Innovation in an Existing Backpressure Turbine for Ensure Better Sustainability and Flexible Operation

Cogeneration power plants have already been operated in the Czech Republic for several decades. These cogeneration power plants have been mostly operated with original technologies. However, these original technologies have to be continuously innovated during the entire operation time. This paper is focused on one of the possible innovations, which could lead to better sustainability and improved flexibility of the cogeneration power plants. Backpressure turbines are still used in many cogeneration power plants. However, backpressure turbines are currently losing suitability for cogeneration power plants, because they always need sufficient heat demand for optimal operation. Backpressure turbines rapidly lose efficiency when facing a lack of heat demand, i.e., mostly in summer season. Currently, condensing turbines are a preferable option for cogeneration power plants, which generally achieve less effective operation, as condensing turbines are able to operate with optional heat demand. Therefore, backpressure turbines are often replaced by condensing turbines with regulated outputs. In spite of the current trend, this article will present an innovative topology, which retains the original backpressure turbine with the addition of the organic Rankine cycle for residual energy utilization.