What is Heat Pipe?

Heat pipes are Heat transfer devices. They are Hollow cylindrical pipes filled with a small amount of fluid that evaporates to produce heat. This heat is then rejected from another end for its application on industrial processes. For example, it is used in Air Conditioning and Refrigeration application.

Heat pipe working principle:

Heat pipe is generally self-heat recovery devices that are used to transfer heat from one end (heat injection) to another (destination) with minimum temperature differences and also to pass the heat across internal surface. Many terms have to be taken into consideration while choosing a pipe for application on industrial devices. They are manufactured in different shapes such as round or flat shapes.

Function and Design of Heat Pipe:

They is enclosed under vacuum with a sufficient, preset amount of working fluid. At initial state, the working water is contained inside the wick lined structure that lines the inside area of the heat pipe.
When a heat injection, an electronic component, generates heat for input, the fluid/water inside the heat pipe evaporates in vapor which is known as the evaporator section or bottom end.
The water vapor immediately spreads and goes to the other end (condenser) of the heat pipe, hence using the pressure generated by the minimum temperature difference.

At the opposite end known as the condenser part, the working fluid/water rejects out its latent heat, which is rejected or produced to an external device i.e. heat sink.

The water then again returns to liquid/fluid form, and the wick structure inside the heat pipe relatively or passively pumps the fluid/water in reverse direction to the evaporator section by using capillary force.

By using this liquid and vapor phases, heat transport mechanism becomes extremely fluent and efficient. Because of heat pipes closed loop design, heat pipes works continuously and passively, gaining a very reliable and passive part in your thermal management system.

Types of Heat Pipes:

• Hot Gas to Air
• Hot Gas to liquid
• Heat Pipe Panel Cooler
• Heat Pipe Dehumidifier

Hot Gas to Air Heat Pipe Exchanger:

The Hot Gas-Air Heat Pipe exchangers consists of different types of tubular gravity, that are supported with finned Heat Pipes and are regulated in a staggered pitch; depending upon the application process. One of the advantages of Heat Pipe Exchanger is its ability to function without cross contamination of media between the two streams.

Hot Gas to Liquid Heat Pipe Exchanger :

The Hot Gas to Liquid heat pipe exchanger consists of Air to Air unit and the only difference is that liquid/water insulated tank is provided to contain media at the condensation section in order to preheat liquid / water.

Maniks heat pipe exchanger is capable to recover 85% of exhausted thermal energy which is otherwise wasted in the atmosphere.
With special materials used for construction of the tube, the heat exchanger may be designed to extend up to the range 427℃ to 482℃.

Heat Pipe Panel Cooler (HPPC):

Electrical and electronics operated control panels are made air tight in order to protect our costly electronic and electrical operated devices from dust. The parts inside the electronic devices get overheated which thus leads to failure or mal-function. So the Maniks Control panels coolers are able to extract overheat from inside panel without disturbing the inside environment of the panel.

Heat Pipe Dehumidifier (HPD):

In an air conditioning and refrigeration system, the moisture is condensed out, when the air becomes colder and colder. The heat pipe is customized to have one cold outgoing stream and one warm incoming stream. Therefore by transmitting the heat, from warm air to the cooled outgoing stream supply air, the heat pipe exchangers are responsible to create double effect of pre-cooling the working air, before it goes to the evaporator section and finally re-heating it immediately. This lowers the heating load, cooling load, and evaporating temperature.

Thus Heat pipe Dehumidifier results in effective energy savings. Typically, for each 1℃ rise in the thermostat setting, there is 3% savings in electricity/energy cost. In addition to this, the pre-cooling effect of heat pipe exchangers allows the use of a smaller compressor which also increases the condenser life and capacity.

Heat Pipe Applications:

• Compact Electronics Enclosures
• Aerospace
• Medical
• Consumer Electronics
• HVAC

1) Compact Electronics Enclosures:

Heat Pipe Exchanger provide highly-efficient, compact cooling design for electronic cabinets and enclosures, and it also meets today’s growing demand for thermal power requirements, due to greater miniaturization.

2) Aerospace:

Heat pipe is a very attractive element in the area of aerospace for spacecraft cooling and temperature stabilization, due to their low weight, zero maintenance cost, and reliable functionality. Maintaining isothermal structures in aerospace is a crucial task with respect to obituary astronomy practices under the adverse solar heating.

3)Medical:

Passive thermal applications (Heat pipes) offer a valuable advantages in medical/hospital devices in terms of saving space, minimizing weight, and reduction of maintenance costs, as they result in less environmental effects as compare to other cooling systems that depend various technologies such as pumped liquids etc. As there is a constant increase in electronics and electrical operated devices and their need of computing power results increased heat to be rejected (wasted), and also because of miniaturization is minimizing the required amount of space for thermal management systems, new thermal technologies today like heat exchangers play a very major role in the tomorrow’s manufactured medical devices.

4) Consumer Electronics:

Heat pipes heat exchangers are mostly applicable in many day to day consumer specific electronic devices such as Power supplies, Laptop and desktop computers, Computer microprocessors, Audio amplifier components, Computer gaming equipment.

5)HVAC:

A specially manufactured passive reliable heat recovery HVAC heat pipe will provide you an affordable and effective power recovery system for the hot summer days and your cold winter months continued throughout the year. It also lowers your energy bills and also provides you a rapid return on your initial investment cost.

Heat Pipe Features And Benefits:
• Tube material: Copper/ Aluminum
• Wick structures:
o Grooved– Low Cost, does not work well against gravity
o Wire Mesh – Most common method
o Sintered – Highest performance and cost
• High thermal conductivity
• Light weight
• Fast thermal response
Heat pipe Advantages:
• Passive Operation
• Long Life
• Zero cross contamination since streams of source and sink are physically separated
• Minimum Maintenance
• Compact Size
• Practically zero back pressure

MANIKS – Leading Manufacturers of Heat Pipes:

Hello, thank you for joining MANIKS for this lesson on heat pipe basics. Among many different brands MANIKS also manufactures Heat pipes on a wide range with its outstanding noteworthy benefits. MANIKS Heat Pipes include Passive operation and Reliability due to its looped close structure, Zero operating cost, Enhanced condenser life, no cross contamination between the source and heat sink, minimum maintenance cost, compact size of pipe and many more. Maniks give a very prompt service even after sales as our technicians are highly skilled and have a very vast knowledge of not only our own manufactured products, as well as the entire working of a system. This helps us in quick fault-finding at customer’s site.