The refrigeration system of a refrigerated dryer belongs to compression refrigeration, consisting of four basic components: a refrigeration compressor, a condenser, a heat exchanger, and an expansion valve. They are sequentially connected by pipelines to form a closed system. The refrigerant continuously circulates and flows in the system, undergoes state changes, and exchanges heat with compressed air and cooling media. The refrigeration compressor sucks the low-pressure (low-temperature) refrigerant from the heat exchanger into the compressor cylinder, and the refrigerant vapor is compressed, causing both pressure and temperature to rise simultaneously; High pressure and high temperature refrigerant vapor is compressed into the condenser, where the higher temperature refrigerant vapor exchanges heat with cooler water or air. The heat of the refrigerant is carried away by water or air and condensed, resulting in the refrigerant vapor becoming a liquid. This part of the liquid is then transported to the expansion valve, which restrains it into a low-temperature and low-pressure liquid and enters the heat exchanger; The low-temperature and low-pressure refrigerant in the heat exchanger absorbs the heat from the high-temperature and high-pressure compressed air. The compressed air is forced to lower its temperature while maintaining a constant pressure, resulting in a large amount of supersaturated water vapor. And the refrigerant vapor in the heat exchanger is sucked away by the compressor, so the refrigerant goes through four processes in the system: compression, condensation, throttling, and evaporation, thus completing a cycle.

Energy conservation and environmental protection are the design concepts that the company's R&D personnel have always followed and implemented in the design process, while organically combining production costs and product performance. The plate type refrigerated dryer currently being mass-produced by the company is the crystallization of the company's design concept, with the main heat exchanger components using a perfect combination of stainless steel plate heat exchangers and cyclone separation water removal devices.

1： Why does the plate type refrigerated dryer save energy

The stainless steel plate heat exchanger used in the plate type refrigerated dryer is composed of many metal plates that are connected in a staggered manner. The plates are welded and sealed to form cold and hot fluid channels on both sides of the heat transfer plate. During the flow process, heat exchange is carried out through the plate walls. The two fluids exhibit a countercurrent heat transfer pattern in the flow channel, and the surface of the plate creates various shapes such as waviness and herringbone, which is conducive to breaking the laminar film layer of the fluid and generating vortices at low speeds, forming strong turbulent flow to enhance heat transfer. This greatly improves the heat transfer efficiency of the precooled regenerator, reduces the temperature difference between the inlet and outlet, and allows compressed air to enter the evaporator at a lower temperature. It is obvious that, When reaching the same pressure dew point, the refrigeration capacity of the refrigerated dryer is lower than that of a conventional shell and tube heat exchanger, which means it needs to consume lower refrigerant compressor power. If shell and tube heat exchangers want to achieve the same energy-saving effect, they need to increase the heat exchange area by 5-10 times. The cost of copper tubes and the external dimensions of the equipment are unimaginable.

2： Other advantages of stainless steel plate heat exchangers:

Compact structure

Using thin plates, high heat transfer coefficient, and low liquid retention

Low fouling coefficient

High turbulence reduces the fouling coefficient

Pollution-free

The internal structure is made of stainless steel 316/304L, which is not easy to rust and does not pollute the gas

Lightweight

Only equivalent to 20%~30% of shell and tube heat exchangers

Lower pressure drop

Less than 0.018MPa

3： Comparison of energy consumption between plate type refrigerated dryer and ordinary shell and tube type refrigerated dryer

For example, when a HX-200NF (23m3/min) refrigerated dryer uses a traditional tube fin heat exchanger, it requires a refrigerant compressor power of 5HP, while the HX-200NPF using a plate heat exchanger requires a refrigerant compressor power of only 4HP. Therefore, if the refrigerated dryer works for 12 hours a day and the electricity cost is 1.0 yuan/kWh, the electricity cost savings over the year are calculated as follows:

12 x 1HP x 0.735kw x 1.0 yuan/kWh x 365 days=3219.3 yuan/year

If you work 24 hours and use multiple machines at the same time, you will save more electricity bills!

4： Other forms of energy conservation

Generally speaking, the design of refrigerated dryers is based on extremely harsh working conditions at full load. However, many users often have large fluctuations in their gas consumption. Sometimes, when the gas consumption is small or the exhaust temperature of the air compressor is low, the phenomenon of "big horse pulling small car" may occur, which can easily cause severe frosting of the heat exchanger and "ice blockage", and may carry liquid into the compressor, diluting the lubricating oil of the compressor, The inability of compressor components to receive normal lubrication greatly reduces the service life of refrigerant compressors, and invisibly increases energy consumption.

In response to this phenomenon, our company has launched a dual head modular refrigerated dryer.

The entire machine adopts both automatic and manual modes. Automatic mode: main start and stop switches. After pressing the main start switch, the 1 # compressor runs, the temperature controller is powered on, and operates within the range of 3-10 ℃ according to the set temperature. When the outlet temperature (pressure dew point) of the evaporator is above 10 ℃, the 2 # compressor will automatically start. When the temperature is below 3 ℃, the 2 # compressor will automatically shut down.

This mode is easy to operate, safe and reliable, and has a significant energy-saving effect in situations with significant load changes. In terms of cost-effectiveness and reliability, it is significantly superior to variable frequency refrigerated dryers and similar products.