Home >> Hobbies >> Other Hobbies

How to Design a Double Pipe Heat Exchanger

A double pipe heat exchanger transfers heat from one medium to another, usually in space heaters, refrigeration or power plants. A double pipe heat exchanger contains either one small pipe within a larger pipe or several small pipes within a large pipe. The cool water passes through the space between the inside of the large pipe and outside of the small pipe, while the heated water passes though the inner pipe. Design your own double pipe heat exchanger to save money and exercise your creativity.

Things You'll Need

Sketch pad
Pen

Instructions

- 1
  Construct your pipes from sheet metal, steel or cast iron. Steel is commonly used for heat exchangers, either galvanized or aluminized. This keeps the steel from corroding or rusting. Cast iron is another choice as it retains heat for a long time; however, it may take longer to heat cast iron than it would to heat steel.
- 2
  Design smooth or finned tubes. If your heat exchanger is going to be accepting low-pressure fluid, go with the smooth tubes since they stay heated. The fins on the finned tube can cause a drop in pressure with low-pressure fluids.
- 3
  Design a two-tube unit or mini-tube unit. Two-tube units contain one tube within a larger tube. A single pass unit causes the fluid to run the length of the pipe. A multipass unit causes cool and hot fluids to pass each other through parallel circuits numerous times for more efficient heat exchange. A mini tube unit consists of a group of small tubes placed inside of a larger tube.
- 4
  Calculate the heat transfer surface area required for your double pipe heat exchanger, using the heat transfer coefficient formula. The answer to this formula determines the length required for your pipe.

Other Hobbies