Patent Application
20230031717
The present application relates to the field of radiation heat exchange, and more particularly to a radiation heat exchange device.
The heat pump system in prior ceiling air conditioning system is not designed to make directly radiation heat-exchanging ceiling cool, but cold water from water-circulation system is used to make it cool. If the heat pump system is used to make it cool directly, the bottom surface of radiation heat-exchanging ceiling will dew heavily due to the lower temperature, and when the dew condenses to a certain extent it will drop from the ceiling and thus form so-called “artificial rain” in room. The prior ceiling conditioning system with water circulation system can be used in the relatively dry areas such as Northern Europe because the humidity of these areas is relatively low and radiation heat-exchanging ceiling will not dew even if at a relatively lower temperature.
However, there exists serious dewing problem when prior ceiling air conditioning system is used in relatively more humid areas such as Southern China or Southeast Asia. Heavy dewing occurred in the prior ceiling air conditioning systems installed in Macau, Shenzhen, etc., which resulted in frequent “artificial rain” from a room ceiling. For the prior air conditioning systems with dew point sensor they would automatically stop working frequently because the sensor detected heavy dewing.
After a long-term observation and study, the inventor of the present application found out that the main reasons why the prior radiation heat-exchanging ceiling are easy to dew in more humid environments are as follows:
1. The humidity in moist areas is about 70-80%, and the vapor content in the air is close to saturation. Its dew point temperature is only few lower than the ambient temperature. Therefore it is easy for vapor to contact objects of which their temperature is lower than the dew point and thus dew will form on these objects.
2. The prior radiation heat-exchanging ceiling includes metal ceiling plate and heat-exchanging coil. The heat-exchanging coil is installed into the grooves on top of the metal ceiling plate and contacts with the metal ceiling plate directly. Therefore the temperature on the area in which the heat-exchanging coil contacts with the metal ceiling is often lower than the dew point temperature.
In hot and moist areas the circulating water of a ceiling conditioning system would be set at a temperature as low as possible for effective cooling. Because its heat-exchanging coil contacts directly with its metal ceiling plate the circulating water at low temperature will readily make the temperature at the contacting area of the bottom surface of the metal ceiling plate lower than the dew point temperature. And this will inevitably cause dewing problems.
Therefore, it is necessary to provide a direct-cooling air conditioning system in which a radiation heat-exchanging ceiling is installed to avoid dewing.
Generally, there are serval types of metal radiation heat exchange plate as follows:
The heat exchange copper tube and the metal radiant heat transfer plate are in direct contact, while the heat exchange copper tube and the metal heat radiant plate are connected by heat conduction. This type is mostly used in air-conditioning systems. In Northern European countries, cold water at 12° C. is configured to run along the heat exchange copper tube, while the surface temperature of the metal radiant heat transfer plate is 20° C. Since the surface of the metal radiant heat transfer plate has a cold line at 14° C., it is still possible to function in most of the time in Northern European countries. However, in a relatively hot and humid environment, the cold line at 14° C. is already lower than the dew point temperature, such that the metal radiant heat transfer plate will be condensed. In order to avoid condensation, cold water at 16° C. is used, wherein the temperature of the contact portion between the metal radiant heat transfer plate and the heat exchange copper tube is only 18° C., while the temperature of the non-contact portion of the surface of the metal radiant heat transfer plate will increase to 24° C. The cooling capacity of the metal radiant heat transfer plate is extremely low, such that when this type is used in air conditioning systems in huge heat and high humidity areas, this high-temperature water metal radiant heat transfer plate can only be used as a supplement to ordinary air conditioning systems.
For other improved metal radiant heat transfer structures, in order to solve the cold uniformity of the metal radiant heat transfer plate surface, TROX is configured to press against the heat exchange copper tube into a groove-shaped metal base, and then to glue the metal base to the metal radiant heat transfer plate via thermal conductive adhesive. However, under the heating conditions, the thermal conductive adhesive will not only lose its viscosity after heating process but also lose its heat conductivity. Therefore, the TROX's manual specifically states that it “cannot supply heat”.
For other improved structures, the heat exchange copper tube is embedded into the graphite material, and then the graphite block is fixed on the metal radiant heat transfer plate via thermal conductive adhesive. However, when all of the metal radiant heat transfer plates are under refrigeration conditions, the temperature of the heat exchange refrigerant cannot be lower than the air dew point temperature due to surface condensation.
Low temperature radiant panel condensation: Because the intensity of radiative heat exchange is related to the difference of the 4th power of absolute temperature of two surfaces, in order to improve the heat absorption capacity of radiant panel, it is necessary to reduce the surface temperature of radiant panel. However, there is a serious condensation problem when using low-temperature water radiant panels in hot and humid areas.
Cold radiant panel heat has low heat absorption capacity: the cold water temperature of common air conditioner is 7° C. Due to the condensation of low-temperature radiant panel, the current radiant panels on the market use cold water with a temperature higher than the dew point of the air, and general water temperature is 16° C. The water temperature has increased, the average temperature of the radiant panel has increased, and the ability of the radiant panel to absorb heat is very low. Other systems cannot solve the problem of environmental comfort by relying on the radiant panel alone, and still mainly rely on ordinary air conditioners to supply air to the room to meet the the need for comfort.
However, when the existing ceiling air-conditioning system is used in relatively humid regions such as South China or Southeast Asia, there is a serious dew condensation problem. The ceiling air-conditioning system installed in Macau, Shenzhen and other places before has serious condensation, resulting in frequent “artificial rain” on the ceiling of the room. For existing air conditioning systems with dew point sensors, they will often automatically stop working due to the sensor detecting large amounts of dew.
It is found that the main reason that original radiant heat exchange ceiling produces condensation in conventional air-conditioning environment (25° C. of air temperature, 16.7° C. of relative humidity 60% air dew point temperature) is as follows:
The heat transfer copper tube of a conventional radiant panel and the metal ceiling are in contact with heat conduction. If the copper tube passes cold water of 12° C., the average temperature of the board surface is about 20° C., and the indoor is a basically comfortable environment. But at this time, a cold line of about 14° C. appeared where the copper pipe touched the ceiling. Obviously, the temperature of the cold wire is lower than the dew point temperature of standard air, which is 16.7° C., and the cold wire will condense and drip.
In order to avoid dew condensation, the water temperature is raised to 16° C. and the cold line temperature 18° C., then the radiant panel has avoided dew condensation and dripping. However, the temperature of the panel surface has risen to 23° C., and there is no cold radiation intensity in the room, which cannot meet the requirements of comfort, and a large number of conventional air conditioners are required to supply air.
The reason for the dew condensation of the conventional radiant panel is that the heat transfer tube and the surface of the radiant plate adopt contact heat conduction. The contact surface forms a heat transfer low temperature line, and it is the low temperature line that causes condensation. Currently, the condensation problem is solved by increasing the water temperature, but the increase of the water temperature caused the radiant panel's ability to absorb heat to drop sharply.
The technical measure that improves the water inlet temperature of radiant panel to solve condensation is negative, and it is an object of the present invention to adopt the method of eliminating low temperature cold line of radiant panel to solve dew condensation.
These improvements still can only use high-temperature water for cooling.
Therefore, it is necessary to study a radiant panel that uses a low-temperature cold source, has a uniformly adjustable surface temperature, and has strong radiation heat absorption and heat dissipation capabilities, which can meet the comfort requirements by relying on radiation heat transfer.
The purpose of the present invention is to provide a direct-cooling air conditioning system or so-called ceiling conditioning system which employs a radiation heat-exchanging ceiling plate difficult to dew and which can overcome heavy dewing problems occurred on both prior radiation heat-exchanging ceiling and prior ceiling conditioning system.
As one aspect, the present invention is to provide a direct-cooling air conditioning system which includes a heat pump system and a water circulation system wherein the water circulation system includes a water circulation loop which further includes a circulating pump, an air heat-exchanging device and a water heat-exchanging device. The air heat-exchanging device exchanges heat with outside air and the water heat-exchanging device exchanges heat with the heat pump system. In the direct-cooling air conditioning system according to the present invention, the water circulation system includes a plurality of radiation heat-exchanging ceiling plates which comprise metal ceiling plates and heat-exchanging coils. The heat-exchanging coils are fixed on the top of the metal ceiling plates in such a way that the heat-exchanging coils are adjacent to but do not contact with the metal ceiling plates, and there is a layer of thermal insulation material on the top of the heat-exchanging coils. The heat-exchanging coils are connected to the circulation loop of the water circulation system.
In the above direct-cooling air conditioning system because the heat-exchanging coils do not directly contact with the metal ceiling plates there is not any area on the metal ceiling plates with its temperature being lower than the dew point temperature. And thus it is difficult to dew on such an air conditioning system.
In addition, in the above direct-cooling air conditioning system the radiation heat-exchanging ceiling plates in a same room can be connected with each other in series or in parallel or in a combination of both in series and in parallel.
Preferably, in the direct-cooling air conditioning system one or more layers of metal foil can be further placed on the bottom of the thermal insulation material. That is, the metal foil can be placed between the heat-exchanging coils and the layer of thermal insulation material. In such a design the metal foil increases the heat-exchanging area for the heat-exchanging coils and thus improves heat-exchanging efficiency.
As a specific embodiment of the present invention, in the above direct-cooling air conditioning system coil brackets for supporting the heat-exchanging coils can be installed on the top surface of the metal ceiling plates wherein the coil brackets can be made from poor thermal conducting material such as plastics. The heat-exchanging coils can be mounted on the coil brackets. In such a design a correct positioning between the heat-exchanging coils and the metal ceiling plates can be so maintained that they neither contact each other nor be in an excessive distance.
As another specific embodiment of the present invention, in the above direct-cooling air conditioning system a sealing layer can be further placed on the top of the layer of thermal insulation material. The sealing layer covers over the layer of thermal insulation material so as to isolate it from the outside air. In such a design the outside air is prevented from entering into the layer of thermal insulation material, and therefore the heat-exchanging coils will not dew. The thermal insulation material can be kept dry to reach a better insulation effect.
As still another specific embodiment of the present invention, in the above direct-cooling air conditioning system an aluminum foil can be used as the metal foil and glass wool or mineral wool can be used as the thermal insulation material. The aluminum foil, the glass wool and the sealing layer can be stacked up or laminated to form a layer of aluminum foil/glass wool insulation material. In such a design the aluminum foil/glas s wool insulation materials can be available from the market and it can be easily and conveniently closed over the heat-exchanging coils when assembling.
As yet another specific embodiment of the present invention, the above direct-cooling air conditioning system further includes a fresh flue (i.e. a passage for fresh air) with which a fan is equipped. The inlet of the fresh flue is in communication with the outdoor air, and its outlet is in communication with the indoor air. A heat-exchanging coil for fresh air is mounted within the fresh flue, which is connected between the circulating pump of the water circulation system and the heat-exchanging coils of the radiation heat-exchanging ceiling plates. In such a design, the fresh flue can provide dry and cold fresh air when the system is refrigerating, which will not only reduce the duty load of the radiation heat-exchanging ceiling but also prevent the temperature of the circulating water from being lower than the dew point temperature through preheating by the fresh air before entering into the heat-exchanging coils of the radiation heat-exchanging ceiling plates. Therefore dewing will be avoided.
As another specific embodiment of the direct-cooling air conditioning system of the present invention the water circulation loop further includes a water tank for thermal buffering which is positioned between the circulation pump and the heat-exchanging coil for fresh air. In such a design circulating water has a small fluctuation on its temperature and the compressor need not to turn on and off frequently.
As another specific embodiment of the direct-cooling air conditioning system of the present invention, the fresh flue is equipped with a solenoid valve. A solenoid valve is also placed between the circulating pump of the water circulation loop and the heat-exchanging coils of the radiation heat-exchanging ceiling. Such a design has the advantages of being easily adjusted and suitable for central air conditioning.
As another aspect the present invention is to provide a radiation heat-exchanging ceiling plate used in an air-conditioning system, particularly in a direct-cooling air conditioning system such as a ceiling conditioning system. The radiation heat-exchanging ceiling plate includes a metal ceiling plate and a heat-exchanging coil. The heat-exchanging coil is fixed on the top of the metal ceiling plate in such a way that the heat-exchanging coil is adjacent to but does not contact with the metal ceiling plate, and there is a layer of thermal insulation material on the top of the heat-exchanging coil.
Preferably in the above radiation heat-exchanging ceiling plate a layers of metal foil can be further placed on the bottom of the thermal insulation material. That is, the metal foil can be placed between the heat-exchanging coil and the layer of thermal insulation material.
Preferably in the above radiation heat-exchanging ceiling plate coil brackets for supporting the heat-exchanging coil can be installed on the top surface of the metal ceiling plate wherein the coil brackets can be made from poor thermal conducting material such as plastics. In such a design a correct positioning between the heat-exchanging coil and the metal ceiling plate can be so maintained that they neither contact each other nor be in an excessive distance.
Preferably in the above radiation heat-exchanging ceiling plate a sealing layer can be further placed on the top of the layer of thermal insulation material. The sealing layer covers over the layer of thermal insulation material so as to isolate it from the outside air.
Preferably in the above radiation heat-exchanging ceiling plate an aluminum foil can be used as the metal foil and glass wool or mineral wool can be used as the thermal insulation material. The aluminum foil, the glass wool and the sealing layer can be stacked up or laminated to form a layer of aluminum foil/glass wool insulation material.
The direct-cooling air conditioning system of the present invention (i.e. the ceiling conditioning system with radiation heat-exchanging ceiling) is not easy to dew when operation. It belongs to a real quite air conditioning system without any noise because both its compressor and pumps can be placed outside and there is no fan inside. Due to large heat-exchanging area of the ceiling conditioning system the inlet temperature of the coolant can be 5° C. higher than that of an ordinary air conditioning system, and the indoor temperature can be 3° C. higher than that of an ordinary air conditioning system with same comfort level. Therefore compared with a prior air conditioning system the direct-cooling air conditioning system of the present invention has a higher energy efficiency and will save energy in about more than 30%. Thus the direct-cooling air conditioning system of the present invention has a good prospect in the market.
The direct-cooling air conditioning system of the present invention (i.e. the ceiling conditioning system with radiation heat-exchanging ceiling) and the radiation heat-exchanging ceiling plate thereof will be further understood through the following illustrative and non-limitative description of preferred embodiments with reference to the appended drawings.
In order to solve the above-mentioned technical problems, the present invention further provides a radiation heat exchange device with a sub-near-field gap for generating cooling or heating functions. Particularly, the radiation heat exchange device can be refrigerated in a humid and hot environment without condensation, and has a high cooling capacity.
As one aspect, the present invention provides a radiation heat exchange device which comprises a first metal radiant plate and a second metal radiant plate spaced apart from each other. The first metal radiant plate has a first radiant heat exchange zone defined at a plate surface thereof that faces toward the second material radiant plate. The second metal radiant plate is set corresponding to the first radiant heat exchange zone of the first metal radiant plate, wherein a sub-near field gap is defined between the first metal radiant plate and the second metal radiant plate. The minimum distance between the second metal radiant plate and the first radiant heat exchange zone is 2 mm. Accordingly, the first radiant heat exchange zone of the first metal radiant plate and the second metal radiant plate are configured for radiant heat exchange. Particularly, the first metal radiant plate is arranged for exchanging heat with the environment to be temperature-regulated on an opposed plate surface thereof which is far from the second metal radiant plate. The second metal radiant plate is arranged for exchanging heat with cooling and/or heating system on a plate surface of the second metal radiant plate which is away from the first metal radiant plate.
The second metal radiant plate is parallel to the first metal radiant plate. The radiation heat exchange device further comprises an isolation element disposed between the first metal radiant plate and the second metal radiant plate at the first radiant heat exchange zone. The isolation element is arranged for providing a supporting function, wherein the mesh structure of the isolation element is arranged to provide spaces for radiation heat exchange. The isolation element is made of low thermal conductive material. The thickness of the isolation element is 1-3 mm, such that the minimum distance between the second metal radiant plate and the first radiation heat exchange zone of the first metal radiant plate is 1-3 mm.
The thickness of the isolation element is 2 mm, such that the minimum distance between the second metal radiant plate and the first radiation heat exchange zone of the first metal radiant plate is 2 mm.
The radiation heat exchange device further comprises a heat exchanging channel and a heat exchange medium disposed in the heat exchanging channel. The second metal radiant plate is contacted with the heat exchanging channel to form a heat exchange core plate assembly. Accordingly, the second metal radiant plate and the heat exchanging channel are arranged for heat conduction and heat exchange in order to heat exchange with the cooling and/or heating system via the heat exchange medium.
The radiation heat exchange device further comprises two heat radiation enhancing coatings respectively provided on the plate surface of the first metal radiant plate and the plate surface of the second metal radiant plate which are facing toward each other.
The heat exchanging channel is configured as a heat exchanging coil. The second metal radiant plate has a first indentation groove formed thereon by pressing a portion of second metal radiant plate at the plate surface thereof, wherein the heat exchanging channel is disposed at the first indentation groove in order to closely contact an outer wall of the heat exchanging channel with an inner wall of the first indentation groove.
The radiation heat exchange device further comprises at least one coil bracket having a second indention groove, wherein the coil bracket is coupled on the second metal radiant plate at a position that the second indention groove is aligned with and extended along with the first indention groove to form an accommodating channel to receive and retain the heat exchanging channel. The coil bracket is arranged to ensure the close contact between the heat exchanging channel and the second metal radiant plate so as to ensure the heat exchanging channel and the second metal radiant plate being thermally conducted with each other.
The radiation heat exchange device further comprises a thermal insulation element, wherein the second metal radiant plate and the first radiation heat exchange zone of the first metal radiant plate are enclosed by the thermal insulation element for preventing any heat loss therefrom. Particularly, the thermal insulation element is mounted on the first metal radiant plate to form a thermal-insulated sealing cavity therebetween for preventing water vapor from entering into a space between the second metal radiant plate and the first metal radiant plate to form internal dew condensation.
The radiation heat exchange device further comprises an outer casing mounted on the first metal radiant plate to enclose the thermal insulation element for forming the thermal-insulated sealing cavity. The outer casing is configured to protect the thermal insulation element from being damaged by any external force, and to reflect any external thermal radiation energy by an outer reflective surface of the outer casing. The thermal insulation element is configured to isolate the heat transfer between the outer casing and the second metal radiant plate.
Two opening ends of the heat exchanging channel are configured to pass through the thermal insulation element and to extend out of the outer casing. The outer casing has two through slots formed thereat for the two opening ends of the heat exchanging channel being extended out of the outer casing through the through slots respectively. The outer casing further comprises two sealing rings mounted at the through slots and sleeved on the heat exchanging channel for sealing the heat exchanging channel around the through slots where the heat exchanging channel is extended out of the outer casing.
The present invention provides the following advantages: The radiation heat exchange device with a sub-near-field gap is able for providing cooling and heating operations. Particularly, the radiation heat exchange device can be refrigerated in a humid and hot environment without condensation, and has a high cooling capacity. By configuring a minimum distance of 1-3 mm between the first metal radiant plate and the second metal radiant plate, the sub-near field gap for thermal radiation is formed. Through this preset distance, the two metal radiant plates will not be too close to each other so as to prevent any formation of obvious cold temperature and to prevent any condensation during cooling. The sub-near field gap also greatly improves the radiative heat exchange efficiency between the first metal radiant plate and the second metal radiant plate at the heat transfer coil, not only to enhance the heat radiation uniformity of the two plates, but also to improve the temperature uniformity of the outer surface of the first metal radiant plate (the plate surface that is in contact with the environment to be regulated), so as to further prevent any formation of obvious cold temperature lines during cooling. Since there is no information of the cold temperature line, a lower temperature heat exchange medium can also be used for cooling to prevent any condensation. The heat radiation enhancing coatings are coated on the plate surface of the first metal radiant plate and the plate surface of the second metal radiant plate which are facing toward each other to further improve the radiation heat exchange efficiency between the first metal radiant plate and the second metal radiant plate and to enhance the temperature uniformity of the plate surfaces of the metal radiant plates. By wrapping the heat exchanging channel between the coil bracket and the second metal radiant plate, the coil bracket ensures the close contact between the heat exchanging channel and the second metal radiant plate so as to ensure the heat exchanging channel and the second metal radiant plate being thermally conducted with each other. The thermal insulation element is arranged to thermally seal the second metal radiant plate and the first radiation heat exchange zone of the first metal radiant plate for preventing water vapor from entering into a space between the second metal radiant plate and the first metal radiant plate to form internal dew condensation. The outer casing is arranged to enclose the thermal insulation element to protect the thermal insulation element from being damaged by any external force, and to reflect any external thermal radiation energy by an outer reflective surface of the outer casing. The radiation heat exchange device can be used as a heat exchange unit for indoor or outdoor temperature regulation in residential buildings and public buildings. Specifically, the radiation heat exchange device can be configured as wall panels, ceilings, floor panels and the like. The radiation heat exchange device can also be configured as a heat sink for electronic systems, such as communication base stations, server equipment, computer and the like. It is appreciated that the radiation heat exchange device of the present invention can also be used in other relatively low temperature heat exchange conditions.
The numerals in the drawing represent respectively: 1 metal ceiling plate, 2 heat-exchanging coil, 3 glass wool layer, 4 coil brackets, 5 aluminum foil, 6 sealing layer, 7 heat pump system, 8 water-circulation system, 9 pump, 10 air heat-exchanging device, 11 water heat-exchanging device, 12 fresh flue, 13 fan, 14 inlet, 15 outlet, 16 heat-exchanging coil for fresh air, 17 heat pump, 18 throttling elements (such as capillary or expansion valve), 19 sealing strips, and 20 a plurality of radiation heat-exchanging ceiling plates in each room.
One of embodiments of the radiation heat-exchanging ceiling plate of the present invention is shown in
Preferably, the coil bracket 4 connects the heat-exchanging coil 2 to the metal ceiling plate 1 without directly contact with the metal ceiling plate 1. The coil bracket 4 has a low thermal conductivity so that the heat-exchanging coil 2 is maintained at a preset distance from the metal ceiling plate 1 and a gap is formed between the heat-exchanging coil 2 and the metal ceiling plate 1. In particular, the coil bracket 4 has a high strength and small heat transfer coefficient, generally around 0.2-0.3 W/(m·K). A layer of aluminum foil 5 locates under the layer of glass wool 3. The aluminum foil 5 is positioned between the heat-exchanging coil 2 and the layer of glass wool 3. There is also a sealing layer 6 on the top of the layer of glass wool 3. The sealing layer 6 covers on the layer of glass wool 3 so as to isolate it from the outside air. The aluminum foil 5 can also be replaced by a copper foil, and the layer of glass wool 3 can be replaced by another insulation material. In other words, the glass wool 3 serves as a thermal insulation material for heat insulation. The heat-exchanging coil 2 is heat conduction insulated from the top to the bottom between the coil brackets 4 and the thermal insulation material 3. Then, the sealing layer 6 and the metal ceiling plate 1 forms an isolated sealing cavity, and any water or moisture exposure to the heat exchanging coil 2 can be shield by the sealing layer 6 and the metal ceiling plate 1. On the one hand, the direct heat transfer between the heat-exchanging coil and the metal ceiling plate through direct contact is eliminated, and the hot and cold spots in the metal ceiling plate is eliminated. On the other hand, the air or moisture is blocked by the metal ceiling plate 1 and the sealing layer 6. In the absence of hot and cold spots and in the absence of air or moisture, dew cannot be formed. Therefore, the problem of dewing, even in humid environment, can be effectively solved.
It is worth mentioning that since any direct contact or direct heat conduction between the heat-exchanging coil 2 and the metal ceiling plate 1 is eliminated, the gap between the bottom of the heat-exchanging coil 2 and the top of the ceiling plate 1 can allow effective heat exchange by radiation without creating any hot or cold spots. Preferably, the gap between the heat-exchanging coil 2 and the metal ceiling plate 1 is 1.8 mm to 2 mm.
Preferably, two layers of additional radiation-enhancing coating are provided for the metal ceiling plate 1 and the heat-exchanging coil 2 respectively to enhance radiation heat exchange.
As shown in
As shown in
The radiation heat-exchanging ceiling plate as a whole is an integral unit and is arranged to install to a building structure.
For example, the radiation heat-exchanging ceiling plate can be installed on a false ceiling F of a building structure X. The radiation heat-exchanging ceiling plate can simply position onto the rectangular frame of the false ceiling through fitting the bottom side to the false ceiling.
In particular, as shown in
It is worth mentioning that the radiation heat-exchanging ceiling plate is an enclosed structure with two ends of the heat-exchanging coil 2 extending outward. The radiation heat-exchanging ceiling plate can be installed to the false ceiling of the building structure easily through mounting means for the whole radiation heat-exchanging ceiling plate and is not a fixture of the building structure.
It is worth mentioning that the water temperature used in the heat-exchanging coil 4 can achieve 7/12° C., which cannot be reached by other conventional radiant panels which used water with water temperature of 16/19° C.
One of embodiments of the direct-cooling air conditioning system of the present invention is shown in
The above direct-cooling air conditioning system can further comprise a fresh flue 12 which is equipped with a fan 13. The inlet 14 of the fresh flue 12 is in communication with the outdoor air, and its outlet 15 is in communication with the indoor air. A heat-exchanging coil 16 for fresh air is placed within the fresh flue 12, and it is connected between the pump 9 and the heat-exchanging coils 2 of the radiation heat-exchanging ceiling plates. The water heat-exchanging device 11 can be a water tank for thermal buffering which is positioned between the pump 9 and the heat-exchanging coil 16 for fresh air. The evaporator coils of the heat pump system 7 are installed in the water tank for thermal buffering.
A solenoid valve can be equipped in the fresh flue 12, and a solenoid valve can also be placed between the pump 9 of the water circulation loop and the heat-exchanging coils 2 of the radiation heat-exchanging ceiling plates (not shown in the figures).
As another embodiment of the direct-cooling air conditioning system of the present invention the water circulation loop can have an additional water tank for thermal buffering.
Referring to
Particularly, the first metal radiant plate 100 has a first plate surface for communicating with the environment to be temperature-regulated and an opposed second plate surface facing toward the second metal radiant plate 400, wherein the first radiant heat exchange zone is defined at the second plate surface of the first metal radiant plate 100. Likewise, the second metal radiant plate 400 has a first plate surface facing toward the second plate surface of the first metal radiant plate 100 and an opposed second plate surface facing opposite to the first metal radiant plate 100. The sub-near field gap 102 is defined between the second plate surface of the first metal radiant plate 100 and the first plate surface of the second metal radiant plate 400.
According to the second embodiment, the second metal radiant plate 400 is parallel to the first metal radiant plate 100, wherein the first radiant heat exchange zone is located between the first metal radiant plate 100 and the second metal radiant plate 400 and is far away from the second metal radiant plate 400. The radiation heat exchange device according to the second embodiment further comprises an isolation element 300 disposed between the first metal radiant plate 100 and the second metal radiant plate 400, wherein the isolation element 300 is disposed at the first radiation heat exchange zone of the first metal radiant plate 100. In other words, the sub-near field gap 102 is defined as an interval between the first metal radiant plate 100 and the second metal radiant plate 400. It is worth mentioning that the dimensional size of the isolation element 300 must be equal or larger than the dimensional size of the second radiant plate 400. Preferably, the sub-near field gap 102 is formed by the isolation element 300 disposed between the second metal radiant plate 400 and the first metal radiant plate 100 at the first radiation heat exchange zone. Preferably, the isolation element 300 is an isolation net having a mesh structure according to the second embodiment. The isolation element 300 is made of low thermal conductive material. The isolation element 300 is arranged for providing a supporting function, wherein the mesh structure of the isolation element 300 is arranged to provide spaces for radiation heat exchange. Depending on the thickness of the isolation element 300, the width of the sub-near field gap 102 is selectively adjusted. The thickness of the isolation element 300 is 2 mm, such that the minimum distance between the second metal radiant plate 400 and the first metal radiant plate 100 at the first radiation heat exchange zone is 2 mm.
According to the second embodiment, the isolation element 300, which is embodied as a layer of isolation net, is mounted and overlapped on the second plate surface of the first metal radiant plate 100 at the first radiant heat exchange zone thereof. The first plate surface of the second radiant plate 400 is spaced apart from the isolation element 300.
According to the second embodiment, the radiation heat exchange device further comprises a heat exchanging channel 500 and a heat exchange medium 502 disposed in the heat exchanging channel 500. The second metal radiant plate 400 is thermally contacted with the heat exchanging channel 500 to form a heat exchange core plate assembly. Accordingly, the second metal radiant plate 400 and the heat exchanging channel 500 are arranged for heat conduction and heat exchange in order to heat exchange with the cooling and/or heating system via the heat exchange medium 502.
According to the second embodiment, the radiation heat exchange device further comprises at least one heat radiation enhancing coating 200. In the second embodiment, two heat radiation enhancing coatings 200 are respectively provided on the plate surface of the first metal radiant plate 100 and the plate surface of the second metal radiant plate 400 which are facing toward each other. Particularly, one of the heat radiation enhancing coatings 200 is coated on a plate surface of the heat exchange core plate assembly while another heat radiation enhancing coating 200 is coated at the first radiation heat exchange zone of the first metal radiant plate 100. The heat radiation enhancing coatings 200 are arranged to further increase the efficiency of radiant heat exchange between the heat exchange core plate assembly and the first radiation heat exchange zone.
Particularly, one of the heat radiation enhancing coatings 200, as the first radiation enhancing coating, is coated on the second plate surface of the first metal radiant plate 100 at a position that the heat radiation enhancing coating 200 is sandwiched between the second plate surface of the first metal radiant plate 100 and the isolation element 300. The second radiation enhancing coating 200 is coated on the first plate surface of the second metal radiant plate 400.
According to the radiation heat exchange device of the second embodiment, the heat exchanging channel 500 is configured as a heat exchanging coil in the first embodiment. The second metal radiant plate 400 has a first indentation groove formed thereon by pressing a portion of second metal radiant plate 400 at the plate surface thereof, wherein the heat exchanging channel 500 is disposed at the first indentation groove in order to closely contact an outer wall of the heat exchanging channel 500 with an inner wall of the first indentation groove. The radiation heat exchange device further comprises at least one coil bracket 800 having a second indention groove, wherein the coil bracket 800 is coupled on the second plate surface of the second metal radiant plate 400 at a position that the second indention groove is aligned with and extended along with the first indention groove to form an accommodating channel to receive and retain the heat exchanging channel 500. Accordingly, a portion of the outer wall of the heat exchanging channel 500 is closely contacted with an inner wall of the second indention groove of the coil bracket 800 while an opposed portion of the outer wall of the heat exchanging channel 500 is closely contacted with the inner wall of the first indentation groove of the second metal radiant plate 400. The coil bracket 800 is arranged to ensure the close contact between the heat exchanging channel 500 and the second metal radiant plate 400 so as to ensure the heat exchanging channel 500 and the second metal radiant plate 400 being thermally conducted with each other. Preferably, the coil bracket 800 is an elongated arc-shaped strip made of high thermal conductive material. Therefore, the coil bracket 800 not only retains the heat exchanging channel 500 on the second metal radiant plate 400 but also thermal conducts with both the heat exchanging channel 500 and the second metal radiant plate 400. The difference between the coil bracket in the first embodiment and the coil bracket 800 in the second embodiment is that the coil bracket 800 in the second embodiment is made of high thermal conductive material. It is worth mentioning that the first indentation groove of the second metal radiant plate 400 is tangentially contacted with the isolation element 300 to thermally conduct the second metal radiant plate 400 with the first metal radiant plate 100 through the mesh structure of the isolation element 300.
In other words, the minimum distance between the second metal radiant plate 400 and the first metal radiant plate 100 is defined at a distance between the tangential point of the first indentation groove of the second metal radiant plate 400 and the first metal radiant plate 100. The tangential point of the first indentation groove of the second metal radiant plate 400 is the point being tangentially contacted with the isolation element 300. Therefore, when the thickness of the isolation element 300 is 2 mm, the minimum distance between the second metal radiant plate 400 and the first metal radiant plate 100 is 2 mm.
According to the second embodiment, the radiation heat exchange device further comprises a thermal insulation element 600, wherein the second metal radiant plate 400 and the first radiation heat exchange zone of the first metal radiant plate 100 are enclosed by the thermal insulation element 600 for preventing any heat loss therefrom. Particularly, the thermal insulation element 600 is mounted on the second plate surface of the first metal radiant plate 100 to enclose the heat exchange core plate assembly, and is sealed and mounted on the second plate surface of the second metal radiant plate 400 to form a thermal-insulated sealing cavity therebetween for preventing water vapor from entering into a space between the second metal radiant plate 400 and the first metal radiant plate 100 to form internal dew condensation. The radiation heat exchange device further comprises an outer casing 700 mounted on the second plate surface of the first metal radiant plate 100 to enclose the thermal insulation element 600 for forming the thermal-insulated sealing cavity. The outer casing 700 is configured to protect the thermal insulation element 600 from being damaged by any external force, and to reflect any external thermal radiation energy by an outer reflective surface of the outer casing 700. The outer reflective surface of the outer casing 700 can be a mirror surface. The thermal insulation element 600 is configured to isolate the heat transfer between the outer casing 700 and the second metal radiant plate 400.
According to the radiation heat exchange device of the second embodiment, two opening ends of the heat exchanging channel 500 are configured to pass through the thermal insulation element 600 and to extend out of the outer casing 700. The outer casing 700 has two through slots 702 formed thereat for the two opening ends of the heat exchanging channel 500 being extended out of the outer casing 700 through the through slots 701 respectively. The outer casing 700 further comprises two sealing rings 701 mounted at the through slots 702 and sleeved on the heat exchanging channel 500 for sealing the heat exchanging channel 500 around the through slots 702 where the heat exchanging channel 500 is extended out of the outer casing 700 so as to prevent any heat exchange through the through slots 702 of the outer casing 700.
According to the radiation heat exchange device of the second embodiment, the first metal radiant plate 100 and the second metal radiant plate 400 are preferably two aluminum plates, wherein the aluminum plates have the advantages of light weight, easy processing and low cost. It is appreciated that the first metal radiant plate 100 and the second metal radiant plate 400 can be two metal plates made of other thermal conductive material adapted for processing.
According to the radiation heat exchange device of the second embodiment, the heat exchanging channel 500 is embodied as a copper pipe. It is appreciated that the heat exchanging channel 500 can be made of other thermal conductive material. The heat exchange medium 502 can be any cold medium or heat medium for heat exchanging with the heat exchange core plate assembly. Preferably, the heat exchange medium 502 is in fluid form to flow along the heat exchanging channel 500 to remove the heat from the heat exchange core plate assembly.
According to the radiation heat exchange device of the second embodiment, the sub-near field gap 102 is formed between the second metal radiant plate 400 and the first radiation heat exchange zone of the first metal radiant plate 100, wherein the sub-near field gap 102 has a gap width defined as a distance between the second metal radiant plate 400 and the first radiation heat exchange zone of the first metal radiant plate 100. The minimum of the gap width is defined as 1-3 mm. Preferably, the gap width is configured to have 2 mm. It is worth mentioning that the first metal radiant plate 100 and the second metal radiant plate 400 will generate infrared radiation at their plate surfaces respectively. When the first metal radiant plate 100 and the second metal radiant plate 400 are located very close to each other, strong thermal radiation will occur, which is also known as near-field radiation. Specifically in the radiation heat exchange device, when the distance between the second metal radiant plate 400 and the first radiation heat exchange zone of the first radiant metal plate 100 is too close, through near-field radiation, the low temperature line of the heat exchanging coil during cooling will be projected onto the first radiant metal plate 100 to form an obvious cold temperature line. At this time, the plate surface of the first radiant metal plate 100 is easy for condensation at the corresponding position thereof, wherein when the distance between the heat exchange core plate assembly and the first radiant metal plate 100 is controlled at 1-3 mm, especially at 2 mm, the heat exchange core plate assembly and the first radiant metal plate 100 will have the strongest heat radiation heat exchange ability. Furthermore, during cooling, the first radiant metal plate 100 has no obvious low-temperature cold lines, which is defined as the sub-near field gap 102, to maximize the radiant heat exchange efficiency of the radiation heat exchange device of the present invention.
According to the radiation heat exchange device of the second embodiment, in order to ensure the sub-near field gap 102 being formed between the second metal radiant plate 400 and the first radiation heat exchange zone of the first metal radiant plate 100, the isolation element 300 is provided to ensure the first metal radiant plate 100 and the second metal radiant plate 400 being spaced apart from each other to form the sub-near field gap 102. Furthermore, the gap width of the sub-near field gap 102 can be selectively adjusted by the thickness of the isolation element 300. For example, the gap width of the sub-near field gap 102 can be enlarged by increasing the thickness of the isolation element 300. The isolation element 300 has the mesh structure and is made of low thermal conductive material. The isolation element 300 is configured to provide isolation and support functions, wherein the meshes of the isolation element 300 create spaces for radiation heat exchange. For optimizing the radiation heat exchange, the size of each of the meshes of the isolation element 300 can be enlarged. In other words, the larger the meshes of the isolation element 300 are, the better the radiation heat exchange is.
According to the radiation heat exchange device of the second embodiment, the second metal radiant plate 400 is in contact with the heat exchanging channel 500, such that the second metal radiant plate 400 is thermally conducted with the heat exchanging channel 500. It is appreciated that the larger contacting area between the second metal radiant plate 400 and the heat exchanging channel 500 is preferably provided to improve the efficiency of heat conduction. According to the second embodiment, the heat exchanging channel 500 has a circular cross section and is configured to have a S-shaped coil pipe to contact with the second metal radiant plate 400. Particularly, the heat exchanging channel 500 has a plurality of straight pipe portions parallel with each other and a plurality U-shaped curved pipe portions, wherein two ends of each of the curved pipe portions are communicatively connected to two ends of two of the straight pipe portions respectively, such that the heat exchange medium 502 is able to flow from one end of the heat exchanging channel 500 to an opposed end thereof through the straight pipe portions and the curved pipe portions. Accordingly, the straight pipe portions of the heat exchanging channel 500 are thermally contacted with the second metal radiant plate 400 and are disposed at the first indention grooves of the second metal radiant plate 400 respectively. It is appreciated that a length of each of the straight pipe portions of the heat exchanging channel 500 matches with a width of the second metal radiant plate 400. In other words, the curved pipe portions of the heat exchanging channel 500 are extended out of two opposed edges of the second metal radiant plate 400. The straight pipe portions of the heat exchanging channel 500 are covered by the coil bracket 800 to thermally contact the straight pipe portions of the heat exchanging channel 500 with the coil bracket 800. Accordingly, the straight pipe portions of the heat exchanging channel 500 are disposed at the second indention grooves of the coil brackets 800 respectively. In other words, bottom portions of the straight pipe portions of the heat exchanging channel 500 are disposed at the first indention grooves of the second metal radiant plate 400 respectively while upper portions of the straight pipe portions of the heat exchanging channel 500 are disposed at the second indention grooves of the coil brackets 800 respectively, such that the straight pipe portions of the heat exchanging channel 500 are enclosed between the second metal radiant plate 400 and the coil brackets 800. Preferably, each of the first and second indentions grooves has a semi-circular shape, wherein when the coil bracket 800 is coupled on the second metal radiant plate 400 at a position that the second indention groove is aligned with and extended along with the first indention groove, the accommodating channel is formed with a circular cross section to receive and retain the heat exchanging channel 500. The coil bracket 800 can be mounted on the second metal radiant plate 400 by crimping, bonding, welding or other mounting methods. Through this configuration, the coil bracket 800 and the second metal radiant plate 400 can be in close contact to form the heat exchange core plate assembly, so as to reduce the heat conduction gap with the heat exchange core plate assembly and to maximize the heat conduction efficiency with the heat exchange core plate assembly. Furthermore, the overall heat transfer of the heat exchange core plate is more uniform to reduce the effect of the heat transfer uniformity of the straight pipe portions of the heat exchanging channel 500. On the other hand, it also solves the problem of low temperature line that during cooling process, the temperature of the heat exchange medium 502 in the heat exchange coil plate assembly is further reduced to prevent any condensation. In addition, due to the uniformity of heat exchange, the temperature uniformity of the first radiant metal plate 100 can be further improved, wherein the entire first radiant metal plate 100 can be used for the temperature adjustment to the environment, which can greatly improve the heat exchange capacity of the radiation heat exchange device of the present invention.
According to the radiation heat exchange device of the second embodiment, the thermal insulation element 600 is mounted on the first metal radiant plate 100 to enclose the second metal radiant plate 400 and the first radiation heat exchange zone of the first metal radiant plate 100. Then, the outer casing 700 mounted on the first metal radiant plate 100 to enclose the thermal insulation element 600. Via the configuration of the thermal insulation element 600 and the outer casing 700, this configuration is able not only to effectively prevent the heat exchange between the heat exchange core plate assembly and the external environment to affect the heat exchange efficiency, but also to prevent the water vapor from the external environment entering into the outer casing 700, in result of forming internal condensation to affect the heat exchange efficiency. Since the outer casing 700 is sealed on the first metal radiant plate 100 to enclose the thermal insulation element 600, the thermal insulation element 600 is protected by the outer casing 700 from being damaged by any external force, and is formed with a second sealing cavity for preventing water vapor from entering into a space between the second metal radiant plate 400 and the first metal radiant plate 100. It is worth mentioning that the first sealing cavity is the thermal-insulated sealing cavity formed by sealing the thermal insulation element 600 on the first metal radiant plate 100. In other words, two different sealing cavities are formed for the heat exchange core plate assembly. Furthermore, the outer reflective surface of the outer casing 700, such as a mirror surface is able to reflect any external thermal radiation energy. Via the configuration of the thermal insulation element 600 and the outer casing 700, the heat exchange core plate assembly can be securely fixed and at the same time, the distance between the heat exchange core plate assembly and the first metal radiant plate 100 can be further retained.
According to the radiation heat exchange device of the second embodiment, two opening ends of the heat exchanging channel 500 are configured to pass through the thermal insulation element 600 and to extend out of the outer casing 700. The two sealing rings 701 are mounted on the outer casing 700 at the through slots 702 respectively and sleeved on the heat exchanging channel 500 for sealing the heat exchanging channel 500 around the through slots 702 so as to prevent any heat exchange through the through slots 702 of the outer casing 700. The radiation heat exchange device further comprises a connector head 501 coupled at each opening end of the heat exchanging channel 500. Via the connector head 501, two or more radiation heat exchange devices can be operatively connected with each other in a series or in parallel. Thus, the connector head 501 can also be connected to a pipeline of a heat exchange medium source to supply and receive the heat exchange medium 502 to and from the radiation heat exchange device.
According to of the second embodiment, the first metal radiant plate 100 is heat-exchanged with the second metal radiant plate 400 through the sub-near field gap 102 to regulate the temperature of the first plate surface of the first metal radiant plate 100 for regulating a temperature of the environment to be temperature-regulated. The temperature of the environment can be regulated via the cooling process or heating process of the radiation heat exchange device of the present invention.
According to of the second embodiment, the cooling process of the radiation heat exchange device comprises the steps of:
(a) absorbing an external radiant heat by the first metal radiant plate 100 and emitting the heat from the first metal radiant plate 100 to the second metal radiant plate 400;
(b) transferring the heat from the second radiant metal plate 400 to the heat exchanging channel 500; and
(c) removing the heat from the heat exchanging channel 500 by the heat exchange medium 502 as cold medium flowing in the heat exchanging channel 500, wherein the temperature of the heat exchange medium 502 is lower than the heat before heat exchange.
According to of the second embodiment, the heating process of the radiation heat exchange device comprises the steps of:
(1) supplying the heat exchange medium 502 as hot medium to flow in the heat exchanging channel 500 to transfer heat from the heat exchange medium 502 to the heat exchanging channel 500;
(2) transferring the heat from the heat exchanging channel 500 to the second radiant metal plate 400;
(3) emitting the heat from the second radiant metal plate 400 to the first radiant metal plate 100, wherein a temperature of the first radiant metal plate 100 is lower than that of the second radiant metal plate 100 before heat exchange; and
(4) emitting radiant heat by the first radiant metal plate 100 to an indoor environment. It is worth mentioning that the temperature at the plate surface of the first radiant metal plate 100 is increased to supply heat to the indoor environment.
The following tests are setup to verify the results of the examples.
An experimental room is set up to simulate the indoor environment, wherein the experimental room has a cube shape. The inner wall of a ceiling wall is a cold water radiant plate while the inner walls of the other five walls are hot water radiant plates respectively, such that the four surrounding walls and the floor are the hot water radiant plates to simulate the indoor environment.
The experimental method is that: The relative humidity of the simulated indoor environment inside the experimental room is controlled and maintained at 60%. Then, the cold water radiant plate as the ceiling wall is activated to adjust and maintain the cold water radiant plate at the preset temperature of 20° C. The five hot water radiant plates are then activated to activated to adjust and maintain the hot water radiant plates at the preset temperature of 26° C. so as to simulate the average radiant temperature of a real room indoor environment. At the same time, relevant parameters are detected and collected as follows: cold water inlet/outlet temperature, cold water flow rate, hot water inlet/outlet temperature, hot water flow rate, heat absorbed by the cold water radiant plate, and heat released by the hot water radiant plates.
The tests are divided into three groups:
Test A: For each of the cold water radiant plate and the hot water radiant plates, no heat radiation enhancing coating 200 is coated on neither the heat exchange core plate assembly nor the first radiant heat exchange zone of the first metal radiant plate 100. The minimum distance between the heat exchange core plate assembly and the first metal radiant plate 100 is set at 10 mm.
Test B: For each of the cold water radiant plate and the hot water radiant plates, the heat radiation enhancing coating 200 is coated on each of the heat exchange core plate assembly and the first radiant heat exchange zone of the first metal radiant plate 100. The minimum distance between the heat exchange core plate assembly and the first metal radiant plate 100 is set at 10 mm.
Test C: For each of the cold water radiant plate and the hot water radiant plates, the heat radiation enhancing coating 200 is coated on each of the heat exchange core plate assembly and the first radiant heat exchange zone of the first metal radiant plate 100. The minimum distance between the heat exchange core plate assembly and the first metal radiant plate 100 is set at 2 mm.
The results of the three test groups are shown in Table 1.
From the data and results shown in Table 1, by comparing test C and test B, it can be clearly concluded that the sub-near field gap 102 being set at 2 mm can significantly improve the radiative heat exchange efficiency. Comparing test C with test A, it is obvious that the heat radiation enhancing coating 200 and the sub-near field gap 102 can greatly improve the radiative heat exchange efficiency. Meanwhile, there was no condensation on the bottom surface of the first metal radiant plate 100 of the cold water radiant plate in Test C.
The radiation heat exchange device of the present invention can be used as a heat exchange unit for indoor or outdoor temperature regulation in residential buildings and public buildings. Specifically, the radiation heat exchange device can be configured as wall panels, ceilings, floor panels and the like. The radiation heat exchange device can also be configured as a heat sink for electronic systems, such as communication base stations, server equipment, computer and the like. It is appreciated that the radiation heat exchange device of the present invention can also be used in other relatively low temperature heat exchange conditions.
When the radiation heat exchange device 101 is used for ceiling, the size of the radiation heat exchange device 101 is sized to fit and mount on one unit of the metallic plate members F8, thereby the radiation heat exchange device 101 can be install onto the false ceiling conveniently to provide the air conditioning effect
It will thus be seen that the objects of the present invention have been fully and effectively accomplished. The 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.
| Number | Date | Country | Kind |
|---|---|---|---|
| 200810029359.6 | Jul 2008 | CN | national |
This is a Continuation-In-Part application that claims priority to U.S. non-provisional application, application Ser. No. 13/003,449, filed Feb. 23, 2011, which was the National Stage of and claims priority to international application number PCT/CN2009/072701, international filing date Jul. 9, 2009, the entire contents of each of which, including any amendment thereof, are expressly incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 13003449 | Feb 2011 | US |
| Child | 17936353 | US |
