AU2021348337A1

AU2021348337A1 - Combined heat generation and water desalination plant

Info

Publication number: AU2021348337A1
Application number: AU2021348337A
Authority: AU
Inventors: Anthony Delahaye; Laurence Fournaison; Romuald HUNLEDE
Original assignee: Institut National De Recherche Pour L'agriculture L'alimentation Et Lenvironnement; Institut National de Recherche pour lAgriculture lAlimentation et lEnvironnement
Current assignee: Institut National de Recherche pour lAgriculture lAlimentation et lEnvironnement
Priority date: 2020-09-28
Filing date: 2021-09-28
Publication date: 2023-06-08
Also published as: IL301363A; EP4217317A1; FR3114642B1; WO2022064161A1; AU2021348337A9; FR3114642A1

Abstract

The invention relates to a combined heat generation and water desalination plant (10) comprising: - a slurry-ice generator (20) configured to generate slurry ice from water coming from the water supply system (12), the slurry containing ice crystals and a residual liquid, - a separation system (24) configured to separate the ice crystals from the residual liquid toward a first outlet (26) and a second outlet (28) respectively, - a precooling system (42) for precooling the water supplied to the slurry-ice generator (20), - an exchanger system (36) exchanging heat energy with at least one receiver (38) so as to exchange the heat energy from the ice crystals or from the residual liquid with said at least one receiver (38), desalinated water being obtained from the melting of the ice crystals.

Description

Description Title of the invention: COMBINED HEAT GENERATION AND WATER DESALINATION PLANT

[0001] The present invention relates to the field of the desalination of water that is to be purified, notably seawater or brackish water.

[0002] In particular, the invention relates to a combined plant for the generation of heat energy and the desalination of water.

[0003] The solutions in most widespread use at the present time for the desalination of water are distillation and reverse osmosis.

[0004] Distillation consists in raising to boiling point the temperature of the water that is to be purified and in collecting the water vapor thus produced. This water vapor is then condensed to obtain water of which the salt concentration is lower. The major disadvantage with this desalination solution is that it leads to a high energy consumption rendering this type of solution ill-suited to isolated locations where the supply of electrical energy is problematical.

[0005] Reverse osmosis consists in filtering out the salt crystals or impurities contained in the water that is to be purified using membranes the pores of which allow water molecules to pass but hold back these salt crystals or these impurities. This type of plant requires less energy for purifying the water, approximately 3.7 Wh/m 3 as opposed to 15 Wh/m 3 for distillation plants. However, this type of plant requires a great deal of maintenance, notably because of the deterioration of the membranes.

[0006] As a result, plants using reverse osmosis or distillation are very expensive and/or limited in efficiency and are often aimed at large-scale applications. ?5 [0007] There is also a freeze desalination solution that works by creating ice crystals of a size that makes it possible to reduce the probability of trapping impurities, notably salt crystals, inside the ice crystals formed. The ice crystals are separated from the residual water which contains a high concentration of salt, and then heated to obtain purified water.

[0008] Freeze desalination solutions require little maintenance and have a modest energy consumption in comparison with the other desalination solutions.

However, this solution is not effective enough in its present state, and is unable to yield satisfactory salinity levels.

[0009] Elsewhere, document DE-2937575 discloses a centrifugal water desalination plant.

[0010] However, in certain locations, the demand for purified water may be accompanied by a demand for the generation of cold. What is meant by the generation of cold is the cooling of a place or a plant. By way of example, a seaside hotel complex generally needs purified water but also requires refrigeration energy, notably in order to provide an air conditioning system.

[0011] When the supply of electrical energy is problematical or there is a desire to reduce energy consumption, it is particularly advantageous to be able to combine these two demands into a single plant. Now, most existing plants are devoted to desalination alone. Systems involving the cogeneration of refrigeration energy and purified water exist, but their energy efficiency is unsatisfactory, rendering them somewhat unattractive.

[0012] There is therefore a need for an improved combined plant for the generation of heat energy and the desalination of water with better energy efficiency.

[0013] In order to do that, the invention proposes a combined plant for the generation of heat energy and the desalination of water, the plant comprising: - a water supply system; - an ice slurry generator in fluidic communication with the water supply system and configured to generate an ice slurry from water from the water supply system, the slurry containing ice crystals and a residual liquid, - a separation system in fluidic communication with the ice slurry generator and configured to separate the ice crystals from the residual liquid toward a first outlet and a second outlet respectively, - a precooling system precooling the water supplied to the ice slurry generator, the precooling system comprising a precooling duct in fluidic communication with the first outlet of the separation system so as to allow precooling of the water supplied to the generator using the ice crystals, - desalinated water being obtained from the melting of the ice crystals. In particular, the plant may comprise a desalinated water distribution pipe connected to an outlet of the precooling system.

[0014] The plant makes it possible to obtain desalinated or purified water from an ice slurry generator. The ice slurry corresponds to a fluid containing ice crystals of a size smaller than 1 mm, preferably smaller than 0.5 mm, so as to obtain an ice crystal salt concentration that is far lower than in the existing freeze desalination solutions. Specifically, the size of the ice crystals within the ice slurry makes it possible to obtain purified water of far lower salinity once the ice crystals have melted.

[0015] It is thus possible to enjoy the advantages of freeze desalination while at the same time obtaining purified water of satisfactory salinity. Freeze desalination methods are notably robust solutions which require little maintenance.

[0016] The plant may comprise a heat energy exchange system exchanging heat energy with at least one receiver, the exchange system comprising at least one heat exchanger in fluidic communication with at least one from among the precooling duct and the second outlet of the separation system so as to exchange heat energy coming respectively from the ice crystals or from the residual fluid with said at least one receiver, the heat exchanger being downstream of the precooling system. ?0 [0017] Freeze desalination solutions make it possible to recover heat energy from the ice slurry and transfer it to a receiver, such as air conditioning plants or food or equipment preservation plants. It is thus possible to reduce the energy losses incurred by the desalination of the water and direct this heat energy to another application. ?5 [0018] In addition, ice slurry is a fluid that allows effective conservation of heat energy. This desalination solution is thus particularly well suited to storage.

[0019] This storage possibility is particularly advantageous because it makes it possible to produce ice crystals at a time at which conditions are preferential, and distribute this heat energy later when a demand is identified. This storage therefore allows far more flexible and optimal operation of the plant.

[0020] When there are significant constraints on the supply of electrical energy, notably when accumulator batteries are used for powering the plant, it is thus possible to optimize the ice slurry generation against the demands for purified water and for heat energy.

[0021] By way of example, when the plant is supplied with electrical power via a solar energy source, it is thus possible to produce the ice slurry during the daytime when the accumulator batteries are being strongly charged, and to distribute all or some of this ice slurry by night, in the form of purified water or heat energy.

[0022] In addition, the use of a precooling system using heat energy from the ice slurry to precool the water also makes it possible to reduce the energy consumption of the plant.

[0023] What is thus obtained is a plant the electricity consumption of which has been greatly improved and rationalized in order to meet an existing demand for heat energy. It has been determined that such a plant supplied with electrical energy by photovoltaic panels can be autonomous in terms of energy for a daily production of purified water in excess of 450 m 3 and a daily generation of heat energy of around 2 GW.

[0024] According to one embodiment of the plant, the supply system comprises a feed pump intended to be in fluidic communication with a seawater or brackish water source so as to supply the ice slurry generator with seawater or brackish water. ?0 [0025] The plant is thus supplied directly with seawater or brackish water. This seawater or brackish water can be withdrawn directly from a marine environment, such as an ocean.

[0026] According to one embodiment of the plant, the second outlet of the separation system is in fluidic communication with said seawater or brackish water source to allow the residual fluid to be reintroduced into the seawater or brackish water source.

[0027] According to one embodiment of the plant, the exchange system comprises at least one heat exchanger in fluidic communication with the second outlet of the separation system so as to exchange heat energy from the residual fluid with said at least one receiver, the exchange system being configured to regulate the quantity of heat energy exchanged with said at least one receiver according to a target temperature of the residual fluid downstream of said at least one heat exchanger.

[0028] It is thus possible to regulate the temperature of the residual fluid reintroduced into the water source. This is particularly advantageous when the water source is a marine environment containing flora and fauna. The fluid reintroduced into this water source may thus be at the temperature of the seawater or brackish water in this marine environment. The adverse effect on the marine environment is thus reduced.

[0029] This regulation is performed for example by regulating the flow rate of residual fluid within said at least one exchanger.

[0030] According to one embodiment of the plant, the exchange system comprises at least one heat exchanger in fluidic communication with the precooling duct so as to exchange heat energy from the ice crystals or from the desalinated water obtained by the melting of the ice crystals with said at least one receiver, the exchange system being configured to regulate the quantity of heat energy exchanged with said at least one receiver according to a target temperature of the desalinated water downstream of said at least one heat exchanger.

[0031] The plant thus makes it possible to meet the demands for desalinated water more precisely by making it possible to regulate the temperature of the desalinated water produced. This regulation is performed for example by regulating the flow rate of desalinated water inside said at least one exchanger.

[0032] According to one embodiment of the plant, this plant further comprises an ice slurry storage tank positioned between the ice slurry generator and the separation system, the storage tank being configured to regulate the supply of ice slurry to the separation system.

[0033] Storing the ice slurry allows better optimized operation of the plant by allowing the desalinated water and the heat energy to be distributed at a time subsequent to the production of the ice slurry.

[0034] According to one embodiment of the plant wherein the separation system is a centrifugal separation system. According to a preferred embodiment, the separation system may comprise a first separation system being able to be selected from among one of the systems that are a first centrifugal system or a

Btichner funnel vacuum filtration system or an Archimedean pressure filtration system, this first separation system supplying in fluidic communication a second centrifugal separation system.

[0035] According to one embodiment of the plant, the separation system is positioned above the precooling system and configured so that the separated ice crystals are fed to the precooling duct preferably under the effect of gravity.

[0036] This makes it possible to reduce the energy consumption of the plant still further. Alternatively, or in combination with a gravity feed, a forced-drive device may be provided to drive the ice crystals toward the precooling system.

[0037] According to one embodiment of the plant, the precooling system comprises a wetting device wetting the ice crystals supplied to the precooling system, the wetting device comprising at least one water spray nozzle, a water collecting tray and a supply circuit supplying said at least one spray nozzle and in fluidic communication with the collecting tray.

[0038] A circulation loop is thus formed between the water collecting tray and the wetting of the ice crystals. The wetting device improves the exchange of heat between the ice crystals and the water supplied to the ice slurry generator.

[0039] According to one embodiment of the plant, the ice slurry generator comprises: - a reservoir to receive water from the supply system, - a refrigerant circuit extending at least partially in the vicinity of a wall of the reservoir and configured to at least partially freeze water present in the reservoir in contact with said wall, - a scraping device positioned inside the reservoir and configured to scrape off the ice crystals generated by the freezing of the water in contact with said wall. ?5 [0040] According to one embodiment of the plant, the ice slurry generator is configured to generate an ice slurry containing ice crystals of a size of 100 pm or smaller.

[0041] It has been observed that this size of ice crystals makes it possible to obtain purified water the salt concentration of which is at least 20 times lower. Thus, it is possible to obtain purified water with a salt concentration of 1.75 g/ or lower from seawater with a salt concentration of 35 g/l. Brief description of the drawings

[0042] The attached drawings illustrate the invention:

[0043] [Fig. 1] depicts a schematic view of one embodiment of a combined plant for the generation of heat energy and the desalination of water.

[0044] [Fig. 2] depicts an internal view of an ice slurry generator of the combined plant. Description of embodiment(s)

[0045] What is proposed is a combined plant for the generation of heat energy and the desalination of water. One embodiment of this combined plant is depicted in figure 1 and described hereinafter.

[0046] The combined plant 10 comprises a water supply system 12 supplying impure water, i.e. water containing a salt content above a predetermined threshold. The salt content of the impure water is, for example, comprised between 1 and 40 g/l. The water supplied to the combined plant 10 is, for example, seawater or brackish water. Seawater is defined by a salt concentration above 10 g/l. More generally, seawater has a mean salt concentration of around 35 g/l. Brackish water, also referred to as fresh water, is defined by a salt concentration comprised between 1 and 10 g/I.

[0047] The supply system 12 comprises a supply pipe 14 in fluidic communication with a water source 16. The supply system 12 comprises a feed pump 18 positioned in the supply pipe 14 to force water to circulate along the supply pipe 14. Alternatively, the seawater or brackish water is made to circulate by any means other than the forcing pump 18 or in addition to same.

[0048] The water source 16 may be a natural marine environment such as an ocean, a sea or else a river or else an anthropized marine environment. In that case, the seawater or brackish water is drawn directly from the marine environment. Alternatively, the water source 16 may be a water storage reservoir.

[0049] The combined plant 10 also comprises an ice slurry generator 20 in fluidic communication with the supply pipe 14. The ice slurry generator 20 is configured to generate an ice slurry from the water from the supply system 12. Thus, the ice slurry generator 20 is supplied with seawater or brackish water by the supply system, particularly via the feed pump 18.

[0050] The ice slurry is a fluid containing ice crystals of which the salt concentration is low and a residual liquid of which the salt concentration is high. The ice slurry generator 20 is configured to produce ice crystals of a size of 1 mm or smaller. What is meant by the "size of the ice crystals" is the longest dimension between two points on the periphery of an ice crystal. In other words, the "size" means the maximum transverse dimension. The ice crystals are preferably produced in such a way as to have a size of 500 pm or smaller, and more preferably still, of 100 pm or smaller.

[0051] The ice slurry generator 20 is preferably of the scraper type as depicted in figure 2. In that case, the slurry generator 20 comprises a reservoir 21 to accept the water from the supply system 12 and a refrigerant circuit or heat-transfer fluid circuit extending at least partially close to a wall 23 of the reservoir. The refrigerant circuit is configured to at least partially freeze water present in the reservoir in contact with said wall 23. Thus, the refrigerant cools the wall 23 of the reservoir 21 such that the water present or circulating in the reservoir 21 freezes superficially on contact with this wall 23. As a preference, the reservoir is a drum of circular cross section the external wall of which is in contact with the refrigerant and the internal wall of which is in contact with water from the supply system 12.

[0052] The ice slurry generator 20 also comprises a scraper device 27 positioned inside the reservoir and configured to scrape off the ice crystals generated by the freezing of the water in contact with said wall 23. The frequency at which the ice crystals are scraped off notably makes it possible to vary the size of the ice crystals. In the case of a reservoir 21 of circular cross section, the scraper device 27 comprises at least one scraping head 29 in contact with the wall 23 and rotated inside the reservoir 21.

[0053] At the end of scraping, an ice slurry is formed and is made up of ice crystals and of a residual liquid that has not given rise to ice crystals. The ice slurry formed is approximately at a temperature of -2 to -30 C. The ice slurry contains approximately 30% ice crystals for approximately 70% residual liquid.

[0054] The combined plant 10 further comprises a storage tank 22 for the ice slurry generated by the ice slurry generator 20. The storage tank 22 is in fluidic communication with an outlet of the ice slurry generator 20. The storage tank 22 is configured to regulate the supply of ice slurry to a separation system 24. In other words, the storage tank 22 is positioned between an outlet of the ice slurry generator 20 and an inlet 25 of the separation system 24.

[0055] The storage tank 22 is preferably thermally insulated and/or refrigerated so as to prevent the ice crystals from melting during storage, notably so as to keep the ice slurry at a temperature of0°C or below, preferably at -1°C.

[0056] The combined plant 10 may further comprise a bypass device having one inlet connected to the ice slurry generator 20, a first outlet connected to the storage tank 22 and a second outlet connected to the inlet 25 of the separation system 24. The bypass device is configured to allow the ice slurry to circulate either to the storage tank 22 or to the separation system 24 without passing via the storage tank 22. The bypass device thus permits a mode of operation in which the ice slurry does not circulate through the storage tank 22.

[0057] The separation system 24 is configured to separate the ice crystals and the residual liquid which are present in the ice slurry. The ice crystals are directed toward a first outlet 26 of the separation system 24 and the residual liquid is directed toward a second outlet 28 of the separation system 24. The residual liquid at the outlet of the separation system 24 is at a temperature of around -2 to -3 0 C. ?0 [0058] The separation system 24 is, for example, a centrifugal separation system. In other words, the separation system 24 is configured to rotate the ice slurry in such a way as to separate the ice crystals from the residual liquid on account of their difference in density. Alternatively, the ice crystals may be separated from the residual liquid in full or in part by settling. Because the ice crystals are more lightweight than the residual liquid, the ice slurry tends to form an upper phase containing the ice crystals and a lower phase containing the residual liquid.

[0059] The separation system 24 may involve one or more of the following methods: draining, spinning, centrifuging, BOchner funnel vacuum filtration, compression through a screen under a pressure of several tens of bar, Archimedean pressure filtration, etc. When the separation system employs at least two, identical or different, separation methods in succession, the final level of salinity of the desalinated water is lower than that observed after implementation of a single desalination method. Dual centrifuging makes it possible to achieve a salinity level of less than 3 PSU whereas vacuum filtration followed by centrifuging or Archimedean pressure filtration followed by centrifuging makes it possible to achieve a salinity level of less than 1 PSU.

[0060] The second outlet 28 of the separation system 24 is in fluidic communication with the water source 16 by means of a discharge pipe 30. Thus, the residual liquid can be reinjected into the water source 16. When the water source is a marine environment, the residual liquid is thus reinjected directly into this marine environment. A pump for driving the residual liquid 32 may be positioned in the discharge pipe 32 to drive the residual liquid.

[0061] The combined plant 10 further comprises a heat energy exchange system 36 exchanging heat energy with a receiver 38. This receiver 38 may be a refrigeration plant such as an air conditioning plant or a plant for the conservation of food or equipment. This exchange system 36 is in fluidic communication with the second outlet 28 of the separation system 24 via the discharge pipe 30. In particular, the exchange system 36 comprises at least a first exchanger 34 configured to exchange heat between the residual liquid and the receiver 38. In the embodiment of figure 1, the exchange system 36 comprises two first exchangers 34 to collect heat energy from the residual liquid. The heat exchanger 34 is downstream of the separation system, which is itself downstream of the precooling system.

[0062] The exchange system 36 is preferably configured to regulate the amount of heat energy exchanged with said at least one receiver 38 according to a target temperature for the residual fluid downstream of the first exchangers 34. This target temperature of the residual fluid is preferably determined as being equal to the temperature of the water in the water source 16. Thus, the impact on the water source 16 is reduced, which is particularly important when the water source 16 is a natural environment.

[0063] The plant preferably comprises a temperature sensor sensing the temperature of the residual liquid and positioned downstream of the first exchangers 34.

[0064] This regulation is preferably performed by a controller 40 configured to control one or more of the pumps of the combined plant 10. The controller 40 is also connected to the collection of sensors of the combined plant 10 so as to receive information. In particular, regulating the speed at which the residual level is driven along the discharge pipe 30 makes it possible to regulate the quantity of heat energy exchanged with the receiver 38 and therefore the temperature of the residual liquid downstream of the first exchangers 34.

[0065] The controller 40 is moreover configured to control all or part of the combined plant 10. The controller 40 is thus connected by wire or wirelessly to all or some of the components of the combined plant 10 in order to exchange information or instructions.

[0066] The first outlet 26 of the separation system 24 is in fluidic communication with a precooling system 42 precooling the water supplied to the ice slurry generator 20. In other words, the supply pipe 14 runs between the water source 16 and the ice slurry generator 20 inside the precooling system 42. Inside this precooling system 42, the water circulating inside the supply pipe 14 is precooled by the ice crystals from the separation system 24. This precooling makes it possible to lower the temperature of the water coming from the water source before it is introduced into the ice slurry generator 20. Therefore a lower amount of heat energy is needed thereafter inside the ice slurry generator 20 in order to lower the temperature of the water to its freezing point. ?0 [0067] The precooling system 42 makes it possible for example to lower the temperature of the water from the water source 16 down to a temperature of around 0°C.

[0068] The overall consumption of the combined plant 10 is thus reduced because the heat energy used for precooling the water comes from the ice generated from the ice slurry. In addition, this precooling has the second effect of raising the temperature of the ice crystals and therefore of beginning their melting process.

[0069] The separation system 24 is positioned above the precooling system 42 and configured so that the separated ice crystals are fed to the precooling system. In particular, the first outlet 26 of the separation system 24 is in fluidic communication with a precooling pipe along which the ice crystals circulate. This precooling pipe may be in the form of a chamber 43 into which the ice crystals are introduced. As a preference, the ice crystals are supplied by gravity. Alternatively or in combination with gravity feed, a forced-drive device may be provided for driving the ice crystals toward the precooling system 42.

[0070] In order to improve the exchange of heat between the ice crystals and the fluid of the supply pipe 14 on the one hand and the fluid of the exchange pipe 64 on the other hand, the precooling system 42 comprises a wetting device 44 wetting the ice crystals supplied to the precooling system 42. The wetting device 44 comprises, in the bottom part of the precooling system, a collecting tray 48 collecting water from the melting of the ice crystals. The wetting device 44 also comprises at least one spray nozzle 46 spraying water onto the supply pipe 14. These spray nozzles 46 are supplied with water by a supply circuit 50 in fluidic communication with the collecting tray 48 and the spray nozzles 46. A wetting pump 56 is positioned in the supply circuit 44 to cause the water to circulate from the collecting tray 48 to the spray nozzles 46.

[0071] That portion of the supply pipe 14 that is positioned inside the precooling pipe may be formed of a heat exchanger, for example of the plate type or of the finned tube type.

[0072] The wetting device 44 is at least partially positioned inside the precooling pipe or chamber 43. In particular, the spray nozzles 46 and the collecting tray 48 are positioned inside the precooling pipe or chamber 43. ?0 [0073] In order to distribute the purified water, the precooling pipe is in fluidic communication with a distribution pipe 52 connected to a purified water distribution plant 54. The distribution pipe 52 is thus coupled to an outlet of the precooling system. In particular, the distribution pipe 52 is in fluidic communication with the collecting tray 48 so as to collect the desalinated water obtained by the melting of the ice crystals at an outlet 51 of the precooling system 42. Specifically, the precooling or exchange of heat between the ice crystals and the water from the water source 16 causes a process of the melting of the ice crystals to begin. The fluid at the outlet 51 of the precooling system 42 is thus desalinated water obtained by the melting of the ice crystals.

[0074] The heat energy exchange system 36 further comprises at least a second exchanger 58 positioned in the distribution pipe 52. Said at least one second exchanger 58 is configured to exchange heat between desalinated water and the receiver 38. This second heat exchanger 58 is downstream of the precooling system. Said at least one second exchanger 58 is positioned between the distribution plant 54 and the precooling system 42. A distribution pump 60 positioned in the distribution pipe 52 is able to cause the desalinated water to circulate from the precooling system 42 toward the distribution plant 54.

[0075] The exchange system 36 is preferably configured to regulate the quantity of heat energy exchanged with said at least one receiver 38 according to a target temperature for the desalinated or purified water downstream of said at least one second exchanger 58. This target temperature for the desalinated water is determined by the distribution plant 54 according to the demand and the application.

[0076] The plant preferably comprises a desalinated-water temperature sensor positioned downstream of said at least second exchanger 58.

[0077] This regulation is preferably performed by the controller 40 configured to control notably the distribution pump 60. The controller 40 is also connected to the desalinated-water temperature sensor and preferably configured to communicate information with the distribution plant 54. In particular, regulating the speed at which desalinated water is driven along the distribution pipe 52 makes it possible to regulate the amount of heat energy exchanged with the receiver 38 and therefore the temperature of the desalinated water downstream of the second exchanger or exchangers 58.

[0078] The combined plant 10 may further comprise an additional exchange circuit 62 to improve the melting of the ice crystals. This additional exchange circuit 62 comprises an exchange pipe 64 of which a portion of pipe is positioned inside the precooling pipe of the precooling system 42. This portion of pipe corresponds to a heat exchanger which may be of the plate type. A heat-transfer fluid is placed inside the exchange pipe 64 so as to allow an exchange of heat between this heat-transfer fluid and the ice crystals.

[0079] The portion of pipe of the exchange pipe 64 is preferably positioned inside the precooling system 42 downstream of the portion of pipe of the supply pipe 14 in relation to the direction of circulation of the ice crystals. In this way, the ice crystals exchange heat with the water from the water source 16 before exchanging heat with the heat-transfer fluid of the exchange pipe. This makes it possible to improve the precooling of the water supplied to the ice slurry generator 20.

[0080] The additional exchange circuit 62 is connected to the receiver 38. More particularly, the exchange pipe 64 is connected at these two ends to the receiver 38. The exchange pipe 64 thus forms a loop positioned partly inside the precooling system 42 and the two ends of which are connected to the receiver 38. An exchange pump 68 is positioned in the exchange pipe 64 to circulate the heat transfer fluid between the precooling system 42 and the receiver 38.

[0081] The first exchanger 34 and second exchanger 58 are preferably plate type heat exchangers. The receiver 38 may comprise one or more receiver plants so that the first 34 and second 58 exchangers and the additional exchange circuit 62 can be connected to the one same receiving plant or to different receiving plants. The receiver 38 may comprise a disconnect bottle (also known as a mixing bottle) connected to one or more of the first 34 and second 58 exchangers and the additional exchange circuit 62 in order that this disconnect bottle can collect the heat exchanged with one or more of these first 34 and second 58 exchangers and the precooling system 42. This disconnect bottle may be in the form of a liquid reservoir having a plurality of hydraulic connections so that it can be connected, on the one hand, to one or more of the first 34 and second 58 exchangers and the precooling system 42 and, on the other hand, to one or more plants having a demand for cold.

[0082] The combined plant 10 comprises an electrical energy supply device 68 configured notably to supply electrical energy to all or some of the components of the combined plant 10. Thus, the electrical energy supply device 68 is configured to supply electrical energy to one or more of the elements that are the feed pump 18, wetting pump 56, distribution pump 60 and exchange pump 68 as well as the precooling system 42, the ice slurry generator 20, the separation system 24 and the controller 40.

[0083] As a preference, the electrical energy supply device 68 is configured to generate electrical energy from a solar energy source. Thus, the electrical energy supply device 68 preferably comprises one or more photovoltaic panels. The combined plant 10 is thus independent of any external electrical network. The electrical energy supply device 68 also preferably comprises one or more electrical accumulator batteries for storing electrical energy. As an alternative or in combination, the electrical energy supply device 68 may comprise a combustion engine and an alternator for generating electrical energy from the burning of a fuel.

[0084] Furthermore, a heat recovery system may be positioned at the condenser of the ice slurry generator 20 to transmit this heat energy to any plant having for example a demand for hot water.

Claims

Claims

[Claim 1] A combined plant (10) for the generation of heat energy and the desalination of water, the plant comprising: - a water supply system (12); - an ice slurry generator (20) in fluidic communication with the water supply system (12) and configured to generate an ice slurry from water from the water supply system (12), the slurry containing ice crystals and a residual liquid, - a separation system (24) in fluidic communication with the ice slurry generator (20) and configured to separate the ice crystals from the residual liquid toward a first outlet (26) and a second outlet (28) respectively, - a precooling system (42) precooling the water supplied to the ice slurry generator (20), the precooling system (42) comprising a precooling duct in fluidic communication with the first outlet (26) of the separation system (24) so as to allow precooling of the water supplied to the generator using the ice crystals (20), - desalinated water being obtained from the melting of the ice crystals.
[Claim 2] The combined plant (10) as claimed in claim 1, characterized in that it comprises a heat energy exchange system (36) exchanging heat energy with at least one receiver (38), the exchange system (36) comprising at least one heat exchanger (34, 58) in fluidic communication with at least one from among the precooling duct and the second outlet (28) of the separation system (24) so as to exchange heat energy coming respectively from the ice crystals or from the residual fluid with said at least one receiver (38), the heat exchanger being downstream of the precooling system.
[Claim 3] The combined plant (10) as claimed in claim 1 or 2, characterized in that the supply system (12) comprises a feed pump (18) intended to be in fluidic communication with a water source (16) so as to supply the ice slurry generator (20) with water.
[Claim 4] The combined plant (10) as claimed in any one of the preceding claims, characterized in that the second outlet (28) of the separation system is in fluidic communication with said water source (16) to allow the residual fluid to be reintroduced into the water source (16).
[Claim 5] The combined plant (10) as claimed in any one of the preceding claims, characterized in that it comprises a heat energy exchange system (36) exchanging heat energy with at least one receiver (38), the exchange system (36) comprising at least one heat exchanger (34) in fluidic communication with the second outlet (28) of the separation system (24) so as to exchange heat energy from the residual fluid with said at least one receiver (38), the exchange system (36) being configured to regulate the quantity of heat energy exchanged with said at least one receiver (38) according to a target temperature of the residual fluid downstream of said at least one heat exchanger(34).
[Claim 6] The combined plant (10) as claimed in any one of the claims, characterized in that it comprises a heat energy exchange system (36) exchanging heat energy with at least one receiver (38), the exchange system (36) comprising at least one heat exchanger (58) in fluidic communication with the precooling duct so as to exchange heat energy from the desalinated water obtained by the melting of the ice crystals with said at least one receiver (38), the exchange system (36) being configured to regulate the quantity of heat energy exchanged with said at least one receiver (38) according to a target temperature of the desalinated water downstream of said at least one heat exchanger(58).
[Claim 7] The combined plant (10) as claimed in any one of the preceding claims, further comprising an ice slurry storage tank (22) positioned between the ice slurry generator (20) and the separation system (24), the storage tank (22) being configured to regulate the supply of ice slurry to the separation system (24).
[Claim 8] The combined plant (10) as claimed in any one of the preceding claims, characterized in that the separation system (24) is a centrifugal separation system.
[Claim 9] The combined plant (10) as claimed in any one of the preceding claims, characterized in that the separation system (24) comprises a first and a second separation system, the first separation system being able to be selected from among one of the systems that are a first centrifugal system or a

BOchner funnel vacuum filtration system or an Archimedean pressure filtration system, this first separation system supplying in fluidic communication the second centrifugal separation system.
[Claim 10] The combined plant (10) as claimed in any one of the preceding claims, characterized in that the separation system (24) is positioned above the precooling system (42) and configured so that the separated ice crystals are fed to the precooling duct preferably under the effect of gravity.
[Claim 11] The combined plant (10) as claimed in any one of the preceding claims, characterized in that the precooling system (42) comprises a wetting device (44) wetting the ice crystals supplied to the precooling system (42), the wetting device (44) comprising at least one water spray nozzle (46), a water collecting tray (48) and a supply circuit (50) supplying said at least one spray nozzle (46) and in fluidic communication with the collecting tray (48).
[Claim 12] The combined plant (10) as claimed in any one of the preceding claims, characterized in that the ice slurry generator (20) comprises: - a reservoir (21) to receive water from the supply system (12), - a refrigerant circuit extending at least partially in the vicinity of a wall (23) of the reservoir (21) and configured to at least partially freeze water present in the reservoir (21) in contact with said wall (23), - a scraping device (27) positioned inside the reservoir (21) and configured to scrape off the ice crystals generated by the freezing of the water in contact with said wall (23).
[Claim 13] The combined plant (10) as claimed in any one of the preceding claims, characterized in that the ice slurry generator (20) is configured to generate an ice slurry containing ice crystals of a size of 100 pm or smaller.