Bespoke cooling solutions pay off
Replacing a refrigeration system is a complex undertaking that requires careful planning and expertise.
Refrigeration for a renowned research facility
Research facilities, like many other areas of application, depend on reliable process cooling and air conditioning for their buildings, systems and projects – whether on a private campus in the pharmaceutical and chemical industry or at a university. At the same time, most internal sustainability guidelines require infrastructure facilities to be operated in an energy-efficient manner, using renewable energies. Many research complexes therefore operate their own cooling network, which flexibly supplies the various facilities and projects with cooling. However, a sustainable and safe concept for refrigeration provides more than ‘just’ cooling. In fact, a modern chiller can also process the (waste) heat so that it can be used in the heating network for the various buildings on the campus.
High demands on efficient and flexible power control
One example of such a sustainable and safe refrigeration solution was also tested by a globally networked research institution in German-speaking Switzerland after its existing cooling generators had reached the end of their service life. To replace the process chiller for the cooling network, the infrastructure managers initially looked for a supplier who could provide a cost-effective, outdoor standard cooling generator. In addition to the standard solution, CTA also proposed a contractor variant with a customised, tailor-made refrigeration solution. This energy-optimised chiller enables annual energy savings of up to 25 per cent and optimally meets the needs of the research institution identified by the CTA experts.
The 26-tonne chiller was designed so that it could be transported in three parts and assembled on site.
Sophisticated control of the finer operating points
The highlight of the contractor variant is that the chiller’s control unit supports several operating points with their respective set point specifications for air conditioning and process cooling. Winter and summer operation as well as demand-dependent waste heat utilisation are taken into account. From low load in winter to full load in summer, a total of 17 operating points can be individually controlled. With this capacity control, cooling requirements and cooling generation can be precisely adjusted.
The installed chiller
The CTA's robust chiller supplies the cooling network with cold water at 16 °C or 24 °C, depending on the operating mode (air conditioning or process cooling). The cooling generator has three large screw compressors, each with a cooling capacity of 500 kW. Each compressor can be infinitely adjusted between 50 and 100 per cent using a frequency inverter, which in turn enables cooling requirements and cooling generation to be managed perfectly. For further efficiency gains, the CTA engineering team equipped each of the three refrigeration circuits with a subcooler after the condenser. This cools the refrigerant further with the return flow from the hot water network, thereby increasing energy efficiency. During operation with heat utilisation, a large temperature spread (44/64 °C) is intentionally used to enable high subcooling.
The reversible chiller installed
Outstanding COP value of 4.67 in waste heat utilisation mode
17 operating points
Three speed-regulated screw compressors
Prefabricated and separately delivered parts (refrigeration, hydraulic and dry cooler parts)
Custom-made CTAexklusiv
Heat pump operation with groundwater
Over the course of the year, the chiller can feed 90 per cent of the heat generated into the local heating network. It can supply hot water at up to 64 °C. Only at the height of summer does some of the heat have to be dissipated via the recooler. In winter, it can be the case that only a little process cooling is required while there is simultaneously heavy demand for heating. In such cases, the chiller is switched to ‘heat pump mode’. It will then extract heat from the groundwater or from the air and feed the energy into the local heating network.
Pays for itself rapidly
Although CTA's contractor solution has around 40 per cent higher investment costs than the standard solution, this pays off in the long term. This is because over the entire service life of 15 to 20 years, the contractor solution is often significantly more economical thanks to lower energy costs, in addition to the other benefits. Ideally, the additional investment costs will be recouped within the first half of the system's service life. Another argument in favour of the customised CTA machine was the size of the refrigeration system. The entire chiller is an impressive 13 metres long and 5.5 metres high and weighs 26 tonnes. In order to transport the system from Münsingen to the customer without too much effort, it was designed so that it could be transported in three parts – cooling generator, heat recovery and recooler – and assembled easily on site.
Lower energy costs
Over the entire service life of 15 to 20 years, the contractor solution – apart from the additional benefits – is often significantly more economical thanks to lower energy costs.
In safe hands
CTA's service technicians ensure that the systems will not need to be replaced for quite some time. They maintain the systems at regular intervals and thus promote trouble-free operation over the long term. CTA offers its customers a diverse service package: Customers can choose the service that best suits their needs, from standard to flat-rate maintenance to the CTAprotect all-round no-hassle package with a warranty extension of up to 15 years.
Does your unit need to be replaced soon?
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