In the modern manufacturing world, laser cutting machines have become an indispensable metal processing tool for a wide range of industries, from metalworking to electronics manufacturing. Chiller as an important part of the fiber laser cutting machine, is to ensure that the laser cutting machine to play the best performance of the key components. Some customers in the use of fiber laser cutting machine, will encounter unstable operation of equipment, cutting accuracy decline and other problems, and these problems are largely closely related to the laser cutting machine cooling system, the core of which is the laser cutting machine chiller. As a key component to ensure the stable operation of the laser cutting machine, the performance of the chiller directly affects the production efficiency and product quality. This article will discuss the significance of the laser cutting machine chiller, working principle, common failures and their corresponding solutions to help users better understand and maintain this important equipment to ensure that the laser cutting work can be carried out efficiently and stably, to enhance the overall efficiency of industrial production.
Ⅰ. The Importance of Water Chillers for Laser Cutting Machines
1. Ensuring Stable Laser Output
During the operation of laser cutting machines, a significant quantity of heat is generated. When the heat accumulates excessively, it triggers the expansion of laser components. This expansion, in turn, disrupts the stability of the laser beam output, leading to fluctuations in its intensity and direction.Here, a water chiller steps in as a critical element. By continuously circulating coolant, it effectively absorbs the surplus heat, maintaining a constant temperature environment around the laser source. This consistent temperature control is the linchpin for ensuring the stability and accuracy of the laser beam. In high – precision cutting applications, such as the manufacturing of micro – components in the electronics industry or the engraving of intricate patterns on delicate materials, even the minutest deviation in the laser beam can translate into defective products. Therefore, the stability provided by the water chiller is not just beneficial but essential for achieving top – notch cutting quality and minimizing production losses.
2. Prolonging Equipment Lifespa
Overheating is also one of the main reasons for premature failure of laser cutting machines. And by effectively dissipating heat, water chillers help prevent the deterioration of critical components such as laser diodes, optics and power supplies. With a water chiller, the operating temperatures of these components are kept within an optimal range, which reduces wear and tear and greatly extends the overall life of the laser cutting machine. This not only saves on the cost of frequent equipment replacement, but also increases the overall productivity of the manufacturing process.
3. Improving Cutting Efficiency
The water chiller can be fiber laser cutting machine for a long time continuous work. Laser cutting machine can maintain high cutting speed and power output when working at proper temperature. The chiller allows the machine to work continuously without any performance degradation due to heat buildup. This allows manufacturers to increase production capacity and more efficiently meet tight deadlines.
Ⅱ. Working Principle of Water Chillers for Laser Cutting Machines
Basic Refrigeration Cycle
Water chillers for laser cutting machines typically operate based on the vapor – compression refrigeration cycle. This cycle involves four main components: the compressor, condenser, expansion valve, and evaporator.
- Compressor: The compressor is the heart of the refrigeration system. It takes in low – pressure refrigerant vapor from the evaporator and compresses it to a high – pressure, high – temperature vapor. This compression process increases the energy of the refrigerant, preparing it for the next stage of the cycle.
- Condenser: The high – pressure, high – temperature refrigerant vapor enters the condenser, where it releases heat to the surrounding environment. As the refrigerant cools down, it condenses into a high – pressure liquid. The heat dissipated in the condenser is usually removed by air or water, depending on the type of condenser.
- Expansion Valve: The high – pressure liquid refrigerant then passes through the expansion valve. The expansion valve reduces the pressure of the refrigerant, causing it to expand and cool down rapidly. This results in a low – pressure, low – temperature liquid – vapor mixture.
- Evaporator: The low – pressure, low – temperature refrigerant mixture enters the evaporator, where it absorbs heat from the water that is circulating around the laser cutting machine. As the refrigerant absorbs heat, it evaporates back into a low – pressure vapor, and the cooled water is then returned to the laser cutting machine to absorb more heat.
Heat Exchange Process
The water chiller uses a heat exchanger to transfer heat from the water in the laser cutting machine to the refrigerant. There are two common types of heat exchangers used in water chillers: shell – and – tube heat exchangers and plate – type heat exchangers. In a shell – and – tube heat exchanger, the water flows through the tubes, and the refrigerant flows around the tubes. In a plate – type heat exchanger, the water and refrigerant flow between thin metal plates, which maximizes the surface area for heat transfer.
Ⅲ. Common Malfunctions and Solutions of Water Chillers for Laser Cutting Machines
1. Compressor Overload Alarm
Malfunction Phenomenon: The compressor overload warning light is on. Poor heat dissipation can cause the condensing temperature and corresponding condensing pressure of the condenser to be too high, which will cause the high – pressure part of the pressure controller to act, and the compressor will be overloaded and protected. Since the compressor shutdown will affect the normal use of customers.
Solutions: Place the water chiller in a well – ventilated and heat – dissipating location. When the compressor is overloaded and displayed on the water chiller control panel:
High – pressure Overload: If the overload display can be canceled through the pressure controller reset button, it can be determined as high – pressure overload. The reasons for high – pressure overload include the fan not rotating, the solenoid valve being stuck and unable to open, poor ventilation and heat dissipation of the equipment, and the condenser being dirty and blocked. The solution is to place the water chiller in a well – ventilated and heat – dissipating location, blow the dust on the condenser fins with an atmospheric pressure of about 1MPA, and then observe whether the high – pressure after the compressor works is lower than 2MPA. If the fan does not rotate or the solenoid valve is stuck, these are accessory problems and can be replaced.
Low – pressure Overload: Observe the pressure gauge. If the high – pressure and low – pressure are lower than 0.2MPA, it can be determined as low – pressure overload. In this case, there must be a refrigerant leakage in the equipment’s fluorine system. The solution is to pressurize the equipment to check for leakage points, repair the leaks after finding them, evacuate the system, add compressor oil, add refrigerant, and add refrigerant according to the weight marked on the nameplate. Professionals can also add refrigerant according to the pressure.
Current Overload: If the compressor overload display can be canceled through the thermal overload reset button, it can be determined as current overload. Current overload occurs when the compressor current exceeds the rated current and is overloaded and protected. Generally, only when the compressor is phase – deficient or the ambient temperature is too high will current overload occur. The solution is to improve the working environment, check the reasons for the compressor’s phase – deficiency. First, check whether the three – phase resistance of the compressor is normal (three – phase balance, and the resistance of about 5Ω is normal). If it is not normal, the compressor is broken. Then check whether there is poor contact in the compressor wire and whether there is a phase – deficiency in the AC contactor.
2. Abnormal Pressure Gauge
Malfunction Phenomenon: When the water chiller is operating normally, the high – pressure should not be greater than 2.0MPA. If it exceeds this pressure, it indicates that the condenser has poor heat dissipation. The low – pressure should not be less than 0.2MPA. If it is lower than this pressure, it indicates that there is a refrigerant leakage in the condenser or a dirty blockage in the throttling part.
Solutions: For high – pressure problems, clean the dust on the condenser fins with high – pressure gas. For equipment without a pressure gauge, regularly clean the condenser fins. For low – pressure problems, if there is a refrigerant leakage, it is necessary to find and repair the leakage points as described above. If it is a dirty blockage in the throttling part, clean or replace the relevant components.
3. Decreased Cooling Effect
Malfunction Phenomenon: If the water tank is not cleaned for a long time, the evaporator inside the water tank will generate microorganisms, resulting in poor heat exchange and affecting the cooling effect.
Solutions: Customers are requested to regularly clean the water tank and change the water frequently. Generally, replace the pure water once a month and clean the water tank (clean with detergent) at the same time to ensure that the water quality of the water chiller is clean.
4. Water Pressure Alarm
Malfunction Phenomenon: When the water pressure is around 0.3MPA, it is in a normal state. When it is abnormal, it will cause a flow alarm output.
Solutions: To avoid abnormal water flow in the water chiller, regularly check whether the filter element and the filter inside the water tank are dirty and blocked. If there is a blockage, replace the filter element and clean the water filter. If the external resistance is too large, the return water flow is small, or the alarm set value is too large, the flow switch can be adjusted to solve this problem. If there is air inside the pump, in the case of power – off, unscrew the exhaust screw until water overflows, and then tighten it.
5. Water Chiller Not Cooling
Malfunction Phenomenon: Observe whether there is a compressor overload display on the water chiller control panel.
Solutions:
Displaying Compressor Overload:
High – pressure Overload: As mentioned above, check and solve problems related to ventilation, condenser cleaning, and accessory failures.
Low – pressure Overload: Find and repair refrigerant leakage points, evacuate, add oil and refrigerant.
Current Overload: Check compressor phase – deficiency and improve the working environment.
Not Displaying Compressor Overload: Observe whether the compressor is working.
Compressor Working: Observe the working pressure. If the high – pressure and low – pressure are close to balance when the compressor is working, and the fan blows cold air or slightly hot air, it can be determined that the solenoid valve is stuck or the compressor is broken. If the high – pressure is normal and the low – pressure is low, it can be determined that the expansion valve is adjusted too small, dirty, blocked, broken, or the evaporator surface is dirty and the conversion efficiency is low.
Compressor Not Working: Check all the electrical components of the AC contactor that controls the compressor to see if the output is normal. For example, for a 7HP equipment compressor AC contactor, the normally open point of the intermediate relay 1 outputs to the delay, and the normally open point of the delay outputs to the compressor AC contactor, and the AC contactor outputs to the compressor. If any electrical component has an abnormal output, it can be determined that this electrical component is broken.
Automatic Reset after Displaying for a Few Seconds: This fault is generally caused by the expansion valve being adjusted too small or having a fault. Adjust the expansion valve to the maximum position (clockwise adjustment is to reduce, and counter – clockwise is to increase). Check if the fault is eliminated. Then observe the low – pressure operating pressure to see if it is normal. Sometimes the pressure will be too high, and if so, adjust the expansion valve to a smaller size. If adjusting the expansion valve has no effect, it means the expansion valve is broken and needs to be replaced.
5. Water Level Alarm
Malfunction Phenomenon: The water level alarm is an alarm mode generated when the water level in the water tank is insufficient.
Solutions: When a water level alarm occurs, first observe whether the water in the water tank exceeds the water level switch. If not, fill the water. If the water level exceeds the water level switch and still alarms, check whether the float of the water level is stuck and move it a few times. If it still alarms, it means the water level switch is broken or the controller is broken.
5. Temperature Alarm
Malfunction Phenomenon: An over – temperature alarm usually occurs when the current temperature is higher than the upper limit of the alarm value or lower than the lower limit of the alarm value.
Solutions: After the alarm occurs, first check whether the water temperature in the water tank is the same as the temperature displayed on the temperature controller. If not, the controller or the temperature – control probe is faulty and needs to be replaced. If they are the same, observe whether it is an over – high – temperature alarm or an over – low – temperature alarm. For an over – high – temperature alarm, deal with it step by step according to the troubleshooting method of the water chiller not cooling as described in the first point. For an over – low – temperature alarm, check the refrigeration conditions of the compressor to see if there are parts that should be disconnected but are not. The factory – set over – low – temperature alarm of the controller is 4 degrees, and the over – high – temperature is 35 degrees. When the ambient temperature is higher than 35 degrees or lower than 4 degrees, an over – temperature alarm will also occur.
Ⅳ. Conclusion
Basic Refrigeration Cycle
Water chillers are an essential part of laser cutting machines, playing a crucial role in ensuring the stable operation, high – efficiency performance, and long lifespan of laser cutting equipment. By understanding the working principle of water chillers and being familiar with common malfunctions and their solutions, users can quickly troubleshoot problems, reduce downtime, and improve the overall productivity of their laser cutting operations. Regular maintenance and proper operation of water chillers are also key to preventing malfunctions and ensuring the continuous and reliable operation of laser cutting machines in various industrial applications.