First of all, I personally think that the "primary stage" of "building energy saving" is to put a cotton jacket on the house should be over. It is not only that this energy-saving method brings hidden dangers to building safety, but more importantly, this primitive, life-experienced energy-saving method is not the choice for scientific development in the 21st century.
Many people know that I have been researching "interface" energy-saving materials for more than ten years. Some people ask me very directly, what is the R value of "interface" energy-saving materials? We can imagine that if we set the thermophysical properties of the "maintenance system" as Z, and the thermal trajectories of the "interface" material as X, Y; if we can control the thermal shape of the environmental space at the two axes formed by the X and Y axes On the dimensional interface, what is the direct relationship between the X and y axes and the Z axis? As I said, building energy efficiency is actually not necessarily positively correlated with the thermal resistance of the maintenance system; that is, the higher the thermal resistance of the maintenance system, the more energy-saving it is; the key is to depend on the thermal diffusion capacity of the two-dimensional interface and the form of thermal conversion. What's more, the block materials that "wrapped" the maintenance system, the energy consumption of the pre-production process of raw materials was not included in the comprehensive evaluation of energy conservation.
Many people are interpreting "adiabatic system" in their own way, the conceptual description of this thermodynamic working condition; it is no longer the same when it is introduced into building energy efficiency. The real meaning of "adiabatic system" is to block and maintain the chemical properties and physical properties of heat exchange on both sides of the interface of the system, and strive to form an isolated state of the thermal state of adjacent physical spaces. This is the key to the energy saving of the "interface" material, and also the secret of the contribution of the "interface" material's thermal diffusion and thermal conversion to the energy saving of the building compared to the heat conduction of the maintenance system.
I suggest not to mention emissivity, reflectance, because it really has no direct relationship with the R value. I also recommend not challenging the ratio of the surface temperature difference between the front and back hot sides of a material to the intensity of the heat flow through the material into the back hot side, the relationship used to describe the thermodynamic properties of a material. Mr. Fourier's definition of thermal resistance is world-recognized and successfully applied in the field of modern high-end technology.
Due to the gap in understanding, "interface" energy-saving materials, including the "energy-saving paint" that many of our friends say, we need to systematically give a satisfactory explanation to the industry management in terms of theoretical and practical application effects, and give users the actual effect experience. Among them are It takes hard work and patience. Exaggerated, free from half-understood, or even hearsay, exaggerated, harmful to the development of the industry but not beneficial. I sincerely hope that everyone can form a joint force, climb high and look forward, and work hard to promote the steady and long-term development of "interface" energy-saving materials. "Building energy conservation" has become a major national policy, and more and more experts and scholars have joined the industry. Innovation and development science is the primary productive force. It is believed that the role of "interface" materials in replacing block materials in building energy conservation is Just around the corner.
To engage in building energy conservation, we must study what is "heat", the physical properties of heat, the characteristics of heat balance transfer, and the differences in the state of heat occurrence in different physical spaces. Without starting from the fundamentals of classical theoretical principles, it is difficult to grasp the reliability and accuracy of the technical route. "Adiabatic system" in thermodynamics is an isolated condition that describes the operation of an automobile engine. Cylinder pistons run thousands of times a minute, yet car engines are required to maintain the best point for gasoline combustion - 90 degrees. From this, we can think that there are other technical paths for building energy conservation besides conduction resistance and heat resistance? The physical form of "heat" is largely similar to "electricity"; before superconducting materials appeared, we probably only thought of insulating materials to prevent electric shock; however, superconducting protection makes it difficult for you to get electric shock. This is "blocking" The dialectical relationship with "sparse".
The thermal physical wave calibrates the performance properties of the heating material, and the frequency and amplitude of the physical wave determine the thermal morphological strength. It is no longer a cutting-edge science to influence the diffusion path and shape of thermophysical waves by the material microstructure. "Shifting" still has a lot to do; the key lies in material synthesis, and whether the technical route for material synthesis is accurate or not. For example, a month ago, a scholar at the University of California, Berkeley published a temperature-adaptive radiative coating in "Science", and TARC is the A temperature-regulating coating. That is to say, using different metal oxides and different microstructures can produce completely unexpected interface effects. The key is perseverance and continuous exploration.
I would like to share with you a PPT of mine. You can see in the picture that the physical parameters that characterize the bulk material and the interface material are completely different. We cannot use the same physical fitness standards because of track and field athletes and swimmers because they are all athletes. test. The prerequisite for thermal conductivity is thickness and time; and the thermophysical properties of interface materials have nothing to do with time or thickness. I have also explained this many times in industry exchanges. Some people understand it, and some people never understand . All communication channels are very important; otherwise, it will be difficult to reach a consensus. What is an "interface" material? In many cases a little science is required. Some people stubbornly call it "paint" because metal oxides need to be mixed on the wall through emulsion. However, fixing the "paint" with "reflection heat insulation" has become a cognitive formula that is difficult to crack. Metal oxides form a liquid suspension through an emulsion, is it a coating? Is "paint" a material with pre-existing properties? I have to make an analogy: For example, flour and rice flour need to be mixed with water to form dough, rice balls, and after dough, rice balls make noodles, flour cakes, rice noodles, and rice cakes; can it be said that flour and rice flour mixed with water can be called Is it "paste" regardless of whether the actual ingredient is flour or rice? In fact, water is only an auxiliary agent for noodles and rice. It does not affect the nutrition of rice and noodles, nor does it affect the edible properties of rice and noodles as ingredients. Similarly, the coating after the emulsion is applied to the wall depends on the synthesis of the metal oxide and its effectiveness against the thermal morphology of the physical space. Different metal oxides can block different thermophysical waves and have different physical properties, so He did not fully interpret it with just one sentence of "coating". The "interface" coating after consolidation has nothing to do with the emulsion.
Is it clear. The "ceramic" we mentioned, many people interpret it as silicon dioxide. Indeed, ceramics generally contain silicon dioxide, but the proportion is less than 10%. In nature, silicon exists very little in the form of single crystals. When citing ceramic expressions in material research, the molecular structure type is often considered, not necessarily its chemical composition. "Ceramic" is more appropriately seen as a silicate.