CBFI AT60 60 Tons Per Day Ammonia Refrigerant Tube Ice Machine

Low-temperature chillers generally use imported scroll compressors. Therefore, many customers also call them scroll chillers. During the operation of the chiller, various problems will often cause the compressor to burn out and liquid strike.The liquid hammer of the compressor of the cryogenic chiller can cause damage to the scroll. The liquid hammer failure is generally manifested as the obvious metal impact sound inside the compressor. This is the metal fragments after the scroll is crushed. The sound of impact with the compressor housing.There are three main situations for liquid shock: one is that a large amount of refrigerant liquid enters the compressor at the moment of startup; the other is that the flow of the evaporator is insufficient (the saving load is reduced), and the compressor has liquid back phenomenon; the third is that the unit heat pump is running except The frost is not good, a large amount of liquid refrigerant enters the compressor without evaporating, or the liquid in the evaporator enters the compressor when the four-way valve is switched.　　So, how do we solve the problem of liquid strike or liquid return?　　 1. The piping design should prevent liquid refrigerant from entering the compressor when starting up, especially in refrigeration systems with a relatively large charge. Adding a gas-liquid separator at the compressor suction port is an effective way to solve this problem, especially in heat pump units that use reverse cycle hot gas defrosting.　　 2. Before starting the machine, preheating the oil chamber of the chiller compressor for a long time can effectively avoid a large amount of refrigerant from accumulating in the lubricating oil. It also has a certain effect on preventing liquid shock.　　3. Water system flow protection is indispensable, so that when the water flow is not enough, it can protect the compressor. If the famous unit has liquid back phenomenon or freezes the evaporator in severe cases.　　What is the reason for the overheating of the compressor of the chiller equipment? We analyze it from three aspects:　　 First, the compressor is overloaded and runs over current. The possible factors are: the cooling water temperature is too high, the refrigerant is overcharged, or there is non-condensed gas such as air in the refrigeration system, which causes the compressor to have a heavy load, which manifests as an overcurrent and is accompanied by high pressure.　　Second, the electrical fault caused the overcurrent operation of the compressor of the low-temperature refrigerator. If the three-phase power supply voltage is too low or the three-phase is unbalanced, the current or a certain phase current is too large; the communication contactor is damaged, the contact is ablated, and the contact current is too large or the current is too large due to lack of phase.　　 Third, the overheating maintenance module SSM of the low-temperature refrigerator is damp or damaged, the central relay is damaged, and the contacts are bad. The performance is overheating when starting up, and the compressor cannot be started. If the unit electronic board is faulty or communication fault, it may also falsely report the overheat fault.

There are 13 common failures of ice machine compressors. Today I will introduce 3 reasons for you:       1、The shaft seal is leaking seriously　　Overhaul ideas　　 （1）. Check whether the shaft seal is poorly matched, causing serious oil leakage in the shaft seal.　　 The shaft seal should be assembled correctly.　　（2）. Check whether the friction surface between the moving ring and the fixed ring has been roughened.　　 If the fuzz is severe, the sealing surface should be carefully ground and reassembled.　　（3）. If the rubber sealing garden is aging or the tightness is not set properly, oil will leak.　　In this regard, a new rubber garden should be replaced and the appropriate tightness should be adjusted.　　（4）. Check whether it is due to the weakening of the elastic force of the shaft seal spring that causes the shaft seal to leak oil.　　 The original spring should be removed and replaced with a new one of the same size.　　（5）. Check whether the sealing performance between the back of the fixing ring and the shaft seal gland has deteriorated.　　For this, remove the fixing ring, clean the back ring and reassemble it.　　 （6）. If the crankcase pressure is too high, adjustments should be made.　　 But before stopping, lower the pressure of the crankcase and check if the exhaust valve is leaking.　　 2、The shaft seal oil temperature is too high　　Overhaul ideas　　 （1）. Check whether the lubricating oil is insufficient or the oil pipeline is blocked.　　If the oil is insufficient, add lubricating oil in an appropriate amount; if the pipeline is blocked, the oil pipeline should be cleared.　　 （2）. Check whether the lubricating oil is dirty or has deteriorated.　　 For this, the filter should be cleaned and replaced with new oil.　　 （3）. Check whether the friction surface of the moving ring and the fixed ring is too tight.　　 The elastic strength of the spring should be adjusted appropriately.　　 （4）. The packing gland is too tight.　　 The gland nuts should be adjusted evenly to avoid being too tight, resulting in too high shaft seal oil temperature.　　 （5）. Check whether the main bearing assembly clearance is too small.　　 For this, the gap should be adjusted appropriately.     3、The pressure in the crankcase of the ice machine compressor increases　　Overhaul ideas　　 （1）. The piston ring is not tightly sealed.　　The sealing ring of the new piston should be replaced if the seal is not tight, which leads to the high pressure to the low pressure.　　（2）. The exhaust valve is not closed tightly, causing the pressure in the crankcase to rise.　　 The air tightness of the exhaust valve seat should be checked. If the seal is not tight, a new valve should be replaced in time.　　（3）. The airtightness between the cylinder liner and the machine base has deteriorated.　　 The cylinder liner should be removed, the joint should be cleaned and sealed, and then reassembled.　　（4）. Too much ammonia enters into the crankcase and the pressure rises after evaporation.　　 As long as the excessive ammonia in the crankcase is evacuated.

       The air cooler is a commonly used evaporator in the refrigeration system of commercial ice machine, and its selection directly affects the efficiency of the refrigeration system. As we all know, the air cooler will use different fin spacings according to the required ambient temperature. 　　      Our common commercial ice machine air coolers have fin pitches of 4mm, 4.5mm, 6~8mm, 10mm, 12mm, as well as front and back variable blade pitches. The fin spacing is small, suitable for high temperature environments; the lower the cold storage temperature, the greater the fin spacing required. If the selection is unreasonable, the fins will quickly frost, which will quickly block the air passage, and it will be difficult for the cold storage to cool down, and the efficiency of the compressor will not be used, which will increase the power consumption of the refrigeration system. According to engineering experience, generally 0℃~20℃ environment, such as workshop air-conditioning, cool storage, cold storage hall, fresh-keeping storage, air conditioning storage, ripening storage, etc., choose air coolers with a spacing of 4mm or 4.5mm; ~-25℃ environment, such as low-temperature freezing and cold storage, low-temperature logistics warehouse, choose air coolers with a sheet spacing of 6mm~8mm; for quick freezing warehouses at -25℃~-35℃, generally choose air coolers with sheet spacing of 10mm and 12mm. If the humidity of the quick-frozen cargo is high, a variable fin pitch air cooler will be selected, and the fin pitch on the inlet side can reach 16mm.        However, there are some occasions where the air cooler fin spacing cannot be selected solely based on temperature, such as rapid pre-cooling of meat and vegetables, and acid discharge. Although the temperature of the cold room is generally set above 0°C, because the incoming temperature is high and the temperature is lowered With high speed and high humidity, if you choose a cooler with a sheet spacing of 4mm or 4.5mm, it is not suitable. You must use a cooler with a sheet spacing of 8mm or even 10mm. There are also cold storages similar to the storage of garlic, apples and other fruits and vegetables. The suitable storage temperature is generally -2°C. For this kind of fresh-keeping or air-conditioned storage with a storage temperature below 0°C, air coolers with a spacing of not less than 8mm are also required. , In order to avoid the rapid frosting and block the air duct and increase the power consumption. The influence of frost on the refrigeration system:　　      The surface temperature of the evaporator during the normal operation of the cold storage refrigeration system is much lower than the dew point temperature of the air, and the moisture in the air will precipitate and condense on the pipe wall. If the pipe wall temperature is lower than 0°, water dew will condense into frost. Frosting is also the result of the normal operation of the refrigeration system, so a small amount of frosting is allowed on the surface of the evaporator. 　　Because the thermal conductivity of frost is too small, it is one hundredth or even several hundredths of metal, so the frost layer forms a larger thermal resistance. Especially when the frost layer is thick, it is like heat preservation, so that the cold in the evaporator is not easily dissipated, which affects the refrigeration effect of the evaporator, and ultimately makes the cold storage unable to reach the required temperature. At the same time, the evaporation of the refrigerant in the evaporator of the commercial ice machine should also be weakened. The incompletely evaporated refrigerant may be sucked by the compressor and cause a liquid shock accident. Therefore, we must try to remove the frost layer, otherwise the frost layer will become thicker and the cooling effect will become worse and worse.  

        Refrigeration compressor lubricating oil is usually mixed with a special additive and base oil to provide the necessary lubrication performance, while also being compatible with the refrigerant. Any incompatibility between base oil and refrigerant can lead to catastrophic results for the equipment. 　　        Most ice machine compressor lubricants are synthetic. This allows them to have a longer service life and face the severe tests of the system better than mineral base oils. Most home air conditioners now use a mixed refrigerant called R-410A. The application of polyol ester (POE) base oil is beneficial to the lubrication system, and this oil can also be separated from the refrigerant. Although compatibility between refrigerants and lubricants may be the most pressing lubrication problem, there are many other aspects. For example, water pollution is harmful to many synthetic base oils that are unstable in hydrolysis. Moisture reacts with base oil to form acid, which changes viscosity and impairs lubricity. This may cause premature compressor failure and improper system cooling. 　　     Lubricant problems are common in any system. One way to avoid problems with the gas being compressed is to simply remove the lubricant from the reaction formula. This happens often when "dry" compressors are used more and more widely. "Dry" refers to the lack of oil in the compression chamber. If the lubricant is not in the compression chamber, it will not easily cause problems with the refrigerant. However, in a humid or water compressor, the oil is present in the compression chamber and is intimately mixed with the refrigerant. In these systems, the compatibility of the lubricant and the refrigerant is the most important. 　　        Many large ice machine compressors use a forced lubrication system, which has an oil reservoir, pipes and pumps. The pump pushes the oil through the pipeline into the compressor to achieve lubrication and cooling, and then returns to the oil reservoir. The operation of these systems enables you to filter, cool, and separate gas and water from oil. 　　      Smaller compressors are usually static lubrication systems. In this lubrication system, the compressor saves oil and the system is completely sealed. As long as it is cleaned and sealed before use, this type of system is less likely to have lubricant failure. In most cases, these systems will operate for many years without the need for oil changes. Lubricating oil is present in the compressor for lubrication, but some oil will flow out through the refrigerant line. In some cases, it is necessary to use an oil sump or knock out the method to prevent the oil from blocking the pipeline and reduce the cooling capacity of the system.