University Of Maine At Fort Kent Operations And Supply Chain Management Assignment Help - I. M. Appelpolscher

Question - I. M. Appelpolscher, supervisor of the process control group of the Ideal Gas Company, has installed
a 25 x 40 x 5-ft swimming poe1 in his backyard. The poo1 contains level and temperature sensors
used with feedback controllers to maintain the pool level and temperature at desired values.
Appelpolscher is satisfied with the Level control system, but he feels that the addition of one or more
feedforward controllers would help maintain the pool temperature more nearly constant. As a new
member of the process control group, you have been selected to check Appelpolscher’s mathematical
analysis and to give your advice. The following information may or may not be pertinent to your
analysis:
(i) Appelpolscher is particular about cle ...Read More anliness and thus has a high-capacity pump that continually
re-circulates the water through an activated charcoal filter.
(ii) The poo1 is equipped with a natural gas-flied heater that adds heat to the pool at a rate Q(i) that is
directly proportional to the output signal from the controller pQ).
(iii) There is a leak in the pool, which Appelpolscher has determined is constant equal to F (volumetric
flow rate). The liquid level control system adds water from the city supply system to maintain the level
in the pool exactly at the specified level. The temperature of the water in the city system is Tw, a
variable.
(iv) A significant amount of heat is lost by conduction to the surrounding ground, which has a
constant, year-round temperature T. Experimental tests by Appelpolscher showed that essentially all
of the temperature drop between the poo1 and the ground occurred across the homogeneous layer of
gravel that surrounded his pool. The gravel thickness is ?x,, and the overall thermal conductivity is
kG.
(v) The main challenge to Appelpalscher’s modeling ability was the heat loss term accounting for
convection, conduction, radiation, and evaporation to the atmosphere. He determined that the heat
losses per area of open water could be represented by
Losses = U(Tp – T0)
whore
Tp = temperature of pool
Tn= temperature of (he air1 a variable
U = overall heat transfer coefficient
Appelpolscher’s detailed model included radiation losses and heat generation due to added
chemicals, but he determined that these terms were negligible.
(a) Draw a schematic diagram for the pool and all control equipment. Show all inputs and outputs.
Including all disturbance variables.
(b) What additional variable(s) would have to be measured to add feedforward control to the existing
pool temperature feedback controller?
(c) Write a steady-state energy balance. How can you determine which of the disturbance variables
you listed in part (a) are most/least likely to be important?
(d) What recommendations concerning the prospects of adding feedforward control would you make
to Appelpolscher? ...Read Less

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