Heat-transfer fluids and heat pipes
Fluids and devices that move heat: thermal oils, molten salts, refrigerants, heat pipes and trucked heat stores.
Transport · Heat, motion and embodied energy · No. 65
- Transport
- Form: Heat
In 1833 a ship sailed 180 tonnes of ice from Boston to Calcutta, and over half of it survived the four-month voyage.
Chart: Illustration: Heat-transfer fluids and heat pipes
Where it comes from
Chart: Map of where it comes from
Heat moves by conduction, convection and radiation, so engineers match the carrier to the temperature: thermal oil up to 400 C, molten salt from about 290 to 565 C.
Three things to know
- A heat pipe conducts heat at an effective 10,000 to 100,000 W per metre per C, far beyond copper's 390, with no pump at all.
- A leaked 2 kg refrigerant charge with a GWP of 3,922 warms the climate as much as 7.8 tonnes of CO2.
- Passive ammonia heat pipes keep the permafrost frozen beneath 420 miles of elevated oil pipeline.
The journey
- 1 Heat sourceSolar field, furnace, chip or waste heat
- 2 CarrierOil, molten salt, refrigerant or heat pipe
- 3 TransportPumped loop, wick or trucked container
- 4 StorageInsulated tanks hold heat for hours
- 5 ReleaseHeat exchanger hands heat to its user