FR3151649A1 - Installation and method for supplying industrial steam with double heat recovery stage - Google Patents

Abstract

Plant (100) and method for supplying industrial steam. The plant (100) comprises a first stage (6) for recovering fatal heat for increasing the temperature of a first heat transfer fluid used for superheating an outlet fluid using a superheating device (8) and a second stage (7) for recovering fatal heat for increasing the temperature of a second heat transfer fluid used for increasing the temperature of the first heat transfer fluid and/or the outlet fluid. Abstract: Fig. 1

Description

Installation and method for supplying industrial steam with double heat recovery stage

The invention relates to the field of industrial steam production, that is to say steam used in industrial processes.

The invention is of particular interest, in no way limiting, for providing steam to a process for producing hydrogen by electrolysis of water vapor, also called “high temperature electrolysis”, where the water vapor typically requires a temperature between 600°C and 850°C.

State of the prior art

Industrial steam is usually produced using generators using electricity or fossil fuels as the energy source.

There is a need to reduce the ecological impact of industrial steam generators.

• un dispositif de récupération de chaleur ayant :
  • un premier étage configuré pour pouvoir transférer de la chaleur d’un premier fluide circulant dans un premier circuit à un deuxième fluide caloporteur circulant dans un deuxième circuit afin d’augmenter la température de ce deuxième fluide, et
  • un deuxième étage configuré pour pouvoir transférer de la chaleur du premier fluide circulant dans le premier circuit à un troisième fluide caloporteur circulant dans un troisième circuit afin d’augmenter la température de ce troisième fluide,
• un dispositif de surchauffe configuré pour pouvoir transférer de la chaleur du deuxième fluide circulant dans le deuxième circuit à un flux gazeux d’un quatrième fluide circulant dans un quatrième circuit afin d’augmenter la température de ce flux gazeux,
• un dispositif de valorisation comprenant au moins un échangeur de chaleur configuré pour pouvoir transférer de la chaleur du troisième fluide circulant dans le troisième circuit :
  • au deuxième fluide circulant dans le deuxième circuit afin d’augmenter la température du deuxième fluide en amont du dispositif de surchauffe relativement à un sens d’écoulement du deuxième fluide dans le deuxième circuit, et/ou
  • audit flux gazeux du quatrième fluide circulant dans le quatrième circuit afin d’augmenter la température de ce flux gazeux.

For this purpose, the invention relates to a steam supply installation, comprising:

• a heat recovery device having:
  • a first stage configured to be able to transfer heat from a first fluid circulating in a first circuit to a second heat transfer fluid circulating in a second circuit in order to increase the temperature of this second fluid, and
  • a second stage configured to be able to transfer heat from the first fluid circulating in the first circuit to a third heat transfer fluid circulating in a third circuit in order to increase the temperature of this third fluid,
• a superheating device configured to be able to transfer heat from the second fluid circulating in the second circuit to a gas flow of a fourth fluid circulating in a fourth circuit in order to increase the temperature of this gas flow,
• a recovery device comprising at least one heat exchanger configured to be able to transfer heat from the third fluid circulating in the third circuit:
  • to the second fluid circulating in the second circuit in order to increase the temperature of the second fluid upstream of the superheating device relative to a flow direction of the second fluid in the second circuit, and/or
  • said gas flow of the fourth fluid circulating in the fourth circuit in order to increase the temperature of this gas flow.

The first fluid, also called “input fluid”, can be in a gaseous and/or liquid state, including for example a combustion gas, air or even water vapor.

Without limitation, the input fluid contains waste heat which can come from many types of industries or processes, for example from a cement plant, a steel plant, a plant in the chemical sector or from various processes generating exothermic reactions.

The fourth fluid, also called the “output fluid,” preferably comprises water, so that the steam supplied by the installation may be water vapor.

The second stage of the heat recovery device makes it possible to recover, using said recovery device, heat not recovered at the level of the first stage. The recovery device in fact makes it possible to transfer part of this heat directly to the outlet fluid and/or to the heat transfer fluid circulating in the second circuit so as to increase the quantity of heat thus transferred to the outlet fluid by the superheating device.

The invention makes it possible to produce steam using a fatal heat source, by optimizing heat recovery and its valorization, and by increasing the quantity of steam produced.

Preferably, the heat recovery device comprises a first heat exchanger forming said first stage and a second heat exchanger forming said second stage.

In one embodiment, the second heat exchanger of the heat recovery device is downstream of the first heat exchanger of the heat recovery device, relative to a flow direction of the first fluid in the first circuit.

Alternatively, the second heat exchanger of the heat recovery device may be upstream of the first heat exchanger of the heat recovery device, relative to the flow direction of the first fluid in the first circuit.

• un organe de compression configuré pour comprimer le troisième fluide circulant dans le troisième circuit en amont de l’au moins un échangeur de chaleur du dispositif de valorisation relativement à un sens d’écoulement du troisième fluide dans le troisième circuit,
• un organe de réduction de pression configuré pour réduire la pression du troisième fluide circulant dans le troisième circuit en aval de l’au moins un échangeur de chaleur du dispositif de valorisation relativement au sens d’écoulement du troisième fluide dans le troisième circuit.

In one embodiment, the installation comprises:

• a compression member configured to compress the third fluid circulating in the third circuit upstream of the at least one heat exchanger of the recovery device relative to a flow direction of the third fluid in the third circuit,
• a pressure reducing member configured to reduce the pressure of the third fluid circulating in the third circuit downstream of the at least one heat exchanger of the recovery device relative to the flow direction of the third fluid in the third circuit.

According to a first variant embodiment, the at least one heat exchanger of the recovery device comprises a heat exchanger configured to be able to transfer heat from the third fluid circulating in the third circuit to the second fluid circulating in the second circuit in order to increase the temperature of the second fluid.

According to a second variant embodiment, the at least one heat exchanger of the recovery device comprises a heat exchanger configured to be able to transfer heat from the third fluid circulating in the third circuit to said gas flow circulating in the fourth circuit in order to increase the temperature of this gas flow.

• un échangeur de chaleur configuré pour pouvoir transférer de la chaleur du troisième fluide circulant dans le troisième circuit au deuxième fluide circulant dans le deuxième circuit afin d’augmenter la température du deuxième fluide, et
• un échangeur de chaleur configuré pour pouvoir transférer de la chaleur du troisième fluide circulant dans le troisième circuit audit flux gazeux circulant dans le quatrième circuit afin d’augmenter la température de ce flux gazeux.

The first variant and the second variant embodiment described above can be combined so that, according to a third variant embodiment, the at least one heat exchanger of the recovery device comprises both:

• a heat exchanger configured to be able to transfer heat from the third fluid circulating in the third circuit to the second fluid circulating in the second circuit in order to increase the temperature of the second fluid, and
• a heat exchanger configured to be able to transfer heat from the third fluid circulating in the third circuit to said gas flow circulating in the fourth circuit in order to increase the temperature of this gas flow.

In one embodiment, the installation comprises a device for treating the fourth fluid configured to change the fourth fluid from the liquid state to the gaseous state.

Preferably, said fourth circuit comprises one or more conduits establishing fluid communication between this treatment device and the superheating device.

In one embodiment, the recovery device is configured to be able to transfer heat from the third fluid circulating in the third circuit to the fourth fluid circulating in this or these conduits.

In one embodiment, said fourth fluid treatment device comprises an evaporator configured to carry out heat exchange between the second fluid circulating in the second circuit and the fourth fluid circulating in the fourth circuit.

In one embodiment, the installation comprises a thermal storage device configured to be able to store heat from the second fluid circulating in the second circuit.

• une configuration, dite « configuration d’échange direct », dans laquelle le deuxième circuit est configuré pour acheminer le deuxième fluide du premier étage du dispositif de récupération de chaleur au dispositif de surchauffe,
• une configuration, dite « configuration de déchargement thermique », dans laquelle le deuxième circuit est configuré pour acheminer le deuxième fluide du dispositif de stockage thermique au dispositif de surchauffe.

The installation can be configured to be selectively placed in:

• a configuration, called a “direct exchange configuration”, in which the second circuit is configured to convey the second fluid from the first stage of the heat recovery device to the superheating device,
• a configuration, called a “thermal discharge configuration”, in which the second circuit is configured to convey the second fluid from the thermal storage device to the superheating device.

The installation thus makes it possible to heat the gas flow passing through the superheating device using heat which is either recovered in the second fluid coming from the first stage of the heat recovery device or stored in the thermal storage device.

The invention thus makes it possible to produce steam using a fatal heat source while ensuring a continuous supply of steam despite fluctuations in the flow rate or temperature of the source.

The installation can be configured to be selectively placed in a configuration chosen from a list including, in addition to the direct exchange configuration and the thermal discharge configuration, one or more configurations from those described below.

In one embodiment, said list includes a configuration, called a "thermal loading configuration", in which the second circuit is configured to convey the second fluid from the first stage of the heat recovery device to the thermal storage device.

The thermal loading configuration advantageously allows heat recovered from the input fluid to be stored in the thermal storage device.

In one embodiment, said list includes a configuration, called a "mixed configuration", in which the second circuit is configured to convey the second fluid from the first stage of the heat recovery device to the thermal storage device and from the thermal storage device to the superheating device.

The mixed configuration advantageously makes it possible both to heat the gas flow passing through the superheating device using heat recovered from the inlet fluid and to store heat recovered from the inlet fluid in the thermal storage device.

In one embodiment, the installation comprises a heating device configured to raise the temperature of the second fluid upstream of the superheating device.

Such a heating device advantageously makes it possible to heat the gas flow passing through the superheating device using an external energy source, for example when the energy available in the thermal storage device or in the inlet fluid is insufficient, and/or to facilitate the start-up of the installation.

The heating device can be electric.

In one embodiment, the second circuit includes a bypass branch of the heating device.

The second circuit may be configured to route the second fluid from the first stage of the heat recovery device to the superheating device via the bypass branch when the installation is in said direct exchange configuration.

The second circuit may be configured to route the second fluid from the thermal storage device to the superheating device through the bypass branch when the installation is in said thermal unloading configuration and/or in the mixed configuration.

In one embodiment, said list includes a configuration, called "electrical configuration", in which the second circuit is configured to convey the second fluid from the first stage of the heat recovery device to the heating device and from the heating device to the superheating device.

The electrical configuration advantageously makes it possible to heat the gas flow passing through the superheating device using an external energy source, for example when the energy available in the thermal storage device is insufficient.

In one embodiment, said list includes a configuration in which the second circuit is configured to route the second fluid from the first stage of the heat recovery device to the heating device and from the heating device to the superheating device.

Such a configuration advantageously makes it easier to start the installation, for example before placing the installation in said direct exchange configuration.

In one embodiment, said list includes a configuration in which the second circuit is configured to route the second fluid from the first stage of the heat recovery device to the thermal storage device, from the thermal storage device to the heating device, and from the heating device to the superheating device.

Such a configuration advantageously makes it easier to start up the installation, for example before placing the installation in said mixed configuration.

In one embodiment, the installation comprises a sensor configured to estimate the temperature of said first fluid and control means configured to place the installation in said direct exchange configuration if the estimated temperature of the first fluid is greater than a first predetermined temperature threshold and less than a second predetermined temperature threshold, the second threshold being less than the first threshold.

In one embodiment, the control means are configured to place the installation in said mixed configuration if the estimated temperature of the first fluid is greater than or equal to said second threshold.

In one embodiment, the first temperature threshold corresponds to the addition of a measured or desired temperature of the gas flow leaving the superheating device and a first constant temperature value, said first constant temperature value being for example equal to 5°C.

In one embodiment, the second temperature threshold corresponds to the addition of a measured or desired temperature of the gas flow leaving the superheating device and a second constant temperature value, said second constant temperature value being for example equal to 20°C.

The installation can of course include other components.

For example, but not limited to, the installation may include a steam production module comprising said superheating device.

In one embodiment, the vapor production module may include an evaporator configured to convert the output fluid from a liquid state to a gaseous state.

• une étape de récupération de chaleur dans laquelle de la chaleur est transférée :
  • du premier fluide circulant dans le premier circuit au deuxième fluide circulant dans le deuxième circuit afin d’augmenter la température de ce deuxième fluide, à l’aide du premier étage du dispositif de récupération de chaleur,
  • du premier fluide circulant dans le premier circuit au troisième fluide circulant dans le troisième circuit afin d’augmenter la température de ce troisième fluide, à l’aide du deuxième étage du dispositif de récupération de chaleur,
• une étape de surchauffe dans laquelle de la chaleur est transférée, à l’aide du dispositif de surchauffe, du deuxième fluide circulant dans le deuxième circuit au flux gazeux du quatrième fluide circulant dans le quatrième circuit afin d’augmenter la température de ce flux gazeux,
• une étape de valorisation dans laquelle de la chaleur est transférée, à l’aide de l’au moins un échangeur de chaleur du dispositif de valorisation, du troisième fluide circulant dans le troisième circuit :
  • au deuxième fluide circulant dans le deuxième circuit afin d’augmenter la température du deuxième fluide, et/ou
  • audit flux gazeux du quatrième fluide circulant dans le quatrième circuit afin d’augmenter la température de ce flux gazeux.

The invention also relates to a method for supplying steam using an installation as defined above, comprising:

• a heat recovery stage in which heat is transferred:
  • from the first fluid circulating in the first circuit to the second fluid circulating in the second circuit in order to increase the temperature of this second fluid, using the first stage of the heat recovery device,
  • from the first fluid circulating in the first circuit to the third fluid circulating in the third circuit in order to increase the temperature of this third fluid, using the second stage of the heat recovery device,
• a superheating step in which heat is transferred, using the superheating device, from the second fluid circulating in the second circuit to the gas flow of the fourth fluid circulating in the fourth circuit in order to increase the temperature of this gas flow,
• a recovery step in which heat is transferred, using the at least one heat exchanger of the recovery device, from the third fluid circulating in the third circuit:
  • to the second fluid circulating in the second circuit in order to increase the temperature of the second fluid, and/or
  • said gas flow of the fourth fluid circulating in the fourth circuit in order to increase the temperature of this gas flow.

The method may of course include steps corresponding to the implementation of one or more configurations described above and/or other steps of implementing the installation.

For example, in a non-limiting manner, the method may comprise an evaporation step, in which said evaporator is implemented to change the output fluid from the liquid state to the gaseous state.

Compared to steam production technologies using an electrical source, the invention makes it possible to substantially reduce electrical energy consumption.

The invention also makes it possible to produce industrial steam without using a combustion generator, thereby substantially reducing pollutant emissions, including carbon dioxide.

The invention can be implemented in many industrial applications, for example by using steam in the context of hydrogen production processes by electrolysis or within a steam turbine thermal power station.

Other advantages and characteristics of the invention will appear on reading the detailed, non-limiting description which follows.

• est une vue schématique d’une installation de fourniture de vapeur selon un premier mode de réalisation ;
• est une vue schématique d’une installation de fourniture de vapeur selon un deuxième mode de réalisation ;
• est une vue schématique d’une installation de fourniture de vapeur selon un troisième mode de réalisation, l’installation étant dans une première configuration ;
• est une vue schématique de l’installation de la dans une deuxième configuration ;
• est une vue schématique de l’installation de la dans une troisième configuration ;
• est une vue schématique de l’installation de la dans une quatrième configuration ;
• est une vue schématique de l’installation de la dans une cinquième configuration ;
• est une vue schématique de l’installation de la dans une sixième configuration ;
• est une vue schématique de l’installation de la dans une septième configuration.

The following detailed description refers to the attached drawings in which:

• is a schematic view of a steam supply installation according to a first embodiment;
• is a schematic view of a steam supply installation according to a second embodiment;
• is a schematic view of a steam supply installation according to a third embodiment, the installation being in a first configuration;
• is a schematic view of the installation of the in a second configuration;
• is a schematic view of the installation of the in a third configuration;
• is a schematic view of the installation of the in a fourth configuration;
• is a schematic view of the installation of the in a fifth configuration;
• is a schematic view of the installation of the in a sixth configuration;
• is a schematic view of the installation of the in a seventh configuration.

Detailed description of embodiments

There shows in a schematic and simplified manner an installation 100 conforming to a first embodiment of the invention.

The installation 100 comprises different fluid circuits 1 to 4 respectively receiving a first fluid, a second fluid, a third fluid and a fourth fluid.

In this non-limiting example, the first fluid, also called “input fluid”, is a fluid originating from a fatal heat source which may be in the gaseous and/or liquid state. For information purposes, the input fluid may comprise a combustion gas, air or even water vapor.

The second fluid is a heat transfer fluid such as oil or water.

The third fluid is also a heat transfer fluid, in this example a refrigerant gas comprising for example hydrofluorocarbons or hydrochlorofluorocarbons or comprising alkyl halides or even a halogenated olefin.

The fourth fluid, also called the “output fluid,” in this example includes water.

Installation 100 of the includes heat exchangers 6, 7, 8 and 9A.

In this example, each of the exchangers 6 and 7 is configured to be able to recover heat from the inlet fluid circulating in the circuit 1 in order to transfer a portion of it to the heat transfer fluid circulating in the circuit 2 and to the heat transfer fluid circulating in the circuit 3, respectively.

For information purposes, the exchanger 6 may be an exchanger of the economizer-recuperator type, for example a tube and fin exchanger, or a plate exchanger. The exchanger 7 may be an exchanger of the evaporator type of a heat pump cycle.

With reference to a direction of flow of the inlet fluid in the circuit 1, the exchanger 7 is in this example arranged downstream of the exchanger 6.

The exchangers 6 and 7 thus form a two-stage heat recovery device 11, the first stage being formed by the exchanger 6, the second stage being formed by the exchanger 7.

In this example, the exchanger 8 forms a superheating device configured to be able to transfer heat from the heat transfer fluid circulating in the circuit 2 to the outlet fluid circulating in the circuit 4.

In this example, the exchanger 9A is configured to be able to transfer heat from the heat transfer fluid circulating in the circuit 3 to the heat transfer fluid circulating in the circuit 2. In a non-limiting manner, the exchanger 9A may be a condenser type exchanger of a heat pump cycle.

In this non-limiting example, the circuit 2 comprises a branch 2A configured to convey the heat transfer fluid leaving the exchanger 6 to the exchanger 8, a branch 2B configured to convey a portion of the heat transfer fluid leaving the exchanger 8 to the exchanger 6, a branch 2C configured to convey another portion of the heat transfer fluid leaving the exchanger 8 to the exchanger 9A and a branch 2D configured to inject the heat transfer fluid leaving the exchanger 9A into the branch 2A of the circuit 2, that is to say downstream of the exchanger 6 and upstream of the exchanger 8 relative to the direction of flow of the fluid in the branch 2A.

The installation 100 can be implemented to supply steam to said output fluid, here water vapor.

To do this, the fluids circulating in the installation 100 typically have respective temperatures such that the superheating device 8 transfers heat from the heat transfer fluid circulating in the circuit 2 to the outlet fluid, the latter arriving in the superheating device 8 in the form of a gas flow. The superheating device 8 can thus increase the temperature of this gas flow. The heat transfer fluid circulating in the circuit 2 first recovers heat from the inlet fluid within the exchanger 6 and is then mixed with a fraction of fluid coming from the branch 2D which has been heated within the exchanger 9A by the heat transfer fluid circulating in the circuit 3. The fluid circulating in the circuit 3 arrives in the exchanger 9A after having been heated within the exchanger 7 by the inlet fluid.

The second stage of the device 11 thus makes it possible to recover heat from the input fluid which has not been recovered at the level of the first stage and to transfer, via the exchanger 9A, part of this heat to the heat transfer fluid circulating in the circuit 2.

Exchanger 9A and circuit 3 form a device 12 called a “recovery device”.

The installation 100 thus makes it possible to increase the temperature of the heat transfer fluid arriving in the superheating device 8 by using the residual heat from the inlet fluid leaving the first stage of the device 11, thereby increasing the temperature of the steam produced by the installation 100.

There shows in a schematic and simplified manner an installation 200 conforming to a second embodiment of the invention.

Installation 200 of the differs from the 100 installation of the in that the recovery device 12 comprises, in place of the exchanger 9A, an exchanger 9B and in that the circuit 4 comprises a branch 4A configured to convey to the exchanger 9B a portion of the outlet fluid in the liquid state and a branch 4B configured to inject the outlet fluid leaving the exchanger 9B into a branch 4C of the circuit 4, the branch 4C being configured to introduce the outlet fluid into the superheating device 8.

Unlike the 100 installation of the , circuit 2 of installation 200 of the is, in this example, devoid of branches 2C and 2D (see ).

The description of the the foregoing applies by analogy to the embodiment of the .

Installation 200 of the can also be implemented to provide steam from the outlet fluid, the heat transfer fluid circulating in the circuit 2 recovering heat from the inlet fluid within the exchanger 6, the fluid circulating in the circuit 3 arriving in the exchanger 9B after having been reheated within the exchanger 7 by the inlet fluid, the outlet fluid arriving in the gaseous state in the superheating device 8 after having been reheated by mixing with a fraction of fluid coming from the exchanger 9B via the branch 4B of the circuit 4. Thus, the second stage of the device 11 makes it possible to recover in the inlet fluid heat not recovered by its first stage and to transfer, via the exchanger 9B, a portion of this heat to the outlet fluid, upstream of the superheating device 8.

The installation 200 therefore also makes it possible to recover residual heat from the inlet fluid downstream of the first stage of the recovery device 11 by increasing the temperature of the steam thus produced.

The principles of the installations 100 and 200 described above can be combined, in particular by arranging in series or in parallel, in the circuit 3, both an exchanger such as the exchanger 9A of the and an exchanger such as exchanger 9B of the , in order to be able to transfer heat from the inlet fluid recovered by the second stage of the device 11, simultaneously or alternately, both to the heat transfer fluid circulating in the circuit 2 and to the outlet fluid circulating in the circuit 4.

Without limitation, the shows a third embodiment which thus combines the principles of the installations 100 and 200 described above. The preceding description applies by analogy to the embodiment of the .

There shows an installation 300 which comprises organs or components which are also present in the installations 100 and 200 described above, in particular the exchangers 6 and 7 forming the double-stage heat recovery device 11 and the exchanger 8 forming the superheating device, as well as the circuits 1, 2, 3 and 4 which have, compared to the circuits of figures 1 and 2, some differences described below.

The installation 300 also includes a recovery device 12 which includes both a first exchanger intended to fulfill the same function as the exchanger 9A of the and a second exchanger intended to fulfill the same function as exchanger 9B of the . The first exchanger and the second exchanger of the recovery device 12 of the installation 300 are referenced 9A and 9B, taking into account their function similar to the exchangers 9A and 9B of figures 1 and 2, respectively.

Compared to the simplified representation of Figures 1 and 2, the shows some additional, non-limiting, structural details of the installation 300, which are described below.

The installation 300 comprises in particular, in this example, a thermal storage device 14 configured to be able to store heat from the heat transfer fluid circulating in the circuit 2, when the installation 300 operates in an energy storage mode (see further below).

For information purposes, the device 14 may be in the form of a heat-insulated tank. In a non-limiting alternative embodiment, such a tank comprises a heat storage medium, for example rocks.

With reference to the part of the installation 300 forming the circuit 4 (towards the right and the top of the ), the installation 300 comprises in this example a degasser 15, an evaporator 16, a pump 17, valves 18 and 19 and conduits 20-30 for conveying the outlet fluid, which is here water.

In this example, the water arrives in the liquid state in the degasser 15, of the steam thermal degasser type, via the conduit 20 coming for example from a water treatment unit (not shown). The degasser 15 makes it possible to eliminate gases such as oxygen dissolved in the water, and to evacuate them via the conduit 21 which can be a vent.

The pump 17 makes it possible to extract the water thus treated from the degasser 15 and to convey it to the evaporator 16 via the conduits 22, 23 and 24, at a pressure which can typically be between 1 bara (10 ⁵ Pa) and 15 bara (15 x 10 ⁵ Pa).

The evaporator 16 makes it possible to convert the water into a gaseous state, in the form of saturated water vapor. In a non-limiting manner, the evaporator 16 may comprise a kettle or plate type exchanger.

The valve 19 allows on the one hand to convey all or part of this saturated steam to the degasser 15, via the conduits 25 and 27, so as to preheat the water while maintaining it in the degasser 15 at a constant temperature.

The valve 19 also makes it possible to route all or part of the saturated steam leaving the evaporator 16 to the superheating device 8, via the conduits 25 and 26, so as to constitute said gas flow.

The superheating device 8, the degasser 15 and the evaporator 16 form a steam production module, which leaves the installation 300 via the conduit 30.

With reference to the part of the installation 300 forming the circuit 2 (central part towards the top of the ), the installation 300 comprises in this example an expansion tank 31, a heating device 32, pumps 33-35, a thermal storage member 36, valves 40-46 and conduits 50-69 configured to receive the heat transfer fluid at a pressure which can typically be between 1 bara (10 ⁵ Pa) and 40 bara (40 x 10 ⁵ Pa).

The heating device 32 comprises in this example an electric heater supplied by the storage member 36.

Exchanger 6 and driver 32 are connected to each other by conduits 50 to 53, via valves 40, 41 and 42.

The heater 32 and the superheating device 8 are connected to each other by the conduits 54 and 56 via the valve 43.

The conduit 55 is connected to the valves 42 and 43 so as to form a bypass branch of the driver 32.

The superheating device 8 and the evaporator 16 are connected to each other by the conduit 57.

The evaporator 16 and the pump 33 are connected to each other by the conduit 58.

Pump 33 and exchanger 6 are connected to each other by conduits 59, 60, 64 and 65 via valves 44, 45 and 46.

The expansion tank 31 is connected to the conduit 59 by the valve 44 via the conduit 69.

The energy storage device 14 is connected on the one hand to the exchanger 6 by the conduits 50 and 66 via the valve 40 and, on the other hand, to the pump 35 by the conduit 67, the pump 35 being connected to the conduit 65 by the conduit 68 via the valve 46.

The energy storage device 14 is also connected on the one hand to the pump 34 by the conduit 62, the pump 34 being connected to the valve 41 by the conduit 63 and, on the other hand, to the valve 45 by the conduit 61.

With reference to the part of the installation 300 comprising circuit 1 (towards the left and the top of the ), the installation 300 comprises in this example a control valve 70 which is linked to the circuit 2 by an information feedback line 71 and is configured to adjust the flow rate of the fluid conveyed into the exchanger 6 by the circuit 1 so that the temperature of the heat transfer fluid circulating in the conduit 50 of the circuit 2 remains below a temperature threshold. This threshold may typically be 350°C, or more preferably 250°C.

As an indication, the inlet fluid circulating in circuit 1 can have a temperature between 50°C and 1000°C.

In this example, the installation 300 comprises a heat storage device 72 which is configured to recover and store heat from the input fluid circulating in the circuit 1, upstream of the exchanger 6.

With reference to the part of the installation 300 forming the circuit 3 (towards the bottom of the ), the installation 300 comprises, in a non-limiting manner, a compression member 81, a pressure reduction member 82, valves 83 and 84 and conduits 85-92.

In a non-limiting manner, the compression member 81 may be formed by a compressor of a heat pump cycle and the pressure reduction member 82 may be an expansion valve or expansion valve of a heat pump cycle.

The heat transfer fluid circulating in circuit 3 leaves exchanger 7 to be conveyed to valve 83 via conduits 85 and 86 passing through member 81 which is configured to compress this fluid upstream of exchangers 9A and 9B.

The valve 83 makes it possible to direct the fluid towards the exchanger 9A via the conduit 87 and/or towards the exchanger 9B via the conduit 89, the exchangers 9A and 9B being in this example arranged in parallel in the circuit 3.

The fluid circulating in circuit 3 leaves exchanger 9A and/or 9B and is conveyed to member 82 via conduit 88 or 90, respectively, then via valve 84 and conduit 91.

The member 82 is configured to reduce the pressure of the heat transfer fluid circulating in the circuit 3, downstream of the exchangers 9A and 9B, before its arrival in the exchanger 7 via the conduit 92.

The exchanger 9A is configured to carry out a heat exchange between the heat transfer fluid circulating in the circuit 3 and the heat transfer fluid circulating in a part of the circuit 2 formed by conduits 94 and 95. The conduit 94 is in this example arranged to convey the fluid circulating in the circuit 2 from the valve 46 to the exchanger 9A and the conduit 95 to convey this fluid leaving the exchanger 9A to the valve 40 of the circuit 2.

The exchanger 9B is configured to carry out a heat exchange between the heat transfer fluid circulating in the circuit 3 and the outlet fluid circulating in a part of the circuit 4 formed by the conduits 28 and 29. In this example, the conduit 28 is arranged to convey the inlet fluid from the valve 18 to the exchanger 9B and the conduit 29 to convey this fluid leaving the exchanger 9B to the valve 19 of the circuit 4.

Installation 300 of the is configured to be able to be placed, selectively, in different configurations described further below with reference to FIGS. 3 to 9, including configurations in which the installation 300 operates in steam supply mode, configurations in which the installation 300 operates in energy storage mode and configurations in which the installation 300 operates in both steam supply mode and energy storage mode.

Generally speaking, in the energy storage mode, the fluids circulating in the installation 300 have respective temperatures such that, on the one hand, the exchanger 6 transfers heat from the input fluid circulating in the circuit 1 to the heat transfer fluid circulating in the circuit 2, thus increasing the temperature of this heat transfer fluid and, on the other hand, the energy storage device 14 stores heat from the heat transfer fluid thus heated.

Each of Figures 3 to 9 shows a respective configuration, in which the valves 40 to 46 of circuit 2, the valves 83 and 84 of circuit 3 and the valves 18 and 19 of circuit 4 are configured to circulate the heat transfer fluids and the outlet fluid in respective conduits of the installation 300 indicated by broken lines.

There shows the 300 installation in a C1 configuration, also called a "direct exchange configuration."

In configuration C1, valves 40-46 of circuit 2 are configured to convey the heat transfer fluid from exchanger 6 to superheating device 8 via conduits 50, 51, 52, 55 and 56, then from superheating device 8 to evaporator 16 via conduit 57, then from evaporator 16 to exchanger 6 via conduits 58, 59, 60, 64 and 65, under the action of pump 33.

Thus, the heat transfer fluid of circuit 2 passes directly from the exchanger 6 to the superheating device 8, without passing through the thermal storage device 14 and bypassing the heater 32 via the branch 55. At the outlet of the evaporator 16, the heat transfer fluid is directly returned to the exchanger 6 under the action of the pump 33, without passing through the thermal storage device 14.

The direct exchange configuration C1 thus implements the steam supply mode and does not implement the energy storage mode.

The installation 300 is typically placed in the direct exchange configuration C1 when the inlet fluid circulating in the circuit 1 has a temperature slightly higher than that of the gas flow leaving the superheating device 8 via the conduit 30, for example with a difference of between 5°C and 20°C.

In this example, when the installation 300 is in direct exchange configuration C1 and when the temperature of the inlet fluid at the outlet of the exchanger 6 is sufficient, the device 12 is configured so that the exchanger 7 transfers heat from the inlet fluid to the heat transfer fluid circulating in the circuit 3 then, on the one hand, to the fluid circulating in the conduits 94 and 95 via the exchanger 9A and, on the other hand, to the outlet fluid circulating in the conduits 28 and 29 via the exchanger 9B.

Figures 4 to 9 show the installation 300 of the in other configurations, with the same components in the same arrangement, the reference signs of these components placed on the not all of which are however included in figures 4 to 9 in order to avoid overloading them.

The description of the The above applies by analogy to Figures 4 to 9, which are described below only according to their differences from configuration C1 of the .

There shows the 300 installation in a C2 configuration, also called a “thermal loading configuration”.

In configuration C2, the valves of circuit 2 are configured to convey the heat transfer fluid from exchanger 6 to thermal storage device 14 via conduits 50 and 66 and from thermal storage device 14 to exchanger 6 via conduits 67, 68 and 65, under the action of pump 35.

Thus, the heat transfer fluid of circuit 2 passes directly from exchanger 6 to thermal storage device 14 without passing through the steam production module or the part of circuit 2 comprising the heater 32.

Thus, the thermal loading configuration C2 implements the energy storage mode and does not implement the steam supply mode.

The installation 300 is typically placed in the thermal loading configuration C2 when the inlet fluid circulating in the circuit 1 has a sufficient temperature to allow heat storage and, either when it is not desired to produce steam with the installation 300, or because the temperature of the inlet fluid is insufficient to heat the gas flow within the superheating device 8.

In this example, when the installation 300 is in thermal loading configuration C2 and when the temperature of the inlet fluid at the outlet of the exchanger 6 is sufficient, the device 12 is configured so that the exchanger 7 transfers heat from the inlet fluid to the fluid circulating in the circuit 3 then to the fluid circulating in the conduits 94 and 95 of the circuit 2 via the exchanger 9A. The valves 83 and 84 are configured to circulate the heat transfer fluid in the part of the circuit 3 comprising the exchanger 9A, via the conduits 85, 86, 87, 88, 91 and 92 and not to circulate it in the part of the circuit comprising the exchanger 9B.

There shows the 300 installation in a C3 configuration, also called a “thermal unloading configuration.”

In configuration C3, the valves of circuit 2 are configured to convey the heat transfer fluid from the thermal storage device 14 to the superheating device 8 via the conduits 62, 63, 52, 55 and 56, then from the superheating device 8 to the evaporator 16 via the conduit 57, then from the evaporator 16 to the thermal storage device 14 via the conduits 58, 59, 60 and 61, under the action of the pump 33.

Thus, the heat transfer fluid passes directly from the thermal storage device 14 to the superheating device 8, bypassing the heater 32 via the branch 55.

The C3 thermal unloading configuration thus implements the steam supply mode and does not implement the energy storage mode.

The installation 300 is typically placed in the thermal unloading configuration C3 when the temperature of the inlet fluid circulating in the circuit 1 is insufficient both to store heat in the thermal storage device 14 and to superheat the gas flow within the superheating device 8, and when the quantity of heat stored by the device 14 is sufficient to superheat the gas flow within the superheating device 8.

In this example, when the installation 300 is in thermal unloading configuration C3, the device 12 is inactive, that is to say that neither the exchanger 9A nor the exchanger 9B transfers heat from the fluid circulating in the circuit 3 to the fluid circulating in the circuit 2 or to the outlet fluid.

There shows the 300 installation in a C4 configuration, also called a “mixed configuration”.

In the mixed configuration C4, the valves of the circuit 2 are configured to convey the heat transfer fluid from the exchanger 6 to the thermal storage device 14 via the conduits 50 and 66, then from the thermal storage device 14 to the superheating device 8 via the conduits 62, 63, 52, 55 and 56, then from the superheating device 8 to the evaporator 16 via the conduit 57, then from the evaporator 16 to the exchanger 6 via the conduits 58, 59, 60, 64 and 65, under the action of the pump 33.

Thus, the heat transfer fluid of circuit 2 passes from exchanger 6 to superheating device 8 via thermal storage device 14, bypassing heater 32 via branch 55. At the outlet of evaporator 16, the heat transfer fluid is directly returned to exchanger 6 under the action of pump 33, without passing through thermal storage device 14.

The mixed C4 configuration thus implements both the steam supply mode and the energy storage mode.

The installation 300 is typically placed in the mixed configuration C4 when the inlet fluid circulating in the circuit 1 has a temperature much higher than that of the gas flow leaving the superheating device 8, for example a difference greater than or equal to 20°C.

In this example, when the installation 300 is in mixed configuration C4 and when the temperature of the inlet fluid at the outlet of the exchanger 6 is sufficient, the device 12 is configured so that the exchanger 7 transfers heat from the inlet fluid to the heat transfer fluid circulating in the circuit 3 then, on the one hand, to the fluid circulating in the conduits 94 and 95 via the exchanger 9A and, on the other hand, to the outlet fluid circulating in the conduits 28 and 29 via the exchanger 9B.

There shows the 300 installation in a C5 configuration, also called an “electrical configuration,” which is described below only in terms of its differences from the C3 configuration.

Configuration C5 differs from configuration C3 in that the heat transfer fluid of circuit 2 passes from the thermal storage device 14 to the superheating device 8 via the electric heater 32, i.e. via the conduits 53 and 54 and not via the bypass conduit 55.

Configuration C5 therefore also implements the steam supply mode and does not implement the energy storage mode.

The installation 300 is typically placed in the electrical configuration C5 when the quantity of heat stored by the device 14 is insufficient to superheat the gas flow within the superheating device 8.

Configuration C5 may be implemented temporarily during start-up of the installation 300, before switching to the thermal unloading configuration C3 when thermodynamic conditions are stabilized or when sufficient temperatures are reached.

The same applies to the direct exchange configuration C1 and the mixed configuration C4 which can be implemented after a start-up of the installation 300 placed in the configurations C6 and C7, respectively (see below).

There shows the 300 installation in a C6 configuration which is described below only according to its differences from the C1 configuration.

Configuration C6 differs from configuration C1 in that the heat transfer fluid of circuit 2 passes from exchanger 6 to superheating device 8 via electric heater 32, i.e. via conduits 53 and 54 and not via bypass conduit 55.

There shows the 300 installation in a C7 configuration which is described below only according to its differences from the C4 configuration.

Configuration C7 differs from configuration C4 in that the heat transfer fluid of circuit 2 passes from the thermal storage device 14 to the superheating device 8 via the electric heater 32, i.e. via the conduits 53 and 54 and not via the bypass conduit 55.

Configurations C5, C6 and C7 can thus be implemented as an electric start configuration.

In configurations C6 and C7, device 12 may optionally be inactive.

The change of configuration of the installation 300 can be carried out by control means (not shown), in particular by controlling the valves of circuits 2, 3 and 4.

The installation 300 may comprise one or more sensors (not shown), for example a temperature sensor for the inlet fluid circulating in the circuit 1, upstream of the exchanger 6, and a temperature sensor for the inlet fluid circulating in the circuit 1, downstream of the exchanger 6.

The control means may be configured to place the installation 300 in one or other of the configurations described above depending on one or more parameters which may include the temperature of the inlet fluid measured using one or more of the aforementioned sensors.

For example, the control means may be configured to place the installation 300 in the direct exchange configuration C1 if the measured or estimated temperature of the inlet fluid is greater than a first predetermined temperature threshold and less than a second predetermined temperature threshold.

In a non-limiting manner, the first threshold, respectively the second threshold, may correspond to a temperature of 5°C, respectively 20°C, above a measured or desired temperature of the gas flow leaving the superheating device 8.

For another non-limiting example, the control means can be configured to place the installation 300 in the mixed configuration C4 if the measured or estimated temperature of the inlet fluid is higher than said second threshold.

Among other advantages of the 300 installation, it makes it possible to supply steam from the outlet fluid, here water vapor, in a substantially continuous manner despite temporary variations in the temperature and/or flow rate of the inlet fluid.

In a non-limiting manner, each of the installations 100, 200 and 300 described above can be implemented to provide steam to a process for producing hydrogen by high-temperature electrolysis. The invention can of course be implemented in numerous applications for producing industrial steam and using an industrial installation such as a cement plant or other as a source of fatal heat.

Of course, many variations can be made to the above description. For example, the steam production module can comprise steam generation members other than the degasser 15 and the evaporator 16 described above and/or members arranged differently and/or produce steam from a fluid comprising different combinations of gases. As an example of an alternative embodiment, the steam production module can be devoid of the recirculation conduit 27 between the evaporator 16 and the degasser 15.

In the example of Figures 3 to 9, the installation 300 comprises an expansion tank 31 which can be implemented by opening the valve 44 (see ). In a non-limiting manner, the expansion tank 31 may be a membrane or bladder tank. In alternative embodiments, such an expansion tank 31 may be mounted on another part of the circuit 2 or be removed.

Similar variants may be applied to the installations 100 and 200 of FIGS. 1 and 2 and each of the installations 100, 200 and 300 described above may comprise additional members and/or components arranged differently than in the . For example, the pump 33 can be mounted between the superheating device 8 and the evaporator 16.

For another example, the recovery device 12 of the installation 300 of the can be replaced by device 12 of installation 100 of the or installation 200 of the or by similar and/or otherwise arranged recovery devices.

Claims (9)

Steam supply installation (100, 200, 300), comprising:

• a heat recovery device (11) having:
  • a first stage (6) configured to be able to transfer heat from a first fluid circulating in a first circuit (1) to a second heat transfer fluid circulating in a second circuit (2) in order to increase the temperature of this second fluid, and
  • a second stage (7) configured to be able to transfer heat from the first fluid circulating in the first circuit (1) to a third heat transfer fluid circulating in a third circuit (3) in order to increase the temperature of this third fluid,
• a superheating device (8) configured to be able to transfer heat from the second fluid circulating in the second circuit (2) to a gas flow of a fourth fluid circulating in a fourth circuit (4) in order to increase the temperature of this gas flow,
• a recovery device (12) comprising at least one heat exchanger (9A, 9B) configured to be able to transfer heat from the third fluid circulating in the third circuit (3):
  • to the second fluid circulating in the second circuit (2) in order to increase the temperature of the second fluid upstream of the superheating device (8) relative to a flow direction of the second fluid in the second circuit (2), and/or
  • said gas flow of the fourth fluid circulating in the fourth circuit (4) in order to increase the temperature of this gas flow.

Installation (100, 200, 300) according to claim 1, in which the heat recovery device (11) comprises a first heat exchanger (6) forming said first stage and a second heat exchanger (7) forming said second stage, the second heat exchanger (7) preferably being downstream of the first heat exchanger (6) relative to a flow direction of the first fluid in the first circuit (1). Installation (300) according to claim 1 or 2, comprising:

• a compression member (81) configured to compress the third fluid circulating in the third circuit (3) upstream of the at least one heat exchanger (9A, 9B) of the recovery device (12) relative to a flow direction of the third fluid in the third circuit (3),
• a pressure reducing member (82) configured to reduce the pressure of the third fluid circulating in the third circuit (3) downstream of the at least one heat exchanger (9A, 9B) of the recovery device (12) relative to the flow direction of the third fluid in the third circuit (3).

Installation (100, 300) according to any one of claims 1 to 3, in which the at least one heat exchanger of the recovery device (12) comprises a heat exchanger (9A) configured to be able to transfer heat from the third fluid circulating in the third circuit (3) to the second fluid circulating in the second circuit (2) in order to increase the temperature of the second fluid. Installation (200, 300) according to any one of claims 1 to 4, in which the at least one heat exchanger of the recovery device (12) comprises a heat exchanger (9B) configured to be able to transfer heat from the third fluid circulating in the third circuit (3) to said gas flow circulating in the fourth circuit (4) in order to increase the temperature of this gas flow. Installation (300) according to any one of claims 1 to 5, comprising a treatment device (15, 16) for the fourth fluid configured to change the fourth fluid from the liquid state to the gaseous state, said fourth circuit (4) comprising one or more conduits (25, 26) establishing fluid communication between this treatment device (15, 16) and the superheating device (8), the recovery device (12) being configured to be able to transfer heat from the third fluid circulating in the third circuit (3) to the fourth fluid circulating in this or these conduits (25, 26). Installation (300) according to claim 6, in which said device for treating the fourth fluid comprises an evaporator (16) configured to carry out heat exchange between the second fluid circulating in the second circuit (2) and the fourth fluid circulating in the fourth circuit (4). Installation (300) according to any one of claims 1 to 7, comprising a thermal storage device (14) configured to be able to store heat from the second fluid circulating in the second circuit (2), the installation (300) being configured to be able to be selectively placed in:

• a configuration, called a “direct exchange configuration”, in which the second circuit (2) is configured to convey the second fluid from the first stage (6) of the heat recovery device (11) to the superheating device (8),
• a configuration, called a “thermal discharge configuration”, in which the second circuit (2) is configured to convey the second fluid from the thermal storage device (14) to the superheating device (8).

Method for supplying steam using an installation (100, 200, 300) according to any one of claims 1 to 8, comprising:

• a heat recovery stage in which heat is transferred:
  • from the first fluid circulating in the first circuit (1) to the second fluid circulating in the second circuit (2) in order to increase the temperature of this second fluid, using the first stage (6) of the heat recovery device (11),
  • from the first fluid circulating in the first circuit (1) to the third fluid circulating in the third circuit (3) in order to increase the temperature of this third fluid, using the second stage (7) of the heat recovery device (11),
• a superheating step in which heat is transferred, using the superheating device (8), from the second fluid circulating in the second circuit (2) to the gas flow of the fourth fluid circulating in the fourth circuit (4) in order to increase the temperature of this gas flow,
• a recovery step in which heat is transferred, using the at least one heat exchanger (9A, 9B) of the recovery device (12), from the third fluid circulating in the third circuit (3):
  • to the second fluid circulating in the second circuit (2) in order to increase the temperature of the second fluid, and/or
  • said gas flow of the fourth fluid circulating in the fourth circuit (4) in order to increase the temperature of this gas flow.