IEC 62610 4 Edition 1 0 2013 08 INTERNATIONAL STANDARD NORME INTERNATIONALE Mechanical structures for electronic equipment – Thermal management for cabinets in accordance with IEC 60297 and IEC 60917[.]
Terms and definitions
For the purposes of this document, the following terms and definitions apply
Q removed heat load given by the electronic equipment mounted inside the electronic cabinet
3.1.2 absolute humidity mass content of water (gram of water) per defined mass of dry air (kilogram of air) [g/kg] g of water per kg dry air
A dummy device designed to simulate the heat load of typical electronic devices in information technology features a horizontal airflow system, with air intake located at the front and air outlet positioned at the rear of the equipment.
Note 1 to entry: The air flow orientation is defined in IEC 60297 (19 in) and IEC 60917 (25 mm) standard series cabinet design
3.1.4 sensible cooling cooling capacity to provide air temperature change only The absolute humidity of air in sensible cooling process is unchanged
The simplified test method outlined in section 3.1.5 does not take into account the effects of heat transfer through the walls of the electronic cabinet, nor does it consider the heat transfer caused by air leakage in and out of the electronic equipment housing.
3.1.6 extended test this test method does not consider the heat transfer by leaking air in and out of the housing of the electronic equipment
Symbols and units
P el electrical power consumption [kW]
Q air heat flow of the cooling air [kW] v air air velocity (test result) [m/s]
A air air cross-section [m 2 ] ρ air air density (related to 101,325 kPa air pressure) [kg/m 3 ] air c p , specific heat capacity of air [kJ/kgK] δ T temperature difference [K]
T CW δ temperature difference of the chilled water between supply and return [K]
T air δ temperature difference of the cooling air between equipment air inlet and air outlet
[K] f factor based on specific heat capacity of water [l/s, l/min, m 3 /h]
Q CW heat flow in chilled water [kW]
V CW chilled-water flow [l/s, l/min, m 3 /h]
Q S cooling capacity of the IT equipment [kW]
4 Performance test for the heat exchanger
General
For testing the heat exchanger performance, the following parameters shall be applied:
During the test, the heat load of the dummy equipment must remain constant The heat dissipation from the heat load dummies will be measured and documented in the test report, as outlined in Table B.1 This measurement of heat dissipation will be based on the electrical power consumption.
During all measurements all control function and algorithm of the tested unit shall be disabled
The air temperature near electronic equipment, specifically between the front panel and door, must adhere to the range specified in Annex A, allowing a maximum tolerance of ± 1 K across various temperature sensors Additionally, the temperature difference between the air inlet and outlet of the dummy heat loads should not exceed the limits outlined in Annex A.
The test report must include the recorded temperature difference, which should be measured with an accuracy of 0.2 K for the air temperature.
The maximum allowable temperature difference between the chilled water supply and the air inlet temperature of the equipment dummies must not exceed the limits specified in Annex A This temperature difference should be measured as an average after all temperatures have stabilized during testing The results of the measured temperature difference must be documented as indicated in Table B.1 Additionally, the chilled water supply temperature may vary by up to 1 K during the test, and the air temperature difference in the test report must be determined with precise accuracy.
0,1 K The temperature difference of the water temperature in the test report shall be recorded within an accuracy of 0,1 K See Table B.1
The pressure resistance of the air water heat exchanger in the chilled water system must not exceed the limits specified in Annex A during testing This resistance encompasses all hydraulic components necessary for the heat exchanger's operation, including modulating valves, balancing valves, and connectors Additionally, the pressure difference and its relationship to the chilled water flow rate should be documented in the table and chart outlined in Annex B.
The increase in water temperature between the inlet and outlet of the heat exchanger is a key test result that must be documented in the test report, as outlined in Annex B Additionally, the chilled water flow rate should also be recorded in the test report, following the specified table and chart.
The flow rate must be chosen to ensure that the maximum pressure difference specified in Annex A is not surpassed It should be measured with a tolerance of ± 2%, and the recorded pressure difference must be included in the test report, following the guidelines outlined in Annex B.
The air temperature of the test chamber shall be in the same range as the temperature inside the cabinet, in front of the electronic equipment
The test room's changing humidity conditions are not acknowledged for the determination of the test The cooling capacity is regarded as 100% sensible cooling, indicating that, based on the conditions outlined in section 4.2.1 and a chilled water feed temperature tolerance of ±1 K, the chilled water feed temperature must exceed 12 °C.
Figure 1 – Principle of the heat exchanger performance test
Test setup
Assessment of the heat exchanger performance
Determination of the cooling capacity by means of simplified tests
A simplified test method for assessing the cooling capacity of closed cabinets containing electronic equipment assumes that the heat exchanger's cooling capacity exceeds the heat absorption of the cabinet panels This method is suitable for cooling capacities greater than 12 kW, provided that the heat absorption of the cabinet panels is below 600 W (less than 5%) For cooling capacities under 12 kW, alternative testing procedures are outlined.
The cooling capacity of the heat exchanger is determined by the air intake temperature of the electronic equipment, as detailed in Annex A, with a mean value of ± 0.2 K This useful cooling capacity can now be accurately measured using heat load dummies.
The fans utilized in the tested sample cabinet must operate at the manufacturer's specified normal RPM It is important to note that fan redundancy concepts will not influence the test results and are not addressed by this standard.
The test setup conditions as described in 4.2 shall be met
The fans in the sample must operate at nominal speed, ensuring that any redundancy in the fan design is maintained during cooling capacity tests When selecting fan speed for testing, it is crucial to avoid impairing redundancy Additionally, fan performance should be adjusted to account for redundancy, allowing for the possibility of switching off fans for separate tests without compromising cooling capacity.
Furthermore, the test conditions as described in 4.2 shall be met
P el electrical power consumption [kW]
Figure 2 – Test setup of simplified tests Determination of the cooling capacity by way of an extended test
The extended test method measures the heat flow discharged from a sample using chilled water, enabling the calculation of the difference between the applied heat load and the heat flow released This process reveals the heat flow discharged through the housing shell, primarily due to convection at the cabinet's covering parts Additionally, air leakage from the sample can contribute to material-borne heat transfer This method provides informative test results for heat flows below 12 kW.
The extended test method records the actual temperature increase of the chilled water return from the test sample This allows for the calculation of the difference between the heat dissipated and absorbed by the chilled water system and the heat absorbed by the cabinet covers.
It is to be noted that unwanted air leakage of the cabinet may effect the calculation negatively
To determine the temperature rise of the chilled water return, it is essential to measure the chilled water flow rate, which should be accurate within ± 2%.
(heated) chilled water return shall be calculated as follows:
Supply air to cool equipment
Supply air to cool equipment
Air inlet temperature equipment dummy [°C ± 2 °C]
Dew point temperature 10,5 °C ± 0,5 °C air-water heat exchanger
Electrical power consumption air-water heat exchanger
Cabinet with bottom mount heat exchanger Side view
Cabinet with side mount heat exchanger Top view
Air temperature test room = Air inlet temperature equipment dummy [°C ± 2 °C]
Absolute humidity 8 g ± 0,5 g/kg Dew point temperature 10,5 °C ± 0,5 °C
Chilled water return supply Fan
To accurately determine the heat flow discharged from the sample using chilled water, it is essential to measure the water flow with a precision of ± 2% The calculation of the heat flow is based on this precise measurement.
Based on the given measurement unit of the flow rate the f factor implements the specific heat capacity to formula 3 as follows f = 4,19 at
V CW l determining the chilled water flow rate in
V CW l determining the chilled water flow rate in
3 determining the chilled water flow rate in
The test conditions as described in 4.1 and the method as described in 4.2.1 apply to determining the cooling capacity
The heat flow leaving the sample by way of chilled water applies to determining the cooling capacity
Figure 3 – Test setup of extended tests Complete identification of the cooling capacity
The heat flow exiting the sample can be measured through the cooling water, while the heat flow entering the heat exchanger and the cooling air can also be assessed This incoming heat flow should align with the cooling capacity represented by the heat flow leaving the sample via chilled water.
A discrepancy observed between two air flows from the same sample may indicate air leakage If the difference in heat flows exceeds 5%, it is essential to inspect the sample's setup, focusing on the internal air leakage volume The goal is to minimize air leakage to a maximum of 5%.
To determine the heat flow of cooling air, it is essential to measure the air flow at the inlet or outlet of the heat exchanger This involves using appropriate measurement instruments to assess the air flow rate at multiple points within a defined flow cross-section, ultimately calculating the mean value It is crucial that the measuring instrument does not disrupt the air flow The outcome reflects the volume of cooling air passing through the heat exchanger over time The measurement process, which focuses on air velocity in a specific cross-section, incorporates the flow rate as a function of cross-section and air velocity, as outlined in formula 5 This testing method also provides valuable results for heat flows below 12 kW.
Supply air to cool equipment
Supply air to cool equipment air-water heat exchanger
Chilled water return supply air-water heat exchanger
Cabinet with bottom mount heat exchanger
Cabinet with side mount heat exchanger top view
Air inlet temperature equipment dummy [°C ± 2 °C]
Air temperature test room = Air inlet temperature equipment dummy [°C ± 2 °C]
Absolute humidity 8 g ± 0,5 g/kg Dew point temperature 10,5 °C ± 0,5 °C
Chilled water return supply Fan
IEC 2112/13 air air p air air air air v A c T
Figure 4 – Test setup, test for complete identification of the cooling capacity
Supply air to cool equipment
Supply air to cool equipment air-water heat exchanger
Temperature sensors air-water heat exchanger
Cabinet with bottom mount heat exchanger
Cabinet with side mount heat exchanger top view
Air inlet temperature equipment dummy [°C ± 2 °C]
Air temperature test room = Air inlet temperature equipment dummy [°C ± 2 °C]
Absolute humidity 8 g ± 0,5 g/kg Dew point temperature 10,5 °C ± 0,5 °C
Electrical power consumption
The electrical power consumption of the cooling system will be measured during testing, and a diagram illustrating the relationship between electrical power consumption and cooling capacity will be presented as a test result (refer to Figure 5).
Figure 5 – Diagram of electrical power consumption versus cooling capacity
Water circuit pressure resistance
The test shall provide a diagram of the pressure resistance in the chilled water circuit (see
Figure 6 – Diagram of water pressure resistance versus water flow rate
Pressure difference chilled water circuit [kPa]
A.1 Closed air loop air to water heat exchanger for high density cooling systems for IT equipment and server cooling
Air intake temperature of the dummy equipment: 18 °C to 27 °C
Temperature difference between air intake and air outlet of the equipment dummy: 20 K or less
Temperature difference between air intake temperature into the equipment and chilled water supply temperature: 10 K or less
Chilled water supply temperature shall stay between 12 °C and 25 °C
During the test the pressure resistance of the air water heat exchanger between chilled water supply and chilled water return of the chilled water system shall not exceed 100 kPa
This pressure resistance shall include all hydraulic components for the heat exchanger operation e.g modulating valves, balancing valves, connectors
The pressure difference between front sides and the rear side of the dummy equipment shall between 0 Pa and 10 Pa ± 1 Pa
A.2 Closed air loop cooling systems for industrial/telecom air to water heat exchangers
Air intake temperature of the dummy equipment: 35 °C to 55 °C
Temperature difference between air intake and air outlet of the dummy equipment: 25 K or less
Temperature difference between air intake temperature and chilled water supply temperature:
Chilled water supply temperature shall stay between 12 °C and 25 °C
During the test the pressure resistance of the air water heat exchanger between chilled water supply and chilled water return of the chilled water system shall not exceed 300 kPa
This pressure resistance shall include all hydraulic components for the heat exchanger operation e.g modulating valves, balancing valves, connectors
The pressure difference between front sides and the rear side of the dummy equipment shall between 0 Pa and 20 Pa ± 1 Pa
Table B.1 – Test result recording template
Electrical power consumption of the equipment dummies: [kW]
Total electrical power consumption of the unit: [W]
Temperature increase between chilled water supply and return [K]
Chilled water system pressure difference
Air temperature at equipment dummy air inlet [°C]
Air temperature at equipment dummy air outlet [°C]
Temperature difference between air inlet and air outlet at the equipment dummy [K]
Pressure difference between front sides and the rear side of the dummy [Pa]
Figure B.1 – System cooling capacity and water flow rate B.2 Test result recording template
Table B.2 – Test for closed air loop air to water heat exchanger for high density cooling systems for IT equipment and server cooling
Electrical power consumption of the equipment dummies: 35 kW
Total electrical power consumption of the unit: 1 500 W
Temperature increase between chilled water supply and return 6,0 K
Chilled water system pressure difference
Air temperature at equipment dummy air inlet 21,0 °C
Air temperature at equipment dummy air outlet 40,3°C
Temperature difference between air inlet and air outlet at the equipment dummy 19,3 K
Pressure difference between front sides and the rear side of the dummy 5 Pa
All conditions according Clause A.1 are in the allowed limits
Test performed according to 4.3.1 (simplified tests)
Pressure difference chilled water circuit [kPa]
Electrical power consumption of equipment equals system cooling capacity [kW]
3 Termes et définitions, symboles et unités 24
4 Essai de performances de l'échangeur de chaleur 26
4.2.2 Simulation de la charge thermique de l'équipement dans l'échantillon d'essai 27 4.2.3 Débit et températures d'eau réfrigérée 28
4.2.4 Mesure de la température de l'air 28
4.2.5 Différence de température entre l'arrivée de l'eau réfrigérée et l'entrée d'air de l'équipement 29 Evaluation des performances de l'échangeur de chaleur 29
4.3.1 Détermination de la capacité de refroidissement au moyen d'essais simplifiés 29 4.3.2 Détermination de la capacité de refroidissement au moyen d'un essai étendu 30 4.3.3 Identification complète de la capacité de refroidissement 32
Résistance à la pression dans un circuit d'eau 34
Figure 1 – Principe de l'essai de performances de l'échangeur de chaleur 27
Figure 2 – Montage d'essai des essais simplifiés 30
Figure 3 – Montage d'essai des essais étendus 32
Figure 4 – Montage d'essai, essai d'identification complète de la capacité de refroidissement 33
Figure 5 – Schéma de consommation électrique en fonction de la capacité de refroidissement 34
Figure 6 – Schéma de résistance à la pression de l'eau en fonction du débit d'eau 34
Figure B.1 – Capacité de refroidissement du système et débit d'eau 37
Tableau B.1 – Modèle d'enregistrement de résultats d'essais 36
Tableau B.2 – Essai pour échangeur de chaleur air-eau à boucle d'air fermée pour des systèmes de refroidissement à haute densité pour le refroidissement de serveurs et d'équipements de technologies de l'information 37
STRUCTURES MÉCANIQUES POUR ÉQUIPEMENTS ÉLECTRONIQUES – GESTION THERMIQUE POUR LES ARMOIRES CONFORMES AUX SÉRIES CEI 60297 ET CEI 60917 –
Partie 4: Essais de performances de refroidissement pour les échangeurs de chaleur alimentés par de l'eau dans des baies électroniques
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La Norme internationale CEI 62610-4 a été établie par le sous-comité 48D: Structures mécaniques pour équipement électronique, du comité d'études 48 de la CEI: Composants électromécaniques et structures mécaniques pour équipements électroniques
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Cette publication a été rédigée selon les Directives ISO/CEI, Partie 2
Une liste de toutes les parties de la série CEI 62610, présentées sous le titre général
Structures mécaniques pour équipements électroniques – Gestion thermique pour les armoires conformes aux séries CEI 60297 et CEI 60917, peut être consultée sur la site web de la CEI
The committee has determined that the content of this publication will remain unchanged until the stability date specified on the IEC website At that time, the publication will be updated accordingly.
• remplacée par une édition révisée, ou
The electronic racks of the IEC 60297 and IEC 60917 series are designed to house electronic devices across various applications A significant area of application includes communication network installations that utilize electronic devices in information technology environments A typical setup involves arranging rows of racks in an occupied area and interconnecting them with cables routed through overhead trays or under the floor.
Until now, cooling has been managed by an air conditioning system in the data center to maintain the necessary airflow and temperature for the proper functioning of electronic devices However, as temperatures rise in data processing centers, this method of cooling is becoming less effective The thermal issues associated with high-performance electronic devices are increasingly complex to address Environmental considerations are becoming critical, necessitating a reduction in resource waste and CO₂ emissions.
Il est donc nécessaire de trouver des alternatives à la climatisation des salles L'amélioration de l'efficacité du refroidissement repose sur des concepts, dont deux sont donnés à titre d'exemple ici:
Cas 1 Groupe de baies avec contrôle de température dédié
This method involves placing a smaller number of berries, typically between four and twelve, in cold and warm aisles Its advantage over air conditioning in rooms is the reduced air volume, allowing for targeted heat management with optimized energy consumption for cooling devices and higher temperatures in the warm areas of the room.
In this case, efficiency can be enhanced by recovering heat to warm rooms during cold periods This method is gaining popularity due to its contribution to improved energy efficiency.
Cas 2 Baies seules avec échangeurs de chaleur eau-air
This method is utilized for racks housing electronic equipment that generates significant heat, typically servers and mainframe computers Its advantage over traditional air conditioning or hot and cold aisles is the provision of a more consistent air intake temperature for sensitive electronic devices The closed-loop airflow within a rack allows for precise temperature control While energy consumption may be comparable to that of a cold aisle, the enhanced temperature regulation extends the lifespan of expensive equipment.
This standard has been established to address performance testing for cooling systems in heat exchangers powered by water in single electronic bay configurations The parameters related to the test sample are illustrated in diagrams that provide a standardized calculation method for bay dimensions and specific cooling requirements of heat exchangers Typically, the cooling capacity required for such bays exceeds 12 kW The testing methods outlined in this standard focus on cooling capacities above this threshold.
12 kW Cependant, puisque les équipements de technologies de l'information font varier la charge thermique d'une baie, l'essai porte également sur des valeurs inférieures à 12 kW pour les charges thermiques partielles
STRUCTURES MÉCANIQUES POUR ÉQUIPEMENTS ÉLECTRONIQUES – GESTION THERMIQUE POUR LES ARMOIRES CONFORMES AUX SÉRIES CEI 60297 ET CEI 60917 –
Partie 4: Essais de performances de refroidissement pour les échangeurs de chaleur alimentés par de l'eau dans des baies électroniques
This section of IEC 62610 outlines the testing setups and parameters for water-cooled heat exchangers in single electronic bay configurations The tests focus on bays designed for the installation of high-power electronic equipment The relevant bays comply with the specified series.