Category: Chiller Information

Types of chilled water pumps

Chilled water pumps play a vital role in various applications, making them essential components in HVAC systems. Here’s an in-depth exploration of their functions and operations:

  1. Chilled Water Delivery: These pumps efficiently deliver chilled water to machines that require continuous cooling, ensuring optimal performance and reliability.
  2. Air Handling Units and Fan Coils: Chilled water pumps are employed to send chilled water to air handling units and fan coils, regulating indoor temperature with precision.
  3. Condenser Cooling: Pumps circulate water to cool the condenser in refrigeration circuits, maintaining optimal heat exchange.
  4. Special Cold Rooms and Industrial Processes: Chilled water pumps effectively cool special cold rooms and cater to cooling requirements in diverse industrial processes like ice rinks.
  5. Liquid Refrigerant Pumps: In refrigeration systems with flooded evaporators, these pumps, constructed from stainless steel, ensure seamless compatibility with the fluid.
  6. Well Pumps: Well pumps are used to replenish evaporated water in cooling towers, ensuring proper water levels for efficient cooling.
  7. Positive Displacement Pump for Oil: These pumps facilitate lubrication of components like compressors and feed hydraulic systems, ensuring smooth operation.

Centrifugal Pump Operation: Unveiling the Mechanism

Centrifugal pumps, pivotal in chiller systems, follow a sophisticated operational process:

  • The pump receives fluid in a liquid state through its center.
  • The impeller, or pump wheel, rotates due to the motor’s rotation, generating centrifugal forces.
  • Centrifugal force propels the liquid from the center of the wheel to its outer end.
  • The impeller’s curved shape allows the fluid to stay longer, resulting in higher speed.
  • The fluid gains kinetic energy, which must be converted into pressure.
  • Energy transformation occurs as the fluid passes through a nozzle, gradually reducing its speed while increasing the area of passage.
  • This conversion leads to the gradual transformation of kinetic energy into pressure.
  • The fluid exits the pump casing with high pressure, ready for its designated cooling tasks.

Essential Tips for Optimal Pump Performance

Understanding crucial pump care and maintenance is vital for HVAC system efficiency:

  • Never start the pump without sufficient water to prevent damage to seals and bearings.
  • Ensure proper priming to fill the suction pipe with water for seamless operation.
  • Prevent cavitation, which can damage the pump, by maintaining sufficient pressure in the suction and avoiding obstructions in the pipeline.
  • Always use motors with matching speeds and power to ensure smooth functioning.
  • Precise alignment of pump components, such as motors and shafts, is critical to prevent bearing damage.
  • Install necessary accessories, like valves and filters, to optimize pump operation.

Water Hammer and How to Avoid It

Water hammer, sudden pressure fluctuations when closing valves or turning the pump on and off abruptly, can lead to equipment damage. Soft starters with progressive start and stop mechanisms help avoid water hammer, preserving the system’s integrity.

Condensation Water Circuit and Primary Pump Circuit

Discover the functions of cooling towers, condenser water pumps, and water treatment systems in water-cooled condensers, efficiently dissipating heat from chillers.

The primary pump circuit plays a crucial role in circulating water through chillers to achieve optimal fluid conditioning. Its proper maintenance ensures optimal performance and flow through the chiller components.

Secondary Pump Circuit: Enhancing Distribution

The secondary pump circuit drives frozen water to different distribution systems like fan coils and air management units, overcoming frictional resistance in the network. The hydraulic decoupler acts as a balance line, ensuring stable pump operation and preventing operational issues.

Explore the various chilled water plant installations and their specific pumping schemes for increased efficiency and energy conservation.

Join us in this comprehensive guide to chilled water pumps, and empower yourself with knowledge for effective HVAC system management. Optimize pump performance and enhance your HVAC system’s overall efficiency today!

Chiller Refrigerant Subcooling

Chiller Refrigerant Subcooling is a critical parameter in engineering that measures the temperature difference between the liquid refrigerant at the chiller condenser outlet and the gas condensation temperature. This differential can be calculated using the following formula:

Subcooling = Refrigerant outlet temperature – Condensing temperature.

Conversely, the outlet temperature can be determined by subtracting the subcooling value from the condensing temperature:

Outlet temperature = Condensing temperature – Subcooling.

Let’s delve into the calculation of air-cooled refrigerant subcooling for a comprehensive understanding. Consider a chiller operating under ideal conditions with a subcooling value of 3°C in an ambient environment of 30°C. Typically, the condensing temperature of a refrigerant ranges from 10°C to 20°C above the ambient temperature. For this example, we will assume an average condensing temperature of 15°C.

Given an ambient temperature of 30°C, the condensing temperature can be calculated as follows:

Condensing temperature = Ambient temperature + 15°C Condensing temperature = 35°C + 15°C = 50°C.

To determine the refrigerant’s outlet temperature at the chiller condenser, we use the following formula:

Outlet temperature = Condensing temperature + Subcooling Outlet temperature = 50°C – 3°C = 47°C.

Refrigerant subcooling plays a vital role in chiller systems, as it significantly impacts their performance and energy efficiency. Greater subcooling indicates that the refrigerant remains further away from the vapor phase as it reaches the condenser outlet. This enhanced subcooling directly correlates with better condenser operation, potentially leading to lower chiller high pressures and reduced electrical energy consumption.

Moreover, subcooling affects the percentage of refrigerant that evaporates in the expansion valve, where a sudden pressure drop occurs. It is important to note that higher subcooling levels result in a reduced amount of refrigerant evaporating as flash steam during this process. By minimizing evaporation in the expansion valve, system efficiency improves, as the liquid refrigerant is primarily responsible for heat absorption in the chiller’s evaporator. Lower refrigerant evaporation also results in reduced overheating, further enhancing the chiller’s overall energy efficiency.

To optimize Chiller Refrigerant Subcooling, it is crucial to follow these best practices:

  1. Regularly clean air-cooled condenser coils to maintain optimal performance.
  2. Ensure proper airflow from the condenser cooling fans by conducting regular checks.
  3. Implement suitable maintenance procedures for the cooling tower water circuit in air-cooled condensers to prevent fouling and contamination, which can hinder condenser heat exchange and cooling efficiency.
  4. Maintain the correct airflow rate and ensure the cooling tower is in good condition for air-cooled condensers.

By adhering to these practices, you can enhance Chiller Refrigerant Subcooling, leading to improved chiller performance, energy efficiency, and ultimately, a more sustainable operation.

Optimizing Refrigeration Performance with Mollier Diagram: Subcooling Insights

The Mollier diagram is crucial in refrigeration engineering, providing valuable insights into subcooling processes for optimizing system performance. Engineers can precisely determine the ideal subcooling requirements, ensuring efficient heat transfer and preventing undesired vaporization. By leveraging the Mollier diagram, subcooling levels can be fine-tuned for specific operating conditions, enhancing overall efficiency and minimizing risks. Explore our comprehensive video explanation for a deeper understanding of the Mollier diagram’s practical applications in refrigeration systems.

Chiller Refrigerant Superheat

Chiller Refrigerant Superheat: A Guide to Understanding and Calculating

When it comes to chiller operation, there’s one important factor you don’t want to overlook: superheat. But what exactly is superheat? Put simply, it’s the difference between the evaporation temperature of the refrigerant gas in the chiller evaporator and the temperature at the compressor inlet.

https://youtu.be/wGfbexzhn38

To calculate superheat, you can use this equation:

Superheat = Evaporator outlet temperature – Compressor inlet temperature

Let’s take a closer look at two different types of chiller evaporators and how to calculate their superheat.

Dry Chiller Evaporator:

If you’re using a chiller with a thermostatic expansion valve for air conditioning, you’ll want to know the evaporation temperature, which is typically around 7°C. The temperature at the evaporator outlet (compressor inlet) will depend on the cooling load and valve setting, but let’s say it’s around 11°C.

Using the superheat equation, we can calculate:

Superheat = Evaporator outlet temperature – Compressor inlet temperature Superheat = 11°C – 7°C = 4°C

Chiller Flooded Evaporator:

In this type of evaporator, the liquid refrigerant from the refrigeration circuit is fed through a float valve to maintain a constant level inside the casing. As the cooling load varies, a refrigerant level control valve ensures that the liquid level is maintained in the shell. The outlet of the refrigerant from the evaporator is located at the top, and is always above the level, so the refrigerant must be in a vapor state to rise and reach the outlet point.

Since the refrigerant leaving the flooded evaporator is a newly formed vapor, the outlet temperature is the same as the evaporation temperature, which we know is around 7°C. Using the superheat equation, we can calculate:

Superheat = Evaporator outlet temperature – Compressor inlet temperature Superheat = 7°C – 7°C = 0°C

Why does superheat matter?

For one, it allows the expansion valve to regulate the amount of refrigerant that enters the chiller’s evaporator. If superheating is greater than zero in dry evaporators, it indicates that all the refrigerant is in the vapor state before entering the compressor. Excessive overheating can cause very high temperatures at the compressor outlet, which can affect the oil.

To improve the efficiency of modern large chillers and refrigeration equipment, superheat should be as close to zero as possible, always above. In chillers with bulb thermostatic expansion valves, the standard superheat value is usually 5°C maximum.

By understanding and calculating chiller refrigerant superheat, you can keep your system running smoothly and efficiently.

Chiller System Components

The Chiller System Components are divided according to their location into:

  • Chiller System components: located in the refrigeration circuit, for its operation and control.
  • Chiller system components: located in chilled water distribution.

Chiller Parts of Refrigeration Circuit for its Operation and Control:

The basic components of a chiller are the following:

  • Evaporator Chiller: to transfer the heat from the water to the refrigerant in the circuit, thus generating ice water.
  • Chiller compressors: to receive the refrigerant from the evaporator, raise its pressure and drive it to the circuit condenser.
  • Chiller condenser: to dissipate the heat of the refrigerant into the environment.
  • Expansion valve chiller: to recover low pressure and return low temperature to the refrigerant.
  • Chiller cooling towers: They are responsible for cooling the water that goes to the chiller condenser.
  • Chiller control board: It is in charge of controlling and optimizing the operation of the chiller’s refrigeration cycle.

Evaporator Chiller:

The evaporators used in chillers are:

  • Shell and Flooded Tube Chiller Evaporator.
  • Shell and Dry Tube Chiller Evaporator.
  • Shell and Coil Type Chiller Evaporator.
  • Double Tube Chiller Evaporator.
  • Baudelot type chiller evaporators.
  • Plate Chiller Evaporators.

Shell and Tube Chiller Evaporator Flooded.

  • A shell and tube evaporator consists of a shell, and a large number of straight tubes parallel to each other.
  • The coolant is inside the casing, and the water is inside the pipes. The coolant is fed through a float. The float is in charge of maintaining the constant level of refrigerant inside the casing.
  • The refrigerant outlet of the evaporator is located at the top, To exit the casing, the refrigerant must be in a vapor state, in order to reach the exit point.
  • They can be single-pass tubing or multi-pass.
  • Use fins out of the tube.
  • Steel pipes are used with ammonia.
  • Copper tubes are used with freons.
  • Ammonia has a high heat transfer coefficient, while Freons have a rather lower heat transfer coefficient, therefore fins are used on the refrigerant side.
  • In case of freezing, the water freezes in the tube, which causes the tubes to burst, as the water expands when it freezes.
  • They are not recommended for applications where the temperature of the liquid to be cooled may be below 3 ° C.

Shell and Dry Tube Chiller Evaporator:

  • It is made up of a shell and a large number of tubes parallel to each other.
  • A thermostatic expansion valve feeds the refrigerant to the evaporator.
  • The refrigerant supply is carried out according to the superheat at the outlet of the exchanger.
  • The refrigerant is inside the tubes.
  • This evaporator requires less refrigerant charge.
  • Fins are used inside the tubes.
  • Water flows through the casing.
  • The presence of baffles creates turbulence in the water, enhancing the transfer of heat.
  • The deflectors increase the residence time of the water in the housing.
  • In the case of freezing, the water has enough space in the shell for expansion.

Expansion valve chiller

Water cooled chiller parts

Chiller system componentes

chiller control board

chiller compressors

Where to learn all about chillers?

We have prepared a complete training in chilled water installations with chillers.

Chiller Training Courses

Chiller Training

We have chiller training, with everything that personnel working with chilled water systems need to know.

Part One Chiller Training:

  • The basic operation of the chiller.
  • Basic types of chillers.
  • Calculation of water chillers

Part two Chiller Training:

  • Efficiency study in chillers.

Part three Chiller Training:

  • Chilled water distribution systems.

Part Four Chiller Training:

  • Variants in cooling circuits in chillers.

Part Five Chiller Training:

  • Electronic control and electricity are applied to chillers.

Part Six Chiller Training:

  • Maintenance applied to chillers and ice water plants.

Chiller Tonnage Calculator

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°CBtu/lb°F
Specific Heat of Water141861
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/LKg/m3Lb/ft3
Water density1100062.43
NOTE: The density of the water allows us to transform the volumetric flow into the mass flow.

Heat Power Units Conversion Table:

Heat Power UnitEqualsEqualsEquals
1W0.86
Kcal/h		3.41
Btu/h		0.00028435
TRF
1 Btu/h0.25
Kcal/h		0.29
W		0.00008333
TRF
1 Kcal/h3.96
Btu/h		1.16
W		0.00033069
TRF
1 TRF12000
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 EqualsEqualsEquals
1 m3/s0.01 ft3/s16.67 L/min4.4 GPM
1 L/min0.26 GPM0.000589 ft3/s0.06 m3/s
1 ft3/s101.94m3/h1699 L/min448.83 GPM
1 GPM0.23 m3/h3.8 L/min0.000589 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.

Chiller Training Courses

Air Cooled Chiller Vs Water Cooled Chiller

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.

Chiller Training Courses

Industrial Water Chiller System

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.

Chiller Training Courses