阅读说明：本技术 热化学热泵以及具有可变功率的热能再分配方法 (Thermochemical heat pump and method for redistributing thermal energy with variable power ) 是由 J-E·福雷 于 2018-12-03 设计创作，主要内容包括：本发明涉及一种热化学热泵,所述热化学热泵包括溶剂蒸发器(26)、与热源(27)热学关联的蒸发器交换器(49)、包括溶剂蒸汽输入口的反应装置(29)、包括至少一种可溶解在所述溶剂中的盐的盐组合物的至少一个源、与冷源热学关联的至少一个冷却交换器(81)。所述反应装置(29)包括至少一个冷凝反应器(52),所述冷凝反应器包括与所述冷却交换器连接的溶液输入口、与所述冷却交换器连接的溶液输出口、在所述冷凝反应器(52)的输出口与输入口之间的至少一个盐组合物注射、以及用于调整通过该注射引入到液体溶液中的每种盐的质量流量的调整装置。(The invention relates to a thermochemical heat pump comprising a solvent evaporator (26), an evaporator exchanger (49) thermally associated with a heat source (27), a reaction device (29) comprising an input for solvent vapour, at least one source of a salt composition comprising at least one salt soluble in the solvent, at least one cooling exchanger (81) thermally associated with a cold source. The reaction device (29) comprises at least one condensation reactor (52) comprising a solution input connected to the cooling exchanger, a solution output connected to the cooling exchanger, at least one injection of a salt composition between the output and the input of the condensation reactor (52), and adjusting means for adjusting the mass flow of each salt introduced into the liquid solution by this injection.)

1. A thermochemical heat pump comprising:

-an evaporator, called solvent evaporator (26), comprising:

a container (46) of volatile liquid solvent,

a heat exchanger, called evaporator exchanger (49), suitable to be able to be thermally associated with a thermal source, called heat source (27), and comprising a circuit with a volatile liquid solvent input coupled with a container of said volatile liquid solvent,

a volatile solvent vapor outlet, the solvent evaporator (26) being adapted to be able to deliver volatile solvent vapor vaporized by heat from the heat source,

-a reaction device (29) comprising:

the volatile solvent vapor inlet port,

at least one source of a composition, called salt composition, comprising at least one salt soluble in the volatile liquid solvent,

at least one heat exchanger, called cooling exchanger (81), suitable to be able to be thermally associated with a thermal source, called cold source (31),

-the vapour output of the solvent evaporator (26) is coupled with the vapour input of the reaction device (29),

-the reaction device (29) is adapted to cause condensation of the volatile solvent vapour and absorption of the salt composition to form a liquid solution, which is accompanied by generation of heat, which is rejected towards the heat sink (31) through the cooling exchanger (81),

characterized in that said reaction device (29) comprises:

-at least one reactor, called condensation reactor (52), comprising:

a liquid solution input port coupled to the cold liquid solution output port of the cooling exchanger,

the volatile solvent vapor inlet port,

a liquid solution outlet coupled to the hot liquid solution inlet of the cooling exchanger (81),

the condensation reactor (52) is adapted to bring the steam supplied by the steam input into contact with the cold liquid solution delivered to the liquid solution input, so as to cause condensation of the steam and mixing of the volatile liquid solvent thus formed by condensation with the cold liquid solution, resulting from said mixing a hot liquid solution delivered to the liquid solution output of the condensation reactor (52),

-at least one salt composition injection between the liquid solution output and the liquid solution input of at least one condensation reactor (52),

-adjusting means (67, 85) for adjusting the mass flow of each salt introduced into the liquid solution by at least one salt composition injection between the liquid solution output and the liquid solution input of at least one condensation reactor (52).

2. Thermochemical heat pump according to claim 1, characterized in that it comprises at least one dissolution reactor (57) as source of salt composition, said dissolution reactor being adapted to enable dissolution of at least one solid salt in said salt composition in an unsaturated liquid solution of said liquid solvent, said dissolution reactor (57) comprising at least one output port for conveying a flow of concentrated liquid solution forming said salt composition.

3. Thermochemical heat pump according to claim 1 or 2, characterized in that at least one salt composition injection is coupled with at least one output of the condensation reactor (52).

4. Thermochemical heat pump according to claims 2 and 3, characterized in that the salt composition injection is formed by an injection pipe (60) coupling at least one outlet of the dissolution reactor (57) with a pipe called common pipe (61) coupled with the liquid solution outlet of the condensation reactor (52).

5. Thermochemical heat pump according to claim 4, characterized in that said common duct (61) comprises a pump (62) downstream of the injection of the salt composition.

6. Thermochemical heat pump according to claim 4 or 5, characterized in that at least one dissolution reactor (57) comprises an unsaturated liquid solution input, coupled to the common pipe (61) through a supply pipe (64), the supply pipe (64) comprising a controlled valve for adjusting the flow of unsaturated liquid solution delivered to the input of the dissolution reactor (57).

7. Thermochemical heat pump according to claims 5 and 6, characterized in that the supply conduit (64) of the dissolution reactor is coupled with the common conduit (61) downstream of the pump (62).

8. Thermochemical heat pump according to claim 6 or 7, characterized in that it comprises a temperature sensor (53) of the cold liquid solution at the output of each cooling exchanger (81), and in that said regulation means (67, 85) are suitable for servoing the flow delivered by the controlled valve (67) of the supply duct (64) of at least one dissolution reactor (57) as a function of the temperature of the cold liquid solution measured by at least one such temperature sensor (53).

9. The thermochemical heat pump according to any of claims 4 to 8, characterized in that the common pipe (61) is coupled to the hot liquid solution input of each cooling exchanger (81) through a recirculation pipe (63) comprising a controlled valve (66) for adjusting the flow of hot liquid solution delivered to the cooling exchangers (81) and therefore the flow of cold liquid solution delivered to the input of each condensation reactor (52) coupled to the liquid solution output of the cooling exchanger.

10. Thermochemical heat pump according to claims 5 and 9, characterized in that the recirculation conduit (63) is coupled with the common conduit (61) downstream of the pump (62).

11. Thermochemical heat pump according to any of claims 1 to 10, characterized in that each evaporator, reaction means (29), each pipe in which the vapor circulates and each pipe in which the liquid solution circulates are at negative pressure under vacuum of the third gas.

12. The thermochemical heat pump of any of claims 1 to 11, wherein the volatile liquid solvent is water and the salt composition comprises at least one salt selected from the group formed by: ZnCl₂、NaOH、LiBr、ZnBr₂、KOH、LiCl、CaBr₂、Lil、CaCl₂、MgCl₂、NaI、Ca(NO₃)₂、Mg(NO₃)₂、NaBr、NH₄NO₃、KI、SrCl₂、NaNO₃、NaCl、KCH₃CO₂、K₂CO₃、MnCl₂、NaNO₂。

13. A method for redistributing stored thermal energy by a thermochemical approach, said method comprising:

-vaporizing the volatile liquid solvent by exchanging heat with a thermal source called a heat source (27),

-a reaction comprising the condensation of the vapour of the volatile solvent and the absorption of a salt composition to form a liquid solution, accompanied by the generation of heat, which is rejected by exchanging heat towards a thermal source called cold source (31),

characterized in that the reaction is carried out in at least one reactor, called condensation reactor (52), and comprises:

-supplying a liquid solution input of the condensation reactor (52) with a cold liquid solution from a cooling exchanger (81) adapted to be thermally associable with the cold source (31),

-supplying the condensation reactor (52) with volatile solvent vapour resulting from the vaporisation,

-supplying the cooling exchanger (81) with a hot liquid solution delivered by a liquid solution outlet of the condensation reactor (52),

-bringing the vapour supplied into the condensation reactor (52) into contact with the cold liquid solution supplied into the condensation reactor (52) so as to cause condensation of the vapour and mixing of the volatile liquid solvent thus formed by condensation with the cold liquid solution, the hot liquid solution transported by the condensation reactor resulting from the mixing,

-injecting at least one salt composition between the liquid solution output and the liquid solution input of at least one condensation reactor (52),

-adjusting the mass flow of each salt introduced into the liquid solution by injecting a salt composition between the liquid solution output and the liquid solution input of at least one condensation reactor (52).

14. The method of claim 13, wherein the adjusting comprises servoing the mass flow rate over at least one measured temperature.

15. The method of claim 13 or 14, wherein the salt composition is formed by dissolving at least one solid salt in a portion of the flow of a liquid solution comprising the liquid solution conveyed by the at least one condensing reactor (52).

Technical Field

The present invention relates to a thermochemical heat pump, in particular for redistributing stored thermal energy by a thermochemical route. The invention extends in particular to a thermal energy redistribution method implemented in such a thermochemical heat pump.

Background

The recovery and storage of thermal energy by thermochemical routes has great advantages and has been the subject of a very large amount of research and recommendations, for example, for the utilization of heat called inevitable heat (necessarily produced but lost at industrial sites and at heat production sites of urban heating networks), or for the interstaged use of solar thermal energy (see for example the paper "for the recovery by LiBr-H)₂0 absorption method study to store solar thermal energy for long term heating of homes, N' Tsoukpoe, grand boolean university, 3 months and 19 days 2012).

Known thermochemical heat pumps generally comprise a volatile solvent evaporator comprising a heat exchanger, called evaporator exchanger, thermally associated with a heat source, and a reaction device suitable for causing the condensation of the volatile solvent vapour and the absorption of the salt composition of at least one salt by the volatile liquid solvent thus formed by condensation, so as to form a liquid solution, called primary solution, accompanied by the generation of heat which is rejected towards said heat sink through the heat exchanger thermally associated with the heat sink. Such thermo-chemical heat pumps are capable of absorbing heat from a heat source (in particular for cooling said heat source) and/or transferring heat to a heat sink (in particular for reheating said heat sink). Thus, the thermochemical heat pump can be used for both heating and cooling a place or fluid.

As indicated in the above paper, the choice of each salt in the salt composition and the choice of liquid solvent is particularly elaborate and complex. Furthermore, one of the problems arising with such heat pumps is that they can be adapted well to the requirements of use, both for heating the cold source and for cooling the hot source. In particular, thermo-chemical heat pumps need to be efficient enough to bring about the required heating or cooling, and also to be able to vary the delivered thermal power according to the needs of the use.

Disclosure of Invention

The present invention aims to solve this general problem.

To this end, the invention relates to a thermochemical heat pump comprising:

-an evaporator, called solvent evaporator, comprising:

a container of a volatile liquid solvent,

-a heat exchanger, called evaporator exchanger, adapted to be thermally associable with a thermal source, called heat source, and comprising a circuit with a volatile liquid solvent input coupled with a container of said volatile liquid solvent,

-a volatile solvent vapour output, the solvent evaporator being adapted to be transferable volatile solvent vapour vaporized under the action of heat from the heat source,

-a reaction device comprising:

an inlet for volatile solvent vapor,

o at least one source of a composition, referred to as a salt composition, comprising at least one salt dissolvable in the volatile liquid solvent,

at least one heat exchanger, called cooling exchanger, adapted to be thermally associable with a thermal source, called cold source,

-the vapour output of the solvent evaporator is coupled with the vapour input of the reaction device,

-the reaction device is adapted to cause condensation of the volatile solvent vapour and absorption of the salt composition to form a liquid solution, which is accompanied by generation of heat, which is rejected by the cooling exchanger towards the heat sink,

characterized in that the reaction device comprises:

-at least one reactor, called condensation reactor, comprising:

a liquid solution input port coupled with a cold liquid solution output port of the cooling exchanger,

an inlet for volatile solvent vapor,

a liquid solution output port coupled with a hot liquid solution input port of the cooling exchanger,

-the condensation reactor is adapted to bring the vapour supplied by the vapour input port into contact with the cold liquid solution delivered to the liquid solution input port, so as to cause condensation of the vapour and mixing of the volatile liquid solvent thus formed by condensation with the cold liquid solution, resulting from this mixing in a hot liquid solution delivered to the liquid solution output port of the condensation reactor,

-at least one salt composition injection between the liquid solution output and the liquid solution input of at least one (in particular each) condensing reactor,

-a regulating device for regulating the mass flow of each salt introduced into the liquid solution by at least one salt composition injection between the liquid solution output and the liquid solution input of at least one condensation reactor.

The condensation reactor has a recirculation of the liquid solution, with injection of the salt composition and adjustment of the mass flow rate for each salt introduced by this injection, the use of such a condensation reactor enables simple adjustment of the operating concentration of the liquid solution formed by the reaction device. However, the inventors have determined that this concentration enforces a theoretical temperature difference between the evaporation temperature of the solvent and the temperature of the hot liquid solution at the output of the condensation reactor, which is a factor affecting the thermal power delivered by the heat pump. More specifically, the theoretical temperature difference that can be obtained between the solvent evaporator and the condensation reactor depends inter alia on the choice of liquid solvent, the choice of each salt of the salt composition and the choice of the operating concentration.

In particular, the maximum theoretical temperature difference is itself determined by the maximum possible concentration of the liquid solution, which depends on the choice of each salt for the salt composition and on the choice of the liquid solvent. Thus, in the thermochemical heat pump according to the invention, it is sufficient to choose only the salt composition and the liquid solvent in order to obtain the maximum concentration that determines the maximum theoretical temperature difference that is sufficient to satisfy the maximum requirement for using thermal power. In this maximized range, the thermal power delivered by the heat pump according to the invention can be adjusted simply by adjusting the mass flow of each salt resulting from the injection of the salt composition between the output and the input of the at least one condensation reactor.

A heat pump according to the invention may comprise a single cooling exchanger thermally associated with a single cold source, or a plurality of heat exchangers thermally associated with different multiple cold sources.

The heat pump according to the invention may comprise a single condensation reactor, or different condensation reactors (e.g. arranged in parallel or in cascade).

The heat pump according to the invention may comprise a single salt composition injection between the output and the input of each condensation reactor, or different multiple injections of the same salt composition or different salt compositions between the output and the input of each condensation reactor.

The thermochemical heat pump according to the invention can comprise a single source of salt composition, or different sources of the same salt composition, or different sources of a plurality of different salt compositions (different salt compositions being distinguished from each other according to the nature of at least one salt and/or the proportions thereof).

Any embodiment of a source of salt composition may be considered in a heat pump according to the present invention. Thus, in some advantageous embodiments, the thermochemical heat pump according to the invention comprises, as source of the salt composition, at least one dissolution reactor suitable for enabling the dissolution of at least one (in particular each) solid salt of said salt composition in an unsaturated liquid solution of said liquid solvent, comprising at least one output port for delivering a flow of a concentrated liquid solution forming said salt composition. Thus, in these embodiments, the salt composition is formed in the heat pump according to the invention on the basis of at least one solid salt. The heat pump according to the invention may comprise a single dissolution reactor (especially when the salt composition comprises a single salt); or a plurality of dissolution reactors, e.g. for dissolving different multiple salts and/or according to different concentrations and/or based on different unsaturated liquid solutions.

The use of such a dissolution reactor is particularly advantageous in the case where the thermochemical heat pump according to the invention is used to redistribute the thermal energy previously recovered by the thermochemical route (by decomposing the liquid solution of at least one salt into a solid composition of at least one salt and in the form of a volatile liquid solvent). In fact, it is sufficient to place the solid composition in the dissolution reactor and the liquid solvent in the solvent evaporator only to redistribute the heat energy thus stored thermochemically to the cold source and/or to the hot source.

In some advantageous embodiments of the heat pump according to the invention, at least one (in particular each) dissolution reactor is adapted to convey the salt composition in the form of a saturated liquid solution.

Moreover, in some advantageous embodiments according to the present invention, at least one salt composition injection (in particular through a pipe) is coupled to at least one outlet of the condensation reactor. More specifically, in some particular embodiments, the salt composition injection is formed by an injection pipe coupling at least one outlet of the dissolution reactor with a pipe called common pipe coupled with the liquid solution outlet of the condensation reactor. It is also possible in a variant or in combination to provide the injection of the salt composition upstream of said liquid solution input of the condensation reactor.

The heat pump according to the invention advantageously comprises at least one pump for driving the liquid solution. In particular, in some advantageous embodiments according to the invention, said common conduit comprises a pump downstream of the injection of said salt composition. The pump is thus able to cause mixing in the common conduit of the salt composition from the dissolution reactor with the liquid solution from the condensation reactor.

In some particularly advantageous embodiments of the thermochemical heat pump according to the invention, at least one (in particular each) dissolution reactor comprises an unsaturated liquid solution inlet, said unsaturated liquid solution inlet being coupled with said common pipe by a supply pipe, said supply pipe comprising a controlled valve for adjusting the flow of unsaturated liquid solution delivered to the inlet of said dissolution reactor. Thus, the salt composition is formed from a concentrated liquid solution obtained by dissolving at least one solid salt in the flow of one of the portions of diluted liquid solution extracted from the output of the condensation reactor. Also, preferably, the supply conduit of the dissolution reactor is coupled to the common conduit downstream of the pump. The pump is therefore also able to supply the dissolution reactor, which makes it possible to avoid the addition of such a pump, the cost of which is relatively high in view of the corrosiveness of the salt solution. Advantageously and according to the invention, said adjusting means are adapted to control each controlled valve of the supply conduit of the dissolution reactor, that is to say this adjustment of the mass flow rate of each salt in the liquid solution introduced between the output and input of the condensation reactor is carried out by adjusting the flow rate of the unsaturated liquid solution supplied to the input of the dissolution reactor.

The adjustment device of the heat pump according to the invention can involve all variants. In particular, the adjustment device may be a manual adjustment device with or without information technology assistance, or conversely an automatic adjustment device preferably based on at least one set value defined by the user. Thus, in particular, the adjusting means may comprise at least one closed-loop servo (assisted servo) or open-loop servo, such as at least one proportional and/or derivative proportional and/or integral derivative Proportional (PID) adjuster or others.

In particular, in some advantageous embodiments of the thermo-chemical heat pump according to the present invention, said adjustment means comprise at least one servo adapted to deliver a control signal as a function of at least one temperature value measured in said thermo-chemical heat pump.

In some advantageous embodiments, the thermochemical heat pump according to the invention comprises a temperature sensor of the cold liquid solution at the output of each cooling exchanger, and the regulation means are suitable for servo-controlling the flow delivered by the controlled valve of the supply conduit of at least one dissolution reactor as a function of the temperature of the cold liquid solution measured by at least one such temperature sensor. This adjustment of the mass flow rate of the introduced salt, which can adjust the operating concentration, can therefore be performed without measuring or knowing the actual value of the operating concentration, can be performed only by means of a servo-action on the measured temperature at the output of the cooling exchanger on the flow rate delivered by the controlled valve of the supply conduit of at least one dissolution reactor (which determines the flow rate of the salt composition injected from this dissolution reactor). Thus, if the measured temperature at the output of the cooling exchanger is too low, the servo opens the controlled valve to increase the flow of the salt composition introduced into the liquid solution. Conversely, if the measured temperature at the output of the cooling exchanger is too high, the servo closes the controlled valve to reduce the flow of the salt composition introduced into the liquid solution. This servo on the controlled valve of the supply line of the dissolution reactor thus enables a simple adjustment of the theoretical temperature difference of the heat pump according to the invention.

Furthermore, in some embodiments of the heat pump according to the invention, the common conduit is coupled to the hot liquid solution input of each cooling exchanger by a recirculation conduit comprising a controlled valve for regulating the flow of hot liquid solution delivered to the cooling exchanger and thus the flow of cold liquid solution delivered to the input of each condensation reactor coupled to the liquid solution output of the cooling exchanger. Also, preferably, the recirculation conduit is coupled with the common conduit downstream of the pump. The pump is therefore also able to supply each cooling exchanger, which makes it possible to avoid the addition of such a pump, the cost of which is relatively high in view of the corrosiveness of the saline solution.

Such a controlled valve of the recirculation conduit is therefore capable of adjusting the total flow of liquid solution circulating through each condensation reactor and therefore the thermal power delivered by the heat pump according to the invention. The adjustment may be carried out completely manually or, conversely, by means of an automatic system comprising at least one servo (for example by thermostatic means of a heat source and/or cold source), based on at least one set point defined by the user.

The invention applies to thermochemical heat pumps of any nature, the general operating conditions of which can involve a large number of variants depending on the application and choice for the liquid solvent and each salt of the salt composition. Thus, in some embodiments according to the invention, each evaporator, the reaction device, each conduit through which the vapour flows and each conduit through which the liquid solution flows are under a negative pressure (en d pressure gas de tiesgaz) under a third gas vacuum. In particular, each evaporator, each condensation reactor, each conduit coupling the evaporator with the condensation reactor, each dissolution reactor and each other conduit in which the liquid solution circulates are at a negative pressure under a third gas vacuum. In particular, such an implementation of the negative pressure under vacuum of the third gas enables vaporization to be carried out at low temperatures.

As noted above, the thermochemical heat pump according to the invention can be used with any volatile liquid solvent and any salt composition, depending on the application and the requirements. Thus, in some advantageous embodiments, the volatile liquid solvent is water, and the salt composition comprises at least one salt selected from the group consisting of: ZnCl₂、NaOH、LiBr、ZnBr₂、KOH、LiCl、CaBr₂、Lil、CaCl₂、MgCl₂、NaI、Ca(NO₃)₂、Mg(NO₃)₂、NaBr、NH₄NO₃、KI、SrCl₂、NaNO₃、NaCl、KCH₃CO₂、K₂CO₃、MnCl₂、NaNO₂。

In particular, the present invention relates to a thermochemical heat pump comprising:

-an evaporator, called solvent evaporator, comprising:

a container of a volatile liquid solvent,

-a heat exchanger, called evaporator exchanger, adapted to be thermally associable with a thermal source, called heat source, and comprising a circuit with a volatile liquid solvent input coupled with a container of said volatile liquid solvent,

-a volatile solvent vapour output, the solvent evaporator being adapted to be transferable volatile solvent vapour vaporized under the action of heat from the heat source,

a heat exchanger, called cooling exchanger, adapted to be thermally associable with a thermal source, called cold source,

-a condensation reactor comprising:

a liquid solution input port coupled with a cold liquid solution output port of the cooling exchanger,

an inlet for volatile solvent vapor,

a liquid solution output port coupled with a hot liquid solution input port of the cooling exchanger,

-a conduit coupling the vapor output port of the solvent vaporizer with the vapor input port of the condensation reactor,

-the condensing reactor is adapted to bring the vapour supplied by the vapour input into contact with the cold liquid solution delivered to the liquid solution input of the condensing reactor, so as to cause condensation of the vapour and mixing of the volatile liquid solvent thus formed by condensation with the cold liquid solution, resulting from this mixing in a hot liquid solution delivered to the liquid solution output of the condensing reactor,

-at least one source of a composition, called salt composition, comprising at least one salt soluble in the volatile liquid solvent,

-at least one salt composition injection between the liquid solution output and the liquid solution input of the condensation reactor,

-a regulating device for regulating the mass flow of the salt composition injected between the liquid solution output and the liquid solution input of the condensation reactor.

The invention also extends to a method implemented in a thermochemical heat pump according to the invention.

Accordingly, the present invention relates to a method for redistributing stored thermal energy by a thermochemical route, said method comprising:

vaporizing the volatile liquid solvent by exchanging heat with a thermal source called a heat source,

a reaction comprising the condensation of the vapour of the volatile solvent and the absorption of a salt composition to form a liquid solution, accompanied by the generation of heat, which is rejected by exchanging heat towards a thermal source called cold source,

characterized in that the reaction is carried out in at least one reactor, called condensation reactor, and comprises:

-supplying the liquid solution input of the condensation reactor with a cold liquid solution from a cooling exchanger adapted to be thermally associable with the cold source,

-supplying the condensation reactor with volatile solvent vapour resulting from the vaporization,

-supplying the cooling exchanger with a hot liquid solution delivered by a liquid solution outlet of the condensing reactor,

-bringing the vapour supplied to the condensation reactor into contact with the cold liquid solution supplied to the condensation reactor, so as to cause condensation of the vapour and mixing of the volatile liquid solvent thus formed by condensation with the cold liquid solution, resulting from this mixing in the hot liquid solution delivered by the condensation reactor,

-injecting at least one salt composition between the liquid solution output and the liquid solution input of at least one (in particular each) condensation reactor,

-adjusting the mass flow of each salt introduced into the liquid solution by injecting a salt composition between the liquid solution output and the liquid solution input of at least one (in particular each) condensation reactor.

In particular, in some embodiments of the method according to the invention, said adjusting comprises a servo of said mass flow over at least one measured temperature (in particular the measured temperature of the cold liquid solution supplied into said condensation reactor).

Furthermore, in some embodiments of the method according to the present invention, the salt composition is formed by dissolving at least one solid salt in a part of the flow of the liquid solution comprising the liquid solution transported by the at least one (in particular each) condensation reactor. The salt composition is thus a concentrated liquid solution, especially a saturated liquid solution.

In some embodiments of the method according to the invention, said adjusting thereby comprises a servo of the injected flow rate of said salt composition. In a variant or in combination, the adjustment can also be carried out by a servo to the concentration of the injected salt composition.

The invention also relates to a thermochemical heat pump suitable for implementing the thermal energy redistribution method according to the invention.

The invention also relates to a thermochemical heat pump and a thermal energy redistribution method, whose features, in combination or not, adopt all or part of the structural or functional features mentioned above or below. Whatever the formal statement given, the different structural or functional features mentioned above or below are not to be considered as being in close or inseparable relation with each other, unless expressly stated otherwise, and the invention may relate to only a single one of these features, or only a part of one of these features, or any grouping, combination or juxtaposition of all or part of these features.

Drawings

Other objects, features and advantages of the present invention will become more apparent upon reading the following detailed description, given in a non-limiting manner, and the accompanying drawings, in which:

figure 1 is a schematic view showing a first possible embodiment of a thermochemical heat pump according to the invention,

FIG. 2 is the Othmer diagram of an aqueous sodium hydroxide solution,

figure 3 is a schematic view showing a second possible embodiment of the thermochemical heat pump according to the invention,

fig. 4 is a schematic diagram showing the heat pump of fig. 3 in different states.

Detailed Description

The thermochemical heat pump 15 according to the invention, shown in figure 1, comprises:

an evaporator, called solvent evaporator 26, which is under negative pressure under a third gas vacuum, in which a pure liquid solvent 28 is supplied (for example by a vehicle from a recovery station), the solvent evaporator 26 being thermally associated with a cold medium 27 acting as a heat source, so as to be able to absorb, by means of the solvent evaporator 26, the heat drawn from the heat source 27, which heat is able to vaporize the liquid solvent 28 in the solvent evaporator 26.

A reaction device 29, which is at negative pressure under third gas vacuum and is coupled with the output of the solvent evaporator 26 by a duct 30 at negative pressure under third gas vacuum, in order to receive the vapour generated by the solvent evaporator 26; the reaction device 29 is supplied with a quantity of solid composition of at least one salt (for example fed by a vehicle from a recovery station simultaneously with the pure liquid solvent); the reaction means 29 are adapted to enable, on the one hand, condensation of the liquid solvent, contacting of the liquid solvent with at least a portion of the quantity of solid composition, and dissolution of each salt in the liquid solvent of the unsaturated liquid solution to form a liquid solution having a total concentration Cf.

The reaction device 29 is thermally associated with a thermal medium 31 acting as a heat sink to transfer heat towards the heat sink under the effect of the heat generated by the condensation of the vapour on the one hand and by the dissolution of the solid composition in the liquid solvent on the other hand.

Thus, such a heat pump 15 is able to cool the heat source 27 and/or reheat the cold source 31, as the solid composition of at least one salt dissolves in the liquid forming the solvent (for the solid composition).

The solvent evaporator 26 comprises a closed container 46 containing the pure liquid solvent to be vaporized and the bottom of which communicates with a pipe 47 equipped with a pump 48 and a controlled proportioning valve 50, which is able to extract the liquid from the container 46 in order to pass it into a heat exchanger called evaporator exchanger 49, which is associated with a heat source 27, the temperature of which is higher than the temperature of the pure liquid solvent extracted from the container 46. Thereby, the liquid solvent is at least partially vaporized in the solvent evaporator 26 under the effect of the heat absorbed by the evaporator exchanger 49, the output of which is coupled with the upper part of the container 46 above the level of the liquid solvent in the container 46, which upper part of the container 46 receives the solvent thus vaporized. A temperature sensor 51 is capable of measuring the temperature of the liquid solvent vapor at the output of the evaporator exchanger 49.

The reaction apparatus 29 comprises a condensation reactor 52 in the form of a closed housing which is coupled to the upper part of the vessel 46 of the solvent evaporator 26 by a conduit 30 so that solvent vapour can be supplied from the evaporator 26. The upper part of the condensation reactor 52 comprises a trickle device 55, which is coupled to a pipe 54 supplying the liquid solution. This trickle device 55 is able to create inside the condensation reactor 52 a falling film of the liquid solution, which is in contact with the solvent vapour, thus causing the condensation of this vapour and its mixing with the liquid solution, which is accompanied by the generation of heat. Thus, the liquid solution in the lower part of the condensation reactor 52 has a lower concentration and a higher temperature than the liquid solution at the input of the condensation reactor 52. The liquid solution is withdrawn from the reactor 52 through a line 56.

The reaction device 29 also comprises a dissolution reactor 57, also in the form of a closed housing, which is adapted to be supplied with crystals of at least one solid salt 58, for example arranged on a horizontal screen and/or in a textile matrix. The dissolution reactor 57 further comprises a liquid solution supply 59 in the upper part to enable a flow of the liquid solution to contact the crystals of the solid salt 58 and dissolve the crystals of the solid salt in the liquid solution. After dissolution and heat generation, a saturated concentrated liquid solution is extracted from the lower portion of the dissolution reactor 57 through a pipe 60.

The pipes 56 and 60 for conveying the liquid solutions coming from the condensation reactor 52 and the dissolution reactor 57, respectively, merge at the input of a pump 62 into a common pipe 61 in which the liquid solutions are mixed.

A first conduit 63 comprising a controlled proportioning valve 66 couples the output of said pump 62 with a heat exchanger called cooling exchanger 81 associated with a cold source 31 and able to transfer heat from the liquid solution delivered by said pump 62 towards said cold source 31, the output of this heat exchanger 81 being used to deliver the cooled liquid solution. The cooled liquid solution is supplied to the condensation reactor 52 through a conduit 54 coupling the output of the heat exchanger 81 with the condensation reactor 52. The temperature sensor 53 is able to measure the temperature of the liquid solution circulating in the conduit 54 between the exchanger 81 and the condensation reactor 52.

A second conduit 64 comprising a controlled proportioning valve 67 couples the output of the pump 62 with the supply 59 of the dissolution reactor 57.

As the solvent extracted from the container 46 of the solvent evaporator 26 evaporates, the reaction device 29 produces a volume of liquid solution, called primary solution, in the common conduit 61, having a total operating concentration Cf. This primary solution can be reused in a subsequent thermal energy recovery stage, for example, after being transported to a recovery site of the necessary heat (the heat that must be generated and generally lost at the industrial site). This primary solution may be transferred to a storage container (not shown in fig. 1) which is supplied according to the production of the primary solution from the common pipe 61. In a variation, the liquid solution may be withdrawn at the output of the condensation reactor 52, so that the liquid solution is stored in a storage vessel for later use.

In the example shown, the robot 85 is a device coupled to the temperature sensors 51, 53 to receive measurement signals therefrom and to the valves 66, 67 to control them, which robot 85 is programmed according to a servo.

The control of the valve 67 enables adjustment of the mass flow of the salt composition introduced into the liquid solution through the pipe 60 at the output of the dissolution reactor 57 and thus adjustment of the total operating concentration Cf of the heat pump. This total concentration Cf determines the theoretical temperature difference brought about by the liquid solution.

Figure 2 shows a logarithmic Othmer plot of the vapor pressure of aqueous sodium hydroxide solution as a function of temperature. Curve C1 is the crystallization curve. The different lines extending from this crystallization curve correspond to different mass concentrations of the aqueous sodium hydroxide solution, and the line L1 at the leftmost side corresponds to pure water. As can be seen, the theoretical temperature difference Δ T provided by a 50% aqueous solution of sodium hydroxide is 335K-280K ═ 55K, for example, as compared to 280K (7 ℃) of pure water. For a 70% aqueous sodium hydroxide solution, the theoretical temperature difference is 120K. Thus, with sodium hydroxide, a larger theoretical temperature difference can be obtained.

If a heat pump is used to heat the cold source 31 to a predetermined set temperature, the temperature of the heat source 27 and the temperature of the solvent in the evaporator 26 are predetermined (or deemed to be such), and the value of the theoretical temperature difference determines the temperature of the liquid solution at the output of the condensation reactor 52 and hence at the input of the cooling exchanger 81.

By increasing this temperature of the liquid solution at the input of the cooling exchanger 81, the thermal power supplied to the cold source 31 is increased at a constant flow rate. The temperature at the output of the cooling exchanger 81 (by the efficiency coefficient of the cooling exchanger 81 in the vicinity) measured by the sensor 53 represents the temperature of the cold source 31. If the measured temperature is below the set temperature, the robot 85 increases the opening of the valve 67 to increase the mass flow of the injected salt composition and thus increase the temperature of the liquid solution at the input of the cooling exchanger 81. Conversely, if the measured temperature is higher than the set temperature, the automatic device 85 reduces the opening of the valve 67 to reduce the mass flow rate of the injected salt composition and therefore reduce the temperature of the liquid solution at the input of the cooling exchanger 81.

The control law for increasing or decreasing the opening of the valve 67 as a function of the difference between the temperature measured by the sensor 53 and the set temperature may involve all suitable variants: in particular, said control law relates to a proportional control law and/or a derivative proportional control law and/or an integral derivative Proportional (PID) control law or others.

It is noted that the cooling exchanger 81 comprises a secondary circuit thermally associated with the cold source 31, which is isolated from the main circuit of the exchanger 81 forming part of the heat pump, the temperature sensor 53 being replaceable by a temperature sensor at the output of the secondary circuit in order to bring about a more precise adjustment of the set temperature of the cold source 31.

In addition, it is noted that the temperature of the liquid solution at the input of the cooling exchanger 81 needs to be higher than the set temperature that the cold source 31 needs to reach. For this reason, therefore, it is appropriate to select the salt composition so as to be able to satisfy this condition. In particular, in practice, the use of sodium hydroxide enables this condition to be satisfied by a simple servo on the temperature measured by the sensor 53, since, as mentioned above, the theoretical temperature difference that can be obtained by sodium hydroxide can be very large and can reach 150 ℃.

Control of the valve 66 enables adjustment of the flow rate of the liquid solution recirculated in the condensation reactor 52. Preferably, the valve 66 is in a normal operating condition and is maximally open. However, if the required power is reduced, the valve 66 may be closed to immediately reduce the thermal power provided by the heat pump.

The robot is also coupled with the pumps 62, 48 and programmed to control them to be put into operation or stopped, and with the valve 50, so as to be able to adjust the flow rate of the liquid solvent vaporized in the evaporator 26.

If a heat pump is used to cool the heat source 27 to a predetermined set temperature, the temperature of the cold source 31 and the temperature of the liquid solution at the output of the condensation reactor 52 are predetermined (or deemed to be) and the value of the theoretical temperature difference determines the temperature of the liquid solvent in the evaporator 26 at the input of the evaporator exchanger 49.

By reducing this temperature of the liquid solvent at the input of the evaporator exchanger 49 at a constant flow rate, the thermal power provided by the heat source 27 to the evaporator exchanger 49 is increased. If the vapor temperature at the output of the evaporator exchanger 49, as measured by the sensor 51, is below the set temperature, the robot 85 reduces the opening of the valve 67 to reduce the mass flow of the injected salt composition and thereby increase the temperature of the liquid solvent at the input of the evaporator exchanger 49. Conversely, if the temperature measured by the sensor 51 is higher than the set temperature, the robot 85 increases the opening of the valve 67 to increase the mass flow of the injected salt composition and thus decrease the temperature of the liquid solvent at the input of the evaporator exchanger 49.

The control law for increasing or decreasing the opening of the valve 67 as a function of the difference between the temperature measured by the sensor 51 and the set temperature may involve all suitable variants: in particular, said control law relates to a proportional control law and/or a derivative proportional control law and/or an integral derivative Proportional (PID) control law or others.

In addition, it is noted that the temperature of the liquid solvent at the input of the evaporator exchanger 49 needs to be lower than the set temperature that the heat source 27 needs to reach. For this reason, therefore, it is appropriate to select the salt composition so as to be able to satisfy this condition. In particular, in practice, the use of sodium hydroxide enables this condition to be satisfied by a simple servo on the temperature measured by the sensor 51, since, as mentioned above, the theoretical temperature difference that can be obtained by sodium hydroxide can be very large and can reach 150 ℃.

The control of the valve 50 at the input of the evaporator exchanger 49 enables the regulation of the flow rate of the liquid solvent circulating in this evaporator exchanger 49. Preferably, the valve 50 is in a normal operating condition and is maximally open. However, if the required power is reduced, the valve 50 may be closed to immediately reduce the thermal power provided by the heat pump.

As mentioned above in relation to the cold source 31, the temperature sensor 51 may be replaced or supplemented by a temperature sensor at the output of the secondary circuit of the evaporator exchanger 49 and/or by a temperature sensor of the heat source 27.

In the embodiment shown on fig. 3 and 4, the primary solution conveyed by the reaction device 29 is next subjected to a partial separation step during which it is partially de-concentrated. To this end, the primary solution is supplied to the input of a recrystallization device 34 under negative pressure under vacuum of a third gas, which comprises heat exchange means associated with the evaporator 26, so as to cool the primary solution to a temperature sufficiently low by the cold generated by the evaporator 26 to cause the partial recrystallization of at least one salt comprised in the primary solution.

The recrystallization device 34 produces: on the one hand, a liquid solution, called a deconcentrated solution, having a total concentration Cd that is non-zero and less than Cf and that can be stored, for example, in a container 36 at negative pressure under vacuum of a third gas; in another aspect, an amount of at least one salt is a solid composition referred to as recrystallized composition 77.

The recrystallized composition 77 may be recycled in the reaction apparatus 29 to form the primary solution.

As can be seen, the reaction device 29 operates with a total concentration Cf, which is the concentration of the primary solution 32 produced and defines the maximum temperature difference that can be produced between the reaction device 29 and the evaporator 26 and thus between the heat source 27 and the cold source 31.

Conversely, if the recrystallized composition 77 does not include a solvent, the deconcentrated solution includes the same amount of liquid solvent as the primary solution, but with a concentration Cd lower than Cf.

Thus, the reaction apparatus 29 also comprises a partial recrystallization reactor 72 in the form of a closed casing comprising a heat exchanger 74 comprising a cold circuit supplied with cold liquid solvent through a conduit 75 coupled downstream of the pump 48 at the output of the evaporator 26 by means of a controlled proportioning valve 76. After passing to this cold circuit, which heats up internally, the liquid solvent is recycled in the container 46 of the evaporator 26 through the pipe 78. The partial recrystallization reactor 72 also includes a liquid solution supply 73 in the upper portion to enable a stream of the liquid solution to be contacted with a heat exchanger 74 (or into a hot loop of the heat exchanger), whereby the liquid solution is cooled to a temperature sufficiently low to partially recrystallize. The crystals 77 thus formed are recovered in the lower part of the partial recrystallization reactor 72 (e.g. on the screen or in the fabric matrix of the partial recrystallization reactor). The de-concentrated liquid solution thus formed in the partial recrystallization reactor 72 is withdrawn from the lower part of said partial recrystallization reactor through a line 82 comprising a controlled valve 83, this line 82 leading to the container 36 in which the de-concentrated liquid solution is stored.

A conduit 79 comprising a controlled proportioning valve 80 also couples the lower part of the partial recrystallization reactor 72 downstream of the valve 69 at the output of the dissolution reactor 57 or with a common conduit 61 upstream of the pump 62 so that the liquid solution from the partial recrystallization reactor 72 can be mixed with the liquid solution from the condensation reactor 52.

The conduit 60 coupling the dissolution reactor 57 with the common conduit 61 comprises a controlled proportioning valve 69. A third conduit 65 comprising a proportional supply valve 68 couples the output of the pump 62 to a supply 73 of the partial recrystallization reactor 72.

The automatic device 85 is capable of adjusting the temperature of the partial recrystallization reactor 72 by adjusting the flow rate of the liquid solvent supplied into the heat exchanger 74, by means of a temperature sensor (not shown) whose signal is transmitted to the automatic device 85, by controlling the opening degree of the valve 76 in accordance with the measured temperature in the partial recrystallization reactor 72.

The automatic device 85 is also capable of adjusting the level of the liquid solution in the reaction device 29 in accordance with the supply of the liquid solvent from the evaporator 26 by controlling the supply flow rate of the partial recrystallization reactor 72 by controlling the opening degree of the supply valve 68. To this end, at least one level sensor (not shown) of the liquid solution is advantageously provided in the reaction device 29, the automatic means 85 receiving the signal transmitted by each level sensor and being adapted to maintain the level.

In the situation shown in fig. 3, the workstation is able to gradually dissolve the crystals 58, corresponding to the composition supplied by the vehicle for example, in an amount of pure liquid solvent, corresponding to the amount supplied by the vehicle for example, and incorporated into the container 46 of the evaporator 26. The vaporization of the liquid solvent in the evaporator 26 generates the cold used in the exchanger 74 to partially recrystallize at least a portion of the liquid solution in the partial recrystallization reactor 72, which produces a de-concentrated solution that accumulates in the partial recrystallization reactor 72 and crystals 77 of the at least one solid salt so formed. The volume of liquid solution supplied to the partial recrystallization reactor 72 advantageously corresponds to the volume of liquid solvent reintroduced from the evaporator 26, for example by the condensation reactor 52.

In this state, the valves 50, 66, 67, 68, 69, 76 are open, and the valve 80 is closed. The liquid solution formed in the common conduit 61 is a primary solution having a concentration Cf whose value depends on the respective state of the valves 66 and 67, so as to be able to regulate the flow rate and therefore the thermal power delivered to the condensation reactor 52 and the dissolution reactor 57, respectively, according to the needs of the heat source 27 and/or of the cold source 31.

Once all the crystals 58 are dissolved in the dissolution reactor 57 and/or the partial recrystallization reactor 52 reaches the maximum capacity of the deconcentrated solution, the deconcentrated solution is drained into the vessel 36 through the pipe 82 by opening the controlled valve 83.

In the state shown in fig. 4, the common pipe 61 is not supplied from the dissolution reactor 57, but is supplied from the partial recrystallization reactor 72, which thus functions as a dissolution reactor. In this state, the valve 69 is closed, and the valve 80 is opened. The liquid solution formed in the common pipe 61 is a primary solution whose concentration Cf depends on the respective states of the valves 66 and 68 so as to be able to regulate the flow rates delivered to the condensation reactor 52 and the partial recrystallization reactor 72, respectively. Thus, the crystals 77 formed during the partial recrystallization can be immediately recycled to form the primary solution until these crystals 77 are depleted.

The different reactors 52, 57, 72, the container 46 of the evaporator, the heat exchangers 49, 81, the storage container 36 of the deconcentrated solution and the different conduits that connect them to each other are under negative pressure under a third gas vacuum, that is to say, communicate (according to the state of the controlled valves) to form the same closed housing in which all the gases are evacuated by a vacuum pump (not shown) before the plant is put into operation.

In the embodiment shown in fig. 3, the automatic device 85 is also coupled to the valve 68 so as to be able to regulate the flow rate of the liquid solution supplied to the input of the partial recrystallization reactor 72, and to the valve 76 so as to be able to regulate the flow rate of the liquid solvent capable of cooling the partial recrystallization reactor 72. The automation 85 is also coupled to the valves 69, 80 in order to be able to change the state of the heat pump from the state shown in fig. 3 to the state shown in fig. 4 and vice versa.

The different controlled valves may for example be proportional solenoid valves controlled by automatic means, programmed in particular as described above to carry out the technical functions mentioned above, in particular according to closed or open loop suitable servos, and based on measurement sensors, in particular temperature sensors and/or thermostats and/or level sensors in the container or reactor and/or presence detection sensors of the solid composition in the reactor or others.

The invention may be directed to numerous variations and applications in addition to those described above. In particular, of course, the different structural and/or functional features of each of the above-described embodiments should not be regarded as combined and/or closely related to each other, but rather as a simple juxtaposition, unless explicitly stated otherwise. Furthermore, structural or functional features in different embodiments described above may relate to all or part of any different juxtaposition or any different combination.

For example, the adjustment of the mass flow rate of the injected salt composition may be carried out completely manually by acting on the supply valve 67 of the dissolution reactor 57; the heat pump may not be placed at a negative pressure under vacuum of the third gas, but at a higher pressure (if compatible with the associated vaporization phenomena, taking into account the thermal characteristics of the heat source associated with the evaporator), while including a neutral gas (e.g., air or otherwise). In addition, the different condensation devices, dissolution devices, heat exchange devices … … may involve all structural modifications and optimizations known per se in chemical engineering in order to exert the above mentioned technical functions.

The supply pipe of the dissolution reactor 57 may not be coupled to the common pipe 61 but to the output of the cooling exchanger 81 in order to be supplied with the cooled liquid solution. The corresponding valve 67 is thus arranged downstream of said cooling exchanger 81. Likewise, the supply conduit of the recrystallization reactor 72 may not be coupled to the common conduit 61, but to the output of the cooling exchanger 81, in order to be supplied with the cooled liquid solution. The respective valve 68 is thus positioned downstream of said cooling exchanger 81.