Study Notes Quiz
The figure shows a tank filling with fluid at a variable rate, and an output regulated manually by an operator controlling a value.
Explain, with the aid of a control block diagram, the control process taking place that enables the operator to maintain a constant tank level, ‘h’ for varying rates of fluid flow input.
Note: fluid flow in will always be less than the maximum flow out with the valve full open.
For the automatic closed loop engine cooling control system shown in the figure:
(a) identify the signal paths A, B, and C;(3)
(b) describe the function of the comparitor;(2)
(c) name and describe the function of component D;(4)
(d) state a suitable device capable of producing a varying signal at T.(1)
Explain, with the aid of a diagram, the principle of a cascade control method for regulating the freshwater coolant temperature of a diesel engine.
(10)
(a) Sketch a block diagram of a split range control system, used to control the jacket water temperature of a main engine.(6)
(b) Describe the operation of this system.(4)
(a) Define EACH of the following terms:
(i) cascade control;(4)
(ii) split range control.(3)
(b) Describe possible problems associated with split range control used for the control of a main engine cooling system.(3)
On passage at full sea speed, a high jacket water temperature alarm goes off. The header tank is full, there are no leaks in the systems, both the HT and SW pumps are running and in good condition, however the temperature is continuing to rise.
(a) State the immediate course of action that should be taken, explaining why.(2)
(b) From the information on the supplied system diagram, shown in the figure below, describe THREE possible actions that may bring the plant back to within normal operating parameters.(8)
(a) Identify components A, B, C, D, E, F, G and H shown in the figure. (8)
(b) Explain the difference between a strainer and a filter in a hydraulic circuit.
(2)
(a) Explain the term failsafe in a control system, stating TWO examples where this term is applied.(4)
(b) Explain the term failset in a control system, stating TWO examples where this term is applied.(4)
(c) State what is meant by a 4:3 control valve.(2)