Troubleshooter
Heat balance
Cooling
A directional control valve install in the system to direct oil from the return line through the cooler to the tank. The heat return to the tank is partly remove to the outside through the walls of the tank but is too insignificant to provide effective cooling.
This valve is control from working pressure side. In figure the valve is in neutral position. When working pressure is on the right side the valve switch to neutral position and hot oil from low pressure side respective left side is directed to the tank via pressure relief valve. The setting of the valve is specified in the instruction or maker manual.
The operating principle is the same if working pressure is at the left hand side.
Heat balance for a hydraulic system
Heat create in the hydraulic circuit by pumps, valves, actuators and pipes is transport by the fluid to tank. The heat return to the tank is partly remove to the outside through the walls of the tank. If the radiation surfaces are not sufficient, additional heat exchanger (coolers) have to include in the design of the system, so that the system and fluid does not overheat.
Size and nature of heating and cooling system for a hydraulic installation depends on system demands, its precision and life. All these attributes give the type of being use. In majority of cases it is necessary to calculate a heat balance for the hydraulic system.
Continuing develops hydraulic system to conquer new lifting capacity and to become reliable for any application, demands a constant fluid temperature. This has to be kept in mind when designing hydraulic system.
