A holistic approach that includes process design, heat recovery design and building heating infrastructure design is crucial to optimizing a facility's efficiency. Ed Kiser, director of engineering and team leader for energy efficiency studies at Worthington Energy Innovations, Fremont, OH, is instrumental in the development, testing and application of the "liquid chimney" for heat recovery and carbon reduction installations as well as developing the sequence of operation control logic to optimize the energy efficiency of Worthington’s previously installed and new energy systems. He offered his insight to Baking & Snack's Operations Update readers.
Baking & Snack: How can a bakery or snack food operation effectively identify efficiency and heat recovery opportunities?
Ed Kiser: By using computational process energy models to quantify where every btu is transferred. Quantifying the energy flows leaving the process will identify the efficiency and heat recovery opportunities. The detail needed to generate a model depends on the complexity of the process and the available data. It is critical to validate all energy model calculations with actual performance data.
How can a company maximize its heat recovery potential?
Building energy models identify heat rejection, or heat recovery sources, and heating loads. The form of the heat rejection dictates the temperature and form of potential heat recovery options. The heat recovery design must provide energy in a form that is useful by another system.
What are the key considerations to keep in mind while optimizing heat recovery?
Great detail is required in the energy model to accurately project the heat recovery opportunity. The design has to generate heat in useful form or temperature when it is needed and ensure that all recovered heat has a home.
Please explain the design and purpose of a liquid chimney.
The liquid chimney is a direct contact gas to water heat exchanger. The direct contact design allows very high exchanger effectiveness. The high effectiveness allows the liquid chimney to transfer both sensible and latent heat from process exhaust to water. The liquid chimney is capable of achieving heat transfer efficiencies of up to 98%.