COOLING UNIT FOR A HEAT EXCHANGER

Description

Technical field

[0001] The invention relates to a cooling unit for a heat exchanger integrated in an oxygenator for controlling the temperature of blood conducted in an extracorporeal blood circuit, with a storage container storing a liquid, a reaction container comprising a reactant which, in conjunction with the liquid, is capable of initiating an endothermic reaction, a functional means generating fluidic access between the storage container and the reaction container, and a fluid line running at least partially within the reaction container, which fluid line has an inlet and outlet line which can each be connected or are connected in a fluid-tight manner to a hose line system of the heat exchanger, and which forms at least part of a fluid circuit with the hose line system of the heat exchanger. State of the art

[0002] It is known that the heat or cold released during exothermic or endothermic chemical reactions can be used for technical purposes through heat coupling. For endothermic reactions in which cold is released, there are numerous applications, which are briefly outlined below.

[0003] In cardiac surgery or intensive care medicine, particularly for the treatment of acute heart and / or lung failure, heart-lung machines are used to replace the pumping function of the heart and lung function for a limited period of time. The blood leaves the body via an extracorporeal blood circuit in the form of a system of tubes, is enriched with oxygen with the help of an oxygenator, which is part of the heart-lung machine, and then returned to the body. The oxygenator takes over the function of the lungs and not only supplies the blood with vital oxygen, but also removes the carbon dioxide (CO2) produced by metabolic processes.

[0004] All oxygenators in use today also have a heat exchanger, which allows the flowing blood to be warmed and, more importantly, cooled. For example, cardiac procedures are usually performed under hypothermic conditions, meaning the blood is cooled to a greater or lesser extent. Lowering body temperature reduces cellular metabolic activity and increases the ischemia tolerance of the affected tissues and organs.

[0005] So-called hypothermia devices serve as cooling sources. These devices typically generate chilled water as the coolant and use it to cool the blood flowing through the oxygenator via a heat exchanger, i.e., to specifically extract its thermal energy. Commercially available hypothermia devices are large and heavy, usually mounted on casters, with heating and cooling units powered by mains electricity, making them unsuitable for field use.

[0006] Modern hypothermia devices, thanks to their compact design and largely autonomous power and cooling water supply, allow for portable use, independent of an electrical power and water supply. Such hypothermia devices provide fluid-tight connections for a heat exchanger integrated into the oxygenator, allowing them to be used modularly or integrated with an oxygenator.

[0007] The principle of cold generation in these largely autonomous, modern hypothermia devices is based on an endothermic chemical reaction, usually between ammonium nitrate, calcium ammonium nitrate, or urea and water. Urea is often used as a chemical component in cold packs to generate a rapid cooling effect. These typically consist of two separate compartments, one containing urea and the other water. If the separation is removed, the urea dissolves in the water. Since the lattice energy of urea is greater than the hydration energy, the dissolution process extracts energy from the surroundings and cools them. See Robert T. Sataloff: Sataloff's Comprehensive Textbook of Otolaryngology. Jaypee Brothers, 2016, ISBN 978-93-5152745-9, p. 412.

[0008] The publication US 2014 / 0371552 A1 discloses a blood glucose measuring device that can be non-invasively applied to the skin surface of a patient and comprises a cooling device, a temperature measuring device, and an infrared radiation detector. For the purpose of blood glucose measurement, the skin surface is lowered to a predetermined temperature using the cooling device, and the infrared radiation emitted or absorbed by the skin surface is measured. The cooling device consists of two fluid-tight and directly adjacent chambers, one of which is filled with urea and the other with water. With the aid of a spring-loaded mandrel, a partition wall that fluid-tightly separates the two chambers can be locally perforated so that the water flows into the urea chamber, thereby initiating an endothermic reaction that extracts heat energy from the environment and cools the skin surface to be measured in a predetermined manner.

[0009] A device for temperature control based on a chemical reaction and its use as a temperature control unit for a heat exchanger is described in the document DE 10 2017 211 671 A1. The known device uses a container partially filled with granular urea, into which a second container filled with water and with a deformable container wall is inserted. For cooling purposes, the water flows from the second container into the first container and reacts with the urea, forming a positive reaction enthalpy that can be used industrially through heat coupling.

[0010] The document EP 3 079 737 B1 discloses a cooling unit for a heat exchanger integrated in an oxygenator, in which a chemical reaction of zeolite as a sorbent and water serves as the cooling source. Description of the invention

[0011] The invention is based on the object of designing a cooling unit for a heat exchanger integrated in an oxygenator for controlling the temperature of blood conducted in an extracorporeal blood circuit, with a storage container storing a liquid, a reaction container comprising a reactant which, in conjunction with the liquid, is able to initiate an endothermic reaction, a functional means generating fluidic access between the storage container and the reaction container, and a fluid line running at least partially within the reaction container, which has an inlet and outlet line which can each be connected or are connected in a fluid-tight manner to a hose line system of the heat exchanger, and which forms at least part of a fluid circuit with the hose line system of the heat exchanger, as compact, lightweight and autonomously operating as possible in order to enable manually portable use.The cooling unit should be implemented using the simplest and most cost-effective means possible, and it should also allow for the design of at least modular components as disposable products. The amount of heat or cold released by the device should be provided in the shortest possible time, thus generating the greatest possible cooling or heating output.

[0012] The solution to the problem underlying the invention is specified in claim 1. Features that advantageously form the cooling unit according to the solution are the subject of the subclaims and the further description, in particular with reference to the illustrated embodiment.

[0013] The cooling unit according to the invention according to the features of the preamble of claim 1 is characterized in that an equalizing tank with an overflow is provided, into which the liquid flows from the storage tank after fluidic access has been created between the storage tank and the reaction tank. The fluidic access is created by means of a functional means capable of locally perforating or opening the storage tank. The overflow represents a fluid connection to the reaction tank, through which a portion, preferably the majority, of the stored liquid enters the reaction tank to initiate the endothermic reaction with the reactant, preferably in the form of granular urea. The fluid line is fluidically connected to the equalizing tank, into which the remaining portion of the stored liquid flows from the storage tank.The residual portion of the stored liquid is understood to mean that portion of the liquid that does not flow into the reaction vessel due to the arrangement geometry of the overflow relative to the capacity of the equalizing tank. To prevent the liquid that has entered the reaction vessel through the overflow from flowing back into the equalizing tank, a check or non-return valve is preferably arranged along the fluid connection of the overflow. In addition, a fluid pump located outside the reaction vessel is arranged along the fluid line, which runs at least partially inside the reaction vessel. By means of the fluid pump, the liquid is sucked from the equalizing tank into the fluid line that runs at least partially inside the reaction vessel.

[0014] The fluid line, which runs at least partially within the reaction vessel, further runs fluid-tight through the reaction vessel wall delimiting the reaction vessel to the outside and forms a fluid line section, which is referred to below as the discharge line and is designed in the form of a flexible hose line. The fluid line running inside the reaction vessel is made at least in sections from metal, preferably from aluminum, to optimize heat transfer to the surrounding medium within the reaction vessel. In order to ensure the largest possible heat transfer contact surface between the fluid line and the liquid present inside the reaction vessel, the path of the fluid line inside the reaction vessel is selected to be as long as possible. For this purpose, the fluid line running inside the reaction vessel is preferably designed to be helical or coil-shaped, at least in sections.

[0015] A fluid pump is arranged along the discharge line leading out of the reaction vessel. It is preferably designed in the form of a roller pump. By means of a peristaltic pressure applied externally to the tubing, a fluid flow is forced into the fluid line in such a way that the liquid located within the compensation tank is sucked out through the fluid line. Alternatively, the fluid pump is arranged upstream of the protruding helical or spiral-shaped fluid line section along a fluid line section extending outside the reaction vessel.

[0016] Optionally, a filter unit, preferably in the form of a bacterial filter, is installed along the drain leading from the reaction vessel to prevent contamination of the heat exchanger in the oxygenator by germs, e.g. in the form of Legionella.

[0017] The outlet of the fluid line is further preferably connected via a detachable fluid-tight coupling to the inlet of a hose line system which is thermally coupled to a heat exchanger integrated within an oxygenator.

[0018] The fluidic outlet of the hose system thermally coupled to the heat exchanger is preferably connected via a detachable, fluid-tight coupling to the supply line of the fluid line, which leads into the expansion tank. Thus, the expansion tank, the fluid line, and the hose system of the heat exchanger form a self-contained fluid circuit along which the fluid circulates, serving as the heat exchanger's heat transfer fluid. This fluid portion serving as the heat transfer fluid originates from the fluid stored within the reservoir, which, after appropriate local perforation or opening of the reservoir, flows into the expansion tank with the aid of the functional means to be explained in more detail below.

[0019] Due to the limited capacity within the expansion tank, which is smaller than the capacity of the storage tank, the majority of the liquid flows via the overflow along the fluid connection into the reaction tank, where the reactant is stored, preferably in the form of granular urea. Alternative reactants are also suitable, which extract thermal energy from the environment with a liquid, preferably water, forming an endothermic chemical reaction.

[0020] The quantity of liquid stored within the reservoir is dimensioned such that the proportion of liquid flowing into the reaction vessel via the overflow and the fluid connection is at least 70%, whereas the remaining portion of the liquid is retained within the expansion tank, which, as explained above, serves as the heat transfer fluid for the heat exchanger fluidically connected to the cooling unit designed according to the invention. The distribution of the quantity of liquid flowing from or out of the expansion tank via the fluid connection into the reaction vessel can be specified, in particular, by the pipe height at which the fluid connection extends into the expansion tank.

[0021] To prevent the filling of the reaction vessel or the drainage of the liquid from the expansion vessel into the reaction vessel through the fluid connection due to an increase in pressure that would otherwise develop within the reaction vessel, the reaction vessel is provided with at least one vent opening in the upper area near the expansion vessel. The vent opening preferably has a hydrophobic filter insert, which can prevent uncontrolled liquid leakage caused by tilting or moving the cooling unit.

[0022] To support and homogenize the chemical, endothermic reaction between the liquid and the granular reactant, an agitator is also arranged within the reaction vessel. This agitator can be driven via a mechanical interface, e.g., in the form of a gear drive, by a drive motor located outside the reaction vessel. To ensure that no liquid components from the reaction vessel can return to the expansion tank, especially since this would contaminate the liquid inside the expansion tank, a check valve is arranged along the fluid connection.

[0023] To ensure the simplest and most error-free handling of the cooling unit designed according to the invention, the storage container is preferably designed in the form of a liquid bag. Also for reasons of mechanical protection, the liquid bag is located within a first housing arranged vertically above a second housing surrounding at least the expansion tank. A third housing enclosing the reaction tank is arranged vertically below the second housing surrounding the expansion tank. Optionally, the second and third housings can be formed integrally. A spacer is additionally arranged between the first and second housings, ensuring a predetermined vertical distance between the storage container contained in the first housing and the functional means, which is preferably firmly attached to or within the expansion tank.

[0024] The functional means is designed in the form of a sharp-edged object and is preferably arranged vertically below the storage container.

[0025] The spacer, which vertically separates the storage container from the equalizing container and prevents direct contact between the storage container and the sharp-edged functional means, is preferably mounted between the first and second housing in such a way that the spacer can be separated laterally from the stack, for example by manual removal. After removal of the spacer, the storage container falls vertically downwards due to its weight and the force of gravity and comes into contact with the sharp-edged functional means, whereby the storage container is mechanically perforated or opened locally, so that the liquid stored in the storage container pours completely into the equalizing container. Simultaneously with the vertical lowering orWhen the storage tank falls and the compensation and reaction tank is filled, the fluid pump and the drive motor are put into operation to activate the agitator inside the reaction tank.

[0026] The first housing surrounding the storage container and the second housing arranged vertically below it are designed with respect to their vertically directly facing sides in such a way that after removal of the spacer, both housings slide into each other mechanically in a clear manner, for example in the manner of a circumferential tongue and groove connection, forming a firm mechanical joint.

[0027] The cooling unit designed for the rapid and efficient provision of high cooling capacity within a very short time, requiring no additional electrical power supply other than the commissioning of the fluid pump and the drive motor. Due to the limited energy consumption, the required electrical energy can be provided by a battery.

[0028] A preferred embodiment of the cooling unit according to the invention provides a modular structure such that the electrical components, such as the fluid pump and drive motor, along with the required control unit and electrical energy source, are housed in a modular, uniform housing. The first housing enclosing the storage container, the spacer, the second housing enclosing the compensation container, and the third housing enclosing the reaction container are each designed as vertically stackable modular units and can be disposed of as disposable items after use. It is preferably advisable to manufacture at least the storage container and the reaction container from a plastic-based lightweight packaging material, e.g., densely compressed polystyrene, which can be recycled.To ensure the reaction vessel's liquid-tightness, the inner wall of the reaction vessel that comes into contact with the liquid is provided with a liquid-tight coating. Furthermore, the coating material must be selected so that it is chemically inert to the resulting liquid-reactant mixture and the resulting chemical products.

[0029] For reasons of sustainability and careful disposal, it is also advantageous to provide a binder within the reaction vessel that triggers a gel-forming process in reaction with the liquid and / or the resulting liquid / reactant mixture. This allows the reaction vessel, after use of the cooling unit, to be disposed of as household waste due to the gelled mass inside the vessel, thus avoiding costly disposal. The chemical reaction with the binder should preferably occur with a time delay relative to the endothermic reaction between the liquid and the reactant, ensuring a complete reaction between the liquid and the reactant.For this purpose, it is advisable to encapsulate the binder with a liquid-soluble material and store it inside the reaction vessel or to administer it into the reaction vessel with a time delay via a dosage mechanism attached to the reaction vessel. In the case of water as the liquid, xanthan gum is the preferred binder.

[0030] The cooling unit can be fluidically connected to a heat exchanger for any application. Heat exchangers in the form of cooling surfaces or cooling mats, as well as cooling vessels or barrels, are conceivable, to name just a few. The cooling unit is suitable as a cooling source for heat exchangers integrated into stationary or portable cooling units. Brief description of the invention

[0031] The invention is described below, without limiting the general inventive concept, using an exemplary embodiment with reference to the drawing. It shows: Fig. 1 schematic representation of a cooling unit designed according to the solution for controlling the temperature of a heat exchanger integrated in an oxygenator in the stage before activation of the cooling function, Fig. 2 schematic representation of the cooling unit after activation of the cooling function and Fig. 3 alternative design of the cooling unit according to the solution. Ways of implementing the invention, industrial applicability

[0032] Figure 1 illustrates in schematic representation a cooling unit K designed according to the solution for providing a cooled heat transfer fluid for operating a heat exchanger W, which is preferably part of an oxygenator O.

[0033] The cooling unit K essentially has four modules M1 to M4, of which at least the modules M1 - M3 can be assembled vertically one above the other according to the modular principle. The module M1 has a storage container 1 for a liquid, preferably in the form of water. Preferably, the storage container 1 consists of a plastic bag or plastic canister filled with water, which is at least partially surrounded by a first housing 2 for protection and for mechanical attachment to the module M2 located below it.

[0034] Arranged vertically below the first module M1 is the second module M2, which comprises an equalizing tank 3 in which a functional agent 4 in the form of an object tapering vertically upwards with sharp edges, e.g., a needle, mandrel, etc., is fixedly arranged. The equalizing tank 3 is surrounded by a second housing 5. An overflow 6 with a fluid connection 7 projects vertically from below into the interior of the equalizing tank 3. The fluid connection 7 opens vertically from above into the reaction tank 8 of the third module M3, which is surrounded by a third housing 9. The fluid connection 7 is designed as a pipe open on both sides and has a check valve 10 that prevents liquid from entering the equalizing tank 3 from the reaction tank 8. A reactant 11 in granular form, which preferably consists of granular urea, is stored in the reaction tank 8.

[0035] Furthermore, a fluid line 12 opens into the bottom region of the compensation tank 3 and continues within the reaction tank 11, preferably forming line coils 13 in order to achieve the largest possible fluid line surface within the reaction tank 8. The fluid line 12 leads fluid-tight through the third housing 9 to the outside and further serves as a discharge line 14 of the cooling unit K. The fluid line 12 running inside the reaction tank 9 and in particular the line coils 13 located there are made of a material with very good heat conduction, preferably metal, whereas the fluid line along the discharge line 14 is made of a material with poor thermal conduction and is elastic, e.g. plastic.

[0036] A filter unit 15, preferably in the form of a bacterial filter, is installed along the discharge line 14. Downstream of the filter unit 15, a fluid pump 16, preferably in the form of a roller pump, is arranged along the discharge line 14. Downstream of the fluid pump 16 is a detachable fluid-tight coupling 17 for a fluid-tight connection to a hose system 18 associated with the heat exchanger W.

[0037] In the same way, the hose system 18 is connected by a detachable fluid-tight coupling 17' to the fluid line serving as a supply line 19 into the expansion tank 3 of the cooling unit K.

[0038] The third module M3 also has a stirring tool 20, which is coupled to a drive motor 22 via a detachable gear unit 21. The drive motor 22, the fluid pump 16, and an electronic control unit 23 in combination with an electrical energy source 24, which serve to operate the drive motor 22 and the fluid pump 15, form the fourth module M4, which is surrounded by a fourth housing (not shown).

[0039] The first and second modules M1, M2 are vertically spaced apart by a spacer 25, so that the functional means 4, in the form of a vertically upwardly tapered object, does not touch the storage container 1 contained within the first module M1. The spacer 25 is slidably mounted between the first and second modules M1, M2 and is preferably secured against uncontrolled lateral slipping out by means of a locking mechanism (not shown).

[0040] To activate the cooling unit K, the spacer 25 must be removed laterally from the vertical module assembly M1, M2, for example by manually pulling it out sideways, see arrow P.

[0041] Figure 2 illustrates the state after the spacer 25 has been removed from the side of the modular stack. As a result of the missing spacer 25, the storage container 1, including the first housing 2, falls vertically downward, causing the upwardly tapered functional element 4 to locally perforate the storage container 1. To ensure that the dropping and joining process of the first module M1 onto and into the second module M2 takes place in a specific manner, the first and second housings 2, 5 have laterally circumferential joining contours F on their respective vertically facing sides.

[0042] As a result of the mechanically initiated perforation of the storage tank 1, the entire liquid content of the storage tank 1 flows into the equalizing tank 3. Approximately 80% of the liquid quantity stored in the storage tank 1 flows via the overflow 6 and the fluid connection 7 into the reaction tank 8 and initiates an endothermic chemical reaction with the reactant 11, whereby cooling occurs within the reaction tank 8. A residual portion 26 of the liquid remains within the equalizing tank 3 and serves as a heat transfer fluid for operating the heat exchanger W. Simultaneously with the removal of the spacer 25 and the resulting gravity-driven perforation of the storage tank 1, both the fluid pump 16 and the drive motor 22, which drives the stirring tool 20 via the gear unit 21, are activated by means of the electronic control unit 23.The fluid pump 16, operating as a suction pump, draws the residual liquid 26 within the equalizing tank 3 through the fluid line 12, which is cooled due to the cooling within the reaction zone 8. In order to optimize the heat transfer from the liquid conveyed within the fluid line 12 to the liquid / reactant mixture cooling as a result of the endothermic reaction, it is important to ensure the largest possible heat transfer contact area between the fluid line 12 and the liquid / reactant mixture present inside the reaction tank 8. To this end, the path of the fluid line 12 inside the reaction tank 8 is designed to be helical or spiral, at least in sections.

[0043] The cooled liquid is pumped via the outlet line 14 through the filter unit 15 into the heat exchanger W. The heat transfer fluid flowing out of the heat exchanger W returns via the supply line 19 to the equalizing tank 3, from which liquid is again sucked via the fluid line 12 into the area of ​​the reaction tank 8 for the purpose of cooling it.

[0044] Advantageously, the first, second, and third modules M1, M2, and M3 are disposable, whereas the fourth module M4, which comprises the electrical components, can be reused as often as desired. The filter unit 15 is preferably an integral component of the third module M3 and is thus also a disposable component. For weight and cost reasons, the modules M1, M2, and M3 are made of plastic-based lightweight packaging material, which can also be recycled. In addition, the expansion tank 3 and the reaction tank 8, i.e., modules 2 and 3, are provided with a liquid-tight internal coating.

[0045] In Figure 3 is a further preferred embodiment for the design of the cooling unit in the state of the directly vertically mounted modules M1, M2 and M3, comparable to the representation in Figure 2, illustrated. All components that are identical to those already explained are provided with the reference symbols already introduced.

[0046] In contrast to the representation in Figure 2 The fluid line 12 leads directly downstream to its fluidic connection to the equalizing tank 3 to the outside, i.e. outside the reaction tank 8, where the fluid pump 16 is inserted along the fluid line 12 and sucks liquid from the equalizing tank 3 into the fluid line 12. Downstream of the fluid pump 16 arranged outside the reaction tank 8, the fluid line 12 leads back into the reaction tank 8, within which the fluid line 12 is helically shaped in order to form the largest possible heat transfer contact surface and to ensure effective cooling of the liquid guided within the fluid line 12.

[0047] The filter unit 15 is arranged along the discharge line 14 leading to the outside of the reaction vessel 8 and acts as a bacterial filter, e.g. in the form of a legionella filter, to ensure that the cooled liquid is free of germs in order to prevent contaminating the heat exchanger W inside the oxygenator.

[0048] In addition, the reaction vessel 8 is provided with a venting unit 27 with a hydrophobic filter in the upper area, which ensures complete and rapid filling of the reaction vessel 8 and prevents uncontrolled escape of liquid to the outside.

[0049] After the cooling process is complete, a binder 28, preferably xanthan gum, stored in the reaction vessel 8 ensures gelation of the liquid-reactant mixture, allowing easy disposal of modules 1, 2, and 3, for example, as household waste. For this purpose, the binder 27 is encapsulated with a liquid-soluble material that completely dissolves after a certain residence time within the liquid, releasing the binder within the reaction vessel. List of reference symbols

[0050] 1Storage tank 2First housing 3Compensation tank 4Functional medium 5Second housing 6Overflow 7Fluid connection 8Reaction tank 9Third housing 10Check valve 11Reactant 12Fluid line 13Cable coil 14Drain 15Filter unit 16Fluid pump 17, 17'Releasable fluid-tight coupling 18Hose system 19Supply line 20Stirring tool 21Gear unit 22Drive motor 23Electrical control unit 24Electrical energy source, battery 25Spacer 26Residual liquid 27Venting unit 28Binder WHeat exchanger OOxygenator M1, M2, M3, M4Modules PPFile direction KCooling unit FJoining contour

Claims

1. A cooling unit for a heat exchanger (W), integrated in an oxygenator (O), for the purpose of controlling the temperature of blood conveyed in an extracorporeal blood circuit, comprising: - a reservoir (1) in which a liquid is stored, - a reaction vessel (8) comprising a reactant (11) which, in conjunction with the liquid, can initiate an endothermal reaction, - functional means (4) for providing a fluidic access between the reservoir (1) and the reaction vessel (8), and - a fluid line (12) extending at least in regions inside the reaction vessel (8) and which has an inlet line and an outlet line (14, 19), which are each fluid-tightly connectable or connected to a hose system (18) of the heat exchanger (W), and which, together with the hose system (18) of the heat exchanger (W), forms at least part of a fluid circuit; characterised in that an expansion tank (3) having an overflow (6) into which the liquid from the reservoir (1) flows after fluidic access is generated between the reservoir (1) and the reaction vessel (8), in that the overflow (6) provides a fluid connection (7) to the reaction vessel (8) through which a proportion of the stored liquid passes into the reaction vessel (8) to initiate an endothermal reaction with the reactant (11), in that the fluid line (12) is fluidically connected to the expansion tank (3), into which a remaining proportion (26) of the stored liquid from the reservoir (1) passes, and in that a fluid pump (16) is located along the fluid line (12), by means of which liquid from the expansion tank (3) passes into the fluid line (12) which extends at least in regions inside the reaction vessel (8).

2. The cooling unit according to claim 1, characterised in that a non-return valve (10) is located along the fluid connection (7) of the overflow (6) and prevents a return flow of liquid from the reaction vessel (8) into the expansion tank (3).

3. The cooling unit according to claim 1 or 2, characterised in that the fluid pump (16) is provided in the form of a suction unit located along the fluid line (12) outside the expansion tank and reaction vessel (3, 8).

4. The cooling unit according to claim 1 or 2, characterised in that the fluid pump (16) is formed as a roller pump.

5. The cooling unit according to any one of claims 1 to 4, characterised in that the fluid line (12) downstream of the region extending inside the reaction vessel (8) provides the outlet line (14), and in that a filter unit (15) is located along the outlet line (14) extending outside the reaction vessel.

6. The cooling unit according to claim 5, characterised in that the filter unit (15) is a bacteria filter.

7. The cooling unit according to any one of claims 1 to 6, characterised in that the inlet line (19) of the fluid line (12) feeds into the expansion tank (3), and in that the fluid circuit consists of the expansion tank (3), the fluid line (12) and the hose system of the heat exchanger (W), through which the remaining proportion (26) of the liquid circulates as heat transfer liquid of the heat exchanger (W).

8. The cooling unit according to any one of claims 1 to 7, characterised in that the reservoir (1) is disposed vertically above the expansion tank (3), and in that the functional means (4) is provided in the form of a sharp-edged object positioned vertically below the reservoir (1), in that a spacer (25) is located between the reservoir (1) and the expansion tank (3) and vertically spaces apart the reservoir (1) above the functional means (4), and in that, upon removal of the spacer (25), the reservoir (1) is driven by gravitational force to contact the functional means (4), which consequently mechanically penetrates the reservoir (1) locally, so that the liquid stored in the reservoir (1) pours fully into the expansion tank (3).

9. The cooling unit according to any one of claims 1 to 8, characterised in that the functional means (4) is fixedly positioned on the expansion tank (3).

10. The cooling unit according to any one of claims 1 to 9, characterised in that an agitator (20) is located inside the reaction vessel (8) and is driven via a mechanical interface by a drive motor (22) located outside the reaction vessel (8).

11. The cooling unit according to any one of claims 1 to 10, characterised in that at least the reservoir (1), the functional means (4) and the reaction vessel (8) are disposable articles.

12. The cooling unit according to claims 5, 10 and 11, characterised in that the filter unit (15) and the agitator (20) are parts of the disposable article and the drive motor (22) and the fluid pump (16) are connected to an electrical energy source (24) and an electrical controller (23) and are formed as a modular unit for a mechanical adaptation to the disposable article.

13. The cooling unit according to any one of claims 1 to 12, characterised in that the heat exchanger (W) is integrated in a stationary or portable cooling system.

14. The cooling unit according to any one of claims 1 to 13, characterised in that a binding agent is stored inside the reaction vessel (8) and, upon coming into contact with the liquid entering into the reaction vessel (8), can form a gel with the liquid.

15. The cooling unit according to any one of claims 1 to 14, characterised in that at least the reservoir (1) and the reaction vessel (8) are made of a plastics-based lightweight packaging material.

16. The cooling unit according to claim 15, characterised in that at least the inner wall of the reaction vessel which comes into contact with the liquid is provided with a liquid-tight coating.

17. The cooling unit according to any one of claims 1 to 16, characterised in that the reaction vessel (8) provides a venting unit.