In order for a steam boiler to work properly, it is important that all of the parts are in good condition. One of the most important parts of a steam boiler is the condensing section. The condensing section is responsible for converting the steam back into the water so that it can be reheated and reused.
If this section is not working properly, the boiler will not be able to generate enough heat to keep your business running. In this blog post, we will discuss some common problems with the condensing section and how you can troubleshoot them. Stay tuned!
If you’re wondering, “What is a condensing steam boiler?” this article is for you. In this article, I’ll talk about the Condenser and Condensate Extraction Pump. You’ll also learn about the differences between the two types.
Hopefully, this will answer your question. If not, read on to learn more about both. These parts play an important role in condensing steam boilers.
Table of Contents
What is condensing steam boiler?
A condensing steam boiler is an excellent option for reducing your energy bill and saving money. Compared to conventional boilers, condensing boilers use a fraction of the fuel to produce hot water. As they are capable of recovering latent heat from vaporization, they can produce hot water with even greater efficiency.
This waste heat is converted into heat by the condensing process, which means you can use less fuel to achieve the same temperature.
A condensing boiler’s primary and secondary heat exchangers are constructed of materials that are resistant to acidity. Because the final exhaust from condensing boilers is so much cooler than that of atmospheric boilers, they require a mechanical fan to disperse the exhaust.
Domestic applications usually use low-temperature piping, which does not require insulation and does not have to be insulated. The conventional metal flue is not recommended, as the corrosive nature of the flue products makes it incompatible. In contrast, especially rated flue materials are permitted.
During the condensing phase, the economizer transfers about 100-200 degrees of heat from the exhaust gases to the feed water. Feedwater enters the boiler at around 350-450 degrees F, despite being pre-heated during the condensation phase.
As a result, the boiler needs only to raise the temperature of the feedwater by 40 to 140 degrees Fahrenheit to produce steam.
Parts of condensing steam boiler
A condensing steam boiler collects water from exhaust steam and uses it to heat water. The condenser consists of vertically-perforated type plates.
At the bottom of the condenser is a pump to remove condensate. This pump draws exhaust steam into the lower part of the tubes. In the upper half of the tubes, cold water passes through and is collected. The condenser is filled with baffles to reduce the water vapor escape.
A condensing boiler collects the latent heat of vaporization by recovering this energy. This process increases efficiency by 10 to 12 percent. The increase depends on the temperature of the water that is returned to the boiler after condensing.
However, a condensing boiler is always as efficient as a non-condensing boiler. And there are benefits to both the boiler and its owners.
The condensing steam cycle is illustrated in Figure 22.8. A Fuel is burned in a boiler, converting the heat into steam. The exhaust steam then expands through a turbine, condensing in a heat exchanger. The exhaust steam is then returned to the boiler through feed pumps.
This process is known as the Rankine Cycle. The expansion of steam in a turbine should be isentropic. In reality, there is a small amount of irreversibility that can cause the expansion process to become less than ideal.
Condenser
A condensing steam boiler is a system of pipes that condenses hot water into steam. These tubes are made of different materials including stainless steel, copper alloys, and titanium. As a result, they are always in contact with circulating water.
The circulating water may act as an electrolyte between the tubes and water boxes. The longer the tubes, the more prone they are to electrolytic corrosion. Most modern power plants use sea water-based condensers as it has the lowest anodic properties. River water or lake water with pollutants is not advisable to be used as condenser cooling water.
The outermost body of the condenser contains the tubes and heat exchangers. It is made up of carbon steel plates. These plates also act as baffle plates. Long tubes are supported by intermediate plates.
The condensate collected at the bottom of the condenser is pumped out via a hot well and reused as boiler feedwater. It is important to maintain the efficiency of the condenser and the steam boiler by regularly maintaining the boiler.
Condensate Extraction Pump
The Condensate Extraction Pump is part and parcel of condensing steam boilers. It removes the air and cools condensed steam back into the boiler. This helps boiler-based HVAC systems to work efficiently and save money.
It is essential to consider the Condensate Extraction Pump when purchasing a new boiler. Listed below are some of the benefits of this pump.
The Condensate Extraction Pump removes the condensed steam from the power plant’s condenser. It then delivers this condensate to a deaerator through low-pressure feed water heaters. The condensate at the CEP’s inlet is under pressure, below atmospheric pressure, but above the boiler’s water level. The Condensate Extraction Pump consumes electrical power as it circulates the condensate.
The Condensate Extraction Pump is an important component of condensing steam boilers. This pump is necessary for the condensate to exit the boiler. The pumps are typically located in the lower part of the boiler. The Pump has to be properly positioned in order to prevent a backup in flow. The pump should be positioned at a height that will prevent it from flashing or being damaged by the condenser.
Hot Well
A condensing steam boiler is a device used to convert waste heat from a thermal system into usable feedwater. The condensate from the boiler is converted into usable feedwater by using a pump. The system includes three parts: the main condenser, the hot well, and the air ejector condenser. These parts are connected by a steam turbine.
The main control valve, or ejector condenser, receives exhaust steam from the boiler. As the exhaust steam contacts the cooling water, it converts into low-pressure steam.
A condensate extraction pump is installed near the steam condenser to pump the condensate to the Hot Well. This pump also removes air from the condenser, which helps in the circulation of the cooling water and the flow of the condensate downward.
The economizer transfers heat from the exhaust gas to the feed water before it enters the steam drum. By doing this, the boiler reduces its fuel consumption by reducing the amount of fuel required to raise the water’s temperature.
The water enters the economizer at a temperature of approximately 246-249degF and 750-800 psi. As a result, the system produces less than half of the initial water temperature.
Boiler Feed Pump
A boiler feed pump is a device that pumps water into a steam boiler. The water can be either freshly supplied or accumulated in a condenser. When the water is heated, it is converted to steam, and the excess energy is then dumped into the condenser.
The condensed water then flows back into the boiler, where it is cooled. The boiler feed pump helps prevent thermal shock to the condenser and boiler. In addition, this pump ensures that the steam is not released into the atmosphere, which allows it to save considerable amounts of energy.
A boiler feed pump is usually equipped with a variable speed drive to reduce operating costs. Variable speed drives are usually installed in typical British sets and are a better choice than a fixed-speed drive. Variable speed drives also reduce operational losses.
Because all conventional plant is designed for two-shift operation, the boiler feed pump is configured to provide higher feedwater flow than it normally does in order to cope with transient conditions and pump wear. In this way, the boiler feed pump provides an operational margin, even when the pressure in the boiler falls below its design range.
Cooling Water Pump
In a condensing steam boiler, the cooling water pump circulates the water through the boiler’s condenser to remove excess heat. The raw water is fed into the cooling tower and becomes the condensate. When the water temperature drops below 10 deg C, it becomes ready for reuse. Another pump, called a booster pump, keeps the feed pump from cavitating.
The condensate cooler is a component that reduces the temperature of the exhaust stream. By reducing the temperature, it can be recycled as feed water, reducing the power consumption of the boiler.
The cooling water pump also prevents condensation of the hot water, reducing the amount of heat supplied per kilogram of steam. The cooling water pump has many advantages, but these are not the only ones.
The temperature and relative humidity of the surrounding air determine the efficiency of a condensing steam boiler. While the boiler can recover all of the water vapor from combustion, the lower the relative humidity, the less water vapor can be recovered.
The cooling water pump is an essential component of a condensing steam boiler. A Grundfos circulator is a key component to maximizing the efficiency of this system.
Air Extraction Pump
The condensing steam boiler has three parts – a hot well, the main condenser, and an air extraction pump. The hot well receives an exhaust stream, which flows downward. The exhaust steam then moves radially inward across tubes to a suction pipe.
The air extraction pump extracts air from the condenser, which helps the cooling water circulate and move downward.
The Air Extraction Pump draws water out of the condenser under pressure to feed the system with condensate. It is a two-stage centrifugal pump with a specified suction head. A condensate level control system is required to properly function.
The first stage impeller takes almost boiling water and discharges it at a slight positive pressure, while the second stage impeller provides the necessary system pressure at the outlet.
The condenser has tubes that carry the water vapor – the vapor – through them. The induced draft fan then removes this water and passes it into a piping system, where it is used as feed water for the boiler.
An induced draft pump reduces the overall power use of the power plant. It also allows for more efficient use of steam. This way, condensing steam boilers can be smaller, more efficient, and more reliable.
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