The integrated low nitrogen condensing boiler features a large vapor space and an internal high-efficiency steam-water separator, reducing steam humidity to below 3%. Equipped with advanced digital intelligent control technology, it allows for remote precise monitoring of the entire combustion process. Reliable imported electrical components ensure safety and reliability during operation. It can be customized with remote communication interfaces as per customer requirements, enabling parallel control of multiple boilers. It can also print boiler operating parameters in real-time, with a computer memory system that records boiler faults and monitors its operation.

Complete set of safety accessories for boilers: water level control, pressure control, alarm devices, gas leak prevention, flame-out protection, over-temperature and over-pressure protection, explosion-proof door protection, etc. Multi-level safety interlock protection ensures the equipment is free of safety hazards. Equipped with internationally advanced imported burners, the boilers ensure complete combustion and harmful components in the flue gas are below the national standard, making them eco-friendly products.

Huzhou Boiler Factory Co., Ltd. is a professional manufacturer of boiler and pressure vessel equipment, and also the No.1 supplier of LPG storage tanks in China. Having evolved, it now encompasses Huzhou Boiler Factory Co., Ltd., its Installation Branch, and Shandong Zhongke Neng Artificial Environment Co., Ltd.  

Boiler Classification

Steam Boiler

In the first half of the 18th century, steam engines used in British coal mines, including Watt's early steam engines, operated at steam pressures equal to atmospheric pressure. By the latter half of the 18th century, steam pressures exceeding atmospheric pressure were used. In the 19th century, the common steam pressure reached about 0.8 MPa. Correspondingly, the earliest steam boiler was a large-diameter vertical cylindrical vessel for holding water, which was later modified to a horizontal vessel, with a fire burning in a brick-lined furnace beneath the vessel.

Double-flue boiler

As boilers grew larger, to increase the heating surface, fire tubes were added inside the boiler shell. Fire was burned at the front of the tubes, with flue gases exiting from the back and passing through brick-lined flues to the chimney, thereby heating the external surface of the boiler shell. This type of boiler is known as a fire tube boiler. Initially, only one fire tube was installed, referred to as a single fire tube boiler or a Cornish boiler. Later, two fire tubes were added, known as a double fire tube boiler or Lancashire boiler.

Horizontal External Combustion Reheat Tube Boiler

Around 1830, after mastering the production and expansion techniques of high-quality steel pipes, fire-tube boilers emerged. Some fire tubes were installed inside the boiler shell, forming the main heating surface of the boiler, with the flame (flue gas) flowing through the tubes. A large number of fire tubes were installed below the water line in the boiler shell, known as horizontal external-flame return flue-tube boilers. They have a lower metal consumption but require substantial masonry.

Drum pot

In the mid-19th century, the water-tube boiler emerged. The heating surface was the water pipes outside the boiler shell, replacing the boiler shell itself and the fire tubes inside. The increase in the heating surface area and steam pressure of the boiler was no longer limited by the diameter of the boiler shell, which was beneficial for enhancing the boiler's evaporation capacity and steam pressure. The cylindrical boiler shell in such boilers was then renamed to a drum, or called a steam drum. Early water-tube boilers only used straight pipes, which limited both the pressure and capacity of the boilers.

In the early 20th century, the development of steam turbines necessitated larger boilers with higher capacity and steam parameters. The straight tube boilers were no longer sufficient. With advancements in manufacturing techniques and water treatment, bent tube boilers emerged. Initially, multi-drum boilers were used. As water-cooled walls, superheaters, and economizers were adopted, and improvements were made to the steam-water separation elements inside the drums, the number of drums gradually decreased, saving metal while also enhancing the boiler's pressure, temperature, capacity, and efficiency.

Safety

Gas boilers differ from other gas appliances in that they have a unique installation location, high gas consumption, and are safety-critical products. Therefore, in North America, all gas fireplace products must pass stringent safety and environmental standards before being launched into the market. These standards are continuously updated with the development of products. Each type of fireplace product has corresponding specific safety testing standards. For instance, the testing standards for balanced flue gas fireplaces and chimney gas fireplaces are different, as are those for decorative gas fireplaces and heating gas fireplaces. Thus, North American balanced flue gas fireplace products should have certifications such as Ansi Z21.88 or CSA2.33, indicating that the product's safety and environmental standards have been met, and users can use them with confidence.

Auxiliary Boiler

Historically, fire-tube boilers, water-tube boilers, and firebox boilers were all types of natural circulation boilers. Due to varying heating conditions in the ascending and descending pipes, density differences were created, resulting in natural flow. While developing natural circulation boilers, the use of once-through boilers began in the 1930s, and auxiliary circulation boilers were introduced in the 1940s.

Forced circulation boiler

The auxiliary circulating boiler, also known as a forced circulation boiler, is an evolution from the natural circulation boiler. A circulating pump is added to the downcomer system to enhance the water circulation in the heating surface of evaporation. In a once-through boiler, there is no drum; the feedwater is sent to the economizer by the feed pump, passes through the water-cooled walls and superheater, etc., to become superheated steam for the turbine, with all the flow resistance in the various sections being overcome by the feed pump.

Composite circulating boiler

After World War II, both types of boilers experienced rapid development due to the demand for high-temperature, high-pressure, and large-capacity power generation units at the time. The aim of developing these boilers was to minimize or eliminate the need for drum, allowing the use of small-diameter tubes as the heating surface, which provides more flexibility in arranging the heating surface. With advancements in automatic control and water treatment technologies, they have gradually matured. At supercritical pressure, once-through boilers are the only type that can be used. In the 1970s, the largest single unit capacity was a 27 MPa pressure with a 1300 MW power generation unit. Subsequently, a composite circulation boiler was developed, which is a combination of auxiliary circulation boilers and once-through boilers.