Technical Design-in Guide Engine QLE G2 PRE KIT | 01-2019 | 1.0 | en
Thermal Aspects
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7.1. Passive cooling
Heat transfer from a heat source to the surrounding cooling medium (e.g. air) depends primarily on the difference in temperature, the
effective surface area and the flow rate of the cooling medium. The function of a heat sink is to increase the surface area over which
the heat can be dissipated. This lowers the thermal resistance.
A passive heat sink works mainly by convection. The surrounding air is heated, which makes it rise, and is replaced by cooler air.
Heat pipes can be used as an alternative to cooing with fans. If space is particularly tight, the heat is first conveyed away. The actual
heat sink is located at the other end of the heat pipe.
Benefits of passive cooling
7.2. Module cooling
7.2.1. Effect of cooling on the life of the modules
The modules of the Engine STARK QLE system are self-cooling and a heat sink is not required. The life of the module depends to a
large extent on the operating temperature. The more that the operating temperature can be reduced, the longer the expected life of
the module. If the permitted operating temperature is exceeded, however, the life of the module will be significantly reduced.
Fall in luminous flux over the course of the service life:
The diagram shows the change in luminous flux in percent over an operating time of 1,000 h at different t operating temperatures.
c
Luminous flux
Operating time at t = 65 °C
c
80 %
30,000 h
70 %
50,000 h
Energy savings
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Silent
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No mechanical wear
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No maintenance
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