CN220675986U

CN220675986U - Magnetic resonance system with cryocooler and thermal coupling to heating application

Info

Publication number: CN220675986U
Application number: CN202320204259.2U
Authority: CN
Inventors: 尼古拉斯·阿利
Original assignee: Siemens Healthineers AG
Current assignee: Siemens Healthineers AG
Priority date: 2022-02-15
Filing date: 2023-02-14
Publication date: 2024-03-29
Anticipated expiration: 2033-02-14
Also published as: DE202022100849U1

Abstract

The utility model relates to a magnetic resonance apparatus (10), the magnetic resonance apparatus (10) comprising a cryocooler (13) having a compressor, wherein the compressor is thermally coupled to at least one fluid flow, and wherein at least one fluid flow is configured for absorbing thermal energy from the compressor and delivering the thermal energy to a heating application (18).

Description

Magnetic resonance system with cryocooler and thermal coupling to heating application

Technical Field

Magnetic resonance tomography is a known imaging method by means of which magnetic resonance images of the interior of an examination object can be generated. In performing magnetic resonance imaging, the examination subject is usually positioned in a strong, static and homogeneous basic magnetic field (B0 magnetic field) of the magnetic resonance apparatus. The basic magnetic field can have a magnetic field strength of 0.2 tesla to 7 tesla, so that the nuclear spins of the examination subject are oriented along the basic magnetic field. In order to trigger the so-called nuclear spin resonance, a high-frequency signal, a so-called excitation pulse (B1 magnetic field), is introduced into the examination object. Each excitation pulse causes the magnetization of a particular nuclear spin of the examination object to deviate from the basic magnetic field by an amount which is also known as the flip angle. The excitation pulse can have an alternating magnetic field whose frequency corresponds to the larmor frequency at the corresponding static magnetic field strength. The excited nuclear spins can have a rotating and decaying magnetization (nuclear spin resonance), which can be detected as magnetic resonance signals by means of a special antenna. The magnetic gradient field can be superimposed with the basic magnetic field to spatially encode the nuclear spin resonance of the examination object.

Background

The received magnetic resonance signals are typically digitized and stored as complex values in a K-space matrix. The K-space matrix can be used as a basis for reconstructing magnetic resonance images and determining spectroscopic data. Reconstruction of magnetic resonance images is usually performed by means of a multidimensional fourier transformation of a K-space matrix.

Cryocoolers are commonly used in magnetic resonance apparatus with superconducting magnets that cool the superconducting magnets to a desired temperature level. Such a temperature level can lie, for example, between 3K and 80K. Cryocoolers are based on thermodynamic processes in which compressed working fluid is expanded to provide a cooling effect. In contrast, thermal energy is generated when the working fluid is compressed by means of a compressor, which can be conducted away by means of external cooling. The thermal energy drawn off by the compressor is in this case several times the cooling power of the cryocooler.

To remove heat energy from the compressor, the compressor can be connected to an external cooling circuit, such as a cold water kit or a refrigerator with a separate sub-cooling device. The external cooling circuit can be designed to remove the thermal energy of the compressor, but also of other components of the magnetic resonance system.

The operation of the external cooling circuit is combined with an additional energy expenditure, which may represent a considerable fraction of the costs associated with the operation of the magnetic resonance system.

Disclosure of Invention

The object of the utility model is to reduce or minimize the additional energy consumption for an external cooling circuit.

This object is achieved by a magnetic resonance apparatus according to the utility model. Advantageous embodiments and advantageous modifications are described below.

The magnetic resonance system according to the utility model comprises a cryocooler having a compressor, wherein the compressor is thermally coupled to at least one fluid flow, and wherein the at least one fluid flow is configured for absorbing thermal energy from the compressor and for feeding the heating application.

The cryocooler can be designed in particular as a pulse tube cooler, a Gifford-McMahon cooler, a stirling (Sterling) cryocooler, a Joule-Thomson (Joule-Thomson) cooler, etc. The cryostat can be designed to cool down to a predetermined temperature, the cryostat surrounding the superconducting magnet of the magnetic resonance system on the outer circumference. The predetermined temperature can be characterized in particular by a temperature level at which the superconducting material of the superconducting magnet has superconducting properties. Alternatively, the cryocooler can be designed to cool the superconducting magnet directly, for example by means of a thermally conductive mechanical connection (thermal bus) and/or a heat pipe (heat pipe).

The compressor can be configured, for example, as a helium compressor. Helium compressors are particularly configured for compressing gaseous helium. However, the compressor can also be configured to compress any other working fluid. Such a working fluid can be, inter alia, a cryogenic substance, such as helium, nitrogen, hydrogen, argon, oxygen, etc.

The compressor preferably has a heat exchanger, which is designed to thermally couple the compressor to the at least one fluid flow. For example, the compressor can have an internal cooling circuit, in particular an oil circuit. The oil circuit can be configured to absorb thermal energy released by compressing the working fluid. Furthermore, the internal cooling circuit can be coupled with at least one fluid flow by means of a heat exchanger (e.g. a liquid-liquid heat exchanger) in order to transfer the thermal energy released when compressing the working fluid onto the at least one fluid flow. In addition to the oil circuit, internal cooling circuits based on water or other media are of course also conceivable.

It is also conceivable that at least one fluid flow is thermally coupled to the working fluid by means of a gas-liquid heat exchanger. In this case the internal cooling circuit can be omitted.

Suitable heat exchanger types are, for example, plate heat exchangers, tube bundle heat exchangers, sleeve heat exchangers, laminated heat exchangers, etc. The heat transfer principle of the heat exchanger can be based here on direct, indirect or semi-indirect heat transfer.

Preferably, the at least one fluid flow is thermally coupled to the working fluid of the compressor by means of a heat exchanger such that thermal energy of the working fluid is transferred to the at least one fluid flow when the working fluid is compressed. This can mean that the temperature of the working fluid of the compressor and/or the cooling medium of the internal cooling circuit is reduced while the temperature of at least one fluid flow is increased while passing through the heat exchanger.

The heat energy absorbed by the at least one fluid stream is transferred to a heating application. The heating application can be any application in which thermal energy of at least one fluid flow is delivered as effective heat to a subject. Examples of heating applications include space and/or building heating, heating of fresh air streams, hot water treatment, and the like. In general, the implementation of heating applications is carried out by means of a suitable heating system, in particular a building heating system, to which additional examples are listed below.

By means of the magnetic resonance apparatus according to the utility model, the energy efficiency of the cooling of the magnetic resonance apparatus can be increased in an advantageous manner. In particular, by using the thermal energy of the compressor, the energy requirement of the heating application at the location of the magnetic resonance apparatus can be reduced in an advantageous manner, whereby the costs associated with the operation of the heating application can be reduced. Furthermore, by using the thermal energy of the compressor in the heating application, the cooling requirement of the magnetic resonance apparatus can be reduced, whereby the energy requirement of the external cooling circuit and/or the costs associated with operation can advantageously be reduced.

In one embodiment of the magnetic resonance apparatus according to the utility model, the at least one fluid flow is thermally coupled to the second fluid flow. The second fluid flow is configured to absorb thermal energy of at least one fluid flow and deliver it to the heating application.

The material composition of the second fluid stream can be consistent with, or different from, the material composition of at least one of the fluid streams. It is also conceivable that the aggregation state of the second fluid flow corresponds to or differs from the aggregation state of the at least one fluid flow. For example, at least one fluid stream can have a water-based heat transfer medium, while a second fluid stream includes a heat transfer medium based on ethylene glycol, a water-ethylene glycol mixture, air, a phase change slurry, or the like. Of course, combinations of additional or alternative heat transfer mediums are contemplated. For example, the at least one fluid stream can comprise a heat transfer medium based on oil, glycol, a water-glycol mixture, or a phase change slurry, while the second fluid stream comprises the same or a different heat transfer medium. The phase-change slurry can be a medium that can be delivered by means of a pump, with PCM (phase change material, phase-change material) in encapsulated, dispersed, suspended or emulsified form. By using a phase-change slurry, the heat capacity of at least one fluid stream and/or the second fluid stream can be increased in an advantageous manner. Further, the temperature constancy of at least one fluid stream as well as the second fluid stream can be improved by using a phase-change slurry. The temperature fluctuations at the compressor can thus be avoided in an advantageous manner.

In a preferred embodiment, the at least one fluid flow and the second fluid flow are thermally coupled to each other by means of a plate heat exchanger or a tube bundle heat exchanger.

By thermally coupling the at least one fluid stream with the second fluid stream, the thermal energy of the compressor can also be advantageously used in heating applications that use a different heat transfer medium than the at least one fluid stream. Furthermore, decoupling on the fluid side can be provided by indirect thermal coupling of at least one fluid flow with a second fluid flow by means of a heat exchanger. In the event of a fault, negative effects on at least one fluid flow as well as on the second fluid flow can thus be avoided in an advantageous manner.

In one embodiment of the magnetic resonance system according to the utility model, the second fluid flow is a forward flow or a return flow of a building heating system.

The second fluid flow can for example represent a forward flow or a return flow of the heating installation. It is particularly conceivable for the second fluid flow to be formed as a return flow of a heating means, such as a hot air heating device, an oil heating device, a heat pump or the like.

The transfer of thermal energy to the return flow of a building heating system has the following advantages: the heat energy of the compressor can be utilized in the heating application without having to provide high temperature levels of the heating application. The temperature difference between the forward flow and the return flow, which has to be provided by the building heating system, is thus advantageously reduced.

Heating systems for buildings can include, for example, oil heating devices, natural gas heating devices, hot water treatment devices, air heating devices, concrete core activation devices, floor heating, and the like. A building heating system can include one or more heating applications dedicated to heating rooms of a building, particularly rooms of research facilities, hospitals, clinics, business and production facilities.

According to a preferred embodiment of the magnetic resonance apparatus of the utility model, the heating application is a low-temperature heating application. The temperature level required for low temperature heating applications is in particular in the temperature range between-15 ℃ and +40 ℃.

The at least one fluid stream can, for example, have a temperature level between 20 ℃ and 60 ℃. Such temperature levels can be used, inter alia, for low temperature heating applications such as floor heating, concrete core activation, air heating and/or preheating of domestic water. The second fluid flow can be a forward flow or a return flow of the low-temperature heating application, which is heated by means of a thermal coupling with at least one fluid flow.

The temperature level required for floor heating and concrete core activation can be, for example, between 18 ℃ and 35 ℃. By adjusting the mass flow of the at least one fluid flow and the second fluid flow by means of suitable means, the thermal energy of the compressor can be used entirely for heating of such a low temperature heating application. At the same time, the low temperature level of the low temperature heating application allows cooling of at least one fluid stream to a temperature level between 18 ℃ and 35 ℃, which is the preferred temperature range for cooling the compressor.

Suitable means for adjusting the mass flow of the at least one fluid flow and the second fluid flow are, for example, mixing valves, pumps, motor valves, regulating valves, etc. The use of such components is known in principle and should not be explained in detail in this connection.

Another low temperature heating application can be, for example, heating a fresh air stream. Depending on the external temperature, the fresh air stream can have a temperature between-15 ℃ and 20 ℃, but can also have a lower or higher temperature. In particular, the low temperature level of the compressor can already be used at lower external temperatures to heat the fresh air flow.

By thermally integrating at least one fluid flow into the low temperature heating application, a high utilization of the heat energy of the compressor can be achieved in an advantageous manner. Thus, the necessity of further cooling the at least one fluid stream to a temperature level required for the compressor by means of the refrigeration facility can be limited or avoided.

In a further embodiment of the magnetic resonance apparatus according to the utility model, the second fluid flow is a substance flow of a primary circuit or a secondary circuit of the heat pump.

Heat pumps are commonly used in low temperature heating applications such as floor heating, concrete core activation, pool heating, and the like. In such a low temperature heating application, the temperature level of at least one fluid flow can also be used advantageously for heating the forward flow or the return flow of the heating application, i.e. the secondary side of the heat pump. In the case of heat pumps with high heating temperatures and/or heating temperatures that fluctuate in accordance with seasons, the heat energy of the compressor can also be used here to heat the primary side of the heat pump. The primary side generally corresponds to the circuit of the heat pump from which heat energy is extracted by means of the heat pump.

By increasing the average temperature in the primary circuit of the heat pump by means of thermal coupling with at least one fluid flow, the efficiency of the heat pump can be increased in an advantageous manner. The coefficient of power (COP, coefficient of performance) of a heat pump is typically dependent on the average temperature difference between the primary and secondary circuits and is increased by increasing the temperature in the primary circuit.

The heat pump can be configured, for example, as an air heat pump, wherein at least one fluid flow is thermally coupled to a fresh air supply of the heat pump by means of a gas-liquid heat exchanger. However, it is also conceivable for the heat pump to be configured as an ice bank heat pump, a groundwater heat pump, a geothermal probe heat pump, a solar collector heat pump, a brine heat pump, etc. In this case, the at least one fluid flow can be coupled to the primary circuit of the heat pump by means of a suitable liquid-liquid or solid-liquid heat exchanger.

In one embodiment of the magnetic resonance apparatus according to the utility model, the second fluid flow is an air flow of a ventilation system, which is configured to provide a regulation of the air flow.

The second fluid flow can be, for example, an air flow of a ventilation system, in particular for fresh air delivery of a building. Depending on the season, the air stream can have a temperature in the range between-20 ℃ and +35 ℃. At least one fluid flow can thus be thermally coupled with the air flow by means of a gas-liquid heat exchanger and advantageously heat or preheat the air flow, in particular at lower external temperatures.

In addition to adjusting the temperature of the air stream, the conditioning of the air stream can also be characterized by dehumidifying (or humidifying) the air stream. During dehumidification, an undesirable amount of water vapor in the air stream is deposited on the cold surface, wherein the temperature of the air stream is generally reduced. Accordingly, the heating of the air flow can be carried out by means of a thermal coupling of the air flow with at least one fluid flow via a gas-liquid heat exchanger, so that the thermal energy of the heating means (or heating rods) is reduced or avoided in an advantageous manner.

By thermally coupling the at least one fluid with the air flow of the ventilation system, the thermal energy of the compressor can be utilized particularly effectively, since the preferred temperature level for cooling the compressor approximately corresponds to the target temperature of the ventilation system for the air conditioning of the building. Furthermore, in the presence of the air dehumidifying function of the ventilation system, the heat energy of the compressor can be used in an advantageous manner for heating the air flow irrespective of the season, since the air in the temperate climate zone must also be dehumidified in warmer seasons.

In a further embodiment of the magnetic resonance apparatus according to the utility model, the second fluid flow is a substance flow of the sub-cooling device, wherein the second fluid flow is thermally coupled to the heating system and/or the ventilation system.

Similar to a heat pump, a refrigeration facility can also have a primary side and a secondary side. The primary-side mass flow is cooled by means of a refrigeration system, while the secondary-side mass flow is heated. The flow of material on the secondary side of the refrigeration system can correspond to the flow of material of the sub-cooling device. The heat energy of the material flow fed to the sub-cooling device can be conducted to the environment by means of the sub-cooling device. The sub-cooling device can be configured in particular as a sub-cooler, cooling tower, air cooler, adiabatic cooler, evaporative cooler, wet cooler or the like.

Preferably, the at least one fluid flow is thermally coupled to the substance flow on the primary side of the refrigeration installation by means of a heat exchanger. The primary-side material flow can form a cooling circuit of a refrigerator of the refrigeration system. The refrigeration system can advantageously be designed to cool the compressor to a predetermined or desired temperature by means of the primary-side mass flow. The at least one fluid stream is also thermally coupled to the mass flow of the sub-cooling device via a thermal coupling to the mass flow on the primary side and a refrigerant circuit of the refrigeration facility.

In one embodiment, the material flow of the sub-cooling device corresponds to the second fluid flow. In this case, the second fluid flow is thermally coupled to the at least one fluid flow via the refrigerant circuit of the refrigerator and the substance flow on the primary side of the refrigeration installation. In this case, the thermal coupling between the at least one fluid flow, the primary-side flow, the refrigerant circuit and the secondary-side flow is preferably achieved by means of a suitable heat exchanger, for example a plate heat exchanger or a tube bundle heat exchanger.

Alternatively, the at least one fluid flow can also be thermally coupled to the material flow of the sub-cooling device by means of a heat exchanger. In this case, it is advantageous to be able to dispense with a refrigerator, since a sub-cooling device with adiabatic cooling and/or evaporative cooling is able to provide a suitable temperature level for the compressor even in case the external temperature exceeds 30 ℃. The mass flow of the sub-cooling device is preferably thermally coupled to the heating application by means of a heat exchanger, so that the heat energy of the compressor can be supplied to the heating application. Since the sub-cooling means generally transfers heat energy to the surrounding air in the outer zone, the second fluid stream is preferably composed of a water-glycol mixture.

The material flow on the secondary side of the refrigeration installation can, for example, have a temperature level of between 25 ℃ and 45 ℃. Preferably, according to the above embodiment, the thermal energy of the secondary-side material flow is used for heating applications.

By using the thermal energy of the material flow of the sub-cooling device, an improved energy efficiency of the magnetic resonance apparatus can be achieved in an advantageous manner, while at the same time a cooling of the compressor to a desired temperature level by the refrigeration facility can be ensured.

According to one embodiment of the magnetic resonance apparatus according to the utility model, the at least one fluid flow and the second fluid flow are thermally coupled to each other by means of a heat exchanger. The heat exchanger is preferably designed according to the embodiment described above.

It is conceivable that the at least one fluid flow and the second fluid flow are thermally coupled by means of a heat exchanger such that thermal energy is transferred between the at least one fluid flow and the second fluid flow via the wall of the heat exchanger.

It is furthermore conceivable that at least one fluid flow is thermally coupled to a third fluid flow by means of a first heat exchanger. The third fluid flow is in turn thermally coupled to the second fluid flow by means of a second heat exchanger such that thermal energy can be transferred from the at least one fluid flow via the third fluid flow to the second fluid flow. Of course, the magnetic resonance apparatus according to the utility model can have a plurality of heat exchangers and/or fluid streams thermally coupling at least one fluid stream with a second fluid stream.

Furthermore, the at least one fluid flow can be thermally coupled with the plurality of second fluid flows by means of a plurality of heat exchangers. It is advantageous if the heat energy of the compressor should be transferred to a plurality of heating applications. In particular, the heat energy of the compressor can therefore always be advantageously fed to the first heating application when the second heating application does not have a heat demand and/or is in seasonal operation.

In a further embodiment, the magnetic resonance system according to the utility model has a bypass, which is designed to provide at least one fluid flow with a flow path that bypasses the heat exchanger.

The bypass can be an alternative flow path that directs at least one fluid stream through the heat exchanger. It is conceivable for the bypass to have fittings, such as valves, mixing valves, motor valves, regulating valves, etc., which are designed to temporarily or permanently close or open the flow path through the bypass.

The pressure loss of the flow path through the bypass can be lower here than the pressure loss of the flow path through the heat exchanger. Thus, when the bypass is open, a substantial portion of at least one fluid flow can be directed through the heat exchanger. However, it is also conceivable for the flow path through the heat exchanger to likewise have a fitting which is designed to close the flow path through the heat exchanger when the bypass valve is opened. Thus, undesired flow through the heat exchanger can be avoided when the bypass is opened.

In a preferred embodiment, the bypass has a controllable valve, in particular a motor valve or a regulating valve. The controllable valve can be configured to adjust or vary the mass flow through the valve in response to a control signal.

In a further embodiment, the magnetic resonance system according to the utility model has at least one control valve and a control unit, wherein the control unit is designed to transmit a control signal to the control valve, wherein the control valve is designed to open or close the bypass in dependence on the control signal.

The regulating valve is preferably designed to close or open the flow path through the bypass in a continuous manner or in discrete steps.

The control unit can have a signal connection to the control unit of the heating application and/or to the monitoring unit of the compressor. It is conceivable that the control unit is designed to receive information about the heat demand, the load level and/or the temperature of the first heating application, the second heating application and/or the compressor by means of the signal connection.

Preferably, the control unit is configured for opening, closing and/or regulating the first regulating valve of the first bypass of the first heat exchanger and/or the second regulating valve of the second bypass of the second heat exchanger as a function of information about the heat demand, the load level and/or the temperature.

The control unit can be designed in particular for actuating or regulating a plurality of control valves in such a way that cooling of the compressor is ensured. For example, the control unit can be designed to actuate a plurality of control valves, but also to actuate the conveyor assembly or the pump such that the temperature of the at least one fluid flow remains within a predetermined range and/or does not exceed a predetermined limit value for the temperature of the at least one fluid flow.

By providing a bypass according to the utility model, a thermal coupling of at least one fluid flow with a second fluid flow of a heating application without heat demand can be avoided in an advantageous manner. In addition, in the case of a plurality of heat exchangers having corresponding bypasses, thermal energy can be advantageously supplied to one or more dedicated heating applications. Another advantage resides in the possibility of: if the functional demand of the heating application is lower than the thermal power of the compressor, at least a portion of the thermal energy of the compressor can be transferred to the cooling circuit of the refrigeration appliance.

According to a further embodiment of the magnetic resonance apparatus of the utility model, the at least one fluid flow is thermally coupled to a cooling circuit of the refrigeration device. The refrigeration facility is configured to provide cooling for a compressor of the magnetic resonance apparatus.

Preferably, the at least one fluid flow is coupled to a cooling circuit of the refrigeration system in addition to the thermal coupling to the one or more heating applications according to the above embodiments. For this purpose, the magnetic resonance apparatus according to the utility model can have a dedicated heat exchanger which enables heat transfer between the at least one fluid flow and the cooling circuit of the refrigeration system. It is furthermore conceivable for the magnetic resonance apparatus to have a bypass according to the above embodiment, which is designed to provide at least one fluid flow with a flow path that bypasses the dedicated heat exchanger.

In a preferred embodiment, the magnetic resonance system has a control unit according to the above-described embodiment. The control unit can be configured in particular for actuating a plurality of control valves and/or conveyor units and for thermally coupling at least one fluid flow to the second fluid flow, the third fluid flow and/or the cooling circuit. Preferably, the control unit is designed to control the mass flow of the at least one fluid flow through the one or more heat exchangers by actuating the one or more control valves and/or the conveyor unit as a function of the temperature of the at least one fluid flow and/or the heat demand of the heating application.

By providing a magnetic resonance system according to the utility model, the use of the thermal energy of the compressor for one or more heating applications can be improved or optimized in an advantageous manner. In particular, the heat energy of the compressor can be utilized to the greatest extent by the heating application while at the same time ensuring sufficient cooling of the compressor by means of the cooling circuit of the refrigeration system.

Drawings

Further advantages and details emerge from the following description of embodiments, in connection with the accompanying drawings. Shown in the schematic diagram:

fig. 1 shows an embodiment of a magnetic resonance system according to the utility model;

figure 2 shows an embodiment of a magnetic resonance apparatus according to the utility model;

fig. 3 shows an embodiment of a magnetic resonance system according to the utility model;

fig. 4 shows an embodiment of a magnetic resonance apparatus according to the utility model with a control unit according to the utility model;

figure 5 shows an embodiment of a magnetic resonance apparatus according to the utility model with a bypass according to the utility model;

fig. 6 shows an embodiment of a magnetic resonance system according to the utility model.

Detailed Description

The magnetic resonance apparatus operates with the aid of a magnetic field. In order to generate a strong basic magnetic field with a field strength of more than 0.5 or 1 tesla, superconducting magnets are generally used. The superconducting magnet is cooled in this case to a temperature of several kelvin. Despite the presence of the most modern insulation, permanent cooling or heat energy removal from the superconducting magnet is still required in order to maintain low temperature levels.

For cooling the superconducting magnet, a cryocooler 13 can be used, which cryocooler 13 achieves a temperature gradient from ambient temperature to liquid helium temperature in one or more stages. However, due to the high temperature gradient, thermodynamic efficiency is so low that a large amount of thermal energy has to be extracted.

In a common embodiment, the cryocooler 13 has a so-called cold head, which is thermally coupled to the superconducting magnet and/or to cryogenic substances in the cryostat 14 of the magnetic resonance device 10. The coldhead is in turn cooled by expansion of the highly compressed cryogenic substance provided by the compressor 13a of the cryocooler 13. The compressor 13a is typically connected to a cooling circuit 16, which cooling circuit 16 absorbs and derives heat energy generated when compressing the cryogenic substances. For this purpose, the compressor 13a can be thermally coupled to the cooling circuit 16 by means of a heat exchanger 50a. Subsystem 17 can have a heat transfer medium that circulates between the heat exchanger of compressor 13a and heat exchanger 50a and transfers the thermal energy of compressor 13a to cooling circuit 16. Subsystem 17 preferably has a pump 15, which pump 15 transfers heat transfer medium between the heat exchanger of the compressor and heat exchanger 50a.

Fig. 1 shows an embodiment of a magnetic resonance apparatus 10 according to the utility model with a cryocooler 13. The field magnet 11 of the magnetic resonance apparatus 10 is arranged in a cryostat 14 for cooling. The field magnet 11 is cooled by the cryocooler 13 so that a superconducting state exists in the field magnet 11.

In the example shown, the cold head 13b of the cryocooler 13 is thermally coupled to the cryogen reservoir 12 and the field magnet 11. Typically, a helium bath (cryogen) with liquid helium forms a cryogen reservoir 12, which cryogen reservoir 12 is cooled by a coldhead 13b and surrounds the superconducting magnet. In the event of failure of the cooling circuit 16, a longer period of time can be spent without external cooling by evaporating liquid helium.

In an alternative embodiment, the magnetic resonance system 10 has only one small coolant reservoir 12 with liquid helium. In this case, the thermal energy of the field magnet 11 is transferred to the cold head 13b without fluid as a heat transfer medium, in particular by thermal conduction via mechanical contact, in particular a heat conducting element or a thermal rail ("thermal bus"). In this case, failure of the cooling circuit 16 must be avoided, since the small refrigerant reservoir 12 has a very limited heat capacity and cooling of the field magnet 11 can only be maintained for a short period of time.

The cooling circuit 16 in fig. 1 has a heat exchanger 50a, which heat exchanger 50a is thermally coupled to the compressor 13a of the cryocooler 13 via the subsystem 17. The heat exchanger 50a is designed in particular for thermally coupling a first fluid flow of the heat transfer medium in the subsystem 17 with a fluid flow of the cooling medium in the cooling circuit 16 in order to conduct away the thermal energy generated at the compressor 13a to the cooling circuit 16. The subsystem 17 separated from the main cooling circuit 16 by the heat exchanger 50a can be regarded as a subsystem of the cooling circuit 16, which requires its own pump 15. Because the compressor 13a is typically operated in an oil-lubricated manner, an oil-based heat transfer medium is suitable for cooling the compressor 13a. However, subsystem 17 can also have other heat transfer media, such as water, water-glycol mixtures, phase change slurries, and the like.

The cooling circuit 16 includes a chiller 30, which chiller 30 continuously cools a return flow 32 of the cooling circuit to a predetermined forward flow temperature. The cooling medium thus cooled is supplied via the forward flow 31 of the cooling circuit 16 to the heat exchangers 50a and 50b in the cooling circuit 16. The heat exchangers 50a and 50b can also be understood as heat sources. In the example shown, the heat source comprises, by way of example, a heat exchanger 50a for the compressor 13a and a heat exchanger 50b for an air conditioning device and/or a cooling device for a gradient coil of the magnetic resonance device 10. The cooling medium in the cooling circuit 16 can for example be water, which is fed by a cold water pump 33 in the cooling circuit 16. However, other cooling or heat transfer media as described above are of course also conceivable.

Fig. 2 shows an embodiment of the magnetic resonance system 10 according to the utility model, in which a first fluid flow of the subsystem 17 is thermally coupled to a second fluid flow of the circuit for the heating application 18 by means of a heat exchanger 50a. The circuits of the heating application 18 can be, for example, a primary side of a heat pump, a secondary side of a heat pump, a heating circuit of a ventilation system, a heating circuit of a floor heating, a heating circuit of a concrete core activation device, and the like. It is also contemplated that the circuit of the heating application 18 is a gas heater, an oil heater, a subsystem for hot water treatment, or the like. Depending on the current heating application 18 and the desired temperature level of the heating application 18, the heat exchanger 50a can be incorporated into the forward flow or return flow of the circuit of the heating application 18.

The circuit for the heating application 18 currently has a heat exchanger 50c, which heat exchanger 50c can be embodied, for example, as a return line for a floor heating, a condenser for a heat pump, a gas-liquid heat exchanger for a ventilation system, a heating body, etc., depending on the heating application. Of course, the circuit of the heating application 18 can have additional components, such as additional flow paths, fittings, check valves, subsystems, conveyor sets, components for pressure maintenance, etc., which are typically required for operating such a heating application 18.

In the example shown in fig. 3, the first fluid flow of subsystem 17 is thermally coupled with the second fluid flow of ventilation system 40 by means of a register 50 d. The second fluid flow can be, for example, a fresh air flow 41, which fresh air flow 41 is sucked from the external area by means of the ventilation system 40. The register 50d is preferably designed as a gas-liquid heat exchanger, for example a laminated heat exchanger. The laminated heat exchanger is configured to transfer thermal energy from the first fluid flow of subsystem 17 to the fresh air flow 41 of ventilation system 40.

The first fluid stream is preferably a water-based heat transfer medium. It is contemplated that compressor 13a is water cooled or has an internal heat exchanger (not shown) that transfers heat energy of the internal oil circuit of compressor 13a to the first fluid stream.

Fig. 4 shows an embodiment of the magnetic resonance apparatus 10 according to the utility model, in which a first fluid flow of the subsystem 17 is thermally coupled to a plurality of second fluid flows of the heating applications 18a, 18b and 18c (18 a-c) by means of a plurality of heat exchangers 50c, 50d and 50e (50 c-e). The heating applications 18a-c here can comprise, for example, a primary circuit of a heat pump, a concrete core activation device and/or an air flow heating device after the air dehumidifying device. In the example shown, the first fluid flow of subsystem 17 is also thermally coupled with the cooling medium of cooling circuit 16 by means of heat exchanger 50 d. By means of the additional thermal coupling to the cooling system 16, it is ensured that the thermal energy of the compressor 13a is led out even when the heating applications 18a-c do not have thermal requirements, are out of operation and/or have a fault condition. Such a fault situation can be, for example, a leak in the heating circuit, but can also be a failure of the sensor and/or the control of the heating application 18.

Preferably, the magnetic resonance apparatus 10 according to the utility model has a control unit 70, which control unit 70 is designed to actuate the control valves 71a, 71b, 71c and 71d (71 a-d) in order to individually set the mass flow of the first fluid flow through the heat exchangers 50 a-d. The control of the control valves 71a-d can take place, for example, on the basis of information about the temperature of the first fluid flow in the compressor 13a and/or in the subsystem 17. The temperature can be detected by means of a suitable sensor (not shown) and transmitted to the control unit 70 via a signal line 72. It is also conceivable that the control unit 70 is connected with sensors and/or control units of the heating applications 50a-50c in order to detect information about the heat demand, the load level and/or the temperature of the fluid flow of the heating applications 50a-50 c. The control unit 70 is designed in particular to set or regulate the mass flow of the first fluid flow through the heat exchangers 50a to 50c as a function of the heat demand and/or the temperature of the heating applications 18a to 18 c. The control unit 70 can also be configured to transfer excess thermal energy in the subsystem 17 to the cooling circuit 16 by means of the heat exchanger 50 d. It is conceivable that subsystem 17 has further conveyor sets 15 and/or regulating valves 71 in order to be able to set the mass flow of the first fluid flow through heat exchangers 50a-d better by means of control unit 70.

Fig. 5 shows a further embodiment of the magnetic resonance apparatus 10 according to the utility model. In the present example, the magnetic resonance apparatus 10 has a bypass 80, the bypass 80 being configured to provide a flow path for the first fluid flow of the subsystem 17 to bypass the heat exchanger 50a. It is contemplated that the heat exchanger 50a thermally couples the first fluid flow with the second fluid flow of the heating application 18 according to one of the examples mentioned above.

The control unit 70 is preferably configured for actuating the regulating valves 71a and 71b (71 a-b) such that the flow path of the first fluid flow through the heat exchanger 50a is closed and the bypass 80 is opened. Thus, if the heating application 18 has too low a heat demand and/or there is a fault condition in the circuit of the heating application 18, the first fluid flow can advantageously bypass the heat exchanger 50a. The circuit of the first fluid flow of the subsystem 17 is advantageously unaffected by the interference due to the separation of the first and second fluid flows by means of the heat exchanger 50a, and the thermal energy of the compressor 13a can be led out via the heat exchanger 50b, which heat exchanger 50b is coupled, for example, with the further heating application 18 and/or the cooling circuit 16. Of course, the control unit is likewise configured for actuating the regulating valves 71a and 71b (71 a-b) such that the flow path of the first fluid flow through the heat exchanger 50a is opened and the bypass 80 is closed.

Fig. 6 shows an embodiment of the magnetic resonance system 10, in which the first fluid flow of the subsystem 17 is thermally coupled to the cooling circuit 16 by means of a heat exchanger 50a. The refrigerator 30 of the cooling circuit 16 currently has a sub-cooling circuit 19 (secondary side of the refrigerator 30) with a sub-cooler 60, which sub-cooler 60 is designed to conduct the thermal energy of the refrigerator 30 to the environment. It is conceivable that the sub-cooling circuit 19 is thermally coupled to the heating application 18 according to the above-described embodiment by means of a heat exchanger 50 c. The heat energy generated in the sub-cooling circuit 19 can thus be advantageously fed to the heating application 18 and at the same time the energy input for the sub-cooling refrigerator 30 can be reduced. In this case, the second fluid flow of the sub-cooling circuit 19 is thermally coupled to the first fluid flow of the subsystem 17 via the heat transfer medium in the internal refrigerant circuit of the refrigerator 30 and the cooling circuit 16. The second fluid stream can in particular have a water-glycol mixture which should have freezing resistance due to the influence of environmental conditions, for example low external temperatures.

Of course, the aspects or features of the individual embodiments of the magnetic resonance apparatus according to the utility model shown in fig. 1 to 6 can be combined with one another. For clarity, detailed illustrations of all possible permutations and combinations are omitted.

While the details of the utility model have been illustrated and described in detail by the preferred embodiments, the utility model is not limited to the examples disclosed and other variants can be derived therefrom by those skilled in the art without departing from the scope of the utility model.

Claims

1. A magnetic resonance apparatus (10), the magnetic resonance apparatus (10) comprising a cryocooler (13) having a compressor, characterized in that the compressor is thermally coupled with at least one fluid flow, and that the at least one fluid flow is configured for absorbing thermal energy from the compressor and delivering the thermal energy to a heating application (18).

2. The magnetic resonance apparatus (10) according to claim 1, wherein the heating application (18) is a low temperature heating application (18), and wherein the temperature level required by the low temperature heating application (18) is in a temperature range between-15 ℃ and +40 ℃.

3. The magnetic resonance apparatus (10) according to claim 2, characterized in that the at least one fluid flow is thermally coupled with a second fluid flow, which second fluid flow is configured for absorbing thermal energy of the at least one fluid flow and delivering it to the heating application (18).

4. A magnetic resonance apparatus (10) according to claim 3, characterized in that the second fluid flow is a forward flow or a return flow of a building heating system.

5. The magnetic resonance apparatus (10) according to any one of claims 3 to 4, characterized in that the second fluid flow is a substance flow of a primary circuit or a secondary circuit of a heat pump.

6. The magnetic resonance apparatus (10) according to any one of claims 3 to 5, characterized in that the second fluid flow is an air flow of a ventilation system (40) configured for providing a regulation of the air flow.

7. A magnetic resonance apparatus (10) according to claim 3, characterized in that the second fluid flow is a substance flow of a sub-cooling device, and wherein the second fluid flow is thermally coupled with a building heating system and/or ventilation system (40).

8. The magnetic resonance apparatus (10) according to any one of claims 3 to 6, characterized in that the at least one fluid flow and the second fluid flow are thermally coupled to each other by means of a heat exchanger (50).

9. The magnetic resonance apparatus (10) according to claim 8, characterized in that the magnetic resonance apparatus (10) further has a bypass (80), the bypass (80) being configured for providing the at least one fluid flow with a flow path bypassing the heat exchanger (50).

10. The magnetic resonance apparatus (10) as claimed in claim 9, characterized in that the magnetic resonance apparatus (10) further has at least one control valve (71) and a control unit (70), wherein the control unit (70) is configured for transmitting a control signal to the control valve (71), wherein the control valve (71) is configured for opening or closing the bypass (80) in dependence on the control signal.

11. The magnetic resonance apparatus (10) according to any one of claims 1 to 10, characterized in that the at least one fluid flow is thermally coupled with a cooling circuit (16) of a refrigeration facility configured for providing cooling for a compressor of the magnetic resonance apparatus (10).