Analysis On Life Cycle Cost Of Surface Water Heat Pump System

The surface water heat pump technology has been increasingly applied in China. However, the promotion of this technology also faces the difficulty of technology economy optimizing. The present construction party mainly concerns about the one-time investment but not much about reclaiming the operating cost. On the other hand, the varieties of factors which may influence the surface water heat pump system also influence the assessment of the later stage operating cost. See from the external environment, with universal rise of the energy price as well as the severity of the environmental problems, the high energy consumption make people obliged to consider the life cycle cost theory. The life cycle cost analysis leads the decision maker and designers to consider the capital costs and operating cost of air-conditioning system consciously and comprehensively. In the decision stage of the scheme, they can choose the best plan according to the principle of minimal LCC. This paper will apply the idea of LCC to analyze and evaluate the surface water heat pump system as well as analyze the critical factor influencing its costs.The theory of LCC to the surface water heat pump system will be introduced to analyze the constitutional system of its LCC and the formula of calculating LCC will be provided. Besides, this paper will do qualitative and quantitative analysis of the factors such as discount rate, life cycle and rate of inflation which may influence the LCC. Furthermore, this paper will set the conventional air-conditioning system as the reference object. By applying the balance analytical process to initial cost and operating cost of the constitutional system of the surface water heat pump system, two conclusions will be reached: one is the limit value of its operating cost under different conditions, the other is the limit value of its initial cost with respect to the conventional air-conditioning system.Through analyzing the annual air-conditioning dynamic load of three typical public buildings—office building, emporium and hotel in Chongqing by applying the DOE energy analytical software on the basis of the cooling load time frequency gained through simulation, the method of calculating the annual operating power consumption of the system will be established by using the energy consumption model of surface water heat pump system. Through calculating the LCC of the three typical public buildings—office building, emporium and hotel in Chongqing respectively by applying the surface water heat pump system on the basis of the rated conditions of the specific heat pump unit, doing comparative analysis by using conventional air-conditioning system as a reference object, analyzing the influence of the water intake temperature, the water intake way and the pump's operating mode of the surface water heat pump system on LCC, following conclusions are reached: the water intake in summer will have more obvious influence on LCC than intake in winter, and in a specific water intake temperature its LCC value is higher than the conventional air-conditioning system in the whole life cycle through it can save more energy than the conventional air-conditioning system in a specific operation condition; by setting infiltration water intake method as an example and different investment cost scheme as research object, and through quantitative analysis this paper reaches an conclusion that a proper water intake temperature and controlling the initial cost of water intake system can make a proper life cycle cost; the paper will also analyze the effect of the frequency conversion and steady frequency operation of the water-intake pump on the annual operating energy consumption of the surface water heat pump system, the extent of its influence on LCC will also be gained.The sensitivity analysis will be introduced on account of the uncertainty factors in LCC analysis and through analyzing the LCC of the surface water heat pump system by applying the method of the single factor sensitivity analysis, the most sensitive factor—electricity price and initial cost will be gained as well as the extent of influence of the variation of these two factor on the result of decision when making decision.At last, the paper set a practical surface water heat pump project as an example and make a comparative analysis to the conventional air-conditioning system by using the calculating method of water intake based on the purpose of the reclaimed water of the water intake project; Besides, the paper evaluate the LCC of its surface water heat pump system by making use of the actual data of its operating condition in summer and make a comparative analysis to the theoretical calculation value.The paper introduce the theory of LCC to the surface water heat pump system to analyze variety of factors which may influence the value of LCC and do quantitative analysis of the LCC value under different conditions influenced by each factor. In addition, this paper will establish a set of feasible LCC calculating process, and evaluating and analyzing method of the surface water heat pump system based on the balance analysis methodology. All these will make a foundation of economic theory to gradually promote the development of the surface water heat pump system.