| The development and utilization of hydraulic electric generating gets more and more attention from people as it is a kind of renewable and clean energy. And our country is also in the peak of hydropower station construction and development now. Due to factors such as geographic conditions, many large and medium sized hydropower stations will be buried deep underground. And the volume of the underground powerhouse is usually huge, the thermal and humid environment is also complicated and difficult to control. It makes a huge energy consumption of HVAC system. This paper proposes the concept of comprehensive efficiency to evaluate the energy efficiency of the HVAC system of the underground hydropower station and the distribution of the thermal and humid environment.The definition of the comprehensive efficiency of the HVAC system of the underground hydropower station is the ratio of the thermal-humidity load to maintain a suitable thermal and humid environment of the underground hydropower station and the power consumption of the HVAC system. And the improvement of the comprehensive efficiency must be on the basis of meeting the requirements of the thermal and humid environment of the underground hydropower station.First, this paper elaborates the main design conditions of the HVAC system of the underground hydropower station. It includes the structure of the underground powerhouse, indoor and outdoor air computation parameter, the character of envelop enclosure, thermal-humidity load of the underground powerhouse, the design of HVAC system and the device configuration information. And analyses the effect of those design conditions on the comprehensive efficiency.Then the comprehensive efficiency of different working conditions of HVAC system of underground hydropower station is quite different. Due to the particularity of hydropower station, the time to test the hydropower station is very limited. It is usually taking part working conditions test for the HVAC system of underground hydropower station, not all working conditions as so far. But in order to accurately reflect the energy efficiency and the thermal and humid environment of the whole HVAC system of underground hydropower station, we need to ensure the typical working condition to test that can represents the working condition of the whole HVAC system of underground hydropower station. This paper defines the typical working condition of the HVAC system of underground hydropower station form the outdoor meteorological parameters, the unit running situation of the hydropower station and the operation modes of the HVAC system of underground hydropower station. The test of the comprehensive efficiency of the HVAC system of the underground hydropower station should be doing in Summer,June to September. the outdoor meteorological parameters should be close to the design parameters, the unit running is at the peak hours. And the calculation of the comprehensive efficiency should take the air parameters of the end of the intakes to the fresh air parameters in order to reducing the influence of the change of outdoor meteorological parameters. At the same time, we choose the whole operation condition, half operation condition of the HVAC system, and the ventilation condition to test.This paper defines the testing contents and specific method of the comprehensive efficiency of the HVAC system of underground hydropower station by analyzing of the test contents of the HVAC engineering of civil building and characteristics of the underground hydropower station. The amount of testing is too many and testing process is too cumbersome if we arrange the measuring point according to current specification when we test the thermal and humid environment of the underground hydropower station. In this paper, we analysis the measuring point arranging for large space powerhouse of the underground hydropower station based on the measuring point arranging for generator floor of the underground hydropower station. In this paper, we put forward the simplified point layout scheme of the generator layer underground hydropower station by summarizing the characteristics of the thermal and humid environment of the generator layer. The thermal and humid environment test of generator layer should be arranged in every generator unit and erection bay. We could decorate five test points on the generator cover plate and the four corners in every generator unit. The test points in the erection bay could be reduced properly according to the density of the test points in every generator unit, and the test points in the generator unit which is close to the erection bay could increase the test points. The result of this simplified point layout scheme is basically identical with actual situation, so the simplified point layout scheme can meet the test requirements.And we tested the comprehensive efficiency of the HVAC system of Yixin pumped-storage power station, Jiangsu and Jiemian underground hydropower station, Fujian according to the above method. The value of the comprehensive efficiency of the Yixin underground hydropower station HVAC system is between 1.94 ~ 2.29 regardless of the cooling capacity of the Underground intakes. The value of the comprehensive efficiency is between 3.36 ~ 4.11 taking into account the cooling capacity of the Underground intakes. And the thermal and humid environment is pretty well during the test. The value of the comprehensive efficiency of the Jiemian pumped-storage power station HVAC system is between 3.48 ~ 4.26 during the different ventilation air conditioning system working conditions. But the humidity during the test is significantly higher than the relevant standard specification requirements.Comparing with evaluation system of civil building HVAC system, this paper puts forward that the evaluation of the HVAC system of underground hydropower station should be conducted in three levels, they are the coefficient evaluation of ventilation and air conditioning equipment, system design energy efficiency, and system running energy efficiency. In this paper, we statistics the design energy efficiency ratio of the HVAC system of some underground hydropower stations, the value is between 2.29~2.58. And we analysis how to test the season energy efficiency ratio of the HVAC system of the underground hydropower station based on the testing content and testing method of the HVAC system of the underground hydropower station on typical working condition. |
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