Carbon Foot Print Reduction of Church Farm Brewery through Converting the Cooling Chiller Waste Heat to Electricity – Feasibility Study


Church Farm Brewery is a family run craft brewery located on the family farm on the outskirts of Warwick. During the fermentation process, cooling glycol is pumped around a series of heat exchange panels on the beer tanks to cool them to 2OC. An electrically driven vapour compression chiller with a maximum cooling capacity of 40kW is used to deliver this cooling requirement.

This chiller is an air cooled where the heat of condensation of 50-60 kW is rejected to the atmosphere (depending on weather conditions). Therefore, this project aims to carry out a feasibility study to investigate the potential of recovering this rejected heat and converting it to electricity.

This can be achieved through assessing the feasibility of integrating an Organic Rankine cycle (ORC) to the chiller where the chiller condenser rejected heat will be supplied to the evaporator of the ORC. The evaporated ORC fluid will be used to drive an expander coupled to an electric generator for producing electricity.

This generated electricity (~10kW) can be used to reduce the energy consumption of Church Farm Brewery leading to reduction in its carbon foot print. Every of electricity saved will reduce CO2 emission by 0.3kge CO2. Therefore, this saved 10kW of electricity will produce a reduction of 3kge CO2 per hour. Based on Church Farm fermentation process of 2-4 days per week (48 – 96 hours), leading to up to 14,976 kgeCO2 saved annually.

Project Objectives

  1. Measurement and monitoring of the chiller performance in terms of rate of heat released, electricity consumption, operating temperatures particularly at the condenser where heat is rejected. (Temperature sensors will be purchased and installed on the system at appropriate points).
  2. Analysis of the measured data to evaluate the amount of heat available for recovery and its temperature.
  3. Develop a thermal model the chiller and validate it using the measured data.
  4. Develop a thermal model of an Organic Rankine cycle that can exploit the rejected heat from the chiller to produce electricity.
  5. Integrate the two models to predict the best operating conditions