Chapter 1: What is water chiller

In the refrigeration industry, water chillers can be divided into the air-cooled chiller and water-cooled chiller. According to the compressor, it is divided into screw chiller and scroll chiller.

A water chiller is a kind of water cooling equipment, which can provide constant temperature, constant current and constant pressure, our water chiller are ranged from 2 Ton to 60 Ton in cooling capacity and chilled water flow rate is up to 680 LPM

Cooling water temperature can be adjusted automatically according to the requirements, temperature controlling range of water chiller are from 7℃ to 35℃，and water can be saved by long-term use. Therefore, water chiller is a kind of standard energy-saving equipment.

More generally, you can always output chilled water with a lower temperature than the environment. You can use it whenever you need to cool down. It can be cooled directly or by heat exchanged indirectly.

The water chiller consists of four main components: compressor, evaporator, condenser, expansion valve, so as to achieve the cooling effect.

In the industrial field, water chiller is one of the most commonly used refrigeration equipment. Water Chiller plays an important role in industrial refrigeration. Many water chillers are controlled by microcomputers, which are easy to operate, high precision, a wide range of use and can accurately control water temperature.

At the same time, the perfect electrical protection system has the protection of phase absence, phase staggering, current overload, high and low voltage, compressor exhaust overheating, etc. to ensure the efficient operation of chillers.

Chapter 2: How does a water chiller working

The operation of the water chiller system is accomplished by three interrelated systems: Water chiller refrigerant-cycle system, water cycle system and electrical automatic control system.

2.1 Water chiller refrigerant cycle system:

The liquid refrigerant in the evaporator absorbs the heat in the water and starts evaporating. It becomes gaseous and then is inhaled and compressed by the compressor (pressure and temperature increase), and then transported to the condenser.

The high-temperature pressure gaseous refrigerant releases heat through the condenser (water-cooled), condenses into liquid and becomes a low-temperature and low-pressure refrigerant after saving pressure by the thermal expansion valve (or capillary tube).

After entering the evaporator to absorb heat in water, a cycle process of refrigerant was completed. Refrigerants circulate in such a way that they constantly take heat away from the water and then reach the intent of cooling water.

2.2 Fundamental  composition of water chiller

2.2.1 Compressor

The compressor is the core component of all water chillers, and also the power source of refrigerant compaction. Its effect is to convert the input electric energy into mechanical energy and to tighten the refrigerant.

2.2.2 Condenser

The condenser acts to output thermal energy and condenses the refrigerant during the cooling process. After the high-pressure superheated vapor discharged from the refrigeration compressor enters the condenser.

it absorbs all the heat in the operation process, including the heat absorbed from the evaporator and the refrigeration compressor and in the pipeline, which is transferred to the surrounding medium (water or air); the high-pressure superheated vapor of the refrigerant condenses into liquid again.

2.2.3 Liquid reservoir

After the condenser, the Liquid reservoir device is directly connected with the discharge pipe of the condenser. The refrigerant liquid of the condenser should flow into the reservoir in all directions so that the cooling area of the condenser can be fully utilized.

On the other hand, when the heat load of transpirator changes, the requirement of refrigerant liquid also changes. At that time, the reservoir will play the role of adjusting and storing refrigerants. Regarding small refrigeration equipment system, the condenser is usually used to adjust and store refrigerants instead of the liquid reservoir.

2.2.4 Dryer filter

It is necessary to prevent moisture and dirt (oil, iron, copper) from entering the refrigeration cycle. The origin of moisture is mainly the trace moisture contained in the newly added refrigerant and lubricating oil or the moisture brought by the air entering into the maintenance system.

If the water in the system is not cleaned, when the refrigerant passes through the saving valve (thermal expansion valve or capillary), sometimes the water will condense into ice due to the decrease of pressure and temperature, which will block the passage and affect the normal operation of refrigeration equipment.

2.2.5 Thermal expansion valve:

The thermal expansion valve is not only a flow regulating valve in a refrigeration system, but also a saving valve in refrigeration equipment.

It is installed between the dry filter and evaporator in refrigeration equipment, and its temperature sensor is wrapped at the outlet of the evaporator.

Its primary effect is to make the refrigerant liquid at high pressure and normal temperature save pressure when flowing through the thermal expansion valve, and turn into low temperature and low-pressure refrigerant wet vapor (some are liquid, some are steam) into the evaporator， vaporize and absorb heat in the evaporator, and reach the intention of cooling.

2.2.6 Evaporator

The evaporator is a heat exchanger which absorbs the heat of the cooling medium by the transpiration of refrigerant liquid (actually boiling). Its function in the refrigeration system is to absorb heat (or output cooling).

In order to ensure that the transpiration process can proceed steadily and durable, it is necessary to constantly use refrigeration compressor to extract transpiration gas, in order to maintain a certain transpiration pressure.

Most water chillers used in modern industry use refrigerant R22 or R134a and R407c, Refrigerants are active refrigerants in refrigeration systems.

Their primary effect is to carry heat and to achieve heat absorption and release when conditions change.

2.3 The water circulation system

The water circulation system is a pump that draws water from the water tank to the equipment that the user needs to cool. After the heat is taken away by the chilled water, the temperature increases and then returns to the chilled water tank.

Chapter 3: The difference between Water chiller and Air chiller

The air-cooled chiller realizes the refrigeration function by refrigeration cycle cooling water of the chiller.

Because of the heat exchange between the fan and the air, therefore, air-cooled water chillers also use a fan, dust-proof net, and other heat dissipation components to carry out heat dissipation.

Air-cooled water chiller can control temperature while maintaining stable performance, occupying small space, easy to move, easy to operate.

The water-cooled chiller cools the circulating water through the chiller’s refrigeration system and then delivers it to the equipment through the pump and the cooling water route.

The water-cooled chiller is relatively less affected by the environment, but the company needs a good quality water source for circulation cooling.

Due to the water tower, the water-cooled chiller occupies a large area, and the installation and maintenance workload is large.

The following is specific differences between the air-cooled chiller and the water-cooled chiller.

3.1 Cost

Because the heat exchange efficiency of water is much greater than the air exchange efficiency, the water-cooled chiller is more energy efficient than the air-cooled chiller.

Compared with the water-cooled condenser with the same heat transfer capacity, the air-cooled condenser has a larger volume, more materials, and higher manufacturing cost.

The total cost of water-cooled chillers is still 15-20% lower than that of internal-cooled chillers even if the equipment cost of the cooling water system is added.

In addition, because the nominal power of the air-cooled unit is larger than the nominal power of the water-cooled unit, the cost in terms of power capacity increase and electronic control equipment is also high.

3.2 Performance

The heat transfer temperature difference of the water-cooled unit condenser is generally 4℃-8℃, while the air-cooled chiller has a heat transfer temperature difference of generally 8℃-15℃ in the same outdoor ambient temperature.

The temperature of the cooling circulating the water is lower than the outdoor air temperature, so the condensing temperature of the air-cooled unit in normal operation is much higher than the condensing temperature of the water-cooling unit.

So that the air-cooled unit consumes more powerful in refrigeration than the water-cooled unit under the same cooling capacity.

3.3 Equipment room

For water-cooled chillers, the machine room should be provided to ensure that the normal operation and service life of equipment including chillers and chilled water circulating pumps, and cooling tower equipment should be placed on the roof or outdoor floor of buildings.

It can be seen that, in the case that the building cannot provide a machine room, the selection of air-cooled chillers should be a better way.

3.4 Operation cost

Because the water-cooled chiller operates at a lower condensing temperature, the refrigeration efficiency is high and the power consumption of the unit is small.

Generally speaking, compared with air-cooled units with the same refrigeration capacity, the overall power consumption of water-cooled units is about 25% lower than that of air-cooled units (including the power consumption of cooling water pumps and cooling tower fans).

3.5 Regular Maintenance

Shell-and-tube condensers used in water cooled chiller units have a low impact on heat transfer efficiency within a certain range of fouling accumulation, so the performance of units decreases slightly with fouling generation, and the cleaning cycle is longer.

The heat transfer efficiency of the finned condenser used in air-cooled water chillers is greatly affected by the accumulation of dust. The dust grids must be set before the fin tubes for heat dissipation, and frequent cleaning is required.

Because of the high operating pressure of air-cooled units, they are usually installed outdoors, and the operating environment is relatively harsh. They are inferior to water-cooled chillers in terms of maintenance and reliability.

Some tips of water cooled chiller maintenance

1. Do not shut down the water cooled chiller by cutting off the main power supply in case of emergency.

2. When the water-cooled chiller fails to alarm and stop, first turn off the main power switch of the machine (the alarm lamp will be extinguished), and then check the cause of the failure. The water cooled chiller must not be forced to start before the failure is eliminated.

3. In order to prolong the water cooled chiller life of the system and prevent the occurrence of safety accidents, the regular inspection must be carried out.

4. The water quality of the system should be treated. The high alkaline water quality will aggravate the corrosion of copper tubes and reduce the service life of heat exchangers.

The PH value of the water used is in the range of 7.0-8.5. 5. Keep the room dry, clean and well ventilated.

5. The daily operation, management and maintenance of water cooled chillers must be carried out by people with professional skills. (It is dangerous to disassemble or inspect the machine when water cooled chiller is running, please note!)

6. Refrigerant gas leakage really happened with a water cooled chiller, If this problem happen, we should recharge some refrigerant.

Please follow the below sequence:

Filling Refrigerant:

Turn off the lid of the valve and connect the air pipe of the vacuum pump to the valve for vacuum pumping. The process takes about 1 to 3 hours.

After the vacuum is exhausted, the gas pipe of the refrigerant tank is connected to the needle valve and the refrigerant is added to the return pipe.

Monitor the change of electronic weighing and stop filling refrigerant when filling rated weight. (No liquid refrigerant in startup state) startup

Under the condition, the pressure of the high-pressure gauge is about 13-15 bars, and the pressure of the low-pressure gauge is about 3-5 bars.

Water-cooled chillers use shell-and-shell condensers, which accumulate scales on the inner side of heat transfer tubes for a long time, which affect their heat transfer effect.

The condensers should be cleaned regularly to keep the water-cooled chillers working well.

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If the cooling water has been treated as water purification, it is suggested to sterilize and remove algae with hydrogen peroxide, rinse ears with high-pressure water gun, and then check whether there is scale.

Passivation is necessary after pickling. Passivation can be purchased for relevant treatment. Ice water machine
When the water-cooled chiller stops in the environment below 0 C and is not used or stored, the pipeline should be disconnected, the front end of the machine should be improved, and the water wrapped in the ice condenser should be discharged strongly and nearly as cold as that wrapped in the ice condenser.

Shell-and-tube evaporator is used in ice water machine. Scale accumulates on the outside of the heat transfer pipe for a long time, which affects its heat transfer effect.

regularly cleans the evaporator to keep its good working performance. The evaporator is cleaned by cleaning the cold frost condenser. The scale is discharged from the drain.

Chapter 4: Water Chiller Industrial Applications

In industrial applications, industrial water chillers are used in a variety of industries to control products, mechanisms and plant machinery cooling.

Industrial water chillers are commonly used for injection and blow molding in the plastic industry, metalworking cutting oils, welding equipment, die casting and machining, chemical processing, food and beverage processing, paper making, cement processing, vacuum systems, X-ray medical equipment, and power stations, analytical equipment, semiconductors, compressed air and gas cooling.

Water chillers are also used to cool high-heat energy, such as nuclear magnetic resonance imaging and laser-specific engineering projects, and in hospitals, hotels and campuses.

Plastics industry: water chillers precisely control the mold temperature of various plastic processing, shorten the beer-plastic cycle, and ensure the stability of product quality.

Electronics industry: water chillers stabilize the molecular structure of electronic components in the production line, improve the qualified rate of electronic components, apply to the ultrasonic cleaning profession, and effectively avoid the damage caused by evaporation of precious detergents.

Electroplating industry: water chillers control the plating temperature, increase the density and smoothness of the plated parts, shorten the plating cycle, improve the output power, and improve product quality.

Machinery industry: water chillers control the pressure oil temperature of the oil pressure system, stabilize the oil temperature and oil pressure, extend the oil quality application time, improve the mechanical smooth power, and reduce wear.

Construction industry: water chillers provide chilled water for concrete, make concrete molecule structure suitable for building use request, and effectively enhance the hardness and durability of concrete.

Vacuum coating: water chillers control the temperature of the vacuum coating machine to ensure the high quality of the plated parts.

Food industry: water chillers Used for high-speed cooling after food processing to make it accustomed to packaging requests. Others include controlling the temperature of fermented food.

Chapter 5: Why are we a reliable Water Chiller supplier?

TopChiller, as the world’s leading water chiller manufacturer, we produce more than 5000 water chiller units annually and provides high-quality water chillers as our goal.

Here are some reasons why are we a reliable Water Chiller supplier

5.1 Rich experience and professional teams

Since TopChiller established in 1999, we have been accumulating experience in the field of chillers to provide high-quality chillers to customers around the world.

5.2 Chiller spare parts of internationally renowned brands

To ensure the high quality of water chillers, TopChiller uses internationally advanced compressors, such as USA Copeland, France Danfoss or Japan Sanyo, Germany Bitzer and Taiwan Hanbell, We strict control over every part, water pumps and condensers in chillers can be configured according to specific requirements.

5.3 Pre-sales and After-sales Service:

Our sales and technical team provide you with free support throughout the day, providing most professional and just-in-time technical consults and water chiller solution for you. When we get your inquiries，we will reply you within 5 hours, 18-month warranty is provided for our products, and contact us at any time during chiller whole lifetime service

Chapter 6: How to size a suitable water chiller for your machine

A water chiller is a kind of refrigeration equipment which can provide industrial chilled water for all industries to achieve the purpose of cooling.

It can control the temperature between 5 degrees and 35 degrees, and the low-temperature water chiller can control the temperature between 0℃ to -40℃ In the selection of chillers, we need to know exactly how much the inlet and outlet temperatures of chillers is, how much the flow rate is and how big the water tank is.

A water chiller with high quality is the guarantee of successful engineering design and has a long-term impact on the operation of the system.

Cooling water flow: refers to the cooling circulating water flow of the chiller that needs to be supplied when refrigerating equipment is used.

Cooling capacity: that is, how much refrigeration capacity is needed? The commonly used units of refrigeration capacity are Kcal/h, kw, etc.

Outlet-water temperature: return-water temperature or temperature difference between outlet-water and return-water: Outlet-water temperature refers to the temperature of chilled water，return-water temperature refers to the temperature of cooling water.

Some equipment with stricter heat dissipation requirements will have the temperature requirement of cooling water supply.

Outlet-water pressure: Because of the complex internal heat dissipation structure of some heat dissipation equipment, there is a certain pressure requirement for cooling water supply. At this time, it is necessary to consider whether the rated outlet water pressure of the chiller can meet this requirement.

Pump lift: If a single machine is used one-to-one, the pump lift should not be a problem. If multiple water-cooled chillers are connected in parallel for the application of multiple cooling types of equipment, the resistance of the pipeline system should be taken into account, so as to calculate how many pump lifts need to be allocated.

Control adjustment requirements: generally refers to pressure control adjustment and temperature control adjustment.

Safety protection function requirements of water chillers: A. Compressor delay start protector B. High and low voltage protection function C. Inverse phase protection D. Compressor overload protection E. Antifreeze protection F. Compressor overheat protection G. Compressor frequent start protector and abnormal indicator lights and various protection switches.

Chapter 7: Water Chiller installation guide

Installation of water-cooled chillers (mainly is basic vibration isolation equipment): We are well aware that the installation of equipment must choose a flat and open place, chillers are no exception.

Before installing water chillers, many users will do a good job of foundation preparation and embedding four horizontal pad iron in advance.

Generally, the water chiller has four legs, which can be equipped with an adjusting padding plate with two adjusting threaded holes to adjust the level of the whole water chiller, and use concrete mortar to fill in the gap after adjustment.

After the mortar is dried, the adjusting bolt can be removed, the positioning bolt can be left behind, and the fixing measures can be taken for the water chiller.

Installation of water chiller pipes: mainly are the external water pipes of evaporator and condenser, if it is double-return water pipes, it is arranged on the same side.

If it is single-return or three-return water pipes, it is arranged on both sides, The inlet and outlet water of water-cooled chillers’ condenser and evaporator are from bottom to top.

Note:

water chiller water pipe cleaning: After installing the water pipe to the unit, the whole water system should be tested for leakage. After the leakage test is qualified, the water pipe can be cleaned.

When cleaning water pipes, we should first make sure the direction of the pump is correct. and open all the valves of the inlet and outlet pipes. The pipes are full of water, start the chilled water pump and the cooling water pump, run continuously for two hours, stop the operation of the pump, drain all the cold water and cooling water, and clean the pump filters.

Chapter 8: Troubleshooting of water chiller

Each water chiller not only completes comprehensive performance testing before leaving the factory, but also equips the unit with various safety protection devices, such as phase protection, low water level protection, water flow switch protection, pump overload protection, compressor overload protection, high and low voltage protection, etc.,

so as to avoid secondary damage caused by the failure of the unit. When the unit fails to occur, the corresponding protection device will give a warning and stop the water chiller operation.

Trouble-shooting method: If the water chiller is used too long or not maintained regularly, some unexpected faults will inevitably occur. Here are some common troubleshooting methods.

8.1. Inverse phase

When the water-cooled refrigerator fails, it will be timely phase protection. The cause of the reverse phase is a reversal of pump and compressor.

At this time, we can switch any two phases in the power supply phase line. If the phase is absent, we only need to measure whether the three-phase power supply is normal with a multimeter to check whether the power supply line is broken.

8.2. The refrigerant is not enough and the indicator light is on

A. When the water temperature is above 5 °C, when the pressure of the low-pressure gauge is less than 2 kg/cm2, it means that the refrigerant is insufficient.

First, the place where the refrigerant is leaked is subjected to trapping treatment, and then the dry filter is replaced and the vacuum is refilled to fill the appropriate refrigerant.

B. When it is found that the leaking refrigerant is partially immersed in water, stop the operation of the water chiller immediately, remove the water in the water tank quickly, and handle the repair as soon as possible to prevent the compressor from inhaling water into the system and causing more serious damage.

8.3. Poor heat dissipation results in slow or non-refrigeration

When the condenser heat dissipation is poor, the compressor efficiency is low and the running current is increased. When the air-cooled high pressure rises to 24kg/cm2, the water-cooled high pressure rises to 20kg/cm2, and the compressor is subjected to high pressure.

The switch protection trips, the compressor stops running, the heat dissipation is poor, the high voltage is overloaded and the fault code or fault indication is displayed.

At this time, please check whether the cooling tower circulating the water is normal, whether the cooling water temperature is too high, whether the cooling tower fan water pump is running, and whether the cooling water valve is running.

The above is normal, press the reset button or shut down and restart to running normally. If high voltage overload occurs frequently, please arrange to clean the condenser as soon as possible.

8.4. Whether high and low pressure is normal

The second and third of the previous ones analyze in detail the pressure display of the compressor when the high pressure or the low pressure is abnormal.

Then when the compressor runs, the difference between high pressure and low pressure is small or equal, the compressor fails, then we should check whether the value of the compressor itself is damaged or broken, and immediately stop running and notify the supplier to send someone to deal with it.

If you have any question in troubleshooting，please contact us，we are very glad to help you solve those problems

Chapter 9: Maintenance of water chiller

During the normal operation of water chillers, it is unavoidable that dirt or other impurities affect the refrigeration effect.

Therefore, in order to prolong the service life of water-cooled chillers and make the refrigeration effect more stable, regular maintenance should be done to ensure the operation quality of water-cooled chillers and improve production efficiency.

Check regularly whether the voltage and current of water-cooled chillers are stable and the sound of a compressor is normal. If it is a semi-closed compressor, check regularly the oil quantity. Normally, it should be more than 2/3 of the window.

When the water-cooled chiller works normally, the voltage is 380V and the current is normal in the range of 11A-15A.

Regularly check whether the refrigerant of the water-cooled chiller has leakage: refer to the parameters indicated on the high and low-pressure gauges on the front panel of the main unit. According to the temperature (winter, summer) temperature changes, the chiller pressure display is also different.

When the chiller is working normally, the high pressure shows 11-17kg, and the low pressure shows 3.5kg-5kg.

Check whether the water cooling system of the water-cooled chiller is normal, whether the cooling tower fan and the sprinkler shaft are working well, and whether the water replenishment of the water tank of the water-cooled chiller is normal.

Water-cooled chillers should be replaced with new water for 3 months. If it cannot be replaced, add a rust remover.

All industrial chillers should be cleaned once every six months and cleaned once a year. The main cleaning parts include: cooling tower, cooling water pipe and condenser to ensure better cooling.

When water-cooled chillers are not used for a long time, circuit switches such as pumps, compressors and general power supply of cooling towers should be switched off in time.

Water-cooled chillers need to be connected with cooling towers and circulating pumps to achieve refrigeration effect. In order to ensure the quality of circulating water, Y-type filters can be installed at the source of water, and algaecide and scale remover can be added to the cooling towers to avoid impurities entering the pipeline affecting the operation of the unit.

Cleaning Method of Condenser Pipeline

Cut off the power switch.
Close the cooling water inlet and outlet ball valve.
Remove the front panel of the water-cooled chiller.
Remove the fixing screw and remove the round cover plate. Copper pipe can be seen. Please use a copper brush to clear it back and forth.

Conclusion

Whether you buy water chiller or plan to build a new plant, here is the right choice for you. We will provide you with the most suitable service.

We will unconditionally provide you with the most professional advice to help you choose the most suitable water chiller solution for your own,

Here is a variety of high-quality water chiller for your choice, and arrange professional technical personnel to train and install water chiller equipment, and provide free advice on troubleshooting to guide your technical personnel how to supervise and inspect water chiller equipment.

As the most professional water chiller supplier, you buy not only the selected equipment but also lifetime service for customers. As long as you want, we will become your partner to help you start your water chiller business.