Method for cooling at least one refrigerant and / or at least one refrigeration transfer medium in an open process

Abstract

The invention relates to a method and to a system for cooling at least one refrigerant and / or at least one refrigeration transfer medium in an open process with a continuous or discontinuous mode of operation, wherein at least one first substance flow (1) in the form of the refrigerant and at least one second substance flow (2) of the refrigeration transfer medium are conveyed under pressure to at least one apparatus (3) and combined in the apparatus (3), the two substance flows (1, 2) expand and cool down in and / or as they exit from the apparatus (3), as a result of which ice, slurry ice / particles of ice, snow, cold water or other refrigeration transfer media or combinations or mixtures / suspensions thereof with a low temperature are generated, and the flow (1 / 2) comprising the substance flows (1) and (2) exiting from the apparatus (3) is supplied at least to a container / refrigeration storage device (4) having a storage function and the second substance flow (2) is taken from the container / refrigeration storage device (4) in order to implement at least one cooling task (K) and / or the cooling task (K) is executed with at least one heat transfer medium in / at the container / refrigeration storage device (4).

Description

[0001] Method for cooling at least one refrigerant and / or at least one coolant in an open process

[0002] The invention relates to a method and a system for cooling at least one refrigerant and / or at least one coolant in an open process according to the preamble of the 1st and 15th patent claims and to the use thereof.

[0003] From JP 2009-97793 A, a method and apparatus for producing spherical ice particles are known, which are used, for example, as abrasives or for jet cleaning equipment. A liquid is fed into a thin tube with low thermal conductivity at a flow velocity below the laminar range, and the liquid is slowly cooled at a cooling rate of 0.2 °C / min or less to a temperature approximately 5 °C to 10 °C below the freezing point of the liquid. Droplets of the supercooled liquid are then continuously released into an atmosphere below the freezing point of the liquid, and the droplets become approximately spherical due to the surface tension generated in the droplets. Spherical ice particles are then produced by contacting the droplets with a cryogenic gas, ice nuclei, or a mixture of cryogenic gas and ice nuclei.

[0004] Humid air is used to generate particles.

[0005] The focus is on the production of particles for use in mechanical process engineering.

[0006] Due to the subcooling of 5...10 K (Kelvin!), the process can only work up to a temperature range of -10 °C.

[0007] The effect of supercooling is also used. However, this effect can only be used if the water velocity is very low and the flow is not disturbed (no turbulence, no vortex, no disturbances, no sharp changes in direction, etc.).

[0008] The use of spherical ice particles for a cooling purpose is not intended. The focus of US 4475688 A is on the production of artificial snow, in which a spray of water droplets is exposed to an electrostatic field. The ambient air temperature should not be more than slightly above 0 °C and preferably below 0 °C. This process is also not suitable for a cooling purpose and is also not intended, and is very energy-intensive due to the necessary electrostatic field. A method and device for producing artificial snow are also described in EP 1473528 A1. Water is injected into a gas stream with temperatures below the freezing point of water and then applied to the surface to be snowed. For this purpose, water is atomized in a closed space in which liquefied air,Air components or mixtures thereof are injected. The formed crystals are fed to a separator, and a fraction of the crystals with a larger diameter is applied to the area to be snowed, while a fraction with a smaller particle diameter is returned to the enclosed space as crystallization nuclei. CO2 snow can be added. Heating is necessary to prevent clogging, blockages, etc. Furthermore, this solution considers heat transfer on the slope. However, this is not relevant for the implementation of a cooling task. This system is also neither suitable nor intended for the implementation of a cooling task. All of the aforementioned solutions for ice ball or snow production are for the generation or storage of cold, for the fulfillment of a cooling task.for the utilization of the heat generated in the process or for operation as a grid-reactive system. Furthermore, the above-mentioned publications do not provide any information on the following features: - no specification of the process parameters temperature and pressure - no (large) compressors with a significant pressure increase are used, only fans - the heat generated by the (low) compression process is not utilized - no cold storage is used to realize a cooling task - Furthermore, with the above-mentioned solutions, it is not possible to realize a recovery of the technical work for the compression through simple throttling points and / or turbines. The storage of cold water and water ice, which is not known from the above-mentioned solutions, has many (theoretical) advantages (e.g. ecological storage material,Pumpability of ice slush). However, ice slush or snow storage systems have not been successful for various reasons (e.g., too expensive plant technology, too low coefficients of performance). Various technologies cannot be scaled to large capacities, or when scaled to large capacities, no cost reductions or efficiency improvements could be achieved. Snow storage systems often require cold outside air temperatures or long winter periods for snow production. Seasonal cold storage with snow has proven to be very challenging in initial projects. Therefore, the process-based production of cold water, ice slush,Snow or similar material systems are required. Solutions for large-scale storage (e.g., larger than 1000 m³) for short- and long-term storage of fluid material systems below -10 °C for cooling purposes do not exist, both theoretically and practically. Furthermore, conventional refrigeration machines with currently approved refrigerants are often used for cooling. These are harmful to the climate and the environment. New refrigerants are often flammable, explosive,toxic (or their degradation products), etc. Therefore, a transition to environmentally friendly refrigerants and coolants is necessary. The use of air as a refrigerant and coolant has been known for a long time. Open cold gas processes were used to cool bearings. This process was replaced by the use of refrigeration machines with cold vapor processes. Today, cold air processes are only used in niche applications (e.g., cooling passenger compartments). An optimization of the cold air process is known from the publication DE 4127224 A1. This solves the problem of moisture separation. Approaches to significantly increase energy efficiency are not shown. Furthermore, processes for ice slurry production using negative pressures (ice production near the triple point of water or water with accompanying substances) are associated with the problem that vapors with very low densities must be compressed.which is disadvantageous both energetically and technically. Higher pressure differences can in principle be achieved in the overpressure range. This brings significant advantages for process control and the achievable process parameters. Considering the system characteristics of refrigeration and ice production systems, no reactive (e.g., absorption of negative control and balancing energy) and black-start capable systems (e.g., start-up after a power failure) or discontinuous processes are known. This means that known systems and systems do not provide solutions for increasing energy efficiency and flexibilizing plant operation. The object of the invention is to develop a system and a method for cooling at least one refrigerant and / or at least one coolant in an open process for industrial or technical applications.with which high cooling capacities and high ice production can be achieved using an ecological or accumulating refrigerant and coolant, whereby very high storage loading capacities, very high storage unloading capacities or system integration, possibly a direct application to, for example, foodstuffs or a supply via pipelines (e.g., district cooling) or for sports purposes, especially for winter sports, can be realized and only low operating and maintenance expenditure is required. It should be possible to provide ice, ice slush / ice particles, snow, cold water or combinations or mixtures / suspensions thereof from 20 °C to -200 °C and to use the system as a grid-reactive system for providing positive and / or negative control and / or balancing power. This object is achieved with the features of patent claims 1, 15 and 32. Advantageous embodiments arise from the subclaims. The method implementation of a cooling task,wherein the cooling of at least one refrigerant and / or at least one coolant is carried out in an open process with a continuous or discontinuous operation, wherein at least a first material stream in the form of the refrigerant in the form of compressed air and / or compressed process gas and at least a second material stream of the coolant consisting of water and / or water with freezing point lowering substances and / or other coolants and / or mixtures / suspensions thereof are conveyed by at least one pump under pressure to at least one apparatus and brought together in the apparatus, wherein upstream of the apparatus at least one compressor compresses and conveys the first material stream at a pressure of 1.1 bar to 2500 bar and the first material stream is passed through at least one cooler / heat exchanger and at least one pump conveys the second material stream and realizes a pressure increase to 1,1 bar to 2500 bar and the refrigerant of the first material flow and the coolant of the second material flow relax and cool in and / or upon exiting the device, whereby ice, ice slush / ice particles, snow, cold water or other coolants or combinations thereof or mixtures / suspensions with a low temperature are produced and the flow of the material flows exiting the device is fed to at least one container / cold storage device with storage function,in and / or upstream of the container, a phase separation of the first material flow and the second material flow takes place and the first material flow is discharged from the container / cold storage to the environment and / or is used for pre-cooling the second material flow and / or cools the compressed first material flow and the second material flow is removed from the container / cold storage to implement at least one cooling task and / or the cooling task is implemented with at least one heat exchanger in / on the container / cold storage.

[0009] The discontinuous process for cooling at least one refrigerant is primarily realized by the integration of at least one container in the form of a storage tank for the refrigerant, which can also ensure, for example, a black start capability (starting a system after a partial or complete failure of the energy and / or material supply).

[0010] The first stream is fed into the device via at least one compressor and at least one cooler / heat exchanger. This ensures the required pressure upon entry into the device and reduces the temperature of the first stream after the compressor, so that the temperature upon entry into the device should preferably not exceed 50 °C.

[0011] Preferably, before being fed to the apparatus, the first material stream is recooled by means of at least one recooler, wherein the heat is released to the environment and / or wherein the cold exhaust air from the apparatus or a cyclone associated with the apparatus and / or at least a partial stream is used after expansion of the first material stream.

[0012] The following modifications to the first material stream are advantageously carried out, whereby the measures can be implemented individually or in various combinations: a. single- or multi-stage compression up to a maximum final compression pressure of approximately 2500 bar, b. parallel connection of compressors, c. with and without intermediate cooling, d. use of one or more refrigerant dryers (e.g. sorptive drying, below the dew point).

[0013] If necessary, at least one oil separator can still be used.

[0014] Furthermore, it is possible to pass the first material stream through at least one expansion machine and / or at least one expansion device before entering the apparatus, thereby expanding and cooling the first material stream. The expansion machine then drives, for example, a generator for power generation and / or the compressor(s) directly or via a gearbox and / or other consumers.

[0015] The second material stream is fed to the device from the container / cold storage and / or from the pipeline network and / or from another storage facility and / or from a body of water and / or other water sources.

[0016] Preferably, the second material stream passes through a heat exchanger before being fed to the apparatus.

[0017] The process gases used in the process are particularly

[0018] Gases released into the environment, technical gases (e.g. nitrogen),

[0019] Exhaust and exhaust air from air conditioning systems or technological installations, flue gases,

[0020] Mixtures of some or all of the above-mentioned gases, which are supplied to the apparatus in compressed form.

[0021] Preferred coolants are water, oils, silicones, alcohols, glycols, other organic or inorganic fluids, other technical coolants or any mixtures or suspensions thereof.

[0022] It is possible to use freezing point lowering substances in the form of alcohols, glycols, salts, sugars, organic and inorganic substances or

[0023] Mixtures of some or all of the above substances may be used.

[0024] If coolants in the form of organic or inorganic substances such as oil, silicone, alcohol, glycol are used, freezing point lowering substances in the form of solid additives and / or gaseous additives, phase change materials or mixtures of some or all of the aforementioned substances can be used if necessary.

[0025] Other coolants for low temperatures can include oils and / or silicones (organic substances) with or without additives. Furthermore, mixtures / suspensions such as water and freezing-point-lowering substances and / or substances that promote phase changes, such as nucleating particles and / or droplets, can be used as coolants, especially for operation at storage temperatures well below 0 °C.

[0026] The second material stream is preferably fed to the apparatus under a pressure increase from approximately ambient pressure to a high pressure of up to 2500 bar and, if necessary, under cooling with at least one heat exchanger to approx. 0 °C.

[0027] The supply of material stream 1 to the apparatus is realized in particular with cooled and / or compressed and / or expanded air or process gases (possibly different phases), preferably with prior cooling between -200 °C and 50 °C.

[0028] According to the process, the coolant is discharged directly or indirectly from the container to realize the cooling function.

[0029] The plant for carrying out the method according to the invention for realising a cooling task and for cooling at least one refrigerant and / or at least one coolant in an open process with a continuous or discontinuous mode of operation comprises at least one apparatus which has at least one first feed for at least one first material stream of a refrigerant and at least one second feed for at least one second material stream of a coolant consisting of water and / or water with freezing point lowering substances and / or other coolants, wherein the apparatus has at least one chamber in which the first and second material streams can be combined, expanded and cooled, wherein at least one container / cold storage device with a storage function is connected to the apparatus, to which the stream emerging from the apparatus can be fed,wherein a phase separation of the refrigerant and the coolant from the supplied stream can be realized in the container, and that the container / cold storage device has at least one outlet for the refrigerant and, to realize the cooling task, at least one further outlet for the coolant and / or at least one heat exchanger. The second material stream can be supplied to the apparatus from the container / cold storage device and / or from the pipeline network and / or from a storage container and / or a storage basin and / or a natural body of water. Furthermore, at least one secondary material stream consisting of a coolant can lead from the container to the apparatus. The system according to the invention is equipped in particular: - with the apparatus (3) for combining and subsequently expanding the first and second material streams to produce ice, ice slush / ice particles, snow, cold water, or combinations or mixtures / suspensions thereof,- with the tank for phase separation of the first and second material streams from the stream that is fed from the apparatus into the tank, - with at least one second heat exchanger for pre-cooling the second material stream to a temperature of 30 °C to 0 °C before it is fed to the apparatus, - with at least one pump for conveying the second material stream and for increasing the pressure to 1.1 bar to 2500 bar upstream of the apparatus, - with at least one first heat exchanger for recooling the first material stream to a temperature between -40 °C and 50 °C upstream of the apparatus, - with at least one compressor for compressing and conveying the first material stream and for achieving a pressure of 1.1 bar to 2500 bar upstream of the apparatus. Advantageously, several compressors and coolers are arranged in the coolant supply line / in the first material stream 1 of the coolant to the apparatus,wherein at least one compressor is assigned a heat exchanger / recooler. Furthermore, the system comprises at least one expansion machine and / or at least one expansion device in the first material stream before it is fed to the apparatus. This cools the first material stream before it is introduced into the apparatus. The expansion machine, e.g., a turbine or a displacement machine, can directly and / or indirectly drive a generator for power generation and / or the compressor(s).

[0030] Furthermore, a storage / intermediate storage unit for temporarily storing the refrigerant of the material flow is advantageously integrated into the material flow 1 of the refrigerant, preferably upstream of the expansion machine.

[0031] If, for example, the entire system was out of operation or in the event of a brief power failure, pressurized refrigerant can be fed into the circuit via the intermediate storage tank, which can then drive the turbine and then the generator to generate electricity, thereby driving the pump(s) and / or compressor.

[0032] In the container / cold storage unit, the refrigerant of the first stream is separated in an upper area, and the coolant of the second stream is separated in a lower area. The coolant is released into the environment, and the coolant or storage unit is discharged directly or indirectly.

[0033] A cyclone for phase separation of the refrigerant and the coolant can be assigned to the container / cold storage unit, or the cyclone can also be integrated into the container.

[0034] Furthermore, the container may have a tangential or substantially tangential feed for the stream supplied from the apparatus, thereby promoting phase separation.

[0035] It is advantageous if areas of the system that are prone to icing or where there is a risk of icing are provided with additional heating and / or heat exchangers.

[0036] Preferably, the apparatus is equipped with a heat exchanger and / or an additional heater, which in particular have one or more heating areas.

[0037] The additional heating is provided, for example, by means of electrical resistance and / or microwaves and / or induction heating and / or a warm material flow. Furthermore, the apparatus can have additional cooling to dissipate heat generated during reactions and / or dissolution processes.

[0038] The at least one apparatus has at least one inlet for the first material stream and at least one or more inlets for the second material stream and, if applicable, for the secondary circuit(s).

[0039] Means for generating a swirling flow can be arranged in the apparatus, which promotes the merging of the material flows.

[0040] The means of the apparatus for generating the flow with swirl can be designed with or without rigid or moving internals for influencing the flow.

[0041] Furthermore, it is possible for a continuous or pulsating flow to pass through the device and for further flow effects such as turbulence, instability, boundary layer effects, subsonic and supersonic flow to be realized if required.

[0042] The method and device according to the invention can also be used as a heat pump system and / or as a combined cooling and heating system.

[0043] With the solution for generating cold according to the invention, cold water, aqueous solutions, water ice, ice slush, snow and mixtures / suspensions thereof can be generated, if necessary using other substances (e.g. alcohols, glycols, salts, sugars, solid additives, gaseous additives, phase change materials) and / or other coolants (e.g. oils, silicones).

[0044] This is preferably done for air conditioning, technological cooling (normal cooling and low-temperature cooling), winter sports (snow and ice production), power plant processes and the like.

[0045] The system according to the invention can be used to realize short-term storage (e.g. a few minutes up to a few days) and / or long-term storage (e.g. several months).

[0046] The storage structures used for this purpose - here containers / cold storage - can be, for example, tanks in the form of pressure vessels or flat-bottom tanks, but also basins, dumps, underground spaces or other structures that are suitable for storing the coolant.

[0047] It is possible to utilize the waste heat generated during the implementation of the process according to the invention, e.g., for heating purposes, for providing process heat, for charging thermal energy storage systems (heat storage systems) with warm water, hot water, steam, and other heat transfer media; but also for generating cold with absorption chillers, adsorption chillers, steam jet chillers, or as a heat source system for another heat pump.

[0048] Furthermore, the system can be used as a grid-reactive system to provide positive and / or negative control and / or balancing power.

[0049] The solution according to the invention can also be used as a water reservoir (secondary use) for fire-fighting purposes, for irrigation, for technological or other processes.

[0050] The invention allows for refrigeration systems with medium to very high cooling capacities, and primarily uses environmentally friendly, inexpensive, and readily available materials as refrigerants and coolants. This allows for safe implementation and operation, and therefore the use of the system is associated with extremely low or no risks.

[0051] By using air as a refrigerant in a so-called open cold gas process, known problems with conventional refrigerants are eliminated. Furthermore, unlike conventional refrigerants, the refrigerant used in the invention has unlimited availability.

[0052] The system components used are familiar (multi-stage) compressors with intercooling, which also serve to supply heat. Furthermore, familiar heat exchangers and expansion machines, such as a gas turbine, are used, which, for example, drives a generator that can serve to at least partially supply the system with energy. Conventional tanks and reservoirs, or other storage spaces, can also be used. In particular, the use of water as a coolant and the use of water (or similar material systems) in an open or closed process are possible.

[0053] In neighborhoods (residential areas, industrial areas), a suitable heat source is often lacking. In these cases, a storage facility (e.g., a tank, a reservoir) can be used as a heat source. Seasonal charging and discharging is also conceivable.

[0054] The invention enables cost-effective storage in tanks, basins, dumps, underground spaces and, if necessary, further provision in summer when there is a water shortage (dual benefit).

[0055] Since cold gas processes have low performance figures, it is advantageous to simultaneously utilize the waste heat.

[0056] The system according to the invention can be easily scaled to medium to large cooling capacities and high ice production rates.

[0057] It is possible to use open tanks and basins for storage through an open process to achieve very high storage capacities.

[0058] The system requires only minimal operating and maintenance effort.

[0059] The refrigerants and coolants used ensure excellent phase separation. This makes it possible to solve various problems related to ice formation, monitoring, measurement, control, and the modular design of ice production.

[0060] Further advantages include the very high storage charging capacities and the very high storage discharging capacities and the possible system integration, possibly direct application to, for example, foodstuffs or the supply in pipelines (e.g., use for district cooling) or for sports purposes, for example, for winter sports for ice and / or snow production or for cooling.

[0061] The method and the system according to the invention are based primarily on the following circuit / sub-processes

[0062] • Pressure increase of, for example, a water flow (material flow 2), e.g. from a cold storage or a cooling network from approximately ambient pressure to a high pressure, if necessary cooling down to approximately 0 °C, • Supply of cooled and / or compressed and / or expanded air (material flow 1, possibly different phases) and / or another material (material flow 2), preferably with prior cooling below 0 °C,

[0063] • Contact of the two material flows (e.g. with apparatus) and subsequent expansion to produce a cooled material flow 1 and 2, preferably with production of cold water and / or aqueous solutions and / or water ice and / or snow as well as their mixtures / suspensions, if necessary using other substances (alcohols, glycols, salts, sugars, solid additives, gaseous additives, phase change materials) and / or other coolants (e.g. oils, silicones),

[0064] • Phase separation in front of or in a container / storage tank, removal of the gaseous phase and collection of the predominantly solid / liquid phase (cold water and / or aqueous solutions and / or water ice and / or snow as well as their mixtures / suspensions, if necessary using other substances (e.g. alcohols, glycols, salts, sugars, solid additives, gaseous additives, phase change materials) and / or other coolants (e.g. oils, silicones)),

[0065] • direct and / or indirect supply of a cooling task (at least one cooling consumer) and / or

[0066] • direct and / or indirect discharge of the tank / storage tank for direct and / or indirect supply to at least one cooling consumer.

[0067] A cooling task in the sense of producing ice / snow is also possible with the solution according to the invention at outside temperatures above 0 °C.

[0068] The solution according to the invention, for example, uses air as a refrigerant, thus circumventing the misconception that air is a "bad refrigerant." While the industry offers new refrigerants, these have negative environmental impacts (see, for example, https: / / www.umweltbundesamt.at / umweltthemen / stoffradar / pfas).

[0069] Solutions must therefore be found to use renewable electricity efficiently and as locally as possible. Furthermore, systems will be needed in the future that, in addition to storage, offer a rapid response to fluctuations in the power grid.

[0070] The solution according to the invention can be implemented on an industrial scale and with expectedly relatively low investment costs (especially compared to hydrogen technologies). The invention encompasses a relatively broad range of applications, which clearly distinguishes it from the particle generation and artificial snow production described in the prior art.

[0071] The invention is explained in more detail below using exemplary embodiments and the accompanying drawings. They show:

[0072] Figure 1 Schematic diagram of a system according to the invention,

[0073] Figure 2 Schematic diagram of another variant of the system

[0074] Figure 3 Schematic diagram of a further variant of the plant according to the invention with a secondary circuit of material flow 2,

[0075] Figure 4 shows a variant of the system with a multi-stage compression and cooling of the material flow 1 as well as a storage for the material flow 1 / refrigerant storage / compressed air storage, for example for a black start capability,

[0076] Figure 5 shows a first variant of the apparatus with a feed for the material flow 1 (refrigerant) and a feed for the material flow 2 (coolant),

[0077] Figure 6 shows a second variant of the apparatus with one feed for the material flow 1 (refrigerant) and two feeds for the material flow 2 (coolant),

[0078] Figure 7 shows a third variant with several devices connected in parallel.

[0079] According to Figure 1, the system has a first material stream 1 with at least one or consisting of at least one refrigerant and a second material stream 2 with at least one or consisting of at least one coolant.

[0080] The system is further equipped with an apparatus 3 and an adjoining container 4 with storage function.

[0081] In the open process, tank 4 is preferably filled first with coolant (for material stream 2).

[0082] A refrigerant 1, preferably air, for example, is conveyed via a compressor 5 and a first heat exchanger 1.1 and the coolant 2 is conveyed from the container 4 via a second heat exchanger 2.1 under pressure by means of a pump 6 into the apparatus 3.

[0083] In the first heat exchanger 1.1, for example, heat is transferred to pre-cool the material flow 1 / the refrigerant, and in the second heat exchanger 2.1, pre-cool the material flow 2. In the apparatus 3, the first and second material flows 1, 2 are combined and expand and cool from temperatures T1 of the first material flow 1 and T2 of the second material flow 2 upstream of the apparatus 3 to a lower temperature T of the flow 1 / 2 exiting the apparatus 3.

[0084] In the apparatus 3, a mixture of the material streams 1 and 2 takes place and a direct and / or indirect heat transfer takes place between the first material stream 1 and the second material stream 2 (e.g. injector technology).

[0085] Stream 1 / 2, reduced to a temperature T, is fed from apparatus 3 to vessel 4, in which a phase separation of the two streams 1 and 2 occurs, with the refrigerant of stream 1 preferably settling in the upper region and the coolant of stream 2 settling in the lower region of vessel 4. This allows very low coolant temperatures of down to -20 °C and even lower to -100 °C to be achieved, especially when freezing-point-lowering substances are added to the coolant.

[0086] The refrigerant is released from the container 4 to the environment or partially fed back into the refrigeration circuit A and the material flow 2 / the coolant is then fed back to the device 3 via the heat exchanger 2.1 and the pump 6.

[0087] There is the possibility of indirect discharge of the tank 4 if a heat exchanger 2.2 is integrated into the tank 4, which has a flow VL in direct and a return RLjndirekt and thus realizes a cooling task K.

[0088] Additionally or alternatively, a direct discharge of the coolant 2 from the tank 4 can be realized. For this purpose, the coolant 2 is taken as a flow line VLdirect from the tank 4 and used for a cooling task K, and the coolant 2 is fed back to the tank 4 via a return line VRdirect.

[0089] It is also possible to dispense with the return VRdirekt; in this case, coolant 2 must be supplied to the system by another means, e.g. as described in Figure 2. According to an example not shown, heat transfer / temperature equalization of the two material flows 1, 2 can also be realized in a device upstream of the apparatus 3 (e.g. heat exchanger). Furthermore, the material flows 1, 2 can also be heated and / or cooled in the apparatus 3 by at least one additional heater ZH and / or at least one additional cooler ZK, in particular zone-wise. A continuous or pulsating flow preferably leads through the apparatus 3 and, if required, further flow effects such as turbulence, instability, boundary layer effects, subsonic and supersonic flow can be realized. The supply of the material flow 1 (e.g.Air) into the apparatus 3 preferably takes place at low or high pressures, depending on the process, in particular at 0.01 bar to 2500 bar and possibly in different phases with a temperature of typically -40 °C to 50 °C depending on the recooling and / or intermediate cooling. The second material stream 2 is preferably conveyed into the apparatus at a pressure of 1.1 bar to 2500 bar and also at a temperature of -40 °C to 50 °C. When the two material streams 1 and 2 are combined in the apparatus 3, they come into full and / or partial contact, with the formation of bubbles or droplets, for example. It is also possible for the two material streams to be mixed with direct heat transfer. The following processes are possible when the two material streams 1, 2 are combined in the apparatus 3: - if necessary, dissolution of material stream 1 in material stream 2, - if necessary, downstream heat transfer with an external heat exchanger.The expansion taking place in the apparatus 3 and / or subsequent thereto to produce ice, ice slush / ice particles, snow, cold water or combinations thereof or mixture / suspension of a cooled second material stream 2 is preferably carried out using the following individual effects or combinations thereof: - change in the thermodynamic state of the material stream 1, - if necessary Joule-Thompson effect during the expansion of the refrigerant (material stream 1), if necessary evaporation / sublimation of the material stream 2Furthermore, the phase separation of the material streams takes place in the container / storage unit 4 (preferably at -100 °C to 20 °C) and / or at least partially in the apparatus during the discharge of the gaseous phase (material stream 1) and collection of the ice, ice slush, ice particles, snow, cold water or combinations or mixtures or suspensions thereof (material stream 2). The first material stream 1 preferably comprises a refrigerant in the form of air or other suitable refrigerants such asGas streams from industrial / technical processes, whereby depending on the choice of refrigerant, the pressure when feeding into the apparatus 3 may have to be changed or adjusted accordingly. The material stream 1 further preferably consists of or comprises a refrigerant which is insoluble or only slightly soluble in the coolant of the material stream 2, thereby promoting phase separation in the vessel 4. Mixtures (e.g. water and freezing point lowering substances) or substances which promote phase change (e.g. particles, droplets) can also be used as coolants for operation with storage temperatures well below 0 °C. The suitable pressure can be calculated or determined by testing. The material stream 2 comprises a coolant or consists of a coolant in the form of ice, ice slush / ice particles, snow, cold water or combinations thereof or a mixture / suspension.Material stream 1 (preferably air) is sucked in and compressed from tank 4 and / or from the environment. The pressure of material stream 1 is increased by compressor 5. The recooling of material stream 1 is achieved by heat exchanger 1.1. The following modifications to the refrigerant circuit (material stream 1) can be implemented individually or in various combinations: - single- or multi-stage compression up to a maximum final compression pressure of approximately 2500 bar, - parallel connection of compressors, - with and without intermediate cooling, - if necessary, the use of one or more refrigerant dryers, - if necessary using oil separation. Furthermore, material stream 2 is taken from the lower area of ​​tank 4 in the form of ice, ice slush / ice particles, snow, cold water or combinations thereof or their mixture / suspension and fed to the second heat exchanger 2.1 of the second material stream 2 for the implementation of an optional pre-cooling and from there pumped under pressure back into the apparatus 3 by means of the pump 6. The storage unit (container 4 with storage function) can be discharged directly or indirectly with regard to the second material stream 2. The system according to the invention serves to produce and / or store ice, ice slush / ice particles, snow, cold water or combinations or mixtures / suspensions thereof. The container 4 can be filled at the beginning / before the start of the process with a coolant (preferably water) and a refrigerant (e.g. air), from / in which ice, ice slush / ice particles, snow, cold water or combinations or mixtures / suspensions thereof are formed due to the strong cooling in and / or downstream of the apparatus. It is possible to connect several apparatuses 3 in parallel to increase the cooling capacity or ice production.Furthermore, it is possible to use pumps with higher pressure for the second material stream 2 in order to partially suck in material stream 1, particularly in the area of ​​apparatus 3 (injector effect). This also makes it possible to lower the temperature of material stream 1 or to reduce the temperature reduction for material stream 1 and / or the compression power for material stream 1 and / or to achieve better pre-cooling for material stream 2. Further pre-cooling of material stream 1 is possible internally (in the apparatus) or externally, also using cooling elements external to the apparatus or provided in the apparatus 3. The process and the system can be used as a heat pump system and / or as a combined cooling and heating system. For this purpose, the heat obtained from the recooling of the refrigerant can be used for heating purposes.To recover the compression power of compressor 5 of the first material stream 1, it is possible to integrate an expansion machine into the refrigerant circuit of the first material stream 1. This is preferably done upstream of the device 3. This also allows for partial expansion of the material stream 1, which cools it.

[0090] The expansion machine can, for example, be a displacement machine and / or turbine T, with which in particular a generator G is driven to generate electricity (see Figure 4).

[0091] In the system according to Figure 2, the first material stream 1 is fed in as in Figure 1 at a pressure of up to 2500 bar and at a temperature T 1 of -200 °C to 50 °C. The second material stream 2 in the form of the coolant is fed in an open process under pressure (up to 2500 bar) to the apparatus 3 at a temperature T 2 (max. -40 to 35 °C). After cooling in the apparatus 3 (to temperatures T down to a minimum of -200 °C), stream 1 / 2 is fed to the vessel 4, if necessary via a cyclone (not shown). After the phase separation of the substances 1, 2 in the cyclone or in the vessel, the coolant 1 (preferably air) is released into the environment or at least partially back into the refrigeration circuit A. The coolant of material stream 2 settles at the bottom of the vessel 4. The unloading of the container 4 indicated here to realize the cooling task takes place directly or indirectly, for example as shown in Figure 1.The supply of water, for example, as the coolant 2, can be realized from a tank, a body of water, the pipeline network, or the like. The water / coolant 2 is sucked in via a pump 6 and fed to the device 3 under pressure. A heat exchanger 2.1 can also be provided upstream of the pump 6, if necessary.

[0092] Another variant of the system is shown in Figure 3. This also shows that the material flow 2 from the heat exchanger 2.1 (for optional pre-cooling) is returned to the tank 4 via the device 3. For this purpose, a pump 6 is located between the tank 4 and the heat exchanger 2.1.

[0093] To further reduce the temperature of the coolant 2, a first secondary material stream 2N1 from the container 4 leads via a heat exchanger 2.T and a pump 6.2 at high pressure into the apparatus 3 (to which the first material stream 1 and the second material stream 2 are also fed) and from there, after expansion and cooling, back into the container 4. The coolant 2 returned to the container 4 is significantly cooled, whereby the temperature of the material stream 2 is also reduced to realize the cooling function K.

[0094] In this variant, too, the pressure upstream of the apparatus 3 for the first stream 1 is up to 2500 bar and the temperature T1 is down to at least -200°C, and for the second stream 2, the pressure is up to 2500 bar and the temperature T2 is between -40 and 30°C. Stream 1 / 2 exiting the apparatus 3 also has a temperature T of preferably between -200°C and 20°C.

[0095] The by-product stream 2N1 is fed to apparatus 3 at a pressure of up to 2500 bar and a temperature between -40 °C and 30 °C.

[0096] In Figure 3, the thick dashed line indicates that the coolant 2 can also be supplied from outside, for example from a tank, a body of water, the pipe network or the like.

[0097] Figure 4 shows a variant of a system with an improvement of the simple cold air process by using a multi-stage compression of the refrigerant 1 with intermediate cooling and a resulting extraction of the useful heat, whereby higher pressures and energy-efficient compression can be achieved.

[0098] The refrigerant 1 is conveyed in a material flow 1, here in four stages, via a compressor V1 to V4 and downstream coolers K1 to K4. The coolers K1 to K4 are coupled to a heating system (not shown) via a supply line VL and a return line RL. Heat is extracted from the material flow 1, which has been heated by compression, via at least one or all of the coolers K1 to K4.

[0099] The first material flow 1 is further cooled via one or more additional recoolers - here three recoolers R1, R2, R3 - whereby the extracted heat is released into the environment or used for heating purposes.

[0100] The heat extracted from material stream 1 with at least one cooler K1 to K4 and / or at least one recooler R1 to R3 is intended, for example, for heating purposes in a temperature range of 40°C to 400°C.

[0101] The lower temperature range, from 40 to 90°C, can be used for space heating, for example, while the high temperature range (up to 400°C) can be used for technological processes, for example. In the embodiment shown in Figure 4, coolers K1 to K4 are preferably intended for the higher temperature range, and the recooler R3 for the lower temperature range.

[0102] Furthermore, in the illustrated embodiment, a coupling of at least one cooler K1 to K4 and / or the recooler R3 with at least one further heat pump is possible (not shown).

[0103] The recooler R1 uses the cold exhaust air of material flow 1 from the cyclone 13 and / or the container 4.

[0104] The cold exhaust air from cyclone 13, which serves to cool material stream 1, is fed to the recooler R2.

[0105] The R3 recooler dissipates heat to the environment or provides heating at preferably low temperatures.

[0106] After the recoolers R1, R2, and R3, stream 1 is passed through an expansion machine—here, a turbine T—and / or an expansion device 1.3. As a result, a partial flow of the refrigerant is expanded in the expansion device 1.3, cooling the remaining stream.

[0107] The expansion machine also expands the material flow 2 upstream of the device 3. To generate mechanical power, a generator G is driven by the turbine T.

[0108] Furthermore, a storage 12 for the compressed material flow 1 can be provided, with which an operation optimization and black start capability can be realized.

[0109] The use of a storage device (preferably compressed air storage) 12 to optimize operations is associated with numerous advantages:

[0110] It is possible to charge the storage tank for material flow 1 / compressed air storage tank 12 with no or only little cooling and / or with no or little electricity generation.

[0111] The storage for the material flow / compressed air storage 12 is discharged when the system starts without power (black start capability), when starting / operating with little power, to accelerate the start-up behavior (e.g. provision of control power or when only electricity and / or cooling are to be generated.

[0112] The expansion of the entire material flow 1 preferably takes place in a single or multi-stage manner using the aforementioned expansion machine T (e.g., turbine, positive displacement machine). This can, if necessary, be arranged on a shaft with the compressors and / or a gearbox. Using a generator G driven by the expansion machine T, for example, partial coverage of the compression effort is possible.

[0113] Furthermore, the use of a static expansion device 1.3 (simple pressure loss) as described above is also feasible, for example with a controlled pressure loss and, if required, with a bypass to the turbine / expansion machine T.

[0114] Subsequently, the first material stream 1 is fed to the apparatus 3 after the expansion device 1.3 or the turbine / expansion machine T.

[0115] As in Figure 1, material stream 2 is fed from tank 4 via heat exchanger 2.1 and pump 3 to apparatus 3. Stream 1 / 2 exiting apparatus 3, consisting of material streams 1 and 2, is fed into tank 4, where phase separation occurs. A cyclone 13 is assigned to tank 4 to separate the materials from material streams 1 and 2. The coolant 1 (preferably air) is discharged from cyclone 13 to the environment and / or to the recooler R1 and / or to the precooler 2.1 and / or to the refrigeration circuit A.

[0116] Furthermore, after the expansion machine, here a turbine T, a partial flow (e.g. cold air) of the coolant 1 can be led to a recooler (here R1).

[0117] The coolant 2 located in the container 4 is discharged directly or indirectly to realize the cooling task K - see Figure 1.

[0118] According to an embodiment not shown, the first material stream can also be fed back into the refrigeration circuit and thus into the apparatus after the phase separation in the cyclone or in the container.

[0119] Figures 5 and 6 below show two structural designs of apparatus 3.

[0120] Figure 5 shows a variant of the apparatus 3 with an inner hollow cylindrical / tubular first shell 9, which has an inlet 9.1 and an outlet 9.2 and is provided with a funnel-shaped extension 9.3 toward the outlet 9.2. The first shell 9 is surrounded at a distance by another hollow cylindrical / tubular second shell 10, which is longer here than the first shell 9 and projects beyond the outlet 9.2 of the first shell 9. The first and second shells 9, 10 are arranged centrally with respect to one another along a longitudinal axis A.

[0121] A first annular space 3.1 is formed between the outer circumference of the first jacket 9 and the inner contour of the second jacket 10 and a first chamber 3.2 is formed after the outlet opening 9.2 of the first jacket 9.

[0122] The second jacket 10 points towards the cylindrical area towards the exit

[0123] 10.2 has a funnel-shaped diameter extension 10.3 and at the inlet 10.1 a funnel-shaped diameter reduction 10.4.

[0124] It is possible to feed the first material stream 1 via inlet 9 and the second material stream 2 via inlet 10 (as shown), or vice versa. The two material streams 1, 2, fed under high pressure, come into contact in the area of ​​chamber 3.2 and exit the apparatus 3 at outlet 10.2 as one stream 1 / 2, which is introduced into the container 4 (not shown here). In the apparatus 3, the material streams expand and thus cool significantly. An indirect heat transfer occurs between the material streams in area 3.1 and a direct heat transfer occurs in area 3.2.

[0125] Figure 6 shows a further variant of an apparatus 3 in which the first jacket 9 and the second jacket 10 are designed as in Figure 7, wherein they are additionally surrounded by a third hollow cylindrical jacket 11.

[0126] The third hollow cylindrical shell 11 also has an inlet 11.1 and an outlet

[0127] 11.2 and is provided with a funnel-shaped extension 11.3 in the direction of the outlet 11.2.

[0128] The second shell 11 is surrounded at a distance by the hollow cylindrical / tubular third shell 11, which here is longer than the second shell 10 and thus projects beyond the outlet 10.2 of the second shell 10. The first, second and third shells 9, 10, 11 are also arranged centrally to one another along the longitudinal axis A. A second annular space 3.3 is formed between the outer circumference of the second shell 10 and the inner contour of the third shell 11, and a second chamber 3.4 is formed after the outlet opening 10.2 of the second shell 10. Here, too, it is possible to feed the first material stream 1 via the inlet 9.1 and the second material stream 2 via the inlet 10.1 (as shown), or vice versa. For example, a secondary stream 2N1 can be introduced into the inlet 11.1.

[0129] The two high-pressure material streams 1 and 2 come into contact in the area of ​​chamber 3.2 and enter the second chamber 3.4 at outlet 10.2, where they come into contact with, for example, the material stream of the secondary circuit 2N1. Indirect heat transfer is realized in the annular spaces 3.1 and 3.2, and direct heat transfer is realized in the chambers 3.2 and 3.4.

[0130] In the apparatus 3 and / or after the apparatus 3, all material flows expand, thereby cooling down considerably and are introduced as flow 1 / 2 into the container 4 (not shown here).

[0131] In both variants according to Figures 5 and 6, for example, the respective outer jacket (second jacket 10 or third jacket 11) is provided with an additional heating ZH and / or additional cooling ZK and / or a heat exchanger 3W, which can also be divided into zones.

[0132] The additional heater ZH or the heat exchanger 3W can, for example, prevent an obstruction of the function according to the invention, e.g. an undesirable formation of ice on the surfaces of the apparatus 3.

[0133] According to variants not shown, the streams 1 / 2 exiting the device can also be introduced essentially tangentially into the tank / storage tank 4. This achieves a better separation of the coolant and the refrigerant.

[0134] Alternatively, a different introduction of the material streams into apparatus 3 can be chosen.

[0135] For example, material stream 2 can be introduced via feed 9.1 and material stream 1 via feed 10.1.

[0136] If a jacket in the form of the third jacket 11 is arranged, a secondary material stream 2N1 can then, for example, be introduced into the apparatus 3 via the feed 11.1. The feed of the material streams can also be radial or oblique, according to examples not shown.

[0137] In apparatus 3, the expansion, acceleration and pressure reduction required for the production of ice, ice slush / ice particles, snow, cold water or their combinations or mixtures / suspensions take place.

[0138] When the material streams are combined, reactions between the material streams or, if necessary, a physical dissolution of gases from the first material stream 1 in the liquid from the second material stream 2 can occur.

[0139] A Joule-Thompson effect and possibly a reverse reaction may also occur.

[0140] In the apparatus 3, desired turbulence effects, boundary layer effects and instability effects can occur through the flow guidance and various known design modifications in order to influence the pressure / flow and / or to improve the heat transfer between the material flows or to avoid unfavorable operating conditions.

[0141] Figure 7 shows a system according to the invention in which several apparatuses 3 are arranged parallel to one another. The feeds of material streams 1 and 2 are indicated as a line L. As with the aforementioned variants, the contact of material streams 1 and 2, their expansion, and a direct and / or indirect heat transfer take place in these.

[0142] The devices 3 are arranged in a housing U having an opening U1 and into which an additional air stream (not designated) is drawn in via at least one means M in the form of a compressor and / or fan. The streams 1 / 2 exiting the devices 3 enter a cyclone 13 and are separated therein. Mainly material stream 1 and the additional air exit the upper opening of the cyclone 13, and mainly material stream 2 exits the lower opening.

[0143] To prevent icing, the housing U and / or the cyclone 13 can be provided with a heater (not shown).

[0144] With the method and the system according to the invention, high cooling capacities and high ice productions can be realized, for example for industrial applications, using an ecological refrigerant (such as air) and coolant (ice, ice slush / ice particles, snow, hydrates, cold water or combinations or mixtures / suspensions thereof), whereby temperatures of the coolant from 20 °C to -100 °C can be provided.

[0145] With the system and method according to the invention, very high storage charging capacities (up to, for example, the megawatt range) and very high storage discharging capacities (up to, for example, the megawatt range) are possible. However, depending on the dimensioning, the system can also provide smaller capacities in the kilowatt range.

[0146] Furthermore, district cooling can also be provided via pipelines, for example. Integration into district cooling is also possible.

[0147] It can also be used directly on food products or for sports purposes (e.g. winter sports).

[0148] Due to the relatively simple design of the system, only minimal operating and maintenance effort is required.

[0149] Another advantage is that the system can also be used as a heat pump system and / or as a combined cooling and heating system.

Claims

AMENDED CLAIMS received by the International Bureau on 03 May 2024 (03.05.2024) 1. A method for cooling at least one refrigerant and / or at least one coolant in an open process with a continuous or discontinuous operation for the realization of a cooling task, wherein - at least one first material stream (1) in the form of the refrigerant in the form of compressed air or compressed process gas and - at least one second material stream (2) of the coolant consisting of water and / or water with freezing point lowering substances and / or other coolants and / or their mixtures / suspensions are conveyed by at least one pump under pressure to at least one apparatus (3), wherein upstream of the apparatus (3) - with at least one compressor (5) a compression and conveying of the first material stream (1) with a pressure of 1,1 bar to 2500 bar and the first material flow (1) is guided over at least one cooler / heat exchanger (3) and - with at least one pump (6) a conveyance of the second material flow (2) and a realization of a pressure increase to 1.1 bar to 2500 bar takes place and the refrigerant of the first material flow (1) and the coolant of the second, material flow (2) are brought together in the apparatus (3), - the two material flows (1, 2) relax and cool in and / or upon exiting the apparatus (3), whereby ice, ice slush / ice particles, snow, cold water or other coolants or combinations thereof or mixture / suspension with a low temperature are produced and - the flow (1 / 2) emerging from the apparatus (3) from the material flows (1) and (2) is fed to at least one container / cold storage device (4) with storage function, via which the cooling function takes place, - wherein the discontinuous process for cooling the refrigerant is realized by incorporating at least one storage device in the form of the container / cold storage device (4) for the material flow (1).

2. Method according to claim 1, characterized in that - in and / or upstream of the container (4) a phase separation of the first material stream (1) and the second material flow (2), - the first material flow (1) is discharged from the container / cold storage device (4) to the environment and / or is used for pre-cooling the second material flow and / or cools the compressed first material flow (1) and / or is fed back to the circuit A, - the second material flow (2) is removed from the container / cold storage device (4) to implement at least one cooling task (K) and / or the cooling task (K) is implemented with at least one heat exchanger (2.2) in / on the container / cold storage device (4).

3. Method according to claim 1 or 2, characterized in that the discontinuous process for cooling at least one refrigerant is realized primarily by the integration of at least one storage device (12) for the material flow (1).

4. Method according to one of claims 1 to 3, characterized in that before being fed to the apparatus, the first material stream (1) is recooled by means of at least one recooler, the heat being released to the environment and / or the cold exhaust air from the apparatus (3) or a cyclone (13) associated with the apparatus and / or at least a partial stream being used after expansion of the first material stream (1).

5. Method according to one of the preceding claims, characterized in that the first material stream (1) is passed through at least one expansion machine and / or at least one expansion device before entering the apparatus (3), thereby realizing an expansion and cooling of the first material stream (1).

6. Method according to one of the preceding claims, characterized in that the expansion machine drives at least one generator for power generation and / or the compressor(s) directly or via a gear or other drives consumers.

7. Method according to one of the preceding claims, characterized in that - in the case of a coolant consisting of water, freezing point lowering substances in the form of alcohol, glycols, salts, sugar, organic and inorganic substances or mixtures of some or all of the aforementioned substances are used, and / or - in the case of a coolant in the form of oils, silicones, alcohols, glycols, freezing point lowering substances in the form of solid additives, gaseous additives, phase change materials or mixtures / suspensions of some or all of the aforementioned substances are used, - that oils and / or silicones (organic substances) with or without additives are used as further coolants for low temperatures and / or - that mixtures / suspensions such as water and freezing point lowering substances and / or nucleating substances that promote a phase change, such asparticles and / or droplets, for operation with storage temperatures well below 0 °C.

8. Plant for carrying out the method according to claim 1, for cooling at least one refrigerant and / or at least one coolant in an open process with a continuous or discontinuous operation to realize a cooling task, wherein said plant comprises at least one apparatus (3) which has at least one first feed for at least one first material stream (1) of a refrigerant and at least one second feed for at least one second material stream (2) of a coolant (2) consisting of water and / or water with freezing point lowering substances and / or other coolants, wherein the apparatus (3) has at least one chamber in which the first and second material streams (1, 2) can be combined, expanded and cooled, and that at least one container / cold storage device (4) for realizing the cooling task is connected to the apparatus (3). and that the system is equipped: - with the apparatus (3) for combining and subsequently expanding the first and second material streams (1, 2) to produce ice, ice slush / ice particles, snow, cold water or combinations thereof or mixtures / suspensions, with the container (4) for phase separation of the first and second material streams (1, 2), - with at least one second heat exchanger (2.1) for pre-cooling the second material stream (2), - with at least one pump (6) for conveying the second material stream (2) and for realising a pressure increase to 1.1 bar up to a maximum of 2500 bar upstream of the apparatus (3), - with at least one first heat exchanger (1.1) for realising a recooling of the first material stream (1) to a temperature between -40°C and 50 °C upstream of the apparatus (3), - with at least one compressor (5) for compressing and conveying the first material stream (1) and for realising a pressure of 1.1 bar up to 2500 bar upstream of the apparatus (3).

9. Plant according to claim 8, characterized in that means for phase separation of the first and second material streams (1, 2) are provided upstream of the container and / or in the container / cold storage device (4), and in that the container / cold storage device (4) has at least one outlet for the coolant, and in that the container / cold storage device (4) has at least one further outlet for the coolant (2) and / or at least one heat exchanger (2.2) to realize the cooling task.

10. Plant according to claim 8 or 9, characterized in that at least one secondary material stream (2N1) with / from a coolant leads from the container (4) to the apparatus (3).

11. Plant according to one of the preceding claims 8 to 10, characterized in that a plurality of compressors and coolers are arranged in the coolant supply of the coolant to the apparatus (3), wherein at least one compressor is assigned a heat exchanger / recooler.

12. Plant according to one of the preceding claims 8 to 11, characterized in that a branch to a storage (12) for the intermediate storage of the refrigerant of the material flow (1) is integrated into the material flow 1.

13. Plant according to one of the preceding claims 8 to 12, characterized in that the container (4) with storage function has a tangential or substantially tangential supply for at least one stream (1 / 2) and / or that means for generating a flow with swirl are arranged in the apparatus (3).

14. System according to one of the preceding claims 8 to 13, characterized in that areas of the system which are subject to icing or where there is a risk of icing are provided with an additional heater (ZH) and / or heat exchanger (3W).

15. Plant according to one of the preceding claims 8 to 14, characterized in that the at least one apparatus (3) has at least one inlet for the first material stream (1) and at least one or more inlets for the second material stream (2) and optionally for the secondary circuit (2N1).

16. Use of the method according to claim 1 and the plant according to claim 8 as a heat pump plant and / or as a combined cooling and heating plant and / or as a heat source for at least one further heat pump, wherein heat is extracted from the material flow (1) by at least one cooler and / or at least one recooler and is used in a temperature range of 40°C to 400°C for heating purposes and / or storage charging.

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