Static / Dynamic Characteristics Of Centrifugal Compressor Lubricating Oil Temperature Control Valve

In hydraulic systems where the power consumption is large, losses components will lead to undesirably elevated. A highly elevated oil temperature is undesirable since the oil may deteriorate and mechanical and lubrication problems may arise if the viscosity becomes too low. In attempting to control the oil temperature, hydraulic systems are often equipped with a self-operating temperature controlling valve (SOTCV) controlled exchanger. The possibility of simulating fluid and component temperatures in oil temperature-control systems is important to avoid malfunctions and optimize the equipment and will lead to a better understanding of the thermal considerations that must be taken in the SOTCV design.The self-operating temperature controlling valve (SOTCV) is fed by two fluid pipes, supplying hot and cool fluid. The device incorporates a valve with mechanical feed-back for mixing hot and cool fluid to a desired temperature. The mixing fluid flows past a temperature sensitive actuator consisting of a phase-change wax material in a brass enclosure, making the position of actuator piston a function of the actuator temperature. The actuator acts on the spool, thus compensating for discrepancies in the mixing fluid temperature. Possible over-shoot in dynamic response is damped when the mixed fluid flows through volumes before leaving the valve.The study includes the understanding of the governing principles of the regulator, stationary as well as dynamical, and involves fluid-flow, heat transfer, thermodynamic and control principle considerations. Emphasis is put on both the stationary characteristics and the dynamic performance.A computer model of the mixing valve based on simulink is developed in order to calculate temperature, and flow at several locations in the valve as a function of time. The temperature depends on the thermodynamic change of the fluid due to the heat transfer to the surroundings and the energy transport in the fluid. The simulations are combined with the literature.From computer simulations, the dynamic characteristics are analyzed. Optimization is used to study performance parameters. The outcome is used to ensure the accuracy of the methods used in the thermodynamic calculations.