiation detection apparatus 1 according to the embodiment of the present invention, since the outside of the sealed container 20 is covered with the heat insulating cover 80 made of a vacuum heat insulating material, the heat intrusion into the sealed container 20 can be reduced. it can. Since the heat insulating cover 80 is composed of a vacuum heat insulating material obtained by covering the core material 82 with a metal laminate material 83 having a heat shielding property (heat reflecting property) and then reducing the inside to seal it, And the temperature rise of the radiation detection element 10 by radiation can be prevented. In this way, by insulating the radiation detection element 10 to be cooled using the heat insulating cover 80 made of a vacuum heat insulating material, the cooling efficiency can be increased, so that further power saving can be achieved. .

DESCRIPTION OF SYMBOLS 1 Radiation detection apparatus 10 Radiation detection element 13 Heat sink heat transfer body 20 Sealed container 30 1st Peltier element 30
First liquid-cooled heat sink 40
41a Thermal insulation hose 41a
41b Insulation hose 41b
41c heat insulation hose 41c
42 Pump 50 Second liquid-cooled heat sink 50
52a, 52b Second Peltier element 81 Insulating material 81
82 Core 82
83 Metal laminate 83

Claims (9)

A heat transfer body having a cooling surface thermally connectable to the surface to be cooled of the object to be cooled;
A first Peltier element having a heat absorption surface thermally connected to a surface of the heat transfer body opposite to the cooling surface;
A first liquid-cooled heat sink thermally connected to the heat generating surface of the first Peltier element and having a flow path for circulating a refrigerant therein;
A second liquid-cooled heat sink having a flow path connected to the flow path of the first liquid-cooled heat sink,
A second Peltier element having an endothermic surface thermally connected to the second liquid-cooled heat sink;
A circulation mechanism for circulating a refrigerant between the first liquid-cooled heat sink and the second liquid-cooled heat sink;
Including cooling system.   The cooling device according to claim 1, further comprising a heat insulating cover that is provided so as to cover the cooling object and blocks heat conduction and heat radiation to the cooling object.   The cooling device according to claim 1 or 2, further comprising a heat insulating material provided so as to be in contact with the surface to be cooled and covering the heat transfer body so as to expose the cooling surface of the heat transfer body.   The cooling device according to any one of claims 1 to 3, wherein the first Peltier element and the second Peltier element have a one-stage configuration.   The said heat insulation cover is comprised including the vacuum heat insulating material obtained by coat | covering the core material with low heat conductivity with the film which has heat insulation, and reducing the inside and sealing. The cooling device according to any one of the above.   The heat insulating cover is composed of a plurality of vacuum heat insulating materials that are bent so as to form a plurality of surfaces each corresponding to each surface of the heat insulating cover, and each surface of the heat insulating cover includes a plurality of vacuums. The cooling device according to claim 5, which has a laminated structure in which heat insulating materials are laminated. The circulation mechanism includes a heat insulating hose having flexibility connected to the flow path of the first liquid-cooled heat sink and the flow path of the second liquid-cooled heat sink;
The cooling mechanism of any one of Claims 1 thru | or 6 including the pump connected with the said heat insulation hose.   The cooling mechanism according to claim 2, further comprising an airtight container that is provided inside the heat insulating cover and accommodates the object to be cooled.   The radiation detection apparatus containing the cooling device of any one of Claims 1 thru | or 8 which contain the radiation detection element thermally connected to the heat absorption surface of the said 1st Peltier element as said cooling target object.

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