Heat storage system and method for operating the same

Abstract

The invention relates to a heat storage system comprising at least one heat source, a tank region (3) having at least two tanks (17) in which a fluid product and / or raw material is stored, and at least one heat sink, and wherein each tank (17) comprises a heat exchange device (19), the at least one heat source, the at least one heat sink and the heat exchange devices (19) are connected in a temperature control circuit (5), and the at least one heat source or the at least one heat sink is a processing device (7). The invention further relates to a method for operating the thermal storage system.

Description

Technical Field

[0001] The present invention relates to a thermal storage system, which includes at least one heat source, a storage tank area having at least two storage tanks, and at least one heat sink. In these storage tanks, fluid products and / or raw materials are stored, and each storage tank includes a heat exchange device. At least one heat source, at least one heat sink, and the heat exchange device are connected in a temperature control loop. Background Art

[0002] Especially during chemical processing, a large amount of thermal energy is generated (e.g., in exothermic reactions) or dissipated. The generated heat must be discharged, for example, by using a heat exchanger for cooling. Especially during exothermic batch processing, a large amount of thermal energy is usually generated discontinuously, and this thermal energy cannot be used in a processing operation that must continuously supply heat to the device, or in a situation where a heat recovery system needs to be continuously operated, or in a situation where there is a time offset between heat generation and heat demand. Currently, in such a case, a thermal storage device can be used, which allows the use of this heat at a time different from the time of heat generation. Thermal energy can be stored, for example, by heating a storage medium or by changing the state of matter (latent heat) of a material or both.

[0003] For example, such a thermal storage system using a latent heat storage medium is disclosed in US-A 2011 / 0146940. Currently, such a thermal storage system is used, for example, to store heat generated by solar energy to produce hot water when there is not enough solar energy available.

[0004] Currently, the heat generated during industrial processing is usually dissipated and optionally used, for example, to generate steam or in a heat integration system, where, for example, the heat generated during processing is used to preheat a feed stream. If heat is to be stored, a separate thermal storage device is usually provided. The disadvantage of using a single thermal storage unit is that it is difficult to store heat at different temperature levels. This can be avoided, for example, by partitioning or using stratified storage, which in turn reduces the capacity of these different temperature levels. If only one temperature level is used, a large storage capacity can be achieved, but a trade-off is required between using a high storage temperature level (resulting in a loss of most of the thermal energy output of the facility) and a low storage temperature level (causing a higher amount of energy to be stored but resulting in an exergy loss). Providing a large-capacity thermal storage device at different temperature levels usually leads to the equipment expenses necessary for setting up the corresponding thermal storage device. Summary of the Invention

[0005] Therefore, the object of the present invention is to provide a thermal storage system that does not have the disadvantages of current thermal storage devices.

[0006] This object can be achieved by a thermal storage system comprising at least one heat source, a storage tank area having at least two storage tanks, and at least one heat sink, wherein a fluid product and / or raw material is stored in these storage tanks, and each storage tank comprises a heat exchange device, wherein the at least one heat source, the at least one heat sink, and these heat exchange devices are connected in a temperature control loop, and wherein at least one heat source or at least one heat sink is a processing device.

[0007] In particular, in the chemical industry, fluid products or feed materials are stored in storage tanks, which are usually located in a so-called storage tank area, i.e., the area of the site where these storage tanks are located. Since different fluids can be stored in the storage tanks, depending on the fluid stored in the storage tank, the storage tanks can generally also have different temperatures. Generally speaking, the temperature in each storage tank is set such that the fluid maintains its phase (e.g., liquid phase or gas phase) and is stored at a predetermined viscosity to achieve the best conditions for the fluid to be used in a processing process or for further transportation.

[0008] The temperature of the fluid in the storage tank is generally in the range from -200 °C to 800 °C, preferably in the range from -100 °C to 250 °C, more preferably in the range from 0 °C to 200 °C, and particularly in the range from 50 °C to 100 °C. The fluid can be any liquid or gas that can be stored in a storage tank, preferably a liquid.

[0009] In order to use the fluid in the storage tank as a thermal storage device, the fluid can be further heated or cooled to a temperature different from the normal storage temperature, as long as the temperature to which the fluid is heated or cooled is within a certain range, in which the properties of the fluid remain unchanged, so as to further use the fluid and without having an undesirable effect on the fluid (e.g., due to an undesirable chemical reaction).

[0010] Since the fluid in the storage tanks of the storage tank area usually needs to be heated or cooled and a heating or cooling system is used for the storage tank area, the thermal storage system of the present invention has the following advantages that there is no need to use a separate heating or cooling system, but rather to use the heat generated in the processing process carried out in an industrial site to heat the storage tanks in the storage tank area and / or to cool the storage tanks in the hot storage tank area by using heat in such a process. For this purpose, the thermal storage system of the present invention is particularly suitable for industrial sites that combine a production facility with at least one storage tank area.

[0011] Using the storage tanks in the storage tank area as thermal storage devices has the additional advantage that due to the usually large size of such storage tanks, a large amount of fluid is stored in the storage tanks that can be used as a thermal storage medium. Usually, the storage tanks in the storage tank area have a volume of up to 5000 m 3 and generally in the range from 0.1 m 3 to 2500 m 3within the range, more preferably in the range from 20 m 3 to 1000 m 3 and particularly in the range from 50 m 3 to 500 m 3 within the range.

[0012] To use different temperature levels, it is further preferred that the industrial site includes a plurality of production facilities in which production processes are carried out and different products stored at different temperatures are produced. In particular, for use with different production facilities or for storing different fluids, it is preferred that the fluid products and / or raw materials in at least two storage tanks in the storage tank area are stored at different temperatures.

[0013] To transfer heat to or from the fluid in the storage tank to the heat transfer medium, at least two heat exchange devices can be connected in series. Alternatively, at least two heat exchange devices can be connected in parallel. Thus, it is possible that all heat exchange devices are connected in series or all heat exchange devices are connected in parallel. Further, it is also possible that at least two heat exchange devices are connected in series and at least two heat exchange devices are connected in parallel.

[0014] Connecting the heat exchange devices in parallel has the advantage that each heat exchange device can be operated individually if the flow of the heat transfer medium through the heat exchange device can be stopped, for example, by positioning a valve upstream or downstream of each heat exchange device.

[0015] In particular, if the fluids in different storage tanks are stored at the same temperature, it is preferred that these storage tanks are connected in parallel because in this case the heat transfer medium can be fed into the corresponding heat exchange devices at the same temperature. On the other hand, to store fluids at different temperatures in different storage tanks connected in parallel, the flow rate of the heat transfer medium through the heat exchange device can be set, for example, by using a control valve.

[0016] If at least two heat exchange devices are connected in series, the heat transfer medium flows continuously through the heat exchange devices. When the heat transfer medium transfers heat to the fluid in each storage tank, the heat transfer medium becomes colder in each heat exchange device, and thus the inlet temperature of the heat transfer medium entering the heat exchange device decreases. Therefore, it is preferred to connect the storage tanks operating at different temperatures in series such that during heat generation in the processing equipment, heat is transferred to the fluid in the at least two storage tanks connected in series, the temperature of the storage tank having a heat exchange device connected downstream of another heat exchange device being lower than the temperature of the storage tank having a heat exchange device connected upstream, and during heat discharge from the storage tank area, heat is transferred from the at least two storage tanks connected in series to the heat transfer medium, wherein the temperature of the storage tank having a heat exchange device connected downstream of another heat exchange device is higher than the temperature of the storage tank having a heat exchange device connected upstream.

[0017] To heat or cool the fluid in the storage tank having heat exchange devices connected in series individually, it is further preferred that the temperature control loop includes a bypass line such that each of the heat exchange devices connected in series can be bypassed. To operate the heat exchange devices connected in series individually, it is further preferred that each bypass line includes a valve through which the bypass line can be closed. For operating an individual heat exchange device, the valve is preferably located upstream and / or downstream of each heat exchange device. By closing the valve upstream or downstream of the heat exchange device, the flow of the heat transfer medium stops and thus the heat exchange with the fluid in the storage tank stops. If it is intended that all of the heat transfer medium flows through the heat exchange device, the valve in the bypass line is closed while the valve upstream and / or downstream of the heat exchange device is opened. On the other hand, if it is intended that only a part of the heat transfer medium flows through the heat exchange device and a part flows through the bypass line, the valve in the corresponding bypass line and the valve upstream and / or downstream of the heat exchange device are opened. By setting the opening cross-section of the valve, the flow rate of the heat transfer medium through the heat exchange device and through the bypass line can be set.

[0018] Since a storage tank area is generally part of a chemical site, the processing equipment connected to the temperature control loop is equipment used in a chemical process. Such equipment can be operated continuously or discontinuously and is, for example, a chemical reactor, evaporator, cooler, heater, membrane module, dryer, condenser, column (such as a distillation column) or any other equipment used in a chemical process and known to a person skilled in the art, as well as the corresponding heat exchangers for heating or cooling components in a chemical process. Typically, in this context, a chemical reactor and a condenser in which an exothermic reaction takes place are heat sources, and a chemical reactor, evaporator, heat pump, steam generator, steam drum or distillation column in which an endothermic reaction takes place are heat sinks. However, particularly if an evaporator or a distillation column is connected to the temperature control loop, it is preferred that the evaporation temperature or the distillation temperature is lower than the storage temperature of the fluid in the storage tank of the storage tank area from which heat is transferred. If the evaporation or distillation temperature or the temperature at which an endothermic chemical reaction takes place is higher than the storage temperature of the fluid in the storage tank of the storage tank area, an additional heating step is required. In the additional heating step, heat can be transferred from the temperature control loop to an expansion fluid, which is then compressed, and by compression, the pressure and thus the temperature of the fluid increase, and the heat of the compressed fluid is transferred to the components in the evaporator, distillation column or reactor, and subsequently the fluid expands, thereby cooling to a temperature below the temperature of the heat transfer medium of the temperature control loop. Alternatively, a heating device such as electric heating, steam heating, further heat integration by using a heat source with a higher temperature, or a burner can also be used to provide heat in the additional heating step.

[0019] Particularly preferably, the processing equipment is a chemical reactor.

[0020] Depending on the layout of the production facility and the storage tank area in the chemical site, it is possible that each production facility is connected to one storage tank area or at least two production facilities are connected to one storage tank area. If more than one production facility is connected to a storage tank area, it is preferred that the production facilities are connected in parallel to the temperature control loop and the storage tank area is connected in series to the production facilities. Particularly, if the fluids in the storage tanks of the storage tank area are stored at different temperatures and the production facilities also operate at different temperatures, it is preferred that each production facility is connected to a part of the storage tank area that contains the storage tanks of the fluid having a temperature matching the temperature of the production facility. However, even if the production facilities operate within a corresponding temperature range or all storage tanks have the same temperature, it is preferred that the temperature control loop connects the production facilities to a part of the storage tanks of the storage tank area.

[0021] If the heat generated during the processing in the production facility is more than the heat that can be stored in the storage tank, or if additional heat is required, it is preferred that at least one additional heat exchange device for heat supply or heat dissipation be connected to the temperature control circuit. In the additional heat exchange device, the heat can be transferred to a cooling medium for additional cooling or to a heating medium for additional heating of the processing carried out in the processing equipment.

[0022] In addition to the heat exchange device connected to the temperature control circuit, it may be preferred that each storage tank includes a second heat exchange device. The second heat exchange device can be a heat exchanger that can operate independently of the temperature control circuit or a heat exchanger that is also connected to the temperature control circuit.

[0023] Using a second heat exchange device that can operate independently of the temperature control circuit allows for, for example, additional heating or cooling of the fluid in the storage tank. Such a second heat exchange device may be required, for example, if the heat generated in the processing equipment is not sufficient to heat the fluid in the storage tanks in the storage tank area. Here, "not sufficient" means that the amount of heat and / or the temperature difference is not high enough. On the other hand, if it is necessary to cool the fluid in the storage tank at a specific moment, for example, to empty or fill the storage tank, and the heat sink in the temperature control circuit is not sufficient to dissipate this additional heat, or there is no additional heat sink in the temperature control circuit, such a second heat exchange device can also be used. If the heat consumed in the processing equipment is not sufficient to cool the fluid in the storage tank or the fluid must be heated at a specific moment, and there is no heat source or the heat provided by the heat source is not sufficient in the temperature control circuit, the second heat exchange device for heating described here can also be applied to cooling.

[0024] If the second heat exchange device is connected to the temperature control circuit, it is preferred that the heat exchange device is used for heating and the second heat exchange device is used for cooling, or vice versa. In this case, the heat exchange device and the second heat exchange device are each connected in series, and further preferably, in the temperature control circuit, the additional heat exchange device is located between the last heat exchange device in the corresponding series-connected heat exchange device and the first second heat exchange device.

[0025] During the operation of the heat storage system, in order to heat the fluid in at least one storage tank in the storage tank area, the heat released in the processing equipment is transferred to the heat transfer medium in the temperature control circuit, and the heat transfer medium flows through the temperature control circuit to the heat exchange device of the storage tank where the fluid will be heated. Or, in order to heat the processing equipment, the heat is transferred from the fluid in at least one storage tank in the storage tank area to the heat transfer medium in the temperature control circuit, and the heat transfer medium flows to the processing equipment and transfers the heat to the processing equipment.

[0026] To transfer the heat released in a processing apparatus to a heat transfer medium in a temperature control circuit or to transfer heat from the heat transfer medium in the temperature control circuit to the processing apparatus, any suitable heat exchange device for indirect heat exchange can be used. Such a heat exchange device is, for example, a double jacket, a coil arranged in the processing apparatus (through which the heat transfer medium flows), or a heat exchanger arranged in a fluid circuit of the processing apparatus (for example, a circuit in which fluid flows out of the processing apparatus, through the heat exchanger to be heated or cooled, and then back to the processing apparatus). In this case, heat is transferred from the circulating fluid to the heat transfer medium of the temperature control circuit in the heat exchanger, or vice versa.

[0027] The processing apparatus can be operated continuously or batchwise. If the processing apparatus is operated batchwise, heat can only be transferred during the operation. For example, if the processing apparatus is a batch-operated reactor, heat can be transferred during the reaction in the reactor. If in this case it is desired to continuously heat the fluid in a storage tank in a storage tank area, a second heat exchange device needs to be provided, through which heat can be transferred during periods when no heat is generated in the processing apparatus. As an alternative, if enough heat is generated during the periods of operation of the processing apparatus to continuously heat the fluid in the storage tank in the storage tank area, an additional heat storage device can be provided, such as the fluid in another storage tank in the storage tank area, which can be heated to a temperature higher than the normal storage temperature, or an additional heat storage device can be provided, such as latent heat storage (such as a phase change material). In this case, during the operation of the processing apparatus, a part of the heat transfer medium is used to heat the fluid in the storage tank, and a part of the heat transfer medium is used to transfer heat to the additional heat storage device. For this purpose, the additional heat storage device can be connected in parallel to the heat exchange device or in series to the heat exchange device, where in order to supply enough heat during the non-operation periods of the processing apparatus, the additional heat storage device must be connected upstream of the heat exchange device of the storage tank in which the fluid must be continuously heated. To continuously heat the fluid in this storage tank, during the non-operation of the processing apparatus, by generating a flow of the heat transfer medium in the temperature control circuit, first flowing through the additional heat storage device (where the heat transfer medium absorbs heat), and then flowing through the heat exchange device (where the fluid must be continuously heated, where the heat transfer medium dissipates heat to the fluid in the storage tank), heat is transferred from the additional heat storage device to the heat exchange device of the storage tank in which the fluid will be continuously heated.

[0028] To avoid heat loss, it is further preferred that, when emptying a storage tank in a storage tank area, during the emptying of one storage tank in the storage tank area, heat is transferred from the fluid in this storage tank to the heat transfer medium in the heat exchange device, and this heat transfer medium flows to the heat exchange device of another storage tank and transfers heat to the fluid in this other storage tank. This is possible especially when the fluid in the storage tank can be withdrawn and conveyed or further processed at a lower temperature.

[0029] On the other hand, if the fluid withdrawn from the storage tank has to be heated during the emptying of the storage tank, it is also possible that during the emptying of one storage tank in the storage tank area, heat is transferred from the fluid of at least one non-emptied storage tank to the heat transfer medium, which flows to the emptied storage tank and transfers the heat to the fluid withdrawn from the storage tank to be emptied.

[0030] In order to heat or cool the fluid in the storage tank during the emptying of the storage tank, the heat transfer medium can be circulated through the entire temperature control loop, or by providing a bypass around the processing equipment, the heat transfer medium is circulated only through the storage tanks in the storage tank area. In order to heat the storage tanks in the storage tank area and cool another storage tank in the storage tank area at the same time, it is particularly preferred that a heat exchange device and a second heat exchange device are provided in each storage tank. If these heat exchange devices are connected in series, the heat exchange device is used to heat the fluid in the storage tank and the second heat exchange device is used to cool the fluid in the storage tank. In this case, during the heating of the fluid in the storage tank, the second heat exchange device is bypassed, and during the cooling, the heat exchange device is bypassed.

[0031] If the heat exchange device is connected in parallel to the temperature control loop, it is preferred that the heat exchange device is connected such that the flow direction of the heat transfer medium can be reversed. In this case, if the heat transfer medium flows in the first direction, heat is transferred from the heat transfer medium to the fluid in the storage tank, and if the heat transfer medium flows in the opposite direction, heat is transferred from the fluid in the storage tank to the heat transfer medium. However, in order to provide a heat storage system that allows one storage tank to be heated and another storage tank to be cooled simultaneously, it is preferred that the heat exchange device and the second heat exchange device are arranged in series.

[0032] The first and second heat exchange devices can be any heat exchange devices that allow indirect heat exchange with the contents in the corresponding storage tank. Suitable heat exchange devices are, for example, heat exchangers, heat coils in the corresponding storage tank, and double jackets.

[0033] In particular, if it is not necessary to continuously heat or cool the fluid in the storage tank, the thermal storage system can be operated such that during heat generation in the processing equipment, heat is transferred to the fluid in at least one of the storage tanks in the storage tank area and the heat exchange device of at least one of the storage tanks in the storage tank area is bypassed until the fluid has a predetermined temperature. After the fluid has reached the predetermined temperature, the heat exchange device of each storage tank in which the fluid has been heated is bypassed, and the heat exchange device of at least one of the bypassed storage tanks is opened to heat the fluid in the storage tank until the predetermined temperature is reached. This operation is particularly preferred if the heat exchange devices are connected in series and the temperatures of the fluids in different storage tanks are the same. As an alternative to operating only one heat exchange device, more than one of the serially connected heat exchange devices can also be operated as long as the temperature of the heat transfer medium is higher than the temperature of the fluid in the storage tank (if the fluid is to be heated) or as long as the temperature of the heat transfer medium is lower than the temperature of the fluid in the storage tank (if the fluid is to be cooled). In this case, the heat exchange device is bypassed when the fluid in the storage tank has reached the predetermined temperature. Due to bypassing the heat exchange device, the heat transfer medium flowing through the last operated heat exchange device has a higher temperature when leaving the heat exchange device, so that the next heat exchange device can be set to enter operation. To avoid unintentional cooling of the fluid in the storage tank, it is particularly preferred to bypass the heat exchange devices of those storage tanks in which the fluid has a temperature higher than the temperature of the heat transfer medium. This also applies to unintentional heating if the temperature of the fluid in the storage tank is lower than the temperature of the heat transfer medium. Description of the Drawings

[0034] Embodiments of the present invention are shown in the drawings and described in more detail in the following description.

[0035] In these figures:

[0036] Figure 1 A temperature control circuit and a storage tank area of a method according to the prior art are shown;

[0037] Figure 2 A thermal storage system with heat exchange devices connected in parallel in a first embodiment is shown;

[0038] Figure 3 A thermal storage system with heat exchange devices connected in parallel in a second embodiment is shown;

[0039] Figure 4 A thermal storage system with heat exchange devices connected in parallel in a third embodiment is shown;

[0040] Figure 5 A thermal storage system with heat exchange devices connected in series in a first embodiment is shown;

[0041] Figure 6 Shows a heat storage system with heat exchange devices connected in series in the second embodiment;

[0042] Figure 7 Shows a heat storage system having a heat exchange device and a second heat exchange device, the second heat exchange device not being connected to the temperature control circuit;

[0043] Figure 8 Shows a heat storage system having a heat exchange device and a second heat exchange device, the second heat exchange device being connected to the temperature control circuit. Detailed Description

[0044] Figure 1 Schematically shows a temperature control circuit and a storage tank area according to the prior art.

[0045] Generally, in an industrial site (e.g., a chemical site), the processing facility 1 (e.g., a production facility) and the storage tank area 3 are separate. In this case, the processing facility 1 includes a first temperature control circuit 5a, and the storage tank area 3 includes a second temperature control circuit 5b.

[0046] The processing facility 1 includes at least one processing device 7. If the processing device 7 has to be heated for a processing operation (e.g., an endothermic reaction or evaporation), the processing device 7 is a heat sink. On the other hand, if the processing device 7 has to be cooled for a processing operation (e.g., an exothermic reaction or condensation), the processing device 7 is a heat source.

[0047] To supply heat to the processing device 7 when the processing device 7 is a heat sink, or to remove heat from the processing device 7 when the processing device 7 is a heat source, the processing device includes a heat exchange device 9, such as the double jacket shown here, which is connected to the first temperature control circuit 5a. For heating or cooling, a heat transfer medium flows through the heat exchange device 9. Besides the double jacket, the heat exchange device can be any device known to those skilled in the art through which heat from the heat transfer medium can be transferred to or from the contents in the processing device 7, besides the double jacket, for example, a heat coil or a heat exchanger in an external fluid circuit through which a processing fluid flows for heating or cooling.

[0048] To remove heat from the processing operation to cool the processing device 7, or to supply heat to the processing device 7, it is necessary to remove heat from or supply heat to the temperature control circuit 5a. For this purpose, a heat exchanger 11 is connected to the temperature control circuit. If the processing device 7 is a heat source, the heat exchanger 11 can be, for example, a central cooling unit.

[0049] In addition to the processing device 7, the temperature control circuit 5a may include an additional heat source 13. The heat generated in the additional heat source 13 is also dissipated in the heat exchanger 11. If the processing device 7 is a heat sink, the temperature control circuit 5a may include an additional heat sink instead of the additional heat source 13.

[0050] To operate the first temperature control circuit 5a, a pump 15 is included, through which the flow of the heat transfer medium through the first temperature control circuit 5a is generated.

[0051] The storage tank area 3 generally includes at least two storage tanks 17. To control the temperature in the storage tanks 17 of the storage tank area 3, each storage tank 17 is equipped with a heat exchange device 19. Generally, the heat exchange devices 19 are connected in parallel to the second temperature control circuit 5b, as shown herein. However, alternatively, the heat exchange devices 19 may also be connected in series. If the fluid stored in the storage tanks 17 in the storage tank area must be heated, the second temperature control circuit 5b includes a heat exchanger 21, in which the heat transfer medium of the second temperature control circuit 5b is heated. On the other hand, if the fluid stored in the storage tanks 17 must be cooled, the heat transfer medium of the second temperature control circuit 5b is cooled in the heat exchanger 21, and thus the heat is dissipated. To generate the flow of the heat transfer medium in the second temperature control circuit 5b, the second temperature control circuit 5b includes a second pump 23.

[0052] To separately heat or cool the fluid in the storage tanks 17, preferably, the flow of the heat transfer medium through each of the heat exchange devices 19 can be controlled. For this purpose, generally, valves 25 are located upstream or downstream of the heat exchange devices 19, through which the flow rate can be set or the flow can be stopped.

[0053] Figure 2 A heat storage system according to the present invention with heat exchange devices connected in parallel in a first embodiment is shown.

[0054] Compared with Figure 1 the prior art shown, in the heat storage system according to the present invention, the first temperature control circuit 5a and the second temperature control circuit 5b are combined into one temperature control circuit 5. For this purpose, the temperature control circuit 5 includes a first connecting pipeline 27a and a second connecting pipeline 27b, through which the temperature control circuit 5 is formed, in which the additional heat source 13, the heat exchanger 11, and the heat exchange devices 19 are all connected in parallel.

[0055] Due to the valves 29 in each of the connecting pipelines 27a, 27b and the bypass pipeline 31, the processing facility 1 and the storage tank area 3 can be operated separately by closing the valves 29. In this case, the temperature control circuit 5 is divided into separate temperature control circuits for the processing facility 1 and the storage tank area 3, as Figure 1 shown.

[0056] In the case of the combined temperature control circuit 5, if the heat supplied by the processing equipment is not sufficient to heat the fluid in the storage tank 17 in the storage tank area, the heat exchanger 21 can be used to supply additional heat.

[0057] Figure 3 A second embodiment of a heat storage system with a heat exchange device connected in parallel is shown.

[0058] Unlike Figure 2 the heat storage system of, the temperature control circuit 5 does not include an additional heat source 13 and the bypass line 31 only bypasses the heat exchanger 11, but since the bypass line is connected to the line connecting the processing equipment 7 and the heat exchange device 19 through the connecting line 33, for example, when the processing facility 1 is shut down or the processing equipment 7 is not operating, only the storage tank area 3 can operate alone, but it is impossible to operate the temperature circuits of the processing facility 1 and the storage tank area 3 separately at the same time.

[0059] Figure 4 A third embodiment of a heat storage system with a heat exchange device connected in parallel is shown in

[0060] In Figure 4 the embodiment shown, the temperature control circuit 5 includes a low-temperature heat sink 35 and a high-temperature heat sink 37. Each heat exchange device 19 is connected to the low-temperature heat sink 35 through a line 41 and to the high-temperature heat sink 37 through a line 34. Downstream of the low-temperature heat sink 35 and the high-temperature heat sink 37, the lines through which the heat transfer medium flows are combined, and a third pump 39 is provided in the combined line to generate the flow of the heat transfer medium.

[0061] In the low-temperature heat sink 35 and the high-temperature heat sink 37, heat can be dissipated, for example, when the heat generated by the processing equipment 7 is more than the heat required to set the temperature in the storage tank 17.

[0062] In this context, a low-temperature heat sink refers to a heat sink that operates below the lowest temperature at which heat is stored in the storage tank area. This does not necessarily define the lowest temperature at which the liquid is stored in the storage tank area, but it determines the lowest temperature level at which heat can be utilized. A high-temperature heat sink refers to a heat sink that operates at a temperature higher than the low-temperature heat sink. Storing heat at different energy levels allows the heat stored in the heat sink at different temperatures to be utilized, which minimizes exergy losses. Particularly preferred heat sinks are steam generators, heat pumps, and heat engines.

[0063] Figure 5 A heat storage system with a heat exchange device connected in series in the first embodiment is shown.

[0064] Figure 5 The embodiment shown is different from Figure 3 the embodiment shown in the connection of the heat exchange device 19 to the temperature control circuit 5.Figure 3 the heat exchange devices 19 in the illustrated embodiment are connected in parallel, while Figure 5 the heat exchange devices 19 in the embodiment of

[0065] By connecting the heat exchange devices 19 in series, in each heat exchange device 19 through which the heat transfer medium flows, heat is supplied to the fluid in the storage tank 17. Due to the heat supplied to the fluid in the storage tank 17, the heat transfer medium cools down. Therefore, if the fluids in different storage tanks are stored at different temperatures, connecting the heat exchange devices 19 in series is particularly suitable, where the heat exchange devices 19 are connected in such a way that the heat exchange device 19 connected downstream of another heat exchange device 19 is heating the fluid in the storage tank 19 at a lower temperature, i.e., the heat exchange device 19 of the storage tank 17 having the hottest fluid is the first in series, and the heat exchange device 19 of the storage tank 17 having the coldest fluid is the last in series.

[0066] In Figure 5 the illustrated embodiment, each heat exchange device 19 can be bypassed through the bypass line 45. This has the advantage that the storage tank 17 can be heated individually, and the heat transfer fluid only flows through those heat exchange devices 19 in the storage tank 17 that contain the fluid to be heated.

[0067] In Figure 5 the embodiment, heat is supplied to the fluid in the storage tank 17 of the storage tank area 3. Since the temperature in the storage tank 17 decreases from the first storage tank to the last storage tank, it is reasonable to use the heat from one storage tank when discharging heat. Figure 6 An embodiment is shown in which heat is allowed to be transferred from the processing device 7 to the storage tank 17 of the storage tank area 3 and from the storage tank 17 of the storage tank area 3 to the processing device 7.

[0068] To supply heat from the processing device 7 to the heat exchange device 19, the valve 47 in the supply line 47 and the valve 48 in the return line are opened, and the first countercurrent line 49, the second countercurrent line 51, and the third countercurrent line 53 are closed. Any suitable valve can be used to close and open the pipeline. In this case, the flow of the heat transfer medium corresponds to Figure 5 the flow of the embodiment of

[0069] To supply heat from the fluid in the storage tank 17 to the processing device 7, the flow must be reversed. For this purpose, the valve 47 in the supply line and the valve 48 in the return line are closed, and the countercurrent lines 49, 51, 53 are opened. The fluid flows from the heat exchange device 19 in the opposite direction (opposite to the arrow direction) through the first countercurrent line 49 to the pump 15 and then through the heat exchange device 9. The heat transfer medium flows from the heat exchange device 9 through the second countercurrent line 51, through the second pump 23 and the third countercurrent line 53 and returns to the heat exchange device 19.

[0070] If the heat stored in the storage tank 17 is insufficient or additional heat needs to be supplied to the processing device 7, for example for starting an active process, the additional heat exchanger 55 can be connected upstream of the processing device 7 to the temperature control circuit 5.

[0071] Figure 7 A third embodiment of a heat storage system with heat exchange devices connected in series is shown.

[0072] Unlike Figure 5 the embodiment shown, in Figure 7 the embodiment, the heat transfer medium always flows through all the heat exchange devices 19 because there is no bypass line 45 that allows bypassing the heat exchange devices 19. On the other hand, the additional line 57 allows for the separate operation of the processing facility 1 and the storage tank area 3.

[0073] To provide additional heat when the heat generated in the processing device 7 is insufficient to heat the fluid in the storage tank 17, each storage tank is equipped with a second heat exchange device 59. Alternatively or additionally, the second heat exchange device 59 can be used to discharge heat from the fluid in the storage tank 17.

[0074] Figure 8 A fourth embodiment of a heat storage system with heat exchange devices connected in series is shown.

[0075] Unlike Figure 5 the embodiment shown, in Figure 8 the embodiment, each storage tank 17 in the storage tank area 3 includes a second heat exchange device 59. Here, the second heat exchange device 59 is connected to the temperature control circuit 5.

[0076] In the embodiment shown here, the heat exchange device 19 is used to heat the fluid in the storage tank 17, and the second heat exchange device 59 is used for cooling. Similar to the heat exchange device 19, the second heat exchange device 59 can also be bypassed through the bypass line 45. This allows for the separate operation of the heat exchange device 19 and the second heat exchange device 59, such that each storage tank can be heated or cooled separately, and in particular, one storage tank 17 can be heated while another storage tank 17 is cooled simultaneously.

[0077] To dissipate the heat from the storage tank area, the temperature control circuit 5 includes a cooling line 61 with a heat sink 63. To dissipate the heat, the valve 65 upstream of the second pump 23 is operated such that at least a part or all of the heat transfer medium flows through the heat sink 63. The heat sink 63 is, for example, a steam generator, a heat pump, a heat engine, or different processing processes that consume heat.

[0078] The heat transfer medium can flow from the heat sink 63 to the second pump 23, and then to the processing device 7 to absorb heat.

[0079] By closing the corresponding valves in the temperature control circuit 5, the heat transfer medium can also be circulated only through at least one of the second heat exchange device 59 and the heat sink 63 to cool the fluid in the corresponding storage tank. If heat dissipation is not required, the temperature control circuit 5 can be operated as Figure 5 shown.

Claims

1. A heat storage system comprising at least one heat source, a tank area (3) having at least two tanks (17), and at least one heat sink, wherein: Fluid products and / or raw materials are stored in these tanks (17), and each tank (17) includes a heat exchange device (19), wherein the at least one heat source, the at least one heat sink, and the heat exchange devices (19) are connected in a temperature control loop (5), wherein at least one heat source or at least one heat sink is a processing device (7).

2. The thermal storage system according to claim 1, wherein: The fluid products and / or raw materials in the at least two tanks (17) of the tank area (3) are stored at different temperatures.

3. The thermal storage system according to claim 1 or 2, wherein: At least two heat exchange devices (19) are connected in parallel.

4. The thermal storage system according to any one of claims 1 to 3, wherein: At least two heat exchange devices (19) are connected in series.

5. The thermal storage system according to claim 4, wherein: The temperature control circuit (5) comprises a bypass line (45) making it possible to bypass each of the heat exchange devices (19) connected in series.

6. The thermal storage system according to any one of claims 1 to 5, wherein: The processing equipment (7) is a chemical reactor.

7. The thermal storage system according to any one of claims 1 to 6, wherein: The temperature control circuit (5) comprises at least one additional heat exchanger (21) for heat supply or heat dissipation.

8. The thermal storage system according to any one of claims 1 to 7, wherein: Each storage tank (17) comprises a second heat exchange device (59).

9. The thermal storage system according to any one of claims 1 to 8, wherein: The second heat exchange devices (59) are connected to the temperature control circuit (5).

10. A method for operating a thermal storage system according to any one of claims 1 to 9, wherein: In order to heat the fluid in at least one tank (17) of the tank area (3), the heat released in the processing equipment (7) is transferred to the heat transfer medium in the temperature control circuit (5), and the heat transfer medium flows through the temperature control circuit (5) to reach the heat exchange device (19) of the tank (17) in which the fluid is to be heated, or wherein, in order to heat the processing equipment (7), heat is transferred from the fluid in at least one tank (17) of the tank area (3) to the heat transfer medium in the temperature control circuit (5), and the heat transfer medium flows to the processing equipment (7) and transfers the heat to the processing equipment (7).

11. The method according to claim 10, wherein: During the emptying of a tank (17) of the tank area (3), heat is transferred from the fluid in the tank (17) to the heat transfer medium in the heat exchange device (19), and the heat transfer medium flows to the heat exchange device (19) of another tank (17) and transfers heat to the fluid in the other tank (17).

12. The method according to claim 10, wherein: During the emptying of a tank (17) of the tank zone (3), heat is transferred from the fluid of at least one tank (17) that has not been emptied to the heat transfer medium, which flows to the emptied tank (17) and transfers heat to the fluid drawn from the tank (17) to be emptied.

13. The method according to any one of claims 10 to 12, wherein: During heat generation in the processing equipment (7), heat is transferred to the fluid in at least one tank (17) in the tank area (3), and the heat exchange device (19) of at least one tank (17) in the tank area (3) is bypassed until the fluid has a predetermined temperature. After the fluid has reached the predetermined temperature, the heat exchange device (19) of each tank (17) in which the fluid has been heated is bypassed, and the heat exchange device (19) of at least one bypassed tank (17) is opened to heat the fluid in the tank (17) until the predetermined temperature is reached.

14. The method according to any one of claims 10 to 12, wherein: During heat generation in the processing device (7), heat is transferred to fluid in at least two tanks (17) connected in series, wherein the temperature of the tank (17) having a heat exchange device (19) connected downstream of another heat exchange device (19) is lower than the temperature of the tank (17) having a heat exchange device (19) connected upstream.

15. The method according to any one of claims 10 to 14, wherein: During heat discharge from the tank area (3), heat is transferred from at least two tanks (17) connected in series to the heat transfer medium, wherein the temperature of the tank (17) having a heat exchange device (19; 59) connected downstream of another heat exchange device (19; 59) is higher than the temperature of the tank (17) having a heat exchange device connected upstream.

Images