Heat Pipe Heat Exchanger

What are Heat Pipes and Heat Pipe Heat Exchangers

Heat Pipe Working Principle

Heat pipes are heat transfer devices that contain an operating fluid that is completely sealed in. The boiling and condensation of the operating fluid within the heat pipe enables very efficient heat transfer from a heat source to a heat sink.

The operating fluid gets heated up and boils in the evaporator section by picking up heat from the heat source.

The vapours of the operating fluid then condense in the condenser section by losing heat to the heat sink. The condensed liquid falls back into the evaporator. 

Evaporation, Condensation and the two-phase flow within the heat pipe happens when there is a temperature difference between the heat source and the heat sink. If the heat source and the sink are at the same temperature, the fluid inside the heat pipe stops moving. The fluid flow starts again as soon as there is a temperature difference between the heat source and the sink. This temperature difference is the only power source needed for the heat pipes to operate.

Heat Pipe Heat Exchanger Working Principle

Heat Pipe Heat Exchanger (HPHE) is a heat exchanger in which Heat Pipes are arranged in a specified grid format and boxed up such that the bottom section forms the Evaporator, and the top section forms the Condenser.

The hot fluid flows through the Evaporator section and the cold fluid flows through the Condenser section in counter or cross flow manner.

The Evaporator and Condenser sections are isolated from each other, ensuring no cross contamination between the hot and the cold fluids.

Advantages of Heat Pipe Heat Exchangers

Our HPHE Technology Provides

  • Multiple redundancy as each Heat Pipe operates independently. Failure of a heat pipe has very little impact on HPHE performance. 
    Conventional heat exchanger will need a shutdown and tube replacement in the event of a tube rupture

  • The design of the HPHE allows the heat pipes to expand freely and eliminates heat stress on the pipes.
    Heat stress in Shell & Tube or Fin Tube heat exchangers can cause the tubes to buckle

  • Heat transfer is not affected by pipe thickness allowing usage of thicker pipes with higher corrosion allowance.
    In Shell & Tube and Fin tube heat exchangers, higher tube thickness increases heat transfer resistance 

Heat pipes operate under isothermal conditions. This eliminates formation of cold or hot spots, allowing greater heat recovery.
With HPHE flue gases can be easily cooled to a temperature close to its dew point, allowing greater energy recovery from the flue gases. In conventional heat exchangers cold spot formation is an issue and can cause corrosion due to condensation in flue gases.

  • Heat pipes have a long life and requires very little maintenance. Maintenance and cleaning can be done in-situ. Uninstallation of the heat exchanger is not needed.
    Cleaning the tube bundles in Shell & Tube and Fin tube heat exchangers is not easy and most often the heat exchanger needs to be uninstalled.

  • Cross contamination of process fluids is not possible as the Evaporator and Condenser are isolated from each other. Failure/rupture of a heat pipe does not impact the process fluids. 
    In conventional heat exchangers tube rupture will cause process fluid cross contamination.

HPHE can be easily used to recover energy from High particulate/sooty flue gases, corrosive fluids, dirty liquids and other such challenging fluids. 

HPHE generally needs 20-30% lesser heat transfer area than a conventional heat exchanger.