Abstract:
Disclosed is a hybrid refrigeration full fresh air-conditioning unit, which achieves multistage cooling by means of the combination of a surface cooler cooling system, a refrigerant air-conditioning system and a direct expansion type air-conditioning system. The unit has an outdoor side mainly for cool water supply to a cooler ( 115 ) and conducting heat dissipation on a condenser ( 212 ) and an indoor side mainly for conducting multistage treatment of air entering a room. The indoor side and the outdoor side are connected to form a whole and are isolated via a panel. The refrigerant air-conditioning system cooperates with one or two of the other systems. Each system can independently operate or simultaneously operate together so that temperature and humidity control for all-weather can be provided, and their operation can be conducted in the most economical and environmental friendly manner under different temperature and humidity condition.

Description:
BACKGROUND OF THE PRESENT INVENTION 
       [0001]    1. Field of Invention 
         [0002]    The present invention relates to air-conditioning, and more particularly to a full fresh air-conditioning unit with hybrid cooling. 
         [0003]    2. Description of Related Arts 
         [0004]    Chlorodifluoromethane (R22) is a type of low temperature refrigerant which can obtain a refrigerant temperature of −80° C. R22 is a colorless and almost odorless gas at room temperature and is non-flammable, non-explosive and non-corrosive. Both the chemical stability and thermos-stability of R22 is very high. Particularly, in the absence of water moisture, no reaction with general metal will occur below 200° C. When water does exist, only reaction with a base will occur slowly. Though cleavage will occur under high temperature, it is still a safe refrigerant. 
         [0005]    Air-conditioning unit refers to a device which utilizes refrigerant such as R22 to produce cold water at 7-12° C. by heat exchange through the work done by a compressor to provide the cold water to the air-conditioned box at the terminal end, and is classified into two main categories, which are air-cooled and water-cooled. 
         [0006]    At present, the air-conditioning device which is used by most users in the market is the air-conditioning unit which employs a compressor and a refrigerant system. The energy efficiency ratio of this type of air-conditioning unit is about 3.0. Since R22 is the most common refrigerant being used, the ozone depletion index is 0.05 and the global warming index is 0.34. 
         [0007]    At present, some types of air-conditioning device which utilize water-cooled arrangement also appear in the market. For example, Chinese patent CN01270637.X disclosed a water-curtain fan air-conditioning device and CN99220698.7 disclosed an energy-saving water-cooled air-conditioning device. The majority of this type of conventional water-cooled air-conditioning are composed of water curtain, fan, water supply system and related parts. This type of water-cooled air-conditioning device has a very small temperature difference between the air inlet and outlet, which is usually only about 5˜8° C., and the outlet humidity is as high as 95% and the output air always carries water droplets. At present, though this type of water-cooled air-conditioning device can achieve the object of energy-saving, the effect is not satisfactory and further researches and improvements are needed. 
       SUMMARY OF THE PRESENT INVENTION 
       [0008]    An object of the present invention is to provide a full fresh air-conditioning unit with hybrid cooling arrangement which is of high efficiency of heat exchange, energy-saving and environmental friendly. 
         [0009]    A full fresh air-conditioning unit with hybrid cooling which comprises a chassis and a refrigerant air-conditioning system provided inside the chassis, the air-conditioning unit further comprising at least one of a surface cooler cooling system and a direct evaporation type air-conditioning system inside the chassis; the chassis comprises a first compartment and a second compartment; the refrigerant air-conditioning system comprises a compressor, a condenser, an expansion valve and an exhaust fan which are positioned inside the first compartment; and an evaporator and a first fan unit which are positioned inside the second compartment; the surface cooler system comprises a first water storage tank, a first pump and a first heat exchanger provided inside the first compartment; and a cooler provided inside the second compartment, wherein the first water storage tank, the first pump, the cooler and the first heat exchanger are connected through a first connecting pipe to form an independent cycling system; the direct evaporation type air-conditioning system comprises a second heat exchanger, a second water storage tank and a second pump provided inside the second compartment; the second water storage tank, the second pump and the second heat exchanger are connected through a second connecting pipe to form an independent cycling system; both the first compartment and the second compartment have fresh air inlets, and the second compartment has an air outlet for the air-conditioning unit, the first compartment has a plurality of air outlets provided at a position opposite to the exhaust fan. 
         [0010]    Preferably, the chassis has a rectangular structure and comprises a partition panel at a middle portion for dividing the chassis into the first compartment and the second compartment while isolating air passage between the first compartment and the second compartment. 
         [0011]    Preferably, the fresh air inlets are provided on two opposing sides of the first compartment which are connected through the partition panel, a netlike panel is provided on the fresh air inlet of the first compartment for each the fresh air inlet; the exhaust fan is positioned at a middle portion of the first compartment, the air outlets are provided at one side of sais first compartment which is opposite to the partition panel. 
         [0012]    Preferably, the fresh air inlet is provided on one side of the second compartment which is connecting to the partition panel, and a rainproof hat is provided at a position outside the fresh air inlet, the air outlet for the air-conditioning unit is provided at another side of the second compartment which is connecting to the partition panel. 
         [0013]    Preferably, the first fan unit is connected to the fresh air inlet of the second compartment through an inlet unit, the evaporator is mounted between an outlet of the first fan unit and the air outlet for the air-conditioning unit; when the air-conditioning unit includes the surface cooler cooling system of the surface cooler cooling system and the direct evaporation type air-conditioning system, the cooler is provided between the outlet of the first fan unit and the evaporator; when the air-conditioning unit includes the direct evaporation type air-conditioning system of the surface cooler cooling system and the direct evaporation type air-conditioning system, the second heat exchanger is positioned close to the air outlet of the air-conditioning unit, the second pump and second water storage tank is positioned close to the second heat exchanger in a bottom portion of the second compartment; the air outlet of the air-conditioning unit has an inner side at which a water shield panel is provided, the water shield panel has a water outlet connecting to the second water storage tank. 
         [0014]    Preferably, the surface cooler cooling system comprises two first heat exchangers which are positioned proximal to the two fresh air inlets of the first compartment respectively and are connected through the first connecting pipe; the first water storage tank is provided at a bottom of the first compartment. 
         [0015]    Preferably, the refrigerant air-conditioning system comprises two inter-connecting condensers which are positioned proximal to the two fresh air inlets of the first compartment respectively. 
         [0016]    Preferably, the unit further comprises an electrical control unit positioned inside the second compartment. 
         [0017]    Preferably, the first fan unit is a centrifugal fan, the evaporator is a fin type evaporator, and the condenser is a fin type condenser. 
         [0018]    Preferably, both the first heat exchanger and the second heat exchanger are heat exchanger with honeycomb-shaped and multi-layered corrugated fiber. 
         [0019]    The advantageous effect of the full fresh air-conditioning unit with hybrid cooling of the present invention includes a conventional refrigerant air-conditioning system, and further includes at least one of the surface cooler cooling system and the direct evaporation type air-conditioning system. Accordingly, at least two air-conditioning systems which can be work together. This at least two systems can be operated independently or together, therefore capable of providing all weather temperature and humidity control which is energy saving and environmental friendly, and providing the most economical and environmental friendly mode of operation under different temperature and humidity conditions. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]      FIG. 1  is a schematic diagram showing the internal structures of a full fresh air-conditioning unit with hybrid cooling according to a preferred embodiment of the present invention. 
           [0021]      FIG. 2  is a perspective view of a full fresh air-conditioning unit with hybrid cooling according to a preferred embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0022]    The present invention is further described in details with the accompanying drawings and embodiments. 
         [0023]    Referring to  FIG. 1  of the drawings, according to a preferred embodiment of the present invention, a full fresh air-conditioning unit with hybrid cooling comprises a chassis  800  which is a generally rectangular box shaped structure; and a refrigerant air-conditioning system, a surface cooler cooling system and a direct evaporation type air-conditioning system inside the chassis  800 . These three systems can operate independently, any two of them can operate together and all three of them can operate at the same time. 
         [0024]    Wherein, the chassis  800  comprises a partition panel  801  at a middle portion to divide the chassis  800  into a first compartment  810  and a second compartment  820 , the partition panel  801  is also used to provide air passage isolation between the first compartment  810  and the second compartment  820 . The partition panel  801  has a plurality of piping holes and wiring holes solely for connecting the corresponding parts between the two compartments. 
         [0025]    The first compartment  810  has two opposing sides which are connected through the partition panel  801  and fresh air inlets are provided on the two sides. The first compartment  810  comprises a netlike panel  210  provided at the fresh air inlet for the two fresh air inlets to filter large granular particles in the air. The first compartment  810  has a circular air outlet provided one side which is opposite to the partition panel  801  and comprises an air outlet panel  217  mounted to the air outlet. The air outlet panel  217  is a sheet metal which has a plurality of large circular holes or rectangular holes. The fresh air from outside enters into the chassis through the netlike panels  210  at two ends of the first compartment and exits from the air outlet panel  217  to outside, therefore the first compartment  810  can also be referred to as an external side compartment. 
         [0026]    The second compartment  820  has one side which is connected to the partition panel  801  and a fresh air inlet is provided thereon and an air inlet panel  111  is mounted onto the fresh air inlet. The second compartment  820  comprises a rainproof hat  110  provided on an external side of the fresh air inlet for preventing rain water from entering into the second compartment  820 . The rainproof hat  110  has an inlet at which a filter mesh can be installed. The air inlet panel  111  is a sheet metal which may include a plurality of large circular holes or rectangular holes. The second compartment  820  has an air outlet  121  for the air-conditioning unit at another side which is connected to the partition panel  801 . The air outlet  121 , through air ducts, transports the air output from the full fresh air-conditioning unit with hybrid cooling of the present invention to a predetermined space. The outside fresh air enters into the chassis through the air inlet panel  111  at one side of the second compartment and exits from the air outlet  121  to an interior area, therefore the second compartment  820  can also be referred to as an internal side compartment. 
         [0027]    The refrigerant air-conditioning system of the present invention is similar to a conventional refrigerant air-conditioning system and mainly comprises a compressor  214 , a condenser  212 , an expansion valve  219 , an exhaust fan  215 , an evaporator  116  and a first fan unit  114 . These parts&#39; structure, connection and working principles are the same as the conventional refrigerant air-conditioning system, and are not repeated here. In particular, the compressor  214 , the condenser  212 , the expansion valve  219  and the exhaust fan  215  are installed inside the first compartment  810 . The evaporator  116  and the first fan unit  114  are installed inside the second compartment  820 . Preferably, the refrigerant employs high efficient environmental friendly refrigerants such as R134a, R407c or R410A. 
         [0028]    The first fan unit  114  employs a centrifugal fan in which its air inlet is connected to the air inlet panel  111  through an inlet  113  and an inlet unit  112 , therefore after the outside fresh air enters into the air inlet panel  111 , all the fresh air will enter into the first fan unit  114 . The full fresh air-conditioning unit with hybrid cooling comprises an electrical control unit  100  near the air inlet panel  111 , and particularly, is at one side of the inlet unit  112 . Preferably, the evaporator  116  is a fin type evaporator and is mounted between the outlet of the first fan unit  114  and the air outlet  121  of the air-conditioning unit such that the air blown from the first fan unit  114  will pass through the evaporator  116  and have changes in temperature. 
         [0029]    Preferably, the condenser  212  is a fin type condenser. According to this embodiment, two inter-connecting condensers  212  are provided near the two netlike panels  210  at two sides of the first compartment  810  respectively. The exhaust fan  215  is installed in the middle portion of the first compartment  810  and its outlet is facing directly to the air outlet panel  217 . The compressor  214  and the expansion valve  219  are provided at two sides of the exhaust fan  215  respectively. The exhaust fan  215  sucks air from the two sides of the first compartment and blow out the air from the air outlet panel  217  in the middle portion, therefore providing heat dissipation effect to each internal parts of the chassis. 
         [0030]    The surface cooler cooling system mainly comprises a first water storage tank  213 , a first pump  218  and a first heat exchanger  211  provided inside the first compartment  810 , and a cooler  115  inside the second compartment  820 . The first water storage tank  213 , the first pump  218 , the cooler  115  and the first heat exchanger  211  are connected through a first connecting pipe  216  to form an independent cycling system. Wherein two first heat exchangers  211  are employed and positioned near to the two netlike panels  210  at two sides of the first compartment respectively, and are connected through the connecting pipe  216 . In particular, the first heat exchanger  211  is installed between the netlike panel  210  and the condenser  212 , while the first heat exchanger  211  employs a heat exchanger with honeycomb-shaped and multi-layered corrugated fiber. The first water storage tank  213  in installed at a bottom portion of the first compartment  810 , and, in this particular embodiment, is installed between the exhaust fan  215 , the compressor  214  and one of the condensers  212 . The cooler  115  is installed inside the second compartment  820  between the outlet of the first fan unit  114  and the evaporator  116 . It is appreciated that the cooler  115  can be installed at any position between the outlet of the first fan unit  114  and the air outlet  121 . 
         [0031]    The work principle of the surface cooler cooling system: the water inside the first water storage tank  213  (the water temperature is lower than room temperature) under the effect of the first pump  218  is supplied to the cooler  115 . At the same time, the outside fresh air under the effect of the first fan unit  114  is forced to flow through and washing the cooler  115  such that the heat in the air is transferred to the water inside the cooler  115 , thereby the air temperature is lowered. The water flow of the cooler  115  absorbs the heat and is guided to flow through the first connecting pipe  216  to the first heat exchanger  211  and then finally flows back to the first water storage tank  213 . Inside the first heat exchanger  211 , the water at high temperature under the effect of the exhaust fan  215  is forced to evaporate and dissipate the heat, thus the water temperature is lowered. Inside the first compartment, a strong convention is formed by the exhaust fan and the two fresh air inlets at two sides of the first compartment, and a great airflow energy is provided. Also, the heat exchangers (the first heat exchanger) at the two sides of the fresh air inlet employ honeycomb-shaped and multi-layered corrugated fiber construction, and a correspondingly, a pump for cooler with a large water supply is also used, therefore, the water evaporation on the parts of the first heat exchanger parts can carry away a great volume of latent heat while dramatically lowered the water temperature of the water flow from the heat exchanger with honeycomb-shaped and multi-layered corrugated fiber, hence cooled water is provided to the cooler. 
         [0032]    The surface cooler cooling system utilized cooled water as the medium to enter into the second compartment for lowering the temperature of the air inside the second compartment, while the source of cooled water of the cooler is the low temperature water formed through evaporation from the exhaust fan in the second compartment and the heat exchanger with honeycomb-shaped and multi-layered corrugated fiber, thus the cooling effect at the first stage cooling is relatively significant and energy saving. When the environmental temperature is relatively high, the refrigerant air-conditioning system and the surface cooler cooling system are operated together to provide a very significant cooling effect and can be operated continuously under the condition of high temperature (temperature of the high temperature air is lowered through the first heat exchanger, then is further lowered by the condenser of the refrigerant air-conditioning system, thus significant cooling effect is provided), which is very difficult to achieve in conventional air-conditioning system. 
         [0033]    The direct evaporation type air-conditioning system mainly comprises a second heat exchanger  119 , a second water storage tank  118  and a second pump  117 . The direct evaporation type air-conditioning system is the only system which has all its parts installed inside the second compartment  820 . The second heat exchanger  119 , the second water storage tank  118  and the second pump  117  are connected through a second connecting pipe to form an independent cycling system. The second heat exchanger  119  employs a heat exchanger with honeycomb-shaped and multi-layered corrugated fiber and is preferably positioned between the evaporator  116  and the air outlet  121 . Since the air output has a relatively high humidity, the second pump  117  and the second water storage tank  118  is provided near the second heat exchanger  119  of the second compartment at a bottom portion. 
         [0034]    The work principle of the direct evaporation type air-conditioning system is that the outside fresh air under the effect of the first fan unit  114  is forced to flow and wash the second heat exchanger  119  such that the heat in the air is transferred to the water inside the second heat exchanger  119 , thereby the air temperature is lowered (the heat is absorbed through water evaporation, and the temperature of both air and water is lowered) The water from the second heat exchanger  119  is supplied through the second pump  117  from the second water storage tank  118 , after flowing through the second heat exchanger  119  to return back to the second water storage tank  118 . The direct evaporation type air-conditioning system utilizes the latent heat of vaporization from water and the proportion of sensible heat is very low. 
         [0035]    Since the air output from the second heat exchanger  119  is relatively great, the air outlet  121  of the air-conditioning unit includes a water shield panel  120  at its inner side so as to prevent water droplets being carried by the airflow. The water shield panel  120  has a water outlet connecting to the second water storage tank  118 . The water shield panel  120  can be manufactured by ABS (Acrylonitrile butadiene styrene) and can retain the relatively great water droplets in the air. 
         [0036]    The present invention mainly makes use of a free combination of the surface cooler cooling system, the high efficiency and environmental friendly refrigerant air-conditioning system, and the direct evaporation type air-conditioning system (air-conditioning system equipped with heat exchanger with honeycomb-shaped and multi-layered corrugated fiber) to realize a multi-stage cooling. In particular, the side of the first compartment (exterior side) is mainly function to provide cooled water to the cooler and provide heat dissipation for the compressor condenser, while the side of the second compartment (inner side) is mainly function to process multi-stage treatment of air entering to the internal space. The inner side and the exterior side are connected to form an integral structure and is divided by a partition panel. 
         [0037]    When all the three air-conditioning system are operated at the same time, after the outside fresh air is passing through the exhaust fan  215 , the air flows through the corresponding netlike panel  210  to the first heat exchanger. The relative pressure of the air at the position of the first heat exchanger  211  is a negative pressure. The hot water flowing from the outlet of the cooler  115  is pouring down through the first heat exchanger. When sufficient contact is made between the water droplets and air, evaporation will occur under the effect of pressure because there is the pressure difference between the air and water vapor, then the heat from the water is removed and the water temperature is lowered. The cooled water flows to the first water storage tank  213 , through the first pump  218  to provide water supply to the cooler  115 . The cooler  115  further has heat exchange with the air entering in the inlet unit  112  (first stage cooling). Under the effect of the first fan unit  114 , the fresh air with lowered loading will have heat exchange with the fin-type evaporator  116  again such that the temperature and humidity will decrease at the same time (second stage cooling and de-humidification). Finally, when passing through the second heat exchanger  119 , the air with low temperature and low enthalpy will undergo a third stage cooling and humidity adjustment. The recycling water in the second heat exchange  119  is under the ambient condition of lowered temperature and humidity, the water temperature is between the dry bulb temperature and the wet bulb temperature of the cooled air from the evaporator, the water absorbs heat and evaporates, thus the air temperature is lowered again (third stage cooling and humidifying) while the relative humidity of the air is increased. In order to prevent the air from the second heat exchanger  119  to carry water droplets to inside, the water shield panel  120  is provided between the second heat exchanger  119  and the air outlet  121 . Accordingly, after the outside fresh air is flowing from the inner side by the centrifugal fan  114  to the cooler  115 , the evaporator  116 , the second heat exchanger  119  for cooling, then enter inside from the air outlet at the inner side through the water shield panel  120 . 
         [0038]    According to the present invention, after the outside air passes through the cooler, the fin-type evaporator and the heat exchanger with honeycomb-shaped and multi-layered corrugated fiber in the second compartment (the second heat exchanger) for first-, second- and third-stage treatment, the temperature difference in the outlet of the second compartment can reach 8˜20° C. Under different environmental conditions, switching to different operation mode can achieve the maximum power saving and cooling effect. 
         [0039]    In other embodiments, based on the actual requirements, the full fresh air-conditioning unit with hybrid cooling of the present invention can include only the refrigerant air-conditioning system and the surface cooler cooling system, or only the refrigerant air-conditioning system and the direct evaporation type air-conditioning system. 
         [0040]    One skilled in the art will understand that the embodiment of the present invention as shown in the drawings and described above is exemplary only and not intended to be limiting. It will thus be seen that the objects of the present invention have been fully and effectively accomplished. It embodiments have been shown and described for the purposes of illustrating the functional and structural principles of the present invention and is subject to change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.