Level Of Energy Savings Research Articles

Discussion on Building Environment and Energy Saving of HVAC

Against the backdrop of rapid socio-economic and scientific and technological development, HVAC has become an indispensable part of people’s daily lives in China. However, there are serious energy consumption issues in the use of HVAC, which not only bring significant economic costs but also exacerbate the pressure on energy supply, which is not conducive to the stable development of China’s social economy. The development of the construction industry needs to adapt to the needs of modern living environments, and the resource and energy consumption issues in the construction process are becoming increasingly prominent, profoundly affecting the sustainable development of society. In the social environment advocating green and environmental protection, people are pursuing a higher level of building environment. In building construction, energy-saving materials and equipment should be used more to contribute to the green mountains and waters. In order to improve the energy-saving level of HVAC, this article analyzes the impact of building environment on HVAC energy-saving and proposes some specific measures, hoping to provide effective reference for the development of HVAC energy-saving technology.

Multi-Objective Optimization of Daylight Performance and Thermal Comfort of Enclosed-Courtyard Rural Residence in a Cold Climate Zone, China

This study explored the daylight performance, thermal comfort, and energy-saving level of enclosed-courtyard rural residences with covered roofs in a cold IIA region of China. Using daylight autonomy (DA), annual mean value of PMV (AUMPMV), and total energy consumption of heating, cooling and lighting (Ehcl) in a performance evaluation index, a courtyard roof was optimized in a multi-objective fashion and analyzed for its effect on residential performance. This was achieved through field investigation and mapping, setting the prototype building model in the Rhino platform, and carrying out the iterative optimization design of the roof with a Ladybug tool component. The results show that appropriate roof form can significantly improve daylight performance, thermal comfort, and energy savings. Compared to the open-courtyard rural residence prototype model, the spatial daylight autonomy (sDA) of a flat-skylight-enclosed-courtyard residence decreased by only 0.94%, and AUMPMV improved significantly from −0.774 to 0.87. The Ehcl decreased by 19.7%, and compared with setting a large area of flat skylights on the roof, a reasonable clerestory window roof can achieve better residence performance.

Subsidy or not? How much government subsidy can improve performance level of energy-saving service company?

Contract energy management model is a new energy-saving mode based on single market mechanism. Due to its externality, the energy efficiency market cannot realize the optimal allocation of resources. Government energy-saving subsidy can solve the market failure of energy-saving service market and improve the performance level of energy-saving service company. However, due to the unbalanced support fields and single incentive tools in the government incentive policy, the incentive effect of the government subsidy policies for contract energy management projects is not satisfactory. Based on a two-stage dynamic decision-making model, this article analyzes the impact of different forms of government subsidy policies on the performance-level decision-making of energy service company, and draws the following conclusions: (1) The effect of the government's variable subsidy policy with payment conditions is better than the fixed subsidy policy without payment conditions. (2) Government incentive policy for contract energy management needs to be directed against different energy-saving fields. (3) The government should adopt different forms of incentive policies for energy-saving service companies with different energy-saving levels in the same energy-saving field. (4) When the government implements the variable subsidy policy with preset energy-saving target, each within a reasonable range, with the increase of which, the incentive effect on energy-saving service companies with lower energy-saving level decreases. When the subsidy policy has no incentive effect, it is more unfavorable for the energy-saving service companies which are below the average level of the industry.

Vehicle product-line strategy under dual-credit and subsidy back-slope policies for conventional/new energy vehicles

This study considers a monopoly automaker under dual-credit and subsidy back-slope policies to explore the automaker’s optimal product-line strategies and the impacts of the two policies on the economy and environment. By constructing a stylized pricing model that takes heterogeneous consumption preferences into account, we investigate how two policy programs, i.e., considering both dual-credit policy and subsidy back-slope policy (DS program) and only dual-credit policy (D program), affect the automaker’s product-line strategies, and determine the optimal vehicle pricing, energy-saving level and carbon emissions. The automaker has three product-lines strategies, i.e., conventional vehicle line (CV, C-plan), new energy vehicle line (NEV, N-plan), and CV-NEV line (M-plan). Then, sensitivity analyses are given to examine the impacts of exogenous variables (NEV credit price, subsidy back-slope) and endogenous variables (NEV technology capacity) on the automaker’s strategies. The results show that the automaker’s NEV technology capacity plays a vital role in the development of the environmentally friendly auto industry. Only when the technology capability reaches a certain threshold, the automaker is willing to take the initiative to produce NEVs. Subsidy back-slope can cause the sales countercurrent of NEVs, which can be alleviated by the NEV credit pricing mechanism.

Manufacturer-retailer coordination in a closed-loop supply chain system with emission reduction, government incentives, and energy-saving level

Manufacturer-retailer coordination in a closed-loop supply chain system with emission reduction, government incentives, and energy-saving level

Multi-Objective Optimization Design of Key Parameters of a Stepless Flow Control System with Multi-System Coupling Characteristics

The stepless flow control system offers important energy-saving technology for reciprocating compressors in the petrochemical and oil refining industries. Optimizing the movement characteristics of the unloader and suction valve is vital to improving the energy-saving level of the system and reducing the overall operating cost. However, the system has many of the characteristics of multi-system coupling and multi-parameter crossover; thus, it is difficult to optimize the key control parameters. In this study, to optimize the system inlet pressure, return pressure, and return spring stiffness parameters, a working model of the flow control system based on multi-system coupling was established. Using the ejection and withdrawal speeds of the unloader, the flow displacement deviation, and the gas work deviation of the control system as the optimization parameters, we used the response surface method to establish an optimization proxy model between the objective function and key parameters. Additionally, verification of the model’s accuracy and sensitivity analyses were completed. Finally, a double optimization scheme based on a non-dominated genetic algorithm (NSGA-II) was proposed. Simulation and experimental results show that with optimization of the return spring, oil inlet pressure, and oil return pressure, the unloader’s kinematic characteristics were also optimized at full load. The impact energy of the ejector and withdrawal speed of the unloader were reduced, and the compressor flow control error was less than 5%, which effectively improved the comprehensive working performance of the stepless flow control system.

Energy-saving optimization control method of commercial building double cold source air-conditioning units

In order to improve the energy-saving level of commercial buildings? air-conditioning units with double cold sources and reduce the energy cost, an energy-saving optimal control method of commercial buildings? air-conditioning units with double cold sources based on self-organizing neural network is proposed. Constrained parameter model of energy-saving control of commercial buildings? double-cold-source air-conditioning units is constructed. Taking the balanced real-time dynamic adjustment characteristic quantity of inverter of commercial buildings? double-cold-source air-conditioning units as the control object, combined with the fuzzy constraint method of variable frequency speed adjustment parameters and stroke adjustment power of commercial buildings? double-cold-source air-conditioning units, the steady-state adjustment of energy-saving output of commercial buildings? double-cold-source air-conditioning units is realized, and the self-organizing neural network control model of periodic potential energy load of building HVAC system is established. Combined with the small disturbance suppression method of motor rated power, the optimal control design of energy-saving of commercial buildings. The simulation results show that the output stability of the energy-saving control of commercial building air-conditioning units with double cold sources is good, the steady-state working ability is strong, and the energy-saving effect of commercial building air-conditioning units with double cold sources is good.

Evaluation Algorithm of Ecological Energy-Saving Effect of Green Buildings Based on Gray Correlation Degree

The environmental protection attribute and energy-saving level of green buildings cannot be described by the traditional evaluation model. In order to solve the above problems, a new ecological energy-saving effect evaluation algorithm of green buildings based on gray correlation degree is designed. Based on the framework of building energy-saving index system, the environmental protection evaluation standards are divided and the results are used to screen the energy-saving indexes, so as to complete the establishment of green building ecological energy-saving index system and standards. Then, the evaluation set is established, and the evaluation scale of each layer of indicators is accurately located according to the weight value of each index. On this basis, the membership matrix is constructed. By calculating the index weight and determining the fuzzy synthesis operator, the rating process of the algorithm is improved and the analysis of the evaluation algorithm of environmental protection and energy conservation indicators of green building materials based on gray correlation degree is realized. The experimental results show that the designed algorithm has good stability of the fitting curve, can save energy, and has low cost.

Impact of government subsidies on green supply chain operation under different power structures

Government subsidies play an important role in the operations of a green supply chain. However, the effectiveness of these subsidies under different power structures has rarely been examined. In this paper, we investigate a two-echelon green supply chain with a manufacturer who obtains government subsidies to develop and produce green products and a retailer who sells to consumers. We examine the impact of government subsidies on green product innovation, supply chain profits, and social welfare by focusing on five power structure models: centralized decision (C), manufacturer-Stackelberg (MS), retailer-Stackelberg (RS), vertical Nash (NL), and vertical Nash with bargaining mechanism (NB) models. The results show that government subsidies have a positive impact on the energy-saving level of green products, firms’ financial performance, and supply chain profits. We also find that the NB model is the optimal power structure of decentralized decision scenarios in terms of green product innovation, supply chain profits, and social welfare. Our findings indicate that if supply chain members have equal power and bargaining mechanisms the effectiveness of government subsidies will be enhanced. This study provides new theoretical insights for green supply chain research by revealing the interplay between the power structure of the green supply chain and government subsidies.

The Impact of Consumer Subsidy on Green Technology Innovations for Vehicles and Environmental Impact.

In the pressure of excessive resource consumption and serious environmental pollution, governments provide various consumer subsidies to promote sales of energy-saving vehicles, including the energy-saving fuel vehicle (FV) and the pure electric vehicle (EV) in the automobile industry. Utilizing a Hotelling model, this paper explores two competing firms’ decisions on the selection of green technology innovations for vehicles, namely producing either the energy-saving FV or the pure EV, while the two vehicles are different from each other on not only the energy-saving level but also the consumer’s acceptance. We further explore the impact of the government’s consumer subsidy on the profits, environment, and consumer surplus. We find that the two competing firms’ equilibrium selections of green technology innovations for vehicles change as the variable manufacturing cost of the pure EV varies. In particular, when the variable manufacturing cost of the pure EV is moderate, the firm with a lower technology capacity for improving the energy-saving level of the FV (i.e., firm 2) will produce the pure EV while the other firm (i.e., firm 1) produces the energy-saving FV, and the converse is not true. In this case, the decreasing variable manufacturing cost of the pure EV will benefit firm 2 and make firm 1 lose in a competing context. In particular, both firms would charge lower retail prices as the variable manufacturing cost of the EV decreases. In addition, we find that although the consumer subsidy could reduce the purchasing cost for the consumer and promote both firms to produce higher energy-saving level vehicles, a firm can still reduce its retail price under certain conditions because of the competition between the two firms. Finally, we prove that the consumer subsidy can be always beneficial to the environment, while it may hurt the consumer surplus and the firms’ profits under certain conditions. The results provide suggestions for governments to adopt an appropriate consumer subsidy program from perspectives of the consumer, environment, and economy.

The Selection of Green Technology Innovations under Dual-Credit Policy

In the pressure of excessive resource consumption and serious environmental pollution, government in China proposed a dual-credit policy to promote the production of green vehicles, such as energy-saving fuel vehicle (FV) and electric vehicle (EV). This study explores the firm’s selection of green technology innovations (GTIs) under dual-credit policy, including the energy-saving technology for FV and the technology for producing EV. We found that the firm’s technology capacity of improving the energy-saving level of FV plays an important role in affecting the firm’s selections of GTIs. Specifically, when the technology capacity is moderate, the firm chooses both types of GTIs to produce both EV and energy-saving FV, otherwise he will choose one type only. Moreover, no matter which GTI is selected by the firm, its pricing and environmental efforts decisions keep the same. With the dual-credit policy, we found that it could encourage the production of the EV under certain conditions. Besides this, increasing the green credit of EV can align the economic and environmental interests while increasing standard energy consumption has conflicts in both interests. In particular, when the firm offers FV only or both EV and FV, increasing the price of credit has conflicting interests in economy and environment. However, when the firm offers EV only, increasing the price of credit could improve the firm’s profit without hurting the environment.

Energy-saving and pricing decisions in a sustainable supply chain considering behavioral concerns.

With the rising environmental concerns among consumers all over the world, sustainability has received considerable attention, and numerous enterprises are adopting various practices such as investing in energy-saving to improve sustainability in supply chains. However, many previous researches always assume that decision makers are perfectly rational and neglect the behavioral concerns of decision makers. This paper considers a two-stage sustainable supply chain with behavioral concerns in order to develop more realistic models, and mainly focuses on the energy-saving and pricing decisions in the decentralized system, as well as how to improve energy-saving level and profits. We develop decentralized decision-making models under two types of behavioral concerns: fairness concern and risk aversion, and derive the optimal strategy for each member with a Stackelberg game in which the manufacturer acts as the leader. The effect of the behavioral concerns on the optimal decisions and corresponding profits is discussed in detail. Theoretical analysis verified by numerical experiments shows that the fairness behavior always causes a negative effect on the manufacturer, total supply chain, and energy conservation, while it could benefit the retailer in profits. The risk aversion behavior always benefits the manufacturer, total supply chain, and energy conservation, whereas it could make the retailer suffer. Note that both the optimal energy-saving level and corresponding profit of the total supply chain under two types of behavioral concerns are lower than that in the centralized system, thereby we propose a revenue-cost-sharing contract to coordinate the supply chain, under which both the manufacturer and the retailer can achieve a win-win outcome and the energy-saving level can be improved. In addition, some managerial implications through our analytical and numerical results are summarized in this paper.

Heat-transfer distribution optimization for the heat-integrated air separation column

The heat-integrated air separation column (HIASC) is an advanced energy-saving technology for the cryogenic air separation process, although a large capital investment is required for installed heat exchangers. These heat exchangers have a location-dependent effect upon the separation which leaves room for optimization. This paper, therefore, aims to optimize the heat-transfer distribution of HIASC regarding minimum heat exchanger costs while maintaining the low energy consumption level. Results indicate that the heat-transfer tends to concentrate at both ends of the column. The influence of operational parameters is further studied by the idea based on the liquid-vapor ratio. Finally, an optimal HIASC with respect to the minimal heat exchanger investment is obtained, and the heat exchanger costs are reduced by 44.4% compared with the uniform distribution with a similar energy-saving level.

International Real Estate Review

Many countries have implemented an energy labeling system that displays the energy savings performance of buildings. However, previous studies have reported mixed findings on the effectiveness of this system. This study is undertaken in Japan to assess whether energy labels are effective and validate the significance of the label design. We use an online survey to determine the effects of energy labels on target consumers. We choose two energy label designs: one with a stairs rating form design and the second with a rating scale of the energy efficiency. Adopting a within-subjects method, each respondent is shown both designs and asked to evaluate the energy-saving level based on the labels. Cross-tabulation confirms the positive effects of labeling on energy-savings levels, which are amplified by increasing the level of the reference point. The highest insulation performance level in Japan complies with a law enacted back in 1993; the results show that greater effects can be realized by increasing the level of the reference point. A logistic regression analysis shows that energy labels with the stairs rating have a negative influence, while labels with a rating scale are preferred based on ease of understanding by the respondents. This suggests that energy labels that offer a rating scale can contribute to facilitating energy savings, although there are problems with the comprehension of the gradation colors which need to be further examined. These results can act as a guideline towards optimal designs of the upcoming task of modifying the energy labeling system in Japan.

Understanding and Practice of Room Temperature Control Method Based on Energy Saving Reconstruction of Public Buildings

In order to respond to national energy conservation and environmental protection policies, green building development strategies should be implemented in urban public buildings construction, and large-scale project energy-saving renovation plans should be implemented from the perspective of energy conservation. Different projects can adopt different energy-saving control methods according to actual conditions and adopt different control strategies, but the ultimate goal is to change the current situation of large energy consumption, high utilization efficiency, noise pollution, water pollution and air pollution emissions. Building energy-saving renovation and technical control, effectively improves the building energy-saving level, achieves energy-saving and consumption-reduction goals, and gives full play to the value of various resources. At the same time, the energy-saving renovation project can also help enterprises to obtain the maximum economic and social benefits and promote the sustainable development of the construction industry. In view of this, this paper will talk about how to achieve energy-saving goals in the energy-saving renovation of public buildings from the aspects of energy-saving design of indoor supporting facilities, energy-saving design of walls, energy-saving design of doors and windows and roofing energy-saving design, and how to achieve reasonable control of room temperature.

Pricing policies in a dual-channel supply chain considering flexible return and energy-saving regulations

Due to the consistent growth of energy consumption and its impacts on production costs and the environment, governments have recently begun to devise and implement various energy-saving (ES) strategies. This paper studies the optimal pricing decisions in a dual-channel supply chain (SC) —consists of a manufacturer and a retailer— under different government intervention policies, namely ES, revenue seeking, social welfare, and sustainable development. We develop an extended dual-channel SC model under flexible return policies, including full-refund via the direct (i.e., manufacturer) channel, the indirect (i.e., retailer) channel, and both direct and indirect channels. A dynamic multi-level Stackelberg game approach is used to examine the SC interactions and characterize the return strategy, optimal pricing, and ES level decisions under different scenarios. The results show that employing full-refund via the indirect channel policy under price incentive schemes not only maximizes the profit of dual-channel SC but also satisfies the government’s objective functions. In contrast to other intervention policies, the revenue seeking policy does not necessarily improve the social welfare and energy saving level unless the government budget is increased.

An energy-saving bottleneck diagnosis method for industrial system applied to circulating cooling water system

Research on energy-saving retrofits of the existing industrial systems can effectively improve the systems’ energy-saving level and increase company revenue. The energy-saving bottleneck diagnosis for systems is the foundation of the energy-saving retrofit design. The diagnosis also aims to yield a more targeted energy-saving retrofit, thus ensuring the energy-saving effect and investment income of the transformation project. Therefore, this paper proposes a new method to diagnose the energy-saving bottleneck of the existing industrial systems. First, the energy-saving bottleneck diagnosis is decomposed into two parts: the diagnosis of energy-saving bottleneck units and the diagnosis of energy-saving bottleneck factors. Then, the energy density decomposition method is improved and a multi-mode energy efficiency density decomposition method is proposed. Next, an energy-saving bottleneck diagnosis method for industrial systems based on multi-mode energy efficiency density decomposition and an orthogonal test method is proposed. The proposed method can analyze the energy-saving potential of existing systems, accurately locate energy-saving bottlenecks, and avoid the dependence on a large amount of expert experience or complete production data in the existing methods. Finally, the proposed method is applied to an actual circulating cooling water system and the system energy-saving bottleneck diagnosis is realized, thus verifying the practicability of the method.

Design and Implementation of Energy Saving Management System Based on Data Mining

With the acceleration of urbanization, various items have generated a large amount of energy consumption on the basis of intelligent control, which has aroused widespread concern. Energy conservation has become an important direction of society. Colleges and universities are an integral part of society and a large energy consumer. Therefore, energy conservation management in colleges and universities is an important content. At the same time, designing energy-saving management systems in colleges and universities can not only meet the needs of energy-saving supervision in colleges and universities, but also deepen the significance of building a resource-saving concept into students. Through the construction of energy-saving management, it can realize the supervision of campus energy consumption, and further provide reliable data support and effective solutions for the school's energy-saving management level.

A Case Study for large-scale nearly zero energy retrofits of existing office building in Beijing

This paper studied the retrofit project of an existing office building in Beijing to meet the requirements of nearly zero energy buildings. The office building is the first retrofit nearly zero energy building project in China. There are technical difficulties under the constraints of the building and resources. In order to study the technical solutions applicable to the project, we analyzed the suitability of different energy-saving technologies based on the resources and characteristics of the project. Then we obtained the key energy-saving factors. This paper also discussed the energy saving effects of different energy efficiency technology solutions, proposing an optimized nearly zero energy technology solution and verifying the energy-saving level of the optimized plan. Compared with normal new constructions complied with national energy efficiency standard, the energy efficiency of this retrofit building increased by 60%.

Cost-Sharing Contracts for Energy Saving and Emissions Reduction of a Supply Chain under the Conditions of Government Subsidies and a Carbon Tax

To study the cooperation of upstream and downstream enterprises of a supply chain in energy saving and emissions reduction, we establish a Stackelberg game model. The retailer moves first to decide a cost-sharing contract, then the manufacturer determines the energy-saving level, carbon-emission level, and wholesale price successively. In the end, the retailer determines the retail price. As a regulation, the government provides subsidies for energy-saving products, while imposing a carbon tax on the carbon emitted. The results show that (1) both the energy-saving cost-sharing (ECS) and the carbon emissions reduction cost-sharing (CCS) contracts are not the dominant strategy of the two parties by which they can facilitate energy savings and emissions reductions; (2) compared with single cost-sharing contracts, the bivariate cost-sharing (BCS) contract for energy saving and emissions reduction is superior, although it still cannot realise prefect coordination of the supply chain; (3) government subsidy and carbon tax policies can promote the cooperation of both the upstream and downstream enterprises of the supply chain—a subsidy policy can always drive energy saving and emissions reductions, while a carbon tax policy does not always exert positive effects, as it depends on the initial level of pollution and the level of carbon tax; and (4) the subsidy policy reduces the coordination efficiency of the supply chain, while the influences of carbon tax policy upon the coordination efficiency relies on the initial carbon-emission level.