Environmental Protection Performance Research Articles

Control strategy for a CO2-based combined cooling and power generation system based on heat source and cold sink fluctuations

The CO2-based combined cooling and power system (CCP) is considered a promising solution for waste heat recovery due to its environmental protection and excellent performance. When it comes to refrigerated trucks' application, there are still critical challenges arising from the transient fluctuations of cold and heat sources. According to the poor correlation between the power sub-cycle and the refrigeration sub-cycle of the CCP system, this paper proposes various controls such as constant control and optimal control to control each cycle separately and achieve stable and optimized operation. The results show that the optimal pump speed and the split valve to limit exhaust control is an effective strategy for engine heat source fluctuations. Under the engine heat source slow step condition, the net work under this control is improved by 5%, and under the engine heat source transient condition, the net work under this control is only improved by 1.37%. In the case of cold sink fluctuations, the strategy of controlling the condensing pressure can reduce the maximum fluctuation of the cooling capacity from 5% under open-loop conditions to 2.5% under control. The above control methods can make the operation of the CCP system more stable and effective.

Air pollution and innovation performance of Chinese cities: human capital and labour cost perspective.

Environmental protection and innovation performance are key issues that affect the sustainable development and value growth of cities. Using data of 272 prefecture-level cities during 2002-2016 and 2,169 listed companies, and the air ventilation coefficient and government environmental regulations, as the instrumental variables for PM2.5 concentrations, this paper applies two-stage OLS (2SLS) to investigate how air pollution affects China's technological innovation and its realization mechanism. The results indicate that the rise in air pollution significantly inhibits the technological innovation level of regions as a whole as well as individual enterprises. When considering the spatial effect of the spread of PM2.5 concentrations, due to positive spillover effects on innovation activities, the spread of air pollution has negative impacts on technological innovation activities in surrounding cities. Human capital and labour costs are important channels through which air pollution influences China's technological innovation. The implementation of pilot carbon trading policies can effectively reduce air pollution and then contribute to the achievement of the goals of the green growth strategy.

Study on the thickening behavior and mechanism of supercritical CO2 by modified polysiloxane

Supercritical CO2 has been widely concerned because of its clean environmental protection and excellent performance. However, the low viscosity limits its wide application. To this issue, researchers usually use thickeners to improve its viscosity. The siloxane-type polymer is regarded as clean and cheap thickener. In this work, we screened potential supercritical CO2 thickeners by comparing the thickening properties of vinyl polysiloxane, hydroxyl polysiloxane and polydimethylsiloxane. The results show that vinyl polysiloxane has the best thickening performance. The dissolution and thickening behavior of vinyl polysiloxane are further studied. The results indicate that the dissolution pressure and thickening capacity of vinyl polysiloxane in supercritical CO2 increase with the increase of kinematic viscosity and concentration. At the experimental conditions, the maximum viscosity of supercritical CO2 can be increased to 14.87 mPa·s. In addition, the dissolution pressure of vinyl polysiloxane in supercritical CO2 decreases with the increase of cosolvent concentration, while the viscosity slightly decreases. Finally, the thickening mechanism of these thickeners was studied by molecular dynamics simulation. Based on the molecular simulation results, the roles of functional groups of thickeners in the dissolution and thickening process are discussed. It can provide theoretical support for the synthesis and screening of CO2 thickeners in the future.

Establishment of Performance Evaluation Model of Highway Environmental Protection Based on Deep Learning

As the foundation of the social economic system, public transportation roads play an important role in the development of the national economy. At the same time, the opposition between public transportation roads and the natural environment, ecological environment, and natural resources is becoming more and more obvious. This paper is aimed at studying the performance evaluation model of highway environmental protection based on deep learning. For this reason, related methods such as environmental protection, performance evaluation, and deep learning algorithms are proposed in the article, and corresponding experiments are also carried out in the article. The experimental results show that the highway environmental protection performance evaluation model based on deep learning can quickly help environmental supervisors to inspect the work of relevant highway environmental protection agencies and also accurately mention the environmental protection performance detection to 80%.

Design and Optimization of Combined Cooling, Heating, and Power Microgrid with Energy Storage Station Service

This study aims to symmetrically improve the economy and environmental protection of combined cooling, heating and power microgrid. Hence, the characteristics of configuration ways of energy storage devices in traditional combined cooling, heating and power systems are analyzed, and a scheme for the operator to establish an energy storage station is designed. An improved aquila optimizer for the optimal configuration of the system is proposed to symmetrically enhance the economic and environmental protection performance. The feasibility of the proposed scheme is verified through experiments in three different places. The results show that the economic cost and exhaust emission of the system with energy storage station are reduced to varying degrees compared with the system with energy storage equipment alone and the system without energy storage equipment based on symmetry concept. Especially in Place 1, the scheme with energy storage station in the system can reduce the electric energy purchased from power grid by 43.29% and 61.09%, respectively, compared with other schemes. This study is conducive to promoting the development of clean energy, alleviating the energy crisis, reducing the power supply pressure of power grid, and improving the profits of operators by symmetrically considering the economic and environmental performance of the system.

Development and performance evaluation of a novel environmentally friendly adsorbent for waste water-based drilling fluids

Abstract Adsorbent is an important waste water-based drilling fluid treatment agent, which can adsorb and settle heavy metal ions, high polymer organics, and other soluble harmful substances in the waste drilling fluid. Traditional adsorbents such as polyaluminum chloride and polyacrylamide will produce other metal ions or toxic monomers after hydrolysis, which cannot fully meet the requirements of safety and environmental protection. Therefore, a new environmentally friendly waste water-based drilling fluid adsorbent, named RH-β-CD, was prepared by the Wilson etherification reaction, which was initiated by epichlorohydrin and ceric ammonium nitrate, and successfully grafted rhamnolipid and amine strong adsorption groups onto β-cyclodextrin. The adsorption effect and environmental protection performance of RH-β-CD on the organic matter and chromium ion in waste sulfonated water-based drilling fluid were evaluated and compared with commonly used adsorbents such as activated carbon, PAM, and polyaluminum chloride. The results show that RH-β-CD can effectively adsorb the organic matter in the filtrate of waste water-based drilling fluids, reduce its chemical oxygen consumption, and reduce the concentration of heavy metal ions in the filtrate. The effect is better than PAM, activated carbon, and polyaluminum chloride, with the BOD5/CODcr >20% and EC50 >1,000,000 mg·L−1, which is environmentally friendly.

Does environmental pollution weaken the positive effect of government public expenditure on residents’ subjective well-being? A case study in China

With the deepening of government reform, the Chinese government has strengthened the functions of public service and social management. Public policies are increasingly concerned with residents’ well-being. However, environmental quality, which can be regarded as a visual indicator to reflect the performance of environmental protection and the quality of public service, is still not optimistic in China. Thus, we wonder if there exist deep relationships among public expenditure, environmental pollution, and subjective well-being. By combining the data from the Chinese Family Panel Survey (CFPS) with relevant government statistics, we find that public expenditure improves residents’ well-being, whereas environmental pollution has a negative effect. More importantly, environmental pollution is found to moderate the relationship between government expenditure and residents’ subjective well-being. These findings not only prove the extra costs of environmental degradation, but also suggest that good performance of environmental governance should be emphasized in promoting human welfare.

Investigation of effects of reactive MgO on autogenous and drying shrinkage of near-neutral salt activated slag cement

Near-neutral salt activated slag cement has better performance in environmental protection and shrinkage behavior than common sodium silicate -activated slag (AAS) cement. However, the growth of mechanical performance is too slow, which limits its application. Reactive MgO can improve early mechanical properties, while it may have different effects on the shrinkage due to changes in alkali-activators. Two near-neutral salts, sodium carbonate (SC) and sodium sulfate (SS), were selected to prepare AAS cement. The influence of reactive MgO on autogenous and drying shrinkages was studied. The hydration process and pore structure were assessed with hydration heat and nitrogen adsorption, respectively. The phase composition was evaluated by thermogravimetry (TG/DTG) and X-ray diffraction (XRD). The results indicate that the addition of reactive MgO increases the autogenous shrinkage of SC and SS activated slag. This is mainly due to accelerated reaction by reactive MgO. The drying shrinkage of AAS mortars activated with SC increases first and then decreases with the increase in reactive MgO. For SS activated slag, the more the reactive MgO used, the lower the drying shrinkage is observed. This is related to the effect of reactive MgO on pore structure and hydration products. When reactive MgO increases from 2% to 10%, the mesopore in SC activated slag increases at first and then decreases, while the SS activated slag group shows a constant decrease. Reactive MgO promotes the formation of hydrotalcite in SC activated slag, while AFt is found in SS activated slag. Hydrotalcite and AFt are crystalline products, which are beneficial to inhibit drying shrinkage.

Investigation of Dynamic Characteristics of Liquid Nitrogen Droplet Impact on Solid Surface

Liquid nitrogen spray cooling technology exhibits excellent heat transfer efficiency and environmental protection performance. The promotion of this technology plays an important role in improving the sustainable development of the refrigeration industry. In order to clarify its complex microscale behavior, the coupled Level Set-VOF method was adopted to study the dynamic characteristics of liquid nitrogen droplet impact on solid surface in this paper. The spreading behaviors under various factors (initial velocity, initial diameter, wall temperature, and We number) were systematically analyzed. The results show that the spreading behaviors of liquid nitrogen droplet share the same process with the normal medium, which are rebound, retraction, and splashing. For the droplet with smaller velocity and diameter, Rebound is the common phenomenon due to the smaller kinetic energy. With the increase of droplet diameter (0.2 mm to 0.5 mm) and velocity (0.1 m/s to 5 m/s), the spreading factor increases rapidly and the spreading behaviors evolve into retraction and splashing. The increase of wall temperature accelerates the droplets spreading, and the spreading factor increases accordingly. For the liquid nitrogen droplets hit the wall, the dynamic behaviors of rebound (We < 0.2), retraction (0.2 < We < 4.9), and splashing (We > 4.9) will occur with the droplet weber number increased, which are consistent with the common medium. However, due to liquid nitrogen having lower viscosity and surface tension, the conditions of morphological transformations are different from the common media. The maximum spreading diameter has a power correlation with We, the power index of We is 0.306 for liquid nitrogen, lager than common medium (0.25). The reasons are: (1) the better wettability of liquid nitrogen, and (2) the vapor generated by the violent phase change ejects along the axial direction. The article will provide a certain theoretical basis for liquid nitrogen spray cooling technology, and can also enrich the flow dynamics of cryogenic fluids.

Process Safety and Environmental Protection Performance, Environmental and Economic Evaluation of Natural Ventilation System: Experimental Analysis

Process Safety and Environmental Protection Performance, Environmental and Economic Evaluation of Natural Ventilation System: Experimental Analysis

Effect of Curing Agent Dosage on Fire Resistance of Waterborne Epoxy Coating

The water-based epoxy fire retardant coating is formed by reaction curing, which not only has good anti-corrosion performance, but also has environmental protection and flame retardant performance, which is suitable for construction machinery painting or steel structure buildings. However, the curing and cross-linking process of water-based epoxy coatings is centered on the curing agent, which gradually diffuses into the epoxy resin particles. The curing agent molecules first contact the surface of the epoxy resin dispersed phase particles and undergo a cross-linking curing reaction. As the reaction progresses, the relative molecular weight and glass transition temperature of the epoxy resin on the particle surface gradually increase, so that the diffusion rate of the curing agent molecules into the particles gradually slows down, which means that the curing reaction inside the epoxy resin dispersed phase particles Less than its surface, resulting in a low internal crosslink density, and ultimately not all epoxy groups have the opportunity to interact with the activating groups of the curing agent. Therefore, this paper studies different proportions of waterborne epoxy emulsion and curing agent. The results show that when m (epoxy emulsion): m (curing agent) = 7:3, the fire resistance and comprehensive performance of the coating are the best.

Treatment of Waterborne Coating Wastewater by Coagulation Sedimentation Fenton Oxidation Process

waterborne coatings have become the development trend of the coating industry because of their less use of organic solvents and good environmental protection performance. However, the wastewater produced in the production process of waterborne coatings has become a difficult pollution source. Based on this, this paper uses coagulation sedimentation method and Fenton oxidation method to treat waterborne coating wastewater. Taking the COD of treated wastewater as the research index, this paper studies various factors affecting the treatment effect of coagulation sedimentation and Fenton oxidation. Through single factor analysis, the results show that the best dosage of PFS and PAM is PFS: 8 g/L and PAM: 0.8 g/L; In Fenton oxidation, the dosage of H2O2 is 9.98mL/L, the dosage of FeSO4 · 7H2O is n (Fe2+): n (H2O2) = 1:6, pH is 2, and the dosage times are 2.

Life Cycle Assessment of Biochar Preparation of Chinese Traditional Medicine Residue by Low-temperature Pyrolysis

This study aimed to evaluate the environmental impacts of the biochar production process through low-temperature pyrolysis of Chinese medicine residue via life cycle assessment (LCA). An LCA model consisting of biomass pretreatment, pyrolysis, separation and cooling was developed. The results indicated that the low-temperature pyrolysis process has the highest environmental impact on AP and GWP. The consumption and direct emission of pyrolysis process were the primary sources of environmental impact. In addition, by comparing to the traditional landfill process of Chinese medicine residue, it turns out that the low-temperature pyrolysis process has improved environmental protection performance.

Aging test and performance prediction of rubber in mortar medium

Rubber has superior performance and is widely used, but it is easy to age under the influence of the environment, which leads to the decline of its performance. Rubberized concrete is a new type of building material, which attracts attention because of its environmental protection and good dynamic performance. Based on the environment of rubber in rubberized concrete, the accelerated aging test of rubber in mortar medium is designed in this paper. Through the rubber hardness test and cyclic loading test, the change rule of rubber hardness and loss factor with aging was analyzed. The hardness and loss factor of rubber at 25 °C were predicted by fitting the aging kinetic equation. The results show that the aging of rubber in mortar medium leads to the change of performance of rubber. More specifically, the conclusion is as follows: 1. The hardness and loss factor of rubber show the opposite change rule during rubber aging. With the increase of aging temperature and time, the hardness of rubber increases. After 28 days of aging, the hardness of the rubber increased by 6.9% (80 °C) and 16.4% (100 °C) respectively, its loss factor decreased to 77.2% (80 °C) and 71.6% (100 °C) of the initial value, respectively. 2. Using the results of the accelerated aging test, it is concluded that the Shore hardness of the rubber in mortar medium will no longer increase after 40 years of aging, and the loss factor decreases to 61.4% of that before aging. This paper presents a reference for the application of rubber in mortar medium, and also provides support for further research into rubberized concrete.

Path Optimization Model for Urban Transportation Networks under the Perspective of Environmental Pollution Protection

In view of the lack of consideration of environmental protection performance in the traditional path optimization model, a path optimization model for urban traffic networks from the perspective of environmental pollution protection is proposed. Firstly, the urban real-time traffic condition is expressed by the road traffic state index, and an integer programming model is established to optimize the route with the goal of low carbon and shortest distribution time. Then, a hybrid particle swarm optimization algorithm combined with adaptive disturbance mechanism based on variable neighborhood descent is designed, which can better carry out adaptive disturbance according to the situation that the population falls into local extreme value, and the 2-opt local search method is introduced to improve the quality of solution. Finally, the improved particle swarm optimization algorithm is used to solve the two-objective model to obtain the Pareto front solution set, that is, the path scheme under real-time traffic conditions. The experimental demonstration of the proposed model based on two application scenarios shows that its distribution cost, distribution time, and carbon emission are 1975 yuan, 27 h, and 213 kg, respectively, which are better than other comparison models and have high application value.

Study on the performance of K0.3Ti4O7.3(OH)1.7 fiber in Li+ recovery

This study aims to explore the potential use of fibrous K0.3Ti4O7(OH)1.7 (KTO(OH)) as adsorbent in the enrichment and segregation of Zabuye Salt Lake containing Li+. X-ray diffraction scanning (XRD), Brunauer–Emmett–Teller (BET), Fourier transform infra-red (FTIR) and scanning electron microscopy (SEM) were used to study the phase and morphological properties of KTO(OH). The results showed KTO(OH) was stable in space and had many adsorption sites, with 47.34-m2/g BET surface area. Adsorption capacity is 27.63 mg/g. In addition, pseudo-second-order kinetic model was fitted to verify its adsorption process. After repeating five times, the circulating adsorption capacity can still reach 91.67% of the initial adsorption capacity. The mass loss ratio of KTO(OH) was 0.85% and KTO(OH) shows excellent performance of environmental protection and pollution-free.

Hemp straw carbon and Ni/NiO embedded structure composites as anode materials for lithium ion batteries

Biomass derived carbon and its composites are widely used in lithium-ion batteries because of their simple process operation, environmental protection, low price and excellent performance. In this work, the composite of Ni/NiO nano spherical particles and hemp straw derived carbon showed a reversible lithium storage capacity of 1200 mA h g−1 after 650 cycles at a current density of 2 C (1 C = 718 mA g−1). Through transmission electron microscope and scanning electron microscope analysis, the results showed that Ni/NiO nano spherical particles were embedded on the surface of hemp straw carbon block. The excellent properties of the composite are attributed to the fact that biomass carbon can improve the overall conductivity and alleviate the structural strain caused by the change of Ni/NiO volume during charge and discharge. This work provides a new choice for biomass derived carbon loaded transition metals to prepare anode materials for lithium ion batteries.

P‐12.11: Researching on Wide Color Gamut of TV Products

Liquid crystal display technology is widely used because of its advantages of light weight, environmental protection and high performance. Compared with the emerging organic light‐emitting display, the color performance of liquid crystal display needs to be further improved. Increasing color saturation, displaying bright pictures and pursuing more realistic picture quality is a trend of the development of liquid crystal display technology.

Design of portable recyclable drainboard set-up

For the traditional drainboard set-up device obvious disadvantages: the structure is bulky, loading complex, often need drainage plate body, affecting the drainage effect, almost impossible to recycle, poor environmental protection performance, due to the effect of deformation, late work and other devices have interference, the drainage itself difficult to regulate in the process of setting up. In order to achieve the light, automatic, non-destructive and recyclable of drainage plate, improve the obvious shortcomings mentioned above, a series of improvements are made to the drainage plate set-up device. Through the verification of laboratory experiments, the problems such as large, bulky, high vulnerability and low recovery rate are solved, and the laboratory simulation has no suitable equipment, which reduces the space occupancy rate, saves resources and so on, and greatly reduces the cost of experiments. In water engineering applications, this new type of drainboard discount ingress than the existing drainboard plug-in machine, can be a good substitute for improving the status quo of the project.

Can the performance evaluation change from central government suppress illegal land use in local governments? A new interpretation of Chinese decentralisation

Chinese decentralisation, characterised by the fiscal decentralisation and political centralisation relationship between the central government and local governments, has provided significant dual incentives (financial incentives and political incentives) on the land use behaviour of local governments. However, traditional incentive theory ignores the impact of the constraint indicators set by the central government in performance evaluations. Considering the changes in China’s political performance evaluation system, and in particular, the strengthening of environmental protection and cultivated land protection, this study constructs a theoretical framework for the financial incentives, political incentives, and political constraints and provides a new perspective to explain the political restraint mechanisms for the governance of illegal land issues. Based on panel data from 30 provincial regions from 2000 to 2016, we applied the fixed-effect model and FGLS method and further tested the potential endogeneity problem. The results demonstrated: (1) Fiscal decentralisation has intensified local fiscal pressures, resulting in local governments wanting to obtain more land transfer and tax revenue, which has created a fiscal stimulus for the illegal use of land by local governments; (2) under political centralisation, the economic performance evaluation index has a strong promotion incentive effect, and is an essential driving factor for local government land violations; (3) the performance evaluation system that pays more attention to environmental protection and farmland protection has a restraint effect on illegal land use; and (4) at different stages of economic development, illegal land incentive sources and constraints differ. In terms of incentives, economically developed areas are primarily driven by tax revenue and political incentives, and land granting revenue incentives are not noticeable. Conversely, the less developed areas are primarily driven by financial incentives, while the political incentives are not apparent. For constraints, developed areas are more restrained by environmental protection performance, while underdeveloped areas are primarily constrained by cultivated land protection performance. We therefore argue that a dual relationship based on powerful incentive of “encouraging local to do” and strong restraint of “keeping the bottom line” is helpful to regulate and improve the behaviour of local governments.