scholarly journals Effects of Thermal Discharge from Coastal Nuclear Power Plants and Thermal Power Plants on the Thermocline Characteristics in Sea Areas with Different Tidal Dynamics

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2577 ◽  
Author(s):  
Faming Huang ◽  
Jie Lin ◽  
Binxin Zheng

The thermal discharge from coastal nuclear power plants and thermal power plants (CNATPP) not only increases the water temperature, but it also stratifies the seawater. Comprehending the characteristics of stratification that is caused by thermal discharge constitutes the basis for developing a comprehensive understanding of how thermal discharge affects marine organisms. The spatial and temporal characteristics of seawater stratification induced by thermal discharge were analyzed on the basis of measured data while using two study areas with different tidal dynamics as examples. The results showed the following. (1) Thermal discharge influenced the area within 3 km of the outlet. (2) In the East China Sea (which has strong tidal dynamics), the most significant stratification occurred 0.5 km–1.0 km from the outlet; however, in the South China Sea (which has weak tidal dynamics), the degree of stratification decreased with increasing distance from the outlet. (3) In the East China Sea (i.e., strong tidal dynamics), the depth of the thermocline during ebb tide gradually moved upward, while that during flood tide gradually moved downward, and the opposite was observed in the South China Sea (i.e., weak tidal dynamics). Finally, (4) the thermocline that was caused by thermal discharge mostly occurred at water depths above 7 m.

Author(s):  
Alexey Dragunov ◽  
Eugene Saltanov ◽  
Igor Pioro ◽  
Pavel Kirillov ◽  
Romney Duffey

It is well known that the electrical-power generation is the key factor for advances in any other industries, agriculture and level of living. In general, electrical energy can be generated by: 1) non-renewable-energy sources such as coal, natural gas, oil, and nuclear; and 2) renewable-energy sources such as hydro, wind, solar, biomass, geothermal and marine. However, the main sources for electrical-energy generation are: 1) thermal - primary coal and secondary natural gas; 2) “large” hydro and 3) nuclear. The rest of the energy sources might have visible impact just in some countries. Modern advanced thermal power plants have reached very high thermal efficiencies (55–62%). In spite of that they are still the largest emitters of carbon dioxide into atmosphere. Due to that, reliable non-fossil-fuel energy generation, such as nuclear power, becomes more and more attractive. However, current Nuclear Power Plants (NPPs) are way behind by thermal efficiency (30–42%) compared to that of advanced thermal power plants. Therefore, it is important to consider various ways to enhance thermal efficiency of NPPs. The paper presents comparison of thermodynamic cycles and layouts of modern NPPs and discusses ways to improve their thermal efficiencies.


Author(s):  
Igor L. Pioro

Supercritical Fluids (SCFs) have unique thermophyscial properties and heat-transfer characteristics, which make them very attractive for use in power industry. In this chapter, specifics of thermophysical properties and heat transfer of SCFs such as water, carbon dioxide, and helium are considered and discussed. Also, particularities of heat transfer at Supercritical Pressures (SCPs) are presented, and the most accurate heat-transfer correlations are listed. Supercritical Water (SCW) is widely used as the working fluid in the SCP Rankine “steam”-turbine cycle in fossil-fuel thermal power plants. This increase in thermal efficiency is possible by application of high-temperature reactors and power cycles. Currently, six concepts of Generation-IV reactors are being developed, with coolant outlet temperatures of 500°C~1000°C. SCFs will be used as coolants (helium in GFRs and VHTRs, and SCW in SCWRs) and/or working fluids in power cycles (helium, mixture of nitrogen (80%) and helium (20%), nitrogen and carbon dioxide in Brayton gas-turbine cycles, and SCW/“steam” in Rankine cycle).


Author(s):  
Tuan Quoc Banh

The unilateral establishment of the Air Defense Identification Zone (ADIZ) on the East China Sea along with a variety of unilateral moves to confirm its illegitimate sovereignty on the South China. Indicating that China is preparing necessary conditions to establish an ADIZ on the South China Sea. As a country with interests associated with the South China Sea in the region, Vietnam should be proactive in all possible future situations. As a result, Vietnam should conduct research and prepare conditions to establish an ADIZ on the South China Sea so as to protect national sovereignty on the South China Sea prior to the unilateral imposition by China.


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