Qnergy PowerGen 5650 Series, Installation & Operation Manual, Page: 27 / 194

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NTRODUCTION
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Figure 3-5 Piping and Instrumentation Diagram (P&ID)
3.2.3 COOLANT LOOP
Similar to an automotive cooling system, the PowerGen utilizes a high efficiency aluminum
radiator to dissipate unused, excess heat. A high efficiency PWM controlled circulating pump
circulates coolant throughout the PowerGen system at a controlled rate in order to maintain
optimal coolant temperatures under varying ambient and operating conditions. The coolant is
routed through the QEC, the motor-generator, as well as a number of other components
requiring active cooling. To monitor and control the fluid flow rate there is a flow sensor to
identify that the flow is within the required operating range.
A temperature sensor is used to add additional indication for loss of cooling. Two coolant
drains and an air relief valve are integrated into coolant loop sub-system to allow for draining
and filling coolant. The radiator fill port has a safety valve, releasing any access pressure build
up beyond 1.15bar and pulling coolant from the tank when a vacuum forms as a result of
thermal expansions.