US20090301128A1

US20090301128A1 - Absorber and absorber-evaporator

Info

Publication number: US20090301128A1
Application number: US12/480,638
Authority: US
Inventors: Marcelo IZQUIERDO MILLÁN; Emilio MARTÍN LÁZARO; María Esther PALACIOS LORENZO
Original assignee: Consejo Superior de Investigaciones Cientificas CSIC; Universidad Politecnica de Madrid
Current assignee: Consejo Superior de Investigaciones Cientificas CSIC; Universidad Politecnica de Madrid
Priority date: 2008-06-09
Filing date: 2009-06-08
Publication date: 2009-12-10
Also published as: JP5244230B2; JP2011516813A; WO2010000571A2; ES2381693T3; BRPI0902173A2; EP2133636B1; WO2010000571A3; EP2133636A1; BRPI0902173A8; AR073646A1; BRPI0902173B1; ATE543058T1; CA2668585A1

Abstract

Absorbers for a lithium bromide absorption machine are described. These systems may include a storage tank; a plurality of sprinklers, situated inside the storage tank, and adapted to receive a hot and concentrated lithium bromide solution, and to project the hot and concentrated solution inside the storage tank where the hot and concentrated solution is diluted to produced a diluted solution; a feed pump adapted to export the diluted solution from the absorber; a heat exchanger, positioned outside the storage tank and configured to cool the diluted solution; and a recirculation pump, configured to cause the diluted solution to be communicated from the storage tank to the heat exchanger, and to be returned from the heat exchanger to the plurality of sprinklers in a continuous recirculation process.

Description

The present application claims priority under 35 U.S.C. §119 to Spanish Patent Application No. 200801738, filed on Jun. 9, 2008, Spanish Patent Application No. 200803461, filed on Dec. 5, 2008, and Spanish Patent Application No. 200900691, filed on Mar. 12, 2009, the entirety of which are incorporated by reference herein.

BACKGROUND

Refrigeration and air-conditioning technology often use cooling machines that work with refrigerants (e.g., CFCs, HCFCs and HFCs) which are ozone-destructive (CFCs and HCFCs) and generate a much greater greenhouse effect than that of CO₂. Since in most cases, these machines use electricity, their functioning also generates carbon dioxide. As an alternative to such machines, machines based may be created which instead function on the thermodynamic principles of the absorption of a vapour by a liquid, in order to achieve the cooling of another liquid. The absorption cycles are based on the physical capacity of certain substances, such as water and certain salts, e.g., Lithium Bromide, to absorb, in liquid phase, the vapours of other substances such as Ammonia and water.

SUMMARY

Some example embodiments of the present invention may provide an absorber for a lithium bromide absorption machine, which may include a storage tank; a plurality of sprinklers, situated inside the storage tank, and adapted to receive a hot and concentrated lithium bromide solution, and to project the hot and concentrated solution inside the storage tank where the hot and concentrated solution is diluted to produced a diluted solution; a feed pump adapted to export the diluted solution from the absorber; a heat exchanger, positioned outside the storage tank and configured to cool the diluted solution; and a recirculation pump, configured to cause the diluted solution to be communicated from the storage tank to the heat exchanger, and to be returned from the heat exchanger to the plurality of sprinklers in a continuous recirculation process.
In some example embodiments, the heat exchanger may be a solution-air heat exchanger. In other example embodiments, the heat exchanger may be a solution-water heat exchanger.
In some example embodiments each of the sprinklers in the plurality of sprinklers may include a nozzle with an oval shape, adapted to spray the solution in the form of a flat sheet with an essentially triangular fan-type shape. And in example embodiments the nozzles may be arranged in such a way that the flat sheets are projected in parallel.
Some example embodiments may provide an apparatus, including an absorber, configured to operate as a single effect lithium bromide absorption machine, where the apparatus further includes a heat generator, including a heating chamber adapted to heat a lithium bromide-water solution; a heat recuperator situated between the heat generator and the absorber, configured to transfer heat from the hot and concentration solution that comes out of the generator to a diluted solution that comes from the absorber preheating the diluted solution, before the diluted solution is supplied to the heat generator; a pressure reduction valve situated between the heat recuperator and the absorber; a condenser connected to the heat generator, the condersor configured to condense water vapour produced in the heat generator; an evaporator connected to the absorber, the evaporator configured to introduce a second water vapour into the absorber; and an expansion valve which connects the condenser to the evaporator.
Other example embodiments may provide an apparatus, including an absorber, configured to operate as a double effect lithium bromide absorption machine, the apparatus further including a high pressure generator, configured to heat a lithium bromide-water solution; a low pressure generator, connected to the high pressure generator, configured to heat the lithium bromide-water solution; a high pressure recuperator in communication with the high pressure generator, adapted to send the hot and concentrated solution from the high pressure generator to the absorber; a low pressure recuperator in communication with the low pressure generator, adapted to send the hot and concentrated solution from the low pressure generator to the absorber; a first pressure reduction valve in communication with the high pressure generator; a second pressure reduction valve in communication with the low pressure generator; a solution distribution valve, situated between the feed pump, the low pressure recuperator, and the high pressure recuperator; a condenser connected to the high pressure generator which condenses water vapour produced in the high pressure generator, a sub-cooler adjacent to the condenser and connected to the low pressure generator, an evaporator connected to the absorber and adapted to introduce second water vapour into the absorber; a high pressure expansion valve, situated between the evaporator and the condenser, and between the evaporator and the sub-cooler; and a low pressure expansion valve, situated between the evaporator and the condenser, and between the evaporator and the sub-cooler.
In some examples such an apparatus may be further configured to operate as a combined use lithium bromide absorption machine, and may further include a second generator; a second recuperator; a connection valve between the second generator and the condenser; a return valve, situated between the second recuperator and a branch that runs from the solution distribution valve to the feed pump; a circulation valve, which connects the low pressure generator to the sub-cooler; and a second circulation valve, which connects the low pressure generator to the condenser. And in some examples the second generator is configured to use a renewable source of energy.
Other example embodiments may provide an absorber-evaporator assembly, which may include a storage tank; a plurality of sprinklers, situated inside the storage tank, and adapted to receive a hot and concentrated lithium bromide solution, and to project the hot and concentrated solution inside the storage tank where the hot and concentrated solution is diluted to produced a diluted solution; a feed pump adapted to export the diluted solution from the absorber; a heat exchanger, positioned outside the storage tank and configured to cool the diluted solution; a recirculation pump, configured to cause the diluted solution to be communicated from the storage tank to the heat exchanger, and to be returned from the heat exchanger to the plurality of sprinklers in a continuous recirculation process; an evaporator in the storage tank; and an isolating vertical separating wall fitted in the storage tank, the wall defining an evaporation chamber including the evaporator and an absorption chamber, the evaporation chamber and the absorption chamber in communication at an upper part.
In some examples, the heat exchanger may be a solution-air heat exchanger. And in other examples, the heat exchanger may be a solution-water heat exchanger.
In some examples, each of the sprinklers in the row of sprinklers may include a nozzle with an oval shape, adapted to spray the solution in the form of a flat sheet with an essentially triangular fan-type configuration. And in some examples, the nozzles may be arranged in such a way that the flat sheets are projected in parallel.
In some examples, the absorption chamber may include a collector adapted to receive the hot and concentrated solution, and to receive a recirculation line; and the plurality of sprinklers may be mounted to the collector.
Other examples may provide an apparatus configured to operate as a single effect lithium bromide absorption machine, including an absorber-evaporator assembly, and further including a heat generator with a heating chamber adapted to heat the lithium bromide-water solution, a heat recuperator situated between the heat generator and the absorber-evaporator assembly, configured to transfer heat from a hot and concentrated solution that comes out of the generator to a diluted solution that comes from the absorber-evaporator assembly, preheating the diluted solution, before feeding the diluted solution to the heat generator; a pressure reduction valve situated between the heat recuperator and the absorber-evaporator assembly; a condenser connected to the heat generator configured to condense water vapour produced in the heat generator, and an expansion valve which connects the condenser to the absorber-evaporator assembly.
Other examples may provide an apparatus configured to operate as a double effect lithium bromide absorption machine, including an absorber-evaporator assembly, the apparatus further including a high pressure generator configured to heat the lithium bromide-water solution; a low pressure generator, connected to the high pressure generator, configured to heat the lithium bromide-water solution, a high pressure recuperator in communication with the high pressure generator, adapted to send the hot and concentrated solution from the high pressure generator to the absorber-evaporator assembly; a low pressure recuperator in communication with the low pressure generator, adapted to send the hot and concentrated solution from the low pressure generator to the absorber-evaporator assembly; a first pressure reduction valve in communication with the high pressure generator; a second pressure reduction valve in communication with the low pressure generator; a solution distribution valve situated between the feed pump, the high pressure recuperator, and the low pressure recuperator; a condenser connected to the high pressure generator which condenses water vapour produced in the high pressure generator; a sub-cooler adjacent to the condenser and connected to the low pressure generator; a high pressure expansion valve, situated between the absorber-evaporator assembly and the condenser, and between the absorber-evaporator assembly and the sub-cooler; and a low pressure expansion valve, situated between the absorber-evaporator assembly and the condenser, and between the absorber-evaporator assembly and the sub-cooler.
In some examples such an apparatus may be further configured to operate as a combined use lithium bromide absorption machine and may further include a second generator; a second recuperator; a connection valve between the second generator the condenser; a return valve, situated between the second recuperator and a branch that runs from the solution distribution valve to the feed pump; a circulation valve, which connects the low pressure generator to the sub-cooler; and a second circulation, which connects the low pressure generator to the condenser. And in some examples, the second generator may be configured to use a renewable source of energy.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be more readily understood from a detailed description of the example embodiments taken in conjunction with the following figures:

FIG. 1 shows an outline of a single effect absorption machine according to an example embodiment of the present invention.

FIG. 2 shows an elevated section view of a nozzle connected to a sprinkler according to an example embodiment of the present invention.

FIG. 3 shows a plan view of a nozzle according to an example embodiment of the present invention.

FIG. 4 shows a schematic view of a sprinkler with a nozzle projecting a flat sheet, with a triangular fan-type shape, according to an example embodiment of the present invention.

FIG. 5 shows a heat generator with exchanger according to an example embodiment of the present invention

FIG. 6 shows a heat generator with burner according to an example embodiment of the present invention.

FIG. 7 shows an outline of a double effect absorption machine according to an example embodiment of the present invention.

FIG. 8 shows an outline of an absorption machine according to an example embodiment of the present invention.

FIG. 9 shows an outline of a single effect absorption machine according to an example embodiment of the present invention.

FIG. 10 shows an outline of a double effect absorption machine according to an example embodiment of the present invention.

FIG. 11 shows an elevated section view of an absorber-evaporator assembly according to an example embodiment of the present invention.

FIG. 12 shows a side section view of an absorber-evaporator assembly according to an example embodiment of the present invention.

FIG. 13 shows an elevated section view of an absorber-evaporator assembly according to an example embodiment of the present invention.

FIG. 14 shows a side section view of an absorber-evaporator assembly according to an example embodiment of the present invention.

DETAILED DESCRIPTION

Example embodiments of the present invention provide for absorption machines which may be suitable for use in air-conditioned buildings, private dwellings, business premises, cold stores, greenhouses, industrial buildings, etc., as well as in vehicles including boats, city and intercity buses, trucks, truck cabins, etc. In addition, such absorption machines may be condensed by water or condensed by air, etc.
In such absorption machines a process may occur whereby a refrigerant, water, ammonia, etc., is evaporated in an evaporator using heat from the change of state of a fluid that circulates inside the tube bundle of an exchanger. The vapours produced may be absorbed by an absorbent, water or lithium bromide solution, etc., in a dissolving process in which their temperature increases, requiring external cooling so that the solution is kept at the right temperature conditions and the pressure does not increase in the chamber where the absorption occurs. Some examples may include external cooling circuits in which, e.g., water cooling towers are used. Water cooled in such towers may be made to circulate inside the tube bundle of another exchanger which may be situated inside the absorber chamber and on which the absorbent is sprinkled to facilitate the absorption process. The mass of absorbent containing the refrigerant may be transported, by means of pumps, to another heat exchanger whose function is to separate the refrigerant from the absorbent, by distillation of the former. This heat exchanger may be referred to as the generator. Through its tube bundle the hot fluid is made to circulate, normally water or water vapour, which constitutes the main source of energy for the absorption cycle to function, and which can also arrive as the effluent from any other type of process that generates residual heat.
Example embodiments of the present invention may relate to absorption machines used in air-conditioning and/or refrigeration installations, which may function using a solution of lithium bromide-water. Some example embodiments of the present invention provide for an absorber for an absorption machine. Other example embodiments provide for an absorber-evaporator assembly. Other example embodiments provide a single effect lithium bromide absorption machine integrating the abovementioned absorber or absorber-evaporator assembly. Other example embodiments provide a double-effect lithium bromide absorption machine integrating the abovementioned absorber or absorber-evaporator assembly. And other example embodiments provide a lithium bromide absorption machine which alternates between single and double-effect functioning, integrating the abovementioned absorber or absorber-evaporator assembly.
The absorption machine which is provided by example embodiments of the present invention may be used in air-conditioning or refrigeration installations, for example systems that use the absorption of lithium bromide and water. For example, some embodiments provide for a single effect lithium bromide-water absorption machine which may, for example, include the following elements: an absorber capable of maintaining a low pressure and low evaporation temperature when the outside temperature is high, with direct cooling by outside air or by water, which carries out separate heat and mass transfer processes, a condenser cooled directly by outside air or by water from a tower or from another refrigeration circuit, an evaporator, a heat generator, and a heat recuperator.
In such example embodiments, the heat generator may include a heating chamber which may have a heat exchanger, which may be made of refractory stainless steel, when the source of heat is direct flame, in such a way that it facilitates the transfer of heat to a lithium bromide-water solution. In some examples the exchanger may be configured to use the heat produced by a field of solar captors, by a biomass boiler, by a bio-diesel boiler, by a bio-ethanol boiler, by a conventional fossil fuel boiler, or the residual heat of engine exhaust fumes, fuel batteries, fuel cells, or any thermal process that generates a sufficient temperature of residual heat.
The generator may likewise incorporate as, an alternative or complement to the exchanger, a low, medium or high-powered modulating burner controlled by a PDI regulator which may allow the temperature to be controlled at will, and which may generate heat in the heating chamber as a consequence of the combustion of a fossil fuel, preferably GLP, GN, diesel oil, Biodiesel, Biogas or others.
Additionally, in the heating chamber the generator may be fitted with a water vapour separator.
A lithium bromide solution may be introduced diluted into the generator's heating chamber, where it may absorb the heat, boiling at a temperature generally between 85° C. and 125° C., or more, which may depend on the T of the outside air, and which may produce reheated refrigerant vapour (hot and concentrated solution) and water vapour, which may then be separated in the separator. The water vapour may leave the generator and may be sent to the condenser, where it is transformed into liquid, which may then be sent through an expansion valve to the evaporator where it is once again converted into water vapour.
The heat recuperator may be a plate exchanger with copper welds, and may be configured to transfer the heat from the hot and concentrated solution that comes out of the generator to the diluted and cold solution that comes from the absorber, preheating it, before it is supplied to the generator.
The hot and concentrated solution from the generator may travel through the recuperator and its pressure may be reduced in a reduction valve which may be situated between the recuperator and the absorber, so that solution may enter the absorber at a lower pressure.
In some example embodiments the absorber may contain: a storage tank, a row of sprinklers situated inside the storage tank through which the hot and concentrated solution passes for sprinkling inside the tank where upon contact with the water vapour from the evaporator it becomes diluted, a heat exchanger, outside the storage tank and preferably finned, which cools the diluted solution, a recirculation pump which sucks in the diluted solution from the storage tank and propels it towards the heat exchanger from which the cooled diluted solution is expelled returning to the row of sprinklers in a continuous recirculation process encouraging the increased transfer of mass and heat, and a generator feed pump that sucks in the diluted solution from the absorber and propels it towards the generator, through the recuperator, where the solution becomes concentrated again.
The absorber may transmit the absorption heat from the solution in the absorber directly to the atmospheric air, through the heat exchanger. In this way, example embodiments of the present invention are fundamentally different than machines which may first transfer the absorption heat from the solution to a water circuit and then from the water to the outside air propelled by the fan. Accordingly, in example embodiments of the present invention, the difference in temperature between the solution and the outside air may be increased in respect of the difference in temperatures that re-cooling requires, and, therefore, heat transfer may be better, the area of exchange may be lower, an exchanger may be conserved, and the absorption temperature may be made to approach the temperature of the outside air as much as possible.
In some example embodiments the absorber may be configured to sprinkle the solution. Sprinkling may facilitate the transfer of mass, and since the absorption process is adiabatic, the heat transfer may occur in an independent and external exchanger, which by working with a high efficiency also reduces the needed exchange area.
Absorption may be obtained by sprinkling the solution in the form of flat parallel sheets, with an essentially fan-type triangular shape, which may facilitate very efficient transfer of mass.
In some example embodiments, the sprinklers may have oval-shaped nozzles which may be configured to allow the sprinkling of the solution in a flat sheet with the abovementioned fan shape, said flat sheet having a large surface, which may remain in contact with the water vapour from the evaporator and present in the absorber chamber encouraging the absorption.
Such example embodiments may provide for a low volume absorbers and highly efficient solution-air heat exchangers with a low area. Accordingly, such example embodiments may allow for the total volume of the absorber-exchanger to be small and, therefore, may allow for the volume of the machine itself to be small. In summary, some of the advantages offered by example embodiments of the present invention may include absorbers with high heat and mass transfer coefficients, with a low volume/power ratio, which are easy to build, easy to access, easy to inspect and easy to maintain. Such example absorbers may be used for both single and multi-effect machines.
In some example embodiments, the evaporator may incorporate an exchanger through the inside of which may circulate water coming from the space intended for cooling, for example, a commercial premises, the inside of a car, a cold store, etc., and also may have a cold air pump that may propel the water cooled in the exchanger towards the cooling device installed in the space to be air-conditioned.
The condenser may be specifically designed for low pressure water vapour coming from the generator and may be integrated in the machine in two phases in order to save space. Given its small size and its arrangement inside the machine, the design of the condenser may help to reduce the overall size of the overall machine. The condenser may, for example, be cooled by air, in which case it may include, e.g., a heat exchanger and a fan, wherein the heat exchanger may be made of copper tubes with aluminium fins. Other condensers may be cooled using water from a tower or from another refrigeration circuit. In example embodiments, the water vapour produced in the generator, which may be at a temperature of between 80° C. and 125° C., may be condensed directly by the outside air when working with refrigeration, or by the air of the space to be cooled, for example the inside of a building, when working in heating mode.
It is noted that example absorption machines according to the present invention can use exhaust fumes or renewable heat or renewable fuel or fuel from a conventional fuel boiler to transfer its heat in the generator.
Such absorption machines may be capable of producing cold in a static or mobile fridge, capable of working on inclined planes and with sharp accelerations, e.g., in city or intercity diesel buses with spontaneous ignition, in city or intercity petrol buses with provoked ignition, in both petrol and diesel lorries and trucks, for the transport of refrigerated products, on both petrol and diesel-fuelled thermal engine craft, and in thermal engine vehicles other than those indicated in the preceding claims, which have hot exhaust fumes. Such example systems may also be configured to air-condition greenhouses, to cool refrigerated stores at temperatures above 7° C., and to air-condition premises where thermal engines are used.
In some examples, the lithium bromide-water absorption machine can be used as a system for producing additional heat. For example, in an automobile system, the lithium bromide-water absorption machine may be capable of producing heat beyond that of the exhaust fumes, e.g., during extended periods in neutral gear, by combustion of additional fuel external to the engine or internally in the combustion chamber itself, Similarly, such example systems may produce additional heat to that of exhaust fumes during extended journeys by road or rail.
Another example embodiment of the present invention may provide a multiple effect absorption machine, such as a double-effect machine, which in addition to the elements of the single effect machine may also include another generator, another recuperator and a sub-cooler.
Such a double-effect machine may include both a high pressure generator and a low pressure generator connected to the high pressure one, where the high pressure generator is associated with the heating chamber that may be fitted with a burner. Each of the high and low pressure generators may in turn be connected respectively to a high and low pressure recuperator which may send the hot and concentrated solution from the generators to the absorber via the corresponding pressure reduction valves.
The low pressure generator connected after the high pressure generator may separate the refrigerant vapour and the liquid water. The vapour may be directed to a condenser, while the liquid water may be sent to a sub-cooler adjacent to the condenser. Next, the water vapour condensed in the condenser and in the sub-cooler may be directed to high and low pressure expansion valves, respectively, where the pressure and temperature may be reduced until entry into the evaporator.
Unlike with the single effect machine, the absorber may have an additional input connected to the high pressure recuperator via one of the previously mentioned pressure reduction valves, and the feed pump to the generator may direct the diluted solution to the high and low pressure recuperators via a solution distribution valve. In example embodiments, the heat exchanger of the absorber may be a solution-air exchanger or, alternatively, may be a solution-water exchanger, where the water is cooled by the water from a tower.
In other example embodiments, both the single effect and multiple effect machines may have the absorber and evaporator integrated in an absorber-evaporator assembly. Such an absorber-evaporator assembly may have a container or storage tank with a separating isolating wall perpendicular to the base of the container which may generate two spaces or chambers that allow mixing of the gases or water vapour in the upper part, since the wall does not reach the lid or top surface of the container. The evaporator may be inside an evaporation chamber and may include a tube bundle that forms a circuit through which the refrigerating liquid circulates normally, coming from the room to be cooled, leaving the tubes that are located in the upper part of the evaporation chamber at a higher temperature than the tubes located in the lower part of the chamber or viceversa.
In such an evaporator, the water that reaches the evaporation chamber, coming from the condenser, may be made to evaporate. The water, once evaporated, may pass in the form of water vapour to the adjacent chamber or absorption chamber.
The water vapour coming from the evaporation chamber may be introduced into the absorption chamber, which may be adjacent to the evaporation chamber, and may reach a collector on which sprinklers are mounted from which the hot concentrated solution is discharged.
The described configuration may be applied in both single effect absorption machines and multiple effect absorption machines, such as double or even triple effect. Depending on the type of collector, there might be one, two or three lines of hot concentrated solution coming from two generators, as well as one, two or three inputs of water coming from a condenser.
Another example embodiment of the present invention may provide for a combined-use absorption machine, which may combine the single effect functioning mode with the double effect mode, where the functioning may alternate between the two modes depending on the needs of the installation it serves, and which may include a system of pipes and valves that makes it possible to determine the functioning mode. Such an absorption machine may likewise include the described absorber or absorber-evaporator assembly.
Such a combined use absorption machine could be configured to facilitate the use of renewable energies. For instance, in the case of using renewable energies, the single effect machine may use a renewable energy, such as solar energy or recovered residual heat, and the double effect machine may use a commercial fuel as a source of heat.
For example, FIG. 1 depicts an outline of a single effect lithium bromide absorption machine in accordance with an example embodiment of the present invention. As illustrated, the absorption machine may include a heat generator (1) which may have a heating chamber (2) adapted to heat a lithium bromide-water solution that includes a water vapour separator (not shown). The machine may also include an absorber (3), which may itself include a storage tank (4); a row of sprinklers (5), situated inside the storage tank (4) through which the hot and concentrated solution may be passed and which may then be projected inside the tank (4) for its dilution; a heat exchanger (6), outside the storage tank (4) which may cool the diluted solution; a recirculation pump (7) which may suck in the diluted solution from the storage tank (4) and propel it towards the heat exchanger (6) from which the cooled diluted solution may emerge returning to the row of sprinklers (5) in a continuous recirculation process; and a feed pump (8) which may be adapted to supply the heat generator (1), sucking in the diluted solution from the absorber (3) and sending it to the generator (1) where the solution is concentrated again,
The example machine may also include a heat recuperator (9) which may be situated between the generator (1) and the absorber (3) in which the heat may be transferred from the hot and concentrated solution that comes out of the generator (1) to the diluted and cold solution that comes from the absorber (3), preheating it, before it is supplied to the generator (1). In addition, the example machine may also include a pressure reduction valve (10) which may be situated between the heat recuperator (9) and the absorber (3); a condenser (11) which may be connected to the generator (1) and which may condense the water vapour produced in the generator (1); an evaporator (12) which may be connected to the absorber (3) and which may be adapted to introduce water vapour into the absorber (3); and an expansion valve (13) which may connect the condenser (11) to the evaporator (12).
In such example absorption machines, each one of the sprinklers of the row of sprinklers (5) may include oval-shaped nozzles (14), shown in FIGS. 2 and 3, which may be adapted to spray the solution in the form of a flat sheet (15) with an essentially triangular fan-type shape, as can be appreciated from FIG. 4, where the nozzles (14) of the sprinklers are arranged preferably in such a way that said flat sheets (15) are projected in parallel, as may be observed in FIG. 1.
In some example embodiments, the heat exchanger (6) of the absorption machine may be a solution-air exchanger, as shown in FIG. 1 with a fan (16) associated with said exchanger. In other example embodiments, however, the heat exchanger (6) may be of the solution-water type. In some example embodiments, the fan (16) of the solution-air heat exchanger (6) may be the same as the fan (16) that cools the condenser (11), as may be observed in FIG. 1.
FIGS. 5 and 6 show that the generator (1) may integrate in the heating chamber (2) a heat exchanger (23) and/or associated with the heating chamber may be a fossil fuel burner (17).
FIG. 1 shows an example application of the absorption machine to a space to be air-conditioned (18), wherein it can be appreciated that the evaporator (12) may integrate an exchanger (19) through the inside of which circulates water coming from the space to be air-conditioned (18) for cooling. In addition, a cold water pump (20) may be configured to send the water cooled in the exchanger (19) to a cooling device (21) installed in the space to be air-conditioned (18), which may be fitted with a fan (22).
FIG. 7 illustrates an example double effect lithium bromide machine that may include some of the elements appearing in FIG. 1 of the example single effect machine. Instead of a single generator, however, the example double effect machine may have a high pressure generator (1′) and a low pressure generator (1″) connected to the high pressure generator (1′), where the high pressure generator (1′) may be associated with the burner (17). At the same time, each one of the generators of high (1′) and low pressure (1″) may in turn be connected respectively to a high pressure recuperator (9′) and a low pressure recuperator (9″) which may send the hot and concentrated solution from the high and low pressure generators (1′, 1″) to the absorber (3), integrating pressure reduction valves (10′, 10″) between them and the absorber (3).
The low pressure generator (1″) may be connected to the condenser (11) and to a sub-cooler (24) adjacent to the condenser (11). From the condenser (11) and the sub-cooler (24) may come condensed water vapour which may be sent to high (13′) and low (13″) pressure expansion valves, respectively, where the pressure and temperature may be reduced until their entry into the evaporator (12).
In some example machine, an additional input to the absorber (3) may be provided, which would be connected to the low pressure recuperator (9″) via the pressure reduction valve (10″) mentioned above. In some examples, the feed pump (8) may direct the solution diluted in the absorber (3) towards the high (9′) and low pressure recuperators (9″) via a solution distribution valve (25).
FIG. 8 shows an absorption machine, according to another example embodiment of the present invention, that alternates functioning between a single effect and a double effect machine, incorporating a series of valves that allow one mode or another to be enabled. Such an example machine may includes a connection valve (37) between generator (1) and condenser (11); a return valve to the recuperator (26), which may be situated between recuperator (9) and a branch running from the solution distribution valve (25) to the feed pump (8); a circulation valve to the sub-cooler (27), which may connect the low pressure generator (1″) to the sub-cooler (24); and a circulation valve to the condenser (28) which may connect the low pressure generator (1″) to the condenser (11).
In example embodiments, two functioning mode may be distinguished for the machine—a single effect functioning mode and a double effect functioning mode. In the case of the single effect mode, the circulation of the fluid intervening in the functioning of the machine has been represented in a thick line, wherein only the pressure reduction valve (10), the return valve to the recuperator (26), the connection valve (37), and the high pressure expansion valve (13′) are opened, while the rest of the valves remain closed. In the case of the example machine functioning in double effect mode, only the return valve to the recuperator (26), the expansion valve (10) and the connection valve (37) are closed.
FIG. 9 illustrates a single effect absorption machine in accordance with another embodiment of the present invention. In the example machine depicted in FIG. 9, instead of the absorber (3), an absorber-evaporator assembly (3′) is integrated, represented in the figure in schematic form, and which includes a storage tank (4′) equipped with a vertical isolating separating wall (29) which forms two chambers (30, 33) communicating with each other by their upper part—an evaporation chamber (30) defined on one side of the vertical separating wall (29) which may include an evaporator (32), and an absorption chamber (33) defined on the other side of the vertical separating wall (29) where the concentrated solution may be diluted.
This absorber-evaporator assembly (3′) may also include a feed pump (8) adapted to extract the diluted solution, a heat exchanger (6) outside which cools the diluted solution, and a recirculation pump (7) which sucks in the diluted solution and propels it towards the heat exchanger (6) for its return to the row of sprinklers (5) in a continuous recirculation process.
FIG. 10 shows depicted an example double effect absorption machine that likewise integrates such an absorber-evaporator assembly (3′).
In FIGS. 11 and 12 the absorber-evaporator assembly can be appreciated in greater detail. In such example systems, the vertical wall (29), shown in FIG. 12 may allow the vapour to pass from the evaporation chamber (30) to the absorption chamber (33) by the upper part of the storage tank (4′), since the separating wall (29) does not reach the top.
The evaporation chamber (30) may receive at least one water supply line (38) from the condenser (11) until it reaches the evaporator (32), which may include a circuit of refrigerant liquid formed by tubes (35), where secondary hot refrigerant liquid circulates (e.g., at approximately 10° C.-18° C.) through the upper tubes (35), and secondary cooler refrigerant liquid circulates (e.g., at approximately 7° C.-15° C.) through the lower tubes (35). Such secondary refrigerant liquid may be sent to the room (18) to be cooled, to a cold store, a greenhouse, etc. When the water comes into contact with the tubes (35) of the refrigerant liquid circuit, the water which is at very low pressure (e.g., approximately 8-15 mbar) evaporates and rises inside the evaporation chamber (30) surpassing the vertical separating wall (29) and reaching the absorption chamber (33).
In the absorption chamber (33), the water vapour arriving from the evaporation chamber (30) may come into contact with the lithium bromide solution that may be projected from the sprinklers (5).
In some example embodiments, the absorption chamber (33) may include a collector (36) adapted to receive the hot and concentrated refrigerant solution coming from the recuperator (9). In such examples, it may be the collector (36) on which the abovementioned sprinklers (5) are mounted. In addition, the collector (36) may be adapted to receive a recirculation line (39).
Hence, from this solution collector (36) the bromide solution may be sprinkled via sprinklers (5). Sprinkling in the form of flat sheets (15) of lithium bromide may favour its dilution with the vapour.
Once projected the sheet of solution may fall to the bottom of the absorption chamber (33), as can be seen from FIG. 12, from where, once diluted, part of the solution may be sent to the generator (1) with the help of the feed pump (8), and another part may be directed, by means of the exchanger (6), to the solution collector (7) of the absorption chamber (13) or the container (10), once again initiating the absorption process. Again, the heat exchanger (6) may be of either the solution-air or solution-water type, or of any other practical type.
In example embodiments, the absorber assembly (3′) may be included in a double effect machine, as shown in FIG. 10. As depicted in detail in FIGS. 13 and 14, the absorber-evaporator assembly (3′) may maintain the same structure, with the inclusion of relevant input lines to the collector (36), in this case coming from the two recuperators (9′, 9″) and of relevant water input lines (38) coming from the condenser (11) and sub-cooler (24).
In the preceding specification, the present invention has been described with reference to specific example embodiments thereof. It will, however, be evident that various modifications and changes may be made thereunto without departing from the broader spirit and scope of the present invention as set forth in the claims that follow. The specification and drawings are accordingly to be regarded in an illustrative rather than restrictive sense. It is also noted that the subject matter headings used throughout the specification are intended only as an organizational aid and are not to be read as limiting the scope of the disclosure.

Claims

1. An absorber for a lithium bromide absorption machine, comprising:

a storage tank;

a plurality of sprinklers, situated inside the storage tank, and adapted to receive a hot and concentrated lithium bromide solution, and to project the hot and concentrated solution inside the storage tank where the hot and concentrated solution is diluted to produced a diluted solution;

a feed pump adapted to export the diluted solution from the absorber;

a heat exchanger, positioned outside the storage tank and configured to cool the diluted solution; and

a recirculation pump, configured to cause the diluted solution to be communicated from the storage tank to the heat exchanger, and to be returned from the heat exchanger to the plurality of sprinklers in a continuous recirculation process.

2. The absorber of claim 1, wherein the heat exchanger is a solution-air heat exchanger.

3. The absorber of claim 1, wherein the heat exchanger is a solution-water heat exchanger.

4. The absorber of claim 1, wherein each of the sprinklers in the plurality of sprinklers comprises a nozzle with an oval shape, adapted to spray the solution in the form of a flat sheet with an essentially triangular fan-type shape

5. The absorber of claim 4, wherein the nozzles are arranged in such a way that the flat sheets are projected in parallel.

6. The apparatus of claim 1 further configured to operate as a single effect lithium bromide absorption machine, the apparatus further comprising:

a heat generator, including a heating chamber adapted to heat a lithium bromide-water solution;

a heat recuperator situated between the heat generator and the absorber, configured to transfer heat from the hot and concentration solution that comes out of the generator to a diluted solution that comes from the absorber preheating the diluted solution, before the diluted solution is supplied to the heat generator;

a pressure reduction valve situated between the heat recuperator and the absorber;

a condenser connected to the heat generator, the condersor configured to condense water vapour produced in the heat generator;

an evaporator connected to the absorber, the evaporator configured to introduce a second water vapour into the absorber; and

an expansion valve which connects the condenser to the evaporator.

7. The apparatus of claim 1 further configured to operate as a double effect lithium bromide absorption machine, the apparatus further comprising:

a high pressure generator, configured to heat a lithium bromide-water solution;

a low pressure generator, connected to the high pressure generator, configured to heat the lithium bromide-water solution;

a high pressure recuperator in communication with the high pressure generator, adapted to send the hot and concentrated solution from the high pressure generator to the absorber;

a low pressure recuperator in communication with the low pressure generator, adapted to send the hot and concentrated solution from the low pressure generator to the absorber;

a first pressure reduction valve in communication with the high pressure generator;

a second pressure reduction valve in communication with the low pressure generator;

a solution distribution valve, situated between the feed pump, the low pressure recuperator, and the high pressure recuperator;

a condenser connected to the high pressure generator which condenses water vapour produced in the high pressure generator,

a sub-cooler adjacent to the condenser and connected to the low pressure generator,

an evaporator connected to the absorber and adapted to introduce second water vapour into the absorber;

a high pressure expansion valve, situated between the evaporator and the condenser, and between the evaporator and the sub-cooler; and

a low pressure expansion valve, situated between the evaporator and the condenser, and between the evaporator and the sub-cooler.

8. The apparatus of claim 7 further configured to operate as a combined use lithium bromide absorption machine, the apparatus further comprising:

a second generator;

a second recuperator;

a connection valve between the second generator and the condenser;

a return valve, situated between the second recuperator and a branch that runs from the solution distribution valve to the feed pump;

a circulation valve, which connects the low pressure generator to the sub-cooler; and

a second circulation valve, which connects the low pressure generator to the condenser.

9. The apparatus of claim 8, wherein the second generator is configured to use a renewable source of energy.

10. An absorber-evaporator assembly, comprising:

a storage tank;

a feed pump adapted to export the diluted solution from the absorber;

a heat exchanger, positioned outside the storage tank and configured to cool the diluted solution;

a recirculation pump, configured to cause the diluted solution to be communicated from the storage tank to the heat exchanger, and to be returned from the heat exchanger to the plurality of sprinklers in a continuous recirculation process;

an evaporator in the storage tank; and

an isolating vertical separating wall fitted in the storage tank, the wall defining an evaporation chamber including the evaporator and an absorption chamber, the evaporation chamber and the absorption chamber in communication at an upper part.

11. The absorber-evaporator assembly of claim 10, wherein the heat exchanger is a solution-air heat exchanger.

12. The absorber-evaporator assembly of claim 10, wherein the heat exchanger is a solution-water heat exchanger.

13. The absorber-evaporator assembly of claim 10, wherein each of the sprinklers in the row of sprinklers comprises a nozzle with an oval shape, adapted to spray the solution in the form of a flat sheet with an essentially triangular fan-type configuration.

14. The absorber-evaporator assembly of claim 13, wherein the nozzles are arranged in such a way that the flat sheets are projected in parallel.

15. The absorber-evaporator assembly of claim 11, wherein:

the absorption chamber includes a collector adapted to receive the hot and concentrated solution, and to receive a recirculation line; and

the plurality of sprinklers are mounted to the collector.

16. The apparatus of claim 10 further configured to operate as a single effect lithium bromide absorption machine, the apparatus further comprising:

a heat generator with a heating chamber adapted to heat the lithium bromide-water solution,

a heat recuperator situated between the heat generator and the absorber-evaporator assembly, configured to transfer heat from a hot and concentrated solution that comes out of the generator to a diluted solution that comes from the absorber-evaporator assembly, preheating the diluted solution, before feeding the diluted solution to the heat generator;

a pressure reduction valve situated between the heat recuperator and the absorber-evaporator assembly;

a condenser connected to the heat generator configured to condense water vapour produced in the heat generator, and

an expansion valve which connects the condenser to the absorber-evaporator assembly.

17. The apparatus of claim 10, further configured to operate as a double effect lithium bromide absorption machine, the apparatus further comprising:

a high pressure generator configured to heat the lithium bromide-water solution;

a low pressure generator, connected to the high pressure generator, configured to heat the lithium bromide-water solution,

a high pressure recuperator in communication with the high pressure generator, adapted to send the hot and concentrated solution from the high pressure generator to the absorber-evaporator assembly;

a low pressure recuperator in communication with the low pressure generator, adapted to send the hot and concentrated solution from the low pressure generator to the absorber-evaporator assembly;

a solution distribution valve situated between the feed pump, the high pressure recuperator, and the low pressure recuperator;

a condenser connected to the high pressure generator which condenses water vapour produced in the high pressure generator;

a sub-cooler adjacent to the condenser and connected to the low pressure generator;

a high pressure expansion valve, situated between the absorber-evaporator assembly and the condenser, and between the absorber-evaporator assembly and the sub-cooler; and

a low pressure expansion valve, situated between the absorber-evaporator assembly and the condenser, and between the absorber-evaporator assembly and the sub-cooler.

18. The apparatus of claim 17 further configured to operate as a combined use lithium bromide absorption machine, the apparatus further comprising:

a second generator;

a second recuperator;

a connection valve between the second generator the condenser;

a second circulation, which connects the low pressure generator to the condenser.

19. The apparatus of claim 18, wherein the second generator is configured to use a renewable source of energy.