Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F25/00—Component parts of trickle coolers
  • F28F25/02—Component parts of trickle coolers for distributing, circulating, and accumulating liquid
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28C—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA COME INTO DIRECT CONTACT WITHOUT CHEMICAL INTERACTION
  • F28C1/00—Direct-contact trickle coolers, e.g. cooling towers
  • F28C1/12—Arrangements for preventing clogging by frost
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F27/00—Control arrangements or safety devices specially adapted for heat-exchange or heat-transfer apparatus
  • F28F27/003—Control arrangements or safety devices specially adapted for heat-exchange or heat-transfer apparatus specially adapted for cooling towers
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
  • Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
  • Y02B30/70—Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating

Definitions

• the present invention relates to atmospheric refrigerants comprising an exchange body (constituted by a trickling structure), a water distribution network placed above the exchange body and provided with valves supplying each of the jets of water placed above a respective fraction of the exchange body so as to constitute isolable cooling cells, and means for collecting the water which has passed through the exchange body and pumping water to the distribution network.
• Such refrigerants are used in industry when it is necessary to remove heat and there is not a sufficient body of water for direct exchange with it.
• such refrigerants are used in thermoelectric power stations to cool the main condenser and / or the auxiliary circuits of the power station.
• This problem is particularly acute when, as is frequently the case, there may be a conjunction of a very low air temperature and a reduced thermal power, much lower than the nominal power of the refrigerant. This situation can in particular occur for the refrigeration of plant auxiliaries.
• the power dissipated during operation can, for long periods of time, be less than 10% of the maximum power for which the atmospheric refrigerant is provided.
• the present invention aims to provide an atmospheric refrigerant of the type defined above which better meets those previously known than the requirements of practice with regard to the reduction of the risk of freezing. For this, it proposes in particular to reduce the increase in hydrostatic pressure caused, on the jets of the cells remaining in service, by sending to these jets a nominal flow rate and this by avoiding the addition of active means, this i.e. requiring a remote control and / or energy electrical implementation.
• the invention provides in particular an atmospheric refrigerant of the type defined above, characterized in that it comprises static means for automatic limitation of the increase in the hydrostatic head (or head) applied to said nozzles as soon as this charge exceeds a determined value, greater than the value reached when all the cells are in service, constructed so as to derive a fraction of the water flow rate brought to the distribution level as soon as the determined value is exceeded.
• said static means comprise a weir interposed between a water tower, which is supplied by the pumping means and which supplies the distribution network by a collector and return pipes bypassing the sprinklers which remain in service , said weir being at a level corresponding to said determined value.
• Such a refrigerant may further comprise a bypass line to the collection means, having a high point which may be situated at a level higher than that of the inlet manifold of the distribution network and lower than that of the spillway so that a bypass flow begins to occur even before the determined value is reached.
• This pipe can be of very small section, because it only has the aim of avoiding a dead collector arm.
• the refrigerant comprises at least one auxiliary network for distributing water in at least some of the cells, divided into several fractions each connected to auxiliary nozzles, each assigned to a respective cell and each supplied in parallel with the respective fraction of the main network, said auxiliary network being provided to supply the auxiliary nozzles only when the hydraulic head reaches a level fixed by a high point of said network auxiliary.
• FIG. 1 is a block diagram showing a possible constitution of the means for exchanging an atmospheric refrigerant implementing a first embodiment of the invention
• FIG. 2 is a diagram in elevation, showing a possible embodiment of the invention in a forced draft exchanger
• FIG. 3 similar to Figure 2, shows another possible embodiment, usable in particular on a natural draft exchanger
• FIG. 5 shows yet another possible embodiment of the invention, applied to an atmospheric heat exchanger with natural draft
• FIG. 6 is a top view of the distribution networks and the exchange body of the atmospheric refrigerant of Figure 5.
• the heat exchange means and the hydraulic circuit shown diagrammatically in FIG. 1 can in particular equip an atmospheric refrigerant with natural draft, comprising a chimney not shown, although they are also adaptable to a forced draft refrigerant.
• They include a water tower 10 in which the water to be cooled is sent by one or more pumps 12.
• the water tower supplies at least one collector 14 to which as many branches are connected as there are cells capable to be decommissioned separately.
• Each branch has a valve 16, usually remotely controlled. It feeds distributed nozzles, such as 18, placed above an exchange body 20 on which the poured water streams and cools down in contact with the air in ascending circulation according to the arrows f.
• the cooled water is collected in a basin 22 where it is taken up by circulating pumps 24 which send it to an exchanger where it heats up before returning to the water tower.
• pumps 12 and 24 in cascade, the same pump can be used.
• static means which reduce the hydrostatic pressure applied to the remaining nozzles when some of the valves are closed, include a weir 26.
• h 0 a fraction of the hot water supplied by the pumps 12 flows into a channel 28 from which a conduit 30 brings it directly to the basin 22.
• the flow rate of the overflow blade increases in proportion to the square root of its thickness ⁇ h. Consequently, provided that the weir has a sufficient length, the load can be limited to a value little greater than h 0 .
• the static means may further comprise a discharge line 32 or more.
• Line 32 brings water from the collector 14 directly to the basin 22 (solid line) or to channel 28 (dashed lines) when the hydrostatic head exceeds a level h 1 ! lower than h 0 , but greater than the hydrostatic charge given by the pumps 12 when all the cells are in service.
• the pipe has a bend 34 forming a high point at level h ′.
• a vent 36 is arranged at the high point. It opens at a level higher than h 0 , in order to prevent water from overflowing through the vent.
• the elbow can also prevent the channel 28 from replenishing the collector in certain cases.
• the cells 20 can be distributed angularly. This is generally the case in large refrigerants with natural draft. They can also be distributed along a collector 14. In this case it is desirable for the pipe 32 to extend the collector, in order to protect the latter. Such aligned cells can flow into a channel opening into a basin from which water is extracted by the pumps 24. The pipe 32 then advantageously opens at the end of the channel furthest from the basin.
• the manifold 14 is directly supplied directly by the pumps 12.
• the weir 26 is then located at the opposite end of the manifold.
• the atmospheric refrigerant according to the embodiment shown in FIG. 2, where two cells are completely shown, is with forced draft and comprises, for each cell, a suction fan 40.
• the air enters the cell between deflectors 42, circulates in the exchange body 20 against the flow of water, and is sent to the outside by the fan 40.
• the inlet valve 16 of each cell feeds a main network of distribution tubes fitted with nozzles 18, generally all located at the same level, placed above the exchange body 20.
• the water flowing from the exchange body is collected in a tank 44 which a channel 46 puts in communication with a general basin.
• the static means comprise an auxiliary network of tubes supplied by a distributor 48 supplied by an upward connection 50 on the main network, located downstream of the valve 16.
• the distributor has a high point at a level h 1 # which is connected to the atmosphere by a vent 36 opening to a level h 2 if the high point is located.
• the nozzles 52 of the auxiliary network are placed above the nozzles 18 and the distributor 48 is placed above the level of the distributor of the main network. This arrangement (as well as an arrangement in which the nozzles 52 would be below the nozzles 18) makes it possible to reduce the pressure losses on passing through the air.
• Figure 3 shows only the distribution networks of a cell constituting a variant of that shown in Figure 2.
• the exchange body of the cell is split vertically into two superimposed runoff volumes 20a and 20b.
• the auxiliary distribution network is placed so as to only spray the lower runoff volume 20b.
• This arrangement increases the effectiveness of the device against freezing.
• the water tower supplies channels 54, each assigned to a cell, by means of respective valves 16.
• the main distributor leaves from the bottom of the channel 54.
• the auxiliary distributor 42 is supplied by the channel from the moment the level in the channel exceeds a height h 3 . In this case, it is no longer necessary to provide a high point and a vent on the distributor 48, the outlet to the open air of the channel 54 taking the place.
• FIGS 5 and 6 show a possible embodiment of the invention on a natural draft refrigerant, having a chimney 56 of conventional constitution.
• This chimney rests on the ground by a network of beams leaving free an annular passage of air intake.
• the chimney contains an exchange body, formed for example by battening.
• This exchange body is separated by partitions 60 into several cells.
• the partitions 60 delimit a central cell and six peripheral cells.
• the partitions 60 which are substantially sealed, extend vertically from the bottom of the exchange body to the top of the tubes of the water distribution networks.
• a central water tower 10 supplies the part of the network specific to each cell by galleries or pipes provided with inlet valves 16. These pipes feed distributors having a constitution which may be one of those described above. above.
• each of the peripheral cells comprises on the one hand a main distributor, on the other hand, an auxiliary distributor 48 having a high point, the general constitution possibly being that shown in FIG. 2.
• auxiliary network When, as in the case of FIGS. 5 and 6, only some of the cells comprise an auxiliary network, it is the unequipped cells which must be isolated first when it becomes necessary to combat the gel.
• the invention is susceptible of numerous other embodiments.
• an upward connection is provided downstream of at least some of the valves 16 It supplies auxiliary sprinklers.
• the top point of the nozzle must imperatively be less than hsted. However, it must be above the level reached by the water in the water tower 10 when all the cells are put into service at the same time by opening the valves 16.
• nozzles downstream of the inlet valve It is also possible to provide several nozzles downstream of the inlet valve, with high points at different heights. It is also possible to equip an auxiliary network intended to combat freezing only the most sensitive of the exchange body, that is to say those which are crossed first by the cold air.
• the invention is applicable to any of the types of known atmospheric exchangers and in particular as well to atmospheric refrigerants with cross current as with those against the current.
• the invention can be combined with means intended to combat the formation of frost in the access openings, for example by pouring a curtain of uncooled water on the passage of air, at the atmospheric refrigerant inlet.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
• Other Air-Conditioning Systems (AREA)

Applications Claiming Priority (3)

Publications (1)

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ID=9466763

Family Applications (1)

Country Status (6)

Cited By (1)

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• 1994
  • 1994-09-07 FR FR9410717A patent/FR2724220A1/fr active Granted
• 1995
  • 1995-09-05 CN CN95191005A patent/CN1136839A/zh active Pending
  • 1995-09-05 WO PCT/FR1995/001148 patent/WO1996007863A1/fr not_active Ceased
  • 1995-09-05 PL PL95314233A patent/PL314233A1/xx unknown
  • 1995-09-05 CA CA002175931A patent/CA2175931A1/fr not_active Abandoned
  • 1995-09-05 EP EP95929928A patent/EP0727033A1/fr not_active Withdrawn

Non-Patent Citations (1)

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