The most popular one is gas-fired cogeneration, wh

2022-07-27
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Don't call gas-fired cogeneration as natural gas distribution any more. They have ten differences. On June 27, 2018, the State Council issued the notice on printing and distributing the three-year action plan for winning the blue sky Defense War (GF [2018] No. 22), In the action plan "III. accelerating the adjustment of energy structure and building a clean, low-carbon and efficient energy system", it is clearly mentioned that "the interruptible users such as natural gas peak shaving power stations will be developed in an orderly manner, and in principle, natural gas cogeneration and natural gas chemical projects will not be built."

this heavyweight document issued by the State Council can be described as "one stone arouses a thousand waves, and two fingers pop up a thousand sounds", which has exploded in the distributed energy industry, and the natural gas distributed energy has suffered a "lying gun". For this reason, the distributed energy special committee of China Urban Gas Association also specially organized a meeting to study and report the situation to the relevant departments of the national energy administration, with a view to correcting the name of natural gas distributed energy and avoiding "accidental injury" to natural gas distributed energy due to the national restriction on natural gas cogeneration

affected by this, Shaanxi, Jiangsu, Shandong and other places have successively stopped the approval of natural gas distributed energy projects, because in the understanding of some local government officials, natural gas distributed energy is natural gas cogeneration, and natural gas cogeneration is natural gas distributed energy, the two are the same thing, there is no difference. It is no wonder that even those who have worked in the natural gas distributed energy industry for many years may not be able to clearly explain the differences and connections between the two, let alone government officials who do not take this as a professional

in view, there are two reasons for the deviation of local governments' understanding of natural gas distributed energy:

first, since the national development and Reform Commission, the Ministry of finance, the Ministry of housing and urban rural development, the national energy administration and other four national ministries and commissions issued the guiding opinions on the development of natural gas distributed energy (fgny [2011] No. 2196) in 2011, the difference between natural gas distributed energy and gas-fired cogeneration, There is no authoritative interpretation, especially there is no clear definition of the total installed capacity and single machine scale of the two, so that every interest group understands and interprets the two concepts according to their own interests. As a result, the two concepts are understood in different words, and no consensus has been reached until September 30 last year

there are even great disputes about the definition and content of natural gas distributed energy. At present, there are at least three official expressions. The definition of natural gas distributed energy in the guiding opinions on the development of natural gas distributed energy issued by the four national ministries and commissions is: natural gas distributed energy refers to the use of natural gas as fuel to realize the cascade utilization of energy through the combined cooling, heating and power supply, Modern energy supply mode with comprehensive energy utilization efficiency of more than 70% and energy supply nearby the load center is an important way for efficient utilization of natural gas

in the national power industry standard code for design of gas fired distributed energy supply stations (dl/t) issued by the National Energy Administration in 2015, the definition of distributed energy supply system is: an energy supply system that is arranged near users, uses natural gas and other primary energy as fuel, and directly outputs heat (cold) and electric energy to users through heat (cold) and electricity cogeneration

according to the national industry standard technical specification for gas-fired combined cooling, heating and power supply project (CJJ) issued by the Ministry of housing and urban rural development in 2010 and the national standard technical specification for gas-fired combined cooling, heating and power supply project (GB) jointly issued by the Ministry of housing and urban rural development and the General Administration of quality supervision, inspection and quarantine, the gas-fired combined cooling, heating and power supply system is defined as: it is arranged near the user, uses gas as the primary energy for power generation, and uses the waste heat of power generation for cooling and heating, At the same time, the distributed energy supply system will generate friction between the hot (cold) working piston and the working cylinder that output electric energy to users

among the above statements, the definition and content of natural gas distributed energy in the guiding opinions on the development of natural gas distributed energy are more recognized. The natural gas distributed energy realizes the local consumption of secondary energy in the load center by means of "combined cooling, heating and power supply", especially the three secondary energy products of cooling, heating and electricity, which realize the cascade utilization of energy, rather than one or two, The system that only realizes one or two kinds of secondary energy can not be called as natural gas distributed energy

second, the natural gas distributed energy industry has its own problems. Some employees deliberately confuse the concept out of their own interests. They clearly developed the gas-fired cogeneration project, but they chose to borrow the name of the natural gas distributed energy project. The reason is also very simple. The state has a clear support policy for the natural gas distributed energy, but there is no clear support policy for the gas-fired cogeneration, Therefore, these people have adopted the technique of grafting flowers and trees, and intentionally carried out gas-fired cogeneration under the banner of natural gas distributed energy

from a professional perspective, what is the difference and connection between natural gas distributed energy and gas-fired cogeneration? We consulted the relevant materials in order to clarify the relationship between the two

in my opinion, there are "ten differences" between natural gas distributed energy and gas-fired cogeneration:

first, the definitions are different

according to the above point of view, the definition of natural gas distributed energy is expressed in the guiding opinions on the development of natural gas distributed energy issued by the four national ministries and commissions, "Natural gas distributed energy refers to a modern energy supply mode that uses natural gas as fuel, realizes the cascade utilization of energy by means of combined cooling, heating and power, etc., with a comprehensive energy utilization efficiency of more than 70%, and realizes energy supply nearby the load center. It is an important way for the efficient utilization of natural gas. Compared with the traditional centralized energy supply mode, natural gas distributed energy has the advantages of high energy efficiency, clean environmental protection, good security, peak shaving and valley filling , good economic benefit, etc

for the definition of cogeneration, refer to the revised provisions on the development of cogeneration issued by the national development and Reform Commission on June 30, 2011 (Order No. 10 of the national development and Reform Commission in 2011) and the management measures for cogeneration issued by the national development and Reform Commission, the national energy administration, the Ministry of finance, the Ministry of housing and urban rural development, and the Ministry of environmental protection in 2016 (fgny [2016] No. 617), Unfortunately, there is no definition of cogeneration in the two government documents. After a lot of hard work, I finally found the relevant explanation in the revised version of the industry terminology standard "heating Terminology Standard" (cjj/t) issued by the Ministry of housing and urban rural development in 2011. The "heating Terminology Standard" mentioned that "cogeneration refers to the joint production mode in which thermal power plants produce electricity and available heat at the same time."

second, the secondary energy products produced by the two are different

natural gas distributed energy mainly includes three kinds of secondary energy products: cold, heat and electricity. The emphasis is on "temperature matching and cascade utilization", that is, to make full use of energy, make maximum use of energy and avoid energy waste. Cogeneration only requires heat and electricity, and the concept of cogeneration in the standard of heating terms only refers to electric energy and heat energy. At the same time, according to the revised provisions on the development of cogeneration issued by the national development and Reform Commission on June 30, 2011 (Order No. 10, 2011 of the national development and Reform Commission), "during the planning of cogeneration projects, it is necessary to actively develop urban hot water supply and centralized cooling, expand the cooling load in summer and improve the annual operation efficiency". The article clearly distinguishes cogeneration projects from hot water supply and centralized cooling. It can be seen that cooling can also be used as a sign to distinguish gas-fired cogeneration and natural gas distributed energy (Note: it is not the only sign)

third, the technical indicators required by the state are different

the national indicator for natural gas distributed energy is the comprehensive energy utilization rate, while the technical indicator for cogeneration project is the thermal power ratio

in the guiding opinions on the development of natural gas distributed energy, it is required that "the comprehensive energy utilization efficiency shall be more than 70%" for natural gas distributed energy

according to Article 7 of the revised provisions on the development of cogeneration issued by the national development and Reform Commission on June 30, 2011 (Order No. 10 of 2011 of the national development and Reform Commission), the annual average total thermal efficiency of conventional cogeneration with both power generation and heat supply by steam flow of heating turbine generator units shall be greater than 45%, and the annual average thermal power ratio of thermal power units with a unit capacity of less than 50MW shall be greater than 100%, For thermal power units with a unit capacity of 50MW to 200MW, the annual average thermal power ratio shall be greater than 50%; for units with a unit capacity of 200MW or more, the thermal power ratio shall be greater than 50% during the heating period; The gas steam combined cycle cogeneration system includes: the annual average total thermal efficiency of the gas steam combined cycle cogeneration system (gas turbine + heat supply waste heat boiler, gas turbine + waste heat boiler + heat supply steam turbine) shall be greater than 55%, and the annual average thermal power ratio shall be greater than 30%

it can be seen that the national requirement for the comprehensive energy utilization rate of natural gas distributed energy is not less than 70%, while the maximum total thermal efficiency required for the cogeneration project is only 55%, which is quite different. (Note: total thermal efficiency = (heat supply + power supply) × 3600 kJ/kWh)/(total fuel consumption × Fuel unit low calorific value) × 100%, thermal power ratio = heat supply/power supply × 3600 kJ/WH) × 100%)。

fourth, different operation modes

the operation modes of natural gas distributed energy projects are more flexible and diverse. There are three operation modes: isolated operation, parallel operation and upper operation. Among them, natural gas distributed energy pays more attention to spontaneous self use and residual power

the cogeneration project is no different from the traditional thermal power project. It is basically an all-round mode (except for the self-contained cogeneration project). Except for the auxiliary power, most of the rest is transmitted to electricity

fifth, the location of the project is different

natural gas distributed energy is closer to the energy demand side, that is, the user demand side. It is required to be consumed nearby, and the power consumption is mainly for enterprises' own use (the State encourages enterprises to build their own distributed energy stations). According to the national power industry standard code for design of gas fired distributed energy supply stations (dl/t) issued by the National Energy Administration in 2015, the cooling radius is less than or equal to 2 km, the steam supply radius is less than or equal to 5 km, and the hot water heating radius is less than or equal to 10 km

cogeneration projects tend to be regional and serve the heat consuming enterprises in the whole region, with a wider service area. According to the management measures for cogeneration of heat and power (fgny [2016] No. 617) issued by the national development and Reform Commission, the National Energy Bureau, the Ministry of finance, the Ministry of housing and urban rural development, the Ministry of environmental protection and other five ministries and commissions in 2016, "For cogeneration units with hot water as the heating medium, the heating radius is generally considered as 20km. For cogeneration units with steam as the heating medium, the heating radius is generally considered as 10km"

sixthly, the installed scale and unit installed cost are different

it is generally recognized in the industry that the gas distributed energy project has a small single gas turbine with multiple gas turbines. The scale of the single gas turbine is less than 30000 kW, mostly less than 15000 kW, and the total installed capacity is generally not more than 50 MW. And burn

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