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Integrating combined cooling, heating and power (CCHP) system with biomass gasification is a sustainable distributed energy system to effectively utilize biomass resource and improve energy efficiency. In order to achieve a higher energy efficiency and more cost-effective operation, a thermoeconomic cost analysis method based on the exergetic cost theory is applied to the CCHP system based on biomass gasification. Firstly, the exergetic cost and thermoeconomic cost of all flows in the system are calculated in different operation modes. Moreover, a sensitivity analysis is presented to obtain the thermoeconomic cost variations of the products along with the influence factors, such as service life, interest rate, operation hours and biomass cost. The results indicate that the unit exergetic cost of electricity is 4.447, 4.445 and 4.447 for the summer, winter and transition season operation conditions, whereas the thermoeconomic cost is 240.004RMB/h, 257.905RMB/h and 270.811RMB/h, respectively, while for domestic hot water, these values are 14.822, 14.817, 27.086 and 33.361RMB/h, 35.769RMB/h, 166.284RMB/h, respectively. The unit exergetic cost of water for cooling and heating is 8.804 and 7.465, the thermoeconomic cost is 138.807RMB/h and 147.454RMB/h, respectively. From the sensitive analysis, the biomass cost is the most sensitive factor to the thermoeconomic cost of the products. The results also reflect that a combination of the thermoeconomic cost based on exergetic cost and sensitivity analysis method is a powerful and efficient tool for evaluating the performance of multi-product energy system. [ABSTRACT FROM AUTHOR]

Inner Mongolia locates in the very north of China, where there always be quite cold in winter. As a result of emphasizing on high indoor temperature, large amount of heating energy had been consumed in the past decades. In this research, the influence of occupant behavior, for instance, the dressing habit, window opening behavior and consumption customs on building heating energy consumption had been investigated. Field investigation, with the aid of other methods, such as design scene investigation method, are firstly prepared to be taken advantage of to seek out the information related to occupant behavior modes. Secondly, indoor and outdoor related environmental parameters of typical buildings were monitored. By means of our research, two typical behavior characteristics of Inner Mongolia occupants were found: 1) People opened windows for cooling purpose in winter; 2) They got accustomed to wear light in home as well as dissatisfied with comparatively proper indoor temperature admitted by national standard. The reason for that can be attributed to the inefficient heating cost allocation method, which should be further retrofitted in order to stimulate occupant energy conservation awareness. [ABSTRACT FROM AUTHOR]

This study proposes a combined cooling, heating, and power (CCHP) system driven by biomass and solar energy integrated with an organic Rankine cycle (ORC). Its exergy, exergoeconomic, and exergoenvironmental performances are investigated. First, the thermodynamic parameters of each material and energy flow for the proposed CCHP system are simulated using Aspen Plus. Second, the exergy and exergoeconomic performances of the system are investigated, and an exergoenvironmental analysis of the system is performed. The results show that the unit exergy costs (UEC) of domestic hot water, electricity generated by an internal combustion engine (ICE) and the ORC, and chilled/heated water under summer/winter conditions are 2.742/2.742, 6.713/6.629, 12.930/12.930, and 27.100/12.530 MW/MW, respectively, with corresponding unit exergoeconomic costs (UEEC) of 41.11/41.11, 124.40/139.20, 181.80/181.80, and 507.10/302.60 USD/MWh, respectively. Meanwhile, the corresponding environmental impact rates per exergy unit are 0.616/0.616, 2.988/3.023, 0.030/0.030, and 6.567/3.072 mPts/MJ, respectively. The results highlight the urgency to prioritize improvements to the solar collector performance to reduce the UEC of electricity generated by the ORC. The absorption chiller/heater, heat exchanger, and ICE exhibit significant potential for enhancing their exergoeconomic performance. Additionally, the gasifier, ICE, and ORC can be optimized to mitigate their environmental impact with relatively minimal exertion. [Display omitted] • A new solar- and biomass-driven CCHP system integrated with the ORC is proposed. • The biomass gasification, ICE, ORC and, AC are simulated and validated. • The exergy performance of each component of the proposed CCHP system is investigated. • Exergoeconomic and exergoenvironmental analyses are performed for the proposed CCHP system. [ABSTRACT FROM AUTHOR]

In order to realize sustainable development of the whole economic society, the evaluation of the energy efficiency level of energy consumption sectors (ECSs) is urgent and necessary. This study elaborated the concept of the energy efficiency improvement from the perspective of whole society to establish a macro-evaluating system (MES). Industry, transport, civil buildings are the three major ECSs in China at present. By analyzing the status of each energy consumption sector (ECS) and the relative energy efficiency technologies, a hierarchical evaluation model, including evaluation factors, sub-factors, weights for each factor and sub-factor, was proposed for each ECS. With the help of the Analytic Hierarchy Process with Delphi (AHPD) and Grey Correlation Degree (GCD) method, the comprehensive scores, namely, the weighted incidence degree was obtained. Three cases in Tianjin, China were taken as examples to prove the feasibility of the evaluation system. Typical cities, including Shenyang, Beijing, Wuhan, Guangzhou, Chengdu, Xi'an, located in different regions of China were evaluated and compared. Results demonstrated that the technical level was mainly influenced by policy and economic level. Recommendations for energy efficiency policy making and energy efficiency targets allocating were proposed for regions based on the evaluation results. [ABSTRACT FROM AUTHOR]

Highlights: [•] A modified bin method is adopted to propose and optimize the EER schemes. [•] A case study is presented to demonstrate the analysis procedures of EER schemes. [•] Pertinent EER schemes for HVAC systems are proposed for the object building. [Copyright &y& Elsevier]

Abstract: Indoor design air parameters regulated in current design standards are set on the basis of human thermal comfort without fully considering the building energy efficiency. This article analyzed the indoor design air parameters with investigation study and simulation study respectively from both views of thermal comfort and energy consumption. By conducting field testing in existing buildings and collecting design information from blueprints and description files, indoor air parameters of 140 public buildings in China were investigated. Typical public buildings (small office building, large office building and shopping mall) were selected for simulation study. Simulation models for three types of public buildings were established based on the investigation results in order to have assumptions better fit the actual situations. The relationship between PMV (predicted mean vote) and energy consumption of the simulation models was analyzed. From the analysis of the results of investigation and simulation, it could be seen that the design relative humidity in winter hardly influences the indoor thermal comfort and building energy consumption, while design relative humidity in summer, indoor air temperature and PMV values were all related to indoor thermal comfort level and building energy consumption. Recommend indoor design air parameters that contribute relatively low energy consumption and high comfortable level were also put forward to improve the current design standards. [Copyright &y& Elsevier]

Abstract: Geothermal energy has been successfully applied in many district heating systems. In order to promote better use of geothermal energy, it is important to analyze the operation strategy of geothermal heating system. This study proposes a comprehensive and systematic operation strategy for a geothermal step utilization heating system (GSUHS). Calculation models of radiator heating system (RHS), radiant floor heating system (RFHS), heat pump (HP), gas boiler (GB), plate heat exchanger (PHE) and pump are first established. Then the operation strategy of the GSUHS is analyzed with the aim to substantially reduce the conventional energy consumption of the whole system. Finally, the energy efficiency and geothermal tail water temperature are analyzed. With the operation strategy in this study, the geothermal energy provides the main heating amount for the system. The heating seasonal performance factor is 15.93. Compared with coal-fired heating, 75.1% of the standard coal equivalent can be saved. The results provide scientific guidance for the application of an operation strategy for a geothermal step utilization heating system. [Copyright &y& Elsevier]