COMPACT COOLING SYSTEM AND METHOD FOR ACCURATE TEMPERATURE CONTROL

Description

Field of the Present Invention

[0001] The present invention relates to a compact and structurally simple cooling system and cooling method, in particular to a two-phase cooling system and cooling method for evaporative CO₂ cooling with high temperature accuracy.

Background and Relevant State of the Art

[0002] Carbon dioxide (CO₂) cooling was widespread in the late 19^th century and early 20^th century before being replaced by synthetic refrigerants, but is now again gaining increasing attention for many applications in science and technology, ranging from fridges and air-conditioning, in particular for motor vehicles, to ice-skating rings and cooling of detector equipment for high energy physics experiments. A manifold range of applications, both old and new, is described by A. Pearson, "Carbon Dioxide - New Uses for an Old Refrigerant", International Journal of Refrigeration 28 (2005) 1140 -1148.

[0003] CO₂ cooling is attractive because it offers the combination of high heat transfer coefficients (one order of magnitude higher than traditional refrigerants) with low mass cooling structures. In addition, CO₂ has a relatively high evaporation pressure, so that the vapor volumes remain small, resulting in small diameter tubing. CO₂ also has a large latent heat of evaporation, which allows for a reduced fluid flow and even smaller tubing diameters. Since CO₂ cannot exist as a liquid under atmospheric pressure, any leak or spilling of CO₂ will lead to immediate vaporization of the leaked CO₂, and will not harm the equipment by a liquid spill. This is a clear advantage over conventional liquid refrigerants, and makes CO₂ a good choice for cooling sensitive objects or objects placed in sensitive environments, such as for the temperature control of scientific equipment inside clean laboratories.

[0004] In summary, CO₂ cooling allows for an accurate thermal control of distant setups with only small additional cooling hardware, which is a frequent desire in many high-tech applications today.

[0005] A conventional two-phase accumulator controlled loop (2PACL) evaporative CO₂ cooling system 100 as employed for the LHCb-VELO experiment at CERN and described in further detail in B. Verlaat et al., "CO2 Cooling for the LHCb-VELO Experiment at CERN", 8th IIF/IIR Gustav Lorentzen Conference on Natural Working Fluids 2008, Copenhagen, CDP 16-T3-08 is schematically shown in Fig. 1. This cooling system 100 comprises an accumulator vessel 102 for storing a supply of CO₂ in a liquid and vapor mixture. The CO₂ boiling pressure is controlled using a combination of heating and cooling, wherein heating is achieved by means of an electrical heater such as a thermo siphon heater 104, and cooling of the supply of CO₂ in the accumulator vessel 102 can be performed by employing an integrated cooling spiral 106 connected to an external chiller 108.

[0006] The external chiller 108 also serves to sub-cool the refrigerant in the condenser 110, which is in fluid communication both with the accumulator vessel 102 and a liquid pump 112. The chiller 108 remains always cooler than the accumulator 102 saturation temperature, and this is needed to provide subcooled liquid inside the pump 112 From the liquid pump 112, the subcooled refrigerant is supplied to a heat exchanger 114, where the liquid refrigerant is pre-heated to the saturation temperature by bringing it into thermal contact with a return pipe 116 comprising CO₂ in a mixed liquid/vapor phase returning from the object to be cooled. After having been pre-heated by means of the heat exchanger 114, liquid CO₂ 118 with a temperature that corresponds to the boiling temperature of the return pipe 116 is supplied to an evaporator (not shown) in thermal contact with the experiment to be cooled. The pressure drop towards the evaporator causes the supplied liquid to boil in the evaporator and realizes a direct temperature control of the attached experiment via the system pressure regulated in the accumulator 102 . After thermal interaction with the object to be cooled, the refrigerant returns to the cooling system 100 via the return pipe 116, and is channeled through the heat exchanger 114 to the condenser 110, whereupon the cooling cycle begins anew.

[0007] The cooling cycle and operation of the conventional 2PACL system is further illustrated in the pressure-enthalpy phase diagram of Fig. 2. The sub-cooled liquid (1) is pumped into the system by means of the liquid pump 112 (1-2). The internal heat exchanger (2-3) 114 heats up the pumped sub-cooled liquid to the saturation temperature of the evaporator, causing the inlet of the evaporator always to be saturated after liquid injecting (point 4 within the two-phase zone of the pressure-enthalpy diagram). Point 4 after expansion 3-4 in the phase diagram of Fig. 2 designates the moment when the fluid starts boiling due to the initial temperature setting of the liquid temperature in point 3. The fluid state in the evaporator is two-phase, and nearly independent of the absorbed heat. The independence of the heat absorption is ideal for scientific experiments as a temperature control under loaded and unloaded conditions is often demanded The pressure drop between the evaporator (4-5) and the accumulator connection (1) is low, and hence the accumulator 102 directly controls the pressure and hence temperature of the evaporator.

[0008] The conventional CO₂ evaporative cooling system as described with reference to Figs. 1 and 2 allows for an accurate (isothermal) and direct temperature control of even distant objects to be cooled, and does not require any active components near the object. Tubes of very small diameter are sufficient to provide the refrigerant to the evaporator, possibly over very long transfer lines, while all the active hardware may be placed in a distant cooling plant which can be made easy accessible. This is particularly advantageous for high energy physics experiments, in which the cooling plant is in general far away from the detector device to be cooled, and local control or monitoring of the cooling at the detector device is usually unfeasible due to the high levels of radiation encountered there.

[0009] However, a reliable operation of the conventional system shown in Fig. 1 requires that the refrigerant supplied to the liquid pump 112 is carefully kept sub-cooled in order to avoid any cavitation that could interfere with the pumping. The system hence requires a careful control of the temperature and pressure in the accumulator vessel 102 and the inlet pipe of the pump 112. In the configuration shown in Fig. 1, this can be achieved by means of a programmable logic control unit 120 which governs the operation of both the electric heater 104 and the cooling spiral 106 in response to the user-required evaporator temperature or temperature at the inlet of the liquid pump 112 in case sub cooling is insufficient (measured by means of a temperature gauge 122) and the pressure in the accumulator vessel 102 (measured by means of a pressure gauge 124). Since proper operation of the cooling system 100 crucially depends on a careful and delicate control of the pressure and temperature, the system is rather complex and expensive. Moreover, a complex external chiller 108 is needed both for cooling of the accumulator vessel 102 and for cooling of the condenser 110, sometimes causing both cooling actions to interfere with each other. Together with the associated piping, the chiller 108 adds to the complexity and size of the system.

[0010] As a result, conventional C0₂ evaporative cooling systems to date are bigger, more complex and more expensive than competing systems relying on thermostatic baths, such as cooling systems employing liquid water, glycol or silicone oil. This may be why, in spite of their superior performance, evaporative C0₂ cooling systems have so far been limited to specific applications and have not yet realized their full potential.

[0011] What is needed, therefore, is an evaporative cooling system that is compact, structurally simple and does not require any sophisticated control.

[0012] US6866092 discloses a cooling system according to the preamble of claim 1 and various improvements to two-phase cooling systems.

Overview of the Present Invention

[0013] These objectives are achieved with a cooling system and cooling method according to independent claims 1 and 10, respectively. The dependent claims relate to preferred embodiments.

[0014] It is the insight of the inventor that a more compact cooling system that is easier to control can be achieved by dispensing with a separate external heat exchanger (as described with reference to Fig. 1), and instead providing an outlet fluid path from the liquid pump in thermal contact with said accumulator, in particular with said supply of refrigerant stored in said accumulator. Refrigerant flowing through said outlet fluid path may then exchange heat with said accumulator, in particular to cool said supply of refrigerant stored in said accumulator and/or to heat up said refrigerant in said outlet fluid path.

[0015] In the configuration according to the present invention, the accumulator may hence be cooled by the discharge liquid of the pump, which is always warmer than the saturation temperature of the refrigerant at the pump inlet. This provides a self-regulation that prevents the accumulator from becoming cooler than the saturation temperature of the pump inlet, and hence automatically preserves the sub-cooling level needed to guarantee uninterrupted operation of the liquid pump, without requiring external sub-cooling control by means of a programmable logic control unit.

[0016] At the same time, the thermal contact of the outlet fluid path with the accumulator allows to set the temperature of the outgoing refrigerant to the accumulator temperature. This ensures that the refrigerant is set to boiling temperature for delivery to the object to be cooled.

[0017] In a cooling system according to the present invention, the accumulator in thermal contact with the outlet fluid path integrates the functionalities of a standard accumulator and an external heat exchanger of a conventional 2PACL cooling system. The cooling system according to the present invention thus allows dispensing both with a separate heat exchanger and a complex PLC controller, and is hence structurally simpler, smaller and easier to build.

[0018] According to a preferred embodiment, the outlet fluid path traverses said accumulator or contacts said accumulator.

[0019] Preferably, the cooling system comprises a heat exchanger adapted for exchanging heat with said accumulator, said heat exchanger arranged in said outlet fluid path.

[0020] Preferably, said heat exchanger comprises a cooling spiral in fluid communication with said outlet fluid path, said cooling spiral arranged in said accumulator.

[0021] These provisions allow for an efficient heat exchange between the supply of refrigerant stored in said accumulator and said outlet fluid path.

[0022] In a preferred embodiment, the cooling system further comprises a chiller or external cold source thermally connected to said condenser, so to cool said refrigerant in said inlet fluid path.

[0023] Preferably, said chiller or external cold source is not thermally connected to said accumulator.

[0024] In a preferred embodiment, said system is adapted to cool said supply of refrigerant stored in said accumulator exclusively through thermal contact of the refrigerant vapor with said outlet fluid path. Preferably, said accumulator is not connected to an external cooling source.

[0025] It is the insight of the inventor that the system according to the present invention allows cooling the supply of refrigerant in said accumulator efficiently merely by way of heat exchange with said outlet fluid path and refrigerant vapor. The accumulator does not need to be connected to an external chiller or cooling source, which reduces the complexity and size of the overall cooling system.

[0026] The accumulator may merely comprise a heating unit for regulating the boiling pressure of the refrigerant by boiling the liquid content in the accumulator. The heating unit may comprise a thermo siphon heater for an efficient contact to the liquid phase. Without a heating unit, the boiling pressure would only be regulated by the outlet fluid path temperature and hence the external chiller temperature. By providing a heating unit, the boiling pressure in the accumulator may be controlled with a better accuracy.

[0027] According to this latter embodiment, the accumulator comprises a heating unit adapted for heating said supply of refrigerant to a predetermined pressure or temperature, in particular to a predetermined boiling temperature or saturation temperature by evaporating the liquid content.

[0028] Said accumulator may be adapted to adjust a temperature of said refrigerant in said outlet fluid path to a predetermined temperature, in particular to raise the temperature of said refrigerant to said predetermined temperature, in particular to a boiling temperature of said refrigerant, by way of said thermal contact of said accumulator with said outlet fluid path.

[0029] Said outlet fluid path may be adapted to supply said refrigerant to an object to be cooled after exchanging heat with said accumulator.

[0030] Said inlet fluid path may be adapted to receive said refrigerant from said object after cooling said object.

[0031] The cooling system according to the present invention may be an evaporative cooling system, in particular a two-phase evaporative cooling system. Preferably, said refrigerant is or comprises CO₂, but other refrigerants may be employed as well.

[0032] In a preferred embodiment, said system further comprises a control unit adapted to control said heating unit and/or said liquid pump, preferably in response to a temperature and/or a pressure measured in said inlet fluid path and/or in said accumulator.

[0033] The present invention likewise relates to a method for cooling an object according to claim 10.

[0034] In a preferred embodiment, the method comprises a step of regulating a boiling pressure of said refrigerant by adjusting a pressure and/or a temperature of said supply of refrigerant in said accumulator.

[0035] Preferably, the method comprises a step of adjusting a pressure and/or a temperature of said supply of refrigerant in said accumulator by heating said supply by means of a heating unit.

[0036] In a preferred embodiment, the method comprises a step of adjusting a pressure and/or a temperature of said supply of refrigerant in said accumulator by cooling said supply with said pumped refrigerant.

[0037] Preferably, said supply of refrigerant in said accumulator is cooled exclusively with said pumped refrigerant.

[0038] In a preferred embodiment, the method comprises a step of channeling said pumped refrigerant through said accumulator.

[0039] In a preferred embodiment, the method comprises a step of adjusting a temperature of said pumped refrigerant to a predetermined temperature, in particular to a boiling temperature of said refrigerant, by means of said thermal contact with said supply of refrigerant in said accumulator. In particular, the method comprises the step of raising said temperature of said pumped refrigerant to said predetermined temperature.

[0040] According to a preferred embodiment, the method comprises the step of receiving said refrigerant from said object to be cooled, and providing or supplying said received refrigerant to said condenser.

[0041] The method according to any of these embodiments may employ a cooling system with some or all of the features as described above.

[0042] The invention further relates to a data storage device adapted to store computer-readable instructions, such that said computer-readable instructions, when read on a computer connected to a cooling system with some or all of the features as described above, implement on said cooling system a method with some or all of the features as described above.

Description of Preferred Embodiments

[0043] The features and numerous advantages of the present invention will be best understood from a detailed description of the preferred embodiments in conjunction with the accompanying figures, in which:

Fig. 1

schematically shows a conventional two-phase accumulator controlled loop cooling system;

Fig. 2

shows a pressure-enthalpy phase diagram illustrating the cooling cycle in a conventional two-phase accumulator controlled loop cooling system as shown in Fig. 1; and

Fig 3

schematically shows an integrated two-phase accumulator controlled loop cooling system according to an embodiment of the present invention.

[0044] The invention will now be described for the specific example of a two-phase evaporative CO₂ cooling system that improves on, but is otherwise similar in design and functionality to the conventional 2PACL CO₂ cooling system described above with reference to Figs. 1 and 2.

[0045] The integrated 2PACL cooling system 200 shown in Fig. 3 comprises an accumulator vessel 202 that is similar in design to the accumulator vessel 102 described above with reference to Fig. 1. In particular, the accumulator vessels 202 comprises an electrical heater 204, such as a thermo siphon heater, for heating and hence evaporating a supply of refrigerant 206 stored in the accumulator vessel 202, as well as a cooling spiral 208 for cooling and hence condensing said supply of refrigerant 206.

[0046] The accumulator vessel 202 is connected, via a branch line 210, to an inlet fluid pipe or inlet fluid tube 212 in which a condenser 214 is provided. In the context of the present invention, the terms "pipe" and "tube" may be used interchangeably. The condenser 214 shown in Fig. 3 is generally identical or similar to the condenser 110 described previously with reference to the 2PACL cooling system of Fig. 1 and may be any condenser as conventionally employed in cooling systems.

[0047] The condenser 214 is connected, via an input line 216 and an output line 218, to an external chiller 220. The external chiller 220 may be any conventional chiller as employed in cooling systems or any other cold source, and in general may be similar to the external chiller 108 described with reference to the conventional 2PACL system of Fig. 1. However, in contrast to the configuration of Fig. 1, the external chiller 220 is merely connected to the condenser 214, and does not also serve to cool the accumulator vessel 202. Compared to the external chiller 108, the external chiller 220 according to the present invention may hence be smaller, and the amount of piping may also be reduced. No interference between the multiple cooling connections is present anymore.

[0048] The condenser 214 serves to sub-cool the CO₂ supplied to the condenser 214 from the accumulator vessel 202 via the branch line 210 and inlet fluid pipe 212. Sub-cooled CO₂ leaves the condenser 214 and is supplied, still via the inlet fluid pipe 212, to an inlet 222 of a liquid pump 224. The liquid pump 224 may be similar to the liquid pump 112 described with reference to Fig. 1, and can in general be any pump suitable for pumping liquid CO₂ (or other fluids if used instead of CO₂ in the invention). An outlet 226 of the liquid pump 224 is connected to an outlet fluid pipe 228, which supplies the pumped CO₂ to an object to be cooled (not shown).

[0049] On its way to the object to be cooled, the pumped CO₂ traverses the cooling spiral 208 provided in the accumulator vessel 202, and hence exchanges heat with the supply of refrigerant 206 stored in said accumulator vessel 202. The outlet fluid path can hence be subdivided into two sections, a first section 228a connecting the outlet 226 of the liquid pump 224 to an inlet of the cooling spiral 208, and a second section 228b downstream from an outlet of the cooling spiral 208. In operation, the accumulator vessel 202 will in general be filled with saturated liquid and vapor, and hence the pumped CO₂ in the outlet fluid pipe 228 will have been heated up to the accumulator temperature once it reaches the outlet of the accumulator cooling spiral 208. At this stage, the fluid is still supplied via the outlet fluid pipe 228 and is not yet boiling, although its temperature now coincides with the temperature of the boiling fluid in the accumulator vessel 202, or nearly so. This is due to the higher pressure in the outlet fluid pipe 228. The liquid CO₂ at boiling temperature is then supplied to an evaporator (not shown) in thermal contact with the object to be cooled. Once the liquid CO₂ at boiling temperature reaches the evaporator, the pressure is lowered and the fluid starts boiling, thereby cooling the object.

[0050] The integrated 2PACL according to the present invention is nearly isotherm during boiling from the evaporator to the inlet of the liquid pump. Only the pressure drop in this part of the system causes a small temperature gradient, much smaller than in systems using a liquid cooling flow. In the latter systems, the liquid flow is difficult to control as it is subject to heating during transfer. Local sensor control may be employed, but will usually lead to the system having a low response time. In contrast, the system according to the present invention controls the distant temperature by controlling the pressure, which is transmitted with the speed of sound, and hence almost without any delay.

[0051] CO₂ in a mixed liquid/vapor phase returns from the object to be cooled and is channeled through the inlet fluid pipe 212 to the condenser 214 for subsequent cooling, and hence the cooling cycle is closed.

[0052] In particular, when illustrated in a pressure-enthalphy phase diagram, the cooling cycle of the integrated two-phase accumulator controlled loop cooling system according to the embodiment of Fig. 3 is generally identical to the cooling cycle of a conventional 2PACL cooling system, and hence reference may be made to the phase diagram of Fig. 2.

[0053] The functionality of the cooling system according to the embodiment of Fig. 3 is in general very similar to the conventional 2PACL cooling system known from the art.

[0054] However, in the invention, the cooling of the supply of refrigerant 206 stored in said accumulator vessel 202 is achieved exclusively by means of thermal contact with the pumped refrigerant via the cooling spiral 208, and no external cooling of the accumulator vessel 202 is required. In operation, the CO₂ boiling pressure in the accumulator vessel 202 is controlled solely by means of heating via the electrical heater 204. A control unit 230 controls operation of the electrical heater 204 in response to a pressure in the accumulator vessel 202 detected by means of a pressure gauge 232. Since the control unit 230 is needed solely for controlling the electrical heater 204, it does not require a complex programmable logic control such as the control unit 120 described with reference to Fig. 1.

[0055] Cooling the supply of refrigerant 206 in the accumulator vessel 202 by means of the discharge liquid of the pump 224 has the additional advantage that the accumulator temperature cannot fall below the temperature of the discharge liquid of the pump, which is higher than the saturation temperature at the pump inlet 222. In this way, the sub-cooling of the pump is guaranteed by the laws of nature, and the risk of evaporation of the refrigerant in the liquid pump 224 is avoided without any additional sub-cooling control, which conventionally also had to be provided by the programmable logic control unit 120.

[0056] The invention hence results in a two-phase evaporative CO₂ cooling system that is structurally simpler, more reliable, better to control and cheaper to build, but without compromising on the functionality of a conventional 2PACL system. The integrated 2PACL cooling system according to the present invention is similar in complexity and price to conventional cooling systems employing thermostatic baths, but has the additional advantage of accurate (isothermal) and direct temperature control on distant experiments in combination with very small cooling tubes.

[0057] The description of the preferred embodiments and the figures merely serve to illustrate the invention and the beneficial effects associated therewith, but should not be understood to imply any limitation. The scope of the invention is to be determined solely based on the appended set of claims.

Reference Signs

[0058] 

100

2PACL cooling system

102

accumulator vessel

104

electrical heater

106

cooling spiral

108

external chiller or cold source

110

condenser

112

liquid pump

114

heat exchanger

116

return pipe

118

liquid CO₂ with the same temperature as the boiling temperature in the accumulator

120

programmable logic control unit

122

temperature gauge

124

pressure gauge

200

integrated 2PACL cooling system

202

accumulator vessel

204

electrical heater

206

supply of refrigerant

208

cooling spiral

210

branch line

212

inlet fluid pipe

214

condenser

216

input line of condenser 214

218

output line of condenser 214

220

external chiller or cold source

222

inlet of liquid pump 224

224

liquid pump

226

outlet of liquid pump 224

228

outlet fluid pipe

228a

first section of outlet fluid pipe 228

228b

second section of outlet fluid pipe 228

230

control unit

232

pressure gauge

Claims

1. A cooling system (200) comprising:

a liquid pump (224) having an inlet (222) and an outlet (226), said liquid pump (224) adapted for pumping a liquid refrigerant;

an inlet fluid path (212) for said refrigerant, said inlet fluid path (212) connected to said inlet of said liquid pump (224);

an accumulator (202) adapted for storing a supply (206) of said refrigerant, said accumulator (202) being in fluid communication with said inlet fluid path (212);

a condenser (214) adapted for cooling said refrigerant, said condenser (214) arranged in said inlet fluid path (212) between said accumulator (202) and said inlet (222) of said liquid pump (224); and

an outlet fluid path (228) for said refrigerant, said outlet fluid path (228) connected to said outlet (226) of said liquid pump (224);

wherein part of said outlet fluid path (228) is in thermal contact with said accumulator (202) so to allow said refrigerant flowing through said outlet fluid path (228) to exchange heat with said accumulator (202), characterised in that said refrigerant within the part of said outlet fluid path (228) in thermal contact with said accumulator (202) is not in fluid contact with the supply of refrigerant in said accumulator (202).

2. The cooling system (200) according to claim 1, wherein said outlet fluid path (228) traverses said accumulator (202) or contacts said accumulator (202).

3. The cooling system (200) according to claim 1 or 2, further comprising a heat exchanger (208) adapted for exchanging heat with said accumulator (202), said heat exchanger (208) arranged in said outlet fluid path (228), wherein said heat exchanger preferably comprises a cooling spiral (208) in fluid communication with said outlet fluid path (228), said cool- ing spiral (208) arranged in said accumulator (202).

4. The cooling system (200) according to any of the preceding claims, further comprising a chiller or an external cold source (220) connected to said condenser (214), wherein preferably said chiller or external cold source (220) is not thermally connected to said accumulator (202).

5. The cooling system (200) according to any of the preceding claims, wherein said system (200) is adapted to cool said supply (206) of refrigerant stored in said accumulator (202) exclusively through thermal contact with said outlet fluid path (228), and said accumulator (202) is not thermally connected to an external cooling source.

6. The cooling system (200) according to any of the preceding claims, wherein said accumulator (202) comprises a heating unit (204) adapted for heating said supply (206) of refrigerant to a predetermined pressure or temperature, in particular to a predetermined boiling temperature.

7. The cooling system (200) according to any of the preceding claims, wherein said accumulator (202) is adapted to adjust a temperature of said refrigerant in said outlet fluid path (228) to a predetermined temperature, in particular to a boiling temperature of said refrigerant in the said accumulator, by means of said thermal contact of said accumulator (202) with said outlet fluid path (228).

8. The cooling system (200) according to any of the preceding claims, wherein said cooling system (200) is a two-phase cooling system and said refrigerant comprises

9. The cooling system (200) according to claim 6, or either of claims 7 or 8 when dependent on claim 6, further comprising a control unit (230) adapted to control said heating unit (204) preferably in response to a temperature and/or a pressure measured by respective sensors (122,124) in said inlet fluid path (212) and/or in said accumulator (202).

10. A method for cooling an object, comprising the steps of:

providing a supply (206) of a refrigerant in an accumulator (202) at a predetermined temperature and/or at a predetermined pressure;

supplying at least part of said refrigerant to a condenser (214) for sub-cooling said refrigerant;

supplying said sub-cooled refrigerant to a liquid pump (224); and

establishing a thermal contact of said pumped refrigerant with said accumulator (202) to allow said pumped refrigerant to exchange heat with said supply (206) of refrigerant in said accumulator (202); and

subsequently supplying said pumped refrigerant to said object to be cooled, wherein said pumped refrigerant in thermal contact with the accumulator is not in fluid contact with the supply of refrigerant in said accumulator.

11. The method according to claim 10, further comprising a step of regulating a boiling pressure of said refrigerant by adjusting a pressure and/or temperature of said supply (206) of refrigerant in said accumulator (202).

12. The method according to claim 10 or 11, further comprising a step of adjusting a pressure and/or temperature of said supply (206) of refrigerant in said accumulator (202) by heating said supply (206) by means of a heating unit (204).

13. The method according to any of the claims 10 to 12, further comprising a step of channelling said pumped refrigerant through said accumulator (202).

14. The method according to any of the claims 10 to 13, employing a cooling system (200) according to any of the claims 1 to 9.

15. A data storage device adapted to store computer-readable instructions, such that said computer-readable instructions, when read on a computer connected to a cooling system (200) according to any of the claims 1 to 9, implement on said cooling system (200) a method according to any of the claims 10 to 14.

Ansprüche

1. Kühlsystem (200), umfassend:

eine Flüssigkeitspumpe (224), die einen Einlass (222) und einen Auslass (226) aufweist, wobei die Flüssigkeitspumpe (224) zum Pumpen eines flüssigen Kältemittels geeignet ist;

einen Einlassfluidweg (212) für das Kältemittel, wobei der Einlassfluidweg (212) mit dem Einlass der Flüssigkeitspumpe (224) verbunden ist;

einen Akkumulator (202), der zum Speichern einer Zufuhr (206) des Kältemittels geeignet ist, wobei der Akkumulator (202) in Fluidverbindung mit dem Einlassfluidweg (212) steht;

einen Kondensator (214), der zum Kühlen des Kältemittels geeignet ist, wobei der Kondensator (214) in dem Einlassfluidweg (212) zwischen dem Akkumulator (202) und dem Einlass (222) der Flüssigkeitspumpe (224) angeordnet ist; und

einen Auslassfluidweg (228) für das Kältemittel, wobei der Auslassfluidweg (228) mit dem Auslass (226) der Flüssigkeitspumpe (224) verbunden ist;

wobei ein Teil des Auslassfluidweges (228) in thermischem Kontakt mit dem Akkumulator (202) steht, um es dem durch den Auslassfluidweg (228) fließenden Kältemittel zu ermöglichen, Wärme mit dem Akkumulator (202) auszutauschen, dadurch gekennzeichnet, dass das Kältemittel innerhalb des Teils des Auslassfluidweges (228), der in thermischem Kontakt mit dem Akkumulator (202) steht, nicht in Fluidkontakt mit der Zufuhr an Kältemittel in dem Akkumulator (202) steht.

2. Kühlsystem (200) nach Anspruch 1, wobei der Auslassfluidweg (228) den Akkumulator (202) durchquert oder den Akkumulator (202) kontaktiert.

3. Kühlsystem (200) nach Anspruch 1 oder 2, ferner umfassend einen Wärmetauscher (208), der zum Austauschen von Wärme mit dem Akkumulator (202) geeignet ist, wobei der Wärmetauscher (208) in dem Auslassfluidweg (228) angeordnet ist, wobei der Wärmetauscher vorzugsweise eine Kühlspirale (208) in Fluidverbindung mit dem Auslassfluidweg (228) umfasst, wobei die Kühlspirale (208) in dem Akkumulator (202) angeordnet ist.

4. Kühlsystem (200) nach einem der vorhergehenden Ansprüche, ferner umfassend einen Kühler oder eine externe Kältequelle (220), die mit dem Kondensator (214) verbunden ist, wobei vorzugsweise der Kühler oder die externe Kältequelle (220) nicht thermisch mit dem Akkumulator (202) verbunden ist.

5. Kühlsystem (200) nach einem der vorhergehenden Ansprüche, wobei das System (200) geeignet ist, um die Zufuhr (206) von dem in dem Akkumulator (202) gespeicherten Kältemittel ausschließlich durch thermischen Kontakt mit dem Auslassfluidweg (228) zu kühlen, und wobei der Akkumulator (202) nicht thermisch mit einer externen Kühlquelle verbunden ist.

6. Kühlsystem (200) nach einem der vorhergehenden Ansprüche, wobei der Akkumulator (202) eine Wärmeeinheit (204) umfasst, die geeignet ist, um die Zufuhr (206) von Kältemittel auf eine(n) zuvor bestimmten Druck oder Temperatur zu erwärmen, insbesondere auf eine zuvor bestimmte Siedetemperatur.

7. Kühlsystem (200) nach einem der vorhergehenden Ansprüche, wobei der Akkumulator (202) geeignet ist, eine Temperatur des Kältemittels in dem Auslassfluidweg (228) auf eine zuvor bestimmte Temperatur, insbesondere auf eine Siedetemperatur des Kältemittels in dem Akkumulator, mittels des thermischen Kontakts des Akkumulators (202) mit dem Auslassfluidweg (228) einzustellen.

8. Kühlsystem (200) nach einem der vorhergehenden Ansprüche, wobei das Kühlsystem (200) ein Zwei-Phasen-Kühlsystem ist und wobei das Kältemittel CO₂ umfasst.

9. Kühlsystem (200) nach Anspruch 6 oder nach einem der Ansprüche 7 oder 8, wenn abhängig von Anspruch 6 ist, ferner umfassend eine Steuereinheit (230), die geeignet ist, die Wärmeeinheit (204) vorzugsweise als Reaktion auf eine Temperatur und/oder einen Druck zu steuern, die/der von entsprechenden Sensoren (122, 124) in dem Einlassfluidweg (212) und/oder in dem Akkumulator (202) gemessen wird.

10. Verfahren zum Kühlen eines Objekts, umfassend die folgenden Schritte:

Bereitstellen einer Zufuhr (206) eines Kältemittels in einem Akkumulator (202) bei einer zuvor bestimmten Temperatur und/oder bei einem zuvor bestimmten Druck;

Zuführen wenigstens eines Teils des Kältemittels zu einem Kondensator (214) zum Unterkühlen des Kältemittels;

Zuführen des unterkühlten Kältemittels zu einer Flüssigkeitspumpe (224); und

Herstellen eines thermischen Kontakts des gepumpten Kältemittels mit dem Akkumulator (202), um es dem gepumpten Kältemittel zu ermöglichen, Wärme mit der Zufuhr (206) des Kältemittels in dem Akkumulator (202) auszutauschen; und

anschließendes Zuführen des gepumpten Kältemittels zu dem zu kühlenden Objekt, wobei das gepumpte Kältemittel in thermischem Kontakt mit dem Akkumulator nicht in Fluidkontakt mit der Zufuhr des Kältemittels in dem Akkumulator steht.

11. Verfahren nach Anspruch 10, ferner umfassend einen Schritt des Regulierens eines Siededrucks des Kältemittels durch Einstellen eines Drucks und/oder einer Temperatur der Zufuhr (206) des Kältemittels in dem Akkumulator (202).

12. Verfahren nach Anspruch 10 oder 11, ferner umfassend einen Schritt des Einstellens eines Drucks und/oder einer Temperatur der Zufuhr (206) von Kältemittel in dem Akkumulator (202) durch Erwärmen der Zufuhr (206) mittels einer Wärmeeinheit (204).

13. Das Verfahren nach einem der Ansprüche 10 bis 12, ferner umfassend einen Schritt des Leitens des gepumpten Kältemittels durch den Akkumulator (202).

14. Verfahren nach einem der Ansprüche 10 bis 13, ferner umfassend das Verwenden eines Kühlsystems (200) nach einem der Ansprüche 1 bis 9.

15. Datenspeichervorrichtung, die zum Speichern von computerlesbaren Anweisungen derart geeignet ist, dass die computerlesbaren Anweisungen, wenn sie auf einem an ein Kühlsystem (200) angeschlossenen Computer nach einem der Ansprüche 1 bis 9 gelesen werden, in dem Kühlsystem (200) ein Verfahren nach einem der Ansprüche 10 bis 14 ausführen.

Revendications

1. Système de refroidissement (200) comprenant :

une pompe à liquide (224) ayant une entrée (222) et une sortie (226), ladite pompe à liquide (224) étant conçue pour pomper un réfrigérant liquide ;

un trajet de fluide d'entrée (212) pour ledit réfrigérant, ledit trajet de fluide d'entrée (212) étant relié à ladite entrée de ladite pompe à liquide (224) ;

un accumulateur (202) conçu pour stocker une alimentation (206) dudit réfrigérant, ledit accumulateur (202) étant en communication fluidique avec ledit trajet de fluide d'entrée (212) ;

un condenseur (214) conçu pour refroidir ledit réfrigérant, ledit condenseur (214) étant disposé dans ledit trajet de fluide d'entrée (212) entre ledit accumulateur (202) et ladite entrée (222) de ladite pompe à liquide (224) ; et

un trajet de fluide de sortie (228) pour ledit réfrigérant, ledit trajet de fluide de sortie (228) étant relié à ladite sortie (226) de ladite pompe à liquide (224) ;

une partie dudit trajet de fluide de sortie (228) étant en contact thermique avec ledit accumulateur (202) de manière à permettre audit réfrigérant de s'écouler à travers ledit trajet de fluide de sortie (228) pour échanger la chaleur avec ledit accumulateur (202), caractérisé en ce que ledit réfrigérant à l'intérieur de la partie dudit trajet de fluide de sortie (228) en contact thermique avec ledit accumulateur (202) n'est pas en contact fluidique avec l'alimentation en réfrigérant dans ledit accumulateur (202).

2. Système de refroidissement (200) selon la revendication 1, dans lequel ledit trajet de fluide de sortie (228) traverse ledit accumulateur (202) ou entre en contact avec ledit accumulateur (202).

3. Système de refroidissement (200) selon la revendication 1 ou 2, comprenant en outre un échangeur de chaleur (208) conçu pour échanger de la chaleur avec ledit accumulateur (202), ledit échangeur de chaleur (208) étant disposé dans ledit trajet de fluide de sortie (228), ledit l'échangeur de chaleur comprenant de préférence une spirale de refroidissement (208) en communication fluidique avec ledit trajet de fluide de sortie (228), ladite spirale de refroidissement (208) étant disposée dans ledit accumulateur (202).

4. Système de refroidissement (200) selon l'une quelconque des revendications précédentes, comprenant en outre un refroidisseur ou une source froide externe (220) relié(e) audit condenseur (214), ledit refroidisseur ou ladite source froide externe (220) n'étant de préférence pas relié(e) thermiquement audit accumulateur (202).

5. Système de refroidissement (200) selon l'une quelconque des revendications précédentes, dans lequel ledit système (200) est conçu pour refroidir ladite alimentation (206) en réfrigérant stockée dans ledit accumulateur (202) exclusivement par contact thermique avec ledit trajet de fluide de sortie (228) et ledit accumulateur (202) n'est pas relié thermiquement à une source de refroidissement externe.

6. Système de refroidissement (200) selon l'une quelconque des revendications précédentes, dans lequel ledit accumulateur (202) comprend une unité de chauffage (204) conçue pour chauffer ladite alimentation (206) en réfrigérant à une pression ou une température prédéterminée, en particulier à une température d'ébullition prédéterminée.

7. Système de refroidissement (200) selon l'une quelconque des revendications précédentes, dans lequel ledit accumulateur (202) est conçu pour régler une température dudit réfrigérant dans ledit trajet de fluide de sortie (228) à une température prédéterminée, en particulier à une température d'ébullition dudit réfrigérant dans ledit accumulateur, au moyen dudit contact thermique dudit accumulateur (202) avec ledit trajet de fluide de sortie (228).

8. Système de refroidissement (200) selon l'une quelconque des revendications précédentes, dans lequel ledit système de refroidissement (200) est un système de refroidissement diphasique et ledit réfrigérant comprend du CO₂.

9. Système de refroidissement (200) selon la revendication 6, ou l'une des revendications 7 ou 8 lorsqu'elle dépend de la revendication 6, comprenant en outre une unité de commande (230) conçue pour commander ladite unité de chauffage (204) de préférence en réponse à une température et/ou une pression mesurée par des capteurs respectifs (122, 124) dans ledit trajet de fluide d'entrée (212) et/ou dans ledit accumulateur (202).

10. Procédé de refroidissement d'un objet, comprenant les étapes :

de fourniture d'une alimentation (206) en réfrigérant dans un accumulateur (202) à une température prédéterminée et/ou à une pression prédéterminée ;

de fourniture d'au moins une partie dudit réfrigérant à un condenseur (214) pour sous-refroidir ledit réfrigérant ;

de fourniture dudit réfrigérant sous-refroidi à une pompe à liquide (224) ; et

d'établissement d'un contact thermique dudit réfrigérant pompé avec ledit accumulateur (202) pour permettre audit réfrigérant pompé d'échanger de la chaleur avec ladite alimentation (206) en réfrigérant dans ledit accumulateur (202) ; et

de fourniture ultérieure dudit réfrigérant pompé audit objet à refroidir, ledit réfrigérant pompé en contact thermique avec l'accumulateur n'étant pas en contact fluidique avec l'alimentation en réfrigérant dans ledit accumulateur.

11. Procédé selon la revendication 10, comprenant en outre une étape de régulation d'une pression d'ébullition dudit réfrigérant en ajustant une pression et/ou une température de ladite alimentation (206) en réfrigérant dans ledit accumulateur (202).

12. Procédé selon la revendication 10 ou 11, comprenant en outre une étape de réglage d'une pression et/ou d'une température de ladite alimentation (206) en réfrigérant dans ledit accumulateur (202) en chauffant ladite alimentation (206) au moyen d'une unité de chauffage (204).

13. Procédé selon l'une quelconque des revendications 10 à 12, comprenant en outre une étape de canalisation dudit réfrigérant pompé à travers ledit accumulateur (202).

14. Procédé selon l'une quelconque des revendications 10 à 13, utilisant un système de refroidissement (200) selon l'une quelconque des revendications 1 à 9.

15. Dispositif de stockage de données conçu pour stocker des instructions lisibles par ordinateur, de sorte que lesdites instructions lisibles par ordinateur, lorsqu'elles sont lues sur un ordinateur connecté à un système de refroidissement (200) selon l'une quelconque des revendications 1 à 9, mettent en œuvre sur ledit système de refroidissement (200) un procédé selon l'une quelconque des revendications 10 à 14.

Drawing