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.
-
WNS series gas-fired (oil-fired) skid-mounted hot water boilerLive Chat0.7-2.8 MW1.0 MPa
-
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
-
Email us
-
WhatsApp: +86 18861589035
WeChat: +86 13506150756
Live Chat

-
From May 6 to 7, 2026, ZOZEN Boiler will participate in Palmex Indonesia 2026 at Jakarta International Expo (JIEXPO), Indonesia. ZOZEN Boiler will welcome visitors at Booth 190 & 192. As an industry event focused on the palm oil sector in Southeast Asia, the exhibition brings together companies involved in palm oil processing, supporting energy systems, and industrial equipment, offering ZOZEN Boiler a valuable opportunity to meet customers from Indonesia and surrounding markets. ZOZEN Bo...28 Apr 2026 -
Bangladesh is one of the world’s major producers and exporters of garments and textiles. With a well-developed industrial chain covering textile, dyeing, printing, and garment manufacturing, long-term demand for industrial steam remains strong. In production processes such as dyeing, washing, drying, and finishing, steam boilers play an important role in ensuring stable heat supply. As local textile enterprises place greater emphasis on energy consumption control, fuel utilization, and ope...21 Apr 2026 -
In Pakistan, garment manufacturing and fabric processing remain important parts of industrial production. For these factories, steam is not an auxiliary utility but a core part of the production chain. Processes such as dyeing, drying, heat setting, and finishing all require a stable and continuous steam supply. Any fluctuation in steam output may affect production rhythm. Against this background, more textile companies in Pakistan are paying closer attention to fuel adaptability, operating sta...14 Apr 2026











