Chilling

Chilling is often used in industrial processes and commercial buildings. But did you know, that chilling is also needed when you make a phone call?

 

 

Where do we need chilling and why?

Cooling. First thing that might come to one’s mind about cooling is the fridge. As we know, some foods need to be stored cool to keep them fresh and last longer. In a typical fridge, electricity is being used to drive pumps and compressors which transfer the excess heat out of the fridge and to keep it in constant, desired temperature. Another similar application is air-conditioning. At home, air-conditioning devices come in many technologies and brands and provide comfort on a hot day.

From these applications, it is easy to visualise larger industrial scale applications. The food industry needs chilling as well as large buildings such as supermarkets, malls, hospitals and airports. On an even larger scale, so do processes such as the metal industry, pharmaceutical and chemicals all require chilling or cooling in addition to power and heat (steam or hot water). However, one significant industry, the one you use when calling to someone, that being IT and datacentres require a lot of cooling for their tens of thousands of servers.

To illustrate the size of the demand for this process, in EU 2.7% of all industrial energy consumption is used for cooling.

Image. The food industry needs chilling.

 

Why is the usage of chilling developing?

It should be no surprise to anyone, that our modern, ever developing lifestyle with computer, mobile communications and so on means that there has been a dramatic increase in the number of datacentres and thus also in cooling. As an example of other industries in need of cooling, the chilled food sector is constantly growing: it is growing at one of the fastest paces in this sector and already demands a big share of the whole food processing industry. For example, in UK, chilled foods account for 10% of all UK retail foods by value.

The countries with the highest cooling use are Germany (19%), Italy (15%), France (12%), Spain (10%), UK (7%), and the Netherlands (6%), representing together 68% of total process and space cooling in the EU.

 

How is cooling being used in industrial solutions?

Cooling can be achieved using several methods. Electric chillers are effective but they use the most expensive means of energy: electricity. In larger industrial units, such as cooling commercial buildings, absorption chillers are preferred. These chillers use heat to make cooling and are thus more economical when the cooling needs are large and/or the load profile constant.

Image. Large industrial absorption chiller.

Absorption chilling systems offer a number of advantages over conventional chilling systems and as such offer the most economically viable solution for reduced emissions and deliver cooling. The benefits of absorption chillers include:

  • They are heat operated – avoids expensive electrical drive
  • In combination with a turbine, cooling made this way reduces CO2 emissions as the total efficiency of the plant increases and no power is used for cooling.
  • No moving parts - reduced maintenance costs, long operational availability, noiseless operation
  • The refrigerant is only water – environmentally harmful refrigerant is not required

 

How Aurelia’s turbines can be used for cooling?

Aurelia’s turbines provide excess heat, that can be recovered by an absorption chiller and used for cooling.

Image. Aurelia's turbine installed to feed absorption chiller.

The temperature of the hot gas from the A400 turbine exhaust allows the application of a high efficiency, double-effect absorption chiller. In these installations, up to 86% of the thermal output of the cogeneration plant is thereby converted to chilled water. This type of plant are called Combined Cooling and Power (CCP) and there are a number of benefits to CCP including:

  • Increased energy efficiency
  • Reduced peak seasonal electrical use
  • Significant reduction in environmental impact
  • Improved building energy efficiency rating such as Energy Star in the UK and LEED in USA
  • Increased energy security

 

Combined Cooling Heat and Power

The usage of absorption chillers is widely used for air conditioning. It is particularly versatile, in cold times it can be turned off and the heat used can be used to keep the building warm. Sometimes the heating and cooling are also needed same time – cooling for building and less amount of heating to provide warm water to be used. These installations are called Combined Cooling Heat and Power (CCHP). Sometimes they are known as trigeneration, as the process where the heat energy produced by a Combined Heat and Power (CHP) plant is utilised to generate chilled water for chilling or air conditioning.

Image. CCHP installation with Aurelia turbine.

Combining a CHP with an absorption chiller allows utilisation heat for cooling and heating: and simultaneously in some cases. The hot turbine exhaust gas serves as drive energy for the absorption chiller and the heat exchanger; they are being directed as needed by the heat load. In this way, the annual capacity utilisation and the overall efficiency of the cogeneration plant can be increased significantly.

There are a number of benefits to CCHP including:

  • Increased energy efficiency
  • Reduced fuel energy costs
  • Reduced peak seasonal electrical use
  • Significant reduction in environmental impact
  • Improved building energy efficiency rating such as Energy Star and LEED in USA
  • Increased energy security