Device for the production and use of a heat transfer fluid in a closed circuit
The device with a dual-compartment buffer tank and controllable regeneration unit optimizes heat transfer fluid management by forecasting energy needs, addressing inefficiencies in existing systems and reducing energy consumption.
Patent Information
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- SAVOIE PROCESS
- Filing Date
- 2024-02-15
- Publication Date
- 2026-05-22
AI Technical Summary
Existing systems for heat transfer fluid management in buffer tanks do not effectively account for energy requirements, leading to inefficient energy consumption and oversized installations.
A device with a buffer tank comprising two compartments separated by a flexible membrane, a fluid consumption circuit, a regeneration fluid circuit, and a controllable heat transfer fluid regeneration unit, along with a control element that forecasts energy needs and determines an optimal control strategy to match consumption requirements.
Achieves energy savings by precisely sizing the regeneration unit to meet consumption needs, avoiding oversizing and optimizing energy use.
Smart Images
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Abstract
Description
Title of the invention: Device for the production and use of a heat transfer fluid in a closed circuit. Technical field
[0001] The present invention relates to the field of production and use of a heat transfer fluid. More particularly, it relates to a device for optimizing the production of thermal or cooling energy according to consumption needs.
[0002] The invention finds a particularly advantageous application for achieving energy savings. Previous technique
[0003] When a system uses a heat transfer fluid as a carrier of thermal or cooling energy, it is known to use a buffer tank. The buffer tank allows the heat transfer fluid to be stored at a certain "hot" or "cold" temperature, for injection into a consumption circuit. The consumption circuit may correspond, for example, to a circuit with radiators to heat a dwelling or a circuit with heat exchangers to cool a room, for example, a cold storage room.
[0004] The buffer tank therefore allows a temporal decorrelation, at least partial, of the production of the heat transfer fluid and its use.
[0005] After the heat transfer fluid has been used to provide thermal or cooling energy, the thermal power of the heat transfer fluid is reduced. The heat transfer fluid is then "warm," either because the heat transfer fluid is initially "hot" and its temperature has decreased after circulating in the consumption circuit, or because the heat transfer fluid is initially "cold" and its temperature has increased after circulating in the consumption circuit.
[0006] Two solutions are then possible.
[0007] The "warm" heat transfer fluid can be reinjected directly into the buffer tank, which has the disadvantage of lowering the thermal power of the entire heat transfer fluid in the tank, either by decreasing the temperature of a "hot" heat transfer fluid, or by increasing the temperature of a "cold" heat transfer fluid.
[0008] Alternatively, thermal power can be reinjected into the "warm" heat transfer fluid, i.e., the "warm" heat transfer fluid can be heated or cooled before its reinjection into the buffer tank. In this case, the "warm" heat transfer fluid can be stored before and / or after its heating or cooling. Cooling is carried out in one or more intermediate storage tanks, which has the disadvantage of increasing the overall size of the installation. Without an intermediate storage tank, the "warm" heat transfer fluid must be heated or cooled at a flow rate equivalent to the outlet flow rate of the buffer tank, which necessitates a large-capacity heat transfer fluid regeneration unit. This regeneration unit can typically be a heat pump or a chiller.
[0009] In order to offer a solution to these drawbacks, document DE3115988 proposes a buffer tank comprising a flexible membrane, separating a preheated liquid and a hot liquid.
[0010] However, the solution presented in this document does not allow for taking into account the energy requirements of the installation, in order to optimally control the inputs and outputs of the buffer tank and the heat transfer fluid regeneration unit.
[0011] The technical problem of the invention is therefore to be able to take into account the forecast requirements for thermal or cooling energy in order to control an installation in an optimal way, which makes it possible to save energy and to use an installation that is best sized according to the needs. Description of the invention
[0012] The present invention aims to address this technical problem by using a device for the production and use of a heat transfer fluid in a closed circuit according to operating cycles, the device comprising: - a buffer tank comprising two compartments, a recovery compartment and a storage compartment separated by a flexible membrane, said buffer tank having an inlet and an outlet connected to the recovery compartment, and an inlet and an outlet connected to the storage compartment, - a fluid consumption circuit, extending between the outlet of the storage compartment and the inlet of the recovery compartment of the buffer tank, - at least one heat transfer fluid consumption unit, configured to extract, for a predetermined period less than the duration of an operating cycle, heat or cooling from the heat transfer fluid at the level of the fluid consumption circuit, - a regeneration fluid circuit, extending between the outlet of the recovery compartment and the inlet of the buffer tank storage compartment, and - at least one controllable heat transfer fluid regeneration unit, configured to supply heat or cooling to the heat transfer fluid at the level of the regeneration fluid circuit.
[0013] This device is particular in that it comprises a control element for said at least one regeneration unit, said control element comprising: - means of recovering a forecast of the energy needs of said at least one consumption unit over time over the entire duration of an operating cycle; - search means configured to take into account said forecast and determine an optimal control strategy of said regeneration unit in which the regeneration unit provides the required amount of energy throughout the duration of the operating cycle; the control device being configured to apply said optimal control strategy to said regeneration unit.
[0014] Thanks to these provisions, the regeneration unit can be controlled to meet the needs of the consumption unit, while avoiding excessive energy consumption. Energy savings are thus achieved compared to existing systems. Furthermore, the device, and more specifically the power of the regeneration unit, can be precisely sized according to the needs of the consumption unit, thereby preventing oversizing.
[0015] The search means can be configured to take into consideration an estimate of the heat losses in the consumption fluid circuit when determining the control strategy, which makes it possible to improve the accuracy of the search for the optimal control strategy.
[0016] In addition, the search means can be configured to take into consideration an estimate of the heat losses in the regeneration fluid circuit when determining the control strategy, which also improves the accuracy of the search for the optimal control strategy.
[0017] The search means can also be configured to take into consideration an estimate of the heat losses in the storage compartment of the buffer tank when determining the pilot strategy, this estimate taking into account the storage time of the heat transfer fluid in the storage compartment, which further improves the accuracy of the search for the optimal pilot strategy.
[0018] Alternatively or in addition, the search means can be configured to take into account a forecast of the evolution of the outside temperature when determining the control strategy, which further improves the accuracy of the search for the optimal control strategy.
[0019] In the storage compartment, said heat transfer fluid can be in the state of superheated water, which makes it possible to store a large amount of heat in a restricted volume.
[0020] The buffer tank may comprise two detachable shells, and the flexible membrane is fixed between the two shells, which is a simple and effective way of making a device according to the invention.
[0021] The buffer tank may include at least one position sensor capable of detecting the position of the membrane, which allows for more precise control of the device.
[0022] The membrane can be configured so that the volume occupied by each compartment is variable between 10 and 90% of the total volume of the buffer tank, which increases the flexibility of use of the device according to the invention.
[0023] The present invention also relates to a method of using a device according to the invention, comprising an operating cycle including the following steps: - heating of the heat transfer fluid in the regeneration circuit and storage of the heat transfer fluid in the storage compartment, until a target quantity of heat transfer fluid to be stored is reached, this step being carried out over an initial period of time; and - sending the heat transfer fluid stored in the storage compartment to the consumption fluid circuit, this step being carried out during a second period of time less than said second period of time.
[0024] Thanks to these provisions, the power required in production can be less than the power required in consumption, which makes it possible to use a less powerful regeneration unit for identical needs. Brief description of the drawings
[0025] The present invention and its advantages will become more apparent from the following description of several embodiments given by way of non-limiting examples, with reference to the accompanying drawings, in which:
[0026] [Fig-1] [Fig.1] is a schematic view of a device according to a mode of preferred embodiment of the invention,
[0027] [Fig.2] [Fig.2] is a longitudinal cross-sectional view of the buffer tank of a device according to one embodiment of the invention, and
[0028] [Fig.3] [Fig.3] is a cross-sectional view of the buffer balloon of [Fig.2], with three different positions of the flexible membrane. Description of the implementation methods
[0029] The device according to the invention, illustrated in a preferred embodiment in [Fig.1], makes it possible to produce and use a heat transfer fluid, in a closed circuit, according to operating cycles.
[0030] The heat transfer fluid is, for example, water, or water mixed with one or more additives, allowing its thermodynamic properties, such as its phase change temperatures, and / or its mechanical properties, such as its viscosity, to be modified. The choice of heat transfer fluid depends on the type of application, and in particular the temperatures at which it is used. In the device according to the invention, the fluid The heat transfer fluid can be used at a constant pressure throughout the device and not vary over time, or its pressure can vary depending on the area of the device and / or over time. The pressure(s) used can be atmospheric pressure, or pressures lower or higher than atmospheric pressure.
[0031] The term "closed circuit," in the context of the present invention, refers to the fact that most of the heat transfer fluid circulates regularly throughout the entire circuit. This does not preclude adding or removing certain quantities of heat transfer fluid at one or more points in the circuit to compensate for any losses or to adjust the heat transfer fluid charge in the circuit as needed.
[0032] The operating cycles of the device according to the invention correspond to cycles of heat or cooling demand of the system. These cycles correspond, for example, to the operating cycles of a machine consuming heat or cold, for example, a machine requiring a certain amount of thermal energy every hour for 5 minutes.
[0033] The device according to the invention comprises a buffer balloon 1 having a recovery compartment 2a, and a storage compartment 2b, separated by a flexible membrane 3.
[0034] The buffer tank 1 has a first inlet 4a, and a first outlet 5a, located at the level of the recovery compartment 2a. The first inlet 4a, respectively first outlet 5a, allows heat transfer fluid to pass between the outside of the buffer tank 1 and the recovery compartment 2a, without passing through the storage compartment 2b.
[0035] Similarly, the buffer tank 1 has a second inlet 4b, and a second outlet 5b, located at the level of the storage compartment 2b. The second inlet 4b, respectively second outlet 5b, allows heat transfer fluid to pass between the outside of the buffer tank 1 and the storage compartment 2b, without passing through the recovery compartment 2a.
[0036] The device according to the invention further comprises a fluid consumption circuit 6, extending between the second outlet 5b and the first inlet 4a, i.e., it is configured to transport the heat transfer fluid from the storage compartment 2b to the recovery compartment 2a. Within the fluid consumption circuit 6, the device according to the invention comprises at least one consumption unit 7. The consumption unit 7 is configured to extract heat or cooling from the heat transfer fluid for a predetermined period shorter than the duration of an operating cycle. For example, this could be a heat exchanger controlled to regularly extract the energy required for the operation of a machine or for maintaining a certain temperature in a space or tank containing a product to be heated.
[0037] The device according to the invention further comprises a regeneration fluid circuit 8, extending between the first outlet 5a and the second inlet 4b, i.e., it is configured to transport the heat transfer fluid from the recovery compartment 2a to the storage compartment 2b. Within the regeneration fluid circuit 8, the device according to the invention comprises at least one regeneration unit 9. The regeneration unit 9 is configured to supply heat or cooling to the heat transfer fluid so that it can be extracted by the consumption unit 7. The regeneration unit 9 may be a heat pump, a boiler, or any other means suitable for the particular application of the invention.
[0038] The flexible membrane 3 allows the volumes of the recovery compartment 2a and storage compartment 2b to vary, the sum of these volumes remaining constant and corresponding to the usable volume of the buffer tank 1. Indeed, during an operating cycle of the device, which operates in a closed circuit, the maximum occupancy of the recovery compartment 2a and the storage compartment 2b does not occur simultaneously. By considering the maximum sum of the volumes of the two compartments 2a and 2b during a cycle, and not the sum of the maximum volumes, it is therefore possible to size the system with a buffer tank 1 of smaller volume.
[0039] The device according to the invention comprises a control element 10 for the regeneration unit 9. In order to optimize the operation of the device, the control element 10 includes means for retrieving a forecast 11 of the energy requirements of the consumption unit 7 over time throughout the duration of an operating cycle. The forecast 11 is, for example, a computer file in the form of a table, in which, for each subdivision of a cycle, a subdivision corresponding, for example, to one minute, corresponds to an energy requirement of the consumption unit. These energy requirements can be translated into a supply of heat transfer fluid in the consumption fluid circuit 6 at the level of the consumption unit 7, the heat transfer fluid being heated to a certain temperature and delivered at a certain flow rate.
[0040] The control unit can also control one or more valves and / or one or more pumps, located in one or more locations of the device according to the invention, for the needs of the application case of the invention.
[0041] One can, for example, imagine an operating cycle lasting one hour, in which: - During the first five minutes, the consumption unit 7 requires a heat transfer fluid at a temperature of 120°C, at a flow rate of 80 liters per minute, - During the last 55 minutes, consumption unit 7 does not require any energy input.
[0042] Based on forecast 11, the control unit 10 uses its research means to determine an optimal control strategy for the regeneration unit 9. This optimal control strategy must make it possible to meet the needs listed in forecast 11 throughout the duration of the operating cycle of the device, while minimizing the energy consumed by the regeneration unit 9.
[0043] In order to improve the accuracy of the search for the optimal strategy, the search means of the control unit 10 may take into account certain elements that can influence the temperature of the heat transfer fluid at different locations in the device. It may be possible to choose to take into account one or more of these elements, individually or in combination, depending on their respective importance in the different use cases.
[0044] The research means may take into account an estimate of the heat losses in the fluidic circuit of consumption 6 and / or regeneration 8. These estimates may be determined by calculations, or by one or more test cycles.
[0045] The search means may also take into account an estimate of the heat losses in the storage compartment 2b of the buffer tank 1, this estimate taking into account the storage time of the heat transfer fluid in the storage compartment 2b. This estimate may be determined by calculations, or by one or more test cycles.
[0046] The search methods may also take into account a forecast of the evolution of the outside temperature 1. This forecast can in particular be used to refine the estimates listed above.
[0047] The device according to the invention allows a certain quantity of heat or cooling to be stored in the storage compartment 2b, for use by the consumption unit 7. Since the storage compartment 2b is separated from the recovery compartment 2a by the membrane 3, the warm heat transfer fluid from the consumption circuit 6 is not mixed with the hot or cold heat transfer fluid from the regeneration circuit 9. This allows for optimized programming of the device. Thus, if, for example, the consumption unit 7 only needs heat or cooling during certain time intervals of the device's operating cycle, for example, 5 minutes every hour, then the remainder of the cycle can be used to build up the necessary energy reserve in the storage compartment 2b.The power of the regeneration unit 9 therefore does not need to be sized according to the maximum power of the consumption unit 7. The power of the regeneration unit can be sized according to the power. average consumption of unit 7 over a device operating cycle. This advantage is particularly relevant for heating systems. Indeed, in prior art heating systems, the heat transfer fluid is often used in vapor form. Since vapor is difficult to store, notably because it occupies a significant volume, it is necessary to size the regeneration unit's power output to exceed the consumption power, as production must keep pace with consumption in real time. In the device according to the invention, the heat transfer fluid in the storage compartment 2b is not, or only very slightly, mixed with the heat transfer fluid in the recovery compartment 2a.This allows the heat transfer fluid to be stored in a superheated water state, with the temperature of the heat transfer fluid in the storage compartment 2b being almost equal to the temperature of the heat transfer fluid at the outlet of the regeneration unit 9, and this throughout the consumption of the storage volume 2b, without a thermal mixing front.
[0048] The buffer tank 1 preferably comprises two removable shells, and the flexible membrane 3 is fixed in the buffer tank 1 between the two shells.
[0049] The membrane 3 preferably extends parallel to the largest dimension of the buffer balloon 1, in order to limit its movements during the variation of the volumes of compartments 2a, 2b.
[0050] The pressure of the two compartments 2a, 2b is preferably equal.
[0051] The membrane 3 is set in motion automatically when the volumes of compartments 2a, 2b, i.e. by the inlets and outlets of heat transfer fluid of compartments 2a, 2b. The movements of the membrane 3 allow the volume occupied by each compartment 2a, 2b to be variable, for example between 10 and 90% of the total volume of the buffer tank 1. The movements of the membrane are illustrated by [Fig.3], on which three different positions of the membrane 3A, 3B and 3C are shown.
[0052] As illustrated in [Fig. 2], the membrane can, for example, be connected to the inner surface of the buffer tank 1 by hinges 12. The hinges 12 are preferably attached to the membrane 13 by means of a mounting plate 13. If the surface of the buffer tank 1 has rounded parts, for example in the case of GRC bottoms, fixed hinge supports 14 can be attached to these rounded parts. The hinge supports 14 then have a first rounded side 15a, conforming to the curve of the inner surface of the buffer tank 1, and a second straight side 15b, forming the axis of rotation of the hinges 12, and on which the hinges 12 are attached.
[0053] The buffer tank 1 is, for example, a cylindrical tank, closed by two GRC (Large Radius Square) ends. The buffer tank 1 can then comprise 12 hinges 12, distributed as follows: - four hinges 12 fixed directly to the walls of the cylinder, two of which are on each side of the membrane 3, - eight hinges 12 fixed two by two on four hinge supports 14, two hinge supports 14 being fixed on each GRC base.
[0054] The seal between the recovery compartment 2a and the storage compartment 2b may not be total. In particular, compartments 2a and 2b may be made to communicate, in order to use a common air vent 16 in the upper part of the buffer tank 1, and a common drain vent 17 in the lower part of the buffer tank 1.
[0055] As illustrated in [Fig.3], the buffer tank 1 may include at least one position sensor 18 capable of detecting the position of the membrane 3. This makes it possible to estimate the volumes occupied by each compartment 2a, 2b, and this information can be transmitted to the control unit 10. Different types of sensor can be used: infrared sensor, inductive sensor, etc. A single sensor 18 can be disposed at the center of the membrane 3, or several sensors 18 can be distributed over the surface of the membrane 3. In order to detect the position of the membrane 3, the buffer balloon 1 can include a tube 19, passing through the inside of the buffer balloon 1 in a direction parallel to the movement of the membrane 3. The tube 19 passes through the membrane, preferably at its center, and the membrane has a target disposed near the tube 19. The position sensor 18, by detecting the position of the target 19, can thus detect the position of the membrane 3. [Fig.3] illustrates this, with the target shown in three different positions 20A, 20B and 20C, corresponding to the membrane positions 3A, 3B and 3C. .
[0056] The device according to the invention can be used according to a method comprising the following steps: - heating of the heat transfer fluid in the regeneration circuit 8 and storage of the heat transfer fluid in the storage compartment 2b, until a target quantity of stored heat transfer fluid is reached, corresponding for example to a volume greater than 50% of the buffer tank, this step being carried out over an initial period of time, for example greater than 50% of an operating cycle; and - sending the heat transfer fluid stored in the storage compartment 2b to the consumption fluid circuit 6, this step being carried out for a second period of time less than said first period of time, for example less than half of the first period of time.
[0057] The present invention is of course not limited to the embodiments described but extends to any modification and variant obvious to a person skilled in the art within the limits of the appended claims. Furthermore, the characteristics The techniques of the different modes of embodiment and variants mentioned above can be, in whole or in part, combined with each other.
Claims
1. Demands A device for the production and use of a heat transfer fluid in a closed circuit according to operating cycles, the device comprising: - a buffer tank (1) comprising two compartments, a recovery compartment (2a) and a storage compartment (2b) separated by a flexible membrane (3), said buffer tank (1) having an inlet (4a) and an outlet (5a) connected to the recovery compartment (2a), and an inlet (4b) and an outlet (5b) connected to the storage compartment (2b), - a fluid consumption circuit (6), extending between the outlet (5b) of the storage compartment (2b) and the inlet (4a) of the recovery compartment (2a) of the buffer tank, - at least one consumption unit (7), configured to extract, for a predetermined period less than the duration of an operating cycle, calories or frigories from the heat transfer fluid at the level of the consumption fluid circuit (6), - a fluid regeneration circuit (8), extending between the outlet (5a) of the recovery compartment (2a) and the inlet (4b) of the storage compartment (2b) of the buffer tank, and - at least one heat transfer fluid regeneration unit (9), configured to supply heat or cooling to the heat transfer fluid at the level of the regeneration fluid circuit (8), characterized in that the device comprises a control element (10) for said at least one regeneration unit (9), said control element (10) comprising: - means of recovering a forecast (11) of the energy requirements of said at least one consumption unit over time over the entire duration of an operating cycle; - search means configured to take into account said forecast (11) and determine an optimal control strategy of said regeneration unit (9) in which the regeneration unit (9) provides the required amount of energy throughout the duration of the operating cycle; the control device (10) being configured to apply said optimal control strategy to said regeneration unit (9).
2. Device for the production and use of a heat transfer fluid according to claim 1, characterized in that the search means are configured to take into consideration an estimate of the heat losses in the consumption fluid circuit (6) when determining the control strategy.
3. Device for the production and use of a heat transfer fluid according to one of claims 1 or 2, characterized in that the search means are configured to take into consideration an estimate of the heat losses in the regeneration fluid circuit (8) when determining the control strategy.
4. Device for the production and use of a heat transfer fluid according to any one of claims 1 to 3, characterized in that the search means are configured to take into consideration an estimate of the heat losses in the storage compartment (2b) of the buffer tank when determining the pilot strategy, this estimate taking into account the storage time of the heat transfer fluid in the storage compartment (2b).
5. Device for the production and use of a heat transfer fluid according to any one of claims 1 to 4, characterized in that the search means are configured to take into consideration a forecast of the evolution of the outside temperature when determining the control strategy.
6. Device for producing and using a heat transfer fluid according to any one of claims 1 to 5, wherein the buffer tank (1) has two removable shells, and the flexible membrane (3) is fixed between the two shells.
7. Device for the production and use of a heat transfer fluid according to any one of claims 1 to 6, wherein the buffer tank (1) includes at least one position sensor capable of detecting the position of the membrane (3).
8. Device for producing and using a heat transfer fluid according to any one of claims 1 to 7, wherein the membrane (3) is configured so that the volume occupied by each compartment (2a, 2b) is variable between 10 and 90% of the total volume of the buffer tank (1).
9. A method of using a device according to any one of claims 1 to 8, comprising an operating cycle including the following steps: - heating of the heat transfer fluid in the regeneration circuit (8) and storage of the heat transfer fluid in the storage compartment (2b), until a target quantity of heat transfer fluid to be stored is reached, this step being carried out over a first period of time; and - sending the heat transfer fluid stored in the storage compartment (2b) to the consumption fluid circuit (6), this step being carried out over a second period of time shorter than said first period of time.
10. A method of using a device according to any one of claims 1 to 8, characterized in that in the storage compartment (2b), said heat transfer fluid is at least partly in the state of superheated water.