Patented refrigerant charge balancing technology - Efficient heating and cooling of electric buses

Konvekta AG presents another innovation in heating technology for electric buses: „refrigerant charge balancing“ as the latest module of the CO2 heat pump. This advanced technology improves once more efficiency and range - it is another step towards more energy-efficient thermal management for electric buses.

Electromobility is becoming increasingly important, especially in local public transport (LPT). Electric buses can avoid local exhaust emissions during operation, but still place high demands on range and charging times.

Manufacturers of electric buses are working on improving the energy efficiency of the vehicle as well as that of the secondary consumers.  The heating and air conditioning system offers great potential for saving energy. By using ambient heat, the electrical energy required for heating can be reduced.

By using heat pump concepts and an optimized control system, the overall efficiency of electric buses can be significantly improved. CO2 heat pumps do not draw most of their energy from the battery but from the ambient air. 
All year round CO2 heat pump systems provide both efficient cooling in summer and reliable heating in winter. This is a major challenge because of the optimal refrigerant charge, which can vary according to heat demand, outdoor temperature, or operating mode, and thus has a direct impact on the system performance. With the new „refrigerant charge balancing“ module, the refrigerant charge level is precisely controlled, ensuring that the optimal quantity of refrigerant is always available to the system.

This is made possible by the use of patented valve technology, the exclusive Konvekta heat exchanger design and the specially developed control technology that specifically controls the refrigerant.
 

CO2 thermal management consists of two circuits - one for heating and one for cooling. For example, the energy-intensive heating operation increases the demand for refrigerant. The inactive circuit - the cooling circuit - now acts as a resource source and provides the active circuit with the missing quantity of refrigerant. The performance of the system is thus significantly optimized, so that efficiency is increased and energy consumption is reduced. The lower energy demand can reduce the electricity consumption of the thermal management system and, in turn, operating costs.

Another advantage of the „refrigerant charge balancing“ is that the system always operates in an optimal range due to the targeted control of the filling level so that the load on the components in the overall system is reduced. This extends the life span of the system and reduces maintenance requirements.

CO2 thermal management also uses the natural refrigerant CO2. CO2 is a natural component of the earth's atmosphere and is obtained as a waste product from industrial processes. CO2 is currently not subject to restrictions applying to fluorinated greenhouse gases. Availability and price may vary depending on market conditions. The natural refrigerant has no ozone depletion potential and therefore it does not damage the ozone layer.

The Konvekta - refrigerant charge balancing technology is the consequent further development of a system which sets new standards in the field of air conditioning and heating of electric buses again and again, with the aim of reducing energy demand and maintenance requirements in electric-bus thermal management.