Claims
- 1. A method of cooling at least one enclosure comprising the steps of:
- circulating a diphasic mixture of the same substance in melting equilibrium in a main loop, said diphasic mixture comprising a liquid portion and a solid portion of said liquid in a frozen state;
- diverting at least part of only said liquid portion to said at least one enclosure in a corresponding diverted loop such that said solid portion remains in said main loop;
- transferring heat from said at least one enclosure to said liquid in said corresponding diverted loop;
- returning said heated liquid in said corresponding diverted loop to said main loop; and
- regulating the flow and cooling of said diphasic mixture to maintain said mixture in a homogeneous state at substantially all points in the main loop.
- 2. The method of claim 1, wherein the heated liquid in the corresponding diverted loop is returned tot he main loop immediately upstream from the point on the main loop where the liquid is diverted.
- 3. The method of claim 1, wherein the heated liquid in the corresponding diverted loop is returned to the main loop immediately downstream from the point on the main loop where the liquid is diverted.
- 4. The method of claim 1, wherein the temperature of the diverted liquid is measured and the flow rate of the diverted liquid in the diverted loop is regulated based upon said measured temperature.
- 5. The method of claim 1, wherein the liquid portion and solid portion of said diphasic mixture are water and ice respectively.
- 6. The method of claim 1, wherein the at least one enclosure is a plurality of enclosures.
- 7. The method of claim 1, wherein after said step of returning said heated liquid in said corresponding diverted loop to said main loop, at least part of said liquid portion including at least part of said heated liquid is cooled by said solid phase of said diphasic mixture.
- 8. A cooling device comprising:
- a main loop for transporting a diphasic mixture in melting equilibrium, said mixture comprising a liquid portion and a solid portion;
- a primary heat exchanger in said main loop for cooling said diphasic mixture by indirect heat exchange with a refrigerating fluid different from the diphasic mixture;
- at least one diverted loop having an inlet and an outlet connected to said main loop, said at least one diverted loop comprising a secondary heat exchanger; and
- means for ensuring that at least part of only said liquid portion is diverted to said diverted loop, said means for ensuring being at said connection between said inlet of said diverted loop and said main loop.
- 9. The device of claim 8, wherein said outlet of said diverted loop is connected to said main loop immediately downstream from said inlet of said diverted loop in the direction of flow of said diphasic mixture in said main loop.
- 10. The device of claim 8, wherein said at least one diverted loop comprises a plurality of diverted loops connected to said main loop wherein said outlet of one of said diverted loops is immediately upstream from said inlet of another one of said diverted loops in the direction of flow of said diphasic mixture in said main loop.
- 11. The device of claim 8, further comprising a tank in fluid communication with said primary heat exchanger for generating and storing said diphasic mixture, said tank being connected to said main loop by an inlet and an outlet.
- 12. The device of claim 8, wherein the main loop is disposed on at least two different levels with at least one corresponding substantially vertical duct between upper and lower said levels.
- 13. The device of claim 12, further comprising a lower syphon disposed between the bottom of said substantially vertical duct and said lower level of said main loop.
- 14. The device of claim 12, further comprising an upper syphon disposed between said upper level of said main loop and the top of said substantially vertical duct, said upper syphon having a smaller cross-section than the cross-section of said main loop.
- 15. The device of claim 13, further comprising a reinjection loop having an inlet connected to the main loop downstream of said lower syphon and said reinjection loop having an outlet connected at a bend between said upper level of said main loop and said substantially vertical duct, said reinjection loop inlet having a means for ensuring the passage of only a liquid portion of said diphasic mixture.
- 16. The device of claim 8 wherein the primary heat exchanger comprises a refrigerating fluid for cooling said diphasic mixture.
- 17. The device of claim 8, wherein said at least one diverted loop is a plurality of loops.
- 18. The device of claim 8, wherein said secondary heat exchanger is within an enclosure for cooling said enclosure.
- 19. The device of claim 8, further comprising means for regulating the flow rate and rate of cooling of said diphasic mixture to maintain the diphasic mixture in a homogeneous state.
- 20. The device of claim 8, further comprising a means for measuring the temperature of said liquid portion within said diverted loop, and means for regulating the flow rate of said diverted liquid portion based upon the temperature measured by said temperature measuring means.
- 21. The device of claim 8, wherein the liquid portion and solid portion of said diphasic mixture are water and ice respectively.
- 22. The method of claim 1, wherein the diphasic mixture is cooled by indirect heat exchange with a refrigerating fluid different from the diphasic mixture.
Priority Claims (1)
| Number |
Date |
Country |
Kind |
| 89 15278 |
Nov 1989 |
FRX |
|
BACKGROUND OF THE INVENTION
The present invention relates to the transfer or distribution of cold in a plurality of enclosures to be cooled, from a single and same intermediate cold-bearing fluid which is itself cooled by heat exchange with a unique refrigerating source.
The term "enclosure" is understood generally to refer to any heat source, that is to say any environment likely to be affected directly or indirectly by heat. It can be a substantially closed enclosure, such as a cool room, a premises for industrial or domestic use to be air conditioned, such as a dwelling house. It can also be an environment to be cooled contained in a recipient or a said enclosure, such as a liquid or fluid load; in this respect, in order to describe the present invention by way of example, reference will be made to the vinification field and more precisely to the cooling of fermentation vats, in order to control or thermally master this biological process.
According to U.S. Pat. No. 3,247,678, a cold transfer method such as mentioned above has been described for conditioning the air in several premises or separate enclosures. According to this method:
an essentially closed circuit is established, for the intermediate circulation of a cold-bearing fluid, namely a brine
this fluid is cooled by a direct heat exchange between the cold-bearing fluid in liquid form and a refrigerating fluid, also in liquid form, butane in this instance
for each enclosure to be cooled, partial current of the cold-bearing fluid is tapped from the intermediate circulation circuit, the environment to be cooled in the enclosure is cooled by heat exchange with the tapped partial current, and the reheated partial current is returned into the intermediate circulation circuit, downstream from the tapping of the latter partial current taken from the cold-bearing fluid, in the direction of the circulation of the latter.
According to this method, the cooling power supplied by the refrigerating fluid, with respect to the total cooling power consumed in the plurality of enclosures to be cooled, is adjusted in such a way as to have a cold-bearing fluid in circulation comprising two phases of water in melting equilibrium, in this instance brine and ice, mixed with each other homogeneously, and this being the case at least in the section of the circulation circuit from which the partial cooling currents are tapped or injected.
Such a cooling method has several disadvantages.
Firstly, each tapped circuit provides the circulation of a partial current of the diphasic cold-bearing fluid, of relatively low flow rate, towards the enclosure to be cooled. Experience shows that under these conditions ice crystals are likely to agglomerate and lead to complete obstruction of each tapped circuit, in particular in functioning periods where the cooling power supplied can temporarily exceed the total cooling power consumed. Such an obstruction can also result in the deterioration of the units for the circulation or control of the tapped partial current flow rate, such as pumps, valves, etc.
Then, the cooling power being able to be transferred per unit volume of cold-bearing fluid circulating in the intermediate circuit appears limited since, finally, a portion of the cold transferred to the various enclosures results in the reheating of the brine; the cold-bearing fluid in fact arrives in the reheated liquid state at the intake of the circulation pump.
Finally, the return of each tapped circuit, downstream from the tapping of the latter tapped circuit on the intermediate circulation circuit, reduces the flow rate available for the following tapped circuits, and therefore the negative kilo-calories available for the cooling of the following enclosures. There is therefore a kind of progressive exhaustion of the available cold, in the direction of circulation of the cold-bearing fluid. Furthermore, this tapping method results, in the branch of the intermediate circuit supplying the various tapped circuits, in a cold-bearing fluid flow rate which is much lower downstream of the various tapping points than upstream of the latter. This lower flow rate increases the risk of obstruction of the intermediate circuit itself, by the gain in mass of the different particles of the solid phase of the cold-bearing fluid.
The present invention aims at overcoming all these disadvantages.
The subject of the present invention is a method and a device, of the preceding type, allowing the availability of a maximum of cold per unit volume of cold-bearing fluid in circulation, due to the absorption of latent heat of melting of the said fluid, over practically the entire path of the intermediate circuit of the said fluid in the diphasic state.
Another subject of the invention is a method and a device allowing a circulation of the cold-bearing fluid, without obstruction by the solid phase of the said fluid, in each tapped circuit, but also in all parts of the intermediate circuit.
Another subject of the invention is a method and device ensuring a regular distribution of the negative kilo-calories available in the cold-bearing fluid, in all of the tapped circuits of the partial flows of the said fluid.
According to the invention and in combination:
a) the intermediate circulation circuit consists in a free flowing loop for carrying the cold-bearing fluid, that is to say a loop without interruption or passage of the fluid through such and such a unit other than a circulation pump or a control valve, for example an intermediate storage capacity or a filter; and the cooling power supplied, the total cooling power consumed and the circulation flow rate in the loop are adjusted in such way as to obtain at all points of the loop a homogeneous diphasic state in melting equilibrium
b) each partial current is tapped, solely on the liquid phase of the cold-bearing fluid in circulation in the loop; the reheated liquid partial current is returned into the same loop.
Preferably, in the direction of circulation of the cold-bearing fluid in the loop, each reheated partial liquid current is returned immediately downstream or upstream of the tapping of the same current, that is to say respectively upstream of the tapping of the next partial current on the same loop, or downstream from the return of the tapping of the preceding partial current.
Due to the choice according to the invention;
a current of relatively large flow rate of the cold-bearing fluid in the diphasic state circulates in the intermediate circuit
each tapped circuit is fed by a tapping on the liquid phase of the cold-bearing fluid, the tapped and reheated partial current being returned beside the tapping or injection of the same tapped liquid current
each reheated partial current, in the liquid state, reinjected in the intermediate circulation circuit, is immediately cooled, by the melting of the solid phase of the cold-bearing fluid, before the latter flows in part in the following tapped circuit or in the same tapped circuit.
In this way, for a relatively limited dimensioning of the intermediate circuit, particularly with regard to cross-section, it appears possible to carry a relatively large quantity of negative kilo-calories to the different enclosures to be cooled and for this to be carried out without obstruction of the different circuits, and with a balanced distribution of the negative kilo-calories to the different tapped circuits.
Preferably, the cold-bearing fluid comprises ice in pasty form, in melting equilibrium in water. Given that the ice floats on top of the water, turbulent conditions are established in the cold-bearing fluid in order to maintain its pasty form, with the dissolving of the ice.
US Referenced Citations (12)
Foreign Referenced Citations (2)
| Number |
Date |
Country |
| 0262688 |
Dec 1988 |
DDX |
| WO8602374 |
Apr 1986 |
WOX |
Patent Grant
5123262
