Natural circulation and forced circulation are two kinds of circulation states during the operation of the boiler, and the two are essentially different. Fang Kuo Xiaobian will compare and compare these two cycle states, so that you can better understand the boiler operation knowledge.
First, the natural circulation.
Working principle: The operation mode of actively promoting the water circulation by relying on the density difference caused by the heating of the working medium between the falling pipe outside the furnace and the rising pipe in the furnace. The circulation circuit is composed of a drum, a down pipe, a header, a riser pipe, a steam water introduction pipe and the like. The pot water descends from the outer down pipe of the furnace into the lower header of the water wall, and then is heated into a steam-water mixture (containing steam rate of 5-25%) through the furnace water wall (ie, the riser pipe), and then enters the drum through the soda water introduction pipe to perform steam-water separation. The saturated steam is sent to the superheater, and the pot water still returns to the down tube to continue the circulation.
The main features of natural circulation boilers are:
1. Work only under sub-critical pressure. Under the subcritical pressure, the natural circulation boiler with the flue gas parameter of 16.6~18.2 MPa and the working pressure of the drum reaches 18.6~20.6 MPa, and the natural circulation still has sufficient water circulation driving force to achieve safe and reliable operation.
2. Has a fixed evaporation section end point. The drum separates the two sections of evaporation and superheating, which serve as the heat accumulator and water reservoir of the boiler respectively.
3. Under the normal operating conditions, the design is correct, can maintain the appropriate circulating water flow rate or cycle rate (the ratio of the circulating water volume entering the rising pipe to its steam production), and has good self-compensation ability, that is, the heat absorption of the circuit increases. The circulating water flow rate also increases.
4. Under the subcritical pressure, the water-cooled wall often adopts an internally threaded pipe to ensure the ability to effectively prevent the working fluid in the pipe from deviating from the nuclear boiling (DNB).
5. The salt water concentration and steam quality of the pot water can be maintained by continuous sewage discharge in the drum. The quality of the feed water can be lower than that of the DC boiler, which can reduce the cost of the chemical water treatment part.
6. The resistance of the steam-water system is small, and the water supply pressure is not high, which can reduce the power consumption of the feed pump.
7. The drum is thick-walled, the cost is high, and there is a problem of temperature difference between the upper and lower sides and the inner and outer walls, and the starting and stopping time is extended.
Second, the mandatory cycle.
Working principle: Under the action of the water pump head, the working medium passes through the preheating, evaporation and overheating heating surfaces, and is preheated, evaporated and superheated to the required temperature.
The water or steam in the forced circulation boiler is not only powered by the difference in density between water and steam, but also requires a certain pump work to circulate in the heating pipe. Due to the good water circulation, the forced circulation furnace has a very low requirement for the water supply speed; the working pressure is generally large, and the material and the wall of the boiler tube are required to be high. The drum of the forced circulation boiler is no longer necessary. It can have a drum and can have no drum. However, the pump head has higher requirements and consumes more electricity. When the pump stops running, the flow of water in the pot also stops, and a reliable method is needed to prevent the water from vaporizing the water.
The difference between the forced circulation boiler and the natural circulation boiler is that the circulation between the downcomer of the natural circulation boiler and the heating surface is generated by the natural indenter between the two, and the forced circulation boiler is forced by the furnace water circulation pump. The forced circulation boiler on the equipment has a furnace water circulation pump (compulsory circulation pump), while the natural circulation boiler does not.
The horizontal boiler evaporation section is generally forced circulation, and the vertical boiler evaporation section is not necessarily a natural circulation, but may also be a forced circulation.
With the boomingdevelopment of the mobile Internet industry, new technologies, new services and data centers are becoming more and more closely related, and all walks of life are growing rapidly in the "cloud". The massive data processing needs make the Internet industry face new challengesof the era of comprehensive cloudification of data storage and transmission modes. In this context, cloud computing integrates various forces to form a joint force, which brings convenience to the development of various tasks and creates a new business model.
As the backbone of the special equipment manufacturing industry, Fangkuai Boiler also follows the general trend of the development of the cloud era and deepens the social driving force of "cloud data". Leading the development of the industry, Fangkuai Boiler will facethe situation of opportunities and challenges.
The full name of the Canton Fair is China Import and Export Fair, which was officially established on April 25, 1957. This year, it is the 127th session. As a comprehensive international trade event with the longest history, highest level, largest scale, most complete product variety, and best transaction effect in China, the Canton Fair has also been favored by many well-known domestic and foreign companies, and has contributed to the promotion of economic globalization.
Affected by the international epidemic situation, the Canton Fair is also flexible and adaptable, with the help of the global interconnection, it is held online.
As one of the countries along the “Belt and Road”, Uzbekistan has maintained friendly economic and trade relations with my country. This time, with the aid of the long-term economic cooperation between China and Uzbekistan, Fangkuai Boiler Company has also reached a long-term strategic cooperative relationship with a local trading company in Uzbekistan. This is undoubtedly a further expansion of Uzbekistan and other companies for FANGKUAI Boiler Company. The international market in Central Asia.
The company that cooperated with Fangkuai Boiler Company this time is a well-known local trading company in Uzbekistan, which involves many industries such as food processing, raw oil and automobile manufacturing. The establishment of this partnership also laid a solid foundation for FANGKUAI Boiler to expand local food, chemical, automotive and other industries.
The company attaches great importance to this cross-border cooperation, and has sent several teams to visit the mainland of China. After a comprehensive evaluation of the company's overall strength, advanced technology and after-sales service, it was determined that FANGKUAI Boiler is a very worthy enterprise, and the two parties reached a good cooperation.
This year, FANGKUAI Boiler accepted investigations from leaders of the National Committee of the Chinese People's Political Consultative Conference, Comrade Jiang Zuojun, Deputy Secretary-General, Comrade He Jinping, Deputy Governor of Henan Province, Investigation Team of the Provincial People's Congress, Deputy Secretary of Anyang, and Mayor Jin Lei And inspections, and with the strong professional technology and various research and development results have been praised and encouraged by superior leaders.
This year, FANGKUAI Boiler brought a variety of boiler products to China International Corrugated Paper, Beijing ISH, 2019 Pharmaceutical Expo, auto parts and other industry exhibitions. As "the most influential brand of industrial boilers" and the leading domestic manufacturer of environmental protection boiler equipment, FANGKUAI Boiler shines in major exhibitions.
Among them, the "Europe" series products launched by FANGKUAI combine the characteristics of the corrugated packaging industry and completely solve the production difficulties of the industry. Through bold innovation and repeated attempts, they successfully reduced the input cost for users of the paper packaging industry. Reduce energy consumption.
At the 2019 Pharma Expo, Fang Kuai is an unshakable mission, providing safe and reliable solutions for the pharmaceutical industry in the recovery of condensed water and other well-known pharmaceutical companies such as Yunnan Baiyao and China Resources Pharmaceuticals. The industry response is evident.
This year, we signed strategic cooperation agreements with leading brands in the chemical, machinery, pharmaceutical, automotive, food, communications, heating, military and other industries to provide them with suitable boiler equipment and systemized solutions for a long time. These include but are not limited to well-known brands such as Qinghai Salt Lake, Yutong Automobile, Sankeshu Lacquer, Yili, Haier, ZTE, JD.com, and Huare.
Recently, FANGKUAI Group was invited to participate in the year-end event of the automotive supporting industry. When looking at the event location, it was actually in Beijing Yanqi Lake International Conference Center. This place is of great significance to FANGKUAI Group!
Just in 2014, leaders of various countries gathered at the Yanqi Lake International Conference Center in Beijing to celebrate the event. As the most influential official forum for economic cooperation in the Asia-Pacific region, the APEC conference venues adhered to the concept of "low-carbon environmental protection and technological innovation" during construction, which coincided with FANGKUAI Group's green environmental protection concept. As the only company in China As a boiler enterprise that has passed the test of ultra-low nitrogen oxide emissions, FANGKUAI Group has become a company that provides designated products for heating and hot water for the APEC summit.
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ENTER Engineering Pte. Ltd., founded in 2012, is one of the fastest growing companies in the oil and gas and industrial construction markets in Central Asia and the Russian Federation. It is currently responsible for trade in Uzbekistan, Russia, Kazakhstan, Singapore, Dubai and other countries. The company specializes in Engaged in the construction of industrial and technical facilities of various levels of complexity. With extensive experience in the oil and gas industry, ENTER Engineering has fulfilled EPC contracts and performed a variety of complex construction projects on a turnkey basis.
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