Waste heat driven absorption/vapor-compression cascade refrigeration system for megawatt scale, high-flux, low-temperature cooling

A novel cascaded absorption/vapor-compression cycle with a high temperature lift for a naval ship application was conceptualized and analyzed. A single-effect LiBr-H(2)O absorption cycle and a subcritical CO(2) vapor-compression cycle were coupled together to provide low-temperature refrigerant (-40 degrees C) for high heat flux electronics applications, medium-temperature refrigerant (5 degrees C) for space conditioning and other low heat flux applications, and as an auxiliary benefit, provide medium-temperature heat rejection (similar to 48 degrees C) for water heating applications. A thermodynamic model was developed to analyze the performance of the cascaded system, and parametric analyses were conducted to estimate the performance of the system over a range of operating conditions. The performance of the cascaded system was also compared with an equivalent two-stage vapor-compression cycle. This cycle was found to exhibit very high COPs over a wide range of operating conditions and when compared to an equivalent vapor-compression system, was found to avoid up to 31% electricity demand. (C) 2011 Elsevier Ltd and IIR. All rights reserved.