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Thermal Fluid Design

Summary

Conducting numerical analysis of flow property, we judge appropriate structure by numerical analysis of structure.  With extensive experience, we make decision if diffusion bonding can be applied. Repeat numerical analysis and consideration of form for a product which is difficult to form.

 

Micro Heat Exchanger

Summary

What is Micro Channel Heat Exchanger

Micro heat exchanger has micro channels which have 1μm~1mm cross-section surface of each flow. It can improve heat transfer density dramatically.
Heat exchange efficiency of micro heat exchanger is
excellent, so that conventional heat exchanger can be downsized. In order to improve efficiency, conventional heat exchanger uses turbulent fluid.
On the other hand, fluid of micro channel is laminar and very efficient, so that pressure loss is held down, system can be downsized, expensive refrigerant can be less, which can contribute to energy saving. Downsizing heat exchanger contributes to cost saving extremely since facility can be
downsized and supporting structure is not necessary.

Heat exchanger

A *heat exchanger* is a part to transfer heat from one fluid to another.
With common heat exchanger, the medium is separated by the solid wall, and heat is transferred through the wall. In order to improve the efficiency of a heat exchanger, area of heat transfer is increased by improving fin configuration or increasing the number of halls.

Technical term

  • Pressure loss
    When fluid runs in tubes or along walls, the pressure is decreased by friction resistance of walls.
  • Overall heat transfer
    A measure of the overall ability of heat transfer between the medium in a heat exchanger.

Micro Channel Effect

 

Heat sink

Summary

About Heat sink

Heat sink is a piece to release heat from the surface of mechanical or electronic parts producing heat using heat transfer or heat conduction.
The way of heat transfer varies according to the amount of heat production per unit area. In case heat production is large, fluid is used to remove heat. Generally, The larger surface area becomes, the larger the amount of heat production is.

Micro Channel Heat Sink

Micro channel heat sink is a heat sink with each flow has cross-cut section of 1μm~1mm. Heat transfer density can be improved considerably.  A conventional heat sink can ne downsized since a micro heat sink can lower heat resistance.

Technical term

Heat Transfer

It is to convey heat in any one or combination of conduction, convection, radiation.

  • Heat Conductivity
    Heat conductivity is the transfer of heat within material from regions of higher temperature to regions of lower temperature without change of form or movement.
    This is a mechanical property which is unique to material.
  • Coefficient of Thermal Expansion(CTE)
    Coefficient of thermal expansion is the ratio of change of size or volume of material due to the rise of temperature. This is a mechanical property which is unique to material.
  • Thermal Resistance
    Thermal resistance shows how much material resists heat transfer. Unit is K/W.

Technical term

一流路-(1path)-

One Path Fluid Flow

One path fluid flow is a common structure of flows for heat exchanger. It is usually manufactured by the combination of mechanical process and brazing.  Making a diameter of the flow small increases pressure loss, and making a diameter of the flow large decreases performance.  Temperature of fluid rises towards the exit, which causes temperature distribution.

並列流路(マイクロチャンネル)-

Parallel Flow (Micro Channel Flow)

Parallel flow is a structure of micro flows placed in parallel.  Even though the diameter of each flow is small, pressure loss is contained since many flows are placed in parallel. Compared to “one path flow”, temperature distribution is controlled.

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