Double pipe heat exchanger fouling compensation

A heat exchanging system, comprising:

• a counter flow double pipe heat exchanger (DPHE) configured to perform a heat exchanging process between a hot fluid in a hot fluid pipe and a cold fluid in a cold fluid pipe;
• and
• a proportional-integral-derivative (PID) controller configured to:
• receive a temperature error between a reference temperature and a temperature at an outlet of the hot fluid pipe of the counter flow DPHE, and
• output a cold fluid mass flow rate for the cold fluid in the cold fluid pipe of the counter flow DPHE based on the received temperature error,
• wherein the temperature error is controller within a predefined range by utilizing parameters of the PID controller that are set by using a harmony search algorithm (HSA) to obtain a minimization of a cost function.

A method of controlling a counter flow double pipe heat exchanger (DPHE) that includes a hot fluid pipe and a cold fluid pipe, the method comprising:

• determining a temperature error between a reference temperature and a temperature at an outlet of the hot fluid pipe of the counter flow DPHE;
• determining a change rate of the temperature error;
• determining a cold fluid mass flow rate from an output of a fuzzy logic controller based on the temperature error and the change rate of the temperature error being input to the fuzzy logic controller, the cold fluid mass flow rate being used for a cold fluid in the cold fluid pipe of the counter flow DPHE;
• and
• controlling the temperature within a predefined range by utilizing parameters of the fuzzy logic controller that are set based on a minimization of a cost function.

A heat exchanging system, comprising:

• a counter flow double pipe heat exchanger (DPHE) configured to perform a heat exchanging process between a hot fluid in a hot fluid pipe and a cold fluid in a cold fluid pipe;
• and
• a fuzzy logic controller configured to:
• receive (i) a temperature error between a reference temperature and a temperature at an outlet of the hot fluid pipe of the counter flow DPHE and (ii) a change rate of the temperature error, and
• output a cold fluid mass flow rate for the cold fluid in the cold fluid pipe of the counter flow DPHE,
• wherein the temperature error is controlled within a predefined range by utilizing parameters of the fuzzy logic controller that are set based on a minimization of a cost function.