Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Tank Control Logic Problem Narrative A storage tank system for a
Transcript
Tank Control Logic Problem Narrative A storage tank system for a pancake syrup manufacturing company is shown in Figure 1. The control logic allows a volume of corn syrup solution to be preheated to a specified temperature to achieve the proper viscosity prior to being sent to a mixing vat where ingredients such as sugar, flavoring, preservative, and coloring are added. Level and temperature sensors in the tank and the flow sensor provide the inputs for the logic. System Operation and Requirements The tank holds the corn syrup for use in a pancake syrup manufacturing process. In preparation for mixing, the temperature of the corn syrup when released from the tank into a mixing vat must be at a specified value for proper viscosity to produce required flow characteristics. This temperature can be selected via a keypad input. The control logic maintains the temperature at this value by turning a heater on and off. The analog output from the temperature transducer (Tanalog) is converted to an 8-bit binary code by an A/D converted and then to an 8-bit BCD code. A temperature controller detects when temperature falls below the specified value and turns the heater on. When the temperature reaches the specified value, the heater is turned off. The level sensors produce a HIGH when the corn syrup is at or above the minimum or at the maximum level. The valve control logic detects when the maximum level (Lmax) or minimum level (Lmin) has been reached and when solution is flowing into the tank (Finlet). Based on these inputs, the control logic opens or closes each valve (Vinlet and Voutlet). New corn syrup can be added to the tank via the inlet valve only when the minimum level is reached. Once the inlet valve is opened, the level in the tank must reach the maximum point before the inlet valve is closed. Also, once the outlet valve is opened, the level must reached the minimum point before the outlet valve is closed. New syrup is always cooler than the syrup in the tank. Syrup cannot be released from the tank while it is being filled or its temperature is below the specified value. Problems / Questions to Answer: A. Inlet Valve Control 1. Enumerate the conditions for which the inlet valve is open, allowing the tank to fill: _____________________________________________________________________ _____________________________________________________________________ 2. Fill up the truth table with specified column labels. LMAX LMIN FINLET VINLET 3. In problem 2, are there conditions which cannot occur? What are they? _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ 4. Using K-Map, give the optimized Boolean equation: __________________________ B. Outlet Valve Control 5. Enumerate the conditions for which the outlet valve is open, allowing the tank to drain:________________________________________________________________ _____________________________________________________________________ 6. Draw the corresponding truth table for all possible conditions. 7. How many inputs are there in the truth table for outlet valve control. What are they? ____ ______________________________________________________________ 8. Under how many input conditions is the outlet valve open? _____________________ 9. In problem 6, are there conditions which cannot occur? What are they? _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ 10. Using K-Map, give the optimized Boolean equation: __________________________ 11. For simulation purposes, draw and label the logic diagram inside the black box below for the partial monitoring and control logic. +VCC VINLET VOUTLET T C. T L C 12. The temperature control logic (TCL) may be implemented using the block diagram below. Focusing only on the 8-bit BCD measured and specified temperature as inputs, design the C.L. circuit to realize the TLC. 8-bit binary code A/D TANALOG (Analog-to-digital) Converter 8 8-bit BCD for measured temperature Binary-toBCD Converter TCL 8 T 8 8-bit BCD for specified temperature Figure 1. Tank with level and temperature sensors and controls Corn syrup MONITORING & CONTROL LOGIC INLET VALVE FINLET FLOW SENSOR VINLET LMAX T LMIN VOUTLET TANALOG LEVEL SENSORS TEMPERATURE TRANSDUCER HEATER To mixing vat OUTLET VALVE
