What is a Water Chiller?

In the refrigeration industry, it is divided into air-cooled chiller and water-cooled chiller. According to the compressor, it is divided into screw-type chiller and scroll-type chiller. The temperature control is divided into low-temperature industrial chiller and normal-temperature chiller. , Normal temperature unit temperature is generally controlled in the range of 0 degrees -35 degrees. Low temperature unit temperature control is generally between 0 degrees and -100 degrees.

Chiller

In the refrigeration industry, it is divided into air-cooled chiller and water-cooled chiller. According to the compressor, it is divided into screw-type chiller and scroll-type chiller. The temperature control is divided into low-temperature industrial chiller and normal-temperature chiller. , Normal temperature unit temperature is generally controlled in the range of 0 degrees -35 degrees. Low temperature unit temperature control is generally between 0 degrees and -100 degrees.

The chiller is also known as:

The chiller includes four main components: compressor, evaporator, condenser, and expansion valve, thus achieving the cooling and heating effect of the unit.

Chillers are commonly known as freezers, freezers, ice water freezers, freezers, coolers, etc., because they are widely used in various industries, their names are innumerable. With the continuous development of the chiller industry, more and more people are beginning to pay attention to any choice of the chiller industry. It is more and more important for human beings. In terms of product structure, "high energy efficiency water-cooled screw units", "water source heat pump units", " "Screw-type heat recovery unit", "High-efficiency heat pump unit", "Screw-type low-temperature refrigeration unit" and other highly competitive product structures. Its principle is a multifunctional machine that removes liquid vapor through compression or heat absorption. Refrigeration cycle. The steam compression chiller includes four main components: compressor, evaporator, condenser, and some metering devices. Different refrigerants are realized through the form of a vapor compression refrigeration cycle. Absorption chiller uses water as a refrigerant and relies on the water and lithium bromide solution to achieve a strong affinity for refrigeration effect. Chillers are generally used in air-conditioning units and industrial cooling. In air conditioning systems, chilled water is usually distributed to heat exchangers or coils.

The performance form of chiller can be roughly divided into two types

Air-cooled chiller-Features

1. Free installation of cooling tower, easy to install and convenient to move, suitable for occasions without water tower without installation of water source.

2. Low-noise fan motor, excellent cooling and condensation effect, stable throttling mechanism, and excellent anti-rust treatment.

3.Using European and American high-performance compressors, high EER value, low noise and stable operation.

Water-Cooled Chillers-Features

1.Ergonomic panel, fully automatic control, equipped with precision electric temperature controller, can run smoothly for a long time.

2. Adopting high-efficiency heat transfer heat exchanger, which has the advantages of less cooling loss and easy oil return, and the heat transfer tube will not cause frost cracking.

3. Japan-US imported high-performance compressor, high EER value, low noise and stable operation.

Figure 1-Flow diagram of air-cooled chiller

Air-cooled Screw Chiller-Features

1. The air-cooled condenser is a fin type, which adopts double oil ripple hydrophilic aluminum-platinum. It is manufactured by professional heat exchanger processing equipment. Low speed large leaf axial flow fan can effectively reduce the operating noise and reduce the impact on the surrounding environment.

2. The unit control system adopts imported PLC program controller. The human-machine world is equipped with a large screen touch screen. The interface is simple and elegant, and the operation is intuitive and simple.

3. The unit has reliable safety protection devices, including: high and low voltage protector, exhaust overheat protector, compressor motor overheat protector, overload current protector, antifreeze temperature protector, water flow protector, emergency stop switch, temperature sensing Fusible plugs, safety valves, etc.

Water-cooled screw unit-features

1.Simple structure, stable heat exchange, long lasting efficiency, convenient maintenance

2. The unit control system adopts imported PLC program controller, and the man-machine interface is equipped with a large screen touch screen. The interface is simple and elegant, and the operation is intuitive and simple.

Air-cooled low temperature chiller-Features

Low-temperature chiller is a special chiller designed for special low-temperature environments. Its super cooling capacity is used for food preservation in hotels, restaurants, supermarkets and other commercial places. Food processing freezing / refrigeration, pharmaceutical, chemical and other low temperature environments provide reliable protection.

1. Complete product range, including three series of high temperature (water temperature -5 ), medium temperature (water temperature -10 ), low temperature (water temperature -15 ).

2. The structure is highly optimized. The heat exchanger plate is used to support the body. The structure is simple, compact and practical.

3. A perfect combination of high-quality screw compressors and the highest quality and high-efficiency heat exchangers, with an energy efficiency ratio of up to 4.5.

4. Four-stage or stepless capacity control to precisely match load changes.

Water-cooled low temperature chiller-Features

Water-cooled chiller is small in size and large in cooling capacity. It adopts world-famous imported compressors with excellent low-temperature performance, reliability and durability. The product is designed according to industrial application characteristics. It has a built-in low-temperature circulating water pump and a stainless steel freezing water tank. The materials are anti-corrosive materials, which effectively prevent rust and corrosion. The microcomputer LED quantity controller has temperature display, set temperature, automatic adjustment of frozen water temperature and compressor delay protection function. Select brand-name contactors, relays and other electrical components , Equipped with perfect indicator lights, switches, and clear operation, built-in electronic water level indicator and alarm device, automatic alarm for low water level, the operator can grasp the water level of the chilled water tank through the control panel, and replenish water in time. The unique modular design, each The system of each compressor is safe and independent, and even if a problem occurs in one system, it will not affect the normal operation of other systems.
1. The compressors of the unit are medium and low temperature compressors, such as the original imported brands of Maneurop (French), American Copeland / Carrier, and German BITZER;
2. Use refrigerants such as R404A, R410a, R22 / R407C, etc., to meet the requirements of refrigeration temperature and environmental protection;
3. Temperature selection range: process frozen water between -5 ° C and -60 ° C can be provided (users can choose unit specifications with different outlet temperatures according to different production needs;
4. According to the needs of users, a variety of refrigerants (chilled water) can be selected: glycol refrigerants, alcohols, ternary mixed solutions and other alcoholic refrigerants. The evaporator can also be designed according to anticorrosion requirements and chlorinated. Aqueous calcium solution

Water source heat pump hot water unit-features

1. The unit design is reasonable, the structure is compact, the appearance is beautiful, the volume is small, and the floor space is small;

2. Energy saving and environmental protection, while providing customers with industrial cold water, it can also supply a large amount of free sanitary hot water. The cooling of the thermal system is increased, the energy utilization rate is high, and the recovered heat can reach 30-80% of the cooling capacity;

3. Low operating costs, improve unit efficiency, improve working conditions, and save unit operating costs;

4. It is safe and reliable, and the temperature and temperature are relatively constant, making the heat pump unit more reliable and stable, ensuring the efficiency and economy of the system, and no special maintenance or operation is required, and the operation and maintenance costs are minimal;

5. Reliable: stable performance, low noise, long service life, thermal factor collection technology reduces unit load and reduces failure rate.

6. Intelligent control, fully automatic microcomputer control, without manual monitoring, can realize remote or centralized management

Air-cooled heat pump unit-features

1. High efficiency and energy saving, with a comprehensive energy efficiency ratio of up to 8.0, which can provide cooling, heating, and domestic hot water operating conditions according to the ambient temperature and hot water demand.

2. The investment is profitable, and the cold quantity is recovered during hot water production, which can achieve zero cost of refrigeration.

3. Safety and environmental protection, using refrigerant as the medium, non-toxic, non-explosive, can be connected to the original hot water system, can also replace the high-risk, high-cost boiler system, can also be used in conjunction with solar energy systems, instead of electric heating.

4. Fully automatic computer control, no special person monitoring required, can be operated through remote or centralized management system.

5. Unit or modular, assembled structure, slim size, can be flexibly installed on the roof, terrace or machine room, etc.

Chillers for air conditioners

One: Industrial Air Cooler-Features

Industrial air cooler is designed for the cooling process of aluminum-free wave soldering, reflow soldering and other equipment. According to the temperature control temperature, the specifications are divided as follows: 10 degrees or more, 5-10 degrees, 0-5 degrees, -5--15 degrees.

2: Central Air Conditioning-Features

The water-cooled cabinet air conditioner is a new type of central air-conditioning unit. It concentrates the essence of domestic and foreign products. It is manufactured using modern advanced technology. It has excellent quality and beautiful appearance. specification

Central air-conditioning host:

1. Water-cooled chiller adopts horizontal shell-and-tube condenser and shell-and-tube evaporator. It has the characteristics of simple structure, stable heat exchange, long-lasting efficiency, and convenient maintenance. composition.

2. The unit control system adopts imported plc controller, and the man-machine interface is equipped with a large screen touch screen. The interface is simple and elegant, and the operation is intuitive and simple.

3. The unit has reliable safety protection devices, including high and low voltage protectors, exhaust overheat protectors, compressor motor overheat protectors, overload current protectors, antifreeze temperature protectors, water flow protector emergency stop switches, and easy temperature sensing. Fuses, safety valves, etc.

The start and stop sequence of the chiller must ensure the normal operation of the air-conditioning main unit after startup, and must ensure that:

The condenser dissipates heat well, otherwise the cold-condensation temperature and the corresponding condensing pressure will be too high, which will cause the high-pressure protection device of the chiller to stop and even cause failure.

The cold water in the evaporator should be circulated. Otherwise, the cold water temperature will cause the cold water temperature protection device to operate and stop, or the evaporation temperature and the corresponding evaporation pressure will be too low. This will cause the cold water in the evaporator to freeze and damage the equipment. Therefore, the chiller's startup sequence is: (must be strictly observed) Cooling tower fan on-> cooling water pump on-> cold water pump on-> chiller on The chiller shutdown sequence is: (must be strictly followed) Stop-> Cooling Tower Fan Stop-> Cooling Water Pump Stop-> Cold Water Pump Stop

How to choose the most suitable industrial chiller for you? In fact, there is a simple selection formula:

Cooling capacity = chilled water flow * 4.187 * temperature difference * coefficient

1. Frozen water flow refers to the cold water flow required for the machine to work, and the unit needs to be converted into liters / second;

2. Temperature difference refers to the temperature difference between the water entering and leaving the machine;

3.4.187 is quantitative (specific heat capacity of water);

4. When selecting air-cooled chiller, the multiplication factor is 1.3. When selecting water-cooled chiller, the multiplication factor is 1.1.

5. Select the corresponding machine model based on the calculated cooling capacity.

The general habit is to use P to calculate how big the chiller is, but the most important thing is to know the rated cooling capacity. If the general air-cooled 9.07KW looks like a 3P machine, and so on. So the most important choice of industrial chiller is to find the rated cooling capacity

1. The evaporation pressure is too low:

the reason:

(1) The amount of cold water is insufficient.

(2) Less cooling load.

(3) The orifice plate is malfunctioning (only the evaporation pressure is low).

(4) The heat transfer tube of the evaporator deteriorates the heat transfer due to pollution such as scale (only the evaporation pressure is too low).

(5) The amount of refrigerant is insufficient (only the evaporation pressure is too low).

Solution:

(1) Check the cold water circuit so that the amount of cold water reaches the rated water volume.

(2) Check the setting temperature of the automatic start-stop device.

(3) Check whether the expansion throttle tube is unblocked.

(4) Clean the heat transfer tube.

(5) Replenish the refrigerant to the required amount.

2. Condensing pressure is too high:

the reason:

(1) The amount of cold water is insufficient.

(2) The capacity of the cooling tower is reduced.

(3) The cold water temperature is too high and the cooling capacity is too large, which increases the condenser load.

(4) The presence of air.

(5) The heat transfer of the condenser tube is deteriorated due to scale pollution.

Approach:

(1) Check the cooling water circuit and adjust to the rated flow.

(2) Check the cooling tower.

(3) Check the expansion throttle, etc., so that the temperature of the cold water approaches the rated temperature as soon as possible.

(4) Exhaust air to exhaust air. If the exhaust device needs to be operated frequently, you must find out where the air leaks in and eliminate it.

(5) Clean the tube.

3. The oil pressure difference is too low:

the reason:

(1) The oil filter is clogged.

(2) The opening degree of the oil pressure regulating valve (drain valve) is too large.

(3) The output of the oil pump is reduced.

(4) Bearing wear.

(5) The oil pressure gauge (or sensor) fails.

(6) Too much refrigerant is mixed in the lubricating oil (the oil pressure is too low due to oil foaming at startup).

Approach:

(1) Replace the oil filter element.

(2) Close the small oil pressure regulating valve to increase the oil pressure to the rated oil pressure.

(3) Disintegration inspection.

(4) Replace the bearing after disassembly.

(5) Check the oil pressure gauge, recalibrate the pressure sensor, and replace if necessary.

(6) After stopping the refrigerator, be sure to turn on the oil heater to maintain the given oil temperature (confirm whether the oil heater is disconnected and whether the setting value of the oil heater temperature control is correct).

4. Oil temperature is too high:

the reason:

(1) The cooling capacity of the oil cooler is reduced.

(2) The supply amount of the refrigerant for cooling the oil cooler is insufficient due to the clogging of the refrigerant filter screen.

(3) Bearing wear.

Approach:

(1) Adjust the oil temperature control valve.

(2) Clean the refrigerant filter screen.

(3) Repair or replace bearings after disassembly.

5. Overload of main motor:

the reason:

(1) The phase voltage of the power supply is unbalanced.

(2) The voltage drop of the power line is large.

(3) The amount of cooling refrigerant supplied to the main motor is insufficient.

Approach:

(1) Take measures to balance the power supply phase voltage.

(2) Take measures to reduce the voltage drop of the power line.

(3) Check the filter of the refrigerant filter and clean the filter; open the refrigerant inlet valve

With the rapid development of the economy and the continuous improvement of scientific and technological strength, our chiller manufacturing technology is also changing with each passing day, and the gap with developed countries is gradually narrowing, but the main core components such as compressors are still mostly foreign or joint venture compressors. It has also inadvertently increased corporate costs.

In modern society, the application of refrigeration equipment is becoming more and more extensive. Modern refrigeration devices are all cooled by chiller. The market prospect of chiller is promising. Countries with advanced chiller technology are still some developed countries in the West. Their development trends are also based on the actual situation in their country, vigorously improve the shape of the chiller, continuously improve the performance of the chiller, and achieve the effect of reducing the volume of the chiller and increasing its efficiency.

Experts point out that with the increasingly fierce market competition and gradually matured chiller development technology, miniaturized, high-efficiency chiller has become a new trend. At the same time, in order to adapt to the rapid development of industrial production, more personalized and more practical products will continue to emerge.

GB10870-2001 "Performance test methods for volumetric and centrifugal chilled water (heat pump) units"

GB19577-2015 "Limited Energy Efficiency Values and Energy Efficiency Ratings for Chillers"

JB8654-1997 "Safety requirements for volumetric and centrifugal chilled water (heat pump) units"

First, adjust the operating load ratio

The different load ratios of chiller units have an inevitable relationship to energy consumption. During daily chiller operation, 70% to 80% of the load operation energy consumption is far lower than 100% of the load operation, so the specific requirements of the unit are used in combination. In the given time, the purpose of reducing energy consumption can be achieved by reducing the load ratio of the chiller. As long as the unit cooling power consumption is at a lower level, the energy consumption at this time is greatly reduced.

Second, increase evaporation temperature

In actual use, as long as the chiller evaporation temperature and the condensation temperature are effectively increased, the purpose of improving energy efficiency can be achieved, especially for chiller equipment equipped with a cooling water tower. Using such methods can greatly improve the cooling water tower. The efficiency of the cooling water source reduces the problem of energy loss. According to the introduction of domestic refrigerator manufacturers, increasing the evaporation temperature and reducing the condensation temperature are the most common methods to reduce power loss.

Third, reduce pipeline blocking

If the pipeline is blocked, it will seriously affect the increase of water flow and lead to the increase of energy consumption. In actual use, keeping the pipeline in a clear state by different methods can greatly reduce the excessive consumption of various types of energy. To achieve the purpose of improving the working efficiency of chiller. ^[1]