Workshop on energy efficiency opportunities while

Transcript:Workshop on energy efficiency opportunities while:
Workshop on energy efficiency opportunities while phasing-down HFCs Cooling Efficiency: technologies Presentation by Ray Gluckman July 9th 2018, Vienna Presentation Contents Scope for energy efficiency improvements Understanding key efficiency issues efficiency: a step-by-step approach Some examples illustrating: the excellent potential for efficiency improvements impact on capital costs impact of refrigerant selection Significant Potential to Improve Efficiency Achieving the technical potential there are plenty of opportunities to improve efficiency what is preventing better uptake of the potential? Some Key Principles during next two sessions we will see many examples of: efficiency improvements related to new equipment (Session II) efficiency improvements related to existing equipment (Session III) to help understand efficiency opportunities what are the key design and operational factors that influence energy use? let’s start by comparing a refrigeration system with moving a weight…… Moving a weight downhill is easy Moving it back up the hill requires energy Moving it back up the hill requires energy The energy required depends on: The size of the weight, W The height difference, d (the “vertical lift”) Practical factors e.g. roughness of the ground W d Refrigeration: moving heat on a “thermodynamic mountain” hotter Temperature colder Weight = a quantity of heat we need to move Vertical lift = temperature we need to move it through = “temperature lift” If a colder heat sink is available, cooling is free (heat “rolls downhill”) hotter Temperature colder - not realistic or sustainable! But, always worth checking for “free cooling” options some good possibilities e.g. data centre cooling, especially if located in cool climates food factories – hot product pre-cooling after cooking cold process streams that need heating e.g. boiling liquid methane at LNG terminals but less helpful for “mainstream” RAC applications e.g. domestic refrigerators bulk storage and retailing of chilled or frozen food room air-conditioning in hot countries Most RACHP applications – heat has to move “uphill” Most RACHP applications – heat has to move “uphill” How is the heat moved “uphill”? How is the heat moved “uphill”? How is the heat moved “uphill”? How is the heat moved “uphill”? Evaporating temperature Te must be lower than product temperature Condensing temperature Tc must be higher than the available coolant Why is temperature lift so important? RACHP efficiency is VERY sensitive to temperature lift just 1 degree C of extra lift: typically leads to 2% to 4% increase in energy consumption it is very easy to create