Installing Temperature And Composition Controllers

Installing temperature and composition controllers is somewhat more involved than installing level and flow controllers because of three issues:

1. We need to include additional dynamic elements in the loop. Temperature and composition measurements have significant inherent dynamic lags and deadtimes.

Figure 7.19 (a) Flow controller setup; (b) filtering.

These should be incorporated in the control loop. This is necessary so that we use realistic controller tuning constants and do not predict dynamic performance that is better than reality.

2. The tuning of temperature and composition controllers is more involved than simply using heuristics as is done for flow and level controllers. Some convenient and

Figure 7.20 Controller faceplates.

effective tuning procedure is required. One of the best methods is to run a relay -feedback test to find the ultimate gain and ultimate frequency, and then use the conservative Tyreus-Luyben tuning settings.

3. The appropriate location for the temperature or composition sensor may not be obvious. Some method for making a good selection must be used. As discussed

Select rewind snapshot:

Description

Sim Time

Date & Time

| Converged

Run Number |

HI Initialization Run

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