Comparison of operation of Low CO₂ Low Nox Condensing Boiler and multi-tubular once through boiler

• Installing ten 2t/h once through boilers in the business place using steam 20t/h in total, you should do cycle operation in 10-step among 10 boilers. In this case, energy costs for fuel and electricity increases and operating noise at termination of ignition of the boiler increases, too. Once through boiler has lots of problems providing necessary steam when needed.
• Installing two 10t/h low-carbon condensing boilers allows you to do continuous proportional controlling operation with stable pressure within the load variation range of 2t/h ~ 20t/h.
• A big blower and feed water pump of large-capacity low-carbon condensing boiler function as a ultra power saving infinite multi-tubular boiler by operating the motor consuming the minimum electric power according to the capacity by inverter.

Is it true that large-scale boiler has more heat loss than once through boiler?

• Once through boiler has a small quantity of water so that it generates steam in five minutes. On the contrary, condensing boiler has a large amount of water so that it generates steam in thirty minutes. The thing that you should operate the boiler and preheat the boiler water for 25 minutes consuming a lot of fuel is a disadvantage of condensing boiler. However, it is a one-time disadvantage at initial operation of the boiler. Not blowing off the boiler water with high temperature and closing the exhaust gas damper while stopping the boiler at night would shorten the time to generate steam to 8~10 minutes when re-operating the boiler in the morning as the latent heat is preserved in the boiler water.
• Consider that combustion in initial 25 minutes of operating time does not waste fuel in the air, but rather temporarily stores it in the boiler water.
• Once through boiler has a small amount of water, which results in carry over due to concentration of the boiler water during the operation. Also, blowing off of the boiler water is needed when stopping the boiler at night or in a temporary manner, and heat loss occurs at this time. Frequent cold operating shorten the life of the boiler.

Once through boiler costs a lot of fuel expense and electric power expense as its operating efficiency is very low.

• It is said that the efficiency of the once through boiler is more than 95%. However, this number is gotten after continuous operation of testing once through boiler longer than one hour. It is a small boiler having a small quantity of water and the quantity of evaporation itself is small, too. Even when you open and close the steam valve a little according to load variation, there occurs a lot of changes in pressure so that it repeatedly operates and stops two-digit times an hour, five-digit times. Loss generated at this time is as follows:
• Ignition fuel is required 3 times more than the normal operation (same as car), and Purge loss is more than 6% of the fuel consumed in total. Operating power of the blower and feed water pump motor is five times larger than the normal operation, so consumption electric power increases. For example, think about losses and troubles such as rice pot costs, loss of leftover of rice, loss of labor expense, and other troubles when making rice for 100 people with three rice pots for 33 people and twenty rice pots for 5 people, respectively.
• Low CO₂ Low Nox Condensing Boiler saves fuel and electricity by burning the burner with the inverter controlling continuously the number of rotation of the boiler and controlling the amount of gas in proportional control type according to pressure variation, with the operating efficiency more than 100%. In addition, it saves electric power and provides high-quality steam by detecting the speed of the boiler water changing according to the amount of steam evaporation and with the inverter exercising proportional control feed water with continous feed water device controlling the number of rotation of the feed water pump.

Have you ever thought about the warranty service costs?

• As once through boiler repeatedly goes on and off two-digit times an hour and five-digit times a year, burner, blower, feed water pump, gauges face frequent failure and shortened product life. If water treatment goes wrong because of a small heat transfer area and a small quantity of water. Think about the cost incurred in replacement of the body and the warranty service when installing more than 10 boilers of this kind. The thing that profit from the warranty service is larger than that from the sales of the boiler, and employees for warranty service are several times more than those for manufacturing the boiler shows the reality
• Low CO₂ Low Nox Condensing Boiler has a large heat transfer surface (five times larger than once through boiler), and a lot of quantity of water (20 times), so it is not sensitive to the quality of water and its life is long as it adopts automatic proportional control combustion and continuous feed water type. As the number of installed boilers is small because the capacity is large, and it is continuously operating, failure of burner, blower, feed water pump, and gauges do not occur frequently, so its cost for warranty service is almost zero.

Pipe burst of once through boiler due to scale