What does q4 mean in the boiler system?
In the combustion process of solid fuel, some fuel often leaves the boiler with ash or fly ash without burning. This part of heat loss is called the heat loss of incomplete combustion of solid, which means q4 in boiler.
According to the inverse balance calculation formula of boiler thermal efficiency, the thermal efficiency of the boiler is equal to the calorific value minus various heat losses. For the boiler with solid fuel, the heat loss of solid incomplete combustion is the main heat loss in the total heat loss. Generally, the more ash there is, the more combustible materials will be caught in the ash, and the greater the heat loss will be.
ZOZEN Boiler takes many measures to control q4 to improve thermal efficiency
As a professional boiler manufacturer, ZOZEN Boiler not only needs to know what q4 stands for in the boiler, but also designs a reasonable furnace structure to make the fuel have enough residence space in the furnace, strengthen the mixing of fuel and air, and effectively reduce the heat loss of solid incomplete combustion. The actual measurement shows that the thermal efficiency of ZOZEN coal-fired boiler is over 82%, that of biomass boiler is over 88%, and that of circulating fluidized bed boiler is over 89%, which is generally superior to similar products.
-
DZW series biomass-fired reciprocating grate steam boilerLive Chat15-35 t/h1.25 MPa / 1.6 MPa / 2.5 MPa
-
DZL series biomass-fired steam boilerLive Chat2-10 t/h1-2.5 MPa
-
DZL series coal-fired steam boilerLive Chat2-10 t/h1-2.5 MPa
-
Email us
-
WhatsApp: +86 18861589035
WeChat: +86 13506150756
Live Chat

-
In modern manufacturing, 6S workplace management has become an important method for enhancing shop-floor management and is being widely adopted by more and more enterprises. ZOZEN Boiler actively practices the 6S philosophy. By optimizing the workshop environment and management processes, the company has effectively improved production efficiency and product quality. ZOZEN Boiler 6S management — workshop neat and orderly Sorting and Set-in-Order: The foundation of efficient operationsI...02 Dec 2025 -
In Shandong’s coastal fishmeal corridor, the reliability of steam, fuel cost, and environmental performance are now core to plant economics.Seasonal catch cycles, volatile gas prices and supply elasticity, plus tightening environmental standards, are pushing producers toward biomass boiler retrofits. With proven experience in seafood processing and mature biomass solutions, ZOZEN Boiler has become a preferred partner for Shandong fishmeal plants. Why steam is the lifeline From Rongchen...25 Nov 2025 -
As the global energy mix shifts and low-carbon transitions accelerate, more industrial enterprises are turning to renewable-energy boilers. As a key player in China’s industrial boiler sector, Wuxi ZOZEN Boiler Co., Ltd. (hereinafter, “ZOZEN Boiler”) has continued to advance biomass boiler technology. The SZL series, in particular, has been deployed across a variety of industry scenarios domestically and internationally, building a strong track record of project experience. ...18 Nov 2025











