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This research aims to explore a novel PCM that can satisfy the needs of vaccine cold chain logistics temperature zone (2–8 °C), with decyl alcohol (DA) and lauric acid (LA) chose to be eutectic. Considering the thermal conductivity and leakage of materials, DA-LA/EG composite phase change material (CPCM) with a mass ratio of 12:1 is prepared by the vacuum adsorption method. The thermal properties of DA-LA/EG CPCM are analyzed by DSC, cooling curve, Hot Disk, SEM etc. From the DSC graphs of DA-LA eutectic phase change material (EPCM), it is found that there is difference between the melting temperature and solidification temperature, which is defined as phase change hysteresis. The results indicate that the phase transition temperature of DA-LA/EG CPCM is 2.08 °C, with high latent heat and thermal conductivity of 188.71 J g−1 and 1.7527 W m−1 K−1, respectively. Due to the unique porous structure of EG, the thermal conductivity is 13.75 times higher than that without EG, which leads to the phase transition time shortened by 79.47%. Furthermore, DA-LA/EG CPCM shows excellent cyclic stability and chemical stability after 500 high-low temperature alternating tests. From TGA, the decomposition temperature of DA-LA/EG CPCM is 186.55 °C, higher than the working temperature range. The applicability is demonstrated by using the CPCM into an incubator. Overall, DA-LA/EG CPCM has good application prospects in vaccine cold chain logistics.

In recent years, the construction of enclosed material yard projects has becoming an urgent requirement to improve ecological environment and living environment quality. Thin membrane structures have been widely used in industrial building, especially for storage building roofs. Due to the thermal-optical properties of translucent thin fabric material, such as the absorption and transmittance of solar radiation, the indoor thermal environment is seriously disturbed. Moreover, membrane building structures are usually irregular. Compared with conventional buildings material, the translucent thin fabric material particularly responsive to changes in external environment conditions. As a result, the solar radiation heat gain calculation of membrane buildings is complicated. It is worth exploring measures to tackle this problem. Therefore, in order to solve the problem that the relevant thermal-optical parameter is difficult to obtain. The 13 thin membrane samples were tested and the thermal optical characteristic parameters were analyzed in this paper. A practical enclosed membrane structure building was selected as the research object. In addition, a solar radiation heat transfer model was established. The indoor solar heat gain under the action of solar radiation heat was calculated and the effect of different light transmittance and absorptance on the indoor radiation heat gain was studied. It can provide reference for heat gain calculation and ventilation design of membrane structure storage buildings.

Nowadays with the development of science, many new technologies are being introduced to the fabric membrane material fields. Membrane structures have been widely used in industrial storage building...

Based on the literature on the degradation mechanism and the change of micro-functional groups in the fermentation process of modified rice straw, this study aimed to solve the problems of low biogas production rate and poor stability of the biogas production system. In this work, mathematical equations were developed and combined with duck dung and rice straw mixed raw material to perform a fermentation test. The molecular micro-functional group changes of cellulose, hemicellulose, and lignin were studied to obtain the optimal ratio of mixed raw materials for fermentation and to explore the optimization mechanism of its fermentation biogas production. Experimental results showed that the optimal ratio of mixed raw materials was 2.8:1, and the inclusion of a suitable amount of Mn2+(concentration of 2 mol × L-1) was able to strengthen MnP activity and improve the ability of white-rot fungi to rupture β-O-4 bonds. A modification pre-treatment via activated carbon-based solid acid was performed, and the experimental group generated 15.8% more cumulative biogas than the control group. The biogas yield reached its peak when 300 g of inoculum was added to the pre-treatment at a concentration of 30%.

Phase change materials (PCMs) have great potential in the field of passive thermal management due to their high latent heat and approximately constant temperature property during phase transition. In this paper, a novel AlN-enhanced OBC/PA/EG composite is proposed. Here, olefin block copolymer (OBC) as a supporting matrix not only prevents the leakage of liquid paraffin (PA) but also endows thermally-induced flexibility to the composite phase change material (CPCM). The effects of various aluminum nitride (AlN) additives content on the thermal conductivity and phase transition enthalpy of CPCM are investigated. The results indicate that the addition of AlN can greatly enhance the thermal conductivity and insulating property of CPCM. Besides, the morphology structure, chemical compatibility, thermal properties of prepared CPCM are systematically analyzed by SEM XRD, DSC, and TGA. Then, in the heat storage and release experiment ranged from 0 to 80 °C, the CPCM containing 10, 20, and 30 wt% AlN can reduce the heating time by 30.3, 36.6, and 40.1% than without AlN, respectively. Finally, the effect of CPCM on battery thermal management system (BTMS) is investigated in five discharge-charge cycles. The results presented in this paper imply the novel composite PCMs are potential candidates for energy storage and thermal management system.

Compared with the conventional building structure, the translucent lightweight membrane structure with excellent material performance, good building performance and structural performance has attracted widespread attention. Generally, the analysis of the thermal environment of membrane structures is an interdisciplinary subject in terms of material properties, environmental performance and sustainability. In order to determine the typical and essential thermal characteristics of membrane structures, the thermal-optical properties of membrane materials, heat transfer properties and thermal behaviors of building envelopes with membrane structures were reviewed. The achievements and gaps of the research on indoor thermal environment of membrane structure buildings were summarized. In addition, some reasonable suggestions have been proposed for future research on the indoor thermal environment of membrane structure buildings.

Membrane structure has a very good application prospect in the field of industrial material storage because it can effectively reduce the dust pollution of open storage yard. However, architectural fabrics material can neither store heat nor insulate. In addition, the high solar heat absorption coefficient and the spontaneous heat dissipation of coal lead to a poor indoor thermal environment. At present, there is still a lack of studies on the indoor thermal environment of industrial buildings enclosed by fabric membranes. In order to study the indoor thermal environment and natural ventilation of such buildings, field measurements and simulation calculation were carried out. The influence of outdoor air temperature and solar radiation on the indoor thermal environment was analyzed based on the measured data. Furthermore, in order to make full use of natural ventilation, a natural ventilation model was established by using computational fluid dynamics (CFD). The influences of different ventilation areas and air vents heights on the indoor thermal environment were analyzed, the corresponding optimization and improvement methods were proposed in this paper.

The combustion characteristics of hydrochars from millet stalk (MS) and dilute-acid-impregnated millet stalk (AMS) were investigated by thermogravimetric analysis. The Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) isoconversional approaches were used to determine the activation energies of the hydrochars. The pre-exponential factors were estimated by the compensation effect. A new mixed-function was proposed to fit the derivative thermogravimetric (DTG) curves to describe the combustion behaviors of the MS and AMS hydrochars. The results showed that compared with MS hydrochar, AMS hydrochar presented better fuel properties, including a higher yield, higher carbon content, lower ash content and lower nitrogen content. The fuel ratio and specific surface area of AMS hydrochar were also higher than those of MS hydrochar. The combustion kinetics indicated that the average activation energy of MS hydrochar first increased and then decreased with increasing HTC temperature. In the case of AMS hydrochar, the average activation energy decreased from 142.5 and 138.6 kJ/mol to 111.7 and 105.1 kJ/mol, as determined by the FWO and KAS approaches, respectively, as the HTC temperature increased from 210 °C to 300 °C. The average activation energy of AMS hydrochar was lower than that of MS hydrochar due to dilute-acid impregnation. The simulated DTG curves were in good agreement with the experimental data, indicating that the reaction functions for both the MS and AMS hydrochars can be accurately described by the mixed-function model. The proposed mixed-function fitting method, together with the obtained kinetics data for the MS/AMS hydrochars, can facilitate the design and optimization of combustion and hydrothermal carbonization systems.

Introduces some principles and calculating method used for the problem of porous brick wall in new energy-saving area. Finite volume method is adopted to complete the numerical analysis of building blocks model. The SIMPLE algorithm is used to solve the equation of speed and pressure. Convection–diffusion subject uses second-order upwind format. Calculation mesh adopts the unstructured hexahedral style. A few examples calculated are given. The date comparisons between calculation and experiment are given up. Rectangular hole brick is affected more stronger than circle hole brick. The wall heat flux and wall temperature have been calculated. Thermal performance can be obtained through numerical calculation in the steady heat transfer, being very approximate from the experimental result. According to the calculation of temperature distribution in the brick, thermal performance can be successfully analyzed.

An experimental setup about solar ejector refrigeration is designed and built using HFC134a as working fluid in this paper. Based on Zhengzhou meteorological parameters, the hourly coefficient of performance(COP), energy efficient ratio(EER), cooling capacity and other parameter about the ejector refrigeration system have been researched with the solar radiation changed, The experimental data show that the hourly COP and EER of the system change constantly, and it has been influenced by the solar radiation, the ambient temperature, generator temperature, and condenser temperature et al., and the cooling capacity, heat transfer capacity about the exchanger, and generator temperature appear rise and fall in the research range. The average daily COP is 0.18 at the July 26, the average EER can up to 3.5. Keywords-Solar ejector refrigeration;Hourly performance; Solar radiation

Introduces the development and application research of load about air- conditioning based on BP neutral network. Connects some theory about BP neutral network and characters about bus air conditioning, and develops BP neutral networks for cooling load calculation of bus air conditioning. The results show the cooling load decrease 22.8 percent compare with steady calculation method. The BP neutral network is an effective cooling load calculation method, and the research can provide some theoretical evidence for optimizing holistic design about bus air conditioning.

Based on the VB program, establish a simulation program about the solar ejector system performance. The characteristic of entrainment ratio has been analyzed when the HFC134a, R290 and R718 are adopted as working fluid respectively. It is found that the entrainment ratio of R290 is the biggest over the range of operating conditions, and the entrainment ratio of HFC134a is the middle, and the R718's is the least. The entrainment ratio of the system increases with increasing of the generator temperature and evaporator temperature, and decreases with increasing of the condenser temperature in the research of operating range, and the influence of condenser temperature on the ejector refrigerant system is more than the generator temperature and evaporator temperature. The research will provide theoretical support for solar ejector refrigeration technology optimization design and extension.