| It is necessary to develop new and renewable energy for energy structure optimization and environmental protection in China. As a renewable energy technology, seawater source heat pump system (SWHP) have been paid more and more attention at home. However, before the technology is worth popularizing and applying in China, a comprehensive evaluation should be made to aid in making decisions. During the evaluation, no only the energy consumption in the operational phase, but also the environmental impact of construction process and water body should be analyzed. Consequently, this thesis aims to resolve these difficulties as the operation and construction sequence.First Annual energy consumption of two SWHP projects is analyzed. In the literature, district cooling system is designed to maintain a relatively constant delta-T, the difference between return and supply chilled water temperature. But in almost every real chiller plant, delta-T falls well short of design levels. The result is higher pump and chiller energy usage. The component models representing typical building load profiles, chilled water△T, heat pump, pumps and component control algorithm are studied. The results show that load characteristic and cooling radius have remarkable effects on reducing energy consumption.Second this thesis adopts two-dimensional depth-averaged model, which is used to simulate the flow field and the temperature field of thermal discharge in middle and far-field based on two demonstration SWHP projects. The analysis result shows that the temperature elevation is far less than the grade-one sea water quality of China. The heated discharge from the two heat pump plants will not bring remarkable thermal effect for the natural receiving water. To study the mutual interference between neighboring intake and outlet, 3-D temperature variation in the small field near the outlet is simulated using near filed model. The results show that there could be local hotspots where the water temperature exceeds than the permissible limit (4℃). Damages of thermal discharges to ecosystem quality are expressed as percentage of species disappeared in a certain area, due to the thermal pollution.Third, this thesis presents an environmental assessment of the construction of seawater source heat pump system. This includes the following main sections: district heating and cooling pipe netwoks and main equipments. A basic of database of energy and materials consumption of the construction is collected, sorted based on the national unified budget quota of installing engineering. The total environment load of district heating and cooling pipes is analyzed using the end-point damage method. For reasons of lack of data, it is difficult to assess the environmental impacts of main equipments. Using input-output data for embodied energy and extrapolate method, the environmental impact of equipments was calculated.Finally, this thesis presents a new method to evaluate economic, energy efficiency and environmental impact—Net environmental cost (NEC), which embody environmental costs in the economic accounting under the current conditions. NEC indicator is calculated based on Xiaoping Dao SWHP and Xinghai bay SWHP projects. Those works can be a Decision-Making Guide for Local government.
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