The main type of Tape Measure is Steel Tape, followed by fiber tape, which is the tape that everyone often sees. Many people say it is a cloth ruler, and there is also a waist measurement ruler (tailor ruler/clothing ruler belong to this category). In southern China and Hong Kong, the tape measure is usually referred to as a soft ruler or a pull ruler. The material is PVC plastic and glass fiber, which can prevent the tape from being stretched during use. 3M Tape Measure,Vintage Tape Measure,Cheap Tape Measure,Durable Steel Measuring Tape Henan Liangjin Tools Co.,Ltd , http://www.liangjintools.com
What are the types of solar heat pump water heater? What are their characteristics?
Solar assisted heat pump usually refers to the system as a solar heat pump auxiliary heat pump system, including a separate auxiliary heat pump and solar radiation heat as a heat pump heat pump. Now to introduce what are the types and characteristics of solar heat pump water heaters. Direct-fired solar water heaters, solar water heaters In direct expansion systems, the refrigerant as a solar collector directly absorbs heat in the solar collector / evaporator and then releases heat of condensation to the heated objects through the heat pump cycle. With the exception of solar collectors / evaporators, the remaining components of the direct expansion system, such as compressors, condensers, and expansion valves, are exactly the same as conventional refrigeration / heat pump systems and therefore have a great potential for miniaturization and commercialization. Because the solar collector and the heat pump evaporator are both structurally and functionally integrated, the solar collector temperature always corresponds to the evaporation temperature of the refrigerant, that is, the collector temperature can be in a lower temperature range . This structure has the advantage of heat collection efficiency is very high, even with cheap bare-board collector can also get better heat collection performance, so the heat collection costs are very low. Non-direct-expansion solar heat pump water heaters In non-direct-expansion systems, solar heat collectors usually use fluids such as water, air or antifreeze solution to absorb heat in the solar collector and then transfer the heat directly to the heated object Or as a heat pump evaporator heat pump cycle after heating and heating objects. According to different connection forms of solar heat collection cycle and heat pump cycle, non-direct expansion solar assisted heat pump can be divided into three basic forms: tandem type, parallel type and dual heat source type. Series refers to the solar collector cycle and the heat pump cycle through the evaporator to be connected in series, the evaporator heat all from the heat cycle to absorb the heat; parallel refers to the solar collector cycle and heat pump cycle independent of each other, which only as the former can not Auxiliary heat source to meet heating demand. Further Reading: pump valve pipe fittings Exhibition 2016 Exhibition of Information Industry, Internet (Xiamen) Technology Co., Ltd. Author: Asian pumps Network Editor: Yao Xiaoxia (QQ / micro letter:) http://beng.liuti.cn/ (Hotline :)