Intelligent Hands Off Heatpump Systems
W L Douglas and Sons are based near Berwick-upon-Tweed in North Northumberland. This business has seen rapid growth in the last several years resulting in a Grain Drying requirement of some 25,000 tonnes. Partner Ian Douglas approached the Calibrate Energy Engineering team to look at ways they could speed up and streamline their Grain Drying and cooling process. It was agreed that Calibrate’s 1mW Heatpump HeatChill system seemed like the perfect fit for their 40t/hr Continuous Grain Drying system. A bespoke Control System remotely manages this system enabling The Douglas’ to have a ‘hands off’ approach as well as enabling real time tariff generation and power consumption readings.
Having 22 years of industrial refrigeration experience in the chilling sector, and 12 years as a Heatpump Business owner, the Calibrate Technical Director Shane McDonald put together an outline plan to pre-heat the air onto the burners to 45°c, whilst also using the free chilling to bring the grain 8-12°c below ambient prior to storage. This worked to reduce fossil fuel usage, derive a high 20 year RHI tariff and also sped up the throughput by chilling the grain after drying. With the further benefit of little, or no mechanical ventilation within the storage sheds afterwards.
- £2,609,25 of income and savings generated with the 20 year Government Tariff
- A 4-5 year pay back on the 20 year scheme
- 45-50°c at 400% heating efficiency
- 1°c at 325% chilling efficiency
- Total energy efficiency of 725%
This is the first site of its kind in the UK to have a Simultaneous Heating and Chilling system. Plans are being made to further utilise the 900kw of 1°c chilled water now available onsite, with ideas such as free chilled storage, free dairy milk chilling and free potato chilling as options. A grid application has also been submitted to install a 250kW Solar system to further utilise Calibrates unique inhouse developed Export Management system to vary the power usage of the Heatpumps from 10% to 100% depending on the level of power generation available, meaning no power input cost when the sun is shining, further reducing the payback and grid reliance.