• 专利附录
  • 专利说明
  • 权利要求
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  • 优先权
    • 专利摘要:
    System (10) for cooling rooms (12), in particular storage rooms, comprising an open coolant circuit for circulating a coolant (14) from a cooling basin (16) to a room (12) to be cooled and back and a closed refrigerant circuit for circulating a refrigerant for cooling the coolant in the cooling basin (16), the refrigerant circuit being designed to build up an ice bank (48) from frozen coolant (14) in the cooling basin (16) when the system is in operation.
    公开号:CH715849A2
    申请号:CH00153/20
    申请日:2020-02-11
    公开日:2020-08-14
    发明作者:Peter Götz Klaus；Götz Stefan
    申请人:Götz & Klinger Gmbh；
    IPC主号:
    专利说明:

    TECHNICAL FIELD OF THE INVENTION
    The invention relates to a system and a method for cooling rooms, in particular storage rooms for food and drinks.
    BACKGROUND OF THE INVENTION
    For cooling rooms, especially storage rooms such as those used in the catering industry, it has long been known to direct a coolant circulating in a coolant circuit to a heat exchanger in the room to be cooled, where it is, usually through a fan is supported, interacts with the air in the room and extracts heat from it. The coolant itself is cooled by exchanging heat with a refrigerant.
    In particular, if the volume of space to be cooled is small, the cooling can also take place via a direct heat exchange between air and refrigerant, the refrigerant circulating in a closed circuit and thereby experiencing various changes in the physical state. Typically, it is compressed by a compressor, condensed in a condenser, expanded via a throttle and evaporated in an evaporator while absorbing heat, before it reaches the compressor again, as is done, for example, in commercially available refrigerators.
    For cooling larger volumes, a coolant is typically cooled by means of a heat exchanger through which a coolant flows, the coolant then serving to transport enthalpy along a temperature gradient from the room to be cooled to a point of lower temperature, namely the heat exchanger through which the coolant flows, which is known in a wide variety of forms and advantageously allows the use of coolants in the rooms to be cooled, which are less problematic for health and environmental reasons than refrigerants which, in contrast to the coolant, enthalpy in e.g. can also transport the cold cycle described above against the temperature gradient. WO 2017/143018 A1 describes in great detail the use of various coolants and refrigerants, which differ significantly from one another in terms of their environmental compatibility properties and their hazard potential for people.
    WO 2017/165764 A1 describes a further development of WO 2017/143018 A1, in which, in a heat exchanger cascade, e.g. Propane as a refrigerant and e.g. Ethane can be used as a coolant.
    For large cooling volumes on an industrial scale, so-called brine coolers with closed circuits and typically plate heat exchangers are also known in which so-called natural refrigerants, i.e. Naturally occurring, environmentally friendly refrigerants such as propane or CO2 can be used. However, the systems known to date are relatively expensive. In addition, there is the problem that the natural refrigerants are more environmentally friendly than those used previously, e.g. CFC-containing refrigerants, but their use nevertheless harbors health risks. Propane is flammable and CO2 is not poisonous in itself, but it hinders the uptake of oxygen and in high concentrations can lead to unconsciousness. The use of such natural refrigerants is therefore strictly regulated by legal requirements, so that their use in smaller cooling systems, such as those used in restaurants and hotels, is not worthwhile.
    From WO 2016/130537 A1 an arrangement for cooling a refrigerated vehicle provided with a liquid gas drive is known, in which the liquid gas to be evaporated for use in an engine is advantageous for cooling a coolant circulating in a closed circuit, which is used to cool the room of the refrigerated vehicle is used. The liquid gas is passed through a cooling basin via a heat exchanger so that it can extract heat from the coolant. If the cooling achieved in this way is not sufficient, an auxiliary cooling system starts up, in which a natural refrigerant such as e.g. Propane-operated closed refrigerant circuit supports the cooling of the coolant by the liquid gas.
    In addition, so-called wet coolers are known for cooling beverages such as beer in particular, in which a beverage line is arranged in a cooling basin typically filled with water and the water is cooled by means of a refrigerant that typically circulates in cooling coils also arranged in the cooling basin. Some wet coolers are operated in such a way that the water in the area of the cooling coils freezes in order to build up a so-called ice bank, which makes it possible to keep a more constant temperature in the cooling basin when a larger amount of drinks is to be cooled. So that the drinks do not freeze, such wet coolers are operated in such a way that the cooling of the water is switched off by means of a simple resistance measurement as soon as ice has built up with a certain strength, since the freezing point of the drinks to be cooled is typically slightly below that of water.
    Although the known systems and methods have proven themselves in practice, no corresponding systems and methods are known that allow in an economical and legal manner, natural refrigerants for cooling storage rooms, as they are typically in the Gastronomy and the hotel industry are used to use.
    DISCLOSURE OF THE INVENTION
    The invention has for its object to provide a system and a method for cooling rooms, in particular storage rooms, which make it possible in a simple and inexpensive manner to use natural refrigerants in a simple and economically particularly efficient manner in accordance with the statutory provisions and at the same time coolant should be used, which are significantly less problematic from an environmental and safety point of view than natural refrigerants.
    The object is achieved by a system with the features of claim 1 or a method with the features of claim 7. Advantageous configurations and developments are the subject of the subclaims.
    A system according to the invention comprises an open coolant circuit for circulating a coolant from a cooling basin to a room to be cooled and back and a closed refrigerant circuit for circulating a refrigerant for cooling the coolant in the cooling basin, the refrigerant circuit being designed to operate the Plant to build an ice bank from frozen coolant in the cooling basin. An ice bank is understood to be a region of frozen coolant that effectively acts as a "cold store" (i.e., due to the change in state, can absorb more heat than liquid coolant before there is a change in temperature), but which does not hinder the circulation of non-frozen coolant.
    The fact that the coolant circuit is open and the cooling basin is not particularly encapsulated results in a particularly maintenance-friendly design of the system because, as will be explained below, moving parts of the system can be easily accessible in or above the cooling basin.
    An important feature of the invention is that an ice bank is built from frozen coolant in the cooling basin during operation of the system. Surprisingly, it has been shown that a whole range of energetic and practical advantages is thereby achieved. It is known to detect the temperature of the coolant in the cooling basin. If this exceeds a certain upper limit temperature, measures such as according to the aforementioned WO 2016/130537 A1, the operation of a heat exchanger with liquid gas or the connection of an additional refrigerant circuit attempts to lower the temperature of the coolant in the cooling basin until a lower limit temperature is reached. However, it has been shown that if the temperature in the room to be cooled suddenly increases significantly, e.g. Objects heated by solar radiation such as beverage barrels are set, it can take a very long time until such cooling is able to cool the coolant, which has been heated by the heat exchange with the room to be cooled, again in the desired manner.
    [0015] Coolant flowing back from the room to be cooled runs into the cooling basin, where it partially mixes with the coolant located there, while at the same time coolant is sucked out of the cooling basin and fed to the room to be cooled.
    In order to keep the influence of warm coolant flowing into the cooling basin low, the procedure so far had to be such that the amount of the coolant in the cooling basin was much greater than the amount in a line from the cooling basin to the room to be cooled and coolant flowing back again.
    Alternatively or additionally, the refrigerant circuit had to be dimensioned accordingly so that, if necessary, the coolant could be cooled very quickly in the cooling basin by the refrigerant. In Germany, however, e.g. Only cooling systems are permitted for the catering sector which, due to their design, only use relatively small amounts of natural refrigerants, e.g. only 150 g propane, which is usually not enough to always ensure sufficient cooling of the coolant with typical capacities of the storage rooms in question.
    The ice bank constructed according to the invention now acts advantageously as a cold store, so that it can also be used with small amounts of natural refrigerant, e.g. significantly less than 150 g propane, it is possible to operate a system according to the invention without any problems. If it actually happens that more heat is transported via the coolant flowing to the cooling basin than can be carried away by the refrigerant in the cooling circuit, this heat is first used to partially defrost the ice bank without the temperature in the cooling basin immediately noticeably changing increased that the coolant led from the cooling basin to the room to be cooled would no longer have a cooling effect. The ice bank according to the invention thus advantageously allows not only to use a refrigerant circuit with a very small volume compared to the prior art, but at the same time also to significantly reduce the volume of the coolant circuit, in particular the volume of the cooling basin.
    In a preferred embodiment of the invention, the coolant is a brine, in particular a glycol mixture, and the refrigerant is a natural refrigerant, in particular propane.
    In a further preferred embodiment, the freezing point of the coolant is set to about -3 to -10 ° C, in particular about -5 to -7 ° C. It has been shown that these operating conditions create optimal conditions for cooling the typical storage rooms in question here and that it is then possible to build an ice bank in the cooling basin in an energetically favorable manner.
    [0021] Further details and advantages of the invention emerge from the following, purely exemplary and non-limiting description of various embodiments and implementation forms in conjunction with the drawing comprising one figure.
    BRIEF DESCRIPTION OF THE DRAWING
    [0022]<tb> Fig. 1 <SEP> shows, in a highly schematic manner, the basic structure of a system according to the invention.
    DESCRIPTION OF PREFERRED EMBODIMENTS AND EMBODIMENTS
    In Fig. 1, designated in its entirety by 10 system for cooling a room 12, in particular a storage or so-called. Cold room, is shown, which comprises an open coolant circuit in which a coolant 14 between a cooling basin 16 and the space to be cooled 12 circulates. For this purpose, it is pumped out of the cooling basin 16 by means of a pump 18 and guided via the section of a coolant line forming a flow 20 to a heat exchanger 22, which, depending on the design of the system, can be arranged in or on the space 12 to be cooled, where it is carried along Air located in the room 12 or blown into the room 12, preferably - as symbolically indicated by the fan 24 - fan-assisted via known heat exchange surfaces 26 through which the coolant flows and symbolically indicated by the lines enters into heat exchange and thus extracts heat from the air . It should be emphasized at this point that the air can of course also be air that is extracted from the room.
    The coolant heated in this way then flows back via the section of the coolant line forming a return 28 to the cooling basin 16, where it mixes with the coolant 14 located there. In order to prevent colder and warmer zones from forming in the cooling basin 16, at least one stirring device 30 is provided according to the invention, which can in particular be designed for permanent operation. An optionally provided second stirring device can e.g. can be provided on the intake port 32 of the pump 18, which is only shown symbolically here, and be designed in such a way that it only starts when the pump 18 pumps coolant 14 into the supply line 20. As a result of the stirring, the coolant 14 is in motion, as symbolically indicated by the restless coolant surface 36.
    The coolant is a brine, i. an aqueous solution whose freezing point is below that of water. The brine can in particular be a glycol-water mixture, preferably a mixture of water and propylene glycol, the freezing point of which is preferably set to about -3 to -10.degree. C., preferably about -5 to -7.degree .To cool the coolant 14 located in the cooling basin 16, a refrigerant circuit is provided in which a refrigerant, here a natural refrigerant, in particular propane, circulates in a closed line 40 from a compressor 38 and is initially compressed by the compressor 38 and is liquefied in a liquefier 42 while releasing heat to the environment.
    Via a throttle 44, which is e.g. may be an expansion valve or a capillary tube, the refrigerant is expanded and then evaporates in the so-called cooling coils 46 shown here in section, of which only a few have been provided with reference numerals for reasons of clarity. Depending on the design of the cooling basin, it can be a single line laid in several turns around the cooling basin or within it, or several individual parallel lines branching off from a common distributor, which then open into a common collecting pipe. The precise design of the cooling coils can advantageously be adapted by a person skilled in the art, depending on the particular application. It is important that the arrangement of the cooling coils in conjunction with the selected coolant and refrigerant and the dimensioning of the system allow the system to be operated in such a way that a so-called ice bank 48 is built up during operation in the vicinity of the cooling coils 46 inside the cooling basin, as indicated, which advantageously serves as a cold store and prevents, for whatever reasons, strongly heated coolant from overloading the cooling system, thus ensuring that cooled coolant is always fed to the heat exchanger 22 under typical operating conditions.
    So instead of increasing the volume of the cooling basin 16 as before, so that even when relatively warm coolant flows back from the space to be cooled into the cooling basin, where it mixes with the cooled coolant, the overall mixture is still sufficiently cold , according to the invention, the refrigerant circuit can be set so that the coolant 14 in the cooling basin 16 at least in the vicinity of the cooling coils 46 cools to temperatures below its freezing point, but without causing the coolant to freeze completely. If the freezing point of the coolant is e.g. set to -6 ° C, the cooling circuit can e.g. operated in such a way that it starts to cool from a temperature of -4 ° C, which is measured by means of at least one temperature sensor 50 at at least one point in the cooling basin 16, and then when e.g. -10 ° C the cooling stops. Unlike e.g. With wet coolers, the cooling is not stopped when a layer of ice has formed, but rather it is cooled over a certain selectable temperature range.
    In the vicinity of the cooling coils 46, ice forms, the so-called ice bank 48, to whose thawing due to the change in physical state significantly more energy is required than if only liquid coolant 14 would simply have to be heated. It has been shown that with such an ice bank 48 it is also possible to absorb large temperature differences between the flow to the space 12 and the return from the space 12 without the refrigerant circuit being overloaded.
    The plant shown can e.g. work as follows: A user selects a desired temperature in room 12 by means of a corresponding setting unit, which is reported to a central control unit 54 via one or, depending on the size of the room, several temperature sensors 52. The control unit 54, which is e.g. can be a microcontroller, is connected in a manner known per se to the pump 18, the fan 24 and the compressor 38 and can control these devices depending on the temperature. If an above-mentioned optionally possible stirrer assigned to a suction port of the pump 18 is provided, this can start automatically when the pump 18 is switched on, or it can also be controlled by the control unit 54. The stirrer 30, which is actually designed for continuous operation, can also be controlled via the control unit 54, e.g. change the speed in extreme conditions or switch the system on and off centrally. If the temperature conditions in the room 12 do not change, e.g. If a door is opened or objects are brought in, the cooling system can be operated with low power provided the room is well insulated, in order to compensate only for the natural warming of the room 12 due to heat exchange with the surroundings. For this purpose, coolant is fed via the supply line 20 to the heat exchanger 22, from where it is slightly warmed back into the cooling basin 16 via the return line 28, with heat being extracted from the air in the room 12. If more cooling is required, the control unit 54 can increase the output of the pump 30 and, if necessary, of the fan 24.
    The temperature in the cooling basin 16 is detected by means of one or more temperature sensors 50 and also reported to the control unit 54. If this temperature rises above an upper limit temperature, e.g. -4 ° C, the control unit 54 switches on the compressor 38 so that the cooling basin is cooled until a certain lower limit temperature, e.g. -10 ° C is reached. The ice bank 48 builds up up to a certain value, the operating parameters being selected so that the coolant 14 does not completely freeze through. The exact operating parameters depend on the conditions prevailing at the location where the system is used, but can easily be determined in a test run of the system. Typical operating sizes for cooling a catering cold room are, for example: Cooling basin content around 40 to 50 liters, capacity of the coolant line to and from the room to be cooled around 5 - 10 liters, freezing point of the coolant -6 ° C, refrigerant in the refrigerant circuit around 80 to 120 grams.
    If much or strongly heated coolant flows through the return line 28 back to the cooling basin 16, which brings more thermal energy with it than can be removed via the cooling coils 46, the ice bank 48 is gradually reduced, but the temperature in the cooling basin 16 is nevertheless advantageously kept sufficiently cold so that cold coolant can continue to flow via the flow line 20 to the space 12.
    Numerous modifications and developments are possible within the scope of the idea of the invention, e.g. refer to the design of the open coolant circuit. For example, if several smaller units e.g. are to be cooled in the form of storage compartments, instead of the one open circuit shown, several open circuits can be provided, each of which cools a storage compartment. It is also possible to use several simple control units or controls instead of a central control unit, with the temperature sensor (s) 52 in the room (s) 12 to be cooled then influencing the start-up and / or the pumping capacity of the pump 18 during the Temperature sensors 50 influence the start-up and / or the performance of the compressor 38.
    REFERENCE LIST
    10 cooling system 12 room 14 coolant 16 cooling basin 18 pump 20 flow 22 heat exchanger 24 fan 26 heat exchanger plates 28 return 30 stirrer 32 suction nozzle 36 coolant surface 38 compressor 40 refrigerant line 42 condenser 44 throttle 46 cooling coils 48 ice bank 50 temperature sensor 52 temperature sensor 54 control unit
    权利要求:
    Claims (12)
    [1]
    1. System for cooling rooms, in particular storage rooms, comprising- An open coolant circuit for circulating a coolant from a cooling basin to a room to be cooled and back and- A closed refrigerant circuit for circulating a refrigerant for cooling the coolant in the cooling basin,- The refrigerant circuit is designed to build up an ice bank from frozen coolant in the cooling basin when the system is in operation.
    [2]
    2. System according to claim 1, characterized in that the coolant is a brine, in particular a glycol mixture, and / or the refrigerant is a natural refrigerant, in particular propane.
    [3]
    3. Plant according to claim 1 or 2, characterized in that the freezing point of the coolant is set to about -3 ° C to -10 ° C, in particular about -5 ° C to -7 ° C.
    [4]
    4. Systems according to one of claims 1 to 3, characterized in that the coolant circuit comprises a line from the cooling basin to the space to be cooled and back, the volume of the cooling basin being a multiple of the volume of the line.
    [5]
    5. System according to one of claims 1 to 4, characterized in that about 50 to 150, preferably about 80 to 120 grams of refrigerant circulate in the refrigerant circuit.
    [6]
    6. Plant according to one of claims 1 to 5, characterized in that at least one stirring device is arranged in the cooling basin.
    [7]
    7. Plant according to claim 6, characterized in that at least two stirring devices are arranged in the cooling basin, one of which is designed for permanent operation, the other for temporary operation.
    [8]
    8. A method for cooling rooms, in particular storage rooms, comprising the steps- the circulation of a coolant in an open coolant circuit from a cooling basin to a room to be cooled and back,- The circulation of a refrigerant in a closed refrigerant circuit for cooling the coolant in the cooling basin and- Building an ice bank from frozen coolant in the cooling basin.
    [9]
    9. The method according to claim 8, characterized in that a brine, in particular a glycol mixture, and / or a natural refrigerant, in particular propane, is used as the coolant.
    [10]
    10. The method according to claim 8 or 9, characterized in that the freezing point of the coolant is set to about -3 ° C to -10 ° C, in particular about -5 ° C to -7 ° C.
    [11]
    11. The method according to any one of claims 8 to 10, characterized in that the refrigerant is circulated so that the temperature in the cooling basin is between about 0 ° C and -10 ° C, preferably between about -4 ° C and -10 ° C emotional.
    [12]
    12. The method according to any one of claims 8 to 11, characterized in that the liquid coolant is mixed in the cooling basin by permanent stirring.
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    同族专利:
    公开号 | 公开日
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    DE102019103378|2019-02-11|
    DE102019115158|2019-06-05|
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