VAPORISER/CONDENSER INSTALLATION AND ENERGY SYSTEM PROVIDED WITH SUCH AN INSTALLATION

Abstract: An installation for the vaporisation or condensation of a liquid or vapour respectively, is provided with a holder (3) for the liquid with means for supplying or removing heat, which holder (3) is provided with a capillary structure (7) which extends above and below the liquid level. An energy system provided with at least one heat accumulator (21, 22) containing at least one heat-transporting substance which can be either in the liquid phase or in the vapour phase, and containing a crystalline material which exothermally absorbs and endothermally desorbs the heat-transporting substance, which heat accumulator has means for the supply or removal of heat (17, 18; 32, 33), contains the above installation for the heat-transporting substance, which installation is connected via a closable vapour line (16, 25) to the heat accumulator.

Description: Vaporiser/condenser installation and energy svsten- provided with such an installation The invention relates to an installation for the vaporisation or condensation of a liquid or vapour respectively, provided with a holder for the liquid with means for supplying or removing heat. Installations of this type are generally known and are used in many fields, for example for heat storage systems. In these systems energy is stored in the form of heat in a solid or liquid substance (the absorber) by vaporising an absorbed substance (the sorbate) therefrom. The known vaporiser/condenser installations have a number of disadvantages. Thus, a substantial excess temperature is usually needed for the vaporisation, certainly when vaporising from a bath. Furthermore, a separate construction or heat exchanger is often needed for the vaporisation and condensation processes. As the amount of sorbate which is present in the installation changes, there is also a change in the surface available for vaporisation or condensation, and thus also in the available power. The aim of the invention is, therefore, to provide an installation of the abovementioned type which does not have these disadvantages. This is achieved in that the holder is provided with a capillary structure which extends above and below the liquid level. The capillaries in the capillary structure ensure that an appreciable part of that section of said structure which is located above the liquid level is kept wet. The energy which is required for the vaporisation of the liquid from that section of the capillary structure is thus minimal. Compared with, for example, a wet film vaporiser/ condenser, the installation according to the invention also has the advantage that separate means are not needed for dispersing the liquid to be vaporised over the surface of the installation. Finally, the capillary structure also constitutes a suitable means for condensing the vapour. The capillary structure preferably consists of one or more layers of fine-mesh gauze. A combination of coarse-mesh and fine-mesh layers of gauze can also be used. Other possibilities are sintered, flame-sprayed or grooved structures. The capillary structure, such as a gauze, can be applied to the inner wall of the holder. As an alternative, or as a supplement, the holder can be provided on the inside with support elements on which the capillary structure is applied. The liquid level in the holder varies during operation of the installation, depending on the vaporisation and condensation. If the variations do not become too great, this is no problem whatsoever since the amount of liquid absorbed in the gauze also varies over a certain height above the liquid level. To this end the holder is connected to a reservoir for receiving some of the liquid. This reservoir collects the sorbate during condensation and, conversely, also ensures that liquid is always supplied to the vaporiser during vaporisation. In order to ensure good functioning, the lowest point of the reservoir must be no higher than the same height as the lowest point of the holder. The lowest point of holder and reservoir are connected via a line. Additionally, the holder and reservoir can also be connected at the top via a line. A vaporiser/condenser installation as described above has the advantage that it can have relatively small external dimensions for a relatively large internal vaporisation surface. The invention also relates to an energy system which is provided with a heat accumulator containing a heat-transporting substance which can be either in the liquid phase or in the vapour phase, and containing a crystalline material which exothermally absorbs and endothermally desorbs the heat-transporting substance. Systems of this type must first be charged by supplying heat to the accumulator and by cooling the vaporiser/condenser installation at the same time. When the system is completely or partially charged, the process can be reversed, for example by cooling the accumulator, as a result of which cooling occurs at the vaporiser/condenser installation. Energy systems of this type are also known. However, they have a number of less favourable characteristics which in part result from the disadvantages already described above with regard to the vaporiser/condenser installations which are used in these energy systems. In this respect also, the invention offers an improvement to this existing situation in that an energy system is provided which has a vaporiser/condenser installation as described above for the heat- transporting substance, which installation is connected via a closable line to the heat accumulator. According to an advantageous embodiment provision is made in this system for the heat accumulator and the installation for the vaporisation and condensation of the liquid and vapour respectively to have a common gastight housing, the lower section of the housing being the holder and the upper section of the housing being the container for the crystalline material. With a design of this type it can be reliably ensured that a specific atmosphere is maintained in the interior of the system. This is important for good functioning of the system, since gases penetrating from the outside, such as ambient air, could disturb the processes occurring in the system. There is preferably a connecting piece of thermally insulating material between the hot and the cold section. By this means the temperature differences which arise between the vaporiser/condenser and the heat accumulator during use of the system can be better maintained. According to a simple embodiment, the housing is pipe-shaped. A compact design of the system possesses a housing which is provided on the inside with a partition adjoining the housing at the top and having a hole which connects to one end of a line which at the other end is connected to the space between line and housing, in which space the crystalline material is located. The other end of the line is provided with a valve, which can be operated via a magnet located outside the housing. There is now no need to make through-bores in the housing for operation of the valve, so that the gastightness of the housing is ensured in this case also. According to a second embodiment, the heat accumulator is located in a separate gastight housing which is connected via a vapour line to the top of the container. The form in which the housing is pipe-shaped has, on the inside, a concentric tube which opens into the exterior, an annular space also being present between the tubes to receive the crystalline material and, finally, the outer tube being provided on the outside and the inner tube being provided on the inside with heat exchangers, has the advantage that an appreciable heat exchange capacity is obtained. According to a third design variant, the heat accumulator is connected via a second vapour line to a separate condenser, which separate condenser is connected by means of a liquid line to the holder or the reservoir. The vapour escaping from the heat accumulator during charging of the system is transferred via the second vapour line to the condenser, where it condenses. The liquid is fed from the condenser to the vaporiser/condensor installation. In order to be able to alternately charge and discharge the system, each vapour line is connected by its own valve to the heat accumulator. When charging the system the valve in the vapour line for the condenser is open and that for the vaporiser/condensor installation is closed, and vice versa when discharging the system. If each valve is a spring-loaded valve, the direction of the spring loading of which being counter to the vapour flow direction, the opening and closing of the valves can be controlled entirely automatically as a function of the pressures generated in the system. In a fourth embodiment there are two heat accumulators which are connected in parallel to two vapour lines, one of which is connected to the condenser and the other to the vaporiser/condensor installation. If, with this arrangement, the heat exchangers interacting with the heat accumulators can be operated coupled together, so that alternately one heat accumulator is cooled and the other is heated, a continuous operation of the vaporiser/condensor installation can be obtained. In this case this installation can provide continuous cooling. Some embodiments of the invention will be explained below, with reference to the drawing. Fig. 1 shows one embodiment of an energy system provided with a vaporiser/codensor installation according to the invention. Fig. 2 shows a second embodiment. Fig. 3 shows a third embodiment. The energy system shown in Fig. 1 has a pipe-shaped housing 1, containing a container 2 for crystalline material (heat accumulator) and a vaporiser/condenser installation containing a holder _. . Container 2 and installation 3 are separated from one another by a partition 4, to which a line is connected. Via valve 6, the line 5 offers a connection between container 2 and holder 3- Both container 2 and holder 3 are provided with known heat exchangers (not shown). Holder 3 is provided on the inside with a capillary structure in the form of a gauze 1, fitted on the inner wall of holder 3« Holder 3 can also be provided with support elements 8, which are also covered with gauze 7« The gauze 7 extends above and below the liquid level 9- The holder can, for example, have a diameter of 10 mm and a height of 500 mm. Holder 3 is connected via line 10 to a reservoir 11, in which liquid can also be present. By means of this reservoir 11, the fluctuations in the height of the liquid level 9 can be kept under control when operating the system. This means that a significant portion of the gauze can always be kept above the water level, which is advantageous if the vaporisation and condensation are to proceed smoothly. In order to restrict the fluctuations in height even in the case of a relatively large amount of liquid, the cross-section of the reservoir parallel to the horizontal is chosen to be as large as possible. The reservoir can, for example, be constructed as a horizontal copper tube having a diameter of 100 mm and a length of 400 mm. By means of line 12 with valve 13. the tops of holder 3 and reservoir 11 can be connected to one another. In the charged state of the system, the reservoir can contain a large proportion of the sorbate, for example 20 to 80% . Valve 6 can be operated by means of a magnet 14, which is located outside the housing 1. Thus, the gets-tightness of the housing 1 can be maintained. Valve 6 can optionally be positioned at an angle, in order to promote the opening by means of the magnet. A coil -\2 is located in the annular space and spirally extends between both pipes. Thus, an efficient heat transfer between the annular space and the exterior can be ensured. In the alternative embodiment shown in Fig. 2 the container 14 of the heat accumulator and the holder 15 of the vaporiser/condenser installation are placed alongside one another and connected by a line 16. It is true that this design is less compact, but it does have the advan¬ tage that a more intense heat exchange can be obtained with the heat accumulator. This is achieved in that a heat exchanger 17 and 18 respectively can be fitted both on the outside and on the inside of the container 14. The holder 15 is also provided with a heat exchanger 19, while it is also connected to the reservoir 20 already described. The third embodiment shown in Fig. 3 shows an energy system in which two heat accumulators according to the invention, 21 and 22, are used. The heat accumulators 21 and 22 are connected in parallel. Via vapour line 23 they are both connected to a condenser installation 2k . Via a vapour line 25 they are connected to a vaporiser installation 26. Each heat accumulator is provided with a crystalline material 27, while the lines 23, 2 are connected by means of spring-loaded valves 28, 29 and 30, 3 respectively to the space in which the crystalline material 27 is present. The heat accumulators 21, 22 are both provided with heat exchangers 32, 33 having a pipe system 3^ and 35 respectively. The two pipe systems ~ι , 35 can be connected to one another by means of four-way valves 36, 37- In the situation shown in Fig. 3» the heat accumulator 22 is heated, that is to say it is charged, while the heat accumulator 21 is cooled, that is to say the latter is discharged. The heat liberated during cooling of heat accumulator 21 is released by a heat exchanger 4l. Heat accumulator 22 is heated from an external source by a liquid having a temperature of 95 * C. The vapour liberated during charging of heat accumulator 22 leads to an increase in pressure in the space in which the crystalline material is present, as a result of which valve 31 is pressed closed and valve 29 is pressed open. The vapour then flows through the vapour line 23 to condenser 24, where it condenses. The condensate 38 then flows to the reservoir 39. which, in turn, is again connected to the vaporiser/condenser installation 26. The liquid is vaporised again in this installation and the vapour is fed via line 25 to the heat accumulator 21. As a result of vaporisation in the vaporiser/condenser installation 26 it is ensured that a specific pressure always prevails in line 25- In combination with the vacuum generated in heat accumulator 21 as a consequence of the discharging thereof, the vapour being absorbed in the crystalline material and a reduction in pressure occurring in the space in which said material is present, valve 30 is pressed open. By this means fresh vapour can always enter into the heat accumulator 21. This continues until the heat accumulator 21 has been discharged. The heat accumulator 21 is more or less discharged at approximately the same time as the heat accumulator 22 is charged. This means that no further vapour can be absorbed in the crystalline material in the heat accumulator 21, so that the pressure in this space becomes equal to that in line 25. The spring valve 30 then closes and the spring valve 28 opens as a result of the increased pressure in the space in the heat accumulator 21 and the relatively low pressure in the vapour line 23 as a consequence of the condensation in condenser 24. During this operation the four-way valves 36, 37 are switched over, so that heat accumulator 22 is now cooled and the heat accumulator 21 is heated. During this entire process alternate heating and cooling of the heat accumulators thus oc¬ curs, while a continuous flow of vapour through the lines 23, 25 takes place. Furthermore, condensation takes place continuously in the condenser 24, while vaporisation occurs continuously in the vaporiser/condenser installation 26.

Claims: CLAIMS 1. Installation for the vaporisation or condensation of a liquid or vapour respectively, provided with a holder for the liquid with means for supplying or removing heat, characterised in that the holder is provided with a capillary structure which extends above and below the liquid level. 2. Installation according to Claim 1, in which the capillary structure consists of one or more layers of fine-mesh gauze. 3« Installation according to Claim 1, in which the capillary structure consists of layers of fine-mesh and coarse-mesh gauze. 4. Installation according to one of the preceding claims, in which the capillary structure is applied to the inner wall of the holder. 5. Installation according to one of the preceding claims, in which the vessel contains internal support elements on which the capillary structure is applied. 6. Installation according to one of the preceding claims, in which the holder is connected to a reservoir for receiving some of the liquid. 7. Installation according to Claim 6, in which the lowest point of the reservoir is no higher than the same height as the lowest point of the holder. 8. Installation according to Claim 6 or 7. in which the lowest point of holder and reservoir are connected via a liquid line. 9. Installation according to Claim 6, 7 or 8, in which the top of reservoir and holder are connected via a vapour line. 10. Installation according to Claim 9. in which the vapour line is closable. 11. Energy system provided with a heat accumulator containing a heat- transporting substance which can be either in the liquid phase or in the vapour phase, and containing a crystalline material which exothermally absorbs and endothermally desorbs the heat-transporting substance, which heat accumulator has means for the supply or removal of heat, characterised in that the system comprises an installation according to one of the preceding claims for the heat-transporting substance, which installation is connected via a closable vapour line to the heat accumulator. 12. Energy system according to Claim 11, in which heat accumulator and the installation for the vaporisation and condensation of a liquid and vapour respectively have a common gastight housing, the lower section of the housing being the holder and the upper section of the housing being the container for the crystalline material. 13. Energy system according to Claim 12, in which holder and container are connected to one another via a connecting piece of thermally insulated material. 14. Energy system according to Claim 12 or 13, in which the housing has on the inside a partition adjoining the top of the holder, provided with a hole to which one end of a tube is connected, which at the other end is connected to the space between tube and housing, in which space the crystalline material is present. 15. Energy system according to Claim 14, in which tube and housing consist of concentric pipes which delimit an annular space. 16. Energy system according to Claim 15, in which the other end of the line is provided with a valve which can be operated via a magnet located outside the housing. 17. Energy system according to Claim 11, in which the heat accumulator is located in a separate gastight housing which is connected via a vapour line to the top of the holder. 18. Energy system according to Claim 17, in which the housing is pipe- shaped and on the inside has a concentric pipe which opens into the exterior, between which pipes there is an annular space for receiving the crystalline material, the outer pipe being provided on the outside and the inner pipe on the inside with heat exchangers. 19. Energy system according to Claim 17, in which the heat accumulator is connected via a second vapour line to a separate condenser, which separate condenser is connected by means of a liquid line to the holder or to the reservoir. 20. Energy system according to Claim 19, in which each of the two vapour lines is connected by its own valve to the heat accumulator. 21. Energy system according to Claim 20, in which each valve is a spring-loaded valve, the direction of the spring loading being counter to the vapour flow direction. 22. Energy system according to Claims 20 and 22, in which two heat accumulators are provided, connected in parallel, with two vapour lines, one of which is connected to the condenser and the other to the vaporiser/condenser installations. 23. Energy system according to Claim 22, in which the heat exchangers interacting with the heat accumulators can be operated coupled together, so that, alternately, one heat accumulator is always cold and the other is heated.

Inventors: DE BEIJER HENDRIKUS ANTONIUS, KLEIN HORSMAN JAN WILLEM, DE BEIJER, HENDRIKUS, ANTONIUS, KLEIN HORSMAN, JAN, WILLEM
Applicants: BEIJER HENDRIKUS ANTONIUS DE, BEIJER RAADGEVEND TECH BUREAU, KLEIN HORSMAN JAN WILLEM, DE BEIJER RAADGEVEND TECHNISCH BUREAU B.V., DE BEIJER, HENDRIKUS, ANTONIUS, KLEIN HORSMAN, JAN, WILLEM
Application year: 1991
Main classification: F28D20
IPC codes: F28D20