Chicago 4-11 Alarm fire, 11-15-13 (pt 3)

1. Based on Flow Arrangement

• Parallel Flow (Co-current Flow):

  • Both fluids flow in the same direction.

  • Temperature difference is highest at the inlet and decreases along the length.

• Counter Flow (Counter-current Flow):

  • Fluids flow in opposite directions.

  • Maintains a more uniform temperature difference, leading to higher efficiency.

• Cross Flow:

  • Fluids flow perpendicular to each other.

  • Commonly used in air-cooled heat exchangers.

    2. Based on Construction and Design

    • Shell and Tube Heat Exchanger:

      • Consists of a series of tubes enclosed in a shell.

      • One fluid flows through the tubes, and the other flows outside the tubes within the shell.

      • Suitable for high-pressure and high-temperature applications.

    • Plate Heat Exchanger:

      • Uses thin, corrugated plates stacked together to create channels for fluid flow.

      • Compact design with high heat transfer efficiency.

      • Ideal for low to medium-pressure applications.

    • Plate and Frame Heat Exchanger:

      • A type of plate heat exchanger with a frame to hold the plates together.

      • Allows for easy cleaning and maintenance.

    • Plate-Fin Heat Exchanger:

      • Uses fins sandwiched between plates to increase surface area for heat transfer.

      • Common in aerospace and cryogenic applications.

    • Spiral Heat Exchanger:

      • Consists of two spiral channels wound around a central core.

      • Compact and efficient for handling viscous fluids or slurries.

    • Double Pipe (or Hairpin) Heat Exchanger:

      • Simplest design with one pipe inside another.

      • Suitable for small-scale applications or high-pressure scenarios.

        3. Based on Heat Transfer Mechanism

        • Direct Contact Heat Exchanger:

          • Fluids come into direct contact with each other.

          • Example: Cooling towers.

        • Indirect Contact Heat Exchanger:

          • Fluids are separated by a solid barrier (e.g., tubes or plates).

          • Example: Shell and tube, plate heat exchangers.

        • Regenerative Heat Exchanger:

          • Uses a heat storage medium to transfer heat between fluids.

          • Example: Rotary regenerators or fixed-matrix regenerators.

            4. Based on Application

            • Air Cooled Heat Exchanger:

              • Uses air as the cooling medium.

              • Common in power plants and refineries.

            • Liquid Cooled Heat Exchanger:

              • Uses liquid (e.g., water or oil) as the cooling medium.

            • Condensers:

              • Converts vapor into liquid by removing heat.

            • Evaporators:

              • Converts liquid into vapor by adding heat.

            • Boilers:

              • Generates steam by heating water.

                5. Based on Phase Change

                • Single-Phase Heat Exchanger:

                  • Both fluids remain in the same phase (liquid or gas) throughout the process.

                • Two-Phase Heat Exchanger:

                  • Involves a phase change (e.g., condensation or evaporation) in one or both fluids.