Wien Energie and KLINGER Gebetsroither join forces for energy transition
In November 2017 the Austrian energy service provider Wien Energie held a groundbreaking ceremony for a very special facility. A little over half a year later, the project – the erection of Vienna's first large-scale heat pump – is rapidly nearing its completion. We sat down with Wien Energie Project Head Christoph Segalla to find out what its installation on the premises of the company's cogeneration plant in Vienna-Simmering means for the energy transition and what role KLINGER Gebetsroither played in its construction.
KN: Mr. Segalla, thank you for making time for this interview. Could you please start by telling us a bit about the origins of the project? CS: Gladly. Historically speaking, district heating mainly relies on gas to service its customers. Finding ways to counter an over-reliance on this fossil fuel and to bring more renewables to the energy mix is among the top priorities of Wien Energie to support the energy transition and to also reduce CO2 emissions. And this is why we came up with the idea of the large-scale heat pump.
KN: Can you tell us about the heat pump's working principle? CS: It is currently being installed at our cogeneration plant in Vienna-Simmering. In essence, it uses the cooling water of the power plant, into which the unusable heat from the cogeneration process is diverted, as its heat source. Our large-scale heat pump consists of two identical units, each with its own closed refrigeration circuit. The refrigerant medium absorbs the ambient heat via a heat exchanger, is compressed by means of an electrically powered compressor, and heated. The refrigerant is then returned to its fluid phase and the generated waste heat is fed into the district heating water. Starting with a temperature of 6 °C, we can also use the "Donaukanal" (a regulated side arm of the Danube river) as a heat source to generate heat of more than 90 °C.
KN: Out of interest, we are speaking about a large-scale heat pump after all, how large is it? CS (grins): Definitely larger than your average household appliance. As I have already explained, our solution consists of two identical heat pumps. They have a rectangular shape and are 20 meters long, 8 meters wide and their height is also 8 meters. Their weight might actually be an even more impressive figure – each of the pumps weighs 180 tons, so we are talking about a combined weight of 360 tons.
KN: Now that sounds like a challenge in itself. Speaking of which, can you tell our readers how far the project has so far progressed and what challenges one encounters in such a project? CS: Following our groundbreaking ceremony in November of last year, we have almost completed the entire construction phase. With regard to the pipe system, we are in the final assembly stage, and are also working on the remaining cabling and insulation tasks. As a consequence, we are confident that we will be able to complete the construction by mid August and will then begin the commissioning phase, which will start with cold commissioning.
KN: And the challenges you encountered? CS: First off, you have to understand that this is the first major heat pump project that we have ever undertaken, meaning this was also new territory for us and required careful planning. The aforementioned dimensions also posed a challenge as the heat pumps had to be installed into an existing building, a former turbine hall, with the aid of special heavy-duty cranes. Amongst others, we had to remove the old turbine core and strengthen the ground level of the building in order for it to sustain the weight of 360 tons.
KN: And what part did KLINGER play in the project? CS: KLINGER, in this case KLINGER Gebetsroither, has been our preferred gasket and valve partner, especially for our transmission pipelines, for many years. The products we use offer us numerous benefits, which go well beyond their top quality. For example, their design is a perfect match for our requirements, they feature a full bore that results in less frictional loss and they are characterized by excellent sealing properties. In this project, we rely on KLINGER KHI ball valves at the interfaces to the district heating system as well as within the heat pumps. Furthermore, we use KLINGER PSM gaskets for our applications as well.
KN: Are you satisfied with the products provided? CS: Absolutely, as stated, they are a perfect fit. I'd also like to mention the excellent cooperation we enjoyed in the course of the project. We had to set some very tight deadlines, and KLINGER delivered in their usual, professional manner, and were always ready and willing to provide their expertise in all matters pertaining to fluid control, wherever required. As a consequence, I am already very much looking forward to our large-scale heat pump launching into standard operation at the end of this year.
KN: By way of closing, could you tell our readers something about the performance rating your large-scale heat pump will have? CS: Yes. Following its completion, the heat pump will feature a performance of 10,000 KWh. It will provide around 25,000 standard households with district heating from a renewable source and will help us to save around 40,000 tons of CO2 emissions on an annual basis.