At present, the domestic urgently needed environmental protection instruments and meters mainly include: atmospheric environmental quality monitoring instruments and automatic monitoring systems; coal gas power stations or boilers as the representative of the flue gas analysis instrumentation monitoring system; surface water environmental quality testing instruments and monitoring systems; to urban sewage treatment Plants and high-concentration organic wastewater represent pollution source monitoring instruments and automatic control systems.
The Central Government budget for the development of environmental protection equipment and equipment amounts to 150 million yuan Recently, the annual meeting of the China Association for Environmental Sciences in 2012 was held in Beijing. In 2012, in the special national major scientific instrument and equipment development project, the central budget for supporting the development of environmental protection instruments and equipment has reached 150 million yuan.
The environmental protection industry is a new industry that has flourished in the world in the past 20 years. It has now become a new economic growth point for some countries. The global environmental protection industry is growing at a rate of 7.5% per year, and the average annual growth rate of China's environmental protection industry is above 15%. According to statistics, the output value of China's environmental protection industry reached 1,100 billion yuan in 2010, accounting for 2.7% of GDP in the same year. There are 35,000 national environmental protection companies, 3 million people are employed, and a number of modern environmental protection companies with an annual output value of over one billion yuan have emerged. The Ministry of Environmental Protection has approved the construction of 26 key national environmental protection laboratories and 29 engineering and technical centers.
The main problems faced by the environmental protection equipment market Currently, most of the environmental monitoring instruments and meters produced in China are medium and low-grade products. The products have a single function, high failure rate, low added value, and far from meeting actual needs in terms of variety and quantity. When used, there are problems such as low monitoring frequency, large sampling error, and inaccurate monitoring data. These problems not only affect the scientific decision-making of environmental management and the seriousness of law enforcement, but also tend to dampen the enthusiasm of enterprises for pollution control and environmental protection. High-quality analyzers, special-purpose monitoring instruments, and automatic monitoring systems are mostly introduced from abroad, so the share of domestic instruments is very small. There are several main reasons why this situation is caused:
(1) The operating system of the company is not perfect and tends to converge. The performance of the large-scale state-owned enterprises has a problem in their operation mechanism, and they cannot play a good role as a backbone; many small and medium-sized enterprises flock to the market, lack technology, lack funds, and repeat at low levels. The quality and performance of the instrument cannot be compared with imported equipment. contend.
(2) The product structure is irrational. There is a shortage of high-tech products, and the oversupply of low-end products has contradictions between supply and demand, and it is unable to adapt to strict environmental management needs. At present, the environment monitoring instrument industry is small in scale, backward in technology, and disorderly in competition, and in particular, problems such as unstable technical performance and low level of integration have led to the oversupply of middle- and low-end products, as well as high-quality and high-performance environmental protection instruments. There is no domestic production, and most of them rely on imports.
(3) Low research and development capabilities. The research and development capabilities of Chinese companies are still not much different from those of foreign companies. At the same time, there is also a lack of mechanisms for close cooperation between research institutes and enterprises. Scientific research results cannot be quickly realized in industrialization. The government's investment in developing and developing environmental science instruments and venture capital are also insufficient.
Relevant experts believe that manufacturers of environmental monitoring instruments and equipment will be divided in two directions: one is a large-scale comprehensive enterprise with international competitiveness, and the other is a group of highly specialized small and medium-sized enterprises, mainly specialized in certain types of technologies or Proficient in a certain product or service, characterized by small scale, staffed, and experienced. A large number of production enterprises developed rapidly and began to change the status of China's environmental monitoring field by relying only on imported instruments. At the same time, enterprises, universities, research institutes, design institutes, finance, and market agencies have realized communication and interaction to promote the formation of large-scale production companies and large-scale markets.
A reaction turbine is a type of Steam Turbine that works on the principle that the rotor spins, as the name suggests, from a reaction force rather than an impact or impulse force.
In a reaction turbine there are no nozzles to direct the steam like in the impulse turbine.Instead, the blades that project radially from the outer edge of the rotor are shaped and mounted so that the shape between the blades, created by the cross-section, create the shape of a nozzle. These blades are mounted on the revolving part of the rotor and are called the moving blades.
The fixed blades, which are the same shape as the moving blades, are mounted to the outer casing where the rotor revolves and are set to guide the steam into the moving blades. Below is a simple diagram of reaction turbine blades:
Reaction Turbine Principle:
In the case of reaction turbine, the moving blades of a turbine are shaped in such a way that the steam expands and drops in pressure as it passes through them. As a result of pressure decrease in the moving blade, a reaction force will be produced. This force will make the blades to rotate.
Reaction Turbine Working:
A reaction turbine has rows of fixed blades alternating with rows of moving blades. The steam expands first in the stationary or fixed blades where it gains some velocity as it drops in pressure. Then enters the moving blades where its direction of flow is changed thus producing an impulse force on the moving blades. In addition, however, the steam upon passing through the moving blades, again expands and further drops in pressure giving a reaction force to the blades.
This sequence is repeated as the steam passes through additional rows of fixed and moving blades.
Note that the steam pressure drops across both the fixed and the moving blades while the absolute velocity rises in the fixed blades and drops in the moving blades.
The distinguishing feature of the reaction turbine is the fact that the pressure does drop across the moving blades. In other words, there is a pressure difference between the inlet to the moving blades and the outlet from the moving blades.
Special Aspects of Reaction Turbines
- There is a difference in pressure across the moving blades. The steam will, therefore, tend to leak around the periphery of the blades instead of passing through them. Hence the blade clearances as to maintain as minimum as possible.
- Also, due to the pressure drop across the moving blades, an unbalanced thrust will be developed upon the rotor and some arrangement must be made to balance this.
Reaction Steam Turbine
Shandong Qingneng Power Co., Ltd. , http://www.qnpturbines.com