Wind energy heat utilization is a revolutionary clean energy technology that can replace coal-fired boilers for heating and improve wind energy consumption. On the basis of summarizing and analyzing the current research situation of wind energy and heat utilization systems at home and abroad, the National Energy Wind Power Blade R & D (Experimental) Center headed by Xu Jianzhong, academician of the Chinese Academy of Sciences, put forward the innovative concept of “wind and heat generating units†based on the intersection of wind energy utilization and thermodynamics. The unit uses wind energy as the driving force and directly converts wind energy into heat energy without going through the power generation link. Due to the reduced energy conversion loss of wind energy and electrical energy, the system cost is reduced and the system efficiency is greatly improved. The economic index is far superior to the current mainstream Clean energy heating / cooling technology. The structure of the cabin of the wind-heat unit is shown in Figure 1. Focusing on the innovative concept of "wind-heating unit", the main progress has been made in the following aspects:
Based on the wind turbine simulation system, a semi-physical simulation experiment platform and a calculation simulation platform for the wind-heating unit are built, as shown in FIG. 2. The servo motor is controlled by the wind turbine simulation system, which can simulate the power output of the wind turbine under different working conditions, and then the servo motor is used as the driving power to adjust the input power change of the heat pump. Variation of heating performance coefficient COP (heating capacity / mechanical energy) of wind-heating units under different working conditions. On the other hand, the simulation calculation model of the wind-heat unit is built. Figure 3 shows the comparison result of the measured and simulated values ​​of the COP of the heat pump unit. It can be seen that the experimental platform verifies the reliability of the simulation model of the wind-heat unit.
Based on the Aerodyn / FAST wind turbine simulation platform developed by the American Renewable Energy Laboratory (NREL), combined with the BEM theory and the open compressor model, a 1.5MW wind-heating unit simulation model was constructed. Based on this model, the performance curves at different wind speeds and the operating rules under typical operating conditions are obtained. Figure 4 shows the wind energy utilization coefficient Cp (mechanical energy / wind energy) and primary energy utilization Cp × COP (heating capacity / wind energy) of the wind-heating unit. It can be concluded that the Cp of the wind-heating unit decreases first and then increases. It reached a peak value of 0.4627, and then gradually decreased; the primary energy utilization rate Cp × COP and Cp of the wind-heating unit showed a similar change rule, but its peak value moved back to a high wind speed, and the peak value reached 1.9363 at a wind speed of 8.54 m / s. Figure 5 shows the changes in the mechanical energy and heating capacity of a 1.5MW wind-heating unit applied to the Huangdicheng town in Zhuolu, Zhangjiakou in winter. The heating value of this unit varies up to 5.34MW over time, and the average heating power is about 3.0MW , Can meet the heating needs of 50,000 square meters of buildings.
In order to better promote the advancement of wind energy heat utilization towards industrialization, with the special support of the Class A strategic pilot technology of the Chinese Academy of Sciences, after more than a year of key technical research and machine optimization, the team completed a 100-kilowatt wind in December 2019 The prototype of the heat generating unit was developed and planned to be completed in 2020 in Huangdicheng Town, Zhuolu County, Hebei Province, to provide a 5000-square-meter building for a hotel with a cold and heat source. The wind-heat unit uses a soil source as a low-temperature heat source for heating. Under the circumstances, 50 ~ 60 ℃ hot water will be produced, and the heating COP can reach more than 3.5 (see Figure 6 for details). This demonstration project will lay a solid foundation for the follow-up industrialization of wind-heating units.
Figure 1 Structure diagram of the nacelle of the wind-heat unit
Figure 2 Photos of the experimental platform for performance testing of air-heating units
Figure 3 COP measured and simulated values ​​of heat pump unit
Figure 4 Wind energy utilization factor and primary energy utilization rate of wind-heating units
Figure 5 Changes in mechanical energy and heating capacity under typical working conditions in winter
Figure 6 Flow chart of 100kW wind-heating unit heating and cooling system in Huangdicheng Town
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