Explanation Protection for Air Cooled Precision Chiller

The places where need air-cooled precision chiller indicate they have high demanding for operating accuracy. Therefore, the protection settings have to work out. Then, which kind of protection for air-cooled precision chiller should be done?

Discharging temperature protector should be installed on the air-cooled precision chiller in order to protect the compressor when it works with negative high stressing or without enough refrigerants. The temperature detected in the position of 10cm between compressor and exhaust pipe should range within 130±5℃for stopping the compressor.

Low tension switch is set for the safe of air-cooled precision chiller when it operates with not enough compressor refrigerant. When it reaches 0.03mpa, the compressor stops working. Once the compressor runs lacking refrigerating fluid, the temperature of parts of compressor and electrical machinery will rise instantly, so at that time, low tension switch can play a role in protecting them which inner thermostat and exhaust gas temperature protector can not function.

Electromagnetic switch operates on the basis of controlling air cooled precision chiller's cold compressor. When installing shutter which is for engine cutout, it ought to keep upright; if mistakes happen, spring pressure of joint will change, giving rise to make noises and phase-deficient operation. As for the compressor carried with an inner protector for cutting off power directly, it can be free from any loading protector.

High-voltage switch can stop the compressor when the high pressure raises abnormally. The operating pressure is under 3.0mpa.

Inner temperature controller must be installed inside the compressor in order to prevent it from moving at high speed which causes overcurrent produced by high load operation, poor electromagnetic switch and journal sticking or faults including motor burnout owing to motor temperature, which is mounted at the neutral point of three machines. When an error occurs, electrical machine will remain normal by cutting the three-phase machine at the same time.

The structures of the air-cooled precision chiller's anti-phase protector scroll compressor and piston compressor are different. The former isn't able to reverse because the three-phase supply of air-cooled precision chiller will lead to the changeover of compressor. Thus, anti-phase protector should be set for prohibiting the refrigeration compressor from reversal, with which the compressor can run smoothly when there is positive phase; otherwise, it stays motionless. When anti-phase happens, to exchange two lines of the power source can turn into a positive one.

The air-cooled precision chiller of Guanya Refrigeration Technology Co., Ltd in Wuxi sets up multiple failure alarms: over temperature alarm, sensor alarm, high pressure alarm and overheating alarm, avoiding some faults effectively and in time.

The Reasons of Frosting on Ultra low Temperature Recirculating Chillers

Frosting will appear when many users take advantage of ultra low temperature recirculating chillers, while some are not. It is confusing and whether it is relevant to refrigeration.

First of all, why does ultra low temperature recirculating chillers frost? To sort it out, we can turn our eyes on the reasons of direct-cooling ultra low temperature recirculating chillers. The frost is a white crystal of vapour which will congeal on the surface of ultra low temperature objects.

The air will frost on the surface of the inner wall inside ultra low temperature recirculating chillers, which is the root cause. It will affect the heat transfer efficiency, resulting in the decline of refrigerating capacity, so the users should remove it manually.

We understand why the ultra low temperature recirculating chillers will frost on one hand, and for the other hand the air-cooled one is frostless. Are their reasons against each other? The principle of that is the air-cooled ultra low temperature recirculating chillers applies air to refrigerate. When high temperature air flows through the inner evaporator, both of them will change the heat directly because they are in opposite conditions so that the temperature of air will lower.

Meanwhile, cool air is blown in the ultra low temperature recirculating chillers, which is exactly what air-cooled one uses for cycling constantly to reduce its own temperature. However, vapor always exists in the air, so it becomes solid when it freezes, which shows that whenever heat transfer happens, frosting will be in the ultra low temperature recirculating chillers.

In fact, air-cooled ultra low temperature recirculating chillers is carried with frost, but only on the surface of the evaporator. When opening the door, we can not see it because the frost is inside. Thus, we call it as frostless on the whole.

Therefore, we make it clear why ultra low temperature recirculating chillers is out of frosting.

The Noise Analysis of Precision Chiller

Generally speaking, even the most sophisticated refrigerating equipment will also have some trouble when used for a long time. If the noises present in the precision chiller after prolonged use, I am sure that it appears some faults. So let's go deeper to see where these noises are from.

The noise of compressor

The compressor is in the core position of the inner structure of the precision chiller. In general, compressors include screw and stroll, you can pick up one as what you need. Once the compressor has some noise, the first thing you should do is to check out if the expansive valve is open excessively; if so, you ought to adjust it. Next, you should see if the freezing medium is overmuch; if so, you had better remove the needless refrigerators.

The noise of water pump

It is attributable to the water quality mainly if the water pump has some noises. I suggest that water treatment should proceed according to the requirement of the chillers.  

The accessories lack lubricant

The configuration of most of chillers is made of metal. Once the accessories are short of lubricant, the frictions can not be avoided, making some noises. Besides, you have to keep maintenance in daily life to reduce the rate of faults.

Oil starvation because of overload

You can find out whether the compressor is fuel elan when there are some noises. If it is, you can refuel it. To check if the compressor is overloaded will help you solve it in time.

Through the introduction of precision chillers, you must have a better understanding. If you are eager to further study, you can follow Guanya Refigeration Technology Co., Ltd.

How to Debug the Expansion Valve of Low Temperature Freezer?

The effective operation of low temperature freezer is relevant to the needed refrigerating effect. It is crucial to correct expansion valve if better cooling effect is wanted. So, how to debug the expansion valve of low temperature freezer?

During the operation of low temperature freezer, the smaller the opening is, the less the volume of fluid transmission and pressure are,and vice versa. Based on the thermodynamic property of refrigerating fluid, the corresponding temperature varies as the pressure differs. The pressure raises, so does the temperature.

Therefore, if the pressure of the expansion valve of low temperature freezer is too small, the evaporating pressure and temperature will be too low. However, the speed of evaporation, volumetric refrigeration capacities and cooling efficiency will reduce because the flow of evaporator decreases and the pressure declines.

Conversely, the outlet of the expansion valve of low temperature freezer has excess process pressure, the evaporating pressure and temperature will also be too high. And the flow and pressure entering the evaporator of low temperature freezer rise. The compressor functions abnormally because damp gas (even the liquid) caused by excessive liquid evaporation is absorbed by compressor to produce wet stroke, bring about a series of severe conditions and even the damage o compressor. So with that being said, the opening level of the expansion valve of low temperature freezer should be regulated according to the temperature of the low temperature freezer of the day, which means as per related pressure.

The inlet pressure of low temperature freezer goes with higher evaporating pressure generally due to the pressure loss of air suction pipe and degree of superheat ( it depends on the length of pipeline and thermal barrier effect). At that time, the regulate pressure should be similar to the evaporation pressure ( the latter one will be a little higher). The regulation of the expansion valve of low temperature freezer should proceed carefully and patiently. The modulating pressure must pass the ebullition of heat exchange produced by the evaporator and the temperature of low temperature freezer before going into the intake cavity of compressor through pipelines to reflect on the pressure gauge, which takes time.

Guanya Refrigeration Technology Co., Ltd in Wuxi reminds that it takes 10 to 15 minutes every time for the regulation of the expansion valve of low temperature freezer to stabilize the pressure on the inlet pressure gauge. It should act with undue haste. The inlet pressure is a major parameter-basis for the compressor of low temperature freezer. The technical characteristics of the expansion valve of low temperature freezer influence the normal regulating operation straightway.

It is essential to tackle in time when faults like blocking and ice block happen in case that they affect the use of low temperature freezer. The low temperature freezer price from LNEYA is really reasonable. Come and contact us.

Daily Maintenance of Low Temperature Freezer

Low temperature freezer, which is also called industrial refrigerator, is mainly used for industrial cold treatment, the increase of wear-resisting property and friction of metals. Guanya Refrigeration Technology Co., Ltd in Wuxi is a leading role in the national Low Temperature Freezer Ranking List and its professionals make a conclusion about the related routine maintenance particularly. Also low temperature freezer price is the keypoint of its quality.

Every specialist is responsible for corresponding low temperature freezer in the industry, thus other personnel without the permission of operators will be not allowed to use the equipment. To ensure the time of duration for opening of low temperature freezer should not be over 5 minutes with more than 20-minute interval. It is suggest from Low Temperature Freezer Ranking List that a detailed record ought to be done about the opening and closing time as well as the exceptional situations. When abnormal conditions occur, equipment control sections should be reported with a record.

Low temperature freezer applies the artificial method for frost removal, and automatic cycle of freezing and thawing will degrade the biological samples. If the low temperature freezer of LNEYA in Wuxi of Low-Temperature Ranking Freezer List has worked for 24 months, it has to be killing frost once. Of course, the manager can decide whether the time should be earlier or not according to the physical truth, but every 24-month interval should be carried on at most. Before defrosting, enough dry ice ought to be prepared well. When the samples are taken out from freezer, they should be put into dry ice quickly and covered with a certain number of them. Then, a next step is to transfer them to the storage device in reserve.

Low Temperature Freezer Ranking List advises that the power supply of freezer should be turned off when all samples are settled down and open the door of freezer so as to melt the frosted ice gradually. It is banned to use metal tools to remove rime ice of in wall of freezer forcibly in case of the damage to the box. After the rime ice melt completely, to use a clean duster cloth to dry the residual moisture content inside, then to open the door for 1 to 2 hours, finally to close the door and power up.

After the completion of low temperature freezer and before the restocking of samples, the low temperature freezer should operate above 16 hours in order that the in-wall temperature of box can be down to target temperature and reach equilibrium states. After the defrosting finishes, the samples will be transferred back to the equipment based on the original storage location.

Numerous brands are in the Low Temperature Freezer Ranking List, which is important for buyers to be cautious. Generally, all of them can lengthen the service life of wear-out part directly, generally apply for thermal contraction of copper bush and bearing , and extensively use for sophisticated mechanized equipment .

The Introductions of the Ultra Low Temperature Recirculating Chillers

The performances of ultra low temperature recirculating chillers are different because of their different compressors. Compared with piston compressor, the structure of screw-type compressor tends to be more precise, so when users need to select ultra low temperature recirculating chillers, they should understand the cooling operation.

When working, the ultra low temperature recirculating chillers’ screw-type compressor will spray lubricant into the working chamber, functioning as lubrication, cooling, sealing, soundproofing, lubricating for main bearing , thrust bearing and shaft seal, a push for pressure oil of oil piston and balance piston. These oils will mix with high pressure gas to be expelled from compressor.  

Suction strainer: the ultra low temperature recirculating chillers’ suction strainer is comprised of shell and metal filter mesh. The shell is installed with suction thermometer, pressure gauge and priming valve, among which priming valve is the oil position for unit operation that needs paying attention to.

Oil cooler: the lubricating oil isolated from the engine oil of ultra low temperature recirculating chiller leads to the temperature rising ( close to exhaust heat temperature) for it absorbs friction heat and the heat of air. The oil temperature is so high that viscosity decreases, weakening the sealing function, increasing internal leakage and lowering the efficiency of compressor. Thus, it is necessary for lubricant to go through cooling for purpose of reuse. The oil cooler of ultra low temperature recirculating chiller is definitely for cooing the oil.

Coarse oil filter: in order to ensure the working of oil pump of ultra low temperature recirculating chillers, the lubricating oil should be purified through coarse oil filter before entering the oil pump.The later cleanliness of coarse oil filter should be checked for the first operation of the machines. And overhauling the filter mesh regularly should be on the basis of the system cleanliness. Gas or kerosene can be applied to clean the filter mesh, and get them clean with dry air for continuous use.

Oil- pressure adjusting valve: the ultra low temperature recirculating chillers’ oil-pressure adjusting valve is to regulate the injection pressure of compressor. If the ingoing oil pressure of compressor is excessive, the fuel-injection quantity will be overmuch, not only influencing the air removal of compressor but wasting work of it as well as increasing the possibility of shaft tunnel oil leakage of ultra low temperature recirculating chillers. Otherwise, the fuel-injection quantity will be too small, degrading the function of lubricant.

Oil separator: the oil separator of ultra low temperature recirculating chillers’ compressor unit is divided into vertical type and horizontal type. The interior of oil contains three chambers. The one next to the staving of compressor is for keeping the oil level, whose external shell is placed two sight glasses at top and bottom to observe the height of oil (automatic unit has oil level controller). That near the staving of electrical machinery is for installing the highly efficient filter element to separate the quadric oil, whose outboard also has a sight glass so as to decide whether to return oil or not based on the oil level.

The ultra low temperature recirculating chillers'screw-type compressor is quite complicated, thus it is good to have some relevant knowledge of its cooling and accessories when buying.

Leakage Detection Tips of Low Temperature Freezer

Pressure leaking detection

It is an effective way to check and find out the leakage point. The leakage detecting pressure of refrigerating system of freezer is relevant to the type of refrigerating fluid and cooling and the location of tube. The leakage detecting pressure of high-pressure system is 1.25 times greater than designing condensing pressure, while that of the low-pressure system is near 1.2 times higher than saturation pressure in condition of the temperature in summer. With it, refrigerating plant can stop from leakage no matter it is working or parking. Some cooling system should be detected according to the provisions of the pressure if there is a predefined acceptance or leakage detection standard. Obviously, the leakage detecting pressure can not be raised casually, otherwise it is likely to destroy the equipment, resulting in an accident.

Bubble test

It is a widely used detecting method at present , especially for those medium and large freezer systems that take advantage of it to search for the leak point. Generally, bubble test is comprised of soap or soap powder. The solution of soapy water should not be too ropy; if not, the viscosity will be too big to flow, worsening the sensitiveness of the test. But as an editor of Whose Low Temperature Freezer Is Best，i would like to tell you that the modulation not ought to be too dilute, or else the fluidity will be too large to be adhere to the surface of the equipment, being hard to form the bubbles. The soapy water can be applied the leaky point with hairbrush directly to observe whether this position is blistering. When it comes to the positions that are difficult to observe straightway, mirror reflection and flashlight can be used. After the test, the soapy water should be dried up in case of corrosion.

LNEYA have more freezers for sale and low temperature freezer price is really affordable.