Isoparaffins are the branched chain alkanes that are used often in the extraction, alkylation and polymerization processes. Their characteristics such as low odor, nonpolar and purity make them applicable for various polymerization processes. They are widely used in slurry polyolefin polymerization. They are also used in various applications including polysiloxane molding, PTFE dispersions and as carriers for the catalysts used in the polymerization process. The technical properties of Isoparaffin can also impart the characteristics of low surface tension and the high oxidation stability for coatings and paint applications. Isoparaffin Isoparaffin Solvents,Isoparaffin Volatile Oil,Isoparaffin Oil Liquid,Low Aromatic Isoparaffin Shenyang East Chemical Science-Tech Co., Ltd. , https://www.eastchemy.com
Air source heat pump mainly by the compressor, expansion valve, fin heat exchanger, casing heat exchanger composed of the four major components, through the input of electrical energy to drive the compressor, the motor doing work, the fin heat exchanger to achieve endothermic, Sleeve heat exchanger radiating process, the heating effect of up to 380%, is the most energy-efficient heat source equipment, the use of the process, safety, environmental protection, high efficiency is its main feature. What are the advantages and disadvantages of the four major components of air source heat pump? 1, heart parts - compressor Compressor as the heart of air-source heat pump components, the equivalent of the computer's CPU, the heart of the human body, it can drive the flow of refrigerant through it, to achieve thermal expansion and contraction process, and let the refrigerant evaporation Heat, condensation of exothermic physical changes, the current compressor brands have Copeland compressors, Hitachi compressors, Sanyo compressors, Daikin compressors, known as the industry's four brands, in the heat pump industry, Copeland brand compression The best machine. 2, throttling device - capillary electronic expansion valve and thermal expansion valve throttle can usually be divided into capillary throttling, thermal expansion valve throttling (internal balance, external balance) and electronic expansion valve throttling, by changing the pressure of the refrigerant Change, so that the refrigerant liquefaction and gasification process, the degree of superheat or inlet and outlet air temperature, return air temperature and its setting a number of parameters such as detection and data acquisition, the microprocessor processing, the control expansion valve The opening to meet the system load requirements. Electronic expansion valve has the advantage of precise control of refrigerant flow, so as to achieve precise control of evaporation temperature. Usually used in places where temperature control accuracy is relatively high. Electronic expansion valve can work above -70 ℃, but the lowest thermal expansion valve can only reach -60 ℃. The capillary is used in a small refrigeration system (simple structure, not adjustable, after all, the capillary is only a small brass only); expansion valve is used in large and medium-sized refrigeration system (the structure is relatively complex, adjustable), the refrigerant Flow control in addition to controlling the evaporator, but also can be used to adjust the condenser. When the evaporation conditions permit, if the condensing pressure is too high, the expansion valve can be properly closed to reduce the flow of refrigerant in the system and reduce the condenser load, thereby reducing the condensing pressure and realizing the efficient and reliable operation of the air-to-water heater unit. 3, the exothermic components - casing heat exchanger casing heat exchanger is part of the heat transfer fluid to the water carrier, the choice of high-efficiency threaded copper tube, outsourcing of treated galvanized steel pipe to achieve a refrigerant water The process, so that high temperature refrigerant gas full contact with water to achieve better heat transfer. The advantages of casing heat exchanger: ◆ Simple structure, heat transfer area increase and decrease freely. Because it consists of a combination of standard components, installation without additional processing. ◆ high heat transfer efficiency. It is a pure countercurrent heat exchanger, but also can choose the appropriate cross-sectional size, in order to increase the fluid velocity, increase the heat transfer coefficient of the fluid on both sides, so it's heat transfer effect. Liquid - liquid heat transfer, the heat transfer coefficient of 870 ~ 1750W / (m2 • ℃). This is particularly suitable for high pressure, low flow, low heat transfer coefficient of heat transfer fluid. The disadvantage of the tube-type heat exchanger is the large area; heat transfer area per unit of metal consumption, about 5 times the shell and tube heat exchanger; pipe joints and more easy to leak; large flow resistance. ◆ Simple structure, large working adaptability, convenient heat transfer area increase and decrease, both sides of the fluid can increase the flow rate, so that both sides of the heat transfer surface can have a higher heat transfer coefficient. The disadvantage is that the unit heat transfer surface of the metal consumption is large, in order to increase the heat transfer area, improve heat transfer effect, the outer wall of the inner tube can be added to all forms of fins, and set in the inner tube scraper disturbance device, In order to adapt to high viscosity fluid heat exchanger. Disadvantages of the bushing heat exchanger: ◆ Maintenance, cleaning and demolition are more troublesome, easy to cause leakage in the removable connection. ◆ In production, there are more choices of materials. Due to the fact that most of the casing heat exchangers are not allowed to be welded in the inner pipe, welding will cause thermal expansion and cracking, while most of the casing heat exchangers will save space. , Curved system, made of snake coil plate form, so there are more special corrosion-resistant materials can not be normal production. ◆ casing heat exchanger has not formed a unified domestic welding standards, all enterprises are based on experience in other heat exchangers choose the welding method, so the casing heat exchanger welding, there are all kinds of problems commonplace, you need to always pay attention Inspection, maintenance. 4, the absorption of air parts - fin heat exchanger fin heat exchanger membrane mainly adopts aluminum foil, bridge ventilation system, so that the air full contact with the heat transfer area, more efficient absorption of heat in the air components. The characteristics of the fin heat exchanger: ◆ High heat transfer efficiency, due to the fin on the fluid disturbance so that the continuous rupture of the boundary layer, which has a larger heat transfer coefficient; the same time due to the separator, thin fins, with high thermal conductivity , So that makes plate-fin heat exchanger can achieve high efficiency. ◆ Compact, due to the expanded secondary surface of the plate-fin heat exchanger, its surface area can reach 1000m2 / m3. ◆ Lightweight, compact and mostly made of aluminum alloy. Now steel, copper, composite materials, etc. have also been produced in batches. ◆ Counterflow, wave tide, multi-stream flow, Different heat transfer conditions. Through the unit in series, parallel, series and parallel combination of heat exchange to meet the needs of large equipment. Industry can stereotypes, mass production to reduce costs, through the building blocks to expand interchangeability. Asia Fluid Network () Editor: Huang Nengwen, QQ: