Heat Pipe Heat Exchanger Technology (HPHX) Overview

Q. How can heat pipe heat exchanger technology save your company money and increase profitability?

A. Heat pipe heat exchanger technology saves your firm in terms of its energy spend with: Higher recovery rates, lower pressure drops across both (or more) sides of the heat exchanger, and they are completely passive.

• Higher thermal energy recovery rates means greater heat transfer from the source to the sink

• Unlike traditional heat exchangers, heat pipe heat exchangers are not comprised of small channels that the energy streams must travel through in order to give up or gain their heat. Those small channels or paths can lead to significant pressure drops along with other maintenance issues. The overall heat pipe design will lead to significantly lower pressure drops than other heat exchanger technologies available today. Lower pressure drops can mean lower or no parasitic loads allowing for smaller pumps and/or fans which also mean lower operating costs. Many times where a heat pipe heat exchanger is added to a circuit, extra fan or pumping power is not required lowering much of the operating costs which would occur year over year.

• Unlike some classical “rotary” heat exchangers, Heat Pipe Heat Exchangers do not rely on an energy grabbing motor to move air or a liquid between the approaching and exiting ends of the heat exchanger. Many times, especially in the case of large air pre-heaters, these motors are quite large and require significant costs in energy usage.

 

Q. Why is heat-pipe heat exchanger technology a better choice than other heat recovery options?

A. Our Heat Pipe Heat Exchangers enjoy many advantages over those of traditional or classical style heat exchangers due to: Zero cross contamination, nearly total isothermal operation and high temperature application.

• The two incoming energy streams are completely separated by a solid wall, therefore eliminating the risk of cross-contamination. With no moving parts to wear out bearings or seals, a significantly more positive and better sealing process then becomes available.

• Isothermal operation assuring no “cold spots” or condensation traps as the length of each heat pipe remains a constant, continuous temperature.

• High temperature applications are possible due to the heat transport rates for heat pipes which are very high due to the latent heat of vaporization, and the thermal conductivities of the working fluids internal to the heat pipes.

 

Q. Why does a heat-pipe heat exchanger have lower life cycle costs than competing heat exchangers?

A. Life cycle costs will be lower as maintenance activities are less complex and time consuming as heat pipe heat exchanger technology offers a high particulate tolerance which will lead to lower fouling, intrinsic redundancy of the heat pipes, can also be inspected or cleaned in situ and will not suffer from metal fatigue or stresses which typically shorten competing heat exchanger life spans.

• Because there are no small channels to block and being capable of higher velocities with lower pressure drops, heat pipe heat exchangers have a lower propensity to fouling.

• Each heat pipe only has one point of connection at the partition plate (a.k.a. divider plate, tubesheet) within the heat exchanger meaning there will be less metal fatigue due to thermal stresses. This can be very significant in batch processes or variable thermal flows or in start-up situations where most typical heat exchangers must be staged or “slowly brought up to temperature” in order to alleviate thermal stresses.

• Life cycle costs include maintenance activities such as cleaning if required. Heat Pipe Heat Exchangers are designed with maintenance access panels to both inspect and/or easily clean the internals of the unit.

• As inspections and routine cleaning are a normal process of any piece of equipment, the same maintenance access panels will allow for in situ inspections or cleaning procedures.

• Should a heat pipe fail for any reason (hint: they do not wear out), energy will continue to be transferred at optimum performance due to the fact of having multiple heat pipes within the shared bundle(built in redundancy). For example, if there should be 500 heat pipes and one fails, the efficiency ratio would only drop .2% which means the heat exchanger would not be considered a failed unit.

 

Q. What kind of floor space does a heat pipe heat exchanger require and are they expandable?

A. From a space constraint viewpoint, heat pipe heat exchangers will typically offer a smaller foot print, are scalable in size and can be designed to optimize or fine tune “in the field”.

• When reviewing from an equal performance perspective, heat pipe heat exchanger technology will generally offer a smaller footprint.

• Heat pipe heat exchangers are completely scalable both horizontally and vertically and can be designed to fit into almost any space constraint.

• During the design process, future heat duty capacity can be allowed for by the addition of excess heat pipe connection points.

• Optimizing or fine tuning a unit can be performed quite simply by removing or adding heat pipes as required.