Graduated from the University of Carabobo in Venezuela. (1996-2001).
Credential of the College of Engineers of Venezuela Number 131,187.
Specialist in the area of Industrial Refrigeration and HVAC Systems.
The use of reciprocating chillers is less common in high-efficiency systems. However, these compressors can still be found in new chillers, primarily designed for low thermal loads.
The operation of a piston compressor chiller is as follows:
The refrigerant, in its vapor state, is compressed by a piston inside a cylinder.
A thin layer of oil prevents the refrigerant vapor from escaping the compression chamber and serves to lubricate the system and reduce friction.
The piston is connected to the crankshaft via the piston rod.
As the crankshaft rotates, it causes the piston to move back and forth within the cylinder.
This reciprocating movement draws the refrigerant into the cylinder and compresses it.
The compressed refrigerant is then discharged to the chiller condenser.
The piston compressor is equipped with intake and discharge valves, which trap the refrigerant vapor inside the cylinder.
During the intake stroke, the intake valve is open, while during the compression stroke, both valves are closed.
As the pressure increases, the exhaust valve opens, allowing the refrigerant to escape.
For applications requiring less cooling, the chiller with a piston compressor can regulate its capacity.
This is achieved using a hot gas bypass valve located in the compressor discharge zone.
The hot gas is directed to the suction or inlet of the evaporator to simulate heat. However, the hot gas method does not offer energy efficiency advantages and can maintain acceptable refrigerant speed for oil return.
Most reciprocating compressors above 10 tons of refrigeration or 35 kW are equipped with cylinder unloaders to regulate their capacity.
Unloaders work by deactivating and activating the passage of refrigerant to the piston compressor’s compression chamber.
A solenoid valve controls the refrigerant flow, directing the pressurized compressor discharge refrigerant to the top to shut off and interrupt the refrigerant vapor flow to the cylinder suction.
Although the piston continues to move back and forth inside the cylinder, it no longer performs compression as it cannot absorb refrigerant vapor.
For comprehensive learning about chillers, we have prepared a complete training program on chilled water installations with chillers.
If you need a reliable and high-performance machine for cooling water flows, the rotary screw compressor chiller might be just what you’re looking for.
These machines are designed to operate using a compression refrigeration cycle, making them ideal for medium to high refrigeration power ranges. With cooling capacities ranging from 20 tons to 1,000 tons of refrigeration, there is a chiller available to suit your needs.
How do screw compressors work?
A screw compressor is a machine that increases the pressure of refrigerant gas that has been evaporated in the chiller. This high-pressure refrigerant is then sent to the condenser, where it is turned back into a liquid.
The screw compressor works by reducing its volume through the rotation of slotted helical screws within a tight tolerance housing.
The double rotor screw compressor is the most commonly used compressor in larger refrigeration installations, where the rotors rotate in opposite directions to draw gas into the rotors through an inlet port.
As the screws continue to turn, gas is trapped between the compressor housings and the rotors, and is released through an outlet port at a determined discharge pressure value.
What is the most common refrigerant used in screw chillers?
The most commonly used refrigerant in screw chillers is R-134A. However, due to environmental restrictions, newer refrigerants such as R513A have also been introduced.
Some screw chillers also use R410A, although this refrigerant has been replaced by more environmentally friendly options due to its high GWP value.
Which screw chiller is the best seller?
The best-selling chiller is the screw compressor with a water chiller in the range of 100 to 300 KW.
Popular Models of Screw Chillers:
Check out our table of the most commonly used models of screw chillers.
In this table, we have models of Screw Chillers and their main characteristics:
Chiller Model
Chiller Gas
Cooling Capacity
Cooling of Condenser
AquaForce 30XA
Carrier R134a
80 – 500 TR
Air-Cooled
AquaForce 30XV
Carrier R-134a
490 – 1755 TR
Air-Cooled
AquaForce 30HX
Carrier R-134a
75 – 265 TR
Water-Cooled
AquaEdge 23XRV
Carrier R-134a
175 – 550 TR
Water-Cooled
AquaForce 30XW
Carrier R-134a
150 – 400 TR
Water-Cooled
York YVAA
R-410A
150 – 575 TR
Air-Cooled
York YVFA
R-410A
150 – 500 TR
Air-Cooled
York YCIV
R-410A
150 – 400 TR
Air-Cooled
Trane RTAE
R134a
150 – 300 TR
Air-Cooled
Trane RTAC
R-134a
140 – 500 TR
Air-Cooled
Daikin Pathfinder
R-134a
100 – 565 TR
Air-Cooled
Daikin Navigator
R-134a
120 – 300 TR
Air-Cooled
Where to learn all about chillers?
We have prepared a complete training in chilled water installations with chillers.
The Propane Chiller is a machine that works with a compression refrigeration circuit, designed for water cooling, used in air conditioning applications or equipment cooling.
Features of the propane Chillers:
Compressors in propane chillers are generally of the reciprocating or screw type.
Some compressors that work with R290, use the same polyester oils as the compressors with R134a.
R290 has a high solubility with mineral oil and polyester oil. The Condenser is usually air cooled, and works with copper tubes and aluminum fins.
The high pressure side of the propane chiller must withstand a minimum of 3.5 times the saturation pressure of propane at 70 ° C, that is, 87 bar.
The low pressure side of the propane chiller must withstand 5 times the saturation pressure of propane at 20 ° C, ie 36.8 bar.
Before installing the propane chiller, it is particularly important that a risk assessment is carried out, with respect to the intended position of the chillers.
The propane chiller must have a leak detection and control system, which when activated, will carry the propane charge to a liquid receiver, and then will cut off the electrical supply to the cooler.
The propane chiller has refrigerant release valves, in case of continuing overpressures.
In a propane chiller, when abnormally high pressure is present, as a first option the R290 gas should be released to the low pressure side of the system, rather than released to the atmosphere.
The propane chiller release valves must be installed at the highest point of each circuit of the capacitor bank.
Propane chiller release valves must be easily accessible and clearly visible from a safe distance, thus alerting operators to the possible release of a flammable gas.
If the pressure continues to increase, then the gas is released through a pressure relief valve; Each propane chiller refrigeration circuit must be equipped with a properly selected relief valve to release excess pressure.
The valve must be mounted above the high pressure liquid receivers.
Whenever possible, the discharge port on the valve should be directed to a safe location, away from any source of ignition, preferably in an upward direction, to avoid low-level propane build-up.
In a propane chiller, periodic leak checks are particularly important.
Four quarterly inspections are recommended each year, and record keeping should be carried out in accordance with regulations.
Propane chillers can be used to generate ice water or brine, in air conditioning, process refrigeration, and commercial refrigeration applications.
The refrigerant charge of a propane chiller can be 40 to 60% lower than other refrigerants.
Propane chiller motor winding thermistors must be housed and wired separately from other electrical components.
There is no mandatory limit on the amount of propane that can be used in an outdoor chiller.
However, some manufacturers have adopted 25 kg as the upper limit for the amount of propane per circuit
What is the working pressure in the R290 chiller?
Temperature °C
Pressure psig
-20°C
35.8 psig
-18°C
38.6 psig
-16°C
41.6 psig
-14°C
44.4 psig
-12°C
47.5 psig
-10°C
50.7 psig
-8°C
54.24 psig
-6°C
57.8 psig
-4°C
61.6 psig
-2°C
65.6 psig
0°C
69.7 psig
2°C
74. psig
4°C
78.6 psig
6°C
83.4 psig
8°C
88.3 psig
10°C
93.5 psig
12°C
98.9 psig
14°C
104.7 psig
16°C
110.5 psig
18°C
116.6 psig
20°C
122.9 psig
22°C
129.5 psig
24°C
136.4 psig
Pressure vs Temperature R290
Where to learn all about chillers?
We have prepared a complete training in chilled water installations with chillers.
The scroll compressor chiller is a widely used cooling system in low-capacity applications.
This chiller operates on a compression refrigeration circuit and is suitable for low to medium thermal loads. It can be equipped with either an air-cooled or water-cooled condenser.
Each individual scroll compressor typically handles refrigeration capacities of less than 25 tons. To achieve higher cooling power, multiple scroll compressors can be used in parallel.
Scroll compressors boast high efficiency, and when combined with inverter technology, they can further optimize the efficiency of the chilled water plant.
The design of parallel scroll compressors requires meticulous lubrication control, which is ideally automated for ease of operation.
Characteristics of scroll chillers include a hermetic squirrel cage induction motor, cooled by suction gas, contributing to its longevity and stability. The elimination of suction valves in scroll compressors reduces valve losses and enhances efficiency.
By utilizing multiple scroll compressors, the chiller’s capacity can be adjusted according to the plant’s demand, offering a degree of redundancy in case of compressor failure.
However, the presence of more compressors may slightly increase the probability of failures, but the overall reliability of scroll compressors due to their few moving parts mitigates this concern.
Inverter-type scroll compressor chillers enable adaptability to varying cold needs within the plant, improving overall efficiency.
To maximize the chiller’s performance, an oil equalization system must be implemented to ensure consistent and reliable operation.
Chillers with scroll compressors are available in various refrigerants, including R22, R407C, R134a, R404A, and R410A.
For comprehensive learning on chilled water installations and chillers, we offer a complete training program.
Introducing the Chiller Tonnage Calculator: Your Handy Tool for Efficient Cooling
Are you looking for a way to accurately calculate the thermal load and water flow required for your chiller system? Look no further than our Chiller Tonnage Calculator!
Designed specifically for industrial processes and machine cooling applications, our calculator can help you determine the total chilled water flow your plant needs, the minimum water temperature required at the chiller outlet, and the outlet temperature at the chiller inlet.
Armed with this information, you can make informed decisions and accurate quotes before making any purchases.
Our user-friendly form makes it easy to input the necessary values for chiller calculation. Whether you need to determine pipe sizing, water flow rates, or glycol chiller sizing, our calculator has got you covered.
But what if you prefer to do things manually? No problem! Our calculator also provides the formula you need to manually calculate chiller tonnage.
With the Chiller Tonnage Calculator, you can ensure that your chiller system is properly sized for your application, leading to more efficient and effective cooling. Try it out today and see the difference it can make for your industrial processes!
Chiller Tonnage calculation formula:
For manual calculation the following information is required:
Specific Heat Table of Water:
Kcal/Kg°C
J/Kg°C
Btu/lb°F
Specific Heat of Water
1
4186
1
NOTE: The specific heat of the water indicates the amount of heat that needs to be extracted from the water to decrease the temperature by one degree.
Water Density Table:
Kg/L
Kg/m3
Lb/ft3
Water density
1
1000
62.43
NOTE: The density of the water allows us to transform the volumetric flow into the mass flow.
Heat Power Units Conversion Table:
Heat Power Unit
Equals
Equals
Equals
1W
0.86 Kcal/h
3.41 Btu/h
0.00028435 TRF
1 Btu/h
0.25 Kcal/h
0.29 W
0.00008333 TRF
1 Kcal/h
3.96 Btu/h
1.16 W
0.00033069 TRF
1 TRF
12000 Btu/h
3516.85 W
3023.95 Kcal/h
Note: The table shows the common units for measuring heat output in the refrigeration sector.
Volume Flow Conversion Table:
Volumetric Flow
Equals
Equals
Equals
1 m3/s
0.01 ft3/s
16.67 L/min
4.4 GPM
1 L/min
0.26 GPM
0.000589 ft3/s
0.06 m3/s
1 ft3/s
101.94m3/h
1699 L/min
448.83 GPM
1 GPM
0.23 m3/h
3.8 L/min
0.000589 ft3/s
Chiller Calculation International System of Units:
Chiller Calculation made easy with the International System of Units!
So you need to calculate the power required for your chiller? No problem! Here’s what you’ll need to get started:
Maximum water flow = 18 m3/h Chiller water inlet temperature = 14°C Chiller water outlet temperature = 8°C
Step One: First things first, we need to calculate the change in temperature of the water inside the chiller. Easy peasy!
T water inlet – T water outlet = 14°C – 8°C = 6°C Temperature change = 6°C
Step Two: Next, we’ll use the specific heat to determine the amount of heat required to achieve the desired temperature change.
Specific heat is the amount of heat required to raise the temperature of 1 kg of water by 1°C. In this case, our specific heat is 1 kcal/kg°C.
Total heat to be extracted = Specific heat x Temperature change Total heat to be extracted = 1 kcal/kg°C x 6°C = 6 kcal/kg (that’s 6 kcal for each kg of water that enters the chiller)
Step Three: Now it’s time to calculate the power. We’ll need to know the mass flow that the chiller will receive.
Chiller water flow = 18 m3/h
Using table 4, we have: 18 m3/h x 16.67 = 300 liters/minute = 5 liters/second
Mass flow = Volumetric flow x Density Mass flow = 0.5 l/s x 1 kg/l = 5 kg/s
Chiller power = Total heat x Mass flow Chiller power = 6 kcal/kg x 5 kg/s = 30 kcal/s
Step Four: The final result needs to be converted to units of heat for use in refrigeration.
We’ll convert 30 kcal/s to kcal/h by multiplying by 3600.
30 kcal/s x 3600 = 108000 kcal/h
This value can be converted to different units:
108000 x 3.96 = 427680 Btu/h 108000 x 1.16 = 125280 W 108000 x 0.00033069 = 35.7 TRF (Tons of Refrigeration)
Step Five: To be on the safe side, we recommend applying a safety factor of 20%. This compensates for losses due to insulation deficiencies.
Chiller power = 35.7 TRF x 1.2 = 42.84 TRF
And there you have it, your chiller power calculation is complete!
Where to learn all about chillers?
We have prepared a complete training in chilled water installations with chillers.
Air-cooled packaged chillers are typically available in capacities between 8 to 550 tons of refrigeration, while water-cooled packaged chillers are typically available in 10 to 5,000 tons.
In the following table we have a comparison between the initial investment for each chiller, according to the condenser cooling:
Investment initial chiller
150 TRF
300 TRF
450 TRF
600 TRF
750 TRF
Cooled by air
100%
100%
100%
100%
100%
Cooled by water
150%
140%
130%
120%
95%
This means that the condenser, compressor, and evaporator are included within the machine and are designed and configured from the factory for optimum performance and reliability, reducing design and lead time and simplifying installation.
Water-cooled condenser chillers have the added complexity of condenser piping, pumps, cooling towers, and water controls, and their performance is highly installation-dependent.
Most air-cooled condenser chillers are “packaged systems”.
This means that the condenser, compressor, and evaporator are included within the machine and are designed and configured from the factory for optimum performance and reliability, reducing design and lead time and simplifying installation.
Water-cooled condenser chillers have the added complexity of condenser piping, pumps, cooling towers, and water controls, and their performance is highly installation-dependent.
Liquid Cooling vs Air Cooling Electric Power Costs:
Water-cooled chillers and refrigeration systems are generally more energy efficient than air-cooled ones.
Since the wet bulb temperature is often significantly lower than the dry bulb temperature, the condensation temperature and pressure of the refrigerant in a water-cooled refrigeration system can be lower than in an air-cooled cycle.
This means that the compressor needs to do less work and therefore consumes less energy.
This efficiency advantage may decrease during a night operation because the dry bulb temperature tends to drop faster than the wet bulb temperature when the sun sets.
Where to learn all about chillers?
We have prepared a complete training in chilled water installations with chillers.
Are you ready to chill with the Industrial Water Chiller System ? These liquid chillers are designed to cool machinery and processes with special temperature requirements.
But wait, what temperatures are we talking about here?
Let’s break it down. The Industrial Refrigeration Chiller can be classified according to the temperature range they handle.
We’ve got the Conventional Industrial Refrigeration Chiller for temperatures above 35°F.
Industrial Refrigeration Chiller for medium-low temperatures for values between 20°F and 35°F.
Low-Temperature Industrial Refrigeration Chiller generally between 20°F and -59°F.
Ultra-Low Temperature Industrial Refrigeration Chiller for ranges between -60°F and -112°F.
Why do we need Industrial Chillers for Special Refrigeration, you ask?
Well, some processes require an outlet fluid temperature below 35°F. For this, we use industrial chiller systems with multiple cooling stages that can reach even lower temperatures by using a mixture of water and glycol. Some chillers even use different fluids for each cycle to meet temperature demands.
When it comes to low-temperature industrial chillers, the oil management system must consider all necessary measures to guarantee the oil returns to the compressor, even at low viscosity levels. And, let’s not forget about the interior components of the ultra-low temperature industrial chiller, which need to be more efficient, stronger, and durable.
While industrial air-cooled chillers are great for most applications, they are not recommended when an outlet fluid temperature below -30°F is needed.
For this, we use two- and three-stage coolers that can use a variety of heat transfer fluids containing silicone oils, inert fluorinated fluids, hydrofluoroethers, or alkylated aromatic fluids. Some chillers even work with the environmentally friendly R507 Refrigerant Gas.
When it comes to capacity, low-capacity industrial chillers use a scroll-type compressor, while low-temperature industrial screw chillers are ideal for quick freezing of food and prepared meals in the food industry.
So, there you have it, the Industrial Water Chiller System is here to chill with special temperature requirements.
Where to learn all about chillers?
We have prepared a complete training in chilled water installations with chillers.
