JP4323615B2 - Cooling system for submersible submersible electric pump - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a cooling device for a submersible electric pump outside a tank.
[0002]
[Prior art and its problems]
As is well known, air-cooling radiating fins are stretched on the outer periphery of a motor frame of a motor used in the air. However, in order to cool the heat generated during operation of the submersible electric pump at a low water level by means of the radiating fins, an effect cannot be produced unless a very large heat radiating surface area is secured. The motor part of the submersible electric pump made on the assumption that it is used in the present condition is not provided with heat dissipation fins, and the space between the spiral chamber and the motor part is an oil chamber etc. Heat conduction is blocked by the presence. Therefore, when the motor unit is used in an extremely low water level exposed to the air, the motor cooling action during operation is extremely reduced, and the motor protection device is frequently started and stopped repeatedly. Will invite a motor burnout accident.
[0003]
As a countermeasure for preventing the motor cooling action at the low water level from being lowered, the water chamber 111 which is surrounded by the outer cover C and provided in an annular shape as shown in FIG. And the upper part of the water chamber 111 and the pump suction port 103 are communicated with each other by a circulation pipe P, and the heat generated by the motor is absorbed by circulation circulation when the pump is driven. However, if such a large and complicated structure is adopted, there are disadvantages that the whole pump is enlarged, the manufacturing cost is increased, the maintainability is poor, and the pump efficiency is lowered due to the circulation circulation.
[0004]
OBJECT OF THE INVENTION
An object of the present invention is to provide a cooling device for a submersible electric pump outside the tank that has a simple structure, can be manufactured at low cost, has excellent maintainability, and can maintain an effective cooling action without reducing pump efficiency.
[0005]
[Structure of the invention]
In the outside tank submersible electric pump cooling device according to the present invention, a first water chamber is provided between the spiral chamber and the oil chamber, and the second water chamber is provided from the outer periphery of the water chamber via a water passage. The first water chamber is electrically connected to the spiral chamber through a gap on the inner peripheral surface of the liner ring, and an air vent valve is attached to the upper end portion of the second water chamber.
[0006]
【Example】
Hereinafter, description will be made with reference to the drawings of the embodiments.
[0007]
Reference numeral 1 denotes a pump casing, the inside of which is formed in a spiral chamber 2, a suction port 3 is opened on the lower surface, and a discharge port 4 is led out on one side. 5 is an impeller accommodated in the spiral chamber 2 in a state of being mounted on the lower portion of the motor shaft 6, and 7 is a liner ring that fits with a boss portion of the impeller 5, and an inner peripheral surface thereof and the boss A gap g is formed between the outer peripheral surface of the part. 8 is an oil chamber containing lubricating oil of the shaft seal device 9, and 10 is a first water chamber provided between the spiral chamber 2 and the oil chamber 8, and sandwiches the inner peripheral surface of the liner ring 7. It is electrically connected to the spiral chamber 2 through the gap g. Reference numeral 11 denotes a second water chamber that is guided annularly from the outer periphery of the first water chamber via a water passage 12, and an air vent valve 13 is attached to the upper end of the second water chamber. A motor frame 14 is erected on the upper part of the oil chamber 8. And the principal part of these above-mentioned each members is made from heat conductive materials, such as a metal.
[0008]
[Action]
When the pump starts operation at a low water level where the motor unit is exposed to the air, a part of the pumped water is transmitted through the gap g on the inner peripheral surface of the liner ring 7 by the action of the water pressure generated in the spiral chamber 2. 1 flows into the water chamber 10, further passes through the water passage 12 and rises into the second water chamber 11, and the air in the water chamber 11 is exhausted from the air vent valve 13 to become full. A water cooling action by pumping water filled in the water chamber 11 is performed at a level higher than the water level on the outer periphery of the pump (minimum operating water level LWL). When the pump stops and the water pressure in the spiral chamber 2 decreases, the air is sucked from the air vent valve 13, and the pumped water absorbed by the motor heat descends in the second water chamber 11 and the water level on the outer periphery of the pump. When the same level as (minimum operating water level LWL) is reached and the operation of the pump starts again, new pumped water is filled in the second water chamber 11 and is used for absorption of motor heat. Thus, every time the pump starts and stops, it is automatically replaced with new pumped water, so that the cooling effect is maintained without changing from start to finish. Further, if the second water chamber 11 is guided to the outer peripheral portion of the motor frame 14, the water cooling effect is remarkably enhanced, so that it is not necessary to stretch the air-cooling radiating fins.
[0009]
【The invention's effect】
According to the cooling device for the submersible electric pump outside the tank according to the present invention, the pumped water in the water chamber is automatically replaced every time the pump starts and stops, so that an effective cooling action is performed from start to finish. Piping connecting the upper part of the out cover and the pump suction port is unnecessary, the structure is simplified, the pump efficiency is not reduced by circulation circulation, and no heat-radiating fins for air cooling are required. There is an advantage that it can be manufactured at a low cost and is excellent in maintainability.
[Brief description of the drawings]
FIG. 1 is a longitudinal side view of an essential part of a submerged submersible electric pump provided with a cooling device of the present invention.
FIG. 2 is a longitudinal sectional side view of a main part of a submerged electric submersible pump provided with a conventional cooling device.
[Explanation of symbols]
2 Pump's spiral chamber 7 Liner ring g Inner clearance of liner ring 8 Oil chamber 10 First water chamber 11 Second water chamber 12 Water passage 13 Air vent valve

Claims (1)

A first water chamber is provided between the swirl chamber and the oil chamber, and the second water chamber is guided annularly from the outer periphery of the water chamber through a water passage, and the first water chamber is located in the liner ring. A cooling device for an outside submersible submersible electric pump, wherein the cooling device is connected to a spiral chamber through a narrow gap on a peripheral surface, and an air vent valve is attached to an upper end portion of a second water chamber.

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