scholarly journals Node Temperature of the Coupled High-Low Energy Grade Flus Gas Waste Heat Recovery System

Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 248 ◽  
Author(s):  
Jiayou Liu ◽  
Fengzhong Sun
Keyword(s):  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Power Plants ◽  
Waste Heat ◽  
Low Energy ◽  
Gas Temperature ◽  
Waste Heat Recovery System ◽  
Recovery System ◽  
Optimal Node ◽  
Exergy Balance

Coupled high-low energy grade flus gas waste heat recovery systems (CWHRS) have been applied in power plants to improve unit efficiency. In this study, to evaluate the rationality of waste heat recovery, the energy-grade balance coefficient (EBC) of the CWHRS was derived using the theory of heat balance, exergy balance and energy grade balance. The inlet flue gas temperature (IFT) of the low-temperature economizer was defined as the node temperature of the CWHRS. The optimal node temperature (ONT) was optimal when the absolute value of the EBC was the smallest. The exergy efficiency and EBC of the system installed on a supercritical 600 MW unit were calculated and the result shows that the ONT of the system was about 115 °C, the ONT decreased from about 135 °C to about 113 °C when the IFT increased from 335 °C to 380 °C and the ONT decreased from about 144 °C to about 113 °C when the inlet air temperature increased from −10 °C to 35 °C. The node temperature is recommended as an adjusting parameter of CWHRS to ensure the effect of waste heat recovery.

Feasibility Study of a Supercritical Cycle as a Waste Heat Recovery System

2013 ◽  
Author(s):  
Antonio Agresta ◽  
Antonella Ingenito ◽  
Roberto Andriani ◽  
Fausto Gamma
Keyword(s):  
Power Systems ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Power Plants ◽  
Energy Savings ◽  
Waste Heat ◽  
Rankine Cycle ◽  
Waste Heat Recovery System ◽  
Recovery System ◽  
Organic Fluids

Following the increasing interest of aero-naval industry to design and build systems that might provide fuel and energy savings, this study wants to point out the possibility to produce an increase in the power output from the prime mover propulsion systems of aircrafts. The complexity of using steam heat recovery systems, as well as the lower expected cycle efficiencies, temperature limitations, toxicity, material compatibilities, and/or costs of organic fluids in Rankine cycle power systems, precludes their consideration as a solution to power improvement for this application in turboprop engines. The power improvement system must also comply with the space constraints inherent with onboard power plants, as well as the interest to be economical with respect to the cost of the power recovery system compared to the fuel that can be saved per flight exercise. A waste heat recovery application of the CO2 supercritical cycle will culminate in the sizing of the major components.

Thermo-Economic Optimization on the Waste Heat Recovery System of SCO2 Coal-Fired Power Plants

2020 ◽  
Author(s):  
Ruiqiang Sun ◽  
Kaixuang Yang ◽  
Ming Liu ◽  
Junjie Yan
Keyword(s):  
Power Plant ◽  
Low Temperature ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Power Plants ◽  
Waste Heat ◽  
Waste Heat Recovery System ◽  
Recovery System ◽  
Heat Recovery System ◽  
Plant Efficiency

Abstract The temperature of SCO2 fed to the boiler in SCO2 coal-fired power plants is relatively high, ∼500 °C. It leads to high boiler exhaust temperature, which is ∼120 °C according to previous studies. Waste heat recovery from low temperature fluegas in SCO2 coal-fired power plants is a key issue to be addressed to enhance power plant efficiency and electrostatic precipitator performance. Therefore, systems of waste heat recovery from low-temperature fluegas were proposed in this study. To evaluate the economic performances of the proposed systems and obtain the best system configurations, economic and thermodynamic models were developed. Moreover, multi-parameter optimization model based on Genetic Algorithm was developed. The waste heat recovery system is proposed and optimized by considering coupling and matching of the air preheating process, heat regenerative process and fluegas cooling process. With a 1000MW SCO2 coal-fired power plant as the reference case, thermodynamic and economic analyses were carried out. Results show that when the low temperature economizer is integrated together with the main compressor intercooling and flue bypass ahead the air-preheater, the temperature of exhaust fluegas can be decreased to ∼95 °C and the power plant efficiency can be enhanced by 1.39%-pts compared with basic system. Through the economic model analysis, the system levelized cost of electricity is 0.04158 $ kW−1 h−1.

scholarly journals Experimental Study on Operation Regulation of a Coupled High–Low Energy Flue Gas Waste Heat Recovery System Based on Exhaust Gas Temperature Control

Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 706 ◽  
Author(s):  
Jiayou Liu ◽  
Fengzhong Sun
Keyword(s):  
Flue Gas ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Gas Flow ◽  
Waste Heat ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Waste Heat Recovery System ◽  
Recovery System ◽  
Exhaust Gas Temperature

Controlling the exhaust gas temperature (EGT) of coal–fired boilers at a reasonable value is beneficial to ensuring unit efficiency and preventing acid corrosion and fouling of tail heating surfaces in power plants. To obtain the operation regulation of coupled high–low energy flue gas waste heat recovery system (CWHRS) under a given EGT, experimental equipment was designed and built. Experiments were carried out to maintain the exhaust gas temperature under different flue gas flow, flue gas temperature and air temperature conditions. As the flue gas flows, the flue gas temperatures and air temperatures increased, and the bypass flue gas flow proportions or the water flows of the additional economizer were increased to maintain the EGT at about 85 °C. An improved low temperature economizer (LTE) and front located air heater (FAH) system were put forward. As the flow of the crossover pipe increased, the EGT and the inlet water temperature of the LTE increased. As the flow of the circulating loop increased, the EGT and the inlet water temperature of the LTE decreased. Operation regulations of LTE–FAH system under four cases were given. The operation regulations of CWHRS and LTE–FAH system can provide references for power plant operation.

A novel flue gas waste heat recovery system for coal-fired ultra-supercritical power plants

2014 ◽  
Vol 67 (1-2) ◽  
pp. 240-249 ◽  
Author(s):  
Gang Xu ◽  
Cheng Xu ◽  
Yongping Yang ◽  
Yaxiong Fang ◽  
Yuanyuan Li ◽  
...  
Keyword(s):  
Flue Gas ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Power Plants ◽  
Waste Heat ◽  
Waste Heat Recovery System ◽  
Recovery System ◽  
Heat Recovery System

ANALYSIS ON THE EFFECT OF NANO PARTICLES IN WASTE HEAT RECOVERY SYSTEM USING HEAT PIPES BY RSM

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Gunabal S
Keyword(s):  
Response Surface Methodology ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Heat Pipes ◽  
Filling Ratio ◽  
Nano Particles ◽  
Waste Heat Recovery System ◽  
Recovery System ◽  
Heat Recovery System

Waste heat recovery systems are used to recover the waste heat in all possible ways. It saves the energy and reduces the man power and materials. Heat pipes have the ability to improve the effectiveness of waste heat recovery system. The present investigation focuses to recover the heat from Heating, Ventilation, and Air Condition system (HVAC) with two different working fluids refrigerant(R410a) and nano refrigerant (R410a+Al2O3). Design of experiment was employed, to fix the number of trials. Fresh air temperature, flow rate of air, filling ratio and volume of nano particles are considered as factors. The effectiveness is considered as response. The results were analyzed using Response Surface Methodology

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