[Mobile Equipment Technology Edition] Daily Question 20170907 Refrigeration Design
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This post was last edited by YORK Industrial Refrigeration on 2017-9-9 14:48. From now on, in order to strengthen exchanges with friends, we have launched a [Daily Question] activity in the Animal Equipment Technology Edition. We hope that everyone will actively participate and make progress and improvement together! ! ! award: Actively participate in 3 fortunes and answer 10-15 fortunes intact. This question is valid for two days and will not be graded for more than two days. question: In refrigeration systems, brine units, and shell-and-tube water-cooled condensers, why can’t water travel through the shell? Why can the brine of the evaporator go through both the tube side and the shell side? What is the essential reason? Answer: Because the cooling water inlet temperature is between 26 and 30 degrees, the outlet water temperature is determined by the saturation temperature and heat exchange effect. Due to the influence of temperature, there is a lot of scaling and needs to be cleaned in time. I won’t say anything more next. . . . Understand it yourself. ================================ Event promotion: Petrochemical Zone---"Brain-expanding" activity on new energy-saving ideas (the second phase of the activity is in progress) http://bbs.hcbbs.com/thread-1666758-1-1.html (Source: Haichuan Chemical Forum Network) "My Technical Transformation of Coal Chemical Industry in 2017"” http://bbs.hcbbs.com/thread-1786290-1-1.html (Source: Haichuan Chemical Forum Network)
1. Consider the characteristics of the refrigerant itself (changes in the condenser and evaporator)； 2. Maximize efficiency.
In the refrigeration system, brine unit, and shell-and-tube water-cooled condenser, water flows through the tube, which can increase the flow rate, reduce scale accumulation, and make it easy to clean the scale. The brine of the evaporator can go through either the tube side or the shell side, because the brine has no impurities.
There are many impurities in the water. If the shell is removed, it will be difficult to clean after scaling. When water travels through the pipe, the pressure of the water changes less, which can increase the flow rate and improve the heat transfer effect. Compared with water, brine has much fewer impurities and can remain relatively clean in the shell side.
Because the average heat transfer coefficient between the cooling water and the tube bundle is generally higher than the average heat transfer coefficient for refrigerant vapor condensation, condensation requires a larger heat exchange surface.； In addition, in order to control the pressure of high-temperature and high-pressure refrigerant vapor within a certain range, a large space is also required. So the water goes through the pipes.
Hot materials can dissipate heat into the air during the shelling process, making the cooling effect better.
The quality of the circulating water is relatively dirty, and the shell removal process is easily blocked and difficult to clean.
The quality of the circulating water is relatively dirty, and the shell removal process is easily blocked and difficult to clean.