The invention relates generally to cooling and heating, and more particularly, to a system for electromagnetic cooling and heating.
In currently available cooling systems, as in refrigerators or AC units, a refrigerant is usually circulated with an electric pump, where the refrigerant takes heat from an enclosed area and releases it to the outside. In such an operation process, substantial electric power is consumed. When heat flow is reversed, the resultant system becomes a heat pump that heats a designated area, also requiring substantial electric power as well.
Therefore, what is needed is an apparatus and method for cooling and heating without external power sources.
In the proposed device, the cooling process is all passive and no electric power is needed to cool the area in an enclosed volume.
In accordance with principles of the invention, thermal energy is transferred from a hot region to a cold region via an electromagnetic device. For example, the cold temperature outside earth's atmosphere (“space”) can be utilized to pump heat from an enclosed volume on earth to the outer space. A relatively simple system of low cost at mass production can be made to do this. The system can be used for air-conditioning (AC) systems. With a proper design, it is possible to facilitate fast cooling analogous to rapid heating of food stuff achieved by a conventional microwave oven.
It is also possible to produce efficient heating by reversing the heat flow in the opposite direction compared to that in the cooling system.
An antenna is a device that takes power from an electromagnetic wave as a receiver while it can also be used as a transmitter of electromagnetic power. Depending on its surrounding area, an antenna can take thermal electromagnetic power at an infrared spectrum as well. The amount of thermal power radiated by an object is characterized by a black-body radiation temperature. When a high-gain antenna, such as a reflector antenna, points to the ground, the amount of power collected by the antenna is similar to that from a black body of the ground temperature. However, when the main beam is directed to the zenith of the sky, the power received by the antenna will be much smaller due to the fact that the radiation temperature of the open sky is substantially low, usually less than the freezing point of water.
A transmission line connects two antenna systems to transport electromagnetic power from a high-temperature area to a low-temperature region for electromagnetic cooling. In the antenna and transmission-line designs, there are two required conditions to make these antennas effective in electromagnetic cooling:
The transmission line has to be designed to reduce any added thermal power while electromagnetic waves propagate within the waveguide transmission line connecting two antennas at the ends of the transmission line. Metallic surfaces are convenient for antenna and transmission-line designs. However, metallic surfaces substantially add thermal power to the antennas and transmission line. Thus, it is recommended to have all dielectric antennas and transmission lines at frequencies of thermal agitation.
An antenna inside a region where heat is to be pumped to be cooled must have a broad beam to collect most of the electromagnetic power regardless of the incident angle, but an antenna outside the region must be highly directional or of high gain so that the antenna beam is pointed to a location of low effective temperature, such as the zenith of the sky.
Since the electromagnetic fields need to be confined within the dielectric transmission line, a cladding will reduce interaction with thermal agitation from the surrounding area. Also, a circular shape is easier to fabricate, as in optical fibers. The antenna at the tip of the transmission line can be tapered so that the electromagnetic power leaks out as the wave travels to the end without much reflection over a wide frequency range of the infrared spectrum.
The above system may also be used for heating when the chamber is colder than the region in the outside. In other words, the high-gain antenna should be pointed to the region where heat is coming from, such as the sun, and the low-gain antenna should be pointed to the region to be heated. Otherwise, the operation principles for cooling and heating remain the same.
For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
The following description is presented to enable any person skilled in the art to make and use the invention, and is provided in the context of a particular application and its requirements. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.
In the operation of system 100, antenna 104 in chamber 101 has a broad beam so that most of the thermal radiation within chamber 101 is collected by antenna 104 and transmitted to transmission line 103. The transmitted power propagates along transmission line 103 and reaches antenna 105 in chamber 102, where antenna 105 radiates the accepted power from transmission line 103 to a cool region of chamber 102. Both antennas 103 and 104 are preferred to have a relatively large bandwidth to cover most thermal radiation at the temperature of interest. Antennas 104 and 105 are preferably dielectric antennas to increase radiation efficiencies.
In the operation of system 300, antenna 302 inside chamber 301 has a broad beam so that most of the thermal radiation within chamber 301 is collected by antenna 302 and transmitted to antenna 303 via aperture 304 on the wall of chamber 301. Antenna 303 radiates the accepted power from antenna 302 to a cold region 305 such as the outer space. Antenna 303 preferably has a high gain for the radiated power to be focused to region 305. High-gain antennas include reflector antennas, horn antennas, and lens antennas as well as well-designed dielectric antennas. To increase radiation efficiencies, dielectric antennas can be used. Both antennas 302 and 303 are preferred to have a relatively large bandwidth to cover most radiation at the temperature of interest.
In the operation of system 500, electromagnetic power is coupled from below conducting plate 503 through coupling aperture 502 to form electromagnetic excitation within antenna 501 that radiates electromagnetic power in a focused beam. With a proper design, the focused beam is in the direction normal to conducting plate 503. The height of the dielectric antenna 501 is varied to change the antenna gain that shows the beam focus of radiated power. A circular cylinder of dielectric rod 501 is preferred for easy fabrication though other shapes are acceptable.
The above devices may also be used for heating when the temperature gradient of the two regions is switched. In other words, the high-gain antenna is pointed to the region where heat is coming from, and the low-gain antenna is connected to the region to be heated. Otherwise, the operation principles remain the same.
Having thus described the present invention by reference to certain of its preferred embodiments, it is noted that the embodiments disclosed are illustrative rather than limiting in nature and that a wide range of variations, modifications, changes, and substitutions are contemplated in the foregoing disclosure and, in some instances, some features of the present invention may be employed without a corresponding use of the other features. Many such variations and modifications may be considered obvious and desirable by those skilled in the art based upon a review of the foregoing description of preferred embodiments. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.
This application claims the benefit of U.S. Provisional Application No. 62/879,097 filed Jul. 26, 2019, which is hereby incorporated herein by reference, in its entirety.