Absorption chillers are an alternative to standard, electric chillers and work similarly to air conditioning systems. Instead of using electricity as power, these chiller systems run off heat. They are used when electric power conditions are poor, and they significantly reduce electricity costs associated with cooling, since they do not use a gas compressor. However, absorption chillers do require greater pump energy than electric chillers.
Quick links to Absorption Chiller Information
Advantages of Absorption Chillers
Absorption chillers are quiet, vibration free, reliable, low maintenance and don't use any CFC gases. Because they are driven primarily by heat energy instead of mechanical energy, they are used in industrial manufacturing plants that use boilers or have access to wasted heat from different machinery and processes.
Heat Sources for Absorption Chillers
Some useful heat sources for include:
In this way they reduce electric peaks in a building's electric load, cutting costs during the hottest times of the year. They may act as the sole cooling system, or work as part of an integrated cooling and heating system. Although more complex, absorption chillers act similarly to some residential refrigerators, which have a gas flame at the bottom and ice cubes at the top.
Design of Absorption Chillers
Components of absorption chillers must be integrated closely. The compressor, condenser and evaporator equipment are all contained in a single area within the facility. The process begins when a refrigerant, usually ammonia, carbon dioxide, sulfur dioxide, alcohol, brine or methane, is put under pressure, causing heat to build up in the compressor. The liquid is then converted to vapor, and moved into the condenser. The heat leaves, causing the gas to turn to liquid. The cooled liquid then travels to the evaporator, and turns into gas, pulling heat from a liquid coolant or from the air. The chilled air or fluid is then pumped into the process or facility, effectively cooling it down to a desired temperature. The pump is the only electrically-powered component.
Absorption chillers may be direct, meaning the heat source is gas or fuel that is burned in the unit, or indirect, using steam or other transfer fluids to bring heat from other sources like the boiler or various heat-generating industrial processes. The system may also use both the indirect and direct heat-drawing methods at the same time.
Additional Benefits to Absorption Chillers
Absorption chillers have been around for some time, but the true potential of the technology is just now coming to light for manufacturing plants around the world. Most absorption chillers use a type of technology known as co-generation.
- Features of Cogeneration
- Cogeneration is enabling the by-product of creating one type of energy to transform into a new form of energy itself. For example, the heat used to create electricity is then captured and used to heat water in the winter or to cool water for air conditioning in the summer. Heat is transformed into cool with the use of an absorption chiller.
- Absorption chiller manufacturers can benefit from cogeneration technology by creating cogeneration compatible chillers. Many companies already have created chillers with this capability, as more and more large factories, and even entire cities, strive to find new ways to go green.
- Using a cogeneration system is not only more energy-efficient and green than wasting the heat from electricity generation, but it is also cost-effective for companies as well. Typically, a water heater would have to create its own energy, or a chiller would have to use a separate energy source for creating chilled air. In co-generation, the same energy is used twice, which can potentially half any energy requirements of a factory or any other commercial building.
- Even some households now use a cogeneration system to eliminate energy waste. Construction companies around the world are utilizing the technology of co-generation and absorption chilling to reduce utility expenses and save energy in a variety of ways without implementing complicated systems. In today’s world of energy savings, absorption chilling is a simple way to save energy and money on a small or large scale.