High voltage generator, two-phase cooling system therefor and X-ray radiator

Abstract

The present invention relates to a two-phase cooling system for an X-ray high voltage generator, an X-ray high voltage generator, an X-ray radiator and a computer tomography device. The two-phase cooling system for an X-ray high voltage generator comprises: a cooling block, wherein the cooling block spatially surrounds a cooling channel loop, wherein the cooling channel loop is at least partially filled with a working medium and acts as an oscillating heat pipe, and a radiator for dissipating heat from a heat source, characterized in that the cooling block is composed of a material having a polymer.

Description

Technical Field

[0001] The invention relates to a two-phase cooling system for an X-ray high voltage generator, an X-ray high voltage generator, an X-ray radiator and a computer tomography device. Background Art

[0002] Conventional X-ray high voltage generators are usually used to generate high voltages in the kV range from the usual grid voltage. For example, this high voltage is applied between an electron emitter and the anode of an X-ray tube, wherein the electrons emitted by the electron emitter are accelerated to a kinetic energy in the keV range by means of the high voltage and generate X-rays in interaction with the anode.

[0003] Such an X-ray high voltage generator outputs a relatively high peak electrical power to the X-ray tube during the time when the X-rays are generated. Depending on the corresponding application, the peak electrical power is in the range of several kW. In the time period between the generation of X-rays, the X-ray high voltage generator usually does not output power or only outputs a very low average electrical power. In other words, the X-ray high voltage generator is usually set up to provide high peak power when the average power output is low.

[0004] This configuration of the X-ray high voltage generator places high demands on the cooling system of the X-ray high voltage generator. Because during the output of peak electrical power, a correspondingly high power loss is usually generated in the X-ray high voltage generator. In order to prevent the power electronic circuit components provided in the X-ray high voltage generator for providing high voltage from overheating, the power loss converted into heat must be at least partially, preferably completely, discharged through the cooling system.

[0005] Another challenge is that the power electronic components that are regularly operated in parallel in the X-ray high-voltage generator are preferably connected as evenly as possible to the heat sink of the cooling system. In this case, the heat must be transported in sections of different lengths. The circuit components of the X-ray high voltage generator usually determine the performance of the entire X-ray high voltage generator in this case, for example, due to the maximum distance from the heat sink of the cooling system.

[0006] For example, the size of a conventional cooling system can be determined so that the maximum power loss introduction can be permanently derived. It is known that the cooling system of a conventional X-ray high-voltage generator is accordingly equipped with an intermediate heat storage device so that the heat loss can be temporarily stored in the intermediate heat storage device through the heat capacity formed thereby. For example, the power level of the cooling system can be set by the specific design of the intermediate heat storage device. Such an intermediate heat storage device is preferably arranged near a heat source, especially a power electronic component. For example, an intermediate storage block with a high heat capacity, for example made of copper and / or aluminum, is suitable as an intermediate heat storage device. The intermediate heat storage device is usually connected to the heat source via as little heat conversion as possible. Due to the heat capacity of the intermediate heat storage device, preferably, the power loss introduction that occurs during the generation of X-rays can be stored in the intermediate storage device, and then the heat energy cached in the intermediate heat storage device is usually output to an external cooling medium with a higher time constant. For this purpose, the power loss is output to a heat sink, for example, via a carrier plate, which can form the frame of a computed tomography device, for example.

[0007] Such conventional cooling systems with intermediate heat storage have a relatively complex structure, which can consist of a plurality of elements, such as fixing metal plates, intermediate storage blocks and power electronics components. As a result, conventional cooling systems are usually relatively large and / or heavy, which can be cost-intensive due to the use of materials. The narrow, in particular mutually dependent production tolerances also place high demands on the cooling system and its installation process. Summary of the invention

[0008] The present invention is based on the object of providing a two-phase cooling system for an X-ray high voltage generator, an X-ray high voltage generator, an X-ray radiator and a computer tomography device having a more flexible and efficient cooling system.

[0009] The object is achieved by the features of the exemplary embodiments. Advantageous embodiments are described in the following description.

[0010] Two-phase cooling system for X-ray high voltage generators with:

[0011] a cooling block, wherein the cooling block spatially surrounds a cooling channel circuit, wherein the cooling channel circuit is at least partially filled with a working medium and acts as an oscillating heat pipe, and

[0012] - a heat sink for dissipating heat from a heat source,

[0013] It is characterized in that

[0014] The cooling block consists of a material comprising a polymer.

[0015] The two-phase cooling system achieves the following advantages in particular:

[0016] Advantageously, by using a two-phase cooling system, a spatial decoupling of the heat sink and the heat source can be achieved, whereby, for example, the structure of an X-ray high voltage generator becomes more flexible. In particular, the design of a cooling block made of a polymer with a built-in cooling channel loop makes it possible to overcome the large distance between the heat source and the heat sink, typically without affecting the cooling power of the two-phase cooling system. In other words, the two-phase cooling system, in particular the cooling channel loop and the cooling block, achieves spatial flexibility, because, in contrast to conventional two-phase cooling systems, it is now advantageously possible to directly thermally couple a heat sink that is far away. Advantageously, spatial flexibility alternatively or additionally achieves more flexible shaping when designing the two-phase cooling system, in particular the outer shape of the cooling block.

[0017] Another advantage of the two-phase cooling system relates to the feasibility of being able to integrate different functions in the two-phase cooling system, especially in the cooling body block composed of a material having a polymer. These functions include, for example, electrical insulation, distance compensation, housing (part), interface function and / or shielding in addition to heat dissipation. This advantageously saves at least one other common component, which is usually required for these functions. Integrating these functions or a part thereof into the two-phase cooling system can also simplify and / or shorten the production process of the X-ray high-voltage generator, because a small number of traditional components must usually be installed. This is usually accompanied by cost advantages. Distance compensation can be achieved by customized shaping of the cooling body block. The housing function can be achieved in the following manner: the housing and the cooling body block are produced in one step. Compared with traditional metal plates, simpler integration feasibility is usually obtained due to the producibility by means of injection molding or 3D printing. The shielding function can be achieved in particular by at least partially coating the cooling body block, for example, by means of a fluid-tight, especially shielding or conductive layer, or by means of a metal element. The interface function can preferably be realized by introducing current guides into the cooling block, such as busbars for high currents, holding devices and / or fixing elements. The advantage of using a two-phase cooling system in an X-ray high-voltage generator is that in principle, a two-phase cooling system functions properly in a vacuum.

[0018] The two-phase cooling system comprises a radiator and / or acts as a radiator. The radiator is particularly suitable for discharging a part of the power loss input converted into heat. The radiator usually dissipates more power loss to the environment outside the two-phase cooling system than the radiator absorbs from the environment. The radiator is at least one partial area of ​​the two-phase cooling system, which is suitable for heat dissipation, for example due to material composition, internal structure and / or external shape. The external shape of the radiator can have a surface increase, such as by cooling fins or cooling fins. The radiator can be a passive component or an active component, for example a component equipped with a fan. The radiator can be operated actively or passively. The radiator can be connected to a cooling block and / or directly thermally coupled to the cooling block.

[0019] The radiator is usually away from the heat source so that the transferred heat is discharged away from the heat source. The heat dissipation of the heat source includes in particular the cooling of the heat source. For example, the radiator is directly thermally coupled to a gaseous or liquid external cooling circuit to enhance the heat dissipation. In this case, in particular, the external cooling circuit forms the surrounding environment of the radiator, and the radiator usually acts as a heat exchanger for the external cooling circuit. The external cooling circuit can be formed in particular by an electrically insulating fluid, in particular oil, in which the two-phase cooling system, the X-ray high voltage generator, the circuit device and / or at least one power electronic circuit component are installed. The heat transfer in the external cooling circuit can be based on forced convection.

[0020] The two-phase cooling system can be designed in particular for dissipating heat for other electronic components and / or power electronic circuit components. The two-phase cooling system can be designed in particular for dissipating heat from one heat source at one heat sink, dissipating heat from multiple heat sources at one heat sink, dissipating heat from one heat source at multiple heat sinks, or dissipating heat from multiple heat sources at multiple heat sinks.

[0021] Direct thermal coupling, thermal direct coupling or thermal coupling means in particular that two elements are physically connected to one another for heat transfer. For example, at least one power electronics component can be connected to a two-phase cooling system, in particular is connected to or is connected to a two-phase cooling system.

[0022] A cooling channel circuit is provided in the cooling block. The cooling block usually completely surrounds the cooling channel circuit, so that the working medium is substantially confined in the cooling channel circuit by the channel walls of the cooling channel circuit. Substantially means that, depending on the material composition of the cooling block and / or a certain porosity of the cooling block, a certain diffusion of the working medium through the channel walls, usually a small diffusion, may occur.

[0023] The cooling block can be formed in one piece or in multiple pieces. A one-piece cooling block usually consists of one block or is monolithic. A multi-piece cooling block can be formed from a plurality of cooling block elements, which are assembled to form the cooling block. A plurality of cooling block elements can be dimensioned differently and / or usually have the same material composition. For example, it is conceivable that one cooling block element surrounds a cooling channel loop and another cooling block element surrounds another cooling channel loop or does not surround the cooling channel loop. If the other cooling block element does not surround the cooling channel loop, the cooling block element can be used in particular as a top cover, for example a top cover for a heat source or a cooling body extension.

[0024] The cooling block element can in principle be formed as part of a housing, in particular as part of an X-ray high voltage generator. In this case, for example, the surface opposite the at least one power electronics component usually forms a heat sink. Another advantage of the cooling block can be that a holding device for metal components such as a printed circuit board, a fastening element and / or for a current supply is provided as part of the cooling block.

[0025] The cooling channel loop comprises a complete path along which the working medium moves back and forth, in particular oscillates, during operation. In the present application, the cooling channel loop is used as an oscillating heat pipe. In this case, the term "pulse" can be used instead of "oscillation". In particular, the cooling channel loop has a plurality of straight and / or curved channel segments. The channel segments can be arranged in a circular, meandering, spiral, planar, elongated and / or angular shape. In particular, the number of channel segments per unit area can be increased in the region of a radiator and / or a heat source.

[0026] For example, the diameter of the channel section is less than 6 mm, preferably less than 3 mm. The cross section of the channel section is, for example, 0.1 mm. 2 Up to 50mm 2 Between, preferably 0.25mm 2 Up to 4mm 2 The channel section is usually designed to achieve a capillary flow or capillary behavior, especially when the heat pipe is designed as an oscillating heat pipe. Due to the surface tension that prevails here, the gas phase and the liquid phase separate from each other. The channel section usually has a closed, for example tubular, especially circular or (rectangular) cross section. During operation, the working medium oscillates back and forth in the cooling channel circuit. Usually, the working medium can have a preferred flow direction.

[0027] A two-phase cooling system is characterized in that the cooling channel circuit has a first section facing the heat source and a second section facing the radiator. At the first section, the cooling channel circuit usually absorbs at least a part of the power loss introduced and transfers at least a part of the power loss introduced to the radiator at the second section. For example, the working medium evaporates at the first section (also called evaporator) and condenses at the second section (also called condenser). That is, the heat transfer is carried out in particular by phase change in the case of a repetitive change between gas phase and liquid phase. Oscillating heat pipes use phase change and convection heat transfer.

[0028] Regarding the principle functional mode and design scheme of (oscillating) heat pipes, reference is made to Taft's publication "Non-Condensable Gases and Oscillating Heat Pipe Operation" (Frontiers in Heat Pipes (FPH), 4, 013003 (2013), DOI: 10.5098 / fhp.v4.1.3003), Yang et al.'s "A novel flat polymer heat pipe with thermal via for cooling electronic devices" (Energy Conversion and Management 100 (2015) 37-44, DOI: 10.1016 / j.enconman.2015.04.063), Schwarz et al.'s "Interaction of flow pattern and heat transfer in oscillating heat pipes for hot spot applications" (Applied Thermal Engineering Volume 196, September (2021), 117334, DOI: https: / / doi.org / 10.1016 / j.applthermaleng.2021.117334 ), Schwarz et al., "Thermodynamic Analysis of the Dryout Limit of Oscillating HeatPipes" (Energies 13, No. 23: 6346. https: / / doi.org / 10.3390 / en13236346), "Characterization of polypropylene pulsating heat stripes: Effects of orientation, heat transfer fluid, and loop geometry" by Der et al. (Applied ThermalEngineering 184(2021)116304, DOI: 10.1016 / j.applthermaleng.2020.116304) and "Thermal performance of pulsating heat" by Der et al. stripes(PHS)built with plasticmaterials” (Joint 19 th IHPC and 13 th IHPS, Pisa, Italy, 10-14 June 2018).

[0029] The cooling channel loop can be partially filled with a working fluid. The filling degree of the cooling channel loop is generally between 10% and 90%, preferably between 30% and 80%. The filling degree is defined according to the proportion of the working medium present in a liquid state relative to the volume. In particular, during operation, the remaining part of the volume is filled with a gaseous working medium. The cooling channel loop can have a closable opening for adjusting the filling degree of the working medium. The cooling channel loop is preferably sealed and / or irreversibly closed or closable. In particular, after filling the cooling channel loop, the cooling channel loop can be closed. For example, the opening of the cooling channel loop can be closed by brazing, welding, screwing and / or melting. The working medium in the cooling channel loop is especially a liquid, and the liquid is preferably a dielectric, especially an electrical insulation. The working fluid can be acetone, ethanol, water, methanol, a fluoride such as Novec, perfluorohexane such as FC-72, a solvent, a coolant or a combination of the above substances.

[0030] According to the invention, the part of the cooling block that is in contact with the working medium or the entire cooling block is constructed from an electrically insulating material, for example from or with a polymer. Preferably, that is to say, the two-phase cooling system can advantageously ensure electrical insulation between the heat source and the heat sink, for which additional components are usually required in conventional cooling systems, in particular when using copper cooling blocks and / or aluminum cooling blocks.

[0031] That is to say, the cooling block of the two-phase cooling system is made of a material having a polymer. In other words, the cooling block has a polymer. In principle, it is conceivable that the material constituting the two-phase cooling system, for example, additionally has metal and / or ceramic, preferably without damaging these properties when constructed with a polymer, especially for the possibility of electrical insulation. Compared with metal, such a polymer cooling block especially provides the advantages of lower cost, lighter weight and / or simpler processing. In addition, the polymer is advantageously electrically insulating and / or non-magnetic. Polymers are generally not fluid-tight, especially not airtight. The cooling block is advantageously protected from gas, especially O2, CO2 and / or H2O intrusion, for example by means of a fluid-tight layer. The cooling block can be manufactured by additive manufacturing and / or injection molding manufacturing methods.

[0032] Advantageously, the cooling power of the working medium circulating in the cooling channel loop during operation is greater than the cooling power of the cooling block surrounding the cooling channel loop. In other words, the two-phase cooling system is designed so that the heat transfer in the cooling channel loop in the cooling block preferably greatly exceeds the heat conduction of the cooling block.

[0033] One embodiment provides that the polymer is polypropylene, polycarbonate, polyetheretherketone, polyamide or acrylonitrile-butadiene-styrene copolymer.

[0034] One embodiment provides that the material contains only polymers. In other words, the material consists only of polymers. In this case, the cooling block is a polymer cooling block.

[0035] An alternative embodiment to this provides that the material additionally contains metal and / or ceramic and that the material is homogenized by mixing. The ceramic can be composed in particular of Al2O3, Si3N or AlN. The metal can be copper, aluminum, iron or an alloy composed of these elements. For example, particles of different elements, i.e. polymer particles and metal particles and / or ceramic particles, are mixed with one another to form the material of the cooling block.

[0036] Ceramics, like glass and metals, are generally gas-tight materials. Depending on the gas, a certain thickness of the ceramic is required so that the ceramic is gas-tight. Thicknesses in the range below 100 nm are generally insufficient, so that the ceramic generally only delays gas diffusion. A thickness equal to or greater than 1 μm generally ensures that the ceramic and / or glass and / or metal is gas-tight and therefore fluid-tight.

[0037] One embodiment proposes that the cooling block has an insert, in particular an insert made of copper and / or aluminum, wherein the material of the insert has a higher thermal conductivity than the material of the cooling block. The insert can be dense or porous. For example, the insert can be completely or partially surrounded by the cooling block. Alternatively, the insert can be placed on the cooling block. Advantageously, the insert enables better thermal coupling between different components, in particular between the radiator, the heat source, the cooling block and / or the cooling channel loop. In principle, it is conceivable that the cooling block has a plurality of inserts, or that the insert is composed of a plurality of insert elements, in particular of the same structure.

[0038] It is conceivable that the cooling body block has another cooling channel loop, and the cooling channel loop and the other cooling channel loop are directly thermally coupled by means of an insert. The cooling channel loop and the other cooling channel loop can be realized in the same manner in principle, for example, by the same channel section structure. In principle, it is conceivable that the properties of the channel sections of the cooling channel loop and the other cooling channel loop, such as cross-section, working medium, arrangement, etc., are different. The working medium of the cooling channel loop and the working medium of the other cooling channel loop are particularly separated from each other, for example, by inserts and optionally additionally separated from each other by channel walls. That is to say, the corresponding closed paths are usually not crossed, so that the corresponding working media are not mixed. Due to direct thermal coupling, the insert advantageously realizes heat transfer from the cooling channel loop to the other cooling channel loop, and vice versa. In this design, the heat source is usually toward the cooling channel loop, and the radiator is toward the other cooling channel loop. In particular, the insert is arranged between the channel section of the cooling channel loop and the channel section of the other cooling channel loop.

[0039] The following improved form is feasible: the cooling channel loop and another cooling channel loop are respectively located in different geometric planes, wherein the planes have a spacing greater than zero, and at least one extension of the insert is related to the magnitude of the spacing, so as to thermally bridge the spacing between the cooling channel loop and another cooling channel loop, wherein the cooling channel loop and another cooling channel loop are directly thermally coupled by means of the insert. The two planes are particularly oriented parallel to each other. The two planes are particularly unfolded by the corresponding channel sections of the cooling channel loop. The embodiment advantageously realizes the structure of the two-phase cooling system on multiple planes and / or in multiple layers, wherein the corresponding cooling channel loop is directly thermally coupled by means of the insert and optionally by means of other inserts. That is to say, the embodiment provides the following advantages: it is possible to reduce, preferably eliminate the influence of gravity or centrifugal force on the working medium and the cooling power limitation associated therewith. For this reason, it can be particularly advantageous to orient at least one plane, especially the plane, tangentially and / or vertically to the direction of gravity and / or the direction of centrifugal force. For example, by using a two-phase cooling system on the rotating part of the gantry of a computed tomography apparatus, a centrifugal force may be generated, for example, greater than 5 g and less than 200 g, in particular between 50 g and 150 g, typically about 100 g.

[0040] In principle, it is conceivable that the two-phase cooling system has an auxiliary element for starting the two-phase cooling system, in particular an oscillating heat pipe. The following five variants each describe such an auxiliary element, which, taken individually or in any combination, is respectively suitable for improving the start-up of the two-phase cooling system. This improvement can be to increase the probability of starting the two-phase cooling system.

[0041] In particular, starting the two-phase cooling system includes starting the oscillating heat pipe and / or means that the working medium flows in the cooling channel loop. In the present application, the operation of the two-phase cooling system is defined as the flow of the working medium. Therefore, the two-phase cooling system is ready to dissipate heat. In other words, once the startup process begins, the two-phase cooling system dissipates heat. In order to start, the two-phase cooling system usually has to absorb heat. Here, the heat dissipation, especially the cooling effect, begins regularly. In particular, once there is a temperature difference between the heat source and the radiator, the startup is performed. Before the X-ray high-voltage generator is operated, the two-phase cooling system can in principle not be operated, which means that the working medium does not flow in the cooling channel loop during this period. Preferably, the two-phase cooling system is started before or once at least one power electronic circuit component forms a heat source.

[0042] A first variant proposes that the insert is arranged in the cooling channel circuit and is circulated by the working liquid and serves as an auxiliary element for starting the two-phase cooling system. In this embodiment, the insert can be dense or porous, for example a metal foam. In particular, the insert is arranged adjacent to the heat source and / or the radiator. Adjacent means, in particular, that the insert can enhance the direct thermal coupling due to the small distance from the heat source or the radiator.

[0043] A second variant provides that the two-phase cooling system has a liquid reservoir as an auxiliary element with an additional amount of working medium, wherein the liquid reservoir is connected to the cooling channel circuit. The liquid reservoir can be arranged in the cooling block. The liquid reservoir is usually arranged adjacent to the cooling channel circuit. The additional amount of working liquid preferably assists the start-up of the two-phase cooling system.

[0044] A third variant provides that the cooling channel circuit surrounds the element for surface enlargement, such as a helical spring and / or cooling fins as an auxiliary element. The element for surface enlargement preferably enhances the direct thermal coupling in situ and thus assists the start-up of the two-phase cooling system.

[0045] A fourth variant provides that the cooling channel loop has a tapered cross section adjacent to the heat source as an auxiliary element. In other words, the cooling channel loop tapers adjacent to the heat source. In principle, the cooling channel loop can alternatively or additionally taper adjacent to the radiator. The tapering of the cooling channel loop advantageously enhances the capillary action and / or thus improves the start-up of the two-phase cooling system. The tapering of the cooling channel loop in particular means a reduction in the cross section in a subsection of the cooling channel loop.

[0046] The fifth variant form proposes that the two-phase cooling system has an auxiliary heat source directly coupled to the cooling channel loop as an auxiliary element. The auxiliary heat source is usually an electrical component such as a heating resistor, and / or an inductive component. In particular, the auxiliary heat source is activatable before the heat source is operated and / or before the X-ray is generated. After the two-phase cooling system is started, the auxiliary heat source is usually deactivated. The auxiliary heat source is activated, for example, in the following manner: the auxiliary heat source is turned on, that is, put into operation. The auxiliary heat source and the heat source can be operated alternately, for example. The auxiliary heat source can be operated in particular in the time period between providing high voltage and / or X-ray generation. The auxiliary heat source can be operated in principle, during which the heat source is operated. The auxiliary heat source usually generates a loss power introduction of one tenth, especially one thousandth of the heat source. The auxiliary heat source usually only generates loss power. In particular, the auxiliary heat source is set up to assist the start-up of the two-phase cooling system, especially the start-up of the oscillating heat pipe, by the loss power introduced. In particular, the auxiliary heat source realizes: when at least one power electronic circuit component is not running, the oscillating heat pipe is started or started. The auxiliary heat source is usually arranged adjacent to the heat source and / or heat sink. In principle, it is conceivable to arrange the auxiliary heat source on a subsection of the cooling channel circuit at which the working medium is displaced by gravity and / or centrifugal force, in order to preferably counteract the displacement.

[0047] One embodiment proposes that the cooling channel loop is twisted so that at least two sub-planes of the cooling channel loop are at an angle greater than 0° to each other. The angle is usually greater than 0° and less than 360°. According to this embodiment, the cooling channel loop is not completely flat, that is, it is not designed in a single plane, but has an angle, such as a bend or a rounded portion. In a side view or in a cross section running through the cooling channel loop, the cooling channel loop can form an L-shape, a U-shape or an O-shape, for example. In the latter case, the cooling channel loop is twisted so that the cooling channel loop can form a circle. The sub-planes of the cooling channel loop particularly include the following channel sections of the cooling channel loop, which are at least approximately located in a geometric plane. For example, if the cooling channel loop forms an L-shape, one of the two sub-planes is located on the first side of the L-shape and the other of the two sub-planes is located on the second side of the L-shape. In principle, as an improved form of this embodiment, it is conceivable that a separate cooling channel loop is provided in each sub-plane, and the cooling channel loop is directly thermally coupled in pairs, for example, by means of an insert. This embodiment is particularly advantageous since it allows the two-phase cooling system to be designed more flexibly in terms of space.

[0048] In the present application, introduction into the cooling block means in particular that the envelope of the cooling block completely surrounds the introduced unit. The envelope can consist completely of the material of the cooling block and thus of the surface of the cooling block, or alternatively at least partially surround the surface of the introduced unit together. In other words, the introduced unit can be completely surrounded by the cooling block, or the introduced unit, in particular arranged on the cooling block, forms at least a part of one side of this arrangement consisting of the cooling block and the introduced unit.

[0049] One embodiment proposes that a heat source, in particular at least one power electronic circuit component, is introduced into the cooling block as part of a channel wall of the cooling block surrounding a working medium in a cooling channel loop, and the working medium is electrically insulated. The advantage of this embodiment is, in particular, that the working medium is in direct contact with the heat source, thereby typically increasing direct thermal coupling. Therefore, the heat dissipation of the heat source is usually carried out directly on the surface of at least one power electronic circuit component. In this case, the working medium is electrically insulated in order to ensure the safe operation of the X-ray high-voltage generator. The heat source can be oriented toward the cooling circuit with the surface to be most strongly dissipated. The heat source can be at least one power electronic circuit component of a circuit device. The circuit device can be set up to provide high voltage.

[0050] One embodiment proposes that the cooling block is coated at least partially with a fluid-tight layer. The cooling block is then advantageously protected from intrusion of liquids and / or gases. The fluid-tight layer can, for example, comprise SiO2 and / or ceramic and / or metal. The fluid-tight layer is generally a layer in contact with the cooling block, in particular a coating of the cooling block. The surface of the cooling block coated with the fluid-tight layer is in particular a fluid-tight surface. Surfaces without a fluid-tight layer or surfaces that are not adjacent to any other fluid-tight surface are generally permeable.

[0051] One embodiment provides that a holding device and / or a fixing element for mechanically stabilizing the cooling block is introduced into the cooling block. This embodiment is particularly advantageous because the holding device and / or the fixing element can be integrated into the cooling block with a polymer by means of an additive manufacturing method. In particular, the fixing element can be a plug for connecting a flat module and / or a spring element.

[0052] One embodiment proposes to introduce a printed circuit board into a cooling block, wherein the printed circuit board is set up for the electrical supply of a heat source. The printed circuit board can be equipped with at least one power electronic circuit component, in particular a circuit device of an X-ray high voltage generator. Alternatively or additionally, other resistive components and / or capacitive components and / or inductive components can be provided on the printed circuit board. The fixing of at least one power electronic circuit component and / or component is carried out in particular according to SMD installation and / or THT installation. SMD installation is advantageous because it is usually not necessary to penetrate the usually fluid-tight printed conductor plane and therefore does not require sealing perforations. The printed circuit board is in particular a board. The printed circuit board can be oriented toward the cooling block with the device side. Alternatively, the device side of the printed circuit board can be facing away from the cooling block. For example, the printed circuit board can have a plurality of printed conductor planes, in particular composed of copper and / or plastic and / or paper and / or ceramic. One of the printed conductor planes, for example, the layer facing away from the cooling block, can be continuously formed to perform electromagnetic shielding and / or electrical insulation and / or preferably for sealing. In particular, such a conductor track plane forms a fluid-tight layer and / or is a metallic element.

[0053] One embodiment proposes that the printed circuit board is multilayer, wherein at least two of the printed conductor planes of the printed circuit board are electrically conductive, and between the two electrically conductive printed circuit board planes, a diffusion channel is formed in a permeable printed conductor plane arranged between the two electrically conductive printed conductor planes, wherein the opposite permeable ends of the diffusion channel are spaced apart from each other, so that the diffusion channel is fluid-tight due to its length. Diffusion channel is defined as a section in the medium where fluid, such as gas molecules, are most likely to pass due to the properties, especially porosity, of the medium. For example, the fluid in the diffusion channel can propagate along the permeable printed conductor plane, rather than passing through the adjacent electrically conductive printed conductor plane. The electrically conductive printed conductor plane usually has metal, especially copper. The permeable printed conductor plane usually has plastic and / or paper. The printed circuit board does not usually have a continuous through hole, but has a blind hole and / or a buried hole. The disadvantage of a continuous through hole is especially that the printed circuit board needs to be sealed at such a through hole. Discontinuous through holes do not require continuous drilling and therefore do not have this disadvantage. In this embodiment, the conductive conductor plane does not usually cover the entire surface of the cooling block. Insulating sections are usually provided at the ends of the diffusion channel. The insulating sections are provided to electrically insulate at least two sections of the conductive conductor plane. The conductive conductor plane with the insulating sections is interrupted. In particular, the insulating sections realize a connection perpendicular to the conductor plane so that the conductor plane can act fluid-tightly due to the interruption. That is to say, it is advantageous that the printed circuit board is fluid-tight because the spacing between the insulating sections is selected to be large enough. Preferably, the opposite ends of the diffusion channel are far away from each other and have a permeable conductor plane along the diffusion channel so that the fluid cannot propagate through the diffusion channel due to the length of the diffusion channel.

[0054] One embodiment provides that the cooling block is dimensioned in such a way that the shortest diffusion path between the cooling channel loop and the permeable surface of the cooling block is fluid-tight due to its length. In other words, the fluid-tightness is advantageously achieved in that the diffusion path is sufficiently long. Therefore, if the shortest diffusion path is fluid-tight, then the entire cooling block is fluid-tight.

[0055] One embodiment provides that the cooling block is at least partially enclosed by a metal element, in particular by a printed circuit board and / or a film and / or a metal plate. The metal element is in particular fluid-tight, shielding and / or electrically conductive and can be provided for electromagnetic shielding and / or electrical insulation and / or as a fluid-tight layer for sealing the cooling block against the escape of the working medium. The metal element can in particular be designed as a sealing cover for sealing. The metal element can in particular be a printed circuit board. The metal element can be multilayered.

[0056] One embodiment proposes that the two-phase cooling system has an intermediate heat reservoir, in particular made of copper and / or aluminum, wherein the intermediate heat reservoir is directly thermally coupled to at least one power electronic circuit component by means of a heat distribution element, and wherein the heat distribution element is planarly adjacent to the cooling channel loop. The intermediate heat reservoir is, for example, a metal block, in particular composed of copper and / or aluminum. The intermediate heat reservoir preferably implements a buffer for the introduction of the maximum power loss caused by the heat source. The heat distribution element is in particular composed of diamond and / or graphite material. The heat distribution element usually increases the heat transfer surface between the working medium and at least one power electronic circuit component by planar adjacency, and thus improves direct thermal coupling. The heat distribution element can form a channel wall in a subsection of the cooling channel loop in particular. The heat distribution element can have a length associated with the distance between the intermediate heat reservoir and the heat source.

[0057] The X-ray high voltage generator for providing high voltage according to the present invention has a two-phase cooling system and a circuit arrangement, wherein the circuit arrangement has at least one power electronic circuit component, wherein the at least one power electronic circuit component forms a heat source during operation, wherein the at least one power electronic circuit component is directly thermally coupled to the two-phase cooling system to dissipate heat from the heat source at a heat sink. The circuit arrangement can be at least partially arranged on a printed circuit board or integrated into the printed circuit board.

[0058] Since the X-ray high voltage generator has a two-phase cooling system, the X-ray high voltage generator shares the advantages and implementations thereof previously discussed in connection with the two-phase cooling system.

[0059] The X-ray high voltage generator is configured to provide high voltage, especially at the output of the X-ray high voltage generator. Providing high voltage especially includes generating high voltage. When providing, the X-ray high voltage generator especially converts the commonly used grid voltage (usually not in the kV range, but lower than the kV range) or the intermediate circuit voltage of the input side into high voltage. High voltage is usually applied at the output of the X-ray high voltage generator. High voltage is usually greater than 10kV and / or less than 200kV, for example, between 20kV and 150kV, especially between 70kV and 120kV. The X-ray high voltage generator, such as the output end, can be connected to the input end of the X-ray tube, especially the X-ray tube, by means of a high voltage cable, and is usually used to transmit high voltage. In particular, the X-ray tube can generate X-rays according to the high voltage provided by the X-ray high voltage generator. The generated X-rays usually have an energy spectrum that reaches the value of the high voltage multiplied by the basic charge e. X-rays are usually not generated in the X-ray high voltage generator but in the X-ray tube.

[0060] The high voltage is provided in particular by means of a circuit arrangement. The circuit arrangement comprises at least one power electronic circuit component for providing, in particular generating, the high voltage. Typically, the circuit arrangement additionally comprises other electronic components and / or power electronic circuit components. For example, the at least one power electronic circuit component can be a power transistor, a power electronic device, an inductive device, a resistive device and / or a capacitive device. The at least one power electronic circuit component can be mounted in particular in a TO-247 housing, an SMD housing, a THT housing or a power module.

[0061] When the X-ray high voltage generator is in operation, high voltage is usually provided. During this period, at least one power electronic circuit component of the circuit device is usually in operation, especially under load. The operation of at least one power electronic circuit component requires the use of electrical power, of which usually only a part of the electrical power is provided in the form of high voltage and the other part is reduced as loss power. At least one power electronic circuit component is a heat source at least in operation. The loss power introduction is usually so high that the heat source is cooled by the two-phase cooling system in operation. During operation, the loss power introduction may vary. In particular, after the high voltage is provided, at least one power electronic circuit component can continue to exist as a heat source to be cooled for a certain period of time.

[0062] The X-ray radiator according to the invention has:

[0063] - an X-ray high voltage generator for providing high voltage, and

[0064] - An X-ray tube for generating X-rays using the supplied high voltage.

[0065] Since the X-ray radiator has a two-phase cooling system, the X-ray radiator shares the advantages discussed previously in connection with the two-phase cooling system and its embodiments. In particular, the X-ray radiator forms an X-ray generating device.

[0066] X-ray tubes usually have an evacuated X-ray tube housing which encloses a high vacuum, an electron emitter and an anode. The anode can be a rotating anode or a vertical anode. In the case of a rotating anode, a distinction is usually made between rotating anode X-ray tubes, in which the anode rotates in the X-ray tube housing, and rotary piston X-ray tubes, in which the anode rotates together with the X-ray tube housing.

[0067] Electron emitters are in particular field effect emitters or thermionic emitters. Field effect emitters usually have carbon nanotubes or silicon nanotubes or molybdenum nanotubes. In field effect emitters, electron emission is usually caused by applying a gate voltage, which extracts electrons from the nanotubes due to the electric field occurring at the tips of the nanotubes, thereby forming an electron current. In addition to or as an alternative to switching by means of a gate voltage, the generated electron flow can be blocked by means of a blocking gate. A limited current unit can be connected upstream of the nanotubes. Thermionic emitters are, for example, spiral emitters or planar emitters, which can be heated directly or indirectly.

[0068] The electron emitter is designed as a cathode or is arranged together with a cathode opposite to the anode. The provided high voltage is applied between the cathode and the anode. The X-ray high voltage generator is connected to the X-ray tube to transmit the provided high voltage. The electrons emitted by the electron emitter are accelerated toward the anode by means of the high voltage and generate X-ray radiation in the focus on the anode during the interaction.

[0069] The generated X-rays can be used in particular for medical imaging and / or material testing. Typical applications in medical imaging are angiography, computed tomography, fluoroscopy, imaging for radiation therapy, mammography and / or radiography. X-ray emitters are usually used in combination with X-ray detectors. In addition, depending on the type of application, they can be integrated into imaging facilities such as C-arms, computed tomography scanners, etc.

[0070] The computer tomography apparatus according to the present invention comprises:

[0071] - a circular frame having a rotating part and a fixed part, and

[0072] - X-ray high voltage generator, or

[0073] - an X-ray radiator having an X-ray high voltage generator,

[0074] The two-phase cooling system is arranged on the rack.

[0075] Since the computed tomography apparatus has a two-phase cooling system, the computed tomography apparatus shares the advantages and embodiments thereof previously discussed in connection with the two-phase cooling system.

[0076] The rotating part of the gantry is usually separated from the fixed part by an air gap. For example, the power for operating the high-voltage generator and thus the X-ray emitter is transmitted from the fixed part to the rotating part via the air gap in a contact- or contactless manner. In the opposite direction, the data of the X-ray detector are preferably transmitted contactlessly, for example electrostatically, capacitively or optically. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] The accompanying drawings show:

[0078] Figure 1 A conventional X-ray high voltage generator according to the prior art is shown.

[0079] Figure 2 A two-phase cooling system according to the invention is shown,

[0080] Figure 3 A first embodiment of a two-phase cooling system is shown,

[0081] Figure 4 A second embodiment of a two-phase cooling system is shown,

[0082] Figure 5 A third embodiment of a two-phase cooling system is shown,

[0083] Figure 6 A fourth embodiment of a two-phase cooling system is shown,

[0084] Figure 7 A fifth embodiment of a two-phase cooling system is shown,

[0085] Figure 8 A sixth embodiment of a two-phase cooling system is shown,

[0086] Fig. 9 The X-ray high voltage generator according to the present invention is shown,

[0087] Fig.10 A first embodiment of an X-ray high voltage generator is shown.

[0088] Fig.11 A second embodiment of the X-ray high voltage generator is shown.

[0089] Fig.12 shows an X-ray radiator according to the invention, and

[0090] Fig.13 A computer tomography device according to the invention is shown. DETAILED DESCRIPTION

[0091] Figure 1 A conventional X-ray high voltage generator 10 according to the prior art is shown.

[0092] As part of a circuit arrangement for providing high voltage, the X-ray high voltage generator 10 has two power electronic circuit components 11 as heat sources. The two power electronic circuit components 11 are respectively arranged on a cooling block 12, which is composed of copper, for example. The carrier plate 13 carries the two cooling blocks 12 and connects the cooling blocks to the heat sink 14. The carrier plate 13 can be electrically insulated. Alternatively or additionally, as part of a conventional X-ray high voltage generator 10, an insulating layer can be provided to electrically insulate the power electronic circuit components 11. The arrows represent the heat flow from the heat source to the heat sink 14.

[0093] Figure 2 A portion of a two-phase cooling system 22 for an X-ray high voltage generator according to the invention is shown.

[0094] The two-phase cooling system 22 has a radiator 23 or acts as a radiator 23 on the side facing away from the heat source. In order to dissipate heat to the heat source, the two-phase cooling system 22 has a cooling block 24. The cooling block 24 surrounds the cooling channel loop 25 in space. The cooling channel loop 25 is a part of the two-phase cooling system 22. The cooling channel loop 25 is at least partially filled with a working medium 26 and acts as an oscillating heat pipe. The cooling block 24 is made of a material having a polymer. The polymer can be polypropylene, polycarbonate, polyetheretherketone, polyamide or acrylonitrile-butadiene-styrene copolymer.

[0095] Purely for illustration purposes, the cooling channel loop 25 has channel segments arranged in a meandering manner. 10 parallel channel segments are shown by way of example. The number of parallel channel segments can be more than 50, in particular more than 500, for example between 2 and 1000. The spacing between the channel segments, i.e. the ridge width, is typically between 0.01 mm and 5 mm, for example between 0.1 mm and 1 mm. When the cooling block 24 is made of a polymer, the ridge width is, for example, at least 0.3 mm, preferably 0.5 mm.

[0096] In this exemplary embodiment, the material contains only polymers. Alternatively, the material can also contain metals and / or ceramics, wherein the material is homogenized by mixing.

[0097] exist Figure 2 In FIG. 2 , a cross section along the plane of the cooling channel circuit 25 is shown. The section plane AA is at Figure 4 Indicated in the following Figures 3 to 11 In, with Figure 2 In contrast, the plane of the cooling channel loop 25 is substantially perpendicular to the plane of the drawing.

[0098] Figure 3 A first embodiment of a two-phase cooling system 22 is shown.

[0099] The two-phase cooling system 22 has an intermediate heat reservoir 29, in particular made of copper and / or aluminum. The intermediate heat reservoir 29 can be directly thermally coupled to at least one power electronic circuit component 21 (e.g., an X-ray high-voltage generator) by means of a heat distribution element 30, in particular made of diamond and / or graphite material, and in this embodiment directly thermally coupled as a heat source. The heat distribution element 30 is planarly adjacent to the cooling channel circuit 25.

[0100] In this exemplary embodiment, the cooling block 24 has an insert 27, in particular made of copper and / or aluminum, wherein the material of the insert 27 has a higher thermal conductivity than the material of the cooling block 24. In principle, an insert element can be provided between the heat distribution element 30 and the intermediate heat storage 29 and / or the at least one power electronic circuit component 21 and / or the heat sink 23. Figure 3 The three insert elements of the central insert 27 respectively thermally couple the intermediate heat storage 29, at least one power electronics component 21 as heat source and the heat sink 23 directly to the cooling channel circuit 25. In this embodiment, the heat sink 23 is provided with a surface-enhancing shape, in particular cooling fins.

[0101] In this figure, the intermediate heat reservoir 29 is arranged such that at least one power electronic circuit component 21 is arranged between the intermediate heat reservoir 29 and the heat sink 23. Alternatively, it is conceivable that the intermediate heat reservoir 29 is arranged between at least one power electronic circuit component 21 and the heat sink 23. In this case, the intermediate refers to the shortest section along the cooling channel loop 25.

[0102] Figure 4 A second embodiment of a two-phase cooling system 22 is shown.

[0103] The heat source, here at least one power electronic circuit component 21, is introduced into the cooling block 24 as part of a channel wall of the cooling block 24 surrounding a working medium 26 in a cooling channel circuit 25. The working medium 26 is a dielectric or electrically insulating medium.

[0104] Figure 5 A third embodiment of a two-phase cooling system 22 is shown.

[0105] The cooling block 24 is at least partially coated as a fluid-tight layer with a metal element 34. In this exemplary embodiment, the cooling block 24 is thus completely encased.

[0106] A heat source, for example at least one power electronic circuit component 21, is introduced into the cooling block 24 as part of its channel wall surrounding a working medium 26 in a cooling channel circuit 25. In this case, the working medium 26 is a dielectric or electrically insulating.

[0107] A printed circuit board including a current supply 35 is introduced into the cooling block 24, which is designed to supply power to the X-ray high voltage generator 20, for example at least one power electronics component 21. In principle, it is conceivable that the current supply 35 is designed as a busbar. The printed circuit board forms the metal element 34.

[0108] Figure 6 A fourth embodiment of a two-phase cooling system 22 is shown.

[0109] In this exemplary embodiment, the cooling block 24 has an insert 27. The material of the insert 27 has a higher thermal conductivity than the material of the cooling block 24. The cooling channel loop 25 is twisted so that at least two (in this exemplary embodiment, four) subplanes 25.T of the cooling channel loop 25 are at an angle greater than 0° to one another.

[0110] Additionally, in Fig.10 , a fixing element 37, for example a spring element, for fixing at least one power electronic circuit component 21 is introduced into the cooling block 24 to mechanically stabilize the cooling block 24 on the high-voltage generator 20. The metal element 34, in this case the printed circuit board, is fixed to the cooling block 24 using a holding device 36. The holding device 36 is, for example, a screw and / or a clip.

[0111] The heat sink block 24 offers the advantage that, due to the twisted orientation, geometrically complex structures of the two-phase cooling system 22 can be realized, for example recesses through the metal element 34 .

[0112] Figure 7 A fifth embodiment of a two-phase cooling system 22 is shown.

[0113] A printed circuit board is introduced into the cooling block 24, which is designed to supply power to the heat source. In this embodiment, the heat source forms a power electronics component 21. The heat source is supplied with power by means of discontinuous through-holes 35 as current conveyors in the printed circuit board.

[0114] The printed circuit board is multi-layered and therefore has a plurality of (in the exemplary embodiment, five) conductor track planes 46. The printed circuit board, in particular the plurality of conductor track planes 46, are sealed laterally with a fluid-tight sealing layer 48.

[0115] At least two 46.L of the printed circuit board's conductor track planes 46 are electrically conductive. Between the two electrically conductive conductor track planes 46.L, a diffusion channel 47 is formed in a permeable conductor track plane arranged between the two electrically conductive conductor track planes 46.L. The diffusion channel 47 is indicated by a dotted double arrow. The opposite permeable ends of the diffusion channel 47 are spaced apart from one another, so that the diffusion channel 47 is fluid-tight due to its length.

[0116] The heat source is introduced into the cooling block 24 as part of the channel wall of the cooling block 24 surrounding the working medium 26 in the cooling channel loop 25. The working medium 26 is electrically insulating. The two-phase cooling system 22 is fixed on a carrier plate 39. The latter couples the two-phase cooling system 22 and the radiator 23. At least one insert 27 improves the heat transfer from the cooling channel loop 25 to the radiator 23.

[0117] Figure 8 A sixth embodiment of a two-phase cooling system 22 is shown.

[0118] The two-phase cooling system 22 is designed to dissipate heat from two heat sources. Two power electronic components 21 form the heat sources, one of which is connected to the current supply 35 according to SMD mounting and the other is connected to the current supply 35 according to THT mounting.

[0119] In this exemplary embodiment, the power supply 35 is a busbar. Alternatively, it is conceivable to use an electrically conductive conductor track plane of a printed circuit board as the power supply.

[0120] The cooling block 24 is dimensioned in such a way that the shortest diffusion path between the cooling channel loop 25 and the permeable surface of the cooling block 24 is fluid-tight due to its length. The permeable surface of the cooling block 24 is indicated by dashed lines.

[0121] In this exemplary embodiment, the cooling block 24 is constructed in multiple parts. The upper part is arranged as a kind of cover above the heat source and the lower part is arranged below the heat source.

[0122] Fig. 9 An X-ray high voltage generator 20 is shown.

[0123] The X-ray high voltage generator 20 is configured to provide a high voltage and has a two-phase cooling system 22 and a circuit arrangement having at least one power electronic circuit component 21. The at least one power electronic circuit component 21 forms a heat source during operation. The at least one power electronic circuit component 21 is directly thermally coupled to the two-phase cooling system 22 to dissipate heat from the heat source at a heat sink 23.

[0124] The carrier plate 39 is connected to the cooling block 24 and is directly thermally coupled in order to further improve the cooling performance. In particular, the carrier plate 39 thus forms the heat sink 23 of the two-phase cooling system 22. The carrier plate 39 can be, for example, a housing of the X-ray high voltage generator 20 or a frame of a not shown computed tomography device 50 or a support of a not shown X-ray radiator 40.

[0125] Fig.10 A first embodiment of an X-ray high voltage generator 20 is shown.

[0126] For better heat dissipation, the insert elements of the insert 27 are flatly adjacent to the carrier plate 39 in order to improve the heat introduction into the carrier plate 39. The heat sink 23 is directly thermally coupled to the carrier plate 39. The latter can be, for example, a frame of the not shown computed tomography device 40, in particular the rotating part 52.

[0127] and Fig. 9 compared to, Fig.10 The carrier plate 39 in the embodiment is not arranged on the side of the heat sink block 24 but on the bottom side.

[0128] Fig.11 A second embodiment of the X-ray high voltage generator 20 is shown.

[0129] The heat source, i.e. at least one power electronic circuit component 21, is introduced into the cooling block 24 as part of a channel wall of the cooling block 24 surrounding a working medium 26 in a cooling channel loop 25. As a result, the at least one power electronic circuit component 21 is directly cooled by the working medium 26. In this case, the working medium 26 is a dielectric or electrically insulating.

[0130] The cooling block 24 is sealed on the side with at least one power electronic circuit component 21 by means of a metal element 34 as a fluid-tight layer. The metal element 34 is a printed circuit board with a plurality of conductor track planes. The printed circuit board is a multilayer board, wherein its conductor track planes are provided with so-called "buried vias" as current conveying sections 35.

[0131] Fig.12 An X-ray radiator 40 according to the invention is shown.

[0132] The X-ray radiator 40 has an X-ray high voltage generator 20 for providing high voltage and an X-ray tube 41. The X-ray high voltage generator 20 and the X-ray tube 41 are connected to a high voltage cable 42 to transmit the high voltage.

[0133] The X-ray tube 42 has an X-ray tube housing 43, an electron emitter 44 as a cathode provided therein, and an anode 45. A high voltage is applied between the electron emitter 44 and the anode 45.

[0134] Fig.13 A computed tomography device 50 is shown.

[0135] The computer tomography device 50 has a circular gantry having a rotating part 52 and a fixed part 51 and an X-ray high voltage generator 20 as a part of the X-ray emitter 40. The two-phase cooling system 22 is arranged on the gantry. In this embodiment, the rotating part 52 and the fixed part 51 are arranged in a disc shape. Alternatively, a drum-shaped embodiment is also considered.

[0136] The X-ray radiator 40 is disposed on the rotating part 52 . A patient 53 is supported on an examination bed 54 .

[0137] Although the present invention has been illustrated and described in detail through the preferred embodiments, the present invention is not limited to the disclosed embodiments and those skilled in the art can derive other variations therefrom without departing from the protection scope of the present invention.

Claims

1. A two-phase cooling system (22) for an X-ray high voltage generator (20), comprising: - a cooling block (24), wherein the cooling block (24) spatially surrounds a cooling channel circuit (25), wherein the cooling channel circuit (25) is at least partially filled with a working medium (26) and acts as an oscillating heat pipe, and - a heat sink (23) for dissipating heat from a heat source, It is characterized in that The cooling block (24) is made of a material having a polymer. A printed circuit board is introduced into the cooling block (24), the printed circuit board being designed to supply power to the heat source. The printed circuit board is multilayered, at least two of the conductor track planes (46) of the printed circuit board are electrically conductive, and a diffusion channel (47) is formed between the two electrically conductive conductor track planes (46) in a permeable conductor track plane arranged between the two electrically conductive conductor track planes (46). The opposite permeable ends of the diffusion channel (47) are spaced apart from one another so that the diffusion channel is fluid-tight due to its length.

2. The two-phase cooling system (22) according to claim 1, wherein the material comprises only the polymer.

3. The two-phase cooling system (22) according to claim 1, The material further comprises metal and / or ceramic, and the material is homogenized by mixing.

4. A two-phase cooling system (22) according to any one of claims 1 to 3, in, A holding device (36) and / or a fixing element (37) is introduced into the cooling block (24) in order to mechanically stabilize the cooling block (24) on the X-ray high-voltage generator (20).

5. A two-phase cooling system (22) according to any one of claims 1 to 3, The cooling block (24) is dimensioned in such a way that the shortest diffusion path between the cooling channel circuit (25) and the permeable surface of the cooling block (24) is fluid-tight due to its length.

6. A two-phase cooling system (22) according to any one of claims 1 to 3, The heat source is introduced into the cooling block (24) as part of a channel wall of the cooling block (24) surrounding a working medium (26) in the cooling channel circuit (25), and the working medium (26) is electrically insulated.

7. A two-phase cooling system (22) according to any one of claims 1 to 3, The cooling block (24) is at least partially coated with a fluid-tight layer.

8. A two-phase cooling system (22) according to any one of claims 1 to 3, The two-phase cooling system (22) has an intermediate heat reservoir (29), wherein the intermediate heat reservoir (29) can be directly thermally coupled to the heat source by means of a heat distribution element (30), and wherein the heat distribution element (30) adjoins the cooling channel circuit (25) in a planar manner.

9. A two-phase cooling system (22) according to any one of claims 1 to 3, The heat sink block (24) has an insert (27), wherein the material of the insert (27) has a higher thermal conductivity than the material of the heat sink block (24).

10. The two-phase cooling system (22) according to any one of claims 1 to 3, The cooling channel loop (25) is designed to be twisted such that at least two subplanes (25.T) of the cooling channel loop (25) form an angle greater than 0° with respect to one another.

11. The two-phase cooling system (22) according to claim 8, The intermediate heat storage (29) is made of copper and / or aluminum.

12. The two-phase cooling system (22) according to claim 8, The heat distribution element (30) is made of diamond and / or graphite material.

13. The two-phase cooling system (22) according to claim 9, The insert (27) consists of copper and / or aluminum.

14. An X-ray high voltage generator (20) for providing high voltage, comprising: - a two-phase cooling system (22) according to any one of claims 1 to 13, and - A circuit arrangement having at least one power electronic circuit component (21), wherein the at least one power electronic circuit component (21) forms a heat source during operation, wherein the at least one power electronic circuit component (21) is directly thermally coupled to the two-phase cooling system (22) for dissipating heat from the heat source at the heat sink (23).

15. An X-ray radiator (40), comprising: - an X-ray high voltage generator (20) for providing high voltage according to claim 14, and - an X-ray tube (41) for generating X-rays using the provided high voltage.

16. A computer tomography device (50), comprising: - an X-ray high voltage generator (20) according to claim 14, or - an X-ray radiator (40) according to claim 15, and - a frame having a rotating part (52) and a fixed part (51), The two-phase cooling system (22) is arranged on the frame.

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