| Summary: | RES Master´s Thesis Verkefnið er unnið í tengslum við Háskóla Íslands og Háskólann á Akureyri Single stage absorption chillers (water/lithium bromide) can operate using low grade heat, thus single stage absorption chillers can operate using low temperature geothermal resources. An EES computer model was written for a single stage absorption chiller based on overall heat transfer coefficients, mass flows, salt balances, energy balances and other assumptions. The single stage model was calibrated with well known and available data from US and Japanese manufacturers. The system was considered to work in hot and humid climates like those in Abu Dhabi and Shanghai. The results show that when cooling water is 28 °C hot the initial and annual total cost is high. However, as cooling water temperature decreases, the initial and annual total cost decreases sharply (when cooling water is at 20°C the reduction is around 35% of the total annual cost). The results show a great influence of cold and hot water on the performance and total annual cost of absorption chillers. The second part of the computer model contains a Total Equivalent Warming Impact (TEWI) analysis. TEWI considers both the direct refrigerant effects and the primary energy impact on equivalent carbon dioxide (CO2) emissions. Competing technologies are vapour–compression and gas cycles. The results show some recommendations for absorption system diversification to reduce the Total Equivalent Warming Impact. The results also show that absorption hot water chillers have the lowest contribution to Global Warming (TEWI).
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