Improved recovery unit, sterilization device and associated process.

Abstract

Improved recovery unit, sterilization device and associated process. The invention relates to a recovery unit (10) comprising: a heat exchanger (102), a storage module (100) comprising two tanks (110, 120) including a first injection and withdrawal system (108) for a storage fluid in the lower part (110b) of the tank (110, 120), a storage circuit (101) connecting the storage module (100) and the heat exchanger (102), the tanks (110, 120) having a fill level (50) of storage fluid, and the tanks (110, 120) each comprising a second injection and withdrawal system (111) comprising: a body (1110) movable in a vertical direction (z) within the tank (110, 120), and an injection and withdrawal module (1111) for the storage fluid (5) so as to draw and inject said fluid (5) at a variable height depending on the fill level. Figure for the abbreviation: Fig. 2

Description

Title of the invention: Improved recovery unit, sterilization device and associated process. technical field

[0001] The present invention relates to the field of energy recovery and optimization of the use of thermal energy. It finds a particularly advantageous application in the field of sterilizers using heat intermittently to carry out a sterilization cycle. STATE OF THE ART

[0002] The ecological optimization of industrial equipment and processes is an approach in which manufacturers are increasingly engaged. In addition to having a positive impact on the environment, ecological optimization contributes to the company's image. Ecological optimization commonly involves energy optimization, leading to cost reductions.

[0003] Among the industrial processes that can be optimized, sterilization devices and processes are major consumers of energy and water, a large portion of which is not recycled. One area of ​​research concerns the storage of waste energy generated by these sterilization processes.

[0004] A first, seemingly obvious and simple thermal storage solution would consist of filling a tank with the hot water recovered during the sterilizer's cooling phase, and then releasing the heat from this stored hot water during the heating phase of the following cycle. In this configuration, the collected hot water is mixed in the storage tank with the water already present, leading to a gradual homogenization of its temperature. Despite its simplicity, this system has a very restrictive operational limitation, since during the subsequent heating phase of the sterilizer, the heat storage solution can only be used as long as the temperature of the water at its outlet allows it to maintain the temperature of the process water supplying the sterilizer.However, the homogenization of water temperature during its recovery and storage greatly limits the possibilities of exploiting this recovered heat and leads to considering large storage volumes in order to ultimately utilize only a small amount of thermal energy.

[0005] A recovery unit comprising a thermal energy storage module receiving a storage fluid, a heat exchanger, and a thermal storage circuit fluidly connecting the storage module and the heat exchanger and ensuring the circulation of the fluid is known from document EP3882555 Al storage. The heat exchanger is intended to be associated with a sterilizer to exchange thermal energy between the sterilizing fluid circulating in the sterilizer and the storage fluid.

[0006] This energy recovery unit utilizes the physical effect known as the "thermocline," and thus the natural temperature stratification of the storage fluid in the tank. The storage fluid intended for storage in the storage module represents a volume smaller than the volume of the storage module in order to maintain a void volume, referred to as a buffer volume. The energy storage module further comprises at least two sensible heat storage tanks. Each tank is equipped with a storage fluid injection and withdrawal system arranged in the lower part of the tank, for drawing in or injecting the storage fluid.

[0007] However, this type of storage is not optimal for the recovery and reuse of waste heat. In particular, the storage fluid is not stored optimally during the heat release phases. Furthermore, in this system, the withdrawal of the storage fluid may not optimally follow the temperature setpoint during a sterilization cycle.

[0008] An object of the present invention is therefore to provide a solution that improves the recovery and utilization of recovered thermal energy. More particularly, an object of the present invention is to provide a solution that improves the recovery of thermal energy from systems involving a process with an initial temperature rise phase (heating) and / or a temperature fall phase (cooling), such as sterilizers.

[0009] The other objects, features and advantages of the present invention will become apparent from an examination of the following description and accompanying drawings. It is understood that other advantages may be incorporated. SUMMARY

[0010] To achieve this objective, according to a first aspect, a valuation unit is envisaged comprising: - a heat exchanger, - a thermal energy storage module configured to receive a storage fluid, the storage module comprising at least two tanks, each intended to receive the storage fluid and each comprising a first injection and withdrawal system for the storage fluid arranged in the lower part of said tank, the first injection and withdrawal system being configured to draw and inject the storage fluid into the lower part of said tank, the storage module further comprising an empty volume called a buffer volume, the storage fluid intended to be stored in the storage module representing a volume smaller than the volume of the storage module in order to maintain the buffer volume, - a thermal storage circuit configured to fluidly connect the storage module and the heat exchanger to ensure the circulation of the storage fluid.

[0011] Advantageously, the at least two tanks are designed to have a fill level of storage fluid, separating a filled sub-volume and an empty sub-volume, and in that the at least two tanks each include a second injection and withdrawal system for the storage fluid, each second injection and withdrawal system comprising: - a body configured so as to be at least partially mobile along a vertical direction within said reservoir, and - a storage fluid injection and withdrawal module fluidically connected to the body, in order to draw and inject the storage fluid at a variable height, said height being a function of the level of filling with storage fluid of said tank.

[0012] Thus, the recovery unit allows for the injection and withdrawal of the storage fluid at the storage fluid filling level in the tank in question. For example, during the discharge of the thermal storage means, i.e., the heating of the process by releasing the stored heat, the invention makes it possible to inject the flow rate of the storage fluid at the storage fluid filling level (i.e., from bottom to top) into the tank selected for filling, so as to store the storage fluid in the direction of temperature stratification.

[0013] During the charging of the thermal storage means, i.e. the cooling of the process by recovering its heat, the invention makes it possible to take the flow of the storage fluid from top to bottom (at the level of the free surface), i.e. in the direction of the temperature stratification, in the tank selected to be emptied.

[0014] In existing solutions that only involve injection and withdrawal from the bottom of the tanks, during the discharge of the thermal storage device, i.e., when the stored heat is to be released, and particularly during the heating phase of a sterilizer, the fluid is withdrawn from a first tank, circulates in the storage circuit to the heat exchanger, and is then reinjected into a second tank as cooled storage fluid. The cooled storage fluid is injected into this second tank from its bottom. However, the temperature of the cooled storage fluid returning to this second tank typically becomes increasingly hot during the heating phase of a sterilizer. Injecting an increasingly hot storage fluid from the bottom is energy-inefficient because it leads to a degradation of energy quality (exergy). stored, due to the convection movements initiated which promote the mixing and homogenization in temperature of the storage fluid in the tank concerned.

[0015] In these existing solutions, during the charging of the thermal storage system, i.e., the cooling of the process by recovering its (waste) heat, the flow of the storage fluid drawn from the tank selected for emptying is taken from the bottom of that tank. If temperature stratification of the storage fluid has nevertheless developed (despite the previous consideration during the preceding discharge) in the emptied tank, the flow drawn will be increasingly warm, while the cooling requires an increasingly cold heat source. Depending on the heat exchange conditions, this operation can constrain and limit the operation of the energy recovery system (for example, by requiring the tank being emptied to be changed to a colder one even though the one being emptied is not yet empty).

[0016] It is therefore understood that the recovery of thermal energy is improved, particularly for a system involving a schedule with a first phase of temperature rise (heating), and / or a phase of temperature fall (cooling), such as a sterilizer.

[0017] A second aspect relates to a sterilization device comprising a sterilizer and a recovery unit according to the first aspect.

[0018] According to one example, the sterilization device includes a cold source inlet different from the storage fluid and a hot source inlet different from the storage fluid.

[0019] A third aspect relates to a process for recovering thermal energy by a recovery unit according to the first aspect, the recovery unit receiving a storage fluid, the process comprising a step of charging the storage module comprising: - the withdrawal of the storage fluid by the second injection and withdrawal system from one of the at least two storage tanks, to a height in said tank depending on the level of filling in storage fluid, for the circulation of the storage fluid in the storage circuit in order to exchange thermal energy in the heat exchanger, - the injection of the storage fluid into the buffer volume.

[0020] A fourth aspect, possibly combinable with the process according to the third aspect, concerns a process for recovering thermal energy by a recovery unit according to the first aspect, the recovery unit receiving a storage fluid, the process comprising a step of discharging the storage fluid comprising: - the withdrawal, by the first injection and withdrawal system, of the storage fluid from the lower part of a storage tank, from among at least two storage tanks for the circulation of the storage fluid in the storage circuit in order to exchange thermal energy in the heat exchanger, - the injection of the storage fluid into the buffer volume. BRIEF DESCRIPTION OF THE FIGURES

[0021] The aims, objects, features and advantages of the invention will become clearer from the detailed description of an embodiment thereof, which is illustrated by the following accompanying drawings in which:

[0022] [Fig. 1] The [Fig. 1] is a graph of the setpoint temperature of the sterilizing fluid according to the phase of the cycle, also called the schedule, as a function of time in a sterilizer during a sterilization cycle, according to an example.

[0023] [Fig.2] [Fig.2] shows a piping and instrumentation diagram (in English Simplified Piping and Instrumentation Diagram or Process and Instrumentation Diagram (abbreviated P&ID) of a superheated pressurized storage fluid sterilization device, incorporating the recovery unit according to an example in which the recovery unit comprises two tanks.

[0024] [Fig. 3] Figure 3 shows a piping and instrumentation diagram (P&ID), according to an example in which the storage module 100 of the recovery unit comprises four tanks, during a charging phase. The second injection and withdrawal systems are mounted on the upper part of the tank in this example.

[0025] [Fig.4] Fig.4 represents a piping and instrumentation diagram (P&ID) according to the example illustrated in [Fig.3], during a discharge phase.

[0026] [Fig.5] Figures 5 and 6 represent a diagram of a tank comprising a second injection and withdrawal system mounted at the top of the tank, according to an example, respectively during and at the end of injection when the tank is filled.

[0027] [Fig.6]

[0028] [Fig. 7] Figures 7 and 8 represent a diagram of a reservoir comprising a second injection and withdrawal system mounted in the lower part of the tank, according to an example, respectively at the beginning and during injection.

[0029] [Fig.8]

[0030] [Fig.9] The [Fig.9] represents a piping and instrumentation diagram (P&ID), according to an example in which the storage module 100 of the recovery unit comprises four tanks, during a charging phase. The second systems The injection and withdrawal points are mounted in the lower part of the tank in this example.

[0031] [Fig. 10] The [Fig. 10] represents a piping and instrumentation diagram (P&ID) according to the example illustrated in [Fig.9], during a discharge phase.

[0032] [Fig. 11] The [Fig. 11] represents a cross-sectional view of the body of an injection and withdrawal system, according to an example.

[0033] The drawings are given by way of example and are not limiting of the invention. They constitute schematic representations of principle intended to facilitate understanding of the invention and are not necessarily to scale with practical applications. DETAILED DESCRIPTION

[0034] Before beginning a detailed review of embodiments of the invention, optional features which may possibly be used in association or alternatively are stated below.

[0035] According to one example, the energy storage module and the first and second and the storage fluid injection and withdrawal system are configured to promote the formation and maintenance of temperature stratification.

[0036] According to one example, the body of at least one, and preferably each, second injection and withdrawal system has a deployed configuration and a plurality of retracted configurations, so as to modify the body's length along the vertical z-direction as a function of the storage fluid filling level. The second injection and withdrawal system thus adapts flexibly to the filling level by contracting or deploying along the vertical z-direction. This limits the disturbance of stratification in the retracted configurations compared to a fixed-length device that would be more or less twisted depending on the storage fluid filling level. The thermal mixing of the storage fluid in the tanks can therefore be limited during the injection and withdrawal of the storage fluid.

[0037] According to one example, the body of at least one, and preferably of each, second injection and withdrawal system is telescopic and slides along a main direction of body deployment.

[0038] According to one example, the body has an internal hydraulic cross-section, taken substantially perpendicular to the main direction of deployment of the body, increasing along the main direction of deployment towards the injection and withdrawal module. The second injection and withdrawal system thus progressively reduces the flow velocity of the storage fluid up to the point hydraulic injection or withdrawal, which is more favorable for controlling thermal stratification within the reservoir.

[0039] According to one example, the body of said second injection and withdrawal system comprises: - a set of coaxial telescopic tubes configured together to slide along the main direction of deployment of the body, and - a rotational locking device, around the main direction of deployment of the body, of the telescopic tubes relative to each other.

[0040] The locking device ensures the centering of the coaxial telescopic tubes and prevents their rotation, so that the body of the second injection and withdrawal system moves only in translational motion. Thermal mixing of the storage fluid in the tanks can therefore be further limited during the contraction and extension of the body, and thus during the injection and withdrawal of the storage fluid.

[0041] According to one example, the at least two tanks have an upper portion in which the body of at least one, and preferably of each, second injection and withdrawal system extends from the upper portion of said tank so as to extend primarily within the empty sub-volume. The moving body of the second injection and withdrawal system is therefore primarily mobile within the empty sub-volume. This minimizes the disturbance of the storage fluid during the adaptation of the second injection and withdrawal system to the fill level. The thermal stratification within the tank is thus better preserved.

[0042] According to one example, at least one and preferably every second injection and withdrawal system is configured to draw and inject the storage fluid, via the injection and withdrawal module, at a distance extending into the filled sub-volume from the filling level, the distance being, for example, between 0 cm and 20 cm. The closer the injection is to the free surface, the more optimized the thermal stratification.

[0043] According to one example, the injection and withdrawal module of at least one, and preferably of each, second injection and withdrawal system includes a flotation device. This allows the injection and withdrawal system to passively follow changes in the storage fluid level in the tank. In particular, the flotation device ensures that the injection or withdrawal of the storage fluid occurs just below or at the level of the liquid free surface of the storage fluid contained in the tank.

[0044] According to one example, the injection and withdrawal module of at least one, and preferably of each, second injection and withdrawal system is configured to inject or withdraw the storage fluid radially. The distribution of the The velocity profile of the injected or withdrawn storage fluid flow rate is thus made more homogeneous. This limits the temperature mixing phenomenon between the volume of storage fluid contained in the tank at the injection or withdrawal point and the injected or withdrawn storage fluid flow rate.

[0045] According to one example, said injection and withdrawal module comprises at least two plates at least partially superimposed along the vertical direction z, the at least two plates delimiting a spacing having a rotational symmetry around the vertical direction z and allowing the injection and withdrawal of the storage fluid.

[0046] According to one example, the recovery unit further comprises, for each of the at least two tanks, a first fluid-selective valve connected to the first injection and withdrawal system, and a second fluid-selective valve connected to the second injection and withdrawal system. The first and second selection valves are configured to select one of the first and second injection systems to inject or withdraw the storage fluid. Thus, the unit allows the selection of one or the other of the injection and withdrawal systems depending on the stage of the cycle, so as to optimize temperature stratification.

[0047] According to one example, the thermal storage circuit comprises, for each of the at least two tanks, a first pipe intended to convey the storage fluid to the inlet of said tank and a second pipe intended to convey the storage fluid (5) to the outlet of said tank, and a third pipe forming a common sub-branch of the first and second pipes, and positioned downstream of the first pipe and upstream of the second pipe in the direction of flow of the storage fluid, the first and second selection valves being fluidly connected to the third pipe.

[0048] According to one example, the recovery unit includes a storage module management module configured to control the injection and withdrawal system of the storage fluid according to a temperature setpoint in the heat exchanger.

[0049] According to one example, the buffer volume corresponds to the volume of at least one reservoir.

[0050] According to one example, the thermal storage circuit is configured to operate in closed circuit

[0051] According to one example, the storage module includes a system for homogenizing and distributing the flow of the storage fluid injected throughout the hydraulic section of at least two tanks.

[0052] According to one example, the recovery unit includes a pressurization module for at least two storage tanks configured to maintain sufficient pressure to keep the storage fluid in a liquid state.

[0053] According to one example, the storage module comprises four tanks.

[0054] According to one example, the recovery unit includes the storage fluid.

[0055] According to one example, the storage fluid is water.

[0056] According to one example, during the withdrawal, the tank from which the fluid is withdrawn storage includes the storage fluid exhibiting temperature stratification.

[0057] According to one example, during the injection step, the buffer volume is a different tank from the storage tank from which the storage fluid is drawn, the storage fluid is injected into the lower part of the tank by the first injection and withdrawal system and arrives increasingly colder, ensuring thermal stratification of the storage fluid in the buffer volume.

[0058] According to one example, the control of the injection and withdrawal system of the storage fluid is based on a temperature setpoint in the heat exchanger, and is carried out by the management module of the storage module.

[0059] According to an example, during the withdrawal stage, the storage fluid is withdrawn from the tank, comprising the temperature-stratified storage fluid, the withdrawal being carried out from the lower part, the sampling begins with the coldest storage fluid and progresses to the warmest.

[0060] According to an example, during the injection step, the buffer volume is a different tank from the storage tank from which the storage fluid is drawn, the storage fluid is injected by the second injection and withdrawal system from said storage tank, to a height in said tank depending on the level of filling in storage fluid, and arrives increasingly hot and is thermally stratified as the storage fluid is injected into said tank.

[0061] According to one example, the valorization unit further comprising, for each of the at least two tanks, a first fluidly connected selection valve to the first injection and withdrawal system, and a second fluidly connected selection valve to the second injection and withdrawal system, the process further comprises a selection of the injection and withdrawal system to be used, from among the first and second injection and withdrawal systems.

[0062] In the following description, the term "on" does not necessarily mean "directly on." Thus, when it is stated that a part or component A is supported "on" a part or component B, this does not mean that parts or components A and B are necessarily in direct contact with each other. These parts or components A and B may be either in direct contact or supported by each other via one or more other parts. The same applies to other expressions such as, for example, the expression "A acts on B," which may mean "A acts directly on B" or "A acts on B via one or more other parts."

[0063] In the present patent application, the term mobile corresponds to a rotational movement or a translational movement or a combination of movements, for example the combination of a rotation and a translation.

[0064] In this patent application, when two parts are described as distinct, this means that these parts are separate. They may be: - positioned at a distance from each other, and / or - mobile relative to each other and / or - joined together by being fixed by added elements, this fixing being removable or not.

[0065] A single-piece unit cannot therefore be made up of two separate parts.

[0066] In this patent application, the term "fixed" used to describe the connection between two parts means that the two parts are linked / fixed to each other with respect to all degrees of freedom, unless explicitly specified otherwise. For example, if it is stated that two parts are fixed in translation along a direction X, this means that the parts can be movable relative to each other, possibly with respect to several degrees of freedom, excluding freedom in translation along the direction X. In other words, if one part is moved along the direction X, the other part moves in the same direction.

[0067] In the detailed description that follows, terms such as "horizontal", "vertical", "longitudinal", "transverse", "upper", "lower", "top", "bottom", "front", "back", "inside", and "outside" may be used. These terms must be interpreted relatively in relation to the normal position of the processing unit. For example, the term "vertical" corresponds to the normal to the free surface of a fluid in a tank.

[0068] A reference frame will also be used whose longitudinal or rear / front direction corresponds to the X axis, the transverse or right / left direction corresponds to the Y axis and the vertical or bottom / top direction corresponds to the Z axis.

[0069] For the purposes of this disclosure, the expression "A and / or B" means (A), (B), or (A and B). For the purposes of this disclosure, the expression "A, B and / or C" means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C).

[0070] A parameter "approximately equal to / greater than / less than" a given value means that this parameter is equal to / greater than / less than the given value, to within ±10% of that value. A parameter "approximately between" two given values ​​means that this parameter is at least equal to the smaller of the given values, to within ±10% of that value, and at most equal to the larger of the given values, to within ±10% of that value.

[0071] The invention is now described with reference to several specific embodiments in the figures. In the following, it is considered, by way of non-limiting example, that the recovery unit 10 is intended to recover and utilize thermal energy with a sterilizer 200, which may also be called an autoclave. Other applications are possible, however, as the invention is particularly advantageous for a system involving a process with a first temperature rise phase (heating) and / or a temperature fall phase (cooling).

[0072] Typically, and as illustrated in [Fig. 1], during a sterilization process, the load inside the sterilizer 200 undergoes a thermal cycle: heating 1, temperature maintenance 2 by a hot source such as a steam-generating boiler F4, and cooling 3 by a cold source F5 such as mains water. The heat discharged into the mains water during the sterilization cycles represents a significant energy resource, typically amounting to approximately 300 kWh to 400 kWh per sterilization cycle. Given that sterilizers perform up to 20 cycles per day at some industrial sites, the discharges exceed 2 GWh and 50,000 m³ of water per year per sterilizer if cooling is provided by an open-loop system (i.e., a wastewater system). Most of the time the cooling water is in a closed circuit and is cooled by a cooling tower (CT).The equivalent annual gas consumption is estimated to be between 93,000 Nm3 and 124,000 Nm3 (in standard cubic meters, a unit of measurement for the quantity of gas corresponding to the contents of a volume of one cubic meter, for a gas under normal temperature and pressure conditions). The equivalent amount of CO2 released (assuming 227 gCO2 / kWh) is estimated to be between 204 and 272 tonnes of CO2 / year.

[0073] The sterilization process is batch-controlled, which does not allow the use of a simple heat exchanger 102 to preheat the water entering the boiler. Using a storage system to recover and store the waste heat for reuse in a subsequent cycle eliminates the problem that the heating 1, temperature maintenance 2, and cooling 3 phases are out of phase and occur at different times.

[0074] The recovery unit 10 at least partially replaces the supply of steam F4 or cold F5 for part of the cycle. As illustrated in [Fig. 1], one objective of the invention is, in particular, to recover F2 and store some of the heat extracted during the cooling 3 of the sterilizer 200 in order to release it Fl to ensure part of the heating phase of a subsequent cycle, for example, the one directly following it. We can therefore distinguish: - a phase 3 of heat recovery or equivalently of charging the storage module 100 (cooling of the sterilizer 200) during which the hot source decreases in temperature, - a phase 1 of heat restitution or equivalently of discharge of the storage module 100 (heating of the sterilizer 200) during which the cold source increases in temperature.

[0075] Because of these temperature scales, the sensible heat storage module 100 is more likely to exhibit a temperature gradient established along its height, rather than a hot (quasi-isothermal) volume separated from a cold (quasi-isothermal) volume by a thermocline thickness, which is the case most commonly encountered when the source temperatures are constant.

[0076] This solution thus makes it possible to save some of the thermal energy required to heat (steam) and cool (cooling water) the sterilizer 200, by utilizing what is currently a source of waste heat. Therefore, when the heat transfer fluid 5, also called the storage fluid, from the storage module 100, is able to heat or cool the sterilizer 200 according to the schedule, the recovery unit 10 can be used to supplement or replace the usual steam or cooling supply methods (also called utilities).As explained later, the recovery unit 10 initially maintains the temperature levels of the recovered waste heat, for example during cooling, and then subsequently releases it in the opposite direction, in a gradually increasing temperature ramp, without altering it, which would reduce its energy recovery. The water from the storage module 100 returns to the storage module 100 after passing through the heat exchanger 102, thus forming the thermal storage circuit 101, which is preferably closed. When the storage module 100 is no longer able to heat or cool the sterilizer 200, the usual means can take over directly.

[0077] The usual means of supplying steam or cold can operate in a clean circuit, independently of the recovery unit 10. The recovery unit 10 makes it possible to minimize their use and therefore the consumption of primary energy, and typically gas.

[0078] As illustrated in [Fig. 2], the recovery unit 10 comprises a thermal storage module 100. The thermal storage module 100 of the recovery unit 10 is advantageously a sensible heat storage unit. The recovery unit 10 according to the invention can be installed on existing or new sterilization plants.

[0079] The thermal storage module 100 is suitable for receiving a storage fluid 5. According to one example, the thermal storage module 100 includes the storage fluid 5.

[0080] The storage fluid 5 is advantageously a heat transfer fluid chosen to operate at the application temperature, in this case for a sterilizer 200. For example, the storage fluid 5 is water. This choice facilitates the successive circulation of the storage fluid 5, a hot source, and a cold source in the heat exchanger 102, and in particular in a first fluid circuit and a second fluid circuit of the heat exchanger 102. The water is preferably pressurized and potentially superheated. Other fluids, such as thermal oil, can be considered.

[0081] The recovery unit 10 according to the invention comprises a thermal storage circuit 101. The thermal storage circuit 101 is a hydraulic circuit, advantageously a circuit capable of operating in a closed loop. The storage circuit 101 is connected to the storage module 100 so as to store and release the storage fluid 5. The storage circuit 101 is capable of receiving the storage fluid 5 and advantageously of ensuring its circulation.

[0082] The recovery unit 10 advantageously comprises a heat exchanger 102. Preferably, the recovery unit comprises a heat exchanger 102 intended to be associated with a sterilizer 200. The association is between a heat exchanger 102 and a sterilizer 200. The heat exchanger 102 is arranged on the thermal storage circuit 101. The storage fluid 5 circulating in the storage circuit 101 exchanges thermal energy in the heat exchanger 102 advantageously with a sterilization fluid intended to circulate in the sterilizer 200 and ensure sterilization. The exchanger 102 can be, for example, a shell-and-tube or plate heat exchanger.

[0083] The recovery unit 10 can, depending on the possibility, include several sterilizers 200. In this way, the recovery unit 10 is shared for several heat exchangers 200.

[0084] The thermal storage module 100 preferably comprises at least two tanks 110, 120, 130, 140. In the following description, the use of the term "tanks" in the plural refers to "at least two tanks." Tanks 110, 120, 130, 140 are understood to be distinct volumes from which the injection and withdrawal of storage fluid 5 is independent. The storage module 100 is configured to allow natural thermal stratification. Advantageously, the tanks 110, 120, 130, 140 extend vertically along the z-direction so as to conform to configurations favorable to the establishment of thermal stratification within their volume.

[0085] Advantageously, according to the invention, the storage fluid 5 intended to be stored in the storage module 100 represents a volume that is less than the volume of the storage module 100 so as to maintain an empty volume in the storage module 100. This buffer volume does not include any storage fluid 5. This empty volume is a buffer volume. The buffer volume is advantageously present in all stages of use of the recovery unit 10, that is to say, during loading and unloading. The buffer volume is intended to allow the injection of storage fluid 5 into the buffer volume when the storage fluid is withdrawn from a tank 110, 120, 130, 140 preferably so as not to mix the storage fluid 5 intended to be withdrawn and the injected storage fluid, i.e. the storage fluid 5 intended for the heat exchanger 102 and the storage fluid returning from the heat exchanger 102.Temporarily, the storage fluid 5 may be drawn off and then injected into the same tank. This situation can occur, for example, when the temperature of the fluid discharged from one of the tanks of the recovery unit is insufficient to meet the temperature setpoint (Tstockfromlimite) required by the schedule. Specifically, this situation arises if, during the storage tank's charging phase (i.e., the cooling of the sterilizer), the temperature of the tank being discharged is higher than the setpoint, or if, during the storage tank's discharge phase (i.e., heating the sterilizer), the temperature of the tank being discharged is lower than the setpoint. This leads to a change in the tank being discharged or to the shutdown of the storage solution, leaving one tank partially emptied and another partially filled.

[0086] The presence of a buffer volume helps ensure thermal stratification for eventual exploitation. The buffer volume increases the thermal energy that can be stored in the storage module 100 and facilitates the storage and release of the storage fluid 5.

[0087] Preferably, the buffer volume corresponds to the volume of at least one reservoir 110, 120, 130, 140. In one embodiment, the reservoir 110, 120, 130, 140 forming the buffer volume changes depending on the storage and release phases of the storage fluid 5; different reservoirs 110, 120, 130, 140 are used alternately as a buffer volume. In another possibility, each reservoir 110, 120, 130, 140 is used alternately as a buffer volume.

[0088] According to one embodiment, the reservoirs 110, 120, 130, 140 are used in communicating vessels.

[0089] In a more advantageous configuration in terms of energy storage density and quality of the stored thermal energy, the storage module 100 is advantageously composed of more than two tanks 110, 120, 130, 140. Indeed, according to the present invention, the more tanks 110, 120, 130, 140 there are, the more efficient the storage is. Importantly, the smaller the (empty) buffer volume is compared to the energy-recovered storage volume. For example, if storage module 100 comprises two tanks (110, 120, 130, 140), only half of the total storage volume is used, whereas if storage module 100 has four tanks, three-quarters of the total storage volume is used. The greater the number of tanks, the lower the ratio of empty tanks to the total number of tanks.

[0090] Similarly, the greater the number of tanks 110, 120, 130, 140, the more it will be possible to create thermal stratification by discretizing the storage tanks filled during the discharge phase, i.e., during the heating of the sterilizer 200, into different homogeneous temperature levels. This phase is difficult to control without modifying the design of the storage module. This configuration is therefore particularly energy-efficient since, at the end of the heating phase of the sterilizer 200, tanks 110, 120, 130, 140 are filled with a storage fluid at different (homogeneous) temperature levels.

[0091] The storage module 100 advantageously includes a first injection and withdrawal system for the storage fluid 108 from the tanks 110, 120, 130, 140. Preferably, the first injection and withdrawal system 108 is arranged in the lower part 110b of each of the tanks 110, 120, 130, 140. Preferably, the storage module 100 includes a first injection and withdrawal system 108 per tank.

[0092] This location in the lower part 110b, however, leads existing recovery solutions, implementing only a first injection and withdrawal system 108, to mix the storage fluid injected into at least one of the tanks 110, 120, 130, 140 during a discharge step of the storage module 100. In these solutions, during this discharge step, and therefore during the heating of the sterilizer 200, a flow of storage fluid 5 returning from the heat exchanger 102 is then injected into a tank via the lower part 110b into a volume of storage fluid 5 already present, which is at a lower temperature. This results in mixing that leads to a temporary homogenization of the temperature of the storage fluid 5 within the tank. The temperature stratification is, at the very least, disrupted, and often lost, at least temporarily.The homogenization of temperature is an inherent consequence of the injection, through the lower part of the tanks, of a flow of warmer storage fluid (returning from the heat exchanger 102) into a volume of colder storage fluid 5 already present in the tank.

[0093] During the withdrawal of the storage fluid 5 from a reservoir to heat the sterilizer 200, the storage fluid is initially stratified into temperature (since it was stratified during the previous cooling phase of sterilizer 200).

[0094] Furthermore, during the charging of the thermal storage module 100, i.e., the cooling of the process by recovering its waste heat from the sterilizer, the flow of the storage fluid 5 drawn from the selected tank to be emptied is drawn from its lower part 110b. In the event that temperature stratification of the storage fluid has nevertheless developed (despite the homogenization considerations mentioned earlier during the preceding discharge) in the emptied tank, the drawn flow will be increasingly warm, while the cooling requires an increasingly cold heat source. Energy recovery is therefore not optimal. Note that for an increasingly cold heat source, the term "cooling source" can be used (to refer to cold as opposed to "calorie" to refer to heat).

[0095] To avoid this, at least two tanks 110, 120, 130, 140, and preferably each tank, include a second injection and withdrawal system 111 for the storage fluid 5. The second injection and withdrawal system 111 is configured to adapt to the fill level 50 of the storage fluid 5 in the corresponding tank. The storage fluid 5 in each tank 110, 120, 130, 140 has a fill level 50, which separates a sub-volume filled with storage fluid 5 from an empty sub-volume. The fill level 50 therefore corresponds to the free surface of the storage fluid 5 in a tank. When the tank is full, the empty sub-volume can be zero. When the tank is empty, the filled sub-volume can be zero.

[0096] The second injection and withdrawal system 111 of the storage fluid 5 is configured to draw and inject the storage fluid at a variable height along the vertical direction z in the tank 110, 120, 130, 140 considered. This height is a function of the level of the storage fluid in the tank.

[0097] More specifically, the second injection and withdrawal system 111 is configured to inject or withdraw the storage fluid 5 at the filling level 50 or just below, and for example at a vertical distance D from the free surface, between 0 cm and 20 cm, preferably between 0 cm and 10 cm, and even more preferably between 0 cm and 5 cm. It is therefore understood that this distance D can be zero. By way of example, this distance is illustrated in Figures 5 to 8. The distance D can be taken between the free surface 50 of the storage fluid 5 in the tank and the median plane of withdrawal or injection of the storage fluid by the second injection and withdrawal system 111. In the following, it is assumed, for the sake of completeness, that the injection and withdrawal take place at the filling level 50.

[0098] Thus, the second injection and withdrawal system 111 makes it possible to monitor the variable storage fluid level 5 of the tank selected to be emptied or filled, so as to allow: - During the charging phase (illustrated for example in [Fig. 3]), a progressively colder flow of storage fluid is drawn off, at the level of the free surface of the decreasing fluid level in the draining tank. The temperature schedule is thus followed for the cooling of sterilizer 200. - During the discharge phase (illustrated for example in [Fig.4]), an increasingly hot flow of storage fluid 5 is injected, at the level of the increasing free surface of the storage fluid 5 in the filling tank. Thermal stratification is then maintained.

[0099] During the cooling phase of the sterilizer 200, i.e., the charging phase of the storage module 100 as illustrated in [Fig. 3], the storage fluid 5 returning from the heat exchanger 102 is injected into the storage module 100, controlling thermal stratification. This thermal stratification is made possible by the fact that the storage fluid 5 returning from the heat exchanger 102 during the cooling phase is increasingly cold and is injected through the lower part 110b of the selected reservoir to be filled.

[0100] The storage circuit 101 includes a first branch 104 originating from the heat exchanger 102 and supplying the thermal storage module 100 (stock-to). The first branch 104 is fluidly connected to an outlet of the heat exchanger 102 and to an inlet of the storage module 100. The storage circuit 101 includes a second branch 105 originating from the thermal storage module 100 and supplying the heat exchanger 102 (stock-from). The second branch 105 is fluidly connected to an outlet of the storage module 100 and to an inlet of the heat exchanger.

[0101] The storage circuit 101 is preferably configured to operate in a closed circuit. Note that it is possible to add storage fluid 5, for example via a top-up valve 103.

[0102] The storage module 100, and in particular the tanks 110, 120, 130, 140, are preferably connected in parallel to the storage circuit 101. Each tank 110, 120, 130, 140 can be connected to the first branch 104 and the second branch 105 respectively by a first line 11 and a second line 12. The first line 11 is fluidly connected to the first branch 104, ensuring the supply of storage fluid 5 to the tank. The second line 12 is fluidly connected to the second branch 105, ensuring the outlet of the storage fluid 5 from the tank.

[0103] Each line 11,12 advantageously includes a thermally controlled hydraulic isolation valve. The opening or closing of the isolation valve is controlled according to the temperature of the storage fluid, preferably measured at its sampling point (Tstock _nj0ou i, with n the number of the tank and 0 for a measurement of the storage fluid 5 passing through the first injection and withdrawal system 108 and 1 for a measurement of the storage fluid 5 passing through the second injection and withdrawal system 111), and a predefined temperature setpoint, preferably evaluated according to the temperature to be reached by the sterilization fluid at its outlet of the heat exchanger (TSTw,to) when it is heated or cooled respectively by a hot source or by a cold source, which may be the storage fluid 5.Isolation valves are designated Vstock "from" for the control valves of the outlet of the storage fluid from a tank n. They are advantageously arranged on the second lines 12. Isolation valves are designated Vstock n to for the control valves of the inlet of the storage fluid into a tank n. They are advantageously arranged on the first lines 11. These isolation valves vstock n fromOt / or Vstock "to" thus allow selection of the tank to be emptied and the tank to be filled, particularly according to their states and the phase of the sterilization cycle being operated. Advantageously, these isolation valves vstock n fromOt / or Vstock n. to are on / off valves, i.e., open / closed.

[0104] Each tank 110, 120, 130, 140 may further include two selector valves controlled by the injection and withdrawal system 108, 111 to be used. These valves are advantageously fluidically connected to, for example positioned on, a third line 13 forming a sub-branch common to the lines 11, 12. Thus, it is possible to select the first 108 or second 111 injection and withdrawal system, for injecting or withdrawing the storage fluid 5 for the circulation of the storage fluid 5 in the corresponding line 11, 12.

[0105] The Vstockn, if valve of each tank n can be fluidly connected to the first injection and withdrawal system 108 located in the lower part 110b of the tank. The Vstockn, Sv valve of each tank n can be fluidly connected to the second injection and withdrawal system 111. Advantageously, these selection valves Vstockn, ipet / or Vstockn, sv are on / off valves, i.e., open / closed. Preferably, during injection or withdrawal of the storage fluid 5 from a tank n, when one is open, the other is closed.

[0106] According to one example, the first Vstockn >1F and second Vstockn >Sv selection valves are positioned downstream of the first pipe 11 and upstream of the second pipe 12, in the direction of flow of the storage fluid, and preferably via the third pipe 13. The third pipe 13 is therefore positioned between the first Vstockn >1F and second Vstockn >Sv selection valves, and the first 11 and second pipe 12.

[0107] The recovery unit 10 advantageously includes a VSV-Q valve arranged on the storage circuit, preferably downstream of the flow meter 109. The VSV-Q valve is intended to ensure the variation of the flow rate of the storage fluid in the storage circuit. Note that the flow meter 109 may not be present in the recovery unit 10, particularly in an industrial version of the unit.

[0108] Following an example of this energy recovery unit providing an industrial-scale thermal storage solution, a single VSV-Q flow control valve can be used for both the storage circuit and the cooling water. This means that a single valve regulates the flow rate of the heat transfer fluid circulating in the heat exchanger 102 of the sterilizer 200, whether from the storage circuit or from a cooling water supply 302. This dual use of the VSV-Q flow control valve is possible because the storage circuit and the cooling water supply 302 are decoupled and do not operate simultaneously on the same sterilizer 200.The inherent advantage of sharing the VSV-Q flow control valve is the savings from purchasing an additional (and expensive) control valve, thus reducing the investment cost of the thermal storage solution.

[0109] Similarly, the flow meter 109 can be used both to measure the flow rate of water supplying the heat exchanger 102 from either the storage circuit or the cooling water inlet 302. According to this possibility, the storage circuit includes downstream of the pump 107 the flow meter 109, then a connection of a cooling water inlet branch 302 ensuring the cooling water inlet 302 and then the VSV-Q control valve.

[0110] The recovery unit according to the invention advantageously comprises thermal instrumentation including thermometers for measuring the temperature of the storage fluid at various points in the recovery unit. Preferably, the thermal instrumentation also includes thermometers for measuring the temperature of the sterilization fluid entering and exiting the heat exchanger 102 and returning to or flowing towards the sterilizer 200. In the figures, the thermometers of the thermal instrumentation are designated either Tstock for thermometers relating to the storage fluid 5 or TSTw for thermometers relating to the sterilization fluid.

[0111] Advantageously, to guarantee its autonomy, the thermal storage circuit 101 is equipped with its own pump 107 ensuring the circulation of the storage fluid. Advantageously, the recovery unit can operate with only one pump 107. and even in the case of pooling the recovery unit 10 with several sterilizers 200. Indeed, the storage circuit 101 operating in a closed circuit, all the extracted flow is reinjected.

[0112] According to one possibility, to maintain the operation of the pump 107 at its nominal speed, despite variations in the storage fluid flow rate, the storage circuit includes a bypass branch 106 providing a bypass routing of the storage fluid. Advantageously, the circulation of the storage fluid in the bypass branch 106 is regulated by the valve Vby flanking the pump 107, preferably at its terminals. According to another possibility, the pump 107 can be equipped with a frequency converter that can be used to control the flow rate of the storage fluid circulating in the storage circuit by varying the pump's rotational speed.

[0113] Given the potentially high temperature of the storage fluid charged into the tanks 110, 120, 130, 140, which may approach the evaporation temperature of the storage fluid, such as 100°C for water at atmospheric pressure, according to one example, the recovery unit advantageously includes a pressurization system 400 for the storage module 100. The pressurization module 400 is configured to pressurize the tanks 110, 120, 130, 140 so as to maintain the storage fluid, and in particular superheated water, in a liquid state.

[0114] To overcome the constraint of the variable level of tanks 110, 120, 130, 140, which could lead to tank depressurization during the discharge phase by withdrawal, the pressurization module 400 is configured to pressurize the free surface of the storage fluid 5 using, for example, a gas such as air or nitrogen. The pressurization module 400 is advantageously installed and connected to the upper part of each tank 110, 120, 130, 140 to maintain sufficient pressure, essential for keeping the storage fluid, and in particular the superheated water, in a liquid state.

[0115] The pressurization module 400 is configured to operate preferentially as a communicating vessel. To this end, the pressurization module 400 includes a gas circuit connecting all the tanks 110, 120, 130, and 140, preferably via their upper sections, so as to maintain a homogeneous pressure in each of them, regardless of their storage fluid level. To limit the ingestion of storage fluid from one tank to another via this circuit, the pressurization module 400 may include, according to a variant not shown, an automatic drain valve located between the top of each tank and the pressurizing gas circuit. Another example of a pressurization system 400 is illustrated in Figures 2 to 4, 9, and 10. The illustrated pressurization system 400 is more simplified than the one shown. Just before. In the figures, the illustrated pressurization system 400 does not show a rupture disc, which is an additional safety component fitted to the pressurization system. The pressurization system 400 is configured to be fitted to the illustrated 10 recovery units.

[0116] According to one embodiment, the recovery unit 10 according to the invention comprises a mass flow meter 109 (rhstock) arranged on the storage circuit 101, more preferably on the second branch 105 of the circuit and more preferably downstream of the pump 107. The flow meter 109 ensures the measurement of the flow rate of storage fluid circulating in the storage circuit 101 and intended to supply the heat exchanger 102. In this case, the flow rate of the storage fluid is advantageously regulated according to the temperature measurements at the terminals of the heat exchanger 102 so that the setpoint temperature of the sterilization fluid is reached at the outlet of the heat exchanger 102 (TSTw,to). According to another embodiment, the control of the flow rate of the storage fluid is freed from the use of a flow meter.This control method relies on evaluating the efficiency of the heat exchanger 102 based on temperature measurements at its terminals and the setpoint temperature that the sterilization fluid must reach at the heat exchanger outlet (TSTw, to). A correlation between the efficiency of the heat exchanger 102 and the flow rate of the storage fluid has been established. This relationship, which correlates the efficiency of the heat exchanger 102 with the flow rate of the storage fluid, is based on the fact that the very high and constant flow rate (for example, 265 m³ / h) of the sterilization fluid in the sterilization circuit 201 implies that the limiting thermal resistance is always located on the side of the storage circuit 101 when it is in use.It is therefore possible to control the flow rate of the storage fluid and thus the thermal power transferred, by evaluating the efficiency of the heat exchanger 102 from the temperatures measured at its terminals and the setpoint temperature that the sterilization fluid must reach at the outlet of the heat exchanger (TSTw,to)- .

[0117] According to an advantageous embodiment, the recovery unit comprises at least two isolation valves VstockM.lso of the storage circuit 101 with respect to the heat exchanger 102. The isolation valves VstockM.lso are arranged on the storage circuit 101, advantageously one on the first branch 104 and the other on the second branch 105. Preferably, the isolation valves VstockM.lso are arranged at the terminals of the heat exchanger. These valves are configured to ensure the isolation of the storage circuit 101 and thus stop the circulation of the storage fluid in the heat exchanger 102, in particular to allow the circulation in the heat exchanger 102 of a cold source or a hot source acting as a backup. of the storage fluid 5. Advantageously, these VstockM_lsos valves are on / off, open / closed valves.

[0118] Preferably, the VstoCkM isolation valves are robotized and controlled by a management module.

[0119] According to one embodiment, the recovery unit includes a thermal energy management module. The management module is configured to ensure optimal recovery of the thermal energy intended for at least one sterilizer 200. The management module preferentially controls the isolation valves of the tanks Vstock_from and VstoCk -to, as well as the isolation valves of the storage circuit 101 VstoCkM iso-. According to one possibility, the management module evaluates the efficiency of the heat exchanger 102 based on the temperatures measured at its terminals and the setpoint temperature that the sterilization fluid must reach at the outlet of the heat exchanger (TSTW>to). In this case, the management module advantageously controls a pump 107 equipped with a variable frequency drive, which can be used to control the flow rate of the storage fluid circulating in the storage circuit by varying the pump's rotational speed.According to another possibility, the management module controls the VSV-Q valve intended to modulate the flow rate of the storage fluid at the inlet of the sterilizer 200. The management module collects information from the recovery unit through various instruments, such as the flow rate of the storage fluid circulating via the flow meter 109, and / or the temperatures of the storage fluid and / or the sterilization fluid via the thermal instrumentation described above.

[0120] The control module is designed to maintain a set temperature to ensure the correct operation of sterilizer 200. A set temperature is predefined. Preferably, this set temperature is that of the sterilizing fluid at the outlet of the heat exchanger 102 (TSTW>to). Depending on one possibility, this set temperature varies according to the operating phase of sterilizer 200. The set temperature follows a scale that corresponds to the operation of sterilizer 200.

[0121] The management module thus controls the flow of storage fluid (rhstock) advantageously circulating in a closed loop in the storage circuit 101 by modulating the VSV-Q control valve.

[0122] Advantageously, the management module ensures the control of the isolation valves of the tanks and the selection valves of the first 108 or second 111 injection and withdrawal system, according to the temperature of the storage fluid contained in said tanks and the thermal energy requirements of the sterilizer 200. The management module can control the order of storage and destocking of the storage fluid from the tanks.

[0123] The sterilization device illustrated in Figures 2 to 4, 9, and 10 includes a common part shown on the right side of all the figures and described below. The sterilization device comprises a sterilizer 200 supplied with a sterilization fluid advantageously circulating in a closed loop in a sterilization circuit 201 between the heat exchanger 102 and the sterilizer 200. The sterilization circuit 201 advantageously includes a pump 202 and optionally a mass flow meter 203. The heat exchanger 102 includes an inlet 204 and an outlet 205 for the sterilization fluid and an inlet 206 and an outlet 207 for a hot or cold source, as required. In an advantageous configuration, the hot source is either steam from a heating means such as, for example, a boiler, or a storage fluid.Similarly, the cold source is either cooling water from a water network or the storage fluid.

[0124] The figures therefore illustrate a cooling water inlet 302, a steam inlet 301 connected to the inlet 206 of the heat exchanger 102 and a cooling water outlet 303 and a condensate outlet 304 connected to the outlet 207 of the heat exchanger 102.

[0125] Such a properly sized, designed, and operated energy recovery unit would allow for the recovery, under steady-state conditions, of approximately 30% of the thermal energy required for the heating phase and the thermal energy required to dissipate heat during the cooling phase of the sterilization process, by recovering and storing the waste heat extracted from the sterilizer 200 during the cooling phase of the preceding cycle. Such a solution could be profitable over very short periods, for example, less than 3-4 years, and particularly if, in this context, the sterilization process to which it is coupled performs a large number of cycles per day, for example, more than 5 cycles per day. Furthermore, profitability would be even greater since the energy recovery unit would allow for the recovery of a greater quantity of energy per cycle compared to existing solutions.

[0126] The energy recovery unit according to the invention makes it possible to recover a quantity of thermal energy between sterilization cycles, thereby reducing the quantities of steam and cooling water consumed, but also contributes to increasing the availability of utilities (steam, cooling water). Indeed, when autoclaves or sterilizers are heated or cooled by the energy recovery unit, they do not draw flow from the steam or cooling water networks, consequently increasing their capacity and availability for other autoclaves (sterilizers or equipment) not supplied by the energy recovery unit. This advantage will be particularly beneficial in installations that experience utility congestion problems, leading to Limit either the number of devices that can be powered in parallel, or the speed of temperature increases and decreases (ramps - following the schedule). Furthermore, in the case of installing additional autoclaves / sterilizers on existing networks, integrating a recovery unit could potentially limit, or even eliminate, the need for investment in supplementary heating and / or cooling systems to power them.

[0127] The invention relates to a method for recovering thermal energy by means of a recovery unit as described above. The recovery method advantageously comprises a discharge stage alternately with a charging stage.

[0128] The charging of the storage module 100 corresponds to the storage of the storage fluid that has recovered thermal energy at the heat exchanger 102. This charging stage of the storage module 100 corresponds to the cooling phase of the sterilizer 200. During this cooling phase, the sterilizer 200 and its contents are cooled by the circulation of the sterilization fluid, which is cooled at the heat exchanger 102 by heat exchange with a cold source, which can be cooling water or the storage fluid. In the case of a charging stage of the storage module 100, it is indeed the storage fluid that circulates in the heat exchanger 102 to exchange heat with the sterilization fluid to ensure the cooling of the sterilization fluid.

[0129] At the beginning of the charging stage, i.e., at the end of the discharging stage, the storage module 100 contains storage fluid, with the exception of the buffer volume, which advantageously corresponds to a reservoir 110, 120, 130, or 140 that is kept empty. The reservoir(s) containing the storage fluid are either fully or partially filled. Preferably, if the storage module 100 comprises more than two reservoirs 110, 120, 130, or 140, their levels are identical due to the principle of communicating vessels. Optimal energy recovery does not necessarily require filling the reservoirs to their maximum volume, with the exception of the buffer volume. This is particularly true at startup when the storage fluid initially contained in the reservoirs is close to ambient temperature.The storage fluid contained in each tank 110, 120, 130, 140 is advantageously at a nearly homogeneous temperature throughout the entire volume of the tank 110, 120, 130, 140.

[0130] The charging step, for example illustrated in Figures 3 and 9 according to two variants, comprises the withdrawal of the storage fluid 5 from a storage tank 110, 120, 130, 140, such as, for example, the second storage tank 120. The storage fluid 5 is withdrawn by the second storage fluid injection and withdrawal system 111, at the storage fluid fill level 50 in the tank 120 to be emptied. The withdrawal thus follows the thermal stratification of the storage fluid. 5 in the tank to be drained, from the hottest temperature to the coldest temperature. The storage fluid 5 is recovered by the storage circuit 101, more specifically the second branch 105, ensuring the circulation of the storage fluid towards the heat exchanger 102. In one example, valve Vstock2-fromest is open, while the other valves Vstock n fromument can be closed. Valve Vstock2 sv is then open, while valve Vstock2 iF is closed.

[0131] Sampling can begin with reservoir 110, 120, 130, or 140, where the storage fluid has the highest temperature. Sampling continues with decreasing temperatures of the storage fluid, from hottest to coldest. This improves monitoring of the decreasing temperature curve for cooling sterilizer 200.

[0132] The charging step advantageously comprises simultaneously injecting the storage fluid 5 into a storage tank 110, 120, 130, 140, preferably different from the storage tank 110, 120, 130, 140 from which the storage fluid is withdrawn, and for example, the first storage tank 110. The storage fluid is injected into the buffer volume. Preferably, the tank 110, 120, 130, 140 intended to receive the storage fluid corresponds to the tank forming the buffer volume. The tank 110, 120, 130, 140 intended to receive the storage fluid is advantageously empty. The storage fluid is injected into the lower part 110b of tank 110 by the first injection and withdrawal system 108.The storage fluid 5 arrives increasingly cold, allowing for thermal stratification by maintaining the warmest storage fluid from the initial cooling of sterilizer 200 at the top and the coldest injected storage fluid 5 at the bottom. For example, when filling the first tank 110, valve VstoCki-to is open, while the other valves Vstockn can be closed. Valve Vstocki iF is then open, while valve Vstocki sv is closed.

[0133] The discharge of the storage module 100 corresponds to the release of the storage fluid, transferring its thermal energy to the heat exchanger 102. This discharge step of the storage module 100 corresponds to the heating phase of the sterilizer 200. During this heating phase, the sterilizer 200 and its contents are heated by the circulation of the sterilization fluid, which is heated in the heat exchanger 102 by exchanging heat with a hot source, which can be steam or the storage fluid. In the case of a discharge step of the storage module 100, it is indeed the storage fluid that circulates in the heat exchanger 102 to exchange heat with the sterilization fluid to ensure its heating.

[0134] At the beginning of the discharge stage, i.e., at the end of the charging stage, the tanks contain storage fluid, with the exception of the buffer volume, advantageously corresponding to a tank 110, 120, 130, or 140, which is kept empty. The tanks 110, 120, 130, and 140 containing storage fluid are either fully or partially filled. Preferably, if the storage module 100 comprises more than two tanks 110, 120, 130, or 140, their levels are identical, due to the communicating vessel principle. The storage fluid contained in each tank is advantageously temperature stratified.

[0135] The discharge of the storage module 100 is advantageously carried out according to an operating procedure that limits the alteration of the thermal stratification established in the previously charged tanks 110, 120, 130, 140, so as not to degrade the thermal energy contained in each of them. Unlike the charging process, during discharge, for example illustrated in Figures 4 and 10 according to two variants, the filled tanks 110, 120, 130, 140 comprising the storage module 100 are discharged to supply the heat exchanger 102 coupled to the sterilizer 200, starting with the one containing storage fluid at the lowest temperature and then proceeding in ascending order of temperature up to the tank 110, 120, 130, 140 storing storage fluid at the highest temperature.Advantageously, tanks 110, 120, 130, 140 containing a stratified storage fluid at a higher temperature are reserved for the end of the discharge when the heating of sterilizer 200 requires increasingly higher sterilization fluid temperatures.

[0136] The discharge step includes withdrawing the storage fluid from a storage tank 110, 120, 130, 140, such as, for example, the first storage tank 110. The storage fluid 5 is drawn from the lower part 110b by the first storage fluid injection and withdrawal system 108. The storage fluid from tank 110, 120, 130, 140 is temperature stratified and is thus recovered from coldest to warmest by the first injection and withdrawal system 108. The storage fluid 5 is recovered by the storage circuit 101, more precisely by the second branch 105 towards the heat exchanger 102. In one example, the Vstocki_from valve is open, while the other Vstockn_from valves can be closed. The Vstocki4Fest valve is then open, while the Vstocki svest valve is closed.

[0137] During the discharge stage, if several tanks are filled with storage fluid, the tank 110, 120, 130, 140 emptied first is the one with the lowest storage fluid temperature. The fluid is drawn successively from the tanks in ascending order of temperature. The storage fluid with the highest temperature is reserved for the end of the discharge process. where heating the sterilizer 200 requires increasingly higher sterilization fluid temperatures.

[0138] The discharge step advantageously includes simultaneously injecting the storage fluid into a storage tank 110, 120, 130, 140, preferably different from the storage tank from which the storage fluid is withdrawn, and for example, the second storage tank 120. The storage fluid is injected into the buffer volume. Preferably, the tank 110, 120, 130, 140 intended to receive the storage fluid corresponds to the tank 110, 120, 130, 140 forming the buffer volume. The tank intended to receive the storage fluid is advantageously empty.

[0139] The storage fluid 5 is advantageously injected by the second storage fluid injection and withdrawal system 111 at the storage fluid 5 filling level 50 in the tank to be filled. The injection of the storage fluid 5, which becomes increasingly hot during discharge, can therefore be timed to follow the natural thermal stratification of the storage fluid 5 within the tank. This optimizes the thermal stratification in the tank, thereby optimizing the reuse of the stored thermal energy for the subsequent filling phase. For example, when filling the second tank 120, valve Vstock2-to is open, while the other valves Vstockn can be closed. Valve VstOck2 sv is then open, while valve Vstock2-iF is closed.

[0140] Example of load of storage module 100 of the recovery unit.

[0141] As illustrated in Figures 3 and 9 for example, the module charging step Storage fluid 100 is loaded during the sterilizer's cooling phase. At the beginning of the loading stage of storage fluid 100, the four tanks 110, 120, 130, and 140 can each contain storage fluid at a different temperature, either homogeneously or stratified. As illustrated, tank 140 contains storage fluid at the highest homogeneous temperature (relative to the other tanks), while tank 130 contains storage fluid at the lowest homogeneous temperature. For example, tank 130 is at a nearly homogeneous temperature of 45°C. Tank 140 is at a nearly homogeneous temperature of 85°C. Tanks 110 and 120 can be temperature stratified. The average temperature of tank 120 can be lower than the average temperature of tank 110.

[0142] The charging of the storage module 100 can begin with a step of drawing off the storage fluid from a tank having the highest temperature. This can be the hottest tank 140 or directly the stratified tank 120 in temperature, according to the agreement between the temperature of the storage fluid in each tank and the expected temperature setpoint.

[0143] The withdrawal process begins with a flow of storage fluid necessary to ensure the cooling of the sterilizer 200 according to a predefined temperature setpoint. Simultaneously with the withdrawal step, the injection step begins. This flow of storage fluid, which is heated during its passage through the heat exchanger 102 coupled to the sterilizer 200, is then injected into the buffer volume, for example, the tank 110. The tank 110 is filled from its lower part, advantageously by the injection and withdrawal system 108, and preferably, if present, by a system that distributes and evens out the flow over the entire hydraulic cross-section of the tank.The bottom-filling system of the storage tank allows for temperature stratification of the injected storage fluid. The hottest storage fluid, resulting from the initial cooling of sterilizer 200, remains in the upper portion, while the coldest storage fluid is advantageously injected until tank 110 is completely filled. When tank 120 is empty or its internal temperature is no longer sufficient to cool sterilizer 200 at the maximum permissible flow rate in the storage circuit 101, another tank containing a storage fluid at a lower temperature than the storage fluid in tanks 120 and 110 is used. In Figures 3 and 9, for example, tank 130 would then take over.If tank 110 is full, the heated storage fluid is injected into the buffer volume, i.e., advantageously the empty tank 120, using the same procedure as for filling tank 110, so as to control thermal stratification of the storage fluid filling the tank. The final stage of charging storage module 100 is completed by temperature-stratified refilling of tank 110, drawing from tank 130, which is advantageously initially at a homogeneous temperature. During the charging phase of storage module 100, the selection of tanks 110, 120, 130, and 140 to be filled and the tanks to be supplied is carried out via the tank isolation valves, which are advantageously controllable by a management module.When the entire storage module 100 is loaded or when its state no longer allows the cooling of the sterilizer 200 to be ensured, the isolation valves of the storage circuit 101 VstockjM isolate the storage circuit 101 from the heat exchanger 102 coupled to the sterilizer 200, before the network of another cold source such as cooling water takes over via the inlet 302.

[0144] Advantageously, the withdrawal step in the tanks 110, 120, 130, 140, initially at a homogeneous or different average temperature, is always preferably carried out starting with the one that is at the highest temperature and then The process continues in descending order until the reservoir with the lowest temperature is reached. If the homogeneous or average internal temperature of the discharged reservoir (110, 120, 130, 140) is too high to ensure the cooling of the sterilizer (200), the next reservoir in descending order of temperature takes over.

[0145] At the end of the charging stage, at least one tank 110 can be filled with temperature-stratified storage fluid. For example, all three tanks 110, 130, and 140 can be filled with temperature-stratified storage fluid. For instance, tank 130 contains storage fluid with a temperature ranging from 50°C to 70°C from bottom to top, tank 110 contains storage fluid with a temperature ranging from 70°C to 90°C from bottom to top, and tank 140 contains storage fluid with a temperature ranging from 90°C to 110°C from bottom to top. These conditions correspond to an optimal operating case that has led to the complete discharge of each of the initially charged tanks. In a less favorable case, the temperature of the storage fluid in one or more of the tanks does not allow for their complete discharge.The reservoir used as a buffer for the next discharge will not initially be completely empty. This mode can be described as a degraded mode.

[0146] Example of discharging storage module 100:

[0147] As illustrated in Figures 4 and 10, for example, the discharge step of the storage module 100 takes place during the heating phase of the sterilizer 200. For instance, the temperature-stratified tank 110 can be discharged, provided that the temperature of the storage fluid drawn from its lower part is sufficient to meet the set temperature requirement for the sterilizing fluid at the outlet of the sterilizer 200, Tstw>to. Otherwise, discharge begins with the next tank that meets this temperature requirement, in ascending order of temperature. Assuming that the temperature requirement for tank 110 is met, the storage fluid feeds the heat exchanger 102 before being injected, cooled, into the buffer volume, i.e., advantageously an empty tank, in this case tank 120, which can be initially empty.The injection of the cooled storage fluid into tank 120 is carried out by the second injection and withdrawal system 111. Preferably, if present, this system distributes and evens out the flow rate across the entire hydraulic section of the tank. During this discharge phase of the storage module 100, the storage fluid injected into the tanks arrives increasingly hot. The use of the second injection and withdrawal system allows for monitoring the natural stratification of the storage fluid 5 in tank 120. As soon as tank 110 is completely emptied, or following the premature cessation of its withdrawal to maintain the set temperature of the sterilizing fluid sent to the sterilizer 200, tank 140 can... take over. The flow of storage fluid drawn from tank 110 and cooled after passing through the heat exchanger 102 then feeds tank 120. The operating procedure then follows during this phase of utilizing the stored thermal energy until the discharge, if possible, of tank 140 which contains a volume of stratified or non-stratified storage fluid at the highest temperature level.

[0148] Note that other variants can be considered. The recovery unit 10 may include a pump equipped with a variable frequency drive (VFD) which can be used to control the flow rate of the storage fluid circulating in the storage circuit by varying the pump's rotational speed. The recovery unit includes a PID control module connecting the temperature sensor Tstock from i, the valves VstockM, and optionally the water make-up. The flow rate of the heat transfer fluid 5 circulating in the recovery unit 10 is regulated by acting on the pump's variable frequency drive, which is controlled by the PID based on the temperature measurement Tstw > to. The flow rate measurement from the flow meter can also be taken into account for PID control.According to another example, the control instruction could, for example, be to act on the speed of the pump to increase the flow produced, in order to satisfy the setpoint on the measured temperature T STw.to, without necessarily needing to measure the flow rate.

[0149] The recovery unit may include a pump and a flow meter. The recovery unit may include a VSV-Q valve for flow regulation, advantageously arranged upstream of the flow meter and downstream of the pump. The recovery unit includes a PID control module connecting the pump, the VstoCkM iso valve, the flow meter, and optionally the water make-up. The flow rate of the storage fluid circulating in the recovery unit is regulated by the VSV-Q control valve, which is controlled by the PID for acquiring the temperature measurement TSTw. The flow measurement by the flow meter 109 may also be taken into account for PID control. Here again, according to another example, the control setpoint may, for example, be to adjust the pump speed to increase the output flow rate in order to satisfy the setpoint for the measured temperature Tstw, without necessarily needing to measure the flow rate.Flow rate is a parameter that can be controlled by the PID controller, and not necessarily a setpoint.

[0150] The sterilization device includes a recovery unit which may include a plurality of heat exchangers 102, for example three heat exchangers 102, each respectively associated with a sterilizer 200. The three heat exchangers 102 can be arranged in parallel, on the second branch 105 and on the first branch 104.

[0151] The second injection and withdrawal system 111 is now described in more detail with reference to Figures 5 to 8 and 11. It is considered, for the sake of completeness, that this system 111 is carried by the tank 110. This can of course be applied to each tank comprising the second injection and withdrawal system 111.

[0152] In order to adapt the injection or withdrawal of the storage fluid 5 to the filling level 50, the second injection and withdrawal system 111 includes a body 1110 movable along the vertical direction z within the tank to be emptied or filled. As illustrated, for example, in Figures 5 to 8, the body 1110 is configured to have a height H1 along the vertical direction z, the height H1 varying according to the filling level 50 of the storage fluid 5.

[0153] The body 1110 can more particularly be configured to contract or extend along a principal extension direction substantially parallel to the vertical direction z, and preferably in a telescopic manner. The body 1110 can therefore move between a retracted configuration and a maximum extended configuration, passing through several extended configurations depending on the filling level 50. Preferably, the body 1110 is only translationally mobile between its retracted configuration and its extended configurations. Preferably, the extension direction of the body 1110 is centered on the central longitudinal axis of the tank, parallel to the vertical direction z.

[0154] According to one example, the body 1110 comprises coaxial telescopic tubes 1110a, configured to slide telescopically between each other to move the body 1110 between its retracted and extended configurations.

[0155] According to one example, and as illustrated by Figures 5 and 8, the body 110 has an increasing internal hydraulic cross-section S from the point of connection to the fluidic circuit 101 (smallest cross-section) to the injection and withdrawal module 1111 (largest cross-section). The internal hydraulic cross-section S is perpendicular to the main direction of deployment of the body 1110, and therefore, for example, the cross-section S is substantially horizontal. This arrangement allows the flow velocity of the storage fluid 5 to be gradually reduced up to the point of hydraulic injection or withdrawal, which is more favorable for controlling thermal stratification within the reservoir.For this purpose, the coaxial tubes 1110a may have at least one internal dimension, for example a diameter, increasing along the body 1110 from the coaxial tube on the side of the connection point to the fluidic circuit 101, of the smallest dimension, to the coaxial tube on the side of the injection and withdrawal module 1111, of the largest dimension.

[0156] As an alternative to coaxial tubes, the body 1110 may be provided to include a flexible, preferably retractable, tube.

[0157] According to an example illustrated by Figures 5 and 6, the second injection and withdrawal system 111 is fluidically connected to the fluidic circuit 101 via the upper part 110a of the tank 110. In this example, the retracted configuration corresponds to the maximum filling of the tank 110, which can then be full or partially filled, as illustrated in [Fig. 6], the body then having a height H2. [Fig. 5] illustrates a deployed configuration in which H1>H2, during the filling or withdrawal of the tank 110. Preferably, the maximum deployed configuration corresponds to the minimum filling of the tank 110, which can then be empty or partially filled. If present, the connection of the pressurization module 400 is preferably also positioned in the upper part 110a of the tank 110, near the hydraulic connection with the body 1110.

[0158] According to an alternative example illustrated in Figures 7 and 8, the second injection and withdrawal system 111 is fluidically connected to the fluidic circuit 101 via the lower part 110b of the reservoir 110. This, however, implies the presence of an element that can be a thermal conductor within the temperature-stratified water volume. According to this example, the retracted configuration corresponds to the minimum filling of the reservoir 110, which can then be empty or partially filled, as illustrated in [Fig. 7], with the body 1110 then having a height H2. [Fig. 8] illustrates an extended configuration in which H1>H2, during the filling or withdrawal of the reservoir 110. Preferably, the maximum extended configuration corresponds to the maximum filling of the reservoir 110, which can then be full or partially filled.The connection of the first injection and withdrawal system 108 is then also located in the lower part 110b of the tank 110, near the hydraulic connection with the body 1110. For example, the first injection and withdrawal system 108 is arranged radially around the hydraulic connection with the body 1110.

[0159] The injection and withdrawal module 1111 of the storage fluid 5 is fluidly connected to the body 1110. During an injection, the storage fluid 5 therefore flows into the body 1110 to be injected into the reservoir 110 by the injection and withdrawal module 1111. During a withdrawal, the storage fluid 5 is taken up by the injection and withdrawal module 1111 and then flows into the body 1110 to be circulated in the storage circuit 101.

[0160] As illustrated in Figures 5 to 8, the injection and withdrawal module 1111 may include a flotation device 1112. The flotation device 1112 allows for passive monitoring of the fill level 50 of the storage fluid 5 contained in the tank 110. The displacement along the vertical direction z of the flotation device 1112 as a function of the fill level 50 can induce, and preferably on its own, the contraction or expansion of the body 1110. The The flotation device thus ensures that the hydraulic injection or withdrawal takes place just below or at the level of the free surface of the storage fluid 5 contained in the tank 110.

[0161] By way of example, for the first injection and withdrawal system 108, the storage module 100 includes a system for homogenizing and distributing the flow rate of the injected storage fluid throughout the hydraulic cross-section of the tanks 110, 120, 130, 140. For example, a system for homogenizing and distributing the flow rate of the storage fluid may include advantageously sized devices designed to uniformly distribute the flow rate of the storage fluid injected into and withdrawn from the tank over a larger hydraulic cross-section so as to reduce its flow velocity within the tank. Indeed, the higher the flow velocity, the greater the hydraulic mixing it will generate, which is very detrimental to the formation and maintenance of thermal stratification within the storage volume.These devices include, for example, hydraulic deflectors whose shape can be designed to ensure proper orientation and distribution of the flow within the tank while reducing its flow velocity.

[0162] Such systems may be provided as an alternative or complement to the second injection and withdrawal system 111. In order to obtain a more homogeneous distribution of the velocity profile of the injected or withdrawn storage fluid flow rate 5, the aim is to limit the temperature mixing phenomenon between the volume of the storage fluid 5 contained in the reservoir at the injection or withdrawal point and the injected or withdrawn storage fluid flow rate. For this purpose, the injection and withdrawal module can be configured to withdraw and inject the storage fluid radially in a plane substantially parallel to, and preferably coinciding with, the plane of the free surface of the storage fluid 5, and for example in a plane substantially perpendicular to the deployment direction of the body 1110, and therefore preferably in a substantially horizontal plane.The term "radial" can be understood in relation to the cross-section in the (x,y) plane of a tank, for example, one of cylindrical shape.

[0163] For this purpose, the injection and withdrawal module 1111 can comprise at least two plates 1111a, 1111c, for example flat or pavilion-shaped. The transverse dimension, for example the diameter, and / or the inter-plate spacing D can be advantageously dimensioned to optimize the formation and maintenance of thermal stratification. As an indication, for a storage tank of a few m³, considering an injection or withdrawal point based on a double-plate design, the characteristic dimensions could be on the order of 200 mm for the plate diameter and on the order of ten millimeters for the inter-plate spacing D. Of course, these characteristic dimensions are illustrative because they depend specifically on the hydraulic (flow rate) and thermal conditions of the storage fluid (temperature of the contained fluid and of the injected or withdrawn fluid) as well as the dimensions of the reservoir, and this in relation to the most representative dimensionless numbers in this physics such as the Richardson number and the Froude number.

[0164] Figures 9 and 10 represent P&ID diagrams respectively in charge and discharge of the storage module 100, according to the variant in which the second injection and withdrawal system 111 is fluidly connected to the circuit 101 by the lower part 110b of the tanks 110, 120, 130, 140.

[0165] By way of example, and particularly when the body 1110 comprises coaxial tubes sliding telescopically relative to each other, the body 1110 may include a rotation-locking device 1110b. The locking device 1110b may be configured to prevent the relative rotation of the coaxial tubes, and thus to lock the coaxial tubes in rotation. The body 1110 is therefore mobile only in its deployment direction, and preferably in the vertical direction z. For this purpose, as illustrated in [Fig. 111], this rotation-locking guiding device 1110b may include profiled elements, for example, needles, facilitating the translational guidance of the coaxial tubes 1110a, ensuring their centering and preventing their rotation. The coaxial tubes may have complementary grooves 1110ab to house these elements. The grooves are preferably formed longitudinally on the outer wall of the inner tube and on the inner wall of the outer tube.The grooves of two coaxial tubes are positioned opposite each other. The needle / groove pairs are preferably distributed radially at the vertices of a polygon centered on the deployment axis of the body 1110. The locking device 1110b preferably comprises at least three needles. Stops at the ends of the grooves 1110ab or the coaxial tubes 1110a may be added to prevent the coaxial tube assembly from separating or the needles from coming out of their housing.

[0166] Following another example, a coaxial tube, for example one coaxial tube out of two, and in particular the inner tube, may be provided with a protrusion along the longitudinal axis on its outer wall, while the tube opposite, in this case the outer tube, may be provided with a groove along the longitudinal axis on its inner wall, dimensioned to accommodate the protrusion of the inner tube.

[0167] The invention is not limited to the embodiments described above and extends to all embodiments covered by the invention. The present invention is not limited to the examples described above. Many other embodiments are possible, for example by combining features described above, without departing from the scope of the invention.

[0168] For example, as an alternative to a passive flotation device, an active electrical system, operating for example with a worm screw, can be provided to modify the height of the body of the second injection and withdrawal system.

[0169] The loading and unloading steps are illustrated above with reference to certain tanks that are being drawn off or filled. The tanks are designated for illustrative purposes of the process. Another order of filling and / or drawing off is possible, particularly depending on the temperature schedule to be observed and the temperature of the storage fluid, stratified or not, in each tank.

[0170] It can also be provided that the storage fluid is temperature stratified in all the tanks of the storage module.

[0171] LIST OF REFERENCES 11. First driving 12. Second driving 13. Third driving 100. Storage Module 101. Storage circuit 102. Heat exchanger 103. Water refill 104. First branch 105. Second branch 106. Branch off 107. Pump 108. First injection and withdrawal system 109. Flow meter 110. Reservoir 110a. Upper part 110b. Lower part 111. Second injection and withdrawal system 1110. Body 1110a. Coaxial telescopic tubes 11 lOab. Groove 1110b. Rotation locking system 1111. Injection and withdrawal module 1111a. Plate 1111b. Plate 1111c. Inter-plate spacing 1112. Flotation device 120. Reservoir 130. Reservoir 140. Reservoir 200. Sterilizer 201. Sterilization circuit 202. Pump 203. Flow meter 204. Inlet of the sterilizing fluid into the exchanger 102 205. Sterilization fluid outlet from exchanger 102 206. Entrance to a hot or cold spring 207. Outlet of a hot or cold spring 301. Steam arrival 302. Cooling water inlet 303. Cooling water return 304. Condensate return 400. Pressurization Module 5. Storage fluid 50. Fill level

Claims

1. Demands Valuation unit (10) comprising: • a heat exchanger (102), • a thermal energy storage module (100) configured to receive a storage fluid (5), the storage module comprising at least two tanks (110, 120) each intended to receive the storage fluid (5) and each comprising a first injection and withdrawal system (108) for the storage fluid arranged in the lower part (110b) of said tank (110, 120), the first injection and withdrawal system (108) being configured to draw and inject the storage fluid (5) into the lower part of said tank (110, 120), the storage module (100) further comprising an empty volume called a buffer volume, the storage fluid intended to be stored in the storage module (100) representing a volume less than the volume of the storage module (100) so as to maintain the buffer volume, • a thermal storage circuit (101) configured to fluidly connect the storage module (100) and the heat exchanger (102) to ensure the circulation of the storage fluid (5), characterized in that the at least two tanks (110, 120) are intended to have a filling level (50) of storage fluid, separating a filled sub-volume and an empty sub-volume, and in that the at least two tanks (110, 120) each comprise a second injection and withdrawal system (111) for the storage fluid (5), each second injection and withdrawal system (111) comprising: • a body (1110) configured so as to be at least partially mobile along a vertical direction (z) in said reservoir (110, 120), and • an injection and withdrawal module (1111) for the storage fluid (5) fluidically connected to the body (1110), so as to draw and inject the storage fluid (5) at a variable height depending on the level of filling with storage fluid of said tank (110, 120).

2. Valorization unit (10) according to the preceding claim, wherein the body (1110) of at least one, and preferably of each, second injection and withdrawal system (111) has a deployed configuration and a plurality of retracted configurations, so as to modify the length of the body (1110) along the vertical direction z as a function of the filling level (50) in storage fluid (5).

3. Valorization unit (10) according to the preceding claim, wherein the body (1110) of at least one, and preferably of each, second injection and withdrawal system (111) is telescopic and slides along a main deployment direction of the body (1110), the body (1110) having an internal hydraulic section (S), taken substantially perpendicular to the main deployment direction of the body, increasing along the main deployment direction towards the injection and withdrawal module (1111).

4. Valorization unit (10) according to the preceding claim, wherein the body (1110) of said second injection and withdrawal system (111) comprises: • a set of coaxial telescopic tubes (1110a) configured together to slide along the main deployment direction of the body (1110), and • a rotation locking device (1110b), around the main deployment direction of the body, of the telescopic tubes (1110a) relative to each other.

5. Valorization unit (10) according to any one of the preceding claims, wherein the at least two tanks (110, 120) have an upper part (110a), and wherein the body (1110) of at least one, and preferably of each, second injection and withdrawal system (111) extends from the upper part (110a) of said tank (110, 120) so as to extend mainly into the empty sub-volume.

6. Valuation unit (10) according to any one of the preceding claims, wherein each second injection and withdrawal (111) is configured to draw and inject the storage fluid (5), by the injection and withdrawal module (1111), at a distance (D) extending into the filled sub-volume from the filling level (50), the distance (D) being between 0 cm and 20 cm.

7. Valorization unit (10) according to any one of the preceding claims, wherein the injection and withdrawal module (1111) of at least one, and preferably of each, second injection and withdrawal system (111) comprises a flotation device (1112).

8. Valorization unit (10) according to any one of the preceding claims, wherein the injection and withdrawal module (1111) of at least one, and preferably of each, second injection and withdrawal system (111) is configured to radially inject or withdraw the storage fluid (5).

9. Valorization unit (10) according to any one of the preceding claims, wherein said injection and withdrawal module (1111) comprises at least two plates (1111a, 1111b) at least partially superimposed along the vertical direction z, the at least two plates (1111a, 1111b) delimiting a gap (1111c) having rotational symmetry about the vertical direction z and permitting the injection and withdrawal of the storage fluid (5).

10. Valorization unit (10) according to any one of the preceding claims, further comprising, for each of the at least two tanks (110, 120), a first selection valve (Vstockn >IF) fluidly connected to the first injection and withdrawal system (108), a second selection valve (Vstockn ,sv) fluidly connected to the second injection and withdrawal system (111), the first and second selection valves being configured to select one of the first (108) and second (111) injection systems to inject or withdraw the storage fluid (5).

11. A recovery unit (10) according to the preceding claim, wherein the thermal storage circuit (101) comprises, for each of the at least two tanks (110, 120), a first pipe (11) for conveying the storage fluid (5) to the inlet of said tank (110, 120) and a second pipe (12) for conveying the storage fluid (5) to the outlet of said tank (110, 120), and a third pipe (13) forming a common sub-branch of the first (11) and second (12) pipes, and positioned downstream of the first pipe (11) and upstream of the second pipe (12) in the direction of flow of the storage fluid (5), the first (Vstockn >IF) and second (Vstockn , sv) selection valves being fluidly connected to the third pipe (13).

12. Sterilization device comprising a sterilizer (200) and a recovery unit (10) according to any one of the preceding claims.

13. Sterilization device according to the preceding claim comprising a cold source inlet (302) different from the storage fluid and a hot source inlet (301) different from the storage fluid (5).

14. A method for recovering thermal energy by a recovery unit (10) according to any one of claims 1 to 11, the recovery unit (10) receiving a storage fluid (5), the method comprising a charging step of the storage module (100) comprising: • the withdrawal of the storage fluid (5) by the second injection and withdrawal system (111) from one of the at least two storage tanks (110, 120), to a height in said tank depending on the filling level (50) in storage fluid (5), for the circulation of the storage fluid (5) in the storage circuit (101) in order to exchange thermal energy in the heat exchanger (102), • the injection of the storage fluid (5) into the buffer volume.

15. A method according to the preceding claim, wherein during the withdrawal, the reservoir (110, 120, 130, 140) from which the storage fluid (5) is withdrawn comprises the storage fluid (5) exhibiting temperature stratification.

16. A method according to any one of the two preceding claims, wherein during the injection step, the buffer volume is a reservoir (110, 120) distinct from the storage reservoir (110, 120) from which the storage fluid (5) is drawn, and the storage fluid (5) is injected into the lower part (110b) of the reservoir (110, 120) by the first injection and withdrawal system (108) and arrives increasingly cold, ensuring thermal stratification of the storage fluid (5) in the buffer volume.

17. A method for recovering thermal energy by a recovery unit (10) according to any one of claims 1 to 11, the recovery unit (10) receiving a storage fluid (5), the method comprising a step of discharging the storage fluid (5) comprising: • the withdrawal, by the first injection and withdrawal system (108), of the storage fluid in the lower part of a storage tank (110, 120), from among the at least two storage tanks (110, 120) for the circulation of the storage fluid in the storage circuit (101) in order to exchange thermal energy in the heat exchanger (102), • the injection of the storage fluid into the buffer volume.

18. A method for recovering thermal energy according to claim 17 in which, during the withdrawal step, the reservoir (110, 120) from which the storage fluid is withdrawn comprises the temperature-stratified storage fluid, the withdrawal being carried out in the lower part, the withdrawal begins with the coldest storage fluid and proceeds to the hottest.

19. A method according to any one of the two preceding claims wherein during the injection step, the buffer volume is a reservoir (110, 120) different from the storage reservoir (110, 120) from which the storage fluid is withdrawn, the storage fluid is injected by the second injection and withdrawal system (111) from said storage reservoir, to a height in said reservoir depending on the level of filling in storage fluid, and arrives increasingly hot and is thermally stratified as the storage fluid is injected into said reservoir.

20. A method according to any one of the six preceding claims, wherein the valorization unit (10) further comprises, for each of the at least two reservoirs (110, 120), a first selection valve (Vstockn, if) fluidly connected to the first injection and withdrawal system (108), and a second selection valve (Vstockn sv) fluidly connected to the second injection and withdrawal system. of decantation (111), the process further comprising a selection of the injection and decantation system to be used, from among the first (108) and second (111) injection and decantation systems.

Images