Advantages and disadvantages of piston chillers

According to the different types of chiller compressors, industrial chillers can be divided into fully enclosed scroll chillers, semi-enclosed piston chillers, and semi-enclosed screw chillers. All kinds of compressors have their advantages and disadvantages. Today, Omar Refrigeration will take you to talk about the advantages and disadvantages of piston chillers.

Piston chiller is a chiller with semi-hermetic piston compressor as the main engine. The unit is composed of refrigeration compressors, condensers, evaporators, thermal expansion valves, etc., and is equipped with automatic energy regulation and automatic safety protection devices. The piston compressor device system is relatively simple, and this type of compressor is generally used more in low temperature conditions. For general piston compressors, the brands we use are Bitzer Semi-hermetic Piston compressor, Copeland Semi-hermetic Piston compressor, or Dorin semi-hermetic Piston compressor.

Advantages of piston chillers:

1. Wide range of applicable pressures; strong maintainability.

2. Using multi-head, high-speed multi-cylinder, the performance can be improved.

3. The material is simple, the general metal material can be used, the processing is easy, and the cost is lower than that of the screw chiller.

Determination of piston chiller:

1. There are many parts and wearing parts.

2. The compression ratio is low, the cooling capacity of a single machine is small, and the cylinder unloading adjustment cannot be adjusted steplessly.

3. It has a reciprocating motion up and down, and the vibration is large, and the weight index per unit cooling capacity is large.

4. It is very sensitive to liquid shock.

The effect of temperature on electroplating production is very important. If the temperature of the electroplating process is not well controlled, the quality of the coating on the surface of the electroplating products will be greatly affected. Temperature regulation and cooling, constant temperature insulation, so as to stabilize the production and efficiency of electroplating. Therefore, the surface treatment chiller, namely electroplating chiller, is commonly known as refrigerator, freezer, chiller, ice water machine, cooler, etc. So what are the characteristics of electroplating chillers?

The special chiller for electroplating generally chooses an air-cooled box-type chiller, which is easy to install and move, without a cooling tower, and is generally installed next to the electroplating equipment. The electroplating chiller uses two cooling methods, one is direct cooling and the other is indirect cooling. Due to the particularity of the electroplating industry, the electroplating solution is corrosive, so the evaporator, pipeline, water tank, Water pumps are all made of anti-corrosion stainless steel, and heat exchangers are generally made of titanium tubes to meet the needs of long-term stable use. It helps to stabilize the metal ions, make the metal ions quickly attach to the electroplated parts, continuously increase the density and smoothness, reduce the number of electroplating, and improve the productivity.

Oumalchiller specializes in industrial cooling systems, providing customized industrial cold water system solutions, providing various industrial chillers, plastic industry chillers, electroplating industry chillers, pharmaceutical industry chillers, food industry chillers, surface treatment chillers, welcome to consult .

The exhaust temperature of the compressor is the temperature of the exhaust gas after the compressor does work (compresses the gaseous refrigerant). It is usually fixed within a range. By observing the temperature change, the working condition of the compressor can be predicted and the occurrence of safety-threatening events can be prevented. . The exhaust temperature is an important parameter in the operation of the refrigeration compressor of the industrial chiller, and it must be strictly controlled. If the exhaust temperature is too high, it will cause the special refrigeration compressor of the industrial chiller to overheat, especially for the piston of the piston chiller. Refrigeration compressors have a serious impact, and the main hazards are shown in the following aspects.

1. Excessive exhaust temperature of the compressor will directly reduce the gas transmission coefficient, increase the shaft power, and reduce the viscosity of the lubricating oil, which will cause abnormal wear on the bearings, cylinders, and piston rings, and even cause burning of bearing bushes and cylinders.

2. Once the exhaust temperature of the compressor is too high, it will directly lead to thermal decomposition of lubricating oil and refrigerant under metal catalysis, and generate acid substances, free carbon and moisture that are harmful to the compressor. Free carbon is deposited on the exhaust valve, which not only destroys its tightness, but also increases the flow resistance. If the carbon residue of the pineapple is taken out of the compressor, it will block the capillary and the dryer. Acids will corrode various components of the chiller refrigeration system and electrical insulating materials, and moisture will block capillaries.

3. The chiller operator should check the overheating of the compressor. If the overheating is serious, the piston will be over-expanded and stuck in the cylinder, and it will also cause the built-in motor of the hermetic compressor to burn out.

4. The high discharge temperature of the compressor will directly affect her service life, because the chemical reaction speed will increase with the increase of temperature. Generally, the temperature of the electrical insulating material will rise by 10℃. Then her service life will be reduced by half , which is particularly important for hermetic compressors.

Causes of overheating of compressor discharge temperature:

1. The refrigeration system is short of oil

Insufficient supply of lubricating oil and lack of oil in the system will cause the machine head to not be properly cooled, resulting in an increase in exhaust temperature. By checking the oil level of the lubricating oil, it can be judged whether the lubricating oil is sufficient, and an appropriate amount of lubricating oil should be added according to the equipment regulations. If the oil separator is damaged, replace it.

2. The temperature control valve fails to work

The function of the temperature control valve is to automatically control the opening and closing of the valve according to the oil temperature. If there is a fault, the lubricating oil is directly sprayed into the machine head without passing through the condenser, which will cause the exhaust temperature to rise. The solution is to check and repair and replace the thermostatic valve.

3. The quality of lubricating oil deteriorates

Deteriorated lubricating oil will cause the oil film of the screw compressor to become thinner and not form a sufficient lubricating oil film, resulting in abnormal operation of the compressor, abnormal noise, etc. The solution is to replace the oil with new oil.

4. The cooling system is blocked and the heat dissipation is poor

Blockage or poor heat dissipation of the cooling system will cause internal scaling, resulting in poor heat dissipation, resulting in the inability of exhaust heat to dissipate, resulting in high temperature; similarly, damage to the cooling fan will also cause the cooling system to fail to dissipate heat in time.

The solution is to check the cooling system, remove dirt or repair the exhaust fan.

5. Detect control pipeline failure

This is caused by blockage of the air filter, failure of the temperature detection system, abnormal operation of the unloading valve, etc.

The solutions are: cleaning or replacing the air filter; checking whether the increase in the unit load causes over-temperature; checking the working condition of the unloading valve and adjusting it; testing, repairing, and replacing the system temperature detection system circuit.

The industrial chiller machine has become one of the essential equipment for cooling in most production enterprises, and the screw chiller is a large-scale industrial refrigeration equipment. Screw chillers are divided into air-cooled screw chillers and water-cooled screw chillers. Compressors, condensers, and evaporators are important components of screw chillers. When purchasing a screw chiller machine, you must first understand the main control parameters of the screw chiller, such as refrigeration coefficient, cooling capacity, refrigerant, input power, etc. When choosing a screw chiller, we must consider the cooling capacity, the user's operating voltage, the outlet water temperature, and the condensing temperature. Use this to determine the model of the compressor, as well as the energy of the evaporator and condenser.

The actual cooling capacity of the screw chiller equipment is related to the following factors:

1. Chilled water outlet temperature and the water flow

2. Inlet water temperature, flow rate and fouling coefficient of cooling water

When choosing a screw compressor chiller, in addition to considering the cooling capacity, the installation environment should also be considered. In this way, it is determined whether to choose an air-cooled screw chiller or a water-cooled screw chiller. Under the same cooling capacity requirement, the energy efficiency ratio of the water-cooled screw chiller is higher than that of the air-cooled screw chiller. Therefore, There will be differences in the model of the compressor, which leads to the higher cost of the compressor of the air-cooled screw chiller than that of the water-cooled screw chiller, and the cost of the air-cooled condenser is also higher than that of the water-cooled shell and tube condenser. So how to determine whether to choose a water-cooled screw chiller or an air-cooled screw chiller?

From the perspective of the purchase cost of the screw chiller, the price of purchasing a water-cooled screw chiller is lower than that of an air-cooled screw chiller.

If you consider the installation environment, the air-cooled screw chiller is easy to install, without the need to install a cooling tower, and it is suitable to install the air-cooled screw chiller in places where water resources are scarce.

From the perspective of the maintenance of the screw chiller, the later maintenance cost of the water-cooled screw chiller is higher, and the technical requirements are higher. If there is no professional staff, in the process of installing and using the water-cooled screw chiller, It is easy to cause various problems in the chiller due to problems such as water flow, while the maintenance of the air-cooled screw chiller is relatively simple. Regularly clean the condenser and check the machine regularly.

Through the above analysis, do you know how to choose a suitable screw chiller? If you don't know how to choose when purchasing a screw chiller, Call us： +86 15112554736 to get the professional suggestion.

An important step in the commissioning of screw chillers and scroll chillers is the charging of refrigerant. Generally, Oumal screw chillers are filled with the specified type of refrigerant before leaving the factory. After the chiller arrives at the chiller installation site, first check whether the screw chiller is damaged during transportation, check the high and low pressure gauges, and confirm whether the chiller is in good condition. If it is found that the refrigerant is insufficient or leaking, you need to find out the leak place and fix it, and then add the specified type of refrigerant according to the product instructions. For some screw chillers, the refrigerant needs to be emptied for transportation due to transportation problems. Therefore, after the machine arrives at the installation site, the refrigerant needs to be added again, and the appropriate refrigerant must be added according to the manufacturer's requirements. Before adding refrigerant, the air in the screw chiller system should be evacuated before adding refrigerant.

In the debugging process of the screw chiller, the following issues need to be paid attention to the following points: .

1. Check whether the valves in the refrigeration system are in normal opening state, especially the exhaust shut-off valve, do not close it.

2. Open the cooling valve of the condenser and the cold water valve of the evaporator, and the flow of chilled water and cooling water should meet the requirements of the manufacturer.

3. Before starting, observe whether the power supply voltage of the unit is normal.

4. Start the unit according to the installation instructions provided by the screw chiller manufacturer,

5. The safety protection installed in the refrigeration system should be used correctly, such as high and low pressure protection devices, water flow switches for chilled water and cooling water, safety valves and other components. If damaged, they should be replaced in time.

6. If an alarm occurs in the screw chiller, it should be stopped immediately for inspection. If it cannot be solved, contact the chiller manufacturer in time.

If you have purchased an Oumal screw chiller and do not know how to debug it, please contact your salesperson directly to guide the installation online.

If you have more questions of the debugging the chiller and installation the water cooled screw chiller, please email: oumal@oumal.com or contact Whatsapp: +86 15112554736.

Generally speaking, everyone will have doubts when purchasing a chiller. I don't know how to judge the chilled water flow of the chiller? From what aspects should the water flow of the chiller be considered? Today I would like to share with you four suggestions:

1. Detection of return water temperature and outlet water temperature of the chiller (the unit needs to be in normal state):

30 minutes after starting up the unit, you can read the temperature of the inlet and outlet water when the unit is running through the parameters of the unit's control system or the inlet and outlet water thermometers of the unit's chilled water system. The difference should be ensured to be about 4-6 degrees. If the water temperature difference is too large, it means that the water flow of the water system through the plate type device is too small, which may cause the unit to fail to operate normally or be damaged.

2. Water pressure detection of the inlet and outlet pipes of the chiller unit:

Through the detection of the return water pressure and the water outlet pressure value, check the water flow rate of the chiller under the pressure difference between the inlet and outlet water in the random manual of the unit. In order to judge whether the water system is normal; and through this difference to judge which section of the water pipeline resistance value is too large, and make corresponding rectification plans and actions.

3. Detection of the suction temperature of the copper tube of the compressor (only in the cooling operation):

If the suction temperature of the compressor is detected to be lower than 0 degrees after the refrigerating chiller is turned on for 30 minutes, it means that the water flow in the water-side heat exchanger is insufficient, resulting in a drop in the evaporating temperature and evaporating pressure, and causing freon to flow in the direction of the evaporator. The suction pipe of the compressor is still evaporating and absorbing heat, which will cause the suction temperature of the compressor to be lower than 0 degrees; in addition, it is necessary to eliminate the drop of evaporating pressure and evaporating temperature caused by the low water temperature set point; The low water temperature unit can be considered normal as long as the compressor has a suction superheat of 6 to 8 °C. Therefore, under normal water flow, the suction temperature of the compressor will generally be greater than 0 °C, below this value, the problem of the water system needs to be eliminated.

4. Water pump running current detection:

By detecting the running current of the chiller water pump and comparing it with the rated current, it can be judged whether the actual water flow rate is larger or smaller than the rated water flow rate of the water pump. Only by making a comprehensive judgment with the previous parameters can an exact water system detection and analysis be obtained. Judgment report.

Spot welding machine is a kind of mechanical equipment. It adopts the principle of double-sided double-point overcurrent welding. When working, two electrodes pressurize the workpiece so that the two layers of metal form a certain contact resistance under the pressure of the two electrodes, and the welding current changes from one When the electrode flows through the other electrode, the two contact resistance points form an instant thermal fusion, and the welding current flows from the other electrode to the electrode along the two workpieces to form a loop instantly, and will not damage the internal structure of the welded workpiece. Because the resistance welding machine is in the working process, the resistance head is prone to high temperature, which affects the accuracy of the processed product, so a chiller is needed to cool it next to ensure the accuracy of the processed product. The spot welding machine is equipped with a chiller, which can improve the safety and stability of the welding work and extend the life of the welding machine.

Industrial chillers used for spot welding operate like recirculating coolers as they use the same closed-loop setups. However, process chillers can be modified to handle industrial cooling on a larger scale. Industrial chillers also have condensers, evaporators, and automated temperature controls that make them more efficient. Air cooled chiller is a good choice for spot welding machine, It’s easy to installation and move.

A general rule for sizing a chiller is that, for every 100KVA of welder, you should have about a 1-ton chiller. For example, if you want to cool 4 welders that are 100KVA each, you will need a 4-ton chiller. If you want to cool a 300KVA machine, you will need a 3-ton chiller. See below for further sizing details.

To calculate for resistance welding:

BTU/hr = (welder KVA) x (duty cycle) x (0.85) x (0.6) x 3415 BTU/hr

To calculate for resistance welding:

BTU/hr = (welder KVA) x (duty cycle) x (Eff power supply) x (Eff heat collection) x 3415

Eff. power supply = the percentage of output to input power

Eff. heat collection = the percentage of heat absorbed by chilling water (varies by approximately 50-70%)

Duty cycle = weld time on/ time elapsed

As a leading industrial chiller manufacturer, OUMAL CHILLER is dedicated to supplying high-quality process chillers for a wide range of industries. Our knowledgeable staff will help you find the industrial chiller best suited to your unique process application. Contact us to choose the spot welding cooling system for your spot welding machines. The air cooled chiller is your good choice for Industrial welding chillers.

Industrial Chillers are widely used, providing cooling water systems for industrial production and helping companies improve product output and quality. Therefore, we need to understand how to use chillers simply and correctly to avoid problems during use and delay production. Let us briefly understand the use of chillers from the following aspects.

One: the protection of the chiller:

1. Check whether the voltage is normal, lack of phase,

2. Check and record the running current.

3. Measure and record whether the high and low pressure and temperature control temperature are normal.

4. Under normal conditions, the high pressure is 1.5MPa / the low pressure is 0.45MPa4 Check whether the interlocking control circuit device is loose and aging.

5. Check whether the oil level and oil temperature are normal.

6. Check the compressor for abnormal sound and abnormal vibration.

7. Refrigerant system test.

8. Overall commissioning and testing.

9. Regularly check whether the quality of the chilled water and cooling water is normal. When the water quality of the water source becomes dirty or degenerated, please replace the water source in time.

Two: The annual maintenance of the chiller is as follows:

1. Clean the condenser (every six months of cumulative operation)

2. Cleaning the cooling tower (the water-cooled chiller should be cleaned once every three months after accumulative operation)

3. Check the refrigeration oil and lubricating oil system, and replace and supplement the industrial chiller if necessary.

4. Check the circuit system of the water chiller system.

5. Compressor motor coil insulation test for industrial chillers.

6. Check whether the filter drier is normal or not, and replace it if necessary.

Three: the precise use of chillers knowledge:

7. Check the amount of refrigerant and replenish refrigerant in time.

8. Check and correct the high and low pressure switches.

9. Check and calibrate the thermostat.

10. Test run and general calibration, test whether the superheat is normal and whether there is abnormal sound of each component.

Generally, water cooling (that is, natural water and water tower cooling methods) cannot achieve high precision and high efficiency.

The purpose of temperature control, because natural water and cooling tower heat dissipation are inevitably affected by natural air temperature, the water temperature in winter is low in summer, and the water temperature is high in summer. If the air temperature is 30°C, it is almost impossible for the water temperature to reach 10°C, so it is extremely unstable to control in this way. The water chiller is completely different from the general water cooling equipment, because the chiller has a completely independent refrigeration system, which will never be affected by the temperature and the environment. The purpose of high-efficiency temperature control. The chiller is equipped with an independent water circulation system, and the water in the chiller is recycled, which can save a lot of water. Therefore, industrial production is inseparable from industrial chillers. Oumal specializes in the production of industrial chillers to help companies provide industrial chilled water system solutions. Contact us if you are looking for a solution for your industrial chilled water system.

There are many parts of the screw chiller, among which there are several major components, namely the compressor, condenser, evaporator and microcomputer control system of the screw chiller. The operation panel and computer control system of the screw chiller are very important. Therefore, the four parts of compressor, condenser, evaporator and microcomputer control system are the core parts of screw chiller. Let us discuss these four components in detail.

1. Compressor

As the name suggests, the screw chiller uses a semi-hermetic screw compressor as the compressor of the chiller. There are several major brands of screw compressors we use, such as Hanbell compressors from Taiwan, Bitzer compressors from Germany, or Fusheng compressors from Taiwan. These compressors have reliable quality, low failure rate and high energy efficiency ratio. In contrast to screw chillers, there are scroll chillers and piston chillers. The main brands are Copeland, Danfoss, Bitzer, etc. We won't talk about them here.

2. Condenser

There are two types of condensers for screw chillers. The condenser of the air-cooled screw chiller is a fin type with an additional fan for heat dissipation, while the condenser of the water-cooled screw chiller is a shell and tube type. Therefore, the water-cooled screw chiller The chiller requires an external cooling tower to dissipate heat. Of course, whether it is a water-cooled screw chiller or an air-cooled screw chiller, the condenser must be sufficient to ensure the cooling effect of the chiller and reduce high-voltage failures.

3. Evaporator

Evaporator mainly depends on whether its energy loss is more or less, the less cooling loss is better, and the cooling effect is better. It also depends on whether the structure is compact and the performance is stable. We use shell and tube evaporators for the evaporators of screw chillers.

4. PLC control system

The configured screw chiller, its automatic control system is very high-end, menu-type buttons, and remote monitoring and control, which is very convenient. Such screw chillers can also make you more worry-free to use, even if Operators who don't know anything can use it normally with a little training, which is very user-friendly. Omar screw chiller adopts Siemens PLC control system, or PUNP LCD Touch Screen Control Panel. Omron is optional for client.

To learn more about OUMAL Screw Chiller, please contact us to get the detail information.

With the continuous improvement of domestic industrial production capacity, industrial chillers are more and more favored by enterprises. However, during the installation process of industrial chillers, some installation problems are often encountered. So how do we properly install an industrial chiller?

1. After unpacking the new machine, first check the accessories in the box according to the list, so as to avoid the failure of normal installation of the chiller due to the lack of accessories. After confirmation, follow the installation drawings and installation sequence provided by the chiller manufacturer. The water-cooled chiller needs to be installed with a cooling water system. After the cooling tower pipeline is installed, ensure that the water circulation is normal.

2. Please ensure that the working voltage of the chiller is stable and normal. Make sure the power socket is in good contact and the ground wire is grounded reliably. It is necessary to pay attention to whether the power cord socket of the chiller is connected well and the voltage is stable. The normal working voltage of Omar standard chiller is 3ph-380V-50Hz. If it is indeed a special working voltage range, it can be customized separately. If the power frequency does not match, the machine will be damaged. Please use the 50Hz or 60Hz model according to the actual situation.

3. Check the installation environment and keep away from all kinds of flammable and explosive substances. The installation site of the unit must be the floor, installation pad or foundation, and its horizontal height should be within 6.4mm and can bear the operating weight of the unit. The unit should be placed in a computer room with a room temperature of 4.4-43.3°C, and there should be enough space around and above the unit for routine maintenance. One end of the unit should have space for the exhaust pipe for cleaning the condenser tube bundle, or a door hole or other suitable holes can be used. When the water source and the surrounding environment of the cooling water tower are harsh, the chilled water and cooling water circuits must be installed with Y-type filters and cleaned regularly. The highest part of the closed chilled water system must be installed with an automatic exhaust valve, and the lowest part of the system must be installed with a drain joint for the system to use. If it is an air-cooled chiller, it is necessary to ensure good ventilation and heat dissipation around the chiller fan port. Please ensure that the air inlet and outlet passages of the chiller are smooth, the air outlet above the chiller should be at least 50cm away from the obstacle, and the air inlet on the side should be at least 30cm away from the obstacle.

4. It is strictly forbidden to run without water. The water storage tank will be emptied before the new machine is packed. Please ensure that the water tank is filled with water and then turned on, otherwise the water pump will be easily damaged. The water-cooled chiller must ensure that the cooling water system circulates well.

Omar will provide guidance before the customer installs the chiller. If the customer does not know how to install the chiller after receiving the chiller, please contact our chiller sales and we will provide professional help. Email : oumal@oumal.com