Heat Preservation Performance Research Articles

Enhanced thermal insulation performance of polyethylene glycol-based polyurethane/W-doped VO2 composite phase change coating

Polyurethane (PU) is widely used in construction, fabric, leather and other fields due to its advantages of good heat resistance and high strength. However, there are few reports on the introduction of composite phase change materials into PU emulsion to synergistically improve its thermal insulation performance. In this paper, W-doped VO2 (W-VO2) particles were first prepared by hydrothermal method. Then, polyethylene glycol 1000 (PEG1000) was used as a soft segment to prepare polyethylene glycol-based polyurethane (PEG-PU) emulsion by prepolymerization dispersion method. Finally, W-VO2 was added to obtain PEG-PU/W-VO2 composite emulsion and film. Based on a series of results, the phase transition temperature of W-VO2 decreased from 67.7 °C to 52.2 °C. Furthermore, sunlight simulation experiments demonstrated that the thermal insulation performance of PEG-PU/W-VO2 composite film was significantly improved under the synergistic effect of PEG1000 and W-VO2. Specifically speaking, compared with PU film, the infrared isolation rate of PEG-PU/W-VO2 composite film increased by 59.3 %. Meanwhile, the infrared reflective and heat preservation performance increased by 20.5 °C and 15 °C, respectively. In conclusion, the development of this research is helpful for the development of thermal insulation coating, which is of great significance to meet the current needs of society.

Preparation and characterization of graphene antibacterial phase change energy storage viscose fibers

In this work, viscose fiber with antibacterial and phase change energy storage was made by microcapsule technology and wet spinning. Graphene oxide was used to enhance the thermal conductivity and antimicrobial properties. The heat preservation performance of graphene antibacterial phase change energy storage viscose fiber was determined by flat type fabric temperature protector and differential scanning calorimetry. The result of heat preservation test shows that the fiber has a good heat preservation property The antibacterial property, far-infrared property, mechanical properties, and the structures were also characterized. The enthalpy of exothermic & endothermic phase transition reached about 10 mJ/mg. According to the result of antibacterial test, the fiber had good antibacterial properties. The distribution of phase change microcapsules and graphene in fibers was analyzed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The strength and elongation of antibacterial phase change viscose fiber were found suitable for underwear garments fabrics and filling storage sheet. Combined with the electron microscope photograph and strength test results, the addition of graphene and phase change microcapsules has little effect on the mechanical properties of fibers, and can be used for industrial production.

Green, Sustainable Architectural Bamboo with High Light Transmission and Excellent Electromagnetic Shielding as a Candidate for Energy-Saving Buildings.

Currently, light-transmitting, energy-saving, and electromagnetic shielding materials are essential for reducing indoor energy consumption and improving the electromagnetic environment. Here, we developed a cellulose composite with excellent optical transmittance that retained the natural shape and fiber structure of bamboo. The modified whole bamboo possessed an impressive optical transmittance of approximately 60% at 6.23mm, illuminance of 1000 luminance (lux), water absorption stability (mass change rate less than 4%), longitudinal tensile strength (46.40MPa), and surface properties (80.2 HD). These were attributed to not only the retention of the natural circular hollow structure of the bamboo rod on the macro, but also the complete bamboo fiber skeleton template impregnated with UV resin on the micro. Moreover, a multilayered device consisting of translucent whole bamboo, transparent bamboo sheets, and electromagnetic shielding film exhibited remarkable heat insulation and heat preservation performance as well as an electromagnetic shielding performance of 46.3dB. The impressive optical transmittance, mechanical properties, thermal performance, and electromagnetic shielding abilities combined with the renewable and sustainable nature, as well as the fast and efficient manufacturing process, make this bamboo composite material suitable for effective application in transparent, energy-saving, and electromagnetic shielding buildings.

Study on property control of intercalated melt-blown nonwovens

Melt-blown nonwovens have fine fiber diameter, excellent filtration performance, small pores, and large specific surface area. However, the fluffiness of the material is not good enough. Adding conventional fibers into the melt-blown material can increase the thickness and fluffiness of the material, and improve the sound-absorbing performance and heat preservation performance of the material. To study how much fiber can be added to make melt-blown nonwovens better, grey correlation analysis is used to explore the influence of intercalation rate on each parameter. BP neural network is used for training, with process parameters as the input index and structural variables as the output index, and the results are obtained. According to the principle of statistics, the data of the results are analyzed and the process parameters of the highest filtration are obtained. Finally, the random forest regression model is used to establish the objective programming function to predict the added constraints.

Construction and Analysis of 3D Printer Exhaust Gas Treatment Device

With the rapid development of 3D printing technology, 3D printers have been applied in many fields. However, 3D printers with resin or plastic wires produce toxic exhaust (mainly VOCs), which may pose a great threat to the human body and the environment. In order to solve the problems above, this paper proposes a method of treating toxic exhaust gas by using heat-excited oxide semiconductors, and designs a device for treating toxic waste gas. From the aspects of force, heating performance and heat preservation performance, the feasibility of designing the device is verified through simulation analysis. On this basis, a physical device was built and a series of experiments were carried out. The experimental results show that after 10 minutes of treatment by the physical device, air quality from the exhaust outlet of the unit changed from heavily polluted to excellent, and the conclusion is drawn that the device can effectively deal with toxic waste gas. Briefly, the device can be applied to the waste gas treatment of 3D printers with resin or plastic wires, which has certain portability and can be used for the waste gas treatment of other equipment as well.

Thermal performance simulation of nano material modified fly ash light energy-saving wallboard in assembly building

Nowadays, China's urbanized buildings are prominent, and the building area continues to grow. The study of keeping the temperature of the building walls constant has become an indispensable key standard for building energy conservation. The purpose of this paper is to simulate and study the thermal energy performance of nanomaterial modified fly ash lightweight energy-saving model in prefabricated buildings. In this paper, in the selection of nanomaterial modified fly ash technology, the finite element simulation technology is adopted to study the thermal insulation effect of nanomaterial modified fly ash in building materials, and it also plays a guiding role in the actual work. In the experiment of improving fly ash lightweight and energy-saving wallboard with nanomaterials, we set up two groups of controlled experiments, namely modifying fly ash with traditional materials and modifying fly ash with nanomaterials. By comparing the heat preservation and heat insulation performance of modified energy-saving wall panels in prefabricated buildings. The results show that the nano-material modified fly ash foamed concrete, as 140 mm thick fabricated wall panel, has a good inhibitory effect on temperature transfer in the simulation of heat transfer. Under the condition of air-conditioning heating in winter and cooling in summer, the temperature difference between the inner surface temperature of the wall envelope (16.32 °C in winter and 23.25 °C in summer) and the indoor temperature (15 °C in winter and 23 °C in summer) is less than 3 °C. Therefore, the flyash lightweight energy-saving wallboard modified by nanomaterials can play a role in heat insulation and show good heat insulation characteristics in prefabricated buildings.

Effect of different catalysts on recovery and reuse of waste polyurethane rigid foam

The sharp increase of waste polyurethane rigid foam has caused great harm to the natural environment. Ethylene glycol (EG) and propylene glycol (PG) was the alcoholysis agents, and KOH and Zn3[Co(CN)6]2(DMC) were used as catalysts for alcoholysis of waste polyurethane rigid foam. Regenerated polyols were prepared. The effects of different catalysts on the infrared, viscosity and hydroxyl content of alcoholysis products were discussed. Regenerated polyurethane rigid foam was prepared from alcoholysis products and analyzed by compression strength, thermal conductivity, water absorption, scanning and thermogravimetry. The effects of different catalysts on the recycling of waste polyurethane rigid foam were studied. The experimental results show that DMC catalyst is more effective than KOH catalyst under the same conditions.The alcoholysis product of DMC system has lower viscosity and higher hydroxyl content, which is more suitable for the preparation of regenerated polyurethane rigid foam., The compressive strength of the prepared regenerated polyurethane rigid foam is 254 Kpa, and the thermal conductivity is 0.0213 W m−1·K−1 when the amount of DMC added is 0.04%. Meanwhile, the regenerated polyurethane rigid foam has good hydrophobicity, excellent heat preservation performance, complete cell morphology and good thermal stability. It can replace the traditional polyols to prepare the regenerated polyurethane material which meets the national standard ‘rigid polyurethane foam for building insulation’ (GB/ T21558-2005).

Design of non-magnetic temperature control system for atomic vapor cell of atomic magnetometer

In order to make the atomic magnetometer work, the heater of the atomic vapor cell must ensure that the temperature can be accurately controlled and the magnetic noise should be reduced as much as possible. This work proposed a non-magnetic heater and designed a corresponding temperature control system. It shows that the heater structure has good heat preservation performance and so, control of the heating process is made easy. The test results indicate that the fluctuation range of vapor cell temperature is less than 0.018°C, 0.015°C and 0.006°C respectively at 40°C, 50°C and 60°C. The effect of heater on the magnetic field cannot be observed by fluxgate magnetometer HS-MS-FG3LN-100 (<300pT).

Preparation and properties of solid waste based lightweight plastering gypsum

The lightweight plastering gypsum with excellent heat preservation performance was prepared from β-hemihydrate gypsum obtained by calcining desulfurization gypsum, the polyurethane foam waste modified with water glass, and a composite auxiliary agent composed of ground steel slag and granulated blast-furnace slag. The density of the product is 762.3 kg/m3, the initial setting time is 150 min, the final setting time is 205 min, the flexural strength is 3.1 MPa, the compressive strength is 6.8 MPa, and the thermal conductivity is 0.098 W/(m⋅K).

Thermal Properties of Carbon Fiber-Reinforced Lightweight Substrate for Ecological Slope Protection

A new ecological substrate is proposed to achieve a desired electric conduction and heating to protect the slope plants from freeze injury. Expanded polystyrene (EPS), cement, carbon fiber, graphite, and raw soil are the main components of the ecological substrate. The electrical conductivity, heating efficiency, thermo-sensitivity, and heat preservation of the substrate are experimentally investigated. The result shows that the addition of carbon fiber could significantly decrease resistivity of substrate, but the effect of fiber content exceeding 3% on the resistivity of substrate becomes insignificant. Conductive fine materials (i.e., carbon fiber and graphite powder) covering the surface of EPS would result in a significant reduction of the global resistivity of non-dry substrate, but it could only slightly affect the counterpart of the completely dry substrates. The substrate could hardly be formed when the EPS content exceeds 4%. As EPS content increases, the contact surface decreases and the resistivity of the substrate increases. The peak temperature at 30 min of substrate without root is higher than that of substrate with plant roots. Nevertheless, the temperature alteration ratio below 40 °C of substrate with plant root is nearly the same as its counterpart in the substrate without roots. The resistance of the substrate with plant roots increases with the temperature. The resistance of rootless substrate decreases by the heat action of the loosely bound water. EPS particles improve the heat preservation performance of substrate, but the heat preservation performance of substrate degrades with the growth of plants.

Phase Change Material Used for Masonry Joints to Reduce the Thermal Bridge Effect.

In this paper, a numerical calculation and application analysis of composite phase change material masonry mortar applied to wall parts are performed during the research process. Instead of the conventional “sandwich” phase change material wall, our research group mainly uses phase change materials in the wall parts to build masonry joints to reduce the thermal bridge effect. The influence of masonry joints on the heat transfer of the wall is demonstrated. A quantitative description of the transient heat transfer coefficient is obtained to measure the heat preservation performance of the phase change material wall. Furthermore, the influence of different proportions of phase change materials on the wall heat transfer in different external environments is discussed, supplemented by the influence of the working range and sensitivity on the heat transfer. In summary, the use of phase change materials in the construction of masonry joints is a great innovation for conventional “sandwich” phase change material walls, optimizing the form, the thermal bridge effect and the heat preservation performance of wall parts. The quantitative description of the transient heat transfer coefficient expands the development of wall heat transfer theories. In addition, the conclusions are of great guiding significance for the structure and the phase change material’s blending proportion for the innovative heat preservation phase change material wall.

Determination of Heat Transfer Coefficient of Two Insulated Cotton Based on Wall Framing

The heat preservation performance of the light wood frame construction wall directly affects the energy saving effect of the light wood frame construction. In order to strengthen the research of the thermal performance of the light wood structure wall and sandwich wall, in this paper, the heat transfer coefficient of glass-insulated cotton with two kinds of materials was measured in the exterior wall of the same light-weight wooden structure through field test method for heat transfer coefficient of construction so as to compare the test value and theory of the wall insulation coefficient Value, and preferably a thermal insulation cotton filling material. The conclusion shows that the wall filling material of guardian glass insulation performance is better than the Owens Corning Glass insulation cotton, and the former is adapted to the area of hot summer and cold winter and hot in summer and warm in winter, which is suitable for the hot summer and warm winter area. This paper is helpful to promote the energy saving optimization design of the wall structure of the light wood frame construction, and the engineering application value is high. Calculating the heat-conducting value of light wood structure wall, and the calculated values of the temperature of the constituent materials are comparable with the measured values actually, and the composite material theory can be used to predict the heat-conducting property of wood structure construction. The above is mentioned help to improve the level of on-site testing technology of heat-conducting, and provide a useful reference for the energy-saving insulation design work for light wood structure wall in our country, and this study has a high engineering application value.

Performance investigation of salt gradient cylindrical solar pond integrated and nonintegrated with evacuated tube solar collectors

In this study, the energetic and exergetic efficiencies of a salt gradient cylindrical solar pond (SGCSP) that integrated and nonintegrated evacuated tube solar collectors (ETSCs) are investigated to improve daily heat preservation performance of the heat storage zone (HSZ). The integrated system is consisted of an SGCSP and four ETSCs. The SGCSP has a surface area of 2 m2, a depth of 1.65 m, salty water layers at different densities, and HSZ in which the cylindrical serpentine type heat exchanger (CSHE) is located. Thus, the daily effects of the heat storage performance of both the ETSCs and the SGCSP in the winter season was determined experimentally. The analysis of the data regarding the efficiencies of the system is investigated separately by means of experimental studies where the SGCSP is integrated and nonintegrated with the ETSCs. The number of ETSCs integrated with SGCSP is increased to 1, 2, 3, and 4, respectively, and each of the five different experimental systems is performed separately. The temperature distributions of the integrated system are measured by a data acquisition system on 11 different points per hour. The efficiencies are calculated using the data obtained from these studies. Consequently, the energetic and exergetic efficiencies of the SGCSP are obtained without collectors as 10.4% and 4.3% and with one collector as 12.83% and 6.15%, with two collectors 14.88% and 8.25%, with three collectors 16% and 9.35%, and finally with four collectors 16.94% and 10.3%, respectively. Furthermore, the theoretical efficiencies are found to be consistent with the experimental results obtained by increasing the collector numbers.

Synthesis, characterization and modeling of new building insulation material using ceramic polishing waste residue

A new building insulation material was produced using ceramic polishing waste residue (CPR) as a main raw material and synthesized at the sintering temperature range of 1010–1200°C. Silicon carbide (SiC), tri-sodium phosphate dodecahydrate (Na3PO4·12H2O) and magnesium oxide (MgO) were chosen as additive agents. Effects of the additive agents and sintering temperature on the bulk density and the pore size were systematically investigated, and the corresponding mechanism was also discussed. The results showed that SiC played a key role in the formation of pores due to its decomposition at the proper temperature. The addition of Na3PO4·12H2O and MgO both decreased the expansion temperature of the sample to different extent and resulted in the pronounced variation of bulk density. The thermal conductivities of the samples with different bulk density were predicted using a developed random simulation model and the results were in well accordance with the measurement data by a guarded hot plate apparatus. These results indicated that the present sample has low density and good heat preservation performance, which is expected to be applied as the building insulation material.

Study on Fire Prevention of Wall Insulation Organic Materials

This article described the technical progress of the wall insulation organic materials and analyzed other relevant factors in recent years about the insulation materials policies changes and market changes. Through the above description and analysis, we presented new ideas of the future direction of development of organic insulation materials. Background In recent years, big fire moments remind the importance of fire safety all the time. The CCTV Building Fire in 2009, Shanghai Jiaozhou Road Fire in 2010 and Shijingshan Fire in 2013, let the public turn pale at the mention of a word about fire. These fires are all related to the wall insulation organic materials. In fact, it should be said that unqualified exterior wall thermal insulation materials and the lack of supervision measures led to a variety of fire accidents which can be avoided. Therefore, good flame retardant wall insulation organic materials and thermal insulation system are very important to reduce and prevent fire, and they are also fundamentally important ways to block and reduce the fire risk. At present, there are three kinds of wall insulation materials. The first type are the inorganic heat preservation materials, such as rock wool, glass wool, mineral slurry, etc., These materials belong to no combustible materials (class A fire), and there is no fire safety problems. The second type of wall insulation materials are composite materials, such as phenolic foam insulation materials, reaching flame retardant materials B1 level (fire). The third kind are the organic polymer insulation materials, such as molding benzene board (EPS), foaming benzene board (XPS), polyurethane (PU) . They belong to the combustible materials (B2 fire). This kind of material have the danger of fire. In our country the most widely used of wall insulation materials are the third class. Especially the EPS and XPS have good heat preservation performance, low price. And They are light and durable. But, this kind of materials have obvious disadvantages that they are so easy to burn, and release diffuse toxic or harmful gas in the combustion. Therefore, we should focus on hot spots about organic fire situation of wall insulation organic materials. Fire prevention progress of common wall insulation organic materials Polyurethane (PU) :

Evaluation and Measured Analysis by FTIR of Fiber Insulation Materials Used in Inflatable Mini Cold Storage

Thermal insulation performance is a key factor in evaluation of thermal insulation materials. The chemical structure of polyester fiber, bamboo fiber and polylactic acid fiber was analyzed, and thermal insulation properties of the samples were investigated in terms of the measured transmittance of IR with before and after treated. The results showed that the measured transmittance of IR of corn fiber was lower than polyester fiber and bamboo fiber. In addition, the measured transmittance of bamboo fiber changed obviously, polyester fiber had small changes, polylactic acid fiber almost had no change. Moreover, the measured transmittance had an increasing trend. The heat preservation performance decreased after the samples were treated.

Cotton Stalks Cement-Based Block Material and its Preparation Method

In Xinjiang, by making use of cotton stalks after cotton picked, people researched and developed a kind of walling material that is cotton stalks cement-based blocks, elaborated its preparation methods, and evaluated its technology effect of cotton stalks cement-based block material. Results show that the cotton stalks cement-based block material have good properties like wide source, easy processing and wonderful performance; by soaking cotton straw broken material with alkali liquor, made cotton straw plant fiber reinforced material and the cement matrix have good interface adhesion; the block material is provided with load-bearing, heat preservation performance and cracking resistance, it can be used for low-rise buildings bearing wallboard and retaining wall of multiple floors in cotton planting region.

Study on Thermal Insulation Solutions for Submarine Oil Storage in Offshore Gravity Platform

As application of gravity platform is increasing rapidly in marginal oilfields, the heat preservation performance of the submarine oil tank is becoming more and more important in offshore oil storage technology. In order to enhance heat preservation performance of the concrete oil tank to reduce energy consumption, three insulation solutions were proposed in this paper. Contrastive analysis shows that polyurethane solution can not only maximize economic benefits but also possess high engineering feasibility and environmental value.

The Experiment Study on How Medium Gas Affects Seawater Desalination Facility's Performance

A self-designed small size three-effect tubular still is used to conduct a study on the stills performance in the condition of different medium gases (air, oxygen, carbon dioxide and helium, namely a research about the steady state water-yielding capacity and heat preservation performance. The research concludes that when using carbon dioxide as the medium gas, the steady state water-yielding capacity of desalination facility is better at temperature of 80°and below, water-yielding rate can be as much as 0.6kg/h, which is increased by 18% compared of using air as medium gas; when using carbon dioxide as the medium gas, the heat preservation performance of desalination facility is better ,of which the average temperature is 2°higher than any other medium gas. Thus the system can perform better under the condition of medium gas of carbon dioxide without illumination.

Research on Temperature Distribution and Stress Distribution Model of Prefabricate Block Electric Furnace Roof

Electric furnace roof is an important device for electric steel making, whose heat preservation performance and life-span have a direct impact on the economic benefits of iron and steel enterprise. Considered contact behavior between prefabricate block, this paper establishes the complete CAD/CAE model of the electric furnace roof with finite element software based on the theory of transferring heating subject, and respectively calculates the stable temperature and stress field of the firebrick roof and the prefabricate block roof in last melting stage, as is advantageous to analyze the level and the distribution of temperature and stress of electric furnace roof.