Integrated Dehumidification Method and System Combining Boundary Layer Control with Mainstream Disturbance Enhanced Heat Exchange
An integrated dehumidification method and system that combines boundary layer control with mainstream disturbance enhanced heat exchange; a boundary layer flow control device is arranged on the flow boundary layer; and a mainstream disturbance device is arranged on the main runner to realize adequate heat exchange. An integrated dehumidification system that combines boundary layer control with mainstream disturbance enhanced heat exchange, wherein numerous boundary layer flow control devices are longitudinally arranged parallel near the vane on the refrigerating terminal adjacent to all the wall surfaces; a mainstream disturbance device is arranged on the main flow runner; the vane on the heating terminal is in the same arrangement. It achieves integrated, smooth and efficient heat exchange, presenting a novel method and system for enhanced heat transfer. The multi-channel dehumidification can improve the treatment efficiency greatly.
This invention is involved with dehumidification, in particular, an integrated dehumidification method and system combining boundary layer control with mainstream disturbance enhanced heat exchange.
BACKGROUND OF THE INVENTIONQuick dehumidification of humid air or other process gases is an important issue associated with daily life and with numerous industrial applications.
Due to the increased public demands for the quality of air, food and medicines humidity control in the production and living environments has become increasingly important. In the industrial field, the existence of humid air and condensate may directly result in corrosion and malfunction of instruments and parts, or even failure of the corresponding process system. Meanwhile, humidity will inevitably lead to a change in the features of process materials with adverse effects on production. In our daily life, humidity is a fundamental factor in the growth of mold and a main factor for lesion. As a result, the transmission of pathogenic bacteria and pollutants to the air and the human body will be quickened. Studies show that the appropriate humidity for the human body (depending on the location and the seasonal ambient temperature) should be controlled to be 40-65%. The independent control of air humidity has become an inevitable development trend, however, in view of the energy crisis and environmental deterioration, it is obvious that development of a dehumidification process and system with high efficiency and energy conservation is the ultimate goal for dehumidification techniques.
The existing mature dehumidification techniques mainly include cooling dehumidification, liquid absorption dehumidification, solid absorption dehumidification, HVAC (heating, ventilation and air conditioning) dehumidification and the reel absorption dehumidification, developed on the basis of the solid absorption dehumidification techniques. With the transition of semiconductor cooling and heating techniques from the aeronautical and aerospace field to the civil field, the application of a novel dehumidification technique, thermoelectric cooling dehumidification has become more and more widely used to meet the demand for energy conservation and emission reduction.
Cooling dehumidification is to make use of a natural or artificial cooling source to cool humid air till reaching a temperature below the dew point, so as to remove the water vapor that exceeds the saturated humidity from the humid air in the form of condensate. The freezing dehumidifier is the most representative cooling dehumidification equipment. The freezing dehumidifier normally comprises of refrigerant compressor, evaporator, condenser, expansion valve, draught fan and air valve. This is the earliest and maturest dehumidification technique featuring low initial investment, high COP, reliability, convenience and no need for a heat source. And this technique is the most widely used one in our daily life. However, as this technique adopts the Carnot cycle, the refrigeration agent eventually has an adverse impact on the environment. Also, despite the high COP, coupling process systems comprising multiple machines inevitably result in excessive consumption of electrical energy. This type of dehumidification system is also inappropriate for application at adverse ambient temperature (extremely high or low), and is not easy to maintain. Due to these problems of environmental impact and extremely high energy consumption, its application will be subject to more and more stringent control.
Liquid absorption dehumidification is to use a liquid drying agent to absorb vapor from humid air under the action of pressure gradient in view of the fact that the partial pressure of the vapor on the surface of the drying agent is lower than that in the humid air. This ensures consistent vapor partial pressure between the air and the agent. Liquid drying agent shall be dewatered for reuse. A typical liquid absorption dehumidification device comprises of dehumidifier, regenerator, vapor cooler, heat exchanger and pump. Liquid absorption dehumidification equipment boasts of a high processing capacity and a great dehumidification effect. Furthermore, the liquid drying agent can purify the air by absorbing such hazardous substances as partial pathogenic bacteria and chemical pollutants in the air in addition to the absorption of vapor. Liquid absorption requires the heat regenerated by the drying agent. Such heat can be obtained from low-grade heat sources, such as solar energy and industrial waste heat, which makes low energy consumption possible. But in this case, it is necessary to consider the stability of the heat source. The investment amount and coverage area will also change accordingly. As the overall coverage area of liquid absorption dehumidification equipment is greater than that of a freezing dehumidification devices, constant maintenance is required. In view of relatively low COP of the system the corrosion of the drying agent to equipment and the control of liquid flow (prevention of droplets), this mode is mainly suitable for industrial application.
Just like liquid absorption dehumidification, solid absorption dehumidification is to use a drying agent to absorb vapor from the air. The only difference is that the drying agent is solid. The drying agent may release large quantities of heat during absorption of vapor. To maintain a great absorption capacity, it is necessary to cool the drying agent during absorption, which inevitably results in increased energy consumption. Reel absorption dehumidifier is the most typical solid absorption equipment, mainly comprising of drying reel, regenerating heater, dehumidification draught fan and regenerating fan. In the reel absorption dehumidification equipment, the damp air and regenerated air are delivered via the fans. And the rotation of the reel results in great noise. So regular mechanical maintenance is required. The higher the absorption capacity of the drying agent on the reel is, the higher the energy consumption during regeneration will be, and the higher temperature the regeneration process will require. Additional cooling equipment is required according to environmental requirements when necessary. Compared with cooling dehumidification, the solid absorption dehumidification technique features low COP and high dehumidification capacity, which is particularly applicable to treatment of air at low temperature and low humidity. The main applications are in industrial production processes.
With higher levels of production and increased living standards, awareness of environmental protection and energy conservation has been further enhanced. Various technical approaches and methods have been adopted to improve technological efficiency. And, more and more technological processes have been developed for greener or cleaner production. It is the same for dehumidification techniques. The development of green and environment-friendly processes and the technological innovation for energy conservation have become an inevitable development trend in the industry. In recent years, energy consumption and pollution (emission of CO2 and leakage of Freon), related to conventional air conditioning systems, have witnessed a continuous increase accompanied by an increase in the demand for air conditioning worldwide. Presently, the proportion of energy consumption for air conditioning is over 15% and increasing. Vapor content in the air varies significantly with regional features and the change of seasons. Due to the high latent heat produced by evaporation, dehumidification has become one of the main energy consumption parts of the air conditioning system, accounting for 20-40% of the total energy consumption of the air conditioning system. Improvements in dehumidification methods are an important step for energy conservation of air conditioning systems. Thermoelectric and cooling dehumidification techniques are based on the Peltire effect and the Beck effect, which is the application of thermoelectric refrigeration principles in the dehumidification process. This is characterized by small volume, high stability, no need of refrigerant or drying agent and environment-friendliness. This is an advanced technique in the field of dehumidification. Owing to the integration of the cooling and heating functions, thermal condensing dehumidification performs cooling and heating treatments simultaneously, resulting in low energy consumption. Compared with conventional condensing dehumidification systems, the overall power and energy consumption are significantly reduced. This system can use solar energy as the source of electric energy. And the adjustment of the condensing and heating effect through controlling the current flow is simply controlled. This ease of control ensures high stability for the whole dehumidification process. The thermoelectric device has a working life of over 100,000 hours, which far exceeds that of conventional condensing dehumidification equipment. With the exception of the low-power fan used for air flow and condensation, the equipment is free of mechanical transmissions throughout the whole dehumidification process; it features low noise, quick start-up and less stringent environmental requirements. As the ambient operating temperature is between −40 and 70° C., it is available for operation in extreme environments, and can be adapted to the designated working zones at will. In conclusion, this will inevitably become an important direction and method for the future development of dehumidification techniques.
However, the thermoelectric dehumidification technique has such problems as the existence of a boundary layer that affects the heat transfer mechanism and the difficulty in are the full heating and cooling of mainstream short flows, which might make it hard for efficient heat exchange and thus greatly affect the dehumidification efficiency.
SUMMARY OF THE INVENTIONIn view of such defects as the boundary layer, mentioned above, that may affect cool and heat transfer and mainstream short flows inadequate for heating and cooling, this invention provides an efficient solution to the cool and heat transfer affected by the boundary layer; it forms an efficient integrated dehumidification method and system with boundary layer control combined with mainstream disturbance enhanced heat exchange through elimination of the restriction of inadequate mainstream short flows insufficient for adequate heating and cooling.
The following technical solutions are used by this invention to achieve the aforesaid purposes:
The integrated dehumidification method that combines boundary layer control with mainstream disturbance enhanced heat exchange aims to form an axial periodical eddy current along the flow channel through arrangement of boundary layer flow control devices in the boundary layer to facilitate air cleaning on cooling and heating side walls, which overcomes the boundary layer heat exchange restriction and rapidly transfers cooling and heating capacity from the side walls to the main airflow. This differs from other conventional boundary layer control ideas. It is a novel method to enhance heat transfer through flow control in the boundary layer. From the point of view of flow control and the enhancement of heat transfer, the integration of inertia separation and multi-stage condensation significantly improves the efficiency of gas-liquid separation simultaneously with further condensation treatment. Air from the condensation treatment section is supplied at a lower absolute humidity (energy consumption is much lower when the absolute humidity of the mixed gasses are of the same value); meanwhile, the method of boundary layer disturbance is selected to improve heat transfer efficiency in the heat treatment section; this air flow organization prevents overheating in the heat treatment section. Conversely, consistent air temperature at the outlet and a corresponding increase in overall temperature are favorable for drying or for storage.
Preferably, the mainstream disturbance device is deployed in the mainstream channel, the eddy current along the mainstream channel is then forced to interact with the flow from the boundary layer; this quickly transfers cooling and heating capacity from the boundary layer to the main flow so as to form a uniform temperature field, thus improving the cooling and heating exchange efficiency of the flow channel.
Preferably, the boundary layer flow control device is a disturbance cylinder in an axial arrangement along the flow channel on the boundary layer. The created coherent structural turbulent wake flow of the cylinder enhances contact between the air and both cooling and heating walls to ensure enhanced condensing separation and heat transfer.
Preferably, the mainstream disturbance device is a delta, oval or circular wing in an axial arrangement along the flow channel.
An integrated dehumidification method that combines boundary layer control with mainstream disturbance to enhance heat exchange, comprising of insulating case, with a semiconductor thermoelectric device in the insulating case. This semiconductor thermoelectric device comprises of a cold terminal below and a hot terminal above. The well conductive refrigerating vane assembly is connected to the lower part of the cold terminal longitudinally along the flow direction to make up for the multi-flow channels; the right side of the refrigerating vane assembly is connected to an air inlet, a catchment trough with drain is deployed below the vane assembly on the refrigerating terminal; the lower part of the catchment trough is equipped with a drain. The well conductive heating terminal vane assembly is also connected to the lower part longitudinally to make up for the multi-flow channels along the flow direction, and the right end of the vane assembly on the heating terminal is connected to the air vent. The flow direction is parallel to the cold terminal surface and the cold terminal is situated above the incoming flow, therefore the flow passing below the vane assembly ensures adequate condensation. In this way the air is uniformly treated in the whole section and the cooling effect of the refrigerating terminal is maximized in the airflow, with minimum temperature variation attained by adequate contact with the enlarged vanes on the refrigerating terminal. The boundary layer flow control device forms an axial periodical eddy current along each flow channel, which facilitates maximum air contact with the cooling and heating side walls. By disrupting the boundary layer affecting the heat exchange, it rapidly transfers the hot and cold air from side walls to the main flow.
Preferably, at least one mainstream disturbance device is provided at the center of the refrigeration vanes. The eddy current along the mainstream channel is formed in coordination with the flow from the boundary layer from the mainstream disturbance device, this rapidly transfers hot and cold air from the boundary layer to the whole field to form a uniform temperature field, thus improving heat exchange efficiency in the flow channel.
Preferably, the boundary layer flow control device is a cylinder in axial arrangement along every flow channel.
Preferably, the mainstream disturbance device is a group of delta or oval or circular wings arranged in axial arrangement along the flow channel.
Preferably, the refrigeration vanes on the refrigerating terminal have longitudinal cross sections with trapezoid profiles to ensure that water drops, separated through condensation, flow into the catchment trough along the lower surface for discharge.
Preferably, the cross section between each two vanes on the refrigerating terminal is in a ‘W’ profile, which ensures adequate air space between each vane and also prevents any blockage occurring in the central cooling channel. Parallel channels between each two W-shape vanes cause inertial gas-liquid separation through changing flow direction. The directionally changed air is imposed with inertial force that ensures the effect of cooling treatment simultaneously with inertia separation and wall surface contact.
Preferably, a screen mesh is provided on the given vane surface of the refrigerating terminal to employ the tensile force on the water surface to prevent secondary crushing of the condensate, and to ensure tracking.
Preferably, at least one boundary layer flow control device is provided longitudinally adjacent to all the neighboring wall surfaces.
Preferably, at least one mainstream disturbance device is longitudinally arranged at the center between each two vanes on the heating terminal.
The integrated dehumidification method that combines boundary layer control with mainstream disturbance enhanced heat exchange of this invention has the following advantages: First, in respect of flow control and enhancement of heat transfer, the integration of inertia separation and multi-stage condensation can significantly improve the efficiency of gas-liquid separation simultaneously with further condensation treatment. Air from the condensation treatment section is provided with lower absolute humidity (energy consumption is much lower when the absolute humidity of the mixed gasses are of the same value). Secondly, boundary layer disturbance improves heat transfer efficiency in the heat treatment section; and directed air flow organization prevents overheating in the heat treatment section. Thirdly, consistent air temperature at the outlet and the corresponding increase in overall temperature are favorable for drying or storage.
This invention is to be further described in detail in combination with Drawings 1-5 and specific implementation as follows:
An integrated dehumidification method that combines boundary layer control with mainstream disturbance enhanced heat exchange, characterized in that boundary layer flow control device is deployed on the flow boundary layer; a mainstream disturbance device is arranged on the main flow runner; the said boundary layer flow control device is provided with a turbulence inducing cylinder in axial arrangement on the boundary layer along the flow channel; the said mainstream disturbance device is a delta wing in axial arrangement on the main runner along the flow channel.
Example 1An integrated dehumidification method that combines boundary layer control with mainstream disturbance enhanced heat exchange as shown in
An integrated dehumidification method that combines boundary layer control with mainstream disturbance enhanced heat exchange as shown in
An integrated dehumidification method that combines boundary layer control with mainstream disturbance enhanced heat exchange as shown in
Specific configurations are stated as follows relevant to different industrial applications of this invention:
Domestic dehumidification: Domestic dehumidification mainly involves the storage and quick drying of articles in rainy seasons (hanging articles on the heating terminal); furthermore, it is also highly suitable to provide high-quality air at home. With regard to the wet and cold regions in the Yangtze River basin, this invention can supply separate heating and dehumidification to enhance the user's environment while ensuring low energy consumption. When compared with various conventional heating approaches, it will inevitably improve air treatment efficiency owing to its characteristics of separate heating and dehumidification.
Industrial dehumidification: In view of industrial dehumidification, efficient separation with aerosol has a promising prospect. Conventional dehumidification is normally achieved by means of inertia separation, intercepted separation and filtration with wire mesh, which requires high energy consumption. However, this type of dehumidification is inefficient for aerosol of small grain size in respect of high motion tracking. Efficient separation of aerosol with low energy consumption is a critical problem. Through the full integration of the dual effects of flow control and condensation treatment, this invention can significantly improve the efficiency in the separation of aerosol and vane drips at extremely low energy consumption, beyond the reach of conventional dehumidification methods.
Storage of articles: Articles that are to be stored at constant humidity and temperature. Conventional dehumidification is carried out with methods requiring high energy consumption, such as refrigerated circulating dehumidification, which has the disadvantages of high price and low efficiency. Creation of a suitable air environment for storage in a quick and efficient manner at low energy consumption has considerable application value. The processing device provided by this invention provides suitable temperature and humidity in confined spaces, providing high-quality air to facilitate the long-term storage of articles.
Portable artificial environment: Another important advantage of this invention is that it is available for integration with such new energies and energy conservation techniques as solar energy. Owing to its light weight and small volume, it can provide users with a high-quality air confined space when configured as an enclosed unit through the application of multilayer technology for the space chamber. It is applicable in such special fields as camping, field hospital and archaeological studies.
Comprehensive techniques for economical air circulation system in high-humidity environments: Another application of this invention in a high-humidity environment is in the filtration and disinfection of large quantities of condensate produced by dehumidification in the process of unit dehumidification to provide high-quality potable water at low energy consumption. This method is applicable to various offshore industrial fields or high-humidity regions lacking in water. Whilst providing customers with a comfortable air environment, it can also provide quantities of potable water, thereby forming an economical and comprehensive technical circulation system.
Claims
1. An integrated dehumidification method combines boundary layer control with mainstream disturbance enhanced heat exchange, characterized in that it forms axial periodical eddy currents along the flow channel through the arrangement of boundary layer flow control devices on the boundary layer so as to facilitate air contact with the cooling and heating side walls; in one aspect, it overcomes the boundary layer's adverse effect on heat exchange, also, it rapidly transfers the differential temperatures generated by the cooling and heating side walls to the mainstream flow.
2. The integrated dehumidification method combines boundary layer control with mainstream disturbance enhanced heat exchange according to claim 1, characterized in that the mainstream disturbance device is arranged within the mainstream airflow channel; the eddy current along the mainstream channel is coordinated with the flow from the boundary layer under the effect of the mainstream disturbance device. This rapidly transfers cooling and heating capacity from the boundary layer to the whole field to form a uniform temperature field, and improves cold and heat exchange efficiency inside the flow channel.
3. The integrated dehumidification method combines boundary layer control with mainstream disturbance enhanced heat exchange according to claim 1, characterized in that the boundary layer flow control device is a disturbance cylinder in axial arrangement along the flow channel on the boundary layer.
4. The integrated dehumidification method combines boundary layer control with mainstream disturbance enhanced heat exchange according to claim 2, characterized in that the mainstream disturbance device is a group of delta or oval or circular wings in axial arrangement along the flow channel on the main runner.
5. An integrated dehumidification system combines boundary layer control with mainstream disturbance enhanced heat exchange, comprising an insulating case (1), a semiconductor thermoelectric device (2) in the insulating case (1), which is characterized in that the semiconductor thermoelectric pair (2) comprises a cold end (3) below and a hot end (4) above; vane assembly on the refrigerating terminal (5) is connected below the cold end (3); upstream side of the vane assembly on the refrigerating terminal (5) is connected with an air inlet (6); a catchment trough (7) is arranged below the vane assembly on the refrigerating terminal (5); a drain (8) is provided below the catchment trough (7); vane assembly of heating terminal (9) is connected above the hot end (4); downstream end of the vane assembly on the heating terminal (9) is connected with the air vent (10); the vane assembly on the refrigerating terminal (5) comprises at least two vanes on the refrigerating terminal (11) arranged longitudinally; the vane assembly on the heating terminal (9) comprises at least two vanes on the heating terminal (14) arranged longitudinally; the vane on the refrigerating terminal (11) is provided with at least one boundary layer flow control device (12) longitudinally arranged adjacent to the wall surface.
6. The integrated dehumidification system combines boundary layer control with mainstream disturbance enhanced heat exchange according to claim 5, characterized in that at least one mainstream disturbance device (15) is longitudinally arranged at the center of the vane on the refrigerating terminal (11).
7. The integrated dehumidification system combines boundary layer control with mainstream disturbance enhanced heat exchange according to claim 5, characterized in that the said boundary layer flow control device (12) is a turbulence inducing cylinder in axial arrangement along the flow channel.
8. The integrated dehumidification system combines boundary layer control with mainstream disturbance enhanced heat exchange according to claim 6, characterized in that the said mainstream disturbance device (15) is a triangular or oval or circular vane in axial arrangement along the flow channel.
9. The integrated dehumidification system combines boundary layer control with mainstream disturbance enhanced heat exchange according to claim 5, characterized in that the longitudinal section of the said vane on the refrigerating terminal (11) is of trapezoidal profile.
10. The integrated dehumidification system combines boundary layer control with mainstream disturbance enhanced heat exchange according to claim 5, characterized in that the cross section of the said vane on the refrigerating terminal (11) is ‘W’ shape.
11. The integrated dehumidification system combines boundary layer control with mainstream disturbance enhanced heat exchange according to claim 10, characterized in that a screen mesh (13) is provided on the surface of the vane on the refrigerating terminal (11).
12. The integrated dehumidification system combines boundary layer control with mainstream disturbance enhanced heat exchange according to claim 5, characterized in that the said vane on the heating terminal (14) is provided with a boundary layer flow control device (12) longitudinally at the position adjacent to the wall surface.
13. The integrated dehumidification system combines boundary layer control with mainstream disturbance enhanced heat exchange according to claim 5, characterized in that at least one mainstream disturbance device (15) is longitudinally arranged at the center of the channel on the heating terminal (14)
Type: Application
Filed: Jan 28, 2012
Publication Date: Jan 30, 2014
Applicant: Wenling Anneng Energy Efficency Technology Co., Ltd. (Wenling, Zhejiang)
Inventor: Xiaohua Wang (Wenling)
Application Number: 14/112,758
International Classification: F25B 21/04 (20060101);
