This standard specifies the design guidelines for cold plates used in electronic equipment. This standard applies to cold plates made of various aluminum and aluminum alloys used in electronic equipment. GB/T 15428-1995 Design guidelines for cold plates for electronic equipment GB/T15428-1995 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Cold plate design guideline for electranic equipment
Cold plate design guideline for electranic equipment1 Subject content and scope of application
This standard specifies the design guideline for cold plates used in electronic equipment. This standard applies to cold plates made of various aluminum and aluminum alloys used in electronic equipment. 2 Reference standards
GB3190 Chemical composition of aluminum and aluminum alloy processed products GB3880 Aluminum and aluminum alloy plates
GB/T12993 Evaluation of thermal performance of electronic equipment
3 Terminology
3-1 Cold plate
Refers to a single-fluid (air, water or other coolant) paint-tight heat exchanger. 3.2 Air cooling cold plate (air cooling cold plate) uses air as the medium to remove the heat consumed by electronic equipment through convection with the cold plate. GB/T 15428 -1995
3.3 Liquid cooling cold plate uses water or other organic coolants such as fluorocarbons as the medium to remove the heat consumed by electronic equipment through convection with the cold plate. 3.4 Heat storage cold plate uses the coolant to absorb the heat of fusion during the phase change (solid to liquid) process to remove the heat consumed by electronic equipment. 3.5 Heat pipe cold plate uses a device composed of a heat pipe with high heat transfer and a cold plate to remove the heat consumed by electronic equipment. 4 Basic design requirements
4.1. The cold plate should be designed based on comprehensive factors such as the distribution of heat sources of electronic components (concentrated, uniform, non-uniform), heat flux density, allowable temperature, allowable pressure drop of the cold plate channel, and working environment conditions of the cold plate. 4.2 The cold plate should be calculated for heat exchange and structural strength. 4.3 The cold plate usually includes end caps, cover plates, fins and bottom plates, which are made by vacuum welding, salt bath welding or other welding methods. The typical cold plate structure is shown in Figure 1.
Approved by the State Administration of Technical Supervision on January 5, 1995 and implemented on August 1, 1995
GB/T15428-1995
Figure 1 Typical cold plate structure
4.4 The materials used to make the cold plate (including fins, cover plates and end caps) shall comply with the provisions of GB3880 and GB3190. 4.5 Coolant in the cold plate channel
a. Air-cooled cold plates generally use air at room temperature (25) under one atmosphere as the coolant. b. Liquid-cooled cold plates generally use water at room temperature (25C) under one atmosphere as the coolant. For some cold plates with special requirements, other fluids (such as fluorocarbons FC) can be used as the coolant of the cold plate. The heat storage cold plate uses saturated hydrocarbons (C.H2u12) as phase change materials. c.
The coolant supplied by the manufacturer shall be inspected and qualified by the relevant departments, and provide detailed technical performance parameters. 4.6 The cold plate shall be tested for thermal performance in accordance with the provisions of GB/I12993. 4.7 The production and manufacturing of cold plates shall be inspected, and qualified products can be put into use (or tested). 5 Heat exchange calculation of cold plates
5.1 Uniform temperature cold plate
5.1.1 The heat exchange calculation of air-cooled or liquid-cooled cold plates shall be carried out according to the convection heat transfer equation and the energy balance equation. 5.1.1.1 The heat dissipated by the electronic components installed on the cold plate is transferred to the cold plate by heat conduction and convection. The convection heat transfer process is:
Q.=hA.N.*7a
Where: Q is the heat consumption of the electrical equipment, W;
is the convection heat transfer coefficient, W/mK
A is the total heat transfer area involved in convection, m\, A. The logarithmic mean temperature difference,
%" is the total efficiency of the cold plate.
Ar is the surface area of ​​the fin, m;
is the efficiency of the auxiliary plate.
5.1.1-2 The heat absorbed by the coolant in the cold plate channel under the cycle is: Q. - qm - cp - (ta t))
Formula:-
-heat absorbed by coolant, W;
mass flow rate of coolant, kg/s;
specific heat of coolant at constant pressure, J/(kB·K)
-coolant outlet temperature, °C,
fi—-coolant inlet temperature, °C. GB/T15428—1995
(Physical parameters of various coolants, see Appendix A (Supplement)) 5.1.2 When the heat transferred by the cold plate is equal to the heat absorbed by the coolant When the phase is in equilibrium (Formula (1) is equal to Formula (2)), the average temperature ta of the cold plate surface is
wherein, NTU-number of heat transfer units,
NTU=hn·A/m·c,
.——allowable surface temperature of the cold plate (℃). Ignoring the contact thermal resistance between the electronic components and the cold plate, Ct. is the shell temperature of the electronic components to be excavated.
5.1.3 The pressure drop △P of the coolant in the cold plate channel should be lower than the allowable pressure drop [△P). The calculation formula of △P is: [(k +1 - 0) + 2(e -
(1 - - .) )
Wherein: G-
Mass flow rate per unit area, kg/s·m, acceleration of gravity.m/s;
, P2-density of coolant at inlet and outlet temperatures of coolant, kg/mAverage density of coolant,
Pm=(p1+p2)/2,kg/m;
Ratio of cross-sectional area of ​​cold plate channel to cross-sectional area of ​​cold plate (see Appendix B), DA/A3
A,-—Cross-sectional area of ​​cold plate channel, m; At—Cross-sectional area of ​​cold plate, m\
K. K. are the inlet and outlet loss coefficients of coolant (see C2 and C3 in Appendix C), respectively, and friction coefficient (see C1 in Appendix C).
5-1.4The convective heat transfer coefficient of cold plate is related to the shape of fins, structural form, flow rate and physical properties of coolant, and can generally be calculated as follows:
h - jGc,-Pr--
......
coefficient, related to the storage number (Re) of various channels and fluids composed of the auxiliary sheet (see C1 in Appendix C); where ·
Prandtl number (see Appendix A).
5.2 The heat transfer calculation of the non-uniform temperature plate can be analyzed and calculated by the finite difference method or the finite element method. (5)
5.3 The heat transfer calculation of the heat storage cold plate is mainly to determine the mass of the phase change material required to take away the heat consumed by the electronic components. The general calculation formula is:
where: m-
The mass of the phase change material, kr!
GB/T 15428--1995
PThe heat dissipated by the electronic components, W,
--The temperature control cycle required by the electronic equipment, s; H——The melting heat of the phase change material J/kg.
6 Structural design of cold plate
6.1 Fins
6.1.1 The shape of fins is usually straight, serrated and porous (see Figure 2). Other shapes of fins can also be selected upon request. 6.1.2 Basic principles for selecting fins
a. According to the working environment conditions of the cold plate, such as temperature, humidity, air pressure and pollution degree, select the shape, fin spacing, rib height and fin thickness.
Straight
Porous
Figure 2 Shape of fins
b. The operating pressure of the cold plate should generally be less than 2 000 kN/m. For large convective heat transfer coefficient, choose thick and low fins; for small convective heat transfer coefficient, choose high and thin fins. For large temperature difference between the cold plate surface and the environment, choose straight fins; for small temperature difference, choose serrated fins. d.
The fins supplied by the injection molding factory that has been identified as qualified by the relevant departments should be selected, and the technical parameters required for the design should be provided. 6.2 The end capping shape of the lifting plate can be designed into a tail shape, a fine shape, a rectangle or a convex rectangle according to the structural requirements (see Figure 3). Swallow-tail shape
Swallow-tail shape
Convex rectangle
6.3 The cover plate, bottom plate and partition plate of the cold plate (for multi-layer cold plates) are generally designed to be straight, and their thickness is designed according to the strength requirements. Both the cover plate and the bottom plate can be the heat bearing surface of the electronic components.
GB/T15428—1995
6.4 "The end caps, cover plates, fins and bottom plates on the side shall be welded into cold plate devices according to the requirements of the structural design. The surfaces shall be free of soldering liquid, burrs and degreasing to keep the surface flat and smooth. The channels of the cold plate shall remain smooth. 6.5 The channels of the cold plate shall be tested for sealing as required. Under the specified working pressure, there shall be no fluid leakage. 6.6 Effective measures shall be taken (such as applying thermal conductivity and grease).To minimize the contact thermal resistance between the electronic components or parts and the cold plate surface.
7 Performance inspection of cold plate
7.1 Structural performance
Disk. Check the appearance and shape of the cold plate by visual inspection. Each surface should be flat and the flow channel should be smooth. h Each structural dimension should meet the requirements specified in the design drawings. 7.2 Thermal performance
According to the distribution (uniform or concentrated) form of the heat load, under the condition of applying the heat load, measure the temperature distribution on the surface of the cold plate a.
Measure the pressure of the coolant at the inlet and outlet of the cold plate channel under the condition of applying the heat load. b.
c.Measure the flow rate (or flow velocity) of the coolant in the cold plate channel under the condition of applying the heat load. The measurement of the surface temperature of the cold plate, the flow rate and pressure drop of the coolant in the channel shall be carried out in accordance with the provisions of the corresponding chapters of GB12993. d.
The measured data shall be processed and summarized, and an evaluation report on the performance of the cold plate shall be written. e
GB/T15428—1995
Appendix A
Physical parameters of commonly used cold plate coolants
(Supplement)
A1 Physical properties of coolants (air) for air-cooled cold plates are shown in Table A1. Table A1
(kJ/kg·K)
Thermal conductivity
×1°W/mK
Physical properties of commonly used coolants for liquid-cooled cold plates (20℃) are shown in Table A2. Boiling point
Compounds
Physical properties of coolants for heat storage cold plates are shown in Table A3. Name
Latent heat of vaporization
Dynamic viscosity
Xlo°kg/m -g
Thermal conductivity
(kJ/kg-K)
Thermal conductivity
X102W/mk
Relative viscosity
X10°m*/s
Dynamic viscosity
kg/m·s
100.15×10
55×10
kJ/kgk
Latent heat of vaporization
Compatibility
LiNO, * 3HO
Note: "V\ indicates compatibility with most materials. Rib height!
Straight
Sawtooth
Porous
Latent heat of vaporization
GB/T 15428-1995
Continued Table A3
Liquid 1430
Solid 917
Liquid 1000
Appendix B
Thermal conductivity
X10W/mk
Structural parameters of some domestic cold plate fins
(Supplement)
Unit width channel
Cross-sectional area S:
3.74×10-
5.40×10-5
5.27×10a
8.37×10-*www.bzxz.net
7.63×10-#
9. 09×105
3.74×103
5.40×103
4.87×10°*
5. 67×10~5
8. 37×10-
3. 74×10: s
5. 40×10-*
5.27×105
8.37×10-
7.63×103
9. 09×10 4
Rib
Weight per unit area S
kJ/kgK
Equivalent diameter
Auxiliary area and heat transfer
area ratio A7A
Compatibility
Weight per unit area of ​​rib
C1 See the relationship curve of j-Re, s-Rc Cl,.
GB/T 15428—1995
Appendix C
Cold plate design coefficient curves
(supplement)
1.—Straight, 2--Corrugated, 3-Tooth
C2 Rectangular auxiliary plate channel K, K, coefficients see Figure C2. Triangular auxiliary plate channel K. K. coefficients see Figure C3. 10000
20000Re
GB/T15428—1995
K4LLL4A
Re= 2000
Re =a 000
-- Rc = 5 000
- Re= LD GDU
/Re= 0o
Re= cc
Re - 10 000
>Re=5000
Re=300
Re=2 DO0
Additional notes:
GB/T 15428—1995
Be = 2 000
Re=8000
_Re = 6 000.
Re=10 000
FRe=o0
Re= 10 000
Re=5 00D
Re-2 (0
This standard was proposed by the National Technical Committee for Standardization of Electrical and Electronic Equipment Structures. This standard was drafted by the Department of Mechanical Engineering of Southeast University. The drafters of this standard are Xie Deren and Xue Chengqi.27×105
8.37×10-
7.63×103
9. 09×10 4
Channel cross-sectional area per unit area S
kJ/kgK
Equivalent diameter
Auxiliary area and heat transfer
area ratio A7A
Compatibility
Rib weight per unit area
C1 See the relationship curve of j-Re and s-Rc in Cl,.
GB/T 15428—1995
Appendix C
Cold plate design coefficient curves
(Supplement)
1.—Straight, 2--Corrugated, 3--Tooth
C2 Rectangular auxiliary plate channel K, K, coefficients see Figure C2. Triangular auxiliary plate channel K. K. The coefficients are shown in Figure C3. 10000
20000Re
GB/T15428—1995
K4LLL4A
Re= 2000
Re =a 000
-- Rc = 5 000
- Re= LD GDU
/Re= 0o
Re= cc
Re - 10 000
>Re=5000
Re=300
Re=2 DO0
Additional notes:
GB/T 15428—1995
Be = 2 000
Re=8000
_Re = 6 000.
Re=10 000
FRe=o0
Re= 10 000
Re=5 00D
Re-2 (0
This standard was proposed by the National Technical Committee for Comprehensive Standardization of Electrical and Electronic Equipment Structures. This standard was drafted by the Department of Mechanical Engineering of Southeast University. The drafters of this standard are Xie Deren and Xue Chengqi.27×105
8.37×10-
7.63×103
9. 09×10 4
Channel cross-sectional area per unit area S
kJ/kgK
Equivalent diameter
Auxiliary area and heat transfer
area ratio A7A
Compatibility
Rib weight per unit area
C1 See the relationship curve of j-Re and s-Rc in Cl,.
GB/T 15428—1995
Appendix C
Cold plate design coefficient curves
(Supplement)
1.—Straight, 2--Corrugated, 3--Tooth
C2 Rectangular auxiliary plate channel K, K, coefficients see Figure C2. Triangular auxiliary plate channel K. K. The coefficients are shown in Figure C3. 10000
20000Re
GB/T15428—1995
K4LLL4A
Re= 2000
Re =a 000
-- Rc = 5 000
- Re= LD GDU
/Re= 0o
Re= cc
Re - 10 000
>Re=5000
Re=300
Re=2 DO0
Additional notes:
GB/T 15428—1995
Be = 2 000
Re=8000
_Re = 6 000.
Re=10 000
FRe=o0
Re= 10 000
Re=5 00D
Re-2 (0
This standard was proposed by the National Technical Committee for Comprehensive Standardization of Electrical and Electronic Equipment Structures. This standard was drafted by the Department of Mechanical Engineering of Southeast University. The drafters of this standard are Xie Deren and Xue Chengqi.
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