The number of passes that the flue gas travels before exiting the boiler has been a good criterion when comparing boilers. As the flue gas travels through the boiler it cools, and therefore changes volume. Multiple pass boilers increase efficiency because the passes are designed to maximize flue gas velocities as the flue gas cools. ZOZEN has developed new design technologies in our WNS series boilers allowing for comparable efficiencies in fewer passes, resulting in smaller boiler systems that will fit in tighter quarters.
Stack temperature is the temperature of the combustion gases (dry and water vapor) leaving the boiler. A well-designed boiler removes as much heat as possible from the combustion gases. Thus, lower stack temperature represents more effective heat transfer and lower heat loss up the stack. The stack temperature reflects the energy that did not transfer from the fuel to steam or hot water. Stack temperature is a visible indicator of boiler efficiency. Any time efficiency is guaranteed, predicted stack temperatures should be verified.
Stack loss is a measure of the amount of heat carried away by dry flue gases (unused heat) and the moisture loss (product of combustion), based on the fuel analysis of the specific fuel being used, moisture in the combustion air, etc.
This is because, under normal circumstances, the exhaust temperature of the boiler cannot completely condense the water in the flue gas, and the difference between the low calorific value and the high calorific value is mainly in the part of the latent heat of vaporization, so the low heat is used. The value is calculated to reflect the true efficiency of the boiler. However, there will be some special circumstances. For example, if the boiler is a condensing boiler, the calculation of the condensed water portion should be calculated using the high calorific value.
1. Your existing system is inefficient
Efficiency is key when it comes to plant heating. Utilizing efficient equipment can save your company a significant amount of money in the long run and it is better for the environment. If you know that your existing system is not as efficient as it could be and it is in need of repair, it may be worth looking into thermal oil system replacement.
2. Your existing system features helical coil technology
Helical coils are common in thermal oil heaters from most manufacturers. But there are many reasons why serpentine coils are the better way to go when it comes to thermal fluid heating. Repairs to helical coils can be so expensive and time consuming that in many cases you are better off investing in new equipment – and it is well worth it to consider a new thermal oil system that features serpentine coil technology instead.
The combustion air preheater is definitely one of heat exchanger applications. Based on Figure 1 below, flue gas simply leaves steam boiler and passes via air preheater. The combustion air is passed through this equipment too to increase its temperature before being combined with boiler fuel.
Because the temperature of combustion air is lower than the temperature of flue gas, combustion air receive heat transfer from flue gas through combustion air preheater in the process of convection heat transfer. The heat transfer make temperature of flue gas lower and consequently minimizes its heat loss and also decreases the air temperature to stack.
ASME code – also known by its longer name: ASME Boiler & Pressure Vessel Code – regulates the design, development, and manufacturing of boilers used in a variety of industries and applications.
This code was developed by the American Society of Mechanical Engineers, an organization that has been around for well over 100 years and is focused on establishing safety codes and standards for mechanical equipment.
Within the industrial heating industry, ASME code is the established standard that many pieces of equipment are built to.
Heating systems that adhere to the specifications set forth by ASME code have been constructed according to guidelines intended to promote safety and quality. As such, heating equipment that is ASME code compliant has been thoroughly inspected to assure that it meets high safety and quality standards.
Economizer is one of steam boiler’s equipment which is used to heat feedwater before it is supplied into steam drum. Economizer is the heat exchanger equipment to increase boiler efficiency by absorbing heat recovery of flue gases. The lower temperature of flue gas out from stack, the heat loss will be less and the fuel which is needed to convert water into steam will be also less in certain circumstances. So it can be said that economizer can save the fuel efficiently. Economizer will make temperature of feedwater higher, so steam boiler can produce steam easily.
Gas fired boiler is a boiler which uses gas as its fuel. Gas fired boiler consists of some important components such as flame ignition, gas metering system, air compressor, air piping, gas piping, burner nozzles, and the others. Combustion process of gas fired boiler should be maintained and operated properly to produce efficient combustion result.
