شیر انبساط الکترونیکی
امتیاز شیر انبساط سوپرهیت الکترونیکی کاملا واضح میباشد. حتی در حداکثر بار، اواپراتور بهتر با مبرد پر میشود. (حداکثر فشار کارکرد اواپراتور) که بدین معنی است که میتوان بارهای کم را نیز به خوبی تنظیم کرد. و مقدار دقیق مبرد تزریقی به اواپراتور را مشخص کرد.
این عمل بوسیله حس کردن مقدار دقیق سوپرهیت در اواپراتور انجام میگیرد. و بدین معنی است که یک حس کننده فشار (p در شکل۱) و سنسورهای (s2 در شکل۱) این اطلاعات را به کنترل کننده میفرستند. (EKC315A) و این امر در سریع ترین زمان ممکن اتفاق میافتد.
Electronic Expansion Valve
Today electronic expansion valves have high consumption. They have many advantages for example there is no need to use a special valve for every type of refrigerant. You can use these valves for the gases R410A, R407C, R404A, R507, 134, R22 and R123ZE. In some models it is usable for Co2 gas that is R744. These valves have a simple structure and function. They consist of a drive that is installed in the panel which we describe it in the next video. In this film we are going to examine their structure.
The valve has a step motor which connects to the drive through this cable and when it’s commanded it will rotate this screw to right and left that causes the valve close or open. But how it happens?
The part you see will be mounted on this screw; this secondary cylinder will be placed here like this. The piston goes into this cylinder as well and can open or close the gas route or reduce or increase it according to our settings. Piston sits in the expansion valve through this black part which is neoprene and the expansion valve is sealed completely so you don’t need to mount a solenoid valve. So this is how piston is placed in expansion valve.
Hence the entrance gas is set by this step motor which is controlled by step motor itself. How? The drive commands, step motor rotates the screw, the screw rotates the plastic piece and plastic piece moves the piston in secondary cylinder up and down. Accordingly you can balance the entrance refrigerant to evaporator more accurate than in thermostatic expansion valve and also you can set the maximum ODP more precisely which is not possible in thermostatic expansion valves.
This valve is made for 45/5 bar function by which you can have more efficiency. Even some manufacturers announce that these valves can increase efficiency by 15%.
Not mounting solenoid valve causes you have more subcool gas in expansion valve entrance so subcool temperature won’t increase. The result will be more efficiency which was not possible in thermostatic valves. In other words because you can precisely adjust the entrance superheat to the compressor the efficiency will increase.
As we described in previous topics entrance superheat temperature to the compressor is one the most important parameters in not having failure in compressors, not returning liquid to compressor, preventing the compressor getting hot and increasing the efficiency of system and evaporator.
In this part there is a sight glass that shows the moisture rate.
In next film we will explain the way of mounting and setting up the expansion valve completely.