• Steam English

Payback Time: 0 - 0 years

Energy Saving Potential: 0 - 2 percent

• "In common boilers, a certain amount of fresh water is required. In case it is not pure (H2O), this means impurities like dissolved salts and other substances are added to the system. During the operation these impurities accumulate in the boiler and reduce the heat transfer which leads to an efficiency decrease. In case any kind of impurities are added to the system, they need to be removed periodically, which is done in a blow-down step. The removed stream must be further replaced by fresh (cold) water. These two steps reduce the overall efficiency. However, when part of the blow-down heat is recovered, the losses can be reduced. In conclusion this leads to an optimisation problem, where on one hand the impurities need to be removed (to avoid a decrease of efficiency over time because of impurities accumulation) and on the other hand it should be done as seldom as possible to avoid energy losses. The optimum blow-down frequency and duration is depending on the specific system and especially the water quality. "

In common boilers, a certain amount of fresh water is required. In case it is not pure (H2O), this means impurities like dissolved salts and other substances are added to the system. During the operation these impurities accumulate in the boiler and reduce the heat transfer which leads to an efficiency decrease. In case any kind of impurities are added to the system, they need to be removed periodically, which is done in a blow-down step. The removed stream must be further replaced by fresh (cold) water. These two steps reduce the overall efficiency. However, when part of the blow-down heat is recovered, the losses can be reduced. In conclusion this leads to an optimisation problem, where on one hand the impurities need to be removed (to avoid a decrease of efficiency over time because of impurities accumulation) and on the other hand it should be done as seldom as possible to avoid energy losses. The optimum blow-down frequency and duration is depending on the specific system and especially the water quality.

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• Steam English

Payback Time: 0 - 3 years

Energy Saving Potential: 2 - 3 percent

• Heat is essential for many industrial processes, where steam is able to provide it. Steam as heat source can be delivered at many different temperature levels. Always related to a temperature level is the pressure, which is an important design parameter and is commonly elevated for steam systems. To produce steam, water is heated by burning fuels such as natural gas, natural gas, oil, biomass or others in a burner. The required oxygen is commonly provided via air which is supplied via a burner.

Heat is essential for many industrial processes, where steam is able to provide it. Steam as heat source can be delivered at many different temperature levels. Always related to a temperature level is the pressure, which is an important design parameter and is commonly elevated for steam systems. To produce steam, water is heated by burning fuels such as natural gas, natural gas, oil, biomass or others in a burner. The required oxygen is commonly provided via air which is supplied via a burner.

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• Steam English

Payback Time: 0 - 0 years

Energy Saving Potential: 0 - 1 percent

• "In combustion a fuel is converted chemically to generate heat. This conversion requires a certain amount of oxygen, commonly provided via air. When fuel and oxygen are in perfect balance, the combustion is called stoichiometric. The minimum required oxygen is depending on fuel and composition. For an ideal combustion the theoretical minimum amount of oxygen can be determined. However, as the combustion is commonly not ideal (varying fuel composition, mixing problems, issues with residence time of fuel in combustion chambers, etc.) additional oxygen is provided to completely burn the fuel. This increases the fuel usage and flue gas stream which results in heat losses, lowering the overall boiler efficiency. "

In combustion a fuel is converted chemically to generate heat. This conversion requires a certain amount of oxygen, commonly provided via air. When fuel and oxygen are in perfect balance, the combustion is called stoichiometric. The minimum required oxygen is depending on fuel and composition. For an ideal combustion the theoretical minimum amount of oxygen can be determined. However, as the combustion is commonly not ideal (varying fuel composition, mixing problems, issues with residence time of fuel in combustion chambers, etc.) additional oxygen is provided to completely burn the fuel. This increases the fuel usage and flue gas stream which results in heat losses, lowering the overall boiler efficiency.

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• Steam English

Payback Time: 0 - 3 years

Energy Saving Potential: 0 - 20 percent

• Steam is an expensive utility. Steam losses due to leakage might lead to a significant economic loss and can be as high as 19% of the total steam energy production costs (Swagelok Energy, 2014). Apart from that leaks can also present a safety hazard. Steam leaks occur everywhere but most common in places such as flanges and joints, pipe fittings, valves, steam traps and pipe failures. The losses caused by even a small leak can be significant.

Steam is an expensive utility. Steam losses due to leakage might lead to a significant economic loss and can be as high as 19% of the total steam energy production costs (Swagelok Energy, 2014). Apart from that leaks can also present a safety hazard. Steam leaks occur everywhere but most common in places such as flanges and joints, pipe fittings, valves, steam traps and pipe failures. The losses caused by even a small leak can be significant.

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• Steam English

Payback Time: 0 - 3 years

Energy Saving Potential: 0 - 10 percent

• "If steam traps work correctly, they remove unwanted condensate from the system without significant losses of steam. However, steam trap failure is often the cause of significant steam system heat losses. They can generally fail in two ways: failed open and failed closed. A failed open steam trap constantly releases steam from the system, resulting in an increased boiler load and energy costs. Failed closed steam traps do not remove the condensate from the system, leading to multiple problems: Water collected at heat exchangers will lower the heat transfer, water droplets entrained in the steam can damage the equipment, and a failed closed trap serving a steam distribution header can result in a water hammer that can cause extreme damage to the system. It is common that in steam systems, which have not been maintained for several years, that 15% to 30% of the installed steam traps are defective. Leaks and failed steam traps can imply costs of multiple thousand euros per year and steam trap. "

If steam traps work correctly, they remove unwanted condensate from the system without significant losses of steam. However, steam trap failure is often the cause of significant steam system heat losses. They can generally fail in two ways: failed open and failed closed. A failed open steam trap constantly releases steam from the system, resulting in an increased boiler load and energy costs. Failed closed steam traps do not remove the condensate from the system, leading to multiple problems: Water collected at heat exchangers will lower the heat transfer, water droplets entrained in the steam can damage the equipment, and a failed closed trap serving a steam distribution header can result in a water hammer that can cause extreme damage to the system. It is common that in steam systems, which have not been maintained for several years, that 15% to 30% of the installed steam traps are defective. Leaks and failed steam traps can imply costs of multiple thousand euros per year and steam trap.

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