Comprehensive Utilization System Research Articles

Analysis and Prospect of Waste Heat Utilization from Blast Furnace Slag Flushing

Estimating the residual heat of blast furnace slag flushing in China, classifying and introducing the current proposed methods of slag flushing waste heat utilization, and listing existing cases. In order to better save energy and water in the slag flushing process of blast furnaces, an ideal comprehensive cascade utilization system scheme for annual recovery of waste heat is proposed. Based on the measured waste heat data of a steel plant, design calculations are carried out to further analyze the economic feasibility of the new scheme and provide reference for its promotion and application.

Performance prediction of a novel solar power tower system based on spectral beam splitting

Photovoltaic technology is currently the most widely used solar generation technology in engineering. The particular spectral response band of PV cells cannot convert all solar radiation into electricity. Meanwhile, some radiation will become heat, leading to an increase in cell temperature and a decrease in the conversion efficiency of photovoltaic cells. Spectral splitting technology is an effective technology to improve electrical generation efficiency and can achieve full spectrum utilization of solar energy. The current work involved (1) proposing a novel solar power tower comprehensive utilization system based on spectral splitting; (2) developing a spectral splitting thin film configuration by using the Needle method whose transmittance is higher than 90% against the band range of 510 nm-1, 020 nm; (3) setting up a spectral splitting PV panel whose cover glass is coated the developed film, and replacing the heliostat of SPT system by using such spectral splitting PV panels; (4) predicting the electrical power generation of the spectral splitting-based tower type concentrating solar power system. The results demonstrate that the power generation efficiency of the proposed system is 5.5% and 3.46% higher than PV power generation and SPT systems respectively.

Evaluation of by-product-gas utilization options for carbon reduction at an integrated iron and steel mill

The comprehensive utilization of steel mill by-product gases is an important method for achieving climate goals. In this study, a comprehensive model is proposed for analyzing carbon-emission reduction strategies of by-product gases comprehensive utilization system at an integrated iron and steel mill. The model is used to explore carbon-emission reduction performance applying blast furnace with top-gas recycling (TGR-BF) and carbon capture and storage (CCS) applications, as well as consequent influence on steam and power cogeneration system (SPCS) operation. Carbon-emission intensity, total emission reduction and unit reduction cost are used to evaluate the carbon reduction result of by-product gases comprehensive utilization system. The results of the study indicate that the upgrade of SPCS can achieve an emission reduction of 311,200 tCO2, and the carbon-emission intensity of the power and heat supply can be reduced by 0.14 tCO2/104 kWh and 0.02 tCO2/GJ, respectively. After TGR-BF technology is applied, the total emission reduction peaks at the top-gas recovery rate of 6%, which is 85,100 tCO2. The unit reduction cost is also minimized at the top-gas recovery rate of 6%. Sensitivity analysis indicates that the reduction of power price significantly reduces the unit reduction cost.

Exergy, energy, economy analysis and multi-objective optimization of a comprehensive energy utilization system for LNG-powered ships based on zero-carbon emissions

To realize efficient utilization of energy in LNG-powered ships and zero-carbon emissions, a comprehensive energy utilization system based on zero-carbon emissions for LNG-powered ships is proposed in this study coupling the full utilization of LNG cold energy and flue gas waste heat with the carbon capture technology of oxygen-enriched combustion with the LNG dual-fuel-powered bulk carrier as the object as well. By system modeling, the system is analyzed using the thermoeconomic method and the operating parameters are studied. The results demonstrate the selection of the working fluid combinations and the settings of the operating parameters of equipment affect the system's thermodynamic and economic performance. Based on the parameters analysis, a multi-objective genetic algorithm is adopted for optimization. The optimization results indicate that 51.71 % exergy efficiency and 511 kW net output power are achieved under the zero-carbon emissions condition, while the initial investment cost and cost of power generation are 6.33·106$ and 0.0869$/kWh, which indicate the system is of excellent environmental and economic benefits.

Design and Analysis of Comprehensive Solar Utilization System Based on Photovoltaic Concentration and Spectral Splitting

In order to address the issue of a solar utilization system with low efficiency, this paper designs a new solar conversion system based on photovoltaic concentration and spectral splitting. The system concentrates sunlight through a Fresnel lens and uses a hollow concave cavity to evenly distribute the incident energy flow. The spectral splitting medium separates the useful irradiance for the PV cell from those wavelengths that are more suited to heat generation. By considering the available wavelength of photovoltaic cells, the GaAs cell and a ZnO nanofluid were selected for this paper. It was found that installing the hollow concave cavity improved the spot uniformity of the PV cell surface by 17%. The output efficiency of the system under various circumstances was analyzed. The results show that at a concentration ratio of 50 and a light intensity of 1000 W/m2, photoelectric conversion efficiency increased by 0.81%. When compared to direct concentration, the photoelectric conversion efficiency increased by at least 7%. Meanwhile, the comprehensive electrical efficiency was 36.7%, which is higher than that of the normal concentration PV and comprehensive thermal system.

Study on fuel cold energy utilization of large ammonia powered ship

Taking large ammonia powered container ship as the research object, a set of liquid ammonia cold energy cascade comprehensive utilization system is designed. The system mainly includes low temperature cargo hold system, high temperature cargo hold system and marine air conditioning system. Aspen HYSYS software is used to simulate the system scheme. Based on the utilization rate of cold energy in the low temperature cargo hold system, the maximum of liquid ammonia flow fraction under different operating conditions was determined, and the cold energy utilization system exergy efficiency was calculated. In the 75% working condition of the ship, when the flow fraction was 40%, the whole cold energy utilization system exergy efficiency was 34.42%, in this way, the effective utilization of liquid ammonia cold energy is realized.

Multi-energy coordination control method of power system connected to microgrid of combined cooling, heating and power

The problems of energy shortage and ecological destruction are becoming increasingly serious. As a comprehensive energy utilization system, cogeneration system has gradually become a research hotspot. In order to improve the basic frequency stability and reduce the operation cost, this paper presents a multi-energy coordinated control method for CHP micro-grid. Firstly, the topology of CCHP system is analyzed. On this basis, this paper constructs a CCHP power system including micro turbine (MT) and air conditioning (AC). Secondly, a multi-component composite energy storage method for power system is proposed. Different types of energy storage devices than a single way of energy storage has better performance, to achieve multi-complementary. Finally, in the construction of power system collaborative control model, this paper constructs power system collaborative control model based on load storage optimization idea of source network. Experimental results show that the proposed control method has strong fundamental frequency stability and low operating cost, and has certain application value.

Research status and prospects on overall mineral use of mixed-dimensional attapulgite clay

<p indent="0mm">In recent years, the high-efficiency and high-value development and use of mixed-dimensional clay minerals with large natural reserves have attracted great attention with the over-exploitation and rapid consumption of high-quality clay mineral resources. The reserves of mixed-dimensional attapulgite clay ore in China exceed 1 billion tons. Their main mineral component is attapulgite, but they also contain illite, chlorite, kaolinite, illite-smectite mixed-layer minerals, and other minerals. At the same time, the phenomenon of isomorphic substitution is common, and part of the octahedral sheet may be replaced by Al³⁺, Fe³⁺, and other metal ions; therefore, the mixed-dimensional attapulgite clays are mostly brick-red, gray, or khaki. The relative complexity of associated minerals and darker color restrict the large-scale development of the industry. Scientific and technological innovation to realize the “best use” of mixed-dimensional clay mineral resources to develop high-value-added products will be the most important development trend in the future. However, basic theoretical research on the high-value application of mixed-dimensional clay minerals is lacking, so new ideas, approaches, and methods are urgently needed to solve the difficulties and sore points of industrial development. On the basis of a deep understanding of the microstructure of clay minerals, progress has been made in using the total mineral resources of mixed-dimensional attapulgite clay, which has preliminarily formed a comprehensive utilization system of “simultaneous transformation of associated minerals—acid leaching for whitening—functional material construction—recovery of acid leaching metal ions—clay mineral biochar—create red pigments based on the red appearance—quartz sand utilization”. Specifically, using mixed-dimensional attapulgite clay to construct various porous silicate materials by structural reorganization; developing a series of methods, including wet, semi-dry, and microwave techniques, to achieve efficient whitening-variegated mixed-dimensional attapulgite clays without damaging the aspect ratio of attapulgite nanorods and the properties of other associated minerals; using the whitened mixed-dimensional attapulgite clays containing one-dimensional fibrous attapulgite and two-dimensional layered clay minerals to construct nanocomposites, such as films and plastics, showing the advantages of mixed-dimensional attapulgite clays in improving mechanical properties and realizing the high value of associated minerals; recovering iron, aluminum, magnesium, and other metal ions from the wastewater of acid leaching attapulgite clay to synthesize layered double hydroxide materials to adsorb dyes, antibiotics, and other organic matter, then producing mineral biochar materials by anaerobic calcination for heavy metal-contaminated soil remediation; using the iron-rich properties of mixed-dimensional attapulgite clays to construct nanohybrid iron-red mineral pigments, which significantly improve the weather resistance of iron-red pigments; and employing quartz sand obtained by dry separation from clay minerals to construct cobalt-blue hybrid pigments via mechanochemical method. The long-term practice has shown that whitening is the premise for the high-value use of mixed-dimensional attapulgite clays, and overall mineral use is the key to industrial development. Therefore, an effective way to simultaneously transform associated clay minerals into attapulgite or other single minerals should be further explored. The structural regulation and transformation mechanism of mixed-dimensional attapulgite clays should be clarified to open a new approach for the functional application of mixed-dimensional attapulgite clays. In addition, on the basis of the acid leaching for whitening, the differences and complementarities of one-dimensional rod crystals and two-dimensional layered structures in constructing functional composite materials must be systematically studied, and the foundation for mixed-dimensional nanorod crystal/layered structures in functional materials must be laid, finally providing a feasible and reliable approach for the comprehensive use of mixed-dimensional attapulgite clay resources.

Construction and Optimization of Liquefied Natural Gas Regasification Cold Energy Comprehensive Utilization System on Floating Storage Regasification Unit

Construction and Optimization of Liquefied Natural Gas Regasification Cold Energy Comprehensive Utilization System on Floating Storage Regasification Unit

A systematic construction of water-electricity cogeneration and thermal membrane coupling desalination technology using the waste heat in steel industry

The widespread use of fossil energy emits a large amount of carbon dioxide, leading to the greenhouse effect and global warming. The essence of reducing carbon emissions is to achieve higher-quality sustainable development. The recycling of waste heat in the iron and steel industry is of great significance to reducing carbon emissions. Aiming at the problem of insufficient utilization of gas in iron and steel industry and the development of seawater desalination industry, a water-electricity cogeneration and thermal membrane coupling technology is established. Low-temperature multi-effect distillation seawater desalination device is directly connected with steam turbine generator, which uses gas to generate electricity. After generating electricity, negative pressure exhaust at the end of steam turbine is used for seawater desalination. The thermal efficiency of the system is increased to over 80%, the waste heat is effectively utilized, and the carbon emission in the thermal desalination process is reduced. At the same time, the high-efficiency removal and resource utilization of salt in concentrated seawater are realized. The recovery ratio of freshwater is over 55%, the salt content of freshwater is below 500 mg/L, and the salt content of seawater concentrated by membrane method can reach 79,450 mg/L. A new comprehensive utilization and recycling system of seawater has been constructed to realize efficient recycling of energy resources and promote the development process of carbon emission reduction.

Thermodynamic analysis of a comprehensive energy utilization system for natural gas pressure reduction stations based on Allam cycle

• A comprehensive energy utilization system for natural gas pressure reduction stations based on Allam cycle is proposed. • The effects of key parameters on the proposed system performance are clarified. • The proposed system and the pre-heating system are compared and analyzed. • Energy efficiency is 99.31% with turbine inlet parameters of 30 MPa/900 °C. In order to effectively utilize the pressure energy and cold energy of the natural gas pressure reduction stations, this paper proposes a comprehensive energy utilization system for natural gas pressure reduction stations based on Allam cycle. The low-grade waste heat during the Allam cycle and ambient heat are used to heat the decompressed natural gas to the temperature required by the user. Based on the established mathematical model, the effects of turbine inlet temperature, turbine inlet pressure, turbine outlet pressure, isentropic efficiency of power equipment, and natural gas expansion stages on the performance of the proposed system are studied. The proposed system and the pre-heating system are compared and analyzed. The results show that when the combustor outlet temperature is 900℃, the energy efficiency and incremental efficiency of the proposed system are 99.31% and 103.55%, respectively. Compared with pre-heating system based on gas turbine cycle, they have increased by 9.84 percentage points and 19.32 percentage points, respectively. Compared with the boiler-based post-heating system, the energy efficiency is increased by 3.5 percentage points.

Thermodynamic performance analysis of comprehensive utilization system driven by geothermal energy

In order to improve the utilization rate of geothermal energy and realize the comprehensive utilization of geothermal energy. In this paper, a comprehensive utilization system using geothermal energy is proposed, and the thermodynamic performance under different working conditions is studied and analysed. And the Pareto method is used to optimize the calculation of different optimization options. The conclusions are as follows: The system can supply heating, cooling and electricity at the same time, and can regulate the electricity and cooling capacity according to the demand. The optimal pressure exists in the system in front of the turbine inlet to maximize the net output power of the system (when k=0). Due to heating needs, the adjustable range of k decreases with increasing of the turbine inlet pressure when the pressure of the turbine inlet is greater than 13.83 MPa. When there are differences in the importance of different output objectives, the Pareto solution is different. The importance degree of output objectives can be defined according to the demand, so as to solve the corresponding optimal solution.

Design of utilization cold energy and economic analysis on LNG carrier

Based on the principle of energy cascade utilization, this research uses 147000m3 LNG carrier as the research object. According to the principle of energy cascade utilization, LNG cold energy is applied to Rankine cycle power generation, ship desalination, ship low-temperature cold storage, ship high-temperature cold storage, ship air conditioning and nitrogen production, etc. Design a set of LNG cold energy comprehensive utilization system. Using Aspen HYSYS software for simulation, after analysis and calculation, the feasibility of the system design scheme was demonstrated. According to the route of the parent ship and the operating conditions of the cold energy utilization system, calculate the electricity and economic benefits saved by the LNG cold energy utilization system in each month. Through calculation, it can be known that 1.886×106 kW·h of electricity can be saved in one year, resulting in a benefit of more than 4 million yuan. The results show that the cold energy utilization system can bring good economic benefits and is worthy of promotion and application on ships.

Analysis and Optimization of Saline-alkaline Water Comprehensive Utilization System

On the basis of the previous field experiment and the actual situation in Xinjiang, four saline-alkaline water comprehensive utilization systems are proposed to optimize concentration and desalination process. Based on chemistry, thermodynamics and heat transfer, combined with economic costs and benefits, steam production and entransy are analyzed in this paper, the results show that the comprehensive efficiency of the dual heat source system is better than that of the single heat source system. Two-stage dual heat source system with series and parallel multi pass heat collecting has the best efficiency, but the comprehensive efficiency is similar to that of single-stage dual heat source system. These systems have their own strengths, which provide reference for brine treatment in salinization areas.

Design and optimization of LNG vaporization cold energy comprehensive utilization system based on a novel intermediate fluid vaporizer

In this paper, a novel type intermediate fluid vaporizer with LNG vaporization cold energy utilization was proposed and applied to 9200TEU container LNG power ship. Considering the different LNG vaporization parameters of the ship's main and auxiliary engines and the requirements of shipping for power generation, seawater desalination, cold storage and air conditioning, a comprehensive utilization system of LNG vaporization cold energy was constructed with a novel intermediate fluid vaporizer. Through the simulation and analysis of the scheme, and based on the cascade utilization of cold energy, the design scheme was optimized from the perspective of process arrangement and refrigerant selection. Finally, the parameter matching optimization of the determined optimization design scheme was carried out by using genetic algorithm. The results showed that the overall exergy efficiency of the optimal design scheme of the cold energy cascade utilization system of the ship LNG built in this paper based on the novel intermediate vaporizer was 51.09%, the net output electric power of the system was 342.228 kW, and the net profit of the system was about US $224,300 per year, and the cost was recovered in 7 years.

Design of Comprehensive Utilization System of Semiconductor Thermal Power Generation

For the solar steam generation system, optical materials are obtained through experimental comparison and verification. A nanofluid material composed of a double-layer structure with a light absorber on the upper layer and an insulating material with two-dimensional or three-dimensional water transport channels on the lower layer is proposed, which is hydrophilic It uses capillary force and promotes fluid flow to the hot zone, and interconnected pores are used for fluid flow in and out of the structure. The device is embedded with a semiconductor thermoelectric power generation sheet in the lower layer, the upper surface is in contact with the photothermal layer, and the lower surface is in contact with bulk water. The temperature difference is formed and the electromotive force is generated, which makes the energy utilization efficiency higher.

Multi-Criteria Evaluation of Distributed Energy System Based on Order Relation-Anti-Entropy Weight Method

Distributed Energy System (DES), a comprehensive energy utilization system distributed on user side, has been recognized as a promising energy utilization method that can improve energy efficiency, reduce greenhouse gas emissions, and achieve sustainable development. However, the DES is usually driven by various energy sources, and it is a complex issue to decide the composition of the system. To improve the incompleteness of a single subjective or objective assessment. So, it is urgent to find a comprehensive and efficient decision-making method for different systems. This paper states a total of 23 indicators in 4 criterion group: technology, economy, environment, and society. Based on the combination of the order relation analysis method (G1) and the anti-entropy weighting method (a-EWM), a comprehensive evaluation model, order relation-anti-entropy weight model (G1-aEWM), of distributed energy is established. This comprehensive evaluation model is used to analyze a hospital in Henan and find the final solution for the distributed energy system of the hospital. The empirical analysis results verify the rationality of the comprehensive evaluation model and provide an evaluation basis for the establishment of distributed energy systems in the future.

Organic Compound Degradation Induced by Br Oxidation with O3 Fine Bubble Injection into Seawater

ABSTRACT An advanced technique for the utilization of the dissolved Br in concentrated seawaters discharged from the salt manufacturers in Japan can enable the development of a comprehensive utilization system for seawater resources. Hypobromous acid (HOBr) and hypobromite ion (BrO–) obtained by the oxidative reaction of Br– degrade the many organic compounds and can be utilized as water purification reagents with excellent decolorizing and disinfection capabilities. In this study, we focused on the production of Br oxyacid as an upgrading method for Br using O3 fine bubbles, which has a high oxidation potential, and developed a technique for water purification. When O3 fine bubbles are introduced into the liquid phase, the gas absorption of O3 is accelerated by the increases in gas–liquid interfacial area and residence time of the bubbles and the hydroxyl radical (OH•) generation is enhanced by the increase in contact probability between the dissolved O3 and accumulated OH– at the minute gas–liquid interfaces. Moreover, when O3 fine bubbles are supplied into a liquid phase with coexisting Cl– or Br– as halogen ions, further improvement in oxidation potential in the liquid phase can be expected by the acceleration of the Br oxyacid generation with OH•. When O3 fine bubbles with an average diameter of 50 µm were continuously supplied into the simulated seawater with pH value of 6.1 or ion-exchanged water with pH value of 5.6 at a constant solution temperature (T S) of 298 K, the concentration of active oxygen species (C OS) in the simulated seawater increased to 1.4 times higher than that in the ion-exchanged water. Additionally, in the case where O3 fine bubbles were injected into an aqueous solution of NaCl, MgCl2, CaCl2, KCl, or NaBr to ascertain the factor of C OS increment, the tendency of C OS to increase with the reaction time in the NaBr aqueous solution was more apparent than those in the ion-exchanged water and other salt aqueous solutions, because oxyacids of Br such as HOBr/BrO– were generated by the selective oxidation of Br– during the O3 fine bubble injection into the NaBr aqueous solution. Furthermore, to evaluate the effects of the Br– concentration on the degradation of methylene blue (MB) as an organic compound, MB was degraded by O3 fine bubble injection into NaBr/MB aqueous solutions with different initial NaBr concentrations. The formation of Br oxyacids owing to the acceleration of the reaction between O3 or OH• and Br− during the O3 fine bubble injection led to an enhancement in MB degradation.

Comprehensive utilization system of waste heat of hydrogen fuel cell powered ship

At present, about 50% of the energy of hydrogen fuel cells is converted into heat energy loss, and the comprehensive energy utilization technology is still immature. For the transport ship powered by proton exchange membrane hydrogen fuel cell, a set of comprehensive waste heat utilization system was designed through theoretical calculation and simulation analysis. A set of self-adaptive controllers with PLC (Programmable Logic Controller) as the core and fuzzy PID (Process Identification) control law based on the collected operating parameters and environmental parameters of each module was developed to control the input energy of each module. Based on the fuel cell-powered green ship technology, this system realizes the cogeneration of low-grade heat sources of hydrogen fuel cells, which greatly improves energy utilization efficiency. The results can promote the application of fuel cells in ships.

Design of LNG gasification and thermal energy comprehensive utilization system for vehicles

The development of new energy vehicles is one of the important measures for national energy conservation and emission reduction, and natural gas is an important part of new energy. At present, most natural gas vehicles on the market are CNG vehicles, and LNG has many advantages, mainly solving the problem of vehicle life. This work has designed a vehicle LNG gasification system, including the design of stable self-pressurization and new gasifier, so that LNG can be used instead of CNG in the car, and it can be combined with the designed thermal energy comprehensive utilization system, which can utilize LNG. Cold energy can further reduce energy consumption and achieve energy saving and emission reduction. We first carried out the theoretical check calculation, then completed the piping design of the system, and carried out the ANSYS simulation analysis of the key component gasifier, and verified the simulation results through experiments, and further simulated the system. Analyze, design and optimize the control mode of the system. On this basis, the system control is programmed based on the single-chip microcomputer. We also made the system model. It uses the single-chip microcomputer to control and can switch and display various working modes.