Abstract:
The invention relates to an energy system, and more particularly to an air conditioning system for air conditioning rooms, comprising an energy source for heat pump systems, in which energy and/or heat is stored in a latent energy or heat storage system, comprising an ice slurry production device ( 100 ) for producing ice slurry from a liquid ice slurry brine ( 10 ), which operate according to a method for air conditioning rooms, in which energy or heat is stored or buffered in a latent energy or heat storage system and/or removed or extracted therefrom, wherein ice slurry is provided as the latent energy or heat storage system, or according to a method for producing ice slurry from an ice slurry brine ( 10 ), comprising the following steps: filling a housing ( 110 ) with the liquid ice slurry brine; cooling the liquid ice slurry brine by bringing it in contact with a heat exchanger device ( 220 ) disposed in the housing ( 110 ) while stirring the ice slurry brine ( 10 ) so as to generate the ice slurry, wherein, when an ice layer forms on the heat exchanger device ( 200 ), cooling is interrupted as soon as the ice layer reaches a predetermined thickness, and cooling is continued as soon as the ice layer drops below the predetermined thickness.

Description:
TECHNICAL FIELD OF THE INVENTION 
     The invention relates to a method for producing ice slurry from an ice slurry brine. 
     The invention further relates to a method for air conditioning rooms, in which heat is stored in a latent heat storage system. 
     The invention also relates to an ice slurry production device for producing ice slurry from a liquid ice slurry brine according to the preamble of claim  10 . 
     The invention furthermore relates to an air conditioning system for air conditioning rooms or for heating process water, as an energy source for heat pump systems, in which energy and/or heat is stored in a latent heat storage system and/or withdrawn therefrom. 
     And finally the invention relates to a use of ice slurry. 
     Ice slurry, methods and devices for the production thereof are generally known. Ice slurry is also referred to as ice slush, slurry, slush ice, slurry ice, pumpable ice, liquid ice and the like. 
     DISCUSSION OF RELATED ART 
     An ice making machine is known from DE 34 86 374 T2, comprising: a housing having an inlet for receiving a liquid in the form of an aqueous solution having a concentration that is below the eutectic concentration thereof, from which the ice is to be made; an outlet to allow ice to egress from the housing; a heat exchanger in the housing, having a coolant inlet and a coolant outlet to allow a flow of coolants for the purpose of extracting heat from the liquid, and at least one heat exchanger surface, which separates the coolant from the liquid; a scraper, which is disposed in the housing and is movable about an axis, wherein the same is disposed in the housing and is movable about an axis, wherein the scraper and the aforementioned respective heat exchanger surface extend transversely to the aforementioned axis; means for receiving an amount of liquid in the housing so as to substantially fill the housing and cover the respective heat exchanger surface, wherein the scraper is in contact with the respective heat exchanger surface and can be moved about the axis so as to scour the respective heat exchanger surface, and the ice making machine further comprising: a drive, which drives the scraper and moves the same across the aforementioned heat exchanger surface at such a speed that the scraper scours the respective heat exchanger surface during consecutive revolutions over the same so as to scrape off a cooled layer of the liquid from the respective heat exchanger surface before the ice crystallizes thereon, wherein the scraper supplies liquid from the respective heat exchanger surface to the total liquid in the housing so as to maintain a substantially uniform temperature there. 
     Therefore, it is an object of the present invention to create a method and an ice slurry production device in which ice slurry is generated more homogeneously and efficiently. Moreover, it is an object to use the ice slurry, or the method and the device for the production thereof, for an air conditioning or energy system using ice slurry as a latent energy storage system. 
     These and further objects are achieved proceeding from a method, an ice slurry production device, an air conditioning system, and a use in conjunction with the features thereof as described herein. Advantageous refinements of the invention are described in the dependent claims. 
     SUMMARY OF THE INVENTION 
     The invention encompasses the technical teaching that, in a method for producing ice slurry from an ice slurry brine, comprising the steps of: filling a housing with the liquid ice slurry brine; cooling the liquid ice slurry brine, or the ice slurry that has already been produced, by bringing it in contact with a heat exchanger device, or, in more general terms, with a cooling device, disposed in the housing while stirring, in particular continuously stirring, the ice slurry brine so as to generate the ice slurry, it is provided that, when an ice layer forms on the heat exchanger device, cooling is interrupted as soon as the ice layer reaches a predetermined thickness, and that cooling is continued as soon as the ice layer drops below the predetermined thickness. The ice slurry is produced from a liquid ice slurry brine. For this purpose, an ice slurry brine having a predetermined percentage of salt is produced. The ice slurry brine preferably comprises water, for example tap water, and a salt, for example common salt, NaCl or the like, as constituents. The ice slurry brine is preferably mixed as an approximately 0.01 to 10% ice slurry brine, preferably as an approximately 0.5 to 4.5% ice slurry brine, and most preferably as an approximately 1.0 to 3.5% ice slurry brine. So as to provide a desired ice slurry brine having an appropriate mixing ratio, a saturated salt solution of the ice slurry solution is provided. For example, when using NaCl and H 2 O as the ice slurry brine, a saturated solution of NaCl+H 2 O is provided or mixed in one step. Moreover, separately from this, a further ice slurry brine is provided. In the further ice slurry brine, first a desired solution ratio of NaCl to H 2 O is detected. If the sodium chloride (NaCl) content, or the salt content in general, of the solution is too high, H 2 O is added. If the H 2 O content of the solution is too high, some of the saturated ice slurry brine is added to the further ice slurry brine. This level regulation is preferably regulated automatically or via a regulating loop. In this process, a desired concentration value is established. The concentration value is ascertained. If desired concentration value is exceeded or no longer met, a desired constituent is added, for example from the saturated solution or an unsaturated solution and/or a solution having a low concentration. When a desired concentration value is reached, the ice slurry brine is added to a container in which the cooling takes place. The container preferably has a cylindrical design; in another mode it has a conical design. The container is preferably insulated in keeping with the temperature of the medium and the ambient temperature so as to prevent transmission heat losses and dropping below the dew point. In another embodiment, the container has a double-walled design so as to create an additional heat exchanger surface on the inside wall. The container is preferably designed as a cooling container; in another embodiment, it is designed as a heating container, or as a cooling and heating container. In one step, the ice slurry brine is pre-cooled before being added to the container. Adding is preferably carried out in a controlled manner, in particular controlled as a function of a fill level of the container. The adding is preferably controlled in such a way that a desired fill level is adhered to. As soon as the ice slurry brine having the desired concentration ratio is added to the container, and the brine thus makes contact with the heat exchanger located there at the appropriate heat exchanger surfaces, the process of cooling the ice slurry brine commences. Cooling takes place in a controlled manner, for example in a temperature-controlled, time-controlled, energy-controlled, ice thickness-controlled manner, or the like. Cooling preferably takes place while continuously stirring the ice slurry brine. In this way, thorough mixing of the ice slurry brine is achieved from the outset. Over the course of the process of cooling the ice slurry brine, crystals form, and thus an ice layer forms at the heat exchanger surfaces. Since stirring takes place without contact with the heat exchanger surfaces, stirring is initially not blocked by the ice layer. However, stirring also takes place in close proximity to the heat exchanger surfaces. Here, a distance between a stirring surface of a stirring element and a heat exchanger surface is selected in such a way that stirring cannot be blocked until a predetermined ice thickness has been reached. The distance is thus selected so that it is in the range of approximately 0.1 to 60 millimeters, preferably in the range of approximately 0.1 to 30 millimeters, and most preferably in a range from 0.1 to 5 millimeters. If an ice layer is formed on the heat exchanger surface which has an ice layer thickness that exceeds a predefined value, cooling is interrupted, so that the ice that has formed on the heat exchanger surface can thaw or can dissolve in the ice slurry brine. As soon as the ice layer thickness drops below a predefined value, or as soon as a predefined time window or another controlled variable is exceeded, cooling is continued. This process continues until a desired consistency of ice slurry has been reached. The finished ice slurry is pumpable and is withdrawn from the container via a draw-off point. 
     The ice slurry production device is designed to produce from approximately 5 kg to 20 t of ice slurry per hour, and preferably from 25 kg to 250 kg. 
     In one embodiment, a food-safe cooling medium, for example food-safe brine or the like, is used as the cooling medium for cooling by way of the heat exchanger. In this way, the method and the device described hereafter for producing ice slurry can be used in the food industry. In the event of a potential leakage, the food-safe cooling medium comes in contact with the ice slurry, and consequently there is no risk for users from contamination. A refrigerant for cooling the cooling medium flows through a secondary circuit. In other applications, for example when cooling concrete or the like, a technical brine is used instead of a food-safe cooling medium. In general, a water/antifreeze mixture is used as the cooling medium. 
     In another embodiment, a refrigerant is used as the cooling medium for cooling, so that the method or the device is operated in a direct evaporator mode or as a direct evaporator. A refrigerant is CO 2  or the like, for example. 
     One embodiment of the present invention provides for a layer thickness detection to be carried out. The layer thickness detection is carried out in a variety of ways, for example directly, by directly measuring the layer thickness, for example visually, haptically, by way of acoustic or other waves, or the like, or indirectly, for example by detecting derived variables. The layer thickness detection is preferably carried out indirectly. The layer thickness detection is carried out, for example, by way of stirring or by a distance between the ice and a stirring element. If the ice layer is too thick, stirring is blocked. As a result, the resistance increases for a stirrer carrying out the stirring. By detecting the resistance, it is possible to infer when an ice layer is too thick. Cooling is accordingly interrupted when the increase in resistance is sufficient. The interruption takes place in a time-controlled manner, an ice layer thickness-controlled manner, a temperature-controlled manner, or the like. For example, the interruption takes place for a preset or variable time period. In another embodiment, the interruption takes place as a function of the ice layer thickness, and in other embodiments as a function of the resistance. In another embodiment, the layer thickness detection is carried out in a manner integrated with the stirring process. 
     In another embodiment of the present invention, it is provided that stirring takes place without contact with the heat exchanger device. Stirring takes place without contact with the heat exchanger device, and more particularly the heat exchanger surfaces. Stirring takes place along the heat exchanger surfaces, whereby thorough mixing of the ice formed on the heat exchanger surfaces and the ice slurry brine is achieved. Parallel stirring in multiple locations is preferred. The stirring process is in particular designed as an axial and/or radial stirring process. In one embodiment, stirring takes place in a plane, for example in a plane parallel to the heat exchanger surfaces. The ice slurry brine and/or the ice is preferably moved radially outwardly along the heat exchanger surfaces. In another embodiment, stirring takes place in at least one further direction, for example perpendicularly to the above-described direction. 
     Yet another embodiment of the present invention provides for the method to be carried out in a slanted position. In particular, at least the housing is inclined for carrying out the method. For this purpose, the housing, the heat exchanger device and/or the stirring device or the stirrer are oriented obliquely. Due to the different properties of the ice slurry, the ice and the ice slurry brine, the ice slurry brine is moved to the lowermost point of the housing in the case of a slanted position, for example due to gravity. Due to the lower density, the finished ice slurry is moved to a higher point. Finished ice slurry is thus situated in a higher position. Accordingly, ice slurry that is not yet finished, for example ice slurry brine, or ice slurry brine with non-mixed ice, will be situated at a lower point or location. By appropriately disposing a draw-off point in a higher location, ice slurry can thus be withdrawn from the container before the entire ice slurry brine has been converted into ice slurry. In this way, an improved production of ice slurry can be achieved, since ice slurry can be withdrawn sooner, and thus ice slurry brine can be added sooner based on the level regulation or fill level control. The slanted position is controlled by way of a regulating unit, for example. In one embodiment, for example, an angular range of approximately 0° to approximately 90°, preferably from approximately 5° to approximately 35°, and most preferably an angular range of approximately 10° to approximately 20°, and preferably around 15° is set. Other values can likewise be set. In one embodiment, the slanted position is varied during the production of the ice slurry. For example, the slanted position is greater at the beginning of a production process and decreases over the course of the process. Cooling can be adjusted in keeping with the presently set slanted position. For example, stronger cooling takes place with a more heavily slanted position, for example cooling takes place to an increased extent in the region of the lower-lying heat exchanger surfaces. In one embodiment, the fill level is set in keeping with the slanted position. For example, the fill level is lower with a more heavily slanted position. In one embodiment, originally higher-lying heat exchanger surfaces are activated and/or deactivated as the slanted position decreases. 
     Yet another embodiment of the present invention provides for the ice slurry and/or the ice slurry brine to be conveyed in at least one direction, and preferably in multiple directions. A preferred direction is from the inlet to the outlet of the ice slurry or the ice slurry brine. As a result of the slanted position, conveying is supported by gravity, for example. In other embodiments, stirring devices or stirrers are provided, which convey by way of a helical movement, for example, such as by way of a spiral conveyor. Stirring preferably takes place along a plane of the appropriate heat exchanger surface. As a result of the slanted position or inclination and the different properties of the ice slurry and of the ice slurry brine, mixing takes place transversely to the plane along which stirring is carried out. 
     One embodiment of the present invention moreover provides for cooling to be carried out in parallel and/or in series on more than two surfaces of the heat exchanger device. Multiple surfaces are provided for cooling purposes. As a result of a slanted position or slanting, in particular also varying slanting, cooling does not constantly take place on the same fraction of all heat exchanger surfaces. Some of the cooling takes place in parallel. When the slanted position is changed, cooling takes place consecutively on a variable fraction of the heat exchanger surfaces. 
     Individual heat exchanger surfaces can preferably be activated and/or deactivated. 
     In addition, one embodiment of the present invention provides for level regulation. The level regulation includes regulation of a fill level of the container, regulation of a concentration of the ice slurry brine, and regulation of a slanted position. The level regulation is carried out in particular as a function of different variables such as concentration variables, temperature variables, time variables, angle variables, fill level variables and the like. Dependencies of the individual variables are preferably detected. The regulation is preferably designed as a self-learning regulation. In one embodiment, automatic optimization is carried out based on the detected values, the actual values and the setpoint values, in particular as a function of target specifications. 
     Still another embodiment provides for cooling to be carried out by way of indirect heat exchanger operation. For this purpose, a primary circuit and a secondary circuit are provided. For example, a food-safe brine is circulated in the primary cooling circuit. A refrigerant is circulated in the secondary circuit, for example. In another embodiment, direct heat exchanger operation having one circuit is provided. A refrigerant is circulated in the circuit, for example. 
     The invention encompasses the technical teaching that, in a method for air conditioning rooms, in which energy and/or heat is stored or buffered in a latent energy or heat storage system, or is withdrawn or extracted therefrom, it is provided for that ice slurry, and more particularly ice slurry produced according to a method according to the invention, is provided as the latent energy or heat storage system. For example, the energy that is stored in the ice slurry can be used not only for cooling, but also for heating rooms or the like, when using appropriately designed heat pumps and heating circuits. For this purpose, the ice slurry is appropriately stored and optionally added using appropriate control. Heating and/or cooling can be achieved when using ice slurry as an energy store. Switching between these is possible. 
     The invention moreover encompasses the technical teaching that, in an ice slurry production device for producing ice slurry from a liquid ice slurry brine, it is provided for that means for carrying out the method according to the invention are present. The means allow improved ice slurry production, and more particularly allow ice slurry production that is faster, more energy-efficient and optimized for large-scale production. Effective ice slurry production is achieved in particular by the flexible design, including changing the inclination or slanted position. The means in particular ensure continuous ice slurry production. 
     One embodiment of the present invention provides for the means to comprise a heat exchanger device, which includes multiple heat exchanger plates that are disposed at a distance from each other, at least some of which being fluidically connected to each other. The heat exchanger device comprises a heating or cooling agent circuit in which a heating or cooling agent can circulate or flow. The circuit comprises a feed and a drain. The heat exchanger plates are fluidically connected to the feed and the drain. The coolant flows through the interior space of the heat exchanger plate. A flow field is formed in the respective interior space, the flow field accordingly defining a flow of the coolant. For this purpose, corresponding flow guide means are provided in the interior space. These include protrusions, depressions, constrictions, widened regions, walls and the like. The interior space is delimited by appropriate walls. The lateral walls form the largest fraction of the walls in terms of expanse. The heat exchanger plates are preferably designed as plates having a circular cross-section, or as circular ring-shaped plates, having two side walls and one or two circumferential walls. The respective side wall has an outer side, this being the heat exchanger surface, and an inner side. The flow guide means extend from an inner side to the opposite inner side in one embodiment. In another embodiment, the flow guide means do not extend from an inner side to the opposite inner side, but project from one side in the direction of the other side, or transversely thereto, without making contact with the respective other side. The flow guide means have identical and/or different orientations. For example, an arbitrary flow field is formed in the interior space for optimized flow. 
     The heat exchanger plates preferably have a central through-passage, through which an axle or a shaft can extend, for example. The heat exchanger plates are preferably oriented concentrically with respect to each other. In one embodiment, the heat exchanger plates are connected to the feed or to the drain which is located outside the heat exchanger plates, so that the feed or the drain is disposed radially outside the heat exchanger plates. In another embodiment, a receptacle for at least a portion of the feed and/or of the drain is provided, which is integrated at least partially into the heat exchanger plates. For example, a respective through-passage for the feed and/or the drain is provided in the respective heat exchanger plate. The respective heat exchanger plate accordingly is connected to the feed or drain which is located inside the heat exchanger plate. Preferably multiple heat exchanger plates are oriented parallel to each other along an at least imaginary axis extending through the heat exchanger plates. The heat exchanger plates are preferably designed rotationally symmetrical with respect to the axis. Eccentric forms are provided in other embodiments. In one embodiment, the heat exchanger plates are disposed at a fixed distance from each other. The heat exchanger plates are preferably designed to have the same distance from each other. In other embodiments, the heat exchanger plates are spaced differently from each other, for example at different distances. In another embodiment, the heat exchanger plates are disposed at variable distances from each other. For example, the heat exchanger plates can thus be disposed more closely together or further apart from each other. In this way advantages can be achieved, in particular for transport or for a changed slanted position during operation. In one embodiment, a locking mechanism for locking the respective heat exchanger plate in a position is provided. 
     According to another embodiment of the present invention, the means include a regulating device for down-regulating the heat exchanger device when an ice slurry layer thickness is exceeded and up-regulating the heat exchanger device in the event of a drop below the ice slurry layer thickness. Down-regulating or up-regulating refers to changing the power of the heat exchanger device, for example so as to lower (down-regulate) or raise (up-regulate) a cooling power. The regulating device includes an ice layer thickness detection function. 
     According to another embodiment of the present invention, a stirring device, which is disposed at a distance from the heat exchanger device, is provided for stirring the ice slurry brine and/or the ice slurry, without making contact with the heat exchanger device. The stirring device is designed so as not to make contact with the heat exchanger device, and more particularly with the heat exchanger plates. The stirring device preferably comprises a drive unit, and preferably a drive shaft. The drive shaft is preferably disposed through the central through-passages of the heat exchanger plates. To this end, the drive shaft is disposed at a distance from the heat exchanger plates. Stirring elements, which are disposed at a distance from the respective heat exchanger plates, project radially from the drive shaft. The stirring elements are designed as stirring rakes, for example. In another embodiment, the stirring elements are designed as stirring paddles. In still another embodiment, the stirring elements are designed as stirring rods. Yet another embodiment provides for the stirring elements to be designed as stirring brushes, and another embodiment is a combination of these. Further embodiments of the stirring elements are conceivable. The stirring elements are rotated by the drive shaft in the intermediate space between two neighboring heat exchanger plates. As a result, they push the ice slurry or ice slurry brine radially outward. Since the drive shaft is disposed at a distance from the respective heat exchanger plate, ice slurry brine or ice slurry can move up. For stirring to the outside, the stirring elements comprise appropriate conveying or guide means. The stirring device or the stirrer is coupled to the regulating unit and/or to the stirring device, or is at least partially integrated therein. The regulating unit is responsible for the switching of stirring intervals, stirring speed and the like. The controlled variable that is used can be the brine and/or ice slurry consistency, the power consumption, such as that of the stirrer motor, the temperature of the container wall and/or of the container contents or the like. 
     Moreover, in one embodiment of the present invention, it is provided that the means include an inclination regulating unit for inclining the ice slurry production device. The inclination regulating unit is preferably disposed on the outside of the container in which the heat exchanger device and the stirring device are disposed. The inclination regulating unit preferably comprises one or more extendable and/or pivotable pedestals, mountings or the like. In one embodiment, a weighing device is provided, on which the container is disposed. Weighing feet or weighing sensors are accordingly provided, in the place of simple pedestals. In this way, it is possible to detect the weight and/or regulate or control the weight when drawing off or supplying ice slurry or ice slurry brine. In particular a metering device can thus be implemented by way of weight control. In one embodiment, a level detection unit is provided for, which detects an angle of inclination. In another embodiment a drive is provided, for example a hydraulic, pneumatic or other drive. 
     Moreover, according to one embodiment of the present invention, the means include a conveying device, preferably integrated into the stirrer, for conveying the ice slurry or the ice slurry brine. Conveying preferably occurs from an inlet to an outlet. For example, the inlet and the outlet are not located at the same height. The outlet is preferably located at a higher level, so that conveying occurs in the direction of the outlet with an appropriate inclination. 
     The invention further encompasses the technical teaching that it is provided that an energy system, in particular an air conditioning system for air conditioning rooms and/or for heating process water or the like, as an energy source for heat pump systems, in which energy and/or heat is stored in a latent energy or heat storage system and/or extracted or discharged therefrom, includes an ice slurry production device according to the invention for carrying out a method according to the invention, so as to provide ice slurry, and more particularly ice slurry produced using the ice slurry production device according to the invention, as the latent energy or heat storage system. 
     Finally, the invention encompasses the technical teaching that a use of ice slurry, and more particularly of ice slurry produced according to a method according to the invention and/or produced using an ice slurry production device according to the invention, as a latent energy or heat storage system is provided, in particular for cooling foodstuffs such as in fresh fish refrigeration, dough refrigeration, in energy or heat storage such as the storage of latent energy or heat in energy or thermal systems, energy or heat recovery systems and the like. 
     In one embodiment, the device is used for the operation with a heat pump. In this process, the ice slurry is produced as a waste product, for example. By using ice slurry in such a system, a high energy performance latent heat storage system is implemented. 
     When using a device, heat from solar radiation and/or heat from the ambient air is used. A portion of the heat is buffered in the ice water storage tank, where the heat is stored substantially loss-free. The extremely high heat transfer in the water/ice storage tank allows this to have a capacity of 300 to 400 liters, for example. During the summer, the heat pump requires no energy, or only very little energy. When it is used as a heating device, the heating device preferably comprises at least one hybrid collector, a heat pump, a liquid ice storage tank, and a heat storage system. In particular space-saving energy storage systems are provided as the liquid ice storage tank or water/ice storage tank. In conjunction with a heat pump, energy can be used at a usable temperature level, for example for heating a room and/or for heating hot water. The closer the required usage temperature is to the melting point of water, the higher the efficiency, and the lower the current for the heat pump in order to achieve the desired temperature. The components of a corresponding heating device—the ice storage tank, the collector and the heat pump—are designed for the respective heat requirements. An adsorber is running continuously, which is to say during the day and also at night. Special hybrid collectors still absorb sufficient heat even with diffuse light levels and under cloudy conditions, so as to convert the same into usable heat thereafter or store the excess supply in the (liquid) ice storage tank. During summer days, hot water supply can be handled directly by collectors, without the heat pump, by conducting the heat into the buffer storage unit. During the winter, the energy is conducted into the heater or the buffer storage unit, if the temperatures of the collectors are sufficient. If the temperatures are not sufficient, the heat is brought to the usable temperature by the heat pump or stored in the ice storage tank on an intermediate basis. The hot water storage tank keeps the heat energy that is required for generating hot water available. In this way, heating using ice or liquid ice is possible in a simple manner. Heating using ice is based on the following physical principle: the so-called heat of crystallization can be extracted as a result of the formation of crystals by way of energy withdrawal during ice formation. During thawing, exactly the same heat must be supplied again. This can be repeated any arbitrary number of times and is a characteristic of water as a medium. The water/ice storage tank or liquid ice storage tank is not used as the actual heat source for this purpose, but always as an intermediate storage unit that is loaded and unloaded any arbitrary number of times. Heat is withdrawn from the liquid ice storage tank as follows: heat is extracted from the water by way of a heat pump until ice forms. With powerful ice storage heat exchangers, the heat pump operates particularly efficiently until the water has completely frozen having a freezing temperature of 0 degrees, since the operating temperature of the heat pump does not drop. It is important for high heat transmission in the high performance ice storage tank that the heat exchanger have a large surface and that there be a small distance of just a few centimeters at the heat exchanger surfaces. The heat extracted by the heat pump can be used at a higher (usable) temperature by the heat pump dissipating his heat to a buffer storage unit for heating, or for heating water. Preferably liquid ice is used, which is made available via the device according to the invention. In this case, the device forms part of the heating device. The heat supply via the ice storage tank takes place as follows: energy or heat can be supplied to the ice storage tanks, for example, by way of an air-to-air heat exchanger comprising a fan, solar collectors, or a combination thereof, known as hybrid collectors. The more efficiently the collectors operate, for example, being even able to cause snow to slide off or thaw, the smaller the ice storage tank can be. 
     In this case, a design intended for one night is sufficient, since even a cloudy sky the next day suffices to harvest sufficient energy again via the collectors. Instead or an ice storage tank, or in addition to this, a liquid ice storage tank is preferably provided. The energy that is extracted from the ice during freezing can be used for heating purposes. This offers two important advantages: ice storage tanks, and more particularly liquid ice storage tanks, are relatively inexpensive and extremely space-saving. The operating principle is as follows: when one liter of ice having a temperature of zero degrees Celsius is converted into water (thawed), the energy that is required is the same as when heating one liter of water having a temperature of zero degrees Celsius to eighty degrees Celsius. In this way, eight times the amount of energy can be stored in the same volume as compared to a water storage tank. Due to the involvement of a heat pump, low-temperature energy can be rendered usable by bringing it to appropriate temperatures for heating and for heating hot water. As a result of the high energy density, a lot of space can be saved. The liquid ice generator differs drastically with regard to the method of producing the ice in terms of the type of ice use, which is to say, solidly frozen water with ice heating, as compared to liquid ice brine with the liquid ice generator. Liquid ice, ice slurry or pumpable ice is preferably used here. When using the liquid ice generator, a closely similar kind of energy extraction (energy recovery) and storage can be practiced. The advantage of liquid ice is that it thaws very quickly even when small amounts of heat are supplied. In this way, the liquid ice generator can be used very well as a renewable heat source for heat pumps, even at very low temperatures just above 0° C. and weak solar radiation. 
     The invention will be described hereafter in greater detail based on exemplary embodiments shown in the drawings. Uniform reference numerals are used for identical or similar components or features. Features or components of different embodiments can be combined so as to obtain further embodiments. All of the features and/or advantages that are apparent from the claims, the description or the drawings, including design details, arrangement in terms of space, and method steps, can thus be essential to the invention, both alone and in a wide variety of combinations. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  schematically shows a cross-sectional view of an ice slurry production device; 
         FIG. 2  schematically shows a section of an ice slurry production device in another cross-sectional view; 
         FIG. 3  schematically shows an exploded illustration of the ice slurry production device of  FIG. 2 ; 
         FIG. 4  schematically shows another cross-sectional view of the ice slurry production device of  FIG. 3 ; 
         FIG. 5  schematically shows a perspective view of a heat exchanger device of an ice slurry production device; 
         FIG. 6  schematically shows a top view onto the heat exchanger device of  FIG. 5 ; 
         FIG. 7  schematically shows a perspective view of another heat exchanger device of an ice slurry production device; 
         FIG. 8  schematically shows a top view onto the heat exchanger device of  FIG. 7 ; 
         FIG. 9  schematically shows a side view of an ice slurry production device; 
         FIG. 10  schematically shows a front view and a side view of a section of the ice slurry production device of  FIG. 9 ; 
         FIG. 11  schematically shows a partially exploded side view of the ice slurry production device of  FIG. 10 ; 
         FIG. 12  schematically shows a cross-sectional view of another ice slurry production device; 
         FIG. 13  schematically shows another cross-sectional view of the ice slurry production device; and 
         FIG. 14  schematically shows a perspective view of a heat exchanger device of the ice slurry production device of  FIG. 13 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1 to 14  show different embodiments of a heat exchanger device  100  in different views and levels of details. Identical or similar components are denoted by identical reference numerals. A detailed description of components that were already described is dispensed with. 
     The ice slurry production device  100  for producing ice slurry from a liquid ice slurry brine comprises means for carrying out a method for producing ice slurry from an ice slurry brine  10 , wherein the liquid ice slurry brine  10  is filled into a housing  110 , the liquid ice slurry brine  10  is cooled by bringing it into contact with a heat exchanger device  200  disposed in the housing  110  while stirring the ice slurry brine  10 , so as to generate the ice slurry, wherein, when an ice layer forms on the heat exchanger device  200 , cooling is interrupted as soon as the ice layer reaches a predetermined thickness and cooling is continued as soon as the ice layer drops below the predetermined thickness. 
     The ice slurry production device  100  comprises corresponding means, which include the heat exchanger device  200 . The means further include a regulating device. The means moreover include a stirring device  500 . The means additionally include an inclination regulating unit  400 . The means further include a conveying device  600 . The ice slurry production device  100  is disposed on a floor or a support base  20 , which can also be designed as a weighing device. The inclination regulating unit  400  can be used to bring the ice slurry production device  100  into a slanted position, or to incline it, with respect to the support base  20 , as is shown in  FIG. 1 . An angle of inclination  410 , at which the ice slurry production device  100  is inclined with respect to the support base  20 , can be set by way of the inclination regulating unit  400 . The angle of inclination  410  here is calculated from a slanted position of the housing  110  of the ice slurry production device  100 , or an axis A of the ice slurry production device  100 , with respect to the support base  20 . The inclination regulating unit  400  comprises at least one adjustable inclination element  420 , which can be extended. The inclination element  420  is designed as an extendable pedestal  421  here. The support base  20  is preferably part of the inclination regulating unit  400 . For the ice slurry production device  100  to rest on a supporting structure, the inclination regulating unit  400  comprises appropriate pedestals  21 , which can also be designed as weighing feet. 
     In addition to the ice slurry brine  10 , the heat exchanger device  200  is also disposed, at least partially, in the container  110 . The heat exchanger device  200  comprises a flow or feed  210  for a heating or refrigerating agent (in short, a refrigerant), a drain or return  220  for the refrigerant, and multiple heat exchanger plates  230  that are fluidically connected to the flow  210  and the return  220 . The refrigerant can flow through the heat exchanger plates  230 . So as to achieve optimal flow, the heat exchanger plates  230  have an interior space, which is surrounded by two end-face side walls and a wall disposed in the manner of a lateral face thereto, and the interior space is fluidically connected both to the flow  210  and to the return  220 . For the formation of an appropriate through-flow, various flow guide means  235  are disposed in the interior space so as to implement a particular flow field, for example. The flow  210  and the return  220  are disposed eccentrically relative to the heat exchanger plates  230 . The flow  210  and the return  220  extend in the axial direction A. The housing  110  further comprises a supply point  111  and a draw-off point  112 . As is indicated by the arrows at  111  and  112 , the supply of ice slurry brine  10  or the removal of ice slurry takes place accordingly. 
     The ice slurry brine  10  is supplied to the container or the housing  110  via the supply point  111 . For this purpose, the ice slurry brine  10  is supplied to the housing  110  via a level regulating unit  700 . The level regulating unit  700  comprises a first brine container  710  and a second brine container  720 . A saturated ice slurry brine  10  is stocked in the first brine container  710 , for example a saturated salt solution. The second brine container  720  holds the ice slurry brine  10  having a desired ice slurry brine concentration, for example a 0.5 to 3.5% salt solution (volume % or mass %). So as to obtain the desired concentration value, the concentration in the second brine container  720  is detected. If the concentration exceeds the desired concentration value, the ice slurry brine  10  is diluted, for example by supplying ice slurry brine  10  having a lower concentration or water. If the concentration is below the desired concentration value, the ice slurry brine  10  is concentrated, for example by supplying ice slurry brine  10  having a higher concentration, preferably using saturated ice slurry brine  10  from the first brine container  710 . If a desired concentration is present, the ice slurry brine  10  from the second brine container  720  is supplied to the container  110 . Supplying takes place in keeping with the level regulating unit  700 . In addition to regulating the concentration of the ice slurry brine  10 , this unit regulates in particular the ice slurry brine  10  in the second brine container  720 , as well as other parameters. For example, the level regulating unit  700  also regulates the fill level of the ice slurry brine  10  in the container  110 . For example, this is done by way of a float gauge measurement, visually or using other means. So as to produce ice slurry from the ice slurry brine  10 , the ice slurry brine  10  is cooled, and more particularly pre-cooled, in the container  110 . For this purpose, the level regulating unit  700  includes a refrigeration controller or a corresponding refrigeration circuit. The ice slurry brine  10  is cooled by bringing it in contact with heat exchanger surfaces of the heat exchanger plates  230 . To produce ice slurry, it is necessary to mix ice slurry brine  10  and crystallized or frozen ice slurry brine  10 . This is done by way of the stirring device  500 . The stirring device  500  comprises a stirring drive  510 . The stirring drive  510  comprises a stirring shaft  520  and a stirring motor  530  driving the stirring shaft  520 . The stirring shaft  520  is disposed centrically relative to the heat exchanger plates  230 . For this purpose, the heat exchanger plates  230  each have a central through-passage  231 , through which the stirring shaft  520  extends. Projecting radially outwardly, the stirring shaft  520  comprises stirring elements  540 , which are designed to mix or stir the ice slurry brine  10 , or the ice slurry, or the mixture of both. The stirring elements  540  are disposed in the intermediate spaces  232  between the heat exchanger plates  230 . The stirring elements  540  have a paddle-like design, so that the ice slurry brine  10  or the ice slurry is moved radially outwardly away from the stirring shaft  520  in the direction of the container wall  110   b . The ice slurry brine mixture that is richer in ice is preferably transported radially outwardly. The ice slurry brine mixture containing less ice, or the ice slurry brine  10 , follows in through the through-passages  231  of the heat exchanger plates  230 . In this way, efficient mixing is achieved. Moreover, improved mixing takes place due to the slanted position of the container  110 , and thus of the heat exchanger device  100  and the stirring device  500 . Mixing is supported by the action of gravity. So as to additionally convey the ice slurry or the ice slurry brine  10 , the appropriate conveying device  600  is provided. This is integrated into the stirring device  500  in the embodiments shown here, in particular by the shape of the stirring elements  540 . The conveying device  600  is also partially integrated into the inclination regulating unit  400  since the slanted position supports conveying of the ice slurry or of the ice slurry brine  10 . Due to the slanted position and the lower density of the ice slurry compared to the ice slurry brine  10 , the ice slurry moves from the lowest point, where the supply point  111  is located, toward a higher location. The draw-off point  112  is formed at the higher location. The slanted position ensures that the ice slurry, or depending on the slanted position an ice slurry mixture having a lower content of ice slurry brine  10 , is present at the draw-off point  112  and can be drawn off there. So as to accelerate the ice slurry production process, drawn-off ice slurry or ice slurry mixture can be recirculated to the supply point  111  and re-supplied to the container  10 . The slanted position can be adjusted for this purpose, for example. 
       FIG. 1  schematically shows a cross-sectional view of the ice slurry production device  100 . Here, the composition is schematically illustrated. The container  110  has three maintenance openings  113 . The set angle of inclination is approximately 10°. The container  110  is filled almost to the rim. Two different fill levels are indicated, which can be set by way of the level regulating unit  700 . The stirring shaft  520  is mounted on an end-face wall or end face  110   a  of the container  110  near the supply point  111 . The stirring motor  530  is provided on the opposite side. It is located outside the container  110 . The stirring shaft  520  penetrates the end wall or end face  110   a  on the draw-off point side of the container  110  and is appropriately sealed. As a result of the slanted position, a pressure exerted by the ice slurry brine  10 , or the ice slurry, on the seal is lower than at the supply-side end face  110   a . The slanted position accordingly improves sealing. 
       FIG. 2  schematically shows a section of the ice slurry production device  100  in another cross-sectional view. The level regulating unit  700  is not shown here. As in  FIG. 1 , the insulated container or the housing  110  is designed as a thin-walled, approximately cylindrical container  110  having two end faces  110   a  that curve slightly to the outside. The container  110  accordingly extends along the axial direction A. The central axis of the container  110  and the central axis of the stirring shaft  520  are formed concentrically with respect to each other. The heat exchanger plates  230  are designed as circular ring-shaped plates and project radially outwardly from an imaginary central axis. The imaginary central axis of the heat exchanger plates  230  is disposed concentrically with respect to the central axis of the stirring shaft  520  and of the container  110 . The heat exchanger plates  230  are disposed at identical distances from each other in the axial direction A. Radially, the heat exchanger plates  230  are disposed at identical distances from the side wall  110   b  of the container  110 . The stirring elements  540  are disposed between the heat exchanger plates  230  so as to project radially outward. The stirring elements  540  are formed at identical distances from each other in the axial direction A and have substantially identical designs. The stirring elements  540  are disposed at a distance from the heat exchanger plates  230  for contactless stirring. The stirring elements  540  are formed at a distance from the side wall  110   b  of the container  110  in the axial direction A. 
       FIG. 3  schematically shows an exploded illustration of the ice slurry production device  100  of  FIG. 2 . The heat exchanger device  200  is preferably integrated with the stirring device  500 , so that both can be inserted into the container  110  together during installation. A cover  114  of the container  110 , which is designed as a removable end wall  110   a , is preferably likewise integrated with the heat exchanger device  200  and/or the stirring device  500 . 
       FIG. 4  schematically shows another cross-sectional view of the ice slurry production device  100  of  FIG. 3 . The view does not show the stirring device  500 . The container  110  has a substantially hollow-cylindrical design. The heat exchanger plates  230  are disposed at radially constant distances from the side wall  110   b  of the container  110 . The heat exchanger plates  230  have the central through-passage  231  for the stirring shaft  520 . The central axis of the through-passage  231  is concentric with respect to the center axis of the container  110 . The interior space of the heat exchanger plates  230  has a flow field. The flow field is also defined by welds, depressions or other flow guide means  235  of the heat exchanger surfaces in the direction of the interior space. A slot  233  for a lateral installation of the stirring shaft  540  into the through-passage  231  extends radially outwardly from the central through-passage  231 . The feed  210  and the drain  220  are disposed between a radially outer edge of the heat exchanger plate  230  and the side wall  110   b  of the container  110 . The feed  210  and the drain  220  extend in the axial direction A. 
       FIG. 5  schematically shows a perspective view of another heat exchanger device  200  of the ice slurry production device  100 . In the embodiment shown here, the heat exchanger plates  230  have no slot  233 . The stirring shaft  520  is inserted axially through the through-passages  231  here. The flow  210  and the return  220  are partially accommodated in the heat exchanger plates  230 . The heat exchanger plates  230  have appropriate receptacles  234  for this purpose, as is shown in  FIG. 6 . 
       FIG. 6  schematically shows a top view onto the heat exchanger device  200  of  FIG. 5 . The receptacles  234  for the flow  210  and the return  220  are formed on an outer edge of the heat exchanger plate  230 , wherein these interrupt the edge. A feed  210  and/or return  220  received there protrudes over the edge in the direction of the side wall  110   b  of the container  110 . A fluidic connection of the interior space of the heat exchanger plate  230  to the feed  210  or the drain  220  is thus established without external connecting means, but is integrated. 
       FIG. 7  schematically shows a perspective view of another heat exchanger device  200  of an ice slurry production device  100 . Having a composition that is otherwise identical to that of the exemplary embodiment according to  FIGS. 5 and 6 , the embodiment according to  FIG. 7  includes receptacles  234  that do not interrupt the edge, but are designed as eccentric through-passages in the heat exchanger plate  230 . A feed  210  or drain  220  received there does not protrude radially over the edge of the heat exchanger plate  230 . Thus, the radial distance from the heat exchanger plates  230  to the side wall  110   b  of the container  110  must be dimensioned smaller. 
       FIG. 8  schematically shows a top view onto the heat exchanger device  200  of  FIG. 7 . The two receptacles  234  designed as through-passages penetrate the heat exchanger plate  230 , wherein the cross-section of the receptacle  234  is located completely inside the corresponding cross-section of the heat exchanger plate  230 . One embodiment of the ice slurry production device  100  including the heat exchanger device  200  according to  FIG. 4  is shown in  FIG. 9 . 
       FIG. 9  schematically shows a side view of the ice slurry production device  100  including the heat exchanger device  200  of  FIG. 8 . The feed  210  and the return  220  do not radially extend laterally from the heat exchanger plates  230 , but penetrate these. In this way, a uniform distance is achieved in the radial direction between the heat exchanger plates  230  and the housing  110 . The composition shown in  FIG. 9  essentially corresponds to the exemplary embodiment of  FIG. 1 . The ice slurry production device  100  has a more compact design, comprising a container  110  having two maintenance openings  113 . The heat exchanger device  200  comprises nine heat exchanger plates  230 . The stirring device  500  comprises ten stirring elements  540 . 
       FIG. 10  schematically shows a front view and a side view of a section of the ice slurry production device  100  of  FIG. 9 , however comprising a heat exchanger device  200  which has a slot  233  for installing the stirring shaft  520  and in which the flow  210  and the return  220  are disposed radially laterally from the heat exchanger plates  230 .  FIG. 11  schematically shows a partially exploded side view of the ice slurry production device  100  of  FIG. 10 . The relatively large radial distance between the heat exchanger plates  230  and the container  110  is apparent here, which corresponds at least to the width in the radial direction of the feed  210  or the drain  220 . 
       FIG. 12  schematically shows a cross-sectional view of another ice slurry production device  100 . The ice slurry production device  100  is designed larger than in the previous exemplary embodiment and accordingly comprises more heat exchanger plates  230 , which additionally have a larger heat exchanger surface, and accordingly more stirring elements  540 . The inclination regulating unit  400  comprises a pivot bearing  425 , one end of which rotatably mounts the container  110 . A linear actuator  426 , which is flexibly connected to the container  110 , is formed at an axial distance therefrom. The angle of inclination  410  can be adjusted by displacing the linear actuator  426 . 
       FIG. 13  schematically shows another cross-sectional view of the ice slurry production device  100 . The stirring shaft  520  is disposed in the central through-passage  231  of the heat exchanger plate  230 . The feed  210  and the drain  220  are disposed at a radial lateral distance from the heat exchanger plate  230  between the heat exchanger plate  230  and the side wall  110   b  of the container  110 . The stirring element  540  extends radially from the stirring shaft  520 . The stirring element  540  has a propeller-like or paddle-like design here. The profile of the stirring element  540  has an S-shaped cross-section. In addition, the stirring element  540  has a changed curvature in the axial direction A, so as to cause additional conveying in a further direction, this being the axial direction. In this way, the conveying device  600  is integrated into the stirring device  500 . Conveying thus takes place radially along the heat exchanger surfaces. As a result of the S-shaped curvature and the centrifugal forces, conveying takes place radially outwardly in the direction of the side wall  110   b  of the container  110 . In addition, conveying takes place in the axial direction A due to the axial curvature of the stirring element  540 . As a result, three-dimensional mixing and/or conveying takes place, which is additionally supported by the slanted position of the axis A or of the housing  110 . 
       FIG. 14  schematically shows a perspective view of the heat exchanger device  200  of the ice slurry production device  100  of  FIG. 13 . The flow  210  and the return  220  extend radially outside the heat exchanger plates  230 . The interior of the heat exchanger plates  230  has a flow field. The flow field has circular arc-like walls as flow guide means  235 , which extend from an inner side of the heat exchanger plate  230  to the opposite side. A flow path is thus defined for the refrigerant in the interior space. In addition, protrusions or depressions are provided in the interior space, which cause improved swirling of the refrigerant in the interior space. In this way, more effective heat transmission is achieved. 
     The device is suitable for a wide variety of application purposes. For example, the device can also be used with substance mixtures that separate in predetermined temperature ranges, for example a gas-liquid mixture into a liquid phase and a gaseous phase. The device is thus used with substance separation in sewage treatment plants, for example. 
     It goes without saying that a number of additional embodiments exist, although the above abstract and the detailed description of the figures describe only one exemplary embodiment. Rather, the detailed description above will be useful to a person skilled in the art as a suitable instruction for implementing at least one exemplary embodiment. Additionally, the above features of the invention can, of course, be used not only in the respectively described combination, but also in other combinations or alone, without departing from the scope of the invention. 
     LIST OF REFERENCE NUMERALS 
     
         
           10  ice slurry brine 
           20  support base 
           21  pedestal 
           100  ice slurry production device 
           110  housing (container) 
           110   a  end face 
           110   b  side wall 
           111  supply point 
           112  draw-off point 
           113  maintenance opening 
           114  cover 
           200  heat exchanger device 
           210  flow/feed 
           220  return/drain 
           230  heat exchanger plate 
           231  through-passage 
           232  intermediate space 
           233  slot 
           234  receptacle 
           235  flow guide means 
           400  inclination regulating unit 
           401  angle of inclination 
           420  inclination element 
           421  pedestal 
           425  pivot bearing 
           426  linear actuator 
           500  stirring device 
           510  stirring drive 
           520  stirring shaft 
           530  stirring motor 
           540  stirring element 
           600  conveying device 
           700  level regulating unit 
           710  brine container (first) 
           720  brine container (second) 
         A axis, axial direction