System for controlling hydraulic drive for cooling fan in cooling tower
First Claim
1. A system for controlling a hydraulic drive for a cooling fan in a cooling tower, comprising a hydraulic motor connected to the cooling fan, a variable displacement pump connected to said hydraulic motor via a hydraulic pressure supply line and driven by a motor, a flow control valve arranged in said hydraulic pressure supply line, a temperature detector for detecting supply water temperature in the cooling tower, a controller for controlling said flow control valve based on a difference between a temperature detected by said temperature detector and a preset temperature and a pressure-compensated variable displacement regulator for controlling capacity of the variable displacement pump to maintain irreducibly minimum pressure difference between pressure on upstream side and pressure on downstream side of the flow control valve in said hydraulic pressure supply line.
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Accused Products
Abstract
Supply water temperature in a cooling tower is detected by a temperature detector, and based on the temperature detected by the temperature detector, a flow control valve in a hydraulic pressure supply line is controlled. As a result, operation of a hydraulic motor connected to a cooling fan can be controlled to efficiently cool down the water temperature to reach a preset temperature. Further, by a pressure-compensated variable displacement regulator of a variable displacement pump, the flow control valve is controlled to have irreducibly minimum pressure difference such that pressure on upstream side is slightly higher than the pressure on downstream side. Therefore, discharge pressure of the variable displacement pump can be suppressed to the irreducibly minimum value, and capacity of the variable displacement pump can be controlled to match the opening degree of the flow control valve.
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Citations
6 Claims
- 1. A system for controlling a hydraulic drive for a cooling fan in a cooling tower, comprising a hydraulic motor connected to the cooling fan, a variable displacement pump connected to said hydraulic motor via a hydraulic pressure supply line and driven by a motor, a flow control valve arranged in said hydraulic pressure supply line, a temperature detector for detecting supply water temperature in the cooling tower, a controller for controlling said flow control valve based on a difference between a temperature detected by said temperature detector and a preset temperature and a pressure-compensated variable displacement regulator for controlling capacity of the variable displacement pump to maintain irreducibly minimum pressure difference between pressure on upstream side and pressure on downstream side of the flow control valve in said hydraulic pressure supply line.
Specification