Browse Prior Art Database

Endothermic Cooling Cartridge

IP.com Disclosure Number: IPCOM000114228D
Original Publication Date: 1994-Nov-01
Included in the Prior Art Database: 2005-Mar-28
Document File: 6 page(s) / 223K

Publishing Venue

IBM

Related People

Anderson, TM: AUTHOR [+3]

Abstract

A method for integrating a transient endothermic cooling capability into conventional cold plate or heat sink structures is disclosed. The concept provides a means for activating the cooler without external controls while still permitting the use of external controls should they be required. The field replaceable cooler provides for visual detection of whether or not the cooling capability of the device has been discharged.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 34% of the total text.

Endothermic Cooling Cartridge

      A method for integrating a transient endothermic cooling
capability into conventional cold plate or heat sink structures is
disclosed.  The concept provides a means for activating the cooler
without external controls while still permitting the use of external
controls should they be required.  The field replaceable cooler
provides for visual detection of whether or not the cooling
capability of the device has been discharged.

      The vessel (101) for an Endothermic Cooling Cartridge (ECC) is
a metal or other thermally conductive canister.  This canister is
likely to be round in cross section, but may be square, rectangular
or any other suitable shape.  Contained by the canister are volumes
of a solute (102) and solvent (103), which are separated by a
frangible barrier (104).  Also in the canister is a trigger mechanism
(105) that is armed to rupture the barrier when the canister
temperature exceeds a preset value.  As described in the following,
however, this trigger is also capable of being remotely activated,
either by an independent control system or by user override.  The
solute is typically a salt or mixture of salts.  The total solubility
of certain salt mixtures can exceed the solubility of the individual
components of the mixture, and an attendant enhancement in cooling
performance is thereby realized.  The solute is typically water or an
alcohol.  Although the reaction generally absorbs more heat when the
solvent is water, the use of alcohol can eliminate concern regarding
freezing of the solvent (e.g., during shipping) and the potential for
freeze related damage to the ECC.  Independent compounds are also
contained by the separate solute and solvent compartments of the ECC
which are clear until mixed.  When the barrier is broken these
compounds are mixed and react to color the solution.  A view port
(106) is provided through the canister wall to permit visual
detection of this coloration, and hence detection of whether or not
the canister has been previously activated.

      In some cases a thermal buffer (107), as described in (*), may
be mixed with the solvent to provide isothermal cooling.  The thermal
buffer is simply a fluid which functions as a phase change thermal
storage media.  Upon activation of the ECC, the cartridge temperature
will fall to the freezing temperature of the buffer media, after
which the buffer media will begin to freeze.  In this way, any
endothermic heat absorption in excess of that needed to keep up with
heat input to the system is stored by phase change of the buffer
media and the ECC temperature is held constant.  When salt is totally
dissolved or the solubility limit is reached, the ECC will continue
to
provide constant temperature cooling as the thermal buffer media
melts.

      The desired trigger mechanism can be achieved in many ways by
various combinations of a few basic elements.  Several suitable
triggers are illustrate...