Original Publication Date: 2005-May-23
Included in the Prior Art Database: 2005-May-23
This disclosure describes a plenum that delivers fresh cooling air to a grid of multiple locations, using nested inlet and exhaust ducts that naturally balance the flow volumes.
Disclosed is a cooling plenum that delivers fresh, non-preheated ambient air, to components in parallel on an electronic circuit board. This new disclosure provides a means that can volumetrically balance the inlet and exhaust requirements of this parallel cooling method, lowering impedance to airflow, and allowing better cooling balance to the board components. It also allows for the possibility to simplify the construction, and reduce the cost, weight, and volume of the plenum.
This impingement plenum provides the main function of distributed cooling in a densely packed area while optimizing several parameters, including: a) It is volumetrically efficient to nest the inlet and outlet portions with cross sectional areas naturally tapering with the required flow changes. b) Air flow impedance is minimized due to the tapering inlet and exhaust sections (maximum cross section is provided at the highest flow locations). c) Air flow can be easily balanced by adjusting slot sizes.
This can be used to accommodate different power requirements of the component being cooled (low power, high power, ...), changing configurations, or different flow boundary conditions. d) The component parts of this plenum are simple to manufacture.
e) The frame of the plenum can be bolted to the electronic card, separately from the inlet / exhaust channel piece of the plenum. The frame provides the stiffener function for the card while the removable plenum facilitates access to the card for rework or testing. The space between the plenum frame and internals can also be used to provide two extra exhaust columns. f) The plenum frame itself can have openings to provide cooling to different components (bus bars for example).
Figure 1 shows the general concept of fresh air delivered to each component and being exhausted.
Figure 2 shows an embodiment where inlet air is available on the top and front face of the plenum. Fresh air flows to the inlet columns and through the inlet slots onto the center of the heatsinks. Air then splits and goes out each side of the heatsink to an exhaust column, and then out the bottom to a blower...