METHOD AND STORAGE SYSTEM OF PETROLEUM UNDER WATER
BACKGROUND OF THE INVENTION 1. Field of the Invention: The present invention relates to an oil storage method and more particularly, to an oil storage method under water, which keeps the oil tank under water in a Water pond so that the water in the water pond supports the pressure of the water pond and isolates the oil from storage of the land by means of the physical characteristic that the specific gravity is less than that of the water.
2. Description of Related Art: An oil storage tank can be mounted above or below the ground. When an oil tank is built on the ground, a strong floor construction must be built on the ground. The floor construction must be strong enough to withstand the heavy spherical or cylindrical steel armor of the oil tank and the oil stored in the oil tank. A conventional oil tank uses steel armor to withstand the pressure of the oil stored in it. The capacity has a limitation. In addition, increasing the capacity of the oil tank will increase the cost relatively. For safety, a retaining wall around the oil tank or tanks must be constructed, the spilled oil can still be kept inside the retaining wall to prevent contamination or any possible catastrophe. Currently, the capacity of the oil tank of Formosa Petrochemical Corp. is 130,000 square meters (the largest oil tank in the Pacific area of Asia). This oil tank has a diameter of approximately 86 meters and an approximate height of 24 meters. The steel armor of the oil tank must be strong enough to withstand the storage oil pressure of 24M deep and to provide a damping resistance against 6 degree earthquakes. It took approximately 2 years to finish the construction of the oil tank after the completion of the land construction. The total cost of this oil tank is approximately two hundred million US dollars. Because this oil tank is exposed to weather, it must be maintained regularly to remove corrosion and paint regularly. In the event of an oil leak, the storage oil must be completely discharged from the oil tank and cleaned so that a welding process can be used to seal the crack. Maintaining this oil tank is a difficult and expensive task.
In addition, when an oil tank is built directly underground, the cost is high. In the event of a spill, it is difficult to detect such spill, and the spilled oil will penetrate the soil contaminating the groundwater.
SUMMARY OF THE INVENTION The present invention has been achieved in view of the circumstances. Therefore, it is a main object of the present invention to provide a method of storage of oil under water, which uses water to isolate the oil from storage of the earth by means of the physical characteristic that the specific gravity is lower. that of water. It is another object of the present invention to provide a method of storage of oil under water, which automatically regulates the water level of the water that supports the oil tank, keeping the oil tank in equilibrium. It is still another object of the present invention to provide an underwater petroleum storage method, which keeps the oil tank under water in a water pond, preventing contamination of the storage oil in the surrounding land, and allowing a rapid visual inspection on an oil spill. To achieve these and other objects of the present invention, the method of underwater oil storage includes the steps of a) excavating a basement in the ground and constructing a wall structure in the basement to form a water basin; b) establishing an oil tank that has a predetermined shape and volume in the water tank; c) supplying a predetermined quantity of water to the water tank; and fill the oil that will be stored in the oil tank and regulate the amount of water in the water tank subject to the amount of storage oil stored in the oil tank where the oil to be stored has a specific gravity lower that the water filled in the water tank, and the amount of storage oil filled in the oil tank is less than the volume of the oil tank.
BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a flow chart of an underwater petroleum storage method according to the present invention. FIGURES 2A-2F illustrate the construction and operation of an underwater petroleum storage system according to a first embodiment of the present invention. FIGURES 3A-3F illustrate the construction and operation of an underwater petroleum storage system according to a second embodiment of the present invention. FIGURE 4 is a schematic sectional view of an underwater oil storage system according to a third embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED MODALITY With reference to FIGS. 1 to 2A, an underwater petroleum storage method according to the present invention includes the steps of: a) excavating a basement on the ground 10 and constructing a structure 20 of wall in the basement to form a water tank 30, where the wall structure 20 is a continuous concrete wall established on the vertical and horizontal lower peripheral sides of the cavity formed in the earth 10 for protection and insulation; b) establishing an oil tank 40 in the water tank 30 and directly supporting the oil tank 40 in the bottom wall 31 of the water tank 30, where the oil tank 40 can be a metal, concrete or plastic container or a container made of any variety of petroleum-proof materials subjected to a predetermined size and having an oil access port 41 on the upper side thereof and at least one lower port 42 on the underside thereof in communication with the interior space of the water tank 30 to allow water to flow through the lower port 42 between the water tank 30 and the oil tank 40; c) supply a predetermined amount of water
W to the water tank 30, where the water W can be city water, sea water, industrial waste water which is maintained in the water tank 30 by the wall structure 20; the predetermined amount means that an automatic supply and flow adjustment mechanism is provided to control the amount of water in the water tank 30 subject to the type of oil tank 40 and the volume of oil stored in the oil tank 40; and d) filling the oil 0 in the oil tank 40 through the oil access port 41, where the oil O may be crude oil, gasoline, mineral oil, animal oil, vegetable oil, or any of a variety of fluids chemicals of specific gravity smaller than 1; the amount of oil fill O is less than the volume of oil tank 40 so that the oil O filled in the oil tank 40 does not flow out of the oil tank 40 into the water tank 30 and then floats in the water W in the pond 30 of water outside the tank 40. With reference to FIGURES 2B and 2C, because the specific gravity of the oil 0 (normally around 0.9) is less than the specific gravity (1) of the water W, the O oil will float in the water W in the 40 oil tank when the oil O is filled in the 40 oil tank through the 41 port of oil access, and the W water will be gradually forced out of the 40 oil tank in the water tank 30 subjected to the increase in the amount of oil filling O. Because the volume of the water tank 30 is constant, filling the oil O in the oil tank 40 causes an increase in the water level in the tank. the pond 3 0 of water. The invention further provides a spare water tank 50 on one side of the water tank 30 at the same level. A connecting pipe 51 is provided horizontally between the water tank 30 and the replacement water tank 50 near the upper side. When the water level in the water tank 30 exceeds a predetermined high level, the water W flows out of the pond 30 of water in the water tank 50 through the connection pipe 51 for additional use. With reference to FIGURES 2D-2F, when oil O is pumped out of the oil tank 40 through the oil access port 41 for use, the amount of oil 0 in the oil tank 40 will be gradually reduced, the Water level W in tank 40 of oil will be increased gradually to lift oil 0 in tank 40 of oil, and water level W in pond 30 of water outside tank 40 of oil will be gradually lowered. At this time, the stored water can be guided from the water tank 50 into the water tank 30. According to this embodiment, an automatic water control system 52 is provided which is formed of a water pump and a water level sensor for detecting the water level in the water tank 30 and automatically pumping the water out of tank 50 of water in pond 30 of water when the level of water W in pond 30 of water falls below a predetermined margin. Therefore, the amount of water in the water tank 30 and the oil tank 40 is automatically adjusted by the amount of oil 0 in the oil tank 40, allowing the water to support the gravity weight of the oil tank 40. oil and keep the 40 oil tank in balance. As indicated in the above, the invention uses the water in the water tank 30 to isolate the O oil from the earth and to support the gravity weight of the oil tank 40 and the O oil contained in the oil tank 40 and to maintain the oil tank 40 in equilibrium by means of the physical characteristic that the specific gravity of the oil 0 is less than that of the water W. In an application example of the present invention, the oil tank 40 in the tank 30 of water has a depth of 24 meters. When the oil tank 40 is filled to the top with oil O of specific gravity 0.9, the level of the oil O in the oil tank 40 is 2.4 meters above the water level in the water tank 30. At this time, the water supports and begins 90% of the pressure, and the oil tank 40 supports only the other 10% of the pressure. Therefore, when designing the material strength of the material for the oil tank 40, you only need to consider the O oil pressure of 2.4 meters depth but not the oil pressure OR 24 meters depth. When oil O of specific gravity 0.99 is stored, the water W in the water tank 30 supports and starts 99% of the pressure, and the oil tank 40 supports only 1% of the pressure. Therefore, the invention breaks the conventional concept of building an oil tank with thick steel plate members. When building an oil tank of 130,000 square meters of volume (24M Height x 86M Diameter), you only need to build a concrete wall structure of 24M Height x 76M Length x 76M Wide (saving approximately one area) of earth of 10M x 10M). By joining the reinforcing steel wire rods, establishing the molds, emptying the concrete, and removing the molds after setting the concrete, the desired wall structure 20 is constructed, and the oil tank 40 then designed can be established in the water tank 30 formed in this way. In addition, using plastic or stainless steel plate members to build the wall structure 20 instead of concrete accelerates the construction speed. Because the oil tank 40 is established in the pond 30 of water under the ground, it is not necessary to build an additional retaining wall to protect the oil tank 40 from earthquakes or any destructive behavior of humans. Because the 40 oil tank is established under the ground, it is safe against the destructive behavior of human beings, and the storage O oil is free from the effect of the surrounding water. In addition, no lightning conductor or similar is necessary. In case of an earthquake, the water in the water tank 30 absorbs the shock waves. Because the oil tank 40 bears a small pressure, the manufacturing cost of the oil tank 40 can be greatly reduced. FIGURES 3A ~ 3F show an alternative form of the present invention. According to this embodiment, the oil tank referred to by 40a has an oil access port 41 on the upper side, however, the oil tank 40a has no port on its underside. Further, frames 43 are fixedly provided in the bottom wall of the oil tank 40a and are supported on the upper side of the bottom wall 31 of the water tank 30, allowing water to flow through the underside of the oil tank 40a, however, the storage oil O is not allowed to pass outside the 40a oil tank in the water W in the water tank 30. When the oil or storage is filled in the oil tank 40a, the water W is simultaneously filled into the water tank 30 by means of the control of the automatic water control system 52, and therefore, the water level in the water tank 30 and the oil level of the oil OR in the oil tank 40 rise synchronously (see FIGURES 3A ~ 3C). In contrast, when oil O is pumped out of the 40a oil tank for use, the automatic water control system 52 automatically pumps the water W out of the water tank 30 into the water tank 50, maintaining the water pressure in pond 30 of water in equilibrium with the pressure of tank 40a of oil (see FIGURES 3D-3F). In addition to the aforementioned large scale design, the invention can also be applied for a relatively smaller scale design for use in, for example, a gas station. According to a third embodiment of the present invention shown in FIGURE 4, an upper cover 21 is covered in the wall structure 20 to close the water tank 30; the petroleum tank 40b is fixedly supported in a frame 43 '(or frames 43') on the lower wall 31 of the water tank 30 against the floating of the water W in the water tank 30, which has an access port 41 oil, which is comprised of an oil inlet pipe 41a and an oil outlet pipe 41b extending respectively upwards from the upper side of the oil tank 40b to the outside of the upper deck 21, and a pipe 41c of air equipped with a discharge valve (not shown) and extending upwards to the outside of the water tank 30 for the discharge of air when the air pressure in the oil tank 40b exceeds a predetermined level. The operation of this embodiment is substantially similar to the aforementioned second embodiment with the exception that the water level in the water tank 30 exceeds the elevation of the upper side of the oil tank 40b, i.e. the oil tank 40b is It constantly holds under water W. Preferably, the oil tank 40b is mounted in the frame 43 'at an angle of inclination, which has a portion 44 of water tank lowered into the lowest area in the interior and connected to a sensor 45 of external water through a connection line. In case the water spills in the oil tank 40b, the leaky water will accumulate in the lowered water tank portion 44 and will be detected by the water sensor 45, and a repair work can be quickly employed to avoid additional damage. In case a positive pressure type oil tank 40b has a damage and oil O spills out of the 40b oil tank, the oil spilled will float in the water, and the worker at the gas station can easily find the problem and take the necessary steps to eliminate the problem. Like the various aforementioned embodiments of the present invention, this method uses water W to isolate oil 0 from the terrestrial soil, avoiding contamination in the surrounding earth. In addition, the water is used in the water tank 30 to support the 40b oil tank and the oil pressure OR storage in the 40b oil tank. In general, the invention provides an oil storage system under water, which uses the water to support an oil tank and the storage oil in the oil tank and to keep the oil tank in equilibrium, presenting oil contact. storage oil with the earth. Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and improvements can be made without departing from the spirit and scope of the invention. Accordingly, the invention will not be limited except by the appended claims.