CHP modernization at Hamburg Airport completed

One of the oldest operating CHP plants in Germany on the grounds of Hamburg Airport was modernized step by step by S&L Energie-Projekte GmbH from 2021 to 2023 during ongoing operation. For reasons of changed demand, however, only 4 instead of the originally planned 6 Waukesha gas engines were ultimately renewed. The plant periphery was also extensively modernized.

Since 1992, Hamburg Airport has been operating a CHP plant with 6 chp units based on INNIO Waukesha rich burn (Lambda-1) gas engines with 645 kWe and 1,095 kWth each. The electrical and thermal output of the very robust 12-cylinder naturally aspirated engines with a displacement of 115 liters and 1,000 rpm is fed into the airport's respective grid.

After an operating period of 30 years with over 150,000 operating hours per engine, the CHP plant was comprehensively modernized from the beginning of 2021 while it was still in operation. For this purpose, the base engines were replaced by "long blocks" of the same type and the engine accessories were partly renewed and partly taken over from the existing engines. The engines were rebuilt at the Wulf Johannsen engine repair facility in Kiel. The 30-year-old steam generators were replaced by conventional heating water/exhaust gas heat exchangers. The control system was also adapted and the entire heating water piping system.

The decision in favor of the "extended general overhaul" and thus against a complete renewal of the CHP unit was made for economic reasons. The advantages of the Lambda-1 engines also played a role, as these have a high overall efficiency with low emissions, without additional space requirements and operating costs for an SCR exhaust gas cleaning system.

After 4 of the 6 modules had been replaced and the plant periphery modernized at the end of 2022, the customer decided against replacing the last 2 units due to the lower energy demand. Therefore, these were removed by S&L and the system periphery of these units was dismantled. Afterwards, the entire CHP hydraulics were optimized by the S&L Solutions team.

One of the oldest operating CHP plants in Germany was thus successfully made fit for the next (at least) 15 years. "While in the past old Lambda-1 engines were often replaced by modern lean-burn engines, today more and more owners are convinced to maintain the advantages of Lambda-1 technology," says Stefan Schöne, Service Manager and Project Manager at S&L. "In addition to the well-known advantages of the high overall efficiency and the simple as well as effective exhaust gas cleaning, today the particularly low methane emissions of Lambda-1 engines are increasingly coming to the fore. Compared with modern lean-burn engines, large quantities of methane emissions, which are particularly harmful to the climate, can be avoided here," added Raimund Dieckmann, S&L Managing Director. "Sometimes it is advantageous to fall back on old, proven technologies to solve the problems of today and tomorrow."