Patent Application
20220034521
The present invention is in the field of room or space heating by a novel method using stored solar heat. More particularly, the present invention uses heat storing materials that absorb solar heat using reusable, inexpensive available materials along with a backup heating method when solar radiation is not sufficiently available.
Room heating is commonly done by using forced hot air, forced hot water, boiler and radiator, baseboard heater, electrical heater, etc. Using available sunrays, room heating can be accomplished by using stored solar heat. Since the sun doesn't shine all the time, storage of solar heat is very useful for later use when there is a demand for room heating. The present invention showed a novel method of storing solar heat for a long period of time and can be used later to heat the room air. Additionally, when the solar rays are not sufficiently available, an auxiliary heating system will generate enough heat for heating the house.
In accordance with one embodiment of the invention, the present invention relates to a method of storing solar heat in an insulated tank and heating up the room air using the stored solar heat. Solar heat can be stored in the insulated tank by using scrap and inexpensive abundantly available heat absorbing or heat storing materials. The stored heat can then be used to heat the room air by air circulation. Most homes are heated by using forced hot air using a thermostat. When the home temperature drops below the set point on the thermostat, circulating air pump turns on and pump the hot air until it reaches the desired set temperature. Once it reaches the set point in the thermostat air circulation pump turns off.
Above-mentioned and other features and objectives of this invention will become more apparent by reference to the following description taken in conjunction with the accompanying drawing, in which:
Typically concentrated solar power (CSP) uses solar rays to concentrate using mirrors and reflectors for generating electricity by using high heat generated by the CSP. The generated heat heats up molten salt to nearly 1050 F and can be used for generating steam. This steam can drive a steam turbine to generate large amount of electricity (1). In stead of generating large amount of electricity from the CSP, the present invention uses the concentrated solar rays to store heat for room or space air heating using scrap and inexpensive abundantly available heat absorbing or heat storing materials.
Sunrays are reflected from a mirror and directed through a lens (convex, Fresnel) or a parabolic mirror or a magnifying glass for concentrating incident solar rays into a heat insulted storage tank (HIST). High temperature resistant ceramic fiber blanket is used to insulate the storage tank. Ceramic blankets can withstand temperature in excess of 1800 F. Commercial manufactures, such as: Unitherm International, Unifrax, Thermaxx, Morgan Advanced materials supply thermal insulation product which can be used in the HIST. When a mirror is used, reflected rays pass through a quartz window and concentrated at the focal point by using a lens as shown in
Sand, steel and iron have a much lower specific heat than water and that's why sand gets hotter faster than water. Also rocks and stones are commonly used in sauna to store heat as they absorb heat, store and release that heat with time.
Some of the heat conducting materials such as: scrap aluminum, iron and copper plates, rods or filings are also placed inside the insulated tank. They are used for conducting the heat from the focal point of the solar rays to the surrounding heat absorbing materials inside the insulating tank for achieving a steady state temperature.
Thermal conductivity is a measure of material's ability for allowing heat to conduct. Denser material such as metals are good conductors whereas less dense materials and gases are poor conductor (called insulators). Thermal conductivity of selected materials is shown in Table 2.
The ideal heat storing or heat absorbing material should be dense and heavy so that it can absorb and retain significant amounts of heat. Scrap stainless steel, iron, sand, stone, concrete and marble are suitable for this purpose. They are abundantly available and inexpensive. Metallic material such as steel can retain or store heat as it remains hot for the longest period of time.
As the sun rays are focused either through a lens (light concentrator) and pass through a quartz window, or through a parabolic mirror and pass through a quartz window, intense heat is generated at the focal point. Intense heat is then transferred to the surrounding area using heat conducting materials such as scrap aluminum, and copper. Aluminum or copper can be in the form of plates, rods or filings. As concentrated solar rays at the focal point generate heat (as high as 500 to 600 C, referenced in 2-4), this heat is conducted through scrap aluminum or copper to the heat absorbing materials and stores the heat. When the steady state temperature in the heat absorber tank reaches say 500 F, room temperature air is circulated into the insulated HIST. The heated air is then passes through a duct to room as shown in
In order to control the temperature inside the solar HIST, a thermocouple (TC), such as Type-K, (5) with a temperature range of −328 to 2282° F. is placed inside the heat absorbing materials and it is connected to a digital controller, such as: Omega CN 740 series (6). Type K thermocouple is connected to one side of the temperature controller CN 740 and the lens shutter (S) is connected to the other side of the same controller. When the set point temperature say 500 F is reached, the controller shuts off the shutter so that reflected rays cannot go to the insulated heat absorbing tank (
When the room air temperature falls below the set point say 68 F, thermostat (T1) turns on the air circulating pump and the air circulator starts to flow the room air and extracts the heat and flows back to the room till temperature to reach 68 F, then the thermostat shuts off.
The mirror, parabolic mirror, shutter and quartz window (in
Even though solar energy can be collected during overcast or rainy days, its efficiency drops down significantly. On overcast or snowy days or when there are not enough solar rays available, there is an auxiliary back up heating system placed inside the HAT as shown in
A solar ray reflecting mirror or a parabolic mirror needs to track the path of the sun and keep its incoming rays focused at the focal point during the day (
In the present invention, a solar tracking system is used to track a mirror or a parabolic mirror which is smaller in size and less expensive, ranges from $147 to $569 (8-10). There are several newly developed products are commercially available.
Example 1. One such solar tracking product is Sun World's Sun Tracker (ST-600 Sun Tracker) (8). It is a single axis device that will follow the track of the sun from sunrise to sunset. This tracker is powered by using small solar panels. It is a self powered and self aligning design made by Solar Made (Patent pending).
Example 2. Another solar tracking product made by Eco-Worthy (9) is a dual axis solar tracking linear actuator controller complete electronic system—dual axis solar tracker kit with linear actuators, 12V system costs $147.
Example 3. Another commercially available solar tracking product is Sunflower3 made by Wikoda, Inc. (10). The Sunflower heliostat mirror continuously tracks the sun and reflects sunlight to a fixed spot. Throughout the day, it adjusts the sunlight to the required spot, such as to the lens in
