1. Development Prospects of Gas Boilers
In recent years, the annual coal consumption in Shenyang has remained above 10 million tons. Among all coal-fired equipment, coal-fired boilers consume the most coal and are the biggest culprits of air pollution. Especially in winter, due to the extensive use of coal-fired boilers, the emissions of sulfur dioxide and other pollutants during the annual heating period are much higher than in other seasons. In order to return a blue sky to the people of Shenyang City, the Shenyang Municipal Government has made up its mind to control coal-fired boilers and has stipulated that new coal-fired boilers are prohibited within the urban second ring road, and the original coal-fired boilers must be phased out in batches. Switch to cleaner fuels. Therefore, as an emerging product, gas boilers with high quality, high efficiency and outstanding environmental benefits have entered the market. Shenyang Lu Xun Academy of Fine Arts completed the transformation of gas boilers to replace coal-fired boilers before the heating period in 2000 and has been put into use. The Liaoning Provincial Party Committee also connected the medium-pressure gas pipelines from the city streets to the hospital, preparing to complete the transformation of its four 10-ton coal-fired boilers in 2001. With the passage of time and the further enhancement of urban environmental awareness, gas boilers will surely provide a broad development space.
2. Gas source situation
The promotion and application of gas boilers must be guaranteed by sufficient gas resources. In the past, due to national energy policies, the utilization of the gas market was greatly restricted. In recent years, Shenyang City was once troubled by the problem of insufficient gas sources. A small amount of gas sources were given priority to civilian use, and it was impossible to vigorously develop gas boilers. Up to now, there are only more than 30 gas boilers in use in Shenyang City. Shenyang Gas Corporation has done a lot of practical work in the introduction of gas sources and has achieved results. Drilling wells to exploit shallow natural gas in the Shenxi area has been successful, and the average daily supply has reached about 80,000 cubic meters. The mine gas diverted from Fushun to Shenyang has been put into operation in the city pipeline network after being mixed with liquefied gas. Moreover, the Municipal Gas Corporation is actively embarking on a development cooperation project for coalbed methane in the Tiefa Coalfield, introducing coalbed methane gas from the Tiefa Coalfield, and has made progress. With the exploitation and introduction of the above-mentioned gas sources, Shenyang will have sufficient gas in the future to solve the gas source problem of gas-fired boilers.
3. Selection of gas boilers and gas supporting facilities
1. Gas pipelines, pressure regulating metering and alarm facilities
The gas source for the development of gas boilers must be taken from the city's medium-pressure pipelines. The reason is that the operating pressure of Shenyang's low-pressure pipe network (about 2X10 3Pa) cannot meet the inlet pressure required by the burner. The operating pressure level of Shenyang's medium-pressure pipeline network is medium pressure B. At this stage, according to the actual operation conditions of the urban medium-pressure pipeline network, the static pressure range of the burner inlet that can be provided after pressure regulation is (5-10)X10 3Pa.
The pressure regulating equipment selected for gas boilers is generally a secondary pressure regulator. The secondary pressure regulator of the second group is composed of a main pressure regulator and various ancillary accessories. The selection of Zhongyizhong voltage regulator refers to the selection of the crystal brand, model and caliber of the main voltage regulator. The main voltage regulator crystal brands are generally foreign brands. The more commonly used ones in Shenyang area are Tartarini from Italy; RMG from Germany; and Ulster from the United States. Each brand has multiple models, and each model is divided into different calibers according to flow rate. After the brand is selected, the model and caliber are selected first based on the pressure range of the inlet and outlet of the regulator, and secondly the output range of the burner.
After the gas is pressure-regulated, it must be measured before it can be put into use. The industrial measurement equipment currently used in Shenyang is the intelligent gas turbine flowmeter produced by Tianjin Xinke Complete Instrument Co., Ltd. The biggest advantage of this product is that it can accurately measure the volume of the gas medium while simultaneously tracking the temperature and pressure of the detected medium, and will use different The volume flow rate under working conditions is converted into the volume flow rate under standard push conditions (P=1.033X10 5Pa, T=293.15K), and is clearly displayed on the LCD screen.
After the gas is measured, the gas pipeline is connected to the burner's accessory accessories through a special gas valve. The burner accessory accessories include filters, solenoid valves, leak detection devices, gas butterfly valves, etc. When the output range of the burner is determined, that is to say, the hourly gas consumption is determined, the pressure of the gas and the caliber of the accessory accessories become contradictory. Within the allowable range of the burner inlet pressure, the higher the inlet pressure of the gas, the smaller the caliber of the accessory accessories. The lower the caliber, the more economical the price of the corresponding accessory accessories. Therefore, the caliber of the burner accessory accessories can be selected based on the inlet pressure of the medium pressure regulator provided by the medium pressure pipe network at the gas consumption point. Select a higher outlet pressure. to reduce its acquisition cost.
The boiler room also needs to be equipped with gas leak detection facilities. Once gas leaks, the alarm host will sound and light alarm, and the inlet gas can be cut off manually or directly by interlocking the electromagnetic cut-off valve.
2. Gas boiler and matching burner.
There are many brands of gas boilers, and many well-known foreign brands have also entered the domestic market. Burners are generally from foreign brands, the more well-known ones include Italy's Riello, Germany's Weishaupt and Zak; Japan's Olympia. The so-called burner matching the gas boiler means that the output power (output value) of the burner must match the heat supply of the gas boiler. For example, a 0.7MW gas boiler should choose a burner with an output range of about 0.7MW. Due to different brands of gas boilers and matching burners selected, prices will vary greatly.
The main basis for selecting a gas boiler model is the heating area and the thermal index of the city where it is located. To give a simple example: an office building in Shenyang has a heating area of 70,000 square meters, and the thermal index is estimated to be 100-110Kcal/h.m2. Try to select a gas boiler. First, calculate the required thermal power of the gas boiler to be 7-7.7 million Kcal/h.m2, and the converted total power value is about 8.4MW (1MW≈860,000Kcal). The gas boiler model is generally selected as 2.8MW, and the quantity is 4 units (three in operation and one in standby).
4. Operating costs
When a gas boiler is used for heating, the gas cost during the heating period is what the gas user is most concerned about. In fact, this value has great flexibility, and it is determined by many aspects such as climate, equipment, operating time and flight control technology. When the temperature drops, the operating time should be lengthened; if the equipment is good, the thermal efficiency will be high. Here we discuss it with two examples:
The boiler room of Shenyang Lu Xun Academy of Fine Arts uses three 4.2MW gas boilers produced by Chongqing Boiler Factory. The heating area is 120,000 square meters. The heating objects are old residential buildings and office buildings. The heating temperature is 18°C. During the heating period, 1.25 million cubic meters of gas will be used, and the gas fee will be 3 million yuan. The cost of gas per square meter is 25 yuan.
The boiler room of the civil servant community of Liaoning Provincial Government uses four 2.8MW French Gyou gas boilers, with a heating area of 120,000 square meters. The heating object is newly built residential buildings, and the heating temperature is 20°C. During the heating period, 127 cubic meters of gas are used, and the gas fee is 3.05 million yuan. The cost of gas per square meter is 25.4 yuan.
5. Several factors for the development of gas boilers
Cost factors: mainly initial investment costs and operating costs
(1) Initial investment cost
1. Gas boiler construction costs, the vast majority of winter heating facilities in Shenyang are coal-fired boilers. At this stage, the technical means to transform the coal-fired boiler body are not yet mature, so the only option is to replace the coal-fired boiler with a gas-fired boiler. This cost is prohibitive for large coal-fired boiler houses.
2. Gas boiler supporting equipment construction costs and construction costs. As mentioned above, the supporting equipment mainly includes pressure regulating equipment, metering equipment and burners. The purchase fee will vary depending on the brand. The most important construction cost is the gas pipeline laying cost, which is approximately 1.4 million yuan/km. At present, the medium-pressure pipelines in the streets of Shenyang are mainly concentrated on the first and second-level roads. Many interested users often give up because the gas consumption point is too far from the medium-pressure pipelines in the streets.
3. Gas pipeline network financing costs. The gas pipeline network financing fee is a co-ordinated fund collected by the municipal government from gas users. The charging standard for industrial households is the maximum daily gas consumption (m3) Very large, it is a crucial factor in the development of gas boiler users.
(2) Operating costs
The most important operating cost of a gas boiler during the heating period is the gas cost. The current sales price of gas in Shenyang is relatively high, and the heating costs of using gas are much higher than the heating costs of coal-fired heating companies. This limits the development space of gas boilers. At this stage, the development direction of gas boilers is mainly for heating office buildings of enterprises and institutions. The use of gas heating in residential areas still needs to be reduced by the reduction of gas prices and the introduction of relevant preferential policies.
Gas source factors: The development of gas boilers requires a large amount of gas sources. The current shortage of gas sources in Shenyang in winter has restricted the development of gas boilers.
Technical factors: With the use of gas boilers, the technical specifications and construction specifications related to them have matured, making the use of gas boilers safer and more reliable. Some projects that were not technically feasible had to be abandoned.
Unbalanced gas consumption factors: Gas boilers only consume gas during the heating period, and the gas consumption is huge. Its seasonal uneven gas consumption poses a considerable problem to the gas sales company.
To sum up, it can be clearly seen that the cost of heating with a gas boiler is higher than that of a traditional coal-fired boiler. However, gas boilers use clean fuel, which is beneficial to protecting the urban atmospheric environment. Although the current situation of China's gas market restricts the development of gas boilers in some aspects. But in the long run, the use of gas boilers for heating will be the trend in the heating industry in the future.
1. Development Prospects of Gas Boilers
In recent years, the annual coal consumption in Shenyang has remained above 10 million tons. Among all coal-fired equipment, coal-fired boilers consume the most coal and are the biggest culprits of air pollution. Especially in winter, due to the extensive use of coal-fired boilers, the emissions of sulfur dioxide and other pollutants during the annual heating period are much higher than in other seasons. In order to return a blue sky to the people of Shenyang City, the Shenyang Municipal Government has made up its mind to control coal-fired boilers and has stipulated that new coal-fired boilers are prohibited within the urban second ring road, and the original coal-fired boilers must be phased out in batches. Switch to cleaner fuels. Therefore, as an emerging product, gas boilers with high quality, high efficiency and outstanding environmental benefits have entered the market. Shenyang Lu Xun Academy of Fine Arts completed the transformation of gas boilers to replace coal-fired boilers before the heating period in 2000 and has been put into use. The Liaoning Provincial Party Committee also connected the medium-pressure gas pipelines from the city streets to the hospital, preparing to complete the transformation of its four 10-ton coal-fired boilers in 2001. With the passage of time and the further enhancement of urban environmental awareness, gas boilers will surely provide a broad development space.
2. Gas source situation
The promotion and application of gas boilers must be guaranteed by sufficient gas resources. In the past, due to national energy policies, the utilization of the gas market was greatly restricted. In recent years, Shenyang City was once troubled by the problem of insufficient gas sources. A small amount of gas sources were given priority to civilian use, and it was impossible to vigorously develop gas boilers. Up to now, there are only more than 30 gas boilers in use in Shenyang City. Shenyang Gas Corporation has done a lot of practical work in the introduction of gas sources and has achieved results. Drilling wells to exploit shallow natural gas in the Shenxi area has been successful, and the average daily supply has reached about 80,000 cubic meters. The mine gas diverted from Fushun to Shenyang has been put into operation in the city pipeline network after being mixed with liquefied gas. Moreover, the Municipal Gas Corporation is actively embarking on a development cooperation project for coalbed methane in the Tiefa Coalfield, introducing coalbed methane gas from the Tiefa Coalfield, and has made progress. With the exploitation and introduction of the above-mentioned gas sources, Shenyang will have sufficient gas in the future to solve the gas source problem of gas-fired boilers.
3. Selection of gas boilers and gas supporting facilities
1. Gas pipelines, pressure regulating metering and alarm facilities
The gas source for the development of gas boilers must be taken from the city's medium-pressure pipelines. The reason is that the operating pressure of Shenyang's low-pressure pipe network (about 2X10 3Pa) cannot meet the inlet pressure required by the burner. The operating pressure level of Shenyang's medium-pressure pipeline network is medium pressure B. At this stage, according to the actual operation conditions of the urban medium-pressure pipeline network, the static pressure range of the burner inlet that can be provided after pressure regulation is (5-10)X10 3Pa.
The pressure regulating equipment selected for gas boilers is generally a secondary pressure regulator. The secondary pressure regulator of the second group is composed of a main pressure regulator and various ancillary accessories. The selection of Zhongyizhong voltage regulator refers to the selection of the crystal brand, model and caliber of the main voltage regulator. The main voltage regulator crystal brands are generally foreign brands. The more commonly used ones in Shenyang area are Tartarini from Italy; RMG from Germany; and Ulster from the United States. Each brand has multiple models, and each model is divided into different calibers according to flow rate. After the brand is selected, the model and caliber are selected first based on the pressure range of the inlet and outlet of the regulator, and secondly the output range of the burner.
After the gas is pressure-regulated, it must be measured before it can be put into use. The industrial measurement equipment currently used in Shenyang is the intelligent gas turbine flowmeter produced by Tianjin Xinke Complete Instrument Co., Ltd. The biggest advantage of this product is that it can accurately measure the volume of the gas medium while simultaneously tracking the temperature and pressure of the detected medium, and will use different The volume flow rate under working conditions is converted into the volume flow rate under standard push conditions (P=1.033X10 5Pa, T=293.15K), and is clearly displayed on the LCD screen.
After the gas is measured, the gas pipeline is connected to the burner's accessory accessories through a special gas valve. The burner accessory accessories include filters, solenoid valves, leak detection devices, gas butterfly valves, etc. When the output range of the burner is determined, that is to say, the hourly gas consumption is determined, the pressure of the gas and the caliber of the accessory accessories become contradictory. Within the allowable range of the burner inlet pressure, the higher the inlet pressure of the gas, the smaller the caliber of the accessory accessories. The lower the caliber, the more economical the price of the corresponding accessory accessories. Therefore, the caliber of the burner accessory accessories can be selected based on the inlet pressure of the medium pressure regulator provided by the medium pressure pipe network at the gas consumption point. Select a higher outlet pressure. to reduce its acquisition cost.
The boiler room also needs to be equipped with gas leak detection facilities. Once gas leaks, the alarm host will sound and light alarm, and the inlet gas can be cut off manually or directly by interlocking the electromagnetic cut-off valve.
2. Gas boiler and matching burner.
There are many brands of gas boilers, and many well-known foreign brands have also entered the domestic market. Burners are generally from foreign brands, the more well-known ones include Italy's Riello, Germany's Weishaupt and Zak; Japan's Olympia. The so-called burner matching the gas boiler means that the output power (output value) of the burner must match the heat supply of the gas boiler. For example, a 0.7MW gas boiler should choose a burner with an output range of about 0.7MW. Due to different brands of gas boilers and matching burners selected, prices will vary greatly.
The main basis for selecting a gas boiler model is the heating area and the thermal index of the city where it is located. To give a simple example: an office building in Shenyang has a heating area of 70,000 square meters, and the thermal index is estimated to be 100-110Kcal/h.m2. Try to select a gas boiler. First, calculate the required thermal power of the gas boiler to be 7-7.7 million Kcal/h.m2, and the converted total power value is about 8.4MW (1MW≈860,000Kcal). The gas boiler model is generally selected as 2.8MW, and the quantity is 4 units (three in operation and one in standby).
4. Operating costs
When a gas boiler is used for heating, the gas cost during the heating period is what the gas user is most concerned about. In fact, this value has great flexibility, and it is determined by many aspects such as climate, equipment, operating time and flight control technology. When the temperature drops, the operating time should be lengthened; if the equipment is good, the thermal efficiency will be high. Here we discuss it with two examples:
The boiler room of Shenyang Lu Xun Academy of Fine Arts uses three 4.2MW gas boilers produced by Chongqing Boiler Factory. The heating area is 120,000 square meters. The heating objects are old residential buildings and office buildings. The heating temperature is 18°C. During the heating period, 1.25 million cubic meters of gas will be used, and the gas fee will be 3 million yuan. The cost of gas per square meter is 25 yuan.
The boiler room of the civil servant community of Liaoning Provincial Government uses four 2.8MW French Gyou gas boilers, with a heating area of 120,000 square meters. The heating object is newly built residential buildings, and the heating temperature is 20°C. During the heating period, 127 cubic meters of gas are used, and the gas fee is 3.05 million yuan. The cost of gas per square meter is 25.4 yuan.
5. Several factors for the development of gas boilers
Cost factors: mainly initial investment costs and operating costs
(1) Initial investment cost
1. Gas boiler construction costs, the vast majority of winter heating facilities in Shenyang are coal-fired boilers. At this stage, the technical means to transform the coal-fired boiler body are not yet mature, so the only option is to replace the coal-fired boiler with a gas-fired boiler. This cost is prohibitive for large coal-fired boiler houses.
2. Gas boiler supporting equipment construction costs and construction costs. As mentioned above, the supporting equipment mainly includes pressure regulating equipment, metering equipment and burners. The purchase fee will vary depending on the brand. The most important construction cost is the gas pipeline laying cost, which is approximately 1.4 million yuan/km. At present, the medium-pressure pipelines in the streets of Shenyang are mainly concentrated on the first and second-level roads. Many interested users often give up because the gas consumption point is too far from the medium-pressure pipelines in the streets.
3. Gas pipeline network financing costs. The gas pipeline network financing fee is a co-ordinated fund collected by the municipal government from gas users. The charging standard for industrial households is the maximum daily gas consumption (m3) Very large, it is a crucial factor in the development of gas boiler users.
(2) Operating costs
The most important operating cost of a gas boiler during the heating period is the gas cost. The current sales price of gas in Shenyang is relatively high, and the heating costs of using gas are much higher than the heating costs of coal-fired heating companies. This limits the development space of gas boilers. At this stage, the development direction of gas boilers is mainly for heating office buildings of enterprises and institutions. The use of gas heating in residential areas still needs to be reduced by the reduction of gas prices and the introduction of relevant preferential policies.
Gas source factors: The development of gas boilers requires a large amount of gas sources. The current shortage of gas sources in Shenyang in winter has restricted the development of gas boilers.
Technical factors: With the use of gas boilers, the technical specifications and construction specifications related to them have matured, making the use of gas boilers safer and more reliable. Some projects that were not technically feasible had to be abandoned.
Unbalanced gas consumption factors: Gas boilers only consume gas during the heating period, and the gas consumption is huge. Its seasonal uneven gas consumption poses a considerable problem to the gas sales company.
To sum up, it can be clearly seen that the cost of heating with a gas boiler is higher than that of a traditional coal-fired boiler. However, gas boilers use clean fuel, which is beneficial to protecting the urban atmospheric environment. Although the current situation of China's gas market restricts the development of gas boilers in some aspects. But in the long run, the use of gas boilers for heating will be the trend in the heating industry in the future.