Selection, Installation and Error Analysis of Industrial Chillers
1. Selection of industrial chillers
1. Temperature range
When choosing an industrial chiller, you should first consider the factory's requirements for the production temperature. The production temperature has extremely important practical significance for the selection and system composition of the chiller. For example, the chiller used for air conditioning and the chiller used for low temperature engineering often have fundamental differences.
2. Refrigeration and stand-alone cooling capacity
The size of the cooling capacity of the chiller is directly related to the energy consumption and economic effect of the entire unit, which is worthy of attention. Especially when designing a cold station, a single chiller is generally not set up. This is mainly to consider that when a chiller fails or is shut down for maintenance, production will not be stopped, but a reasonable unit should be selected according to the production situation. number of units.
3. Energy consumption
Energy consumption refers to electricity consumption and steam consumption. Especially when choosing a large industrial chiller, the comprehensive utilization of energy should be considered. Because a large chiller is a device that consumes a lot of energy, for a large refrigeration station for cooling, it should fully consider the effects of electricity, heat and cold. In order to achieve the best economic effect, special attention should be paid to the full utilization of waste steam and waste heat.
4. Environmental protection
When choosing a chiller, environmental protection issues must be considered to facilitate production, scientific research and life requirements. For example, the following should be paid attention to: noise occurs when the chiller is running, and the noise value increases or decreases with the size of the chiller; some refrigerants used in chillers are toxic, irritating, flammable and explosive; some refrigeration The agent will destroy the ozone layer in the atmosphere, and when it reaches a certain level, it will bring disaster to human beings.
5. Vibration
The chiller will vibrate when it is running, but the frequency and amplitude vary greatly depending on the type of unit. If there is a requirement for anti-vibration, a chiller with a smaller amplitude should be used, or the foundation and pipeline of the chiller should be damped.
6. The quality of cooling water
The quality of the cooling water has a great influence on the heat exchanger, and its effect on the equipment is scaling and corrosion, which will not only affect the reduction of the cooling capacity of the chiller, but also lead to blockage and damage of the heat exchange tube in severe cases.
2. Precautions for installation of industrial chillers
1. Before installation, carefully check whether the chiller equipment is damaged, and then choose a suitable place.
2. The installation site of the chiller unit is the floor, installation pad or foundation, and can bear the overall weight of the equipment.
3. The chiller should be placed in a room with a room temperature of 4-40 degrees, leaving enough space around the unit to facilitate future maintenance and management.
4. One end of the chiller should have space for cleaning the condenser tube bundle, which cannot be occupied by other equipment in the workshop.
5. Select the appropriate water pipe diameter, which can withstand the pressure of the cooling system when the chiller is running at the maximum power, and connect it correctly.
6. For common application scenarios, the water flow speed through the condenser is between 1.0-3.6m/s, and the water flow should be stable under any load conditions.
7. Pipeline design and installation are carried out in accordance with conventional methods. The chilled water pump is connected to the water inlet pipe of the chiller to ensure the positive pressure and flow in the unit, and to maintain a certain shock absorption effect to prevent the water in the evaporator from being drained due to the shutdown of the pump. .
8. The fixing of the pipeline and the unit should be separated, and the hanger cannot be fixed at the same time. Avoid stressing the components of the chiller to create a burden.
9. Analyze and deal with the quality of the cooling water of the evaporator and condenser. If the water quality is poor, the structural materials of the larger sewage system should be selected to reduce water fouling, precipitation, corrosion, etc. that affect the heat transfer of the system, reduce the performance of the unit, and increase the operation. and maintenance costs.
10. Install cooling water filter, clean and maintain regularly to improve water quality.
11. After the leak test of the industrial chiller equipment is completed, the pipe port should be treated with anti-rust treatment.
3. Precautions for the operation of the chiller:
1. The chiller operator must be trained and mastered the skills, and the operation of the chiller should abide by the safety operation rules.
2. Do it carefully before work, check whether the cooling water valve has been opened, the water tank of the chiller and the water pressure of the cooling water are normal, otherwise do not run without water; carefully check the status of each pipeline before work, and make sure it is correct. Turn on the chiller.
3. The opening sequence of the water chiller: turn on the cooling water pump and turn on the compressor; the closing sequence of the water chiller: turn off the compressor and turn off the cooling water pump;
4. Do not set the temperature of the frozen water too low. Too low temperature will reduce the refrigeration efficiency of the unit, and may cause the low temperature protection action to alarm and stop. Just set the water temperature to a slightly lower temperature than the required temperature, and operate it if necessary. Side adjustment, adjust the water temperature according to actual needs;
5. When the unit fails and alarms and stops, first press the stop button of the unit (the alarm light will go out), and then check the cause of the failure, and do not force it to run until the fault is eliminated;
6. Do not shut down the unit by cutting off the main power supply unless it is an emergency; if the unit is out of use for a long time in winter, turn off the unit first, then turn off the main power supply, and drain the water in the system;
7. When an abnormal situation occurs in the chiller during operation, the power supply should be turned off immediately and the maintenance personnel should be notified to deal with it. Turn off the power of the chiller, clean the machine, clean and organize the work place;
4. Analysis of common faults of industrial chillers
Common faults 1. The industrial chiller leaks. First, the location of the leak should be determined and corresponding measures should be taken.
The reasons for water leakage are as follows:
1. The water inlet and outlet are loose or ruptured and water leakage occurs.
2. The water injection port is loose, causing water leakage when adding water.
3. The water injection bucket inside the industrial chiller ruptured and leaked.
4. The water outlet of the industrial chiller ruptures and leaks.
5. The internal water pipe ruptured, resulting in water leakage.
6. Water leakage occurs in the perforation of the condenser inside the industrial chiller.
7. The drain cap in the interface is broken or loose, resulting in water leakage.
8. The cooling water fluctuates and leaks during operation because the water tank is too full.
9. The external connection pipe is broken or the nozzle is uneven or the size is not suitable for water leakage.
The solution to the leakage of industrial chiller:
1. If it is found that the water leakage of the industrial chiller is caused by the rupture or loosening of the drain cap in the interface, the user can replace it by himself;
2. The water leakage of the industrial chiller is because the water injection is too full. You can open the water outlet of the industrial chiller to adjust the water level to the minimum liquid level line of the water level gauge;
3. If the water pipe orifice of the external connection of the industrial chiller is uneven or the water pipe is broken or the size is not suitable for water leakage, the water pipe orifice can be repaired or the water pipe of suitable size can be replaced.
Common faults 2. The industrial chiller does not refrigerate. The reasons include the industrial chiller system leaking refrigerant, the compressor is broken, the computer board is broken, and the refrigeration system is overloaded.
1. If the refrigerant is leaking from the industrial chiller system, first check whether the low-pressure gauge of the industrial chiller has pressure. If there is no pressure, it means that the refrigerant is leaking. Check the leakage and repair the leakage. Check the connection of each copper pipe to see the type of water leakage at that location. Just fill that spot.
2. If the compressor of the industrial chiller is broken, the machine shows that the compressor is faulty. Use a clamp meter to clamp the three wires of the compressor to obtain the working current. If the three wires are different, it is preliminarily judged that the compressor is bad. For example, the normal current of the compressor of a 10HP industrial chiller is 18A-20A, otherwise it is abnormal, indicating that the compressor is broken, and the solution is to replace the compressor of the industrial chiller.
3. If the computer board of the industrial chiller is broken, the temperature displayed on the computer board is abnormal, or does not match the actual temperature. The solution is to replace the computer board of the industrial chiller.
4. If the refrigeration system of the industrial chiller is overloaded, the temperature cannot reach the predetermined effect during the use of the industrial chiller, or the temperature does not drop, but instead rises, indicating that the power of the optional industrial chiller is not large enough. The solution is to replace the larger industrial chiller to reach the temperature of the water required in the production process.
Common faults 3. The industrial chiller reports a low-pressure fault, which causes the industrial chiller to fail to work normally. The reasons are insufficient refrigerant, blockage of the filter, too much fouling on the copper tube of the condenser, and too small opening of the expansion valve.
1. Insufficient refrigerant, the solution: leak detection, is there any leakage point in the pipeline joint? Replenish refrigerant after repair.
2. The filter is blocked, the solution: disassemble and wash or replace the filter.
3. The copper tube of the condenser has a lot of fouling, the diameter becomes smaller, and the heat dissipation is poor. Solution: Clean the condenser copper tube.
4. The opening of the expansion valve is too small, the solution: reduce the opening degree of the expansion valve appropriately, and automatically reset the high and low pressure protection after exclusion.
In addition, the selection of the chiller must be accurate. If the model is not in place, it will also fail to achieve the required cooling effect. It is recommended that when purchasing a chiller, provide the required cooling capacity and other parameters to the chiller manufacturer, discuss and obtain the chiller model, determine the chiller installation plan, achieve the predetermined cooling effect, and improve production efficiency.
Common faults 4. High pressure alarm of industrial chiller. After reset, start the machine and look at the high pressure gauge. If the pressure keeps rising, there will be a high pressure alarm. This kind of failure is generally not caused by the equipment manufacturer's problem. Users can solve the problem from the following aspects:
1. The cooling water is not turned on. This problem is very easy to solve, but it is a common mistake. Solution: Please open the water valve.
2. The cooling water flow is too small or the temperature is too high. Solution: increase the cooling water flow or reduce the water temperature (cooling water allows 21-38 degrees).
3. The copper tube of the condenser has a lot of fouling, small diameter and poor heat dissipation. Solution: Clean the condenser copper tube.
4. Too much refrigerant. Solution: discharge excess refrigerant (R22)
5. Expansion valve opening is too large. Solution: appropriately reduce the opening degree of the expansion valve, press the compressor thermal relay protection switch (RESTET), and restart the machine after finding out the cause.
