Pumped two-phase cooling system

Abstract

The present invention relates to a pumped two-phase refrigeration system comprising a two-phase working fluid circuit having a first circuit section (2) for directing a first portion of a working fluid to a preheater assembly (4, 4', 4"), the first portion within the first circuit section (2) having a first thermal characteristic; a second circuit section (6) for directing a second portion of the working fluid to the preheater assembly (4), the second portion within the second circuit section (6) having a second thermal characteristic; and a third circuit section (8) for directing a third portion of the working fluid from the preheater assembly (4) to at least one evaporator (10), the third portion within the third circuit section (8) having a third thermal characteristic based on the first thermal characteristic and the second thermal characteristic.

Description

[Technical Field]

[0001] background The present disclosure relates to a pumped two-phase cooling system. [Background technology]

[0002] Pumped two-phase cooling systems utilize the latent heat of vaporization of the working fluid to remove thermal energy from the component being cooled.

[0003] A known pumped two-phase refrigeration system is shown schematically in Figure 1. The system comprises a working fluid circuit 200 for conducting a two-phase working fluid.

[0004] The system further includes a pump 300 for pumping the working fluid through the circuit 200. The system further includes a preheater 400, an evaporator 500, a condenser 600, and a reservoir 100, sometimes referred to as an accumulator. The circuit 200 connects these devices 400, 500, 600, 100 to allow the working fluid to flow through the evaporator 500 and subsequently through the condenser 600. The pump 300 pumps the working fluid through the preheater 400, the evaporator 500, and the condenser 600 in that order.

[0005] The evaporator 500 is configured to cool thermal energy dissipative components, such as power electronic devices, and to this end, the evaporator 500 is positioned and designed to absorb heat from the respective components to be cooled.

[0006] Preheater 400 raises the temperature of the working fluid entering preheater 400 in its liquid phase to its saturation temperature, i.e., to its optimum operating point. Thus, the working fluid enters evaporator 500 at at least essentially its saturation temperature. As such, heat or thermal energy absorbed by the working fluid flowing through evaporator 500 causes a portion of the working fluid to evaporate. Thus, the working fluid exiting evaporator 500 is partially in its liquid phase and partially in its vapor phase.

[0007] The working fluid is then conducted by circuit 200 to condenser 600, where heat is removed from the working fluid, returning it to its liquid phase. Condenser 600 dissipates the heat to the surrounding environment.

[0008] The reservoir 100 is configured to balance the system. To this end, the reservoir 100 stores excess working fluid to compensate for volume changes.

[0009] By using the latent heat of the working fluid, two-phase cooling systems can, in principle, achieve lower pumping power requirements compared to single-phase cooling systems under otherwise identical conditions.

[0010] However, the preheater 400 still requires a certain amount of electrical energy to generate the corresponding heat, which limits the efficiency of the system and therefore its reliability.

[0011] Therefore, there is a need for improved two-phase cooling systems, particularly two-phase cooling systems with improved characteristics related to efficiency and reliability. Summary of the Invention [Means for solving the problem]

[0012] overview According to the present disclosure, a pumped two-phase refrigeration system is provided that includes a two-phase working fluid circuit. The circuit includes a first circuit section for directing a first portion of the working fluid to a preheater assembly. The first section within the first circuit section has a first thermal characteristic. The circuit further includes a second circuit section for directing a second portion of the working fluid to the preheater assembly. The second section within the second circuit section has a second thermal characteristic. The circuit further includes a third circuit section for directing a third portion of the working fluid from the preheater assembly to at least one evaporator. The third section within the third circuit section has a third thermal characteristic based on the first and second thermal characteristics.

[0013] By providing the second circuit, it is possible to supply additional heat energy to the working fluid in the first circuit, i.e., before it enters the evaporator. In this way, it is possible to eliminate the need for a preheater that requires external energy, or at least operate the system using a preheater assembly that requires less energy than the preheaters of the prior art cooling systems described above. In other words, the preheater assembly of the cooling system according to this specification may not require external energy, or at least may require less external energy, compared to the prior art.

[0014] Therefore, less energy is required to operate the cooling system, and two-phase cooling systems can therefore exhibit improved efficiency and therefore improved reliability.

[0015] Various embodiments may implement the following features: The preheater assembly may be configured to heat the working fluid to its saturation temperature, or at least to a temperature close to its saturation temperature. This is generally advantageous with respect to the cooling capacity of the system. In particular, the preheater assembly may be configured to heat the working fluid so that its temperature is at or close to its saturation temperature when it enters the evaporator.

[0016] The term "temperature close to the saturation temperature" is intended to denote a temperature within a certain temperature interval that includes the saturation temperature. The temperature interval may be 6K or 5K or 4K or 3K or 2K.

[0017] The preheater assembly may comprise an electric heating device for heating the working fluid, in this way, for example, the time from starting the system to reaching the optimum temperature of the working fluid upstream of the evaporator can be kept particularly short.

[0018] The circuit may further include a fourth circuit section for conducting a fourth portion of the working fluid from the at least one evaporator to a condenser. The second circuit section may be connected to the fourth circuit section. Upon exiting the evaporator, i.e., in the fourth circuit section, the working fluid has a relatively large amount of thermal energy. Therefore, this thermal energy can be particularly advantageously used to supply the preheater assembly by providing a connection between the fourth circuit section and the second circuit section.

[0019] Thus, the thermal energy "already in the system" can be used by the preheater assembly. The second circuit section can be used to divert a portion of the thermal energy of the working fluid in the fourth circuit section and return it in a specifically controlled manner to the preheater assembly, where it mixes with the "main" flow of the first portion of the working fluid in the first circuit section to heat it.

[0020] The circuit may further comprise a fifth circuit portion for conducting a fifth portion of the working fluid from the condenser to the first circuit portion, the first portion of the working fluid originating from the fifth portion, in this way providing a closed circuit or loop for conducting the working fluid.

[0021] The fifth circuit portion may include a reservoir for the hydraulic fluid, which may be configured to balance the system, for example, by storing excess hydraulic fluid and compensating for volumetric changes of the hydraulic fluid.

[0022] The system may further comprise a pump for pumping the working fluid through the two-phase working fluid circuit, the pump being located, for example, in the fifth circuit part, for example, between the reservoir and the first circuit part.

[0023] The thermal property may include temperature and / or pressure and / or thermal energy. The first thermal property may include the working fluid being in a liquid phase, the second thermal property may include the working fluid being in a partial liquid phase and a partial vapor phase, and the third thermal property may include the working fluid being in a liquid phase. The first thermal property may be different from the third thermal property. Specifically, the third thermal property may include the working fluid containing more energy compared to the first thermal property.

[0024] The system may further include a valve disposed within the second circuit section. The valve allows for influencing the intensity (i.e., volumetric flow rate) of the flow of the working fluid through the second circuit section. In this manner, it is possible to influence the amount of thermal energy supplied to the preheater assembly via the working fluid flowing through the second circuit section. The valve may be a one-way valve.

[0025] The valve may be configured to allow the working fluid to flow from the fourth circuit portion through the second circuit portion to the preheater assembly, and may be further configured to prevent the working fluid from flowing from the preheater assembly through the second circuit portion to the fourth circuit portion, which, in particular, at least essentially prevents heat energy from being extracted from the working fluid in the first circuit portion before the working fluid subsequently enters the evaporator.

[0026] The valve may be configured to control the flow of working fluid from the fourth circuit portion through the second circuit portion to the preheater assembly. In this manner, it is possible to quantitatively determine the amount of thermal energy provided to the first portion of the working fluid, i.e., the working fluid in the first circuit portion.

[0027] The system may further include at least one temperature and / or pressure sensor device for measuring the temperature and / or pressure of the working fluid. The at least one temperature and / or pressure sensor device may be disposed in the first circuit portion and / or the third circuit portion. A temperature or pressure sensor may also or alternatively be provided in the second circuit portion. The temperature or pressure values ​​measured by the temperature and / or pressure sensor device may be particularly advantageously used for improved control of the flow of the working fluid through the second circuit portion.

[0028] To this end, for example, the valve may be configured to operate under the use of temperature and / or pressure information generated or measured by a temperature and / or pressure sensor device.

[0029] The preheater assembly may comprise a junction configured to allow the first portion of the working fluid to mix with the second portion of the working fluid, thus enabling a structurally simple and therefore particularly reliable arrangement for mixing the first portion of the working fluid with the second portion of the working fluid.

[0030] The preheater assembly may further include a coupling circuit portion connecting the junction portion to a third circuit portion. The coupling circuit portion may be, for example, tubular.

[0031] The electrical heating device of the preheater assembly, if provided, may be disposed in the combined circuit section.

[0032] The preheater assembly may further include a heat exchanger connected to the first circuit portion and the second circuit portion and configured to exchange heat between the first portion of the working fluid and the second portion of the working fluid. The heat exchanger allows for improved control of heat exchange between the working fluid originating from the first circuit portion and the working fluid originating from the second circuit portion. The heat exchanger may be configured to exchange heat between the first portion of the working fluid and the second portion of the working fluid without exchanging the working fluid.

[0033] In particular, the working fluid may be arranged to condense in the heat exchanger and give up its thermal energy to the "main fluid" in the form of a first portion of the working fluid flow in the first circuit section, which is then mixed with the "main fluid" downstream of the heat exchanger.

[0034] The system may further comprise an extension circuit portion for directing the working fluid originating from the second circuit portion, after it has passed through the heat exchanger, to a combining circuit portion connecting the first circuit portion to a third circuit portion.

[0035] The system may further include an auxiliary pump for pumping the working fluid from the extension circuit section to the third circuit section. The auxiliary pump may be required depending on the system design and pressure level. However, the auxiliary pump requires significantly less energy than the prior art preheaters described above.

[0036] The preheater assembly may further include a heat exchanger connected to the second circuit portion and to a combining circuit portion connecting the first circuit portion to the third circuit portion, and the heat exchanger may be configured to exchange heat between the working fluid originating from the second circuit portion and the working fluid in the combining circuit portion.

[0037] Here, the working fluid mixes with the "main flow" upstream of the heat exchanger. The system may further include an extension circuit portion for directing the working fluid originating from the second circuit portion, after it has passed through the heat exchanger, to the combination circuit portion at a point between the first circuit portion and the heat exchanger, which may be between the first circuit portion and the pump or between the pump and the preheater assembly.

[0038] Alternatively, the extension circuit portion may be configured to direct the working fluid originating from the second circuit portion to the reservoir after it has passed through a heat exchanger.

[0039] The system may further include an auxiliary pump for pumping hydraulic fluid from the extension circuit portion to the coupling circuit portion or to the reservoir.

[0040] According to an alternative or additional aspect of the present invention, a pumped two-phase refrigeration system is provided, comprising: a reservoir containing a two-phase working fluid; an evaporator; a condenser; and a two-phase working fluid circuit connecting the reservoir, the evaporator, and the condenser and configured to allow the working fluid to flow through the evaporator and past the condenser. The system further comprises a pump configured to pump the working fluid through the circuit and a preheater assembly disposed and configured to preheat the working fluid before entering the evaporator. The circuit comprises a first circuit part configured to allow the working fluid to flow from the evaporator to the condenser, a second circuit part configured to allow the working fluid to flow from the condenser to the evaporator, and a third circuit part connecting the first circuit part to the second circuit part, bypassing the condenser.

[0041] In particular, the present disclosure includes the following aspects: 1. A pumped two-phase cooling system comprising: A two-phase working fluid circuit is provided, a first circuit portion for directing a first portion of the working fluid to the preheater assembly, the first portion within the first circuit portion having a first thermal characteristic; a second circuit portion for directing a second portion of the working fluid to the preheater assembly, the second portion within the second circuit portion having second thermal characteristics; a third circuit portion for directing a third portion of the working fluid from the preheater assembly to the at least one evaporator, the third portion within the third circuit portion having a third thermal characteristic based on the first thermal characteristic and the second thermal characteristic; A pumped two-phase cooling system having:

[0042] 2. The pumped two-phase refrigeration system of aspect 1, wherein the preheater assembly is configured to heat the working fluid to a temperature at or at least close to its saturation temperature.

[0043] 3. The pumped two-phase refrigeration system of aspect 2, wherein the preheater assembly comprises an electric heating device for heating the working fluid.

[0044] 4. The pumped two-phase refrigeration system of any preceding aspect, wherein the two-phase working fluid circuit further comprises a fourth circuit section for directing a fourth portion of the working fluid from the at least one evaporator to a condenser, and the second circuit section is connected to the fourth circuit section.

[0045] 5. The pumped two-phase refrigeration system of aspect 4, wherein the two-phase working fluid circuit further comprises a fifth circuit section for directing a fifth portion of the working fluid from the condenser to the first circuit section, and wherein the first portion of the working fluid originates from the fifth section.

[0046] 6. The pumped two-phase cooling system of aspect 5, wherein the fifth circuit portion comprises a reservoir for the working fluid.

[0047] 7. The pumped two-phase refrigeration system of any preceding embodiment, further comprising a pump for pumping working fluid through the two-phase working fluid circuit.

[0048] 8. The pumped two-phase cooling system of any preceding aspect, wherein the first thermal characteristic includes the working fluid being in a liquid phase, the second thermal characteristic includes the working fluid being in a partial liquid phase and a partial vapor phase, and the third thermal characteristic includes the working fluid being in a liquid phase.

[0049] 9. The pumped two-phase cooling system of any preceding aspect, further comprising a valve disposed in the second circuit portion.

[0050] 10. A pumped two-phase cooling system as described in aspect 9, comprising the features described in aspect 4, wherein the valve is configured to allow the working fluid to flow from the fourth circuit portion through the second circuit portion to the preheater assembly, and further configured to prevent the working fluid from flowing from the preheater assembly through the second circuit portion to the fourth circuit portion.

[0051] 11. The pumped two-phase cooling system of aspect 9 or 10, wherein the valve is configured to control flow of working fluid from the fourth circuit portion through the second circuit portion to the preheater assembly.

[0052] 12. The pumped two-phase refrigeration system of any preceding aspect, further comprising at least one temperature and / or pressure sensor device for measuring a temperature and / or a pressure of the working fluid, wherein the at least one temperature and / or pressure sensor device is disposed within the first circuit portion and / or the third circuit portion.

[0053] 13. A pumped two-phase refrigeration system as described in any of the preceding aspects, comprising the features described in aspects 9 and 12, wherein the valve is configured to operate under use of temperature and / or pressure information generated by the temperature and / or pressure sensor device.

[0054] 14. The pumped two-phase cooling system of any preceding aspect, wherein the preheater assembly comprises a junction configured to allow a first portion of the working fluid to mix with a second portion of the working fluid.

[0055] 15. The pumped two-phase cooling system of aspect 14, wherein the preheater assembly further comprises a coupling circuit portion connecting the junction portion to a third circuit portion.

[0056] 16. A pumped two-phase cooling system as described in aspect 15, comprising the features of aspect 3, wherein the electric heating device is disposed in the combined circuit portion.

[0057] 17. The pumped two-phase cooling system of any of aspects 1-13, wherein the preheater assembly further comprises a heat exchanger connected to the first circuit portion and the second circuit portion and configured to exchange heat between the first portion of the working fluid and the second portion of the working fluid.

[0058] 18. The pumped two-phase refrigeration system of embodiment 17, further comprising an extension circuit portion for directing the working fluid originating from the second circuit portion after it has passed through the heat exchanger to a combining circuit portion connecting the first circuit portion to a third circuit portion.

[0059] 19. The pumped two-phase cooling system of embodiment 18, further comprising an auxiliary pump for pumping the working fluid from the extension circuit portion to the third circuit portion.

[0060] 20. The pumped two-phase cooling system of any of aspects 1-13, wherein the preheater assembly further includes a heat exchanger connected to the second circuit section and a combined circuit section connecting the first circuit section to the third circuit section, the heat exchanger configured to exchange heat between the working fluid originating from the second circuit section and the working fluid in the combined circuit section.

[0061] 21. The pumped two-phase refrigeration system of aspect 20, further comprising an extension circuit portion for directing the working fluid originating from the second circuit portion after it has passed through the heat exchanger to the combined circuit portion at a point between the first circuit portion and the heat exchanger.

[0062] 22. The pumped two-phase cooling system of embodiment 21, further comprising an auxiliary pump for pumping the working fluid from the extension circuit portion to the combination circuit portion.

[0063] 23. The pumped two-phase cooling system of embodiment 20, further comprising an extension circuit portion for directing the working fluid originating from the second circuit portion to the reservoir after it has passed through the heat exchanger.

[0064] 24. The pumped two-phase cooling system of embodiment 23, further comprising an auxiliary pump for pumping the working fluid from the extension circuit portion to the reservoir.

[0065] 25. A pumped two-phase cooling system, preferably according to any one of the preceding embodiments, comprising: a reservoir containing a two-phase working fluid; an evaporator; A condenser; a two-phase working fluid circuit connecting the reservoir, the evaporator, and the condenser and configured to allow a working fluid to flow through the evaporator and the condenser; a pump configured to pump the hydraulic fluid through the circuit; a preheater assembly arranged and configured to preheat the working fluid before it enters the evaporator; Equipped with The circuit is a first circuit part configured to allow the working fluid to flow from the evaporator to the condenser; a second circuit part configured to allow the working fluid to flow from the condenser to the evaporator; a third circuit part connecting the first circuit part and the second circuit part, bypassing the condenser; A pumped two-phase cooling system.

[0066] 26. The pumped two-phase refrigeration system of aspect 25, wherein the pump is configured to pump the working fluid through the condenser and the reservoir, in that order.

[0067] 27. The pumped two-phase cooling system of any of aspects 25-26, wherein the pump is configured to pump the working fluid through the preheater and the evaporator, in that order.

[0068] 28. A pumped two-phase refrigeration system according to any of aspects 25 to 27, wherein the third circuit part constitutes a return line for allowing the working fluid to return from the first circuit part to the second circuit part upstream of the evaporator.

[0069] 29. The pumped two-phase cooling system of any of aspects 25-28, wherein the third circuit part is connected to the second circuit part at a junction so as to allow a portion of the working fluid to flow from the third circuit part to the second circuit part at the junction.

[0070] 30. The pumped two-phase refrigeration system of aspect 29, further comprising a mixing arrangement disposed at the junction and configured to control a mixing ratio between a flow of working fluid flowing from the third circuit part to the second circuit part and a further flow of working fluid flowing from a first portion of the second circuit part upstream of the junction to a second portion of the second circuit part downstream of the junction.

[0071] 31. The pumped two-phase cooling system of any of aspects 25-30, wherein the third circuit part is connected to the second circuit part at a preheater assembly.

[0072] 32. The pumped two-phase cooling system of any one of aspects 25-31, further comprising a valve disposed in the third circuit part.

[0073] 33. The pumped two-phase cooling system of aspect 32, wherein the valve is configured to allow the working fluid to flow from the first circuit part through the third circuit part to the second circuit part, and is further configured to prevent the working fluid from flowing from the second circuit part through the third circuit part to the first circuit part.

[0074] 34. The pumped two-phase cooling system of any of aspects 25 to 33, further comprising at least one temperature and / or pressure sensor device disposed in the second circuit part or the third circuit part and configured to measure the temperature or pressure of the working fluid.

[0075] 35. The pumped two-phase refrigeration system of embodiment 34, wherein the at least one temperature and / or pressure sensor device is disposed between the pump and the preheater assembly or between the preheater assembly and the evaporator.

[0076] 36. A pumped two-phase refrigeration system as described in embodiment 35, comprising at least two temperature and / or pressure sensor devices, a first of the at least two temperature and pressure sensor devices being disposed between the pump and the preheater assembly, and a second of the at least two temperature and / or pressure sensor devices being disposed between the preheater assembly and the evaporator.

[0077] 37. The pumped two-phase cooling system of any of aspects 25-36, further comprising a heat exchanger arranged and configured to exchange heat between at least a portion of the working fluid in the third circuit part and at least a further portion of the working fluid in the second circuit part.

[0078] 38. The pumped two-phase cooling system of embodiment 37, wherein the heat exchanger is disposed adjacent to or within the preheater assembly.

[0079] 39. The pumped two-phase cooling system of aspect 37 or 38, further comprising an additional pump configured to pump working fluid from the third circuit part to the second circuit part.

[0080] 40. The pumped two-phase cooling system of embodiment 39, wherein an additional pump is disposed in a third circuit part between the heat exchanger and the second portion of the second circuit part.

[0081] 41. The pumped two-phase refrigeration system of any one of aspects 37 to 40, wherein the third circuit part connects to the second circuit part between the heat exchanger and the evaporator.

[0082] 42. A pumped two-phase cooling system according to any one of aspects 37 to 40, wherein the third circuit part is connected to the second circuit part between the reservoir and the pump or between the pump and the heat exchanger.

[0083] 43. The pumped two-phase refrigeration system of any one of aspects 25 to 42, wherein the third circuit part connects to the second circuit part between the condenser and the reservoir.

[0084] BRIEF DESCRIPTION OF THE DRAWINGS The subject matter of the present disclosure will now be described in more detail with reference to preferred exemplary embodiments thereof as illustrated in the accompanying drawings. [Brief explanation of the drawings]

[0085] [Figure 1] FIG. 1 is a schematic diagram of a prior art pumped two-phase cooling system. [Figure 2] 1 is a schematic diagram of a pumped two-phase cooling system according to a first embodiment; [Figure 3] FIG. 1 is a schematic diagram of a pumped two-phase cooling system according to a second embodiment. [Figure 4] FIG. 10 is a schematic diagram of a pumped two-phase cooling system according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0086] Detailed Description 2 is a schematic diagram of a pumped two-phase cooling system according to a first embodiment. The cooling system comprises a two-phase working fluid circuit for conducting a two-phase working fluid.

[0087] The system further includes a pump 20, a preheater assembly 4, an evaporator 10, and a condenser 14. The pump 20 is configured to pump the working fluid through the circuit. Specifically, the system is configured such that the working fluid can be pumped by the pump 20 through the circuit passing through the evaporator 10 and the condenser 14.

[0088] The system shown in Figure 2 shows an exemplary system having only one evaporator 10. However, the system may also include multiple evaporators, which may be connected, for example, in series or in parallel.

[0089] Additionally, the system includes a reservoir 18 for balancing the system. The circuit includes a first circuit portion 2, a second circuit portion 6, and a third circuit portion 8. The first circuit portion 2 is configured to direct a first portion of the working fluid to the preheater assembly 4. The second circuit portion 6 is configured to direct a second portion of the working fluid to the preheater assembly 4. The third circuit portion 8 is configured to direct a third portion of the working fluid from the preheater assembly 4 to an evaporator 10.

[0090] A first portion of the working fluid has a first thermal property that includes the working fluid being in a liquid phase, a second portion of the working fluid has a second thermal property that includes the working fluid being partially in a liquid phase and partially in a vapor phase, and a third portion of the working fluid has a third thermal property that includes the working fluid being in a liquid phase.

[0091] The third thermal characteristic is based on the first thermal characteristic and the second thermal characteristic. The preheater assembly 4 includes a junction 22 configured to allow a first portion of the working fluid to mix with a second portion of the working fluid. In other words, the working fluid originating from the first circuit portion 2 and the working fluid originating from the second circuit portion 6 mix at the junction 22 within the preheater assembly 4. As a result, the thermal energy of the working fluid exiting the preheater assembly 4, i.e., the third portion of the working fluid, is based on or dependent on the first thermal characteristic and the second thermal characteristic. The third thermal characteristic further depends on the first volumetric flow rate at which the first portion of the working fluid reaches the junction 22 and the second volumetric flow rate at which the second portion of the working fluid reaches the junction 22.

[0092] The preheater assembly 4 further includes a coupling circuit portion 24 connecting the junction 22 to the third circuit portion 8, thereby allowing the working fluid to flow from the junction 22 through the coupling circuit portion 24 to the third circuit portion 8.

[0093] The preheater assembly 4 is configured to heat the working fluid to, or at least close to, its saturation temperature.

[0094] The circuit further comprises a fourth circuit part 12 for conducting a fourth portion of the working fluid from the evaporator 10 to the condenser 14. In other words, the fourth circuit part 12 connects the evaporator 10 with the condenser 14 so that the working fluid can flow from the evaporator 10 to the condenser 14.

[0095] The second circuit portion 6 is connected to the fourth circuit portion 12. In other words, one end of the second circuit portion 6 enters the preheater assembly 4 and the other opposite end of the second circuit portion 6 is fluidly connected to the fourth circuit portion 12.

[0096] The circuit further comprises a fifth circuit part 16 for conducting a fifth portion of the working fluid from the condenser 14 to the first circuit part 2. In other words, the fifth circuit part 16 connects the condenser 14 with the first circuit part 2 so that the working fluid can flow from the condenser 14 to the first circuit part 2.

[0097] The reservoir 18 and / or the pump 20 may be disposed within the fifth circuit portion 16, as exemplarily shown in FIG.

[0098] The preheater assembly 4 may include an electric heating device for heating the working fluid. The heating device may be arranged and positioned to heat the working fluid in the combined circuit section 24, i.e., between the junction 22 and the evaporator 10. In this way, if the working fluid downstream of the junction 22 does not yet have the desired temperature for entering the evaporator 10, the working fluid can be heated by the electric heating device to its saturation temperature, or at least to a temperature close to its saturation temperature. This may be particularly advantageous during the initial stages after the system has been started up, as long as the average temperature of the working fluid is not yet at an equilibrium level.

[0099] The system may further include a valve 26 disposed within the second circuit portion 6. The valve 26 may be configured to allow working fluid to flow from the fourth circuit portion 12 through the second circuit portion 6 to the preheater assembly 4. The valve 26 may be configured to prevent working fluid from flowing from the preheater assembly 4 through the second circuit portion 6 to the fourth circuit portion 12.

[0100] Valve 26 may further be configured to control the flow, i.e., volumetric flow, of working fluid from fourth circuit portion 12 through second circuit portion 6 to preheater assembly 4. In this manner, the amount of thermal energy supplied to preheater assembly 4 by the working fluid in second circuit portion 6 can be adjusted.

[0101] The system may further comprise at least one temperature and / or pressure sensor device 30, 32 for measuring the temperature and / or pressure of the working fluid. The at least one temperature and / or pressure sensor device 30, 32 may be arranged, for example, in the first circuit part 2 and / or in the third circuit part 8. The temperature or pressure measured by the temperature and / or pressure sensor device 30, 32 can advantageously be used for improved control of the thermal properties of the working fluid.

[0102] In particular, the valve 26 may be configured to operate under the use of temperature and / or pressure information generated by the temperature and / or pressure sensor devices 30,32.

[0103] FIG. 3 is a schematic diagram of a pumped two-phase cooling system according to a second embodiment. Unless otherwise stated below, the above description of the first embodiment also applies to the other embodiments, and reference numerals are used similarly.

[0104] The preheater assembly 4' according to the second embodiment comprises a heat exchanger 34 connected to the first circuit portion 2 and the second circuit portion 6. The preheater assembly 34 is configured to exchange heat between a first portion of the working fluid and a second portion of the working fluid. The system further comprises an extension circuit portion 36 for directing the working fluid originating from the second circuit portion 6, after it has passed through the heat exchanger 34, to a combining circuit portion 38 connecting the first circuit portion 2 to the third circuit portion 8.

[0105] Additionally, the system further comprises an auxiliary pump 40 for pumping hydraulic fluid from the extension circuit portion 36 to the third circuit portion 8 .

[0106] The auxiliary pump 40 may be configured to operate only when necessary. Due to the arrangement of the second circuit portion 6 and the extension circuit portion 36, the auxiliary pump 40 can in principle be expected to require less energy than a corresponding pump according to the prior art as described above.

[0107] FIG. 4 is a schematic diagram of a pumped two-phase cooling system according to a third embodiment. The preheater assembly 4″ according to the third embodiment further comprises a heat exchanger 42 connected to the second circuit section 6 and to a combining circuit section 44 connecting the first circuit section 2 to the third circuit section 8. The heat exchanger 42 is configured to exchange heat between the working fluid originating from the second circuit section 6 and the working fluid in the combining circuit section 44.

[0108] The system further comprises an extension circuit portion 46 for directing the working fluid originating from the second circuit portion 6, after it has passed through the heat exchanger 42, to the combined circuit portion 44 at a point 48 between the first circuit portion 2 and the heat exchanger 42. The point 48 may be, for example, between the first circuit portion 2 and the pump 2, or, for example, between the pump 20 and the heat exchanger 42. Alternatively, the extension circuit portion may be configured to direct the working fluid originating from the second circuit portion 6, after it has passed through the heat exchanger 42, to the reservoir 18.

[0109] The system further includes an auxiliary pump 50 for pumping hydraulic fluid from the extension circuit portion 46 to the coupling circuit portion 44 or to the reservoir 18. The auxiliary pump 50 may be configured to operate only when needed. Due to the arrangement of the second circuit portion 6 and the extension circuit portion 46, the auxiliary pump 40 can in principle be expected to require less energy than corresponding pumps according to the prior art, as described above.

[0110] While the present disclosure has been illustrated and described in detail in the drawings and the foregoing description, such illustration and description should be considered illustrative or exemplary and non-limiting. Other variations of the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed subject matter, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements, and the indefinite articles "a" or "an" do not exclude a plurality. The mere fact that certain elements or steps are recited in separate claims does not indicate that a combination of these elements or steps cannot be advantageously employed; specifically, any further meaningful combination of claims should be considered disclosed, in addition to the actual claim dependencies.

Claims

1. 1. A pumped two-phase cooling system comprising: a two-phase working fluid circuit, the two-phase working fluid circuit comprising: a first circuit portion (2) for directing a first portion of a working fluid to a preheater assembly (4, 4', 4"), the first portion within the first circuit portion (2) having a first thermal characteristic; a second circuit portion (6) for directing a second portion of the working fluid to the preheater assembly (4), the second portion within the second circuit portion (6) having second thermal characteristics; a third circuit portion (8) for conducting a third portion of the working fluid from the preheater assembly (4) to at least one evaporator (10), the third portion within the third circuit portion (8) having a third thermal characteristic based on the first thermal characteristic and the second thermal characteristic; A pumped two-phase cooling system having:

2. 2. The pumped two-phase refrigeration system of claim 1, wherein the two-phase working fluid circuit further comprises a fourth circuit portion (12) for conducting a fourth portion of the working fluid from the at least one evaporator (10) to a condenser (14), and the second circuit portion (6) is connected to the fourth circuit portion (12).

3. 3. The pumped two-phase refrigeration system of claim 2, wherein the two-phase working fluid circuit further comprises a fifth circuit portion (16) for conducting a fifth portion of the working fluid from the condenser (14) to the first circuit portion (2), and the first portion of the working fluid originates from the fifth portion.

4. 4. The pumped two-phase cooling system of claim 3, wherein the fifth circuit portion (16) comprises a reservoir (18) for the working fluid.

5. 10. A pumped two-phase cooling system according to any preceding claim, further comprising a pump (20) for pumping said working fluid through said two-phase working fluid circuit.

6. 10. A pumped two-phase cooling system according to any of the preceding claims, further comprising a valve (26), preferably a one-way valve, arranged in the second circuit part (6).

7. 7. The pumped two-phase cooling system of claim 6, comprising the features of claim 2, wherein the valve (26) is configured to allow the working fluid to flow from the fourth circuit portion (12) through the second circuit portion (6) to the preheater assembly (4) and is further configured to prevent the working fluid from flowing from the preheater assembly (4, 4′, 4″) through the second circuit portion (6) to the fourth circuit portion (12).

8. 8. The pumped two-phase cooling system of claim 6 or 7, wherein the valve (26) is configured to control the flow of the working fluid from the fourth circuit portion (12) through the second circuit portion (6) to the preheater assembly (4, 4', 4").

9. 10. A pumped two-phase cooling system according to any of the preceding claims, further comprising at least one temperature and / or pressure sensor device (30, 32) for measuring the temperature and / or pressure of the working fluid, said at least one temperature and / or pressure sensor device (30, 32) being arranged in said first circuit part (2) and / or in said third circuit part (8).

10. 10. A pumped two-phase cooling system as claimed in any preceding claim, comprising the features of claims 6 and 9, wherein the valve (26) is configured to operate under the use of temperature and / or pressure information generated by the temperature and / or pressure sensor device (30, 32).

11. 10. The pumped two-phase cooling system of any preceding claim, wherein the preheater assembly (4) comprises a junction (22) configured to allow the first portion of the working fluid to mix with the second portion of the working fluid.

12. the preheater assembly (4') further comprises a heat exchanger (34) connected to the first circuit portion (2) and the second circuit portion (6) and configured to exchange heat between the first portion of the working fluid and the second portion of the working fluid; 11. A pumped two-phase cooling system according to any one of claims 1 to 10, wherein the system further comprises an extension circuit portion (36) for directing the working fluid originating from the second circuit portion (6) after it has passed through the heat exchanger (34) to a combining circuit portion (38) connecting the first circuit portion (2) to the third circuit portion (8).

13. 13. The pumped two-phase cooling system of claim 12, further comprising an auxiliary pump (40) for pumping the working fluid from the extension circuit portion (36) to the third circuit portion (8).

14. The preheater assembly (4") further comprises a heat exchanger (42) connected to the second circuit portion (6) and a combination circuit portion (44) connecting the first circuit portion (2) to the third circuit portion (8), the heat exchanger (42) being configured to exchange heat between the working fluid originating from the second circuit portion (6) and the working fluid in the combination circuit portion (44); Aspect 11. The pumped two-phase cooling system of any of aspects 1-10, wherein the system further comprises an extension circuit portion (46) for directing the working fluid originating from the second circuit portion (6) after it has passed through the heat exchanger (42) to the combination circuit portion (44) at a point (48) between the first circuit portion (2) and the heat exchanger (42).

15. The pumped two-phase cooling system of claim 14, further comprising an auxiliary pump (50) for pumping the working fluid from the extension circuit portion (46) to the combination circuit portion (44).

Images