What are the differences between the air-cooled and the liquid cooled electrolyser?

The air-cooled and liquid-cooled electrolyser are nearly identical devices. The only difference is in the heat exchanger subassembly, which has the primary function to maintain a stable electrolyte temperature for the electrolyser operation. Air-cooled The air-cooled electrolysers use a fan

February 19, 2022

The air-cooled and liquid-cooled electrolyser are nearly identical devices. The only difference is in the heat exchanger subassembly, which has the primary function to maintain a stable electrolyte temperature for the electrolyser operation.

Air-cooled

The air-cooled electrolysers use a fan to blow ambient air past the electrolyte in order to keep the electrolyte at the nominal operating temperature, currently 55°C. For the air-cooled unit, the customer must supply fresh air at the correct temperature to the front of the device, and the device will eject warmer air out of the back. The customer must ensure sufficient air flow can freely flow.

Pros: uses ambient air, therefore easy and fast to set up

Cons: in small rooms or containers, puts higher requirements on HVAC and installation space

Liquid-cooled

The liquid-cooled electrolysers have a liquid-liquid heat exchanger and use a valve to start/stop the flow of a cooling liquid that must be supplied by the customer. The liquid-cooled version of the electrolyser only has minimal air flow requirements for safety purposes and to cool the electronics, therefore the space required for installation due to air flow requirements is reduced. It has an additional cooling liquid inlet and outlet on the front panel. The customer must supply pressurized cooling liquid at the inlet, and the device will release the cooling liquid at a slightly higher temperature from the outlet. The temperature increase depends on the supplied pressure and flow rate, but in any case, the quality of heat obtainable is limited as the operating temperature of the electrolyte is currently just 55°C.

Pros: more compact setup as air flow requirements is reduced

Pros: reduced requirements on the HVAC system for indoor installations

Cons: requires additional efforts from the integrator to provide the cooling liquid

Using waste heat

In both the air-cooled and liquid-cooled cases, the total waste heat energy from the electrolysis process is the same. This waste heat, while of relatively “low quality”, could potentially be used by integrators in some specific applications to increase overall efficiency of their energy systems. In most cases however, it is just released to the environment.