MXPA00002728A - Rotating disk evaporative cooler - Google Patents

Abstract

A tank holds a pool of liquid coolant in which spaced, rotatable disks are partially submerged. An air flow is established over exposed portions of the disks, preferably parallel thereto, whereby coolant adhering to the disks upon rotating out of the coolant pool is partially evaporated and the disks and remaining adhering coolant have their temperature lowered and serve to cool the coolant pool upon reentry into the pool from the air space above. A fluid to be cooled is passed through tubes mounted in the tank, below the surface of the liquid coolant, parallel to the surfaces of the disks. Adjacent rows of tubes define spaces therebetween, each of which receives the submerged portion of at least one disk. The evaporative cooler may be used in a refrigeration apparatus in combination with a compressor and an evaporator.

Description

ROTARY DISC EVAPORATOR COOLER BACKGROUND OF THE INVENTION Field of the Invention This invention is a new type of evaporator cooler for air conditioning and refrigeration. Prior art There are three basic types of condensers in air conditioning and refrigeration; cooled with air, cooled with water, and cooled by evaporation. The most common type of condenser is air cooled, which is almost exclusively residential equipment and small stores. These condensers usually consist of a copper pipe coil with internal coolant and aluminum blades on the outside of the tubes. A fan expels air over the coil to expel heat into the atmosphere. This type of capacitor is simple and requires little maintenance, but is relatively inefficient. Water cooled condensers are the second most common type. Water cooled condensers are usually used with centrifugal and screw extinguishers found in large commercial and industrial premises. The normal arrangement is a tube heat exchanger covered with cooling water that circulates inside the tubes and condensing refrigerant on the outside. The water for this type of condenser is normally cooled by a separate cooling tower. A cooling tower consists of a water spray system that distributes water over the filling material. A fan moves air over the wet fill to cool the water. This system is normally more efficient in terms of energy, with condensation temperatures of -6.6 to -1.1 degrees Celsius less than a condenser cooled with comparable air. On the other hand, water-cooled condensers and associated cooling towers usually require much more maintenance, and are more complicated, and must be assembled in the field instead of being shipped as a single package. The third type of condenser is cooled by means of an evaporator. An evaporator condenser combines a cooled condenser with water and a cooling tower in a single package. Existing evaporator condensers are usually found in large commercial or industrial refrigeration systems and are rarely used in air conditioning applications. Fig. 1 shows a conventional arrangement for the third type, i.e. an evaporator condenser. A pump 10 draws water from a basin 12 and supplies it to a spray manifold 15 from which it is sprayed onto the tubes 14 containing condensing coolant. A fan 16 moves the air entering C through the water spray and moistens the tubes 14 to remove the heat thereof by means of an evaporator. The air that comes out of the D condenser goes through a fogging remover 18 that removes most of the water droplets. Although Fig. 1 illustrates a direct blow-off evaporator condenser, an evaporator condenser of the direct extraction type is also known in the art, wherein the fan is located downstream of the tubes and draws it out through the tubes and it sprinkles The water pump and spray pipe of a system such as in Fig. 1 creates two major maintenance problems. First these are vulnerable to freeze damage. A partial solution to this problem is to place the pool and the pump inside a heated construction, but this arrangement makes the installation more difficult. The second problem is that the pump and the pipe can be easily clogged with dirt. Water strainers are used to reduce this problem, but these can also become clogged and require frequent maintenance. The evaporator condensers and current cooling towers also had major problems as sources of Legionnaires' disease, a potentially fatal type of pneumonia. Without a regular treatment of water, heat, humid conditions in the condenser can withstand the growth of legionella, the bacteria that causes Legionnaires' disease. Although legionella is common in freshwater ponds and other surface waters, it does not cause pneumonia unless it is inhaled through the lung. A real problem with conventional evaporator condensers and cooling towers is that the water spray creates a fogging of water droplets that can be easily inhaled. Evaporator condensers have been implicated in several outbreaks of Legionnaires' disease. Evaporator condensers and cooling towers have inherent efficiency advantages compared to air-cooled equipment. For the air-cooled equipment, the limit air temperature is the dry focus temperature outside. For evaporator systems, on the other hand, the limit is the wet bulb temperature which can be -6.6 to 4.4 ° C colder. In addition, the heat transfer between air and a wet surface is several times larger than for a dry surface. The airflow requirements are also smaller with evaporator heat exchange, since water vapor increases the enthalpy (energy content) of the air more. These factors mean that an evaporator condenser or cooling tower can give much lower condensing temperatures than the reduction size and fan power requirements purchased with air-cooled systems. Despite the improved evaporator heat exchange efficiency, there has been a gradual move away from water cooled condensers and evaporator condensers. The residential conditioning systems in the early 1930s were usually cooled with water, considering that since the 1950s almost exclusively they had been cooled with air. The 150-tonne cooling loads that were normally handled with a water-cooled extinguisher in the 1960s now usually have an air-cooled equipment. These changes are driven by concerns about maintenance costs associated with water-cooled equipment. The theoretical analyzes and simulation of evaporator condensers, cooling towers, and fluid coolers have been carried out by Webb and Villacres, "Performance Simulation of Evaporative Heat Exchangers - (Cooling Towers, Fluid Coolers and Condensers)." AlChE Heat transfer Symposium, vol. 80, 1984. The theoretical bases are well established, and their expected loading simulations within +3% for a wide variety of air intake conditions. In addition, there are several documents which attempt to determine the energy saving potential of condensers cooled by evaporation. Guinn and Novell "Operating performance on a Water Spray on an Air Type Condensing Unit", ASHRAE Transactions, vol. 87, part 2, 1981, reports tests of a water spray device commercially available in the air-cooled condensing unit of an air conditioner of the three-ton sectional system. They found that the energy input of the compressor decreases by 5% to 9%, the cooling capacity increases by 4.4% to 8.8%, and that the energy efficiency ratio (REE) of the system was improved by 12% to 19% depending on the thermodynamic state of the inlet air. The sprayer used 51.5 liters of water per hour. The problems encountered were the influx of water from the tubes and falsification and corrosion of the tubes. Markoski, M. J. "Exergetic Analysis of Water Spray Augmentation of Air Cooled Condensers", Proceedings of 19 th Intl. Congress of Refrigeration, Illa, 1995, provides a brief exergetic analysis of this method of heat transfer increase. Leidenfrost, W., and B. Korenic, "Evaporative Cooling and Heat Transfer Augmentation Related to Reduced Condenser Temperature", Heat Transfer Engineering, vol. 3, 1982, tested evaporator cooling for reducing condenser temperatures. It was shown that the analytical model agrees with the experimental data. An interesting test showed that, with the heat regime of the condenser kept constant at 300 W (71.68 cal / sec), the condensation temperature can be lowered from 44.6 ° C with dry surfaces up to 24.4 ° C with wet surfaces. Also, the same data set showed that it can be increased from 300 W (71.68 cal / sec) to 2280 W (554.6 cal / sec) when water spray is applied. Although the increase in the heat removal regime is partially out of place by increased air pressure drops, the net effect is still very positive, with a possible decrease in energy consumption of the 50% air conditioner.

SUMMARY OF THE INVENTION Accordingly, it is an object of the invention to reduce or eliminate problems associated with prior art evaporator coolers and to provide a more competitive evaporator cooler with air cooled equipment. Another object of the present invention is to save energy by reducing the compressor energy required by a refrigeration cycle using an evaporator cooler according to the present invention as a condenser. In order to carry out the above objectives the present invention provides a liquid cooler reservoir with the upper surface of the reservoir in contact with air. A rotary arrow is mounted on the upper surface of the reservoir with its longitudinal axis approximately parallel to the upper surface of the reservoir and is driven by rotation by any suitable rotary impulse means. At least one wheel member is mounted and extends radially from the rotary shaft and is partially submerged within the reservoir. Therefore, just as the member of the wheel rotates a given point on it, successively enters the tank, leaves the tank in the air and enters the tank again continuously, in a repetitive cycle, while the arrow tour. In this way, the liquid cooler in the tank adhered to the wheel evaporates in the air when leaving the tank and when it enters the air, thus cooling the wheel and remaining liquid coolant attached to it. The cooled wheel and the remaining sticky liquid cooler, in turn, serve to cool the tank upon re-entry. The present invention can be used to cool any body of the liquid such as a pool, with or without a fan, by establishing an air flow on that portion of the wheel of the wheel member exposed to the anterior air of the upper surface of the reservoir, v. gr., a pool. However, as will be explained later, the presently preferred application for the present invention is used as an evaporator condenser in a refrigeration system. The presently preferred embodiment has a plurality of wheel members, eg, disks, spaced apart along the rotating shaft which is mounted on the liquid cooler tank, eg, water, the disks which extend approximately perpendicular in relation to the surface of the cooler reservoir and partially submerged therein. An air flow is provided by a fan and is directed over the portions of the disks that extend over the refrigerator reservoir to evaporate the refrigerant and by means of which the portion of the refrigerant which remains adhered to the disks is cooled while it returns to enter the cooler reservoir. The air flow is preferably directed parallel to the surfaces of the rotating discs. The rows of tubes are mounted within the tank, posterior to the surface of the cooler tank, and are oriented parallel to the surfaces of the rotating discs with a rotating disc extending in each space defined between the rows of adjacent tubes. While the main use for such a mode would be as a condenser, it could also be used to cool other fluids in addition to the condensing refrigerant. For example, water or antifreeze solutions can circulate through the tubes. As noted above, the presently preferred use of the evaporator cooler of the present invention is a refrigeration system. In such a refrigeration system a refrigerant, at least partially in the vapor state, is fed by a compressor through the condensation evaporator cooler in the present. A liquid cooler is then passed through an evaporator and returned at least partly in a vapor state to the compressor. The evaporator cooler of the present invention has the following advantages purchased from conventional evaporator condensers: 1) without water pump or spray system to clog or freeze, 2) greatly reduced splash-virtually eliminates the risk of transmitting legionella, 3 ) reduced maintenance, 4) low cost, and 5) thermal mass of water in tank partially improves the efficiency of loading.

The advantages of the refrigerator of the present invention purchased with the air-cooled condensers include: 1) much better energy efficiency, 2) reduced peak power consumption, and 3) cost and competitive size. The wheel members can be flat solid discs, or corrugated discs and will usually have a diameter / thickness ratio of 30: 1-50: 1. Based on the experimental data obtained by the inventors, it is believed that a coolant film, adhered to the members of the rotating wheels while emerging from the liquid cooler and remaining on them while they re-enter the liquid cooler, serves as the primary heat transfer medium. The present invention further contemplates an evaporative cooling method using the novel apparatus of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: Fig. 1 is a schematic diagram of a direct blow type evaporator condenser of the prior art; Fig. 2 is a schematic side view of a preferred embodiment of the evaporator cooler of the present invention; Fig. 3 is a front cross-sectional view taken along the line G-G in Fig. 2; Fig. 4 is a schematic view of a corrugated disc used in the alternative embodiment of the present invention; Fig. 5 is a schematic illustration of a batch-scale apparatus according to the present invention; Fig. 6 is a graph of the heat removal rate (W) versus the angular velocity of the disk (RPM) obtained from series of tests using the apparatus shown in Fig. 5; Fig. 7 is a graph of the total heat removal (UA) regime (10"3kg / s) Fig. 8 is a lateral water graph UA (in W / K and BTU / h - ° C) ) against the angular velocity of the disc in the series of tests, Fig. 9 is a graph of heat removal rate (W) against air flow rate (in 1 / s and cfm) in the series of tests; Fig. 10 is a bar graph of the rate of heat removal for three different discs, and Fig. 11 is a schematic view of a refrigeration system using the evaporator condenser of the present invention DESCRIPTION OF THE MODALITIES PREFERRED EMBODIMENTS A preferred embodiment of the present invention is shown in Figs 2-3 where a tank 20 has a plurality of rows of heat exchange tubes containing refrigerant 22 mounted on it. Each row consists of a single tube 22 connected by T connections between a liquid collector 21 and a steam collector 23, eg, of a compressor. Each tube 22 is flexed to form plural horizontal slides 22a which are arranged vertically. A plurality of plastic heat exchange discs 24 are also mounted separately on a rotating shaft 26 driven by a motor 28. The heat exchange discs 24 each extend between the adjacent rows of heat exchange tubes 22. and partially immersed in water 30 with their centers located on the rotating shaft 26, just before the Water surfaces 30. The air is extracted in a tank 20 in E and fatigued in F by a fan 32. Therefore, an air flow path is defined between the top of the tank 20 and the surface S of water 30. Passing through the tank 20 the air increases its moisture content by evaporating water liquid which adheres as a film to the surfaces of the disks 24. The heat transfer of the discs 24 to the water in the adhesion film, such as the heat of vaporization, serves to cool the discs 24 and, more importantly, the water that remains in the film. adhesion particle. The portions of the discs 24 on the surfaces of the water 30 and the remaining water film are directly cooled and serve to cool the water 30 by re-entering the water 30 by rotation and by transferring heat to the submerged portions. Thus, the water 30 is kept at a sufficiently low temperature to effect the condensation of refrigerant vapor entering the tubes 22 submerged in the water 30 contained in the tank 20. In addition to removing the heat from the water 30, the rotating disks 24 agitate the water. The agitation of the water promotes good heat transfer between the water and the condenser tubes 22. The discs 24 are preferably made of a plastic sheet or sheet of metal coated with plastic. Several different materials for the discs were examined in experiments and a small variation in heat transfer was found. Theoretically, a material with high content of mass, high conductivity, should give better heat transfer, but the observed effects of change of disc material were small. The main factor in the choice of the disc material is the cost. A corrugated plastic material (Fig. 4) is the preferred option from the economic point of view. Instead of solid circular discs, which exhibit uniformity, interrupted surfaces, the discs may have radially extending strips to improve the agitation of the water. However, experiments have shown a small improvement in performance with a substantial increase in the energy required to spin the discs. Also, instead of corrugated discs (Fig. 4) or flat discs (Figs 2-3), circular bodies of a rectangular grid material such as those found in fluorescent light diffusers can be used, with air flow parallel to the axis of rotation of the discs. However, experiments with such rotation grids showed a large amount of spatter and increased energy was required to rotate the discs. Problems also appeared with the maintenance of a film of water on the disc material. Instead of rotating the disc clockwise, the direction of rotation of the disc with respect to the air flow can be reversed. However, while the direction of disc rotation does not make much difference in heat transfer, the lateral air pressure drops are much larger when the rotation of the disc is contrary to the air flow. Consequently, rotation of the discs in the same direction as the air flow is preferred. Experiments show that the energy required to spin the disks is easily increased with the speed of rotation. The heat transfer improved only slightly above about 20 revolutions per minute (rpm). The optimum speed for the 0.6 m diameter corrugated discs used in the tests is almost 20 to 30 rpm. Table 1 below shows usual operating parameters for the evaporator condenser of the present invention and for a conventional water cooled condenser.

Table 1: Comparison of Performance between the Random Disk Evaporator Condenser and a Condenser Cooled with Conventional Air Condenser cooled with New Air Condenser Temp. of focus in room 35 35 ° C dry Temp. ambient focus 23.8 23.8 ° C Humid Temperature 48.8 32.2 ° C condensation Expulsion of heat from 2206.4 2031.9 cal / sec condenser Air flow rate of 2500 1500 CFM condenser Ambient air enthalpy 88.78 joules / grams m Output air entrainment 98.67 joules / grams m Air enthalpy in Temp. 128.8 joules / grams m Condensation UA / total disc 80.5 grams / hour / disc Heat ejection per disc 534 Required discs 54 Disc speed 30 rpm Ventilator power 200 50 w Motor power per disc 1.5 w / disc Disc motor power 0 75 w Total power of 200 125 w Capacitor Compressor power 1960 1230 w Compressor capacity 1729 1729 cal / sec Fan power in 330 330 w interiors Net system capacity 1659 1659 cal / sec Total energy of the system 2490 1685 w System REE 0.665 0.987 cal / sec / w 32% energy saving percentage Therefore, the present invention provides a spray-free apparatus that solves problems associated with current evaporator condensers. Because the device has no spray and little or no splash, it greatly reduces or eliminates the risk of Legionnaires' disease. The removal of the pump and spray system also avoids clogging and freezing problems of the prior art systems. The liquid level switch as shown at 13 in Fig. 13, is provided to activate a solenoid valve on a hidden water line to maintain the proper water level in the tank. This valve can be located inside to eliminate problems of freezing potential. A second valve 34 can be used periodically to drain the tank in order to allow it to dry and reduce problems with false biologics. The costs for the evaporator condenser of the present invention must be competitive with air-cooled equipment. It is estimated that the energy savings that can support the initial initial cost of this system is almost 2.5 years in a humid climate.

In the evaporator cooler of the present invention it offers significant savings in peak demand. For a system of 2520 cal / sec, the savings represent more than 1 kW under usual conditions in the east of E.U.A (35 ° C of dry focus, 23.8 ° C wet bulb). The value of power generation and transmission capacity is almost $ 500 to $ 1000 / kW. These cost savings for utility could further divert the additional cost from the system. The peak savings in the western US would be even greater because the dry climate gives evaporator cooling, an even bigger advantage. To illustrate how dry climates could improve performance, a comparison is considered for Phoenix, Arizona. The design temperature is 42.7 ° C with a wet bulb temperature of 21.6 ° C. In the Phoenix desert climate, the wet bulb temperature is almost 4.4 ° C cooler than the dry bulb temperature, as opposed to almost -6.6 for the eastern US. The energy savings in Phoenix can approximate the 50% purchased with an air-cooled system.

A potential advantage of the evaporator condenser of the present invention is the thermal mass associated with the water in the tank. The fan and the disc can operate to cool the tank for as long as the compressor does not operate. For a three-ton system the mass of water in the tank could be almost 225 kg. By cooling the tank by -15 ° C, 630 Kcal of energy will be stored. This cooling corresponds to the total heat ejection for almost four minutes of compressor operation. A compressor cycle usually lasts only 10 minutes, so this energy storage would significantly decrease the average condensing temperature and therefore improve the efficiency of the system. A variable speed or two speed fan and discs would greatly reduce auxiliary power requirements to cool the tank during the cycle without operating and save additional energy. To prevent biological development in the tank, the tank should be drained frequently and allowed to dry completely. Another possibility is the use of an insecticide in turbid water to kill any biological development. Baltimore Aircoil, a manufacturer of cooling towers, sells a system that uses iodine as an insecticide for small cooling towers. An advantage of iodine is that only 0.45 kg or 0.90 of material would be required for the entire life of the condenser, which means that the unit can be shipped with a lifetime supply.

EXPERIMENTAL A series of experiments were carried out using a bench scale evaporator condenser as shown in Fig. 5, according to the present invention. The upper bench design had two discs 44 which were exposed to approximately one-half to an ambient air stream and submerged approximately in half in a water reservoir containing condenser pipe 42. When the disks 44 are rotated, these bring the water from the reservoir into the air stream like a thin film. The flow of air beyond the wet discs 44, evaporates some of the water film on the discs and the cooled water returns to the reservoir. Therefore, the rotation of the discs 44 serves a double purpose. First, it causes forced convection in the reservoir around the condenser pipe 42 which increases the transfer of heat from the condenser pipe to the water reservoir. Second, it takes the water from the reservoir relatively warm in the air vapor so that the heat of the condenser is eventually expelled into the air. The bench scale parallel row evaporator condenser consists of a water reservoir 45, tube bundle 42, air channel 46, and stirring discs 44 as shown in Fig. 5. The apparatus used cooling caused by evaporation to carry out the condensation of the refrigerant. The water tank 40 was made of a 6.4 mm thick acrylic sheet with external dimensions of 671 mm x 259 mm x 71 mm. Three rows of copper tube 42 of 7.9 mm I.D. and 9.5 mm O.D, were arranged to pass horizontally across the length of the tank, with three tubes (in the vertical column) per row. The vertical distance between the rows of 47 mm, while the horizontal space was 16 mm. Tank 40 was filled with water at a level of 85 mm above the top of the tube bundle. The reinforced acrylic edges 37 mm wide and 13 mm thick in the upper part of the tank served as a pairing surface for the air channel and as the reinforcement for the tank 40. One side of the tank 40 is provided with a copper tube on the bottom, connected to the valve 47 to drain the tank when desired. Another acrylic box 42 was used to house the stirring disks 44 and to direct the air flow of a blower 48 beyond the disks 44. Its external dimensions were 1021 mm x 419 mm x 71 mm, and it was also 6.4 mm thick. Edges similar to those on the water tank, were provided to attach the air channel to the tank. The entrance section was completely opened, and the exit was restricted to 127 mm x 57 mm central opening. The critical components of the condenser are the stirring discs 44. Aluminum and various plastics such as polypropylene and styrene were tested as disc materials. The discs 44 are partially immersed in the water reservoir, with 30-50%, preferably around 40%, of their surface area being submerged, and with the disks 44 rotating between the rows of tubes 42.

An acrylic arrow and a hard copper tube serve to connect the discs 44 and cover the motor (not shown). The aluminum discs 44 had a diameter of 610 mm, and a thickness of 1.6 mm with a 7.6 mm hole to connect the discs 44 to the driving motor. Between each pair of adjacent discs 44 there was a 102 mm plastic liner with the same hole, as well as acrylic spacers with a radius of 156 mm which is combined to maintain the 16 mm spacing between the discs 44. A device of Constant water level was used to maintain a constant water reservoir level during the test to ensure a constant thermal capacity for the reservoir and conditions of resting state In order to control the humid inlet focus temperature, a recirculation conduit of air 49 was used between the inlet and outlet cross section. The fan outlet, located after the outlet of the air duct, was connected to a flexible duct with a diameter of 152 mm which is connected to the air duct inlet. To control the wet focus, a damper 41 is positioned between the outlet of the air duct and the inlet of the blower 48 to control the amount of fresh air. Since air is added to the system here, a second damper 41 'is added in the middle of the venting duct. Hot water was used to simulate a condensing refrigerant. A constant temperature bath 60 was used to maintain a constant inlet water temperature and was contained in an insulated box with an electrical collector of 1000 W and a temperature control test. A centrifugal pump of 250 W 61 was used to circulate the water through the refrigerant cycle. The speed of the pump varied via a 2.8 kVA auto transformer. The air flow was prohibited by a 12V DC 48 centrifugal blower which was activated by a DC power supply connected in series with a 1.4 kVA auto-transformer, which allows the variable air flow rate. The disks 44 in this parallel flow centrifugation were rotated with a 125 W motor. The arrow of the motor was joined to the arrow of the disk by means of a universal joint which is corrected by any misalignment of the two arrows. The motor is connected to a compatible motor controller, which allowed speed adjustment from 0 rpm to 1800 rpm. The key flow regimes to determine the performance of the condenser are the volume flow rates of air and water. A turbine flow measurement was used to measure the water flow rate. The air flow rate was measured by means of a differential pressure transducer which measures the pressure drop through the flow nozzles via two pressure connections. Depending on the air flow rate, either a tube diameter of 38 mm or a mouthpiece with a tube diameter of 76 mm was used. This pressure drop is subsequently used to calculate the flow rate of air volume.

For all temperature measurements, T-type thermocouplers (copper-constant) were used. The humidity of inlet and outlet air were measured using two humidity / temperature transmitters. A Hewlett-Packard HP3497A data acquisition / control unit was used to measure the voltage outputs of the different measurement devices. The data collected for each test included condenser water inlet and outlet temperatures; air inlet and outlet temperatures; relative humidities of air inlet and outlet; water volume flow rate of the condenser; flow rate of air volume; water tank temperature; temperature of the middle point of the condenser pipe; disc temperature; angular velocity of the disk; and volume of water consumed. Disk angular velocity effect The effect of disk angular velocity on the removal of heat at various air flow rates is shown in Fig. 6. Fig. 6 shows that the heat removal rate increases rapidly from 0 at 15 rpm but becomes almost asymptotic beyond 30 rpm. Figs. 7 and 8 show the effect of the disk's angular velocity on the total and lateral water UA values, respectively. The UA driven by enthalpy shows the same asymptotic tendency as the heat removal regime. Since the enthalpy difference between the inlet air and the inlet water remains absolutely constant for these tests, the UA reflects the heat removal regime. The lateral water UA shows a significant increase while increasing the angular velocity, but the rate of increase decreases as rpm increases. This effect is expected since the water reservoir becomes more turbulent at higher rpm. Also, the air flow regime has no effect on this UA value, as shown in the figure. Effect of the air flow regime Fig. 9 shows the effect of the air flow rate on the capacity of the condenser. As the flow rate increases, the rate of heat removal is consequently increased. The heat removal capabilities increase the higher flow rates and lower the outlet temperature of the condenser water. The water temperature on the discs is limited by the wet focus of the inlet air, and as the condenser outlet temperature decreases, the effective temperature and enthalpy differences decrease. This creates additional, increasingly difficult improvements and can cause the deviation to decrease. Effect of disc material Fig. 10 shows the effect of different disc materials on the heat removal regime. Coroplast ™ material is a double wall, corrugated polypropylene material. Coroplast sheets in 2 mm and 5 mm thickness were used as the disc material. As shown in Fig. 13, the aluminum discs have a higher heat removal rate, but the deviation is not considered statistically significant. The data in Fig. 10 shows that the disc material has only a small effect on the system's heat removal regime. This suggests that the water film is the primary heat carrier. Two calculations verify this. First, the temperature of the disc changes not by more than 0.05 ° C from where it leaves the water tank to the point where it returns to enter, measured by a thermo coupler on the disk. The total heat capacity of the aluminum discs in the apparatus is 2203 J / K. At 30 rpm, the discs make 0.5 revolutions in a second (corresponding to two readings of the thermocouple per revolution), meaning that these can gain or lose their full capacity of heat in two seconds. With a maximum temperature change of 0.05 ° C, this results in 55 W. This is approximately 11% of the heat removal rate at 30 rpm, which agrees with the marginal effects of changes in disc material observed exp enmenia Imente. The second calculation is based on the premise that water must carry heat if the disk does not. A hydrodynamic analysis by Landau and Levich, as described in Probstein (1989), was used to calculate the water film thickness. Analyzes include surface tension, viscosity, and gravity forces to develop the liquid film on a vertical sheet that is extracted from a liquid reservoir. In the apparatus, the discs were wetted from a radius of 50.8 mm to the external radius of 305 mm. The calculations showed that in these places, the thickness value of the film is 0.0368 mm and 0.121 mm, respectively. With an average film thickness of 0.083, the total volume of water on the part of the disk in air is 51.8 x 103 mm3, and the total heat capacity is approximately 216 J / K. If we assume that the water leaves the tank at the tank temperature and enters the tank at the wet bulb temperature of the existing air, the temperature change is approximately 5 ° C. This means that the water film transfers 540 W of heat. This is very close to the actual measured values. It is crucial to observe the considerably large temperature change of the water film compared to the discs. Along with the data, these two analyzes show that the water film, and not the discs, is the main means of heat transfer. Fig. 11 shows a preferred use of the evaporator cooler of the present invention in a refrigeration system in some conventional manner. In Fig. 11, a compressor 50 supplies a refrigerant through line 51 to an evaporator cooler 52 in accordance with the present invention, serving here as a condenser, wherein the refrigerant vapor condenses. By removing the evaporator cooler (condenser) 52, the liquid cooler is fed via line 53 to an evaporator 54 where at least a portion of the refrigerant evaporates whereby it cools a compartment 55 of the evaporator of housing 54. refrigerant vapor is then returned to the compressor 50 through line 56. The invention can be modalized into other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments, therefore, should be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description and therefore, all changes are intended to be that are within the meaning and scale of equivalence of the claims, are covered in it.

Claims (20)

1. CLAIMS 1. An evaporator cooler comprising: a liquid cooler tank with an upper surface of the tank in contact with air; a rotary arrow having a longitudinal axis apprately parallel to the upper surface of the reservoir; means for rotating said arrow; and at least one wheel member mounted and extending radially from said rotary arrow, said wheel member entering the tank, leaving the tank in the air space and exiting the air to re-enter the tank continuously, in one cycle repetitive, as said arrow is rotated, by means of which liquid cooler in the tank adhered to said wheel evaporates into the air upon entering the air, cooling the wheel and the remaining adherent liquid refrigerant, the cooled wheel and the refrigerant adhering liquid remaining by cooling the reservoir upon re-entry.
2. 2. The evaporator cooler of claim 1, further comprising: a fan for blowing an air stream through a portion of said wheel exposed to air.
3. 3. The evaporator cooler of claim 2, further comprising a tank holding said liquid cooler reservoir and defining an air space enclosed before the upper surface of said liquid reservoir through which said air stream is moves by said fan.
4. 4. The evaporator cooler of claim 3, further comprising at least one heat exchange member in contact with said liquid cooler and containing a heat exchange medium for cooling.
5. The evaporator cooler of claim 3, further comprising plural rows of tubes mounted within said tank, posterior to the upper surface of the liquid cooler reservoir, said parallel rows of tubes being separated to define channels therebetween and in where plural wheel members are separated along said rotary arrow in positions corresponding to said channels.
6. 6. The evaporator cooler of claim 5, wherein each of said rows is formed of a single tube bend to provide vertically arranged plural horizontal operations.
7. 7. The evaporator cooler of claim 5, wherein said wheels are circular discs.
8. 8. The evaporator cooler of claim 6, wherein said circular discs are corrugated.
9. 9. The evaporator cooler of claim 1, wherein less than 50% of the surface area of the surface member is immersed in the bath.
10. 10. The evaporator cooler of claim 1, wherein 30-50% of the diameter of the wheel member is immersed in the bath. 1.
11. A refrigeration unit comprising: an evaporator condenser, said evaporator condenser comprising: a liquid cooler reservoir, with an upper surface of the reservoir in contact with air; a rotary arrow having a longitudinal axis apprately parallel to the upper surface of the reservoir; at least one wheel member mounted and extending radially from said rotary arrow partially submerged within the liquid cooler and extending in the air before the liquid cooler for evaporation of the coolant liquid adhering thereof, whereby the cooler The liquid cools as said wheel member re-enters the liquid cooler; a compressor for feeding the refrigerant, at least partially in the vapor state, to said condenser; and an evaporator mounted within a compartment for receiving liquid cooler exiting said condenser and thereby cooling said compartment.
12. 12. The refrigeration unit of claim 1, wherein said evaporator condenser further comprises a fan for blowing a stream of air through the upper surface of the liquid cooler reservoir.
13. 13. The refrigeration unit of claim 12, wherein said evaporator condenser further comprises a tank holding said liquid cooler reservoir and defining an air space enclosed before the upper surface of said liquid reservoir through which said stream of air moves through said fan.
14. The refrigeration unit of claim 13, wherein said evaporator condenser further comprises at least one heat exchange member in contact with said liquid cooler and containing a heat exchange medium for cooling.
15. 15. The refrigeration unit of claim 14, wherein said evaporator condenser further comprises plural rows of tubes mounted within said tank, beyond the upper surface of the liquid cooler reservoir, said parallel rows of tubes being separated for defining channels therebetween and wherein plural wheel members separate along said rotary arrow at positions corresponding to said channels.
16. 16. The refrigeration unit of claim 10, wherein each of said rows is formed of a single tube bend to provide vertically arranged plural horizontal operations.
17. 17. The refrigeration unit of claim 15, wherein said wheels are circular discs.
18. 18. The refrigeration unit of claim 10, wherein said circular discs are corrugated.
19. 19. The evaporator cooler of claim 10, wherein 30-50% of the diameter of the wheel member is. immersed in the bath
20. 20. A method for evaporative cooling a fluid comprising: providing a tank holding a reservoir of the liquid cooler with parallel rows of tubes to pass the fluid that will be cooled through them in a heat exchange relationship with the liquid cooler contained in the tank, and a plurality of partially submerged disks inside the liquid cooler and extending into the air space before the liquid cooler; passing a stream of air over portions of the disks that extend into the air space for the evaporation of liquid cooler from the surfaces of the disks; and continuously rotating the discs such that a portion greater than the surface area of the discs, is alternately submerged in the liquid cooler and exposed to said air stream, thereby evaporating the liquid cooler that adheres to the exposed portions of the discs in contact with said air currents, evaporates from them and the liquid cooler is cooled upon re-entering the portions of surfaces exposed to the liquid cooler reservoir.