Performance evaluation of distributed energy system integrating photovoltaic, ground source heat pump, and natural gas-based CCHP

Abstract This paper analyzes the energy saving effect and optimal operation of the integrated park type energy system. The park type integrated energy system includes photovoltaic power generation system, ground source heat pump system, solar air conditioning system, regenerative electric boiler system and solar hot water system and so on. The energy saving benefit calculation model of each subsystem is established, and according to the operation history data of each subsystem, the calculation results of each subsystem are analyzed. It shows that: The energy saving income of photovoltaic power generation system is 734,200 yuan/year. The main revenue comes from the second and third quarters, during which it should pay attention to the maintenance of photovoltaic modules to ensure the maximum energy saving benefit. The energy saving income of ground source heat pump system in summer is 155,900 yuan/year, and the energy saving effect is not significant. It can cooperate with traditional units for cooling in summer. The heating in winter in the park is provided by ground source heat pump system, regenerative electric boiler system and solar energy air conditioning system. Its energy saving benefit is 3.995 million yuan/year which is the main source of energy saving income in the park, with remarkable energy saving effect.

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Performance Evaluation of a Vertical U-Tube Ground Heat Exchanger Using a Numerical Simulation Approach

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.724-725.909 ◽

2013 ◽

Vol 724-725 ◽

pp. 909-915

Author(s):

Ping Fang Hu ◽

Zhong Yi Yu ◽

Fei Lei ◽

Na Zhu ◽

Qi Ming Sun ◽

...

Keyword(s):

Heat Transfer ◽

Performance Evaluation ◽

Heat Exchanger ◽

Heat Pump ◽

Heat Transfer Process ◽

Working Fluid ◽

Outlet Temperature ◽

Ground Heat Exchanger ◽

Ground Source Heat Pump ◽

Ground Source

A vertical U-tube ground heat exchanger can be utilized to exchange heat with the soil in ground source heat pump systems. The outlet temperature of the working fluid through the U-tube not only accounts for heat transfer capacity of a ground heat exchanger, but also greatly affects the operational efficiency of heat pump units, which is an important characteristic parameter of heat transfer process. It is quantified by defining a thermal effectiveness coefficient. The performance evaluation is performed with a three dimensional numerical model using a finite volume technique. A dynamic simulation was conducted to analyze the thermal effectiveness as a function of soil thermal properties, backfill material properties, separation distance between the two tube legs, borehole depth and flow velocity of the working fluid. The influence of important characteristic parameters on the heat transfer performance of vertical U-tube ground heat exchangers is investigated, which may provide the references for the design of ground source heat pump systems in practice.

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