\N nTime: June 15, 26 18: 24 Source: China Electromechanical Enterprise Network
Ground-source heat pump is actually a very old technology, which was applied in the forties, but it has been commercialized rapidly with the development of related technologies in recent five years. The name of ground source heat pump first appeared in a patent document in Switzerland in 1912, and the first climax of using ground source heat pump appeared in Europe in the 195s. During this period, Ingersoll and Plass put forward the linear heat source theory of underground heat exchanger according to Kelvin's linear source concept, but it was not widely used at that time because of the low energy price and high system cost. In 197s, the oil crisis focused people's attention on energy saving and efficient use of energy, which made the development of ground source heat pump enter a climax stage. At this time, the underground buried pipe has been changed from the early amount pipe to the plastic pipe. During this period, many ground source heat pumps with horizontal buried heat exchangers were established in Europe, but they were mainly used for heating in winter. Since the early 198s, the United States and Canada have carried out research work on ground source heat pumps with combined cooling and heating. Many literatures have reported the heat transfer process and models of different underground heat exchangers of ground source heat pumps, and some projects have summarized their operation and compared their performance.
both the U.S. department of energy (DOE) and the U.S. environmental protection agency (EPA) have confirmed that the ground source heat pump system is the most efficient and environmentally friendly hot water, heating and refrigeration system at present. On the one hand, it makes use of the relatively stable temperature of underground soil or rock to keep the heating and air conditioning system running efficiently all year round, saving 2-5% electricity for ground source heat pump users.
from the calculation results of some literatures, it can be seen that the efficiency ratios of multi-zone headwind system, single-zone headwind system, cold water to wind system and multi-zone ground source heat pump system are 1.54kw/ton, 1.4kw/tom, 1.23kw/ton and .88kw/ton, respectively, where kw/ton represents kilowatt power consumption/ton of refrigeration capacity. It can be seen that the efficiency ratio of ground source heat pump system is the best compared with traditional air conditioning.
On the other hand, under the same conditions, buildings with ground source heat pump systems can reduce maintenance costs. Ground source heat pump is very durable, and its mechanical moving parts are very few. All the parts are either buried underground or installed indoors, thus avoiding the harsh outdoor climate. The underground part can be guaranteed for 5 years, and the aboveground part can be guaranteed for 3 years. Therefore, ground source heat pump is a maintenance-free air conditioner, which saves the maintenance cost and enables the user's investment to be recovered in about three years. The maintenance cost of air conditioning system was investigated in Lincoln City and Nebraska and 2 schools. These 2 schools adopted four different cooling modes: ground source heat pump system (GHP), air cooler with hot water boiler (ACC/GHWB), water cooler with hot water boiler (WCC/GHWB) and water cooler with steam boiler (WCC/GSB). .
in Atlanta, the annual cost of air-cooled heat pump system, common air conditioning system and ground source heat pump system is $826, $686 and $397 respectively. It can be seen that the operating cost of ground source heat pump system is quite low compared with other air conditioning systems.
more importantly, the refrigerant used in the ground source heat pump system is injected in the factory and completely sealed, so there is no leakage during use, and users do not need to replenish refrigerant at any time, thus reducing the damage to the ozone layer. The system can be used in residential buildings with different structures and areas, can be installed in the construction of new buildings, and can also be used in the renovation of old buildings. Its flexibility in design makes it a very attractive air conditioning choice. Ground source heat pump has special advantages in dehumidification, so it is very suitable for hot and humid climate in summer. If air conditioner is added to air distribution device, the characteristics of ground source heat pump will be more prominent, so if indoor air quality standards are to be met, ground source heat pump system is also a very good choice.
Ground source heat pump has the above advantages, such as government offices, apartments and restaurants. According to the user survey conducted by Oklahoma Electric Power Company in red river valley, 99% of the users of ground source heat pump air conditioners scored more than 8 points for their cooling capacity in summer, and 73% scored 1 points out of 1. 21-1-14 9:6: Source: Tianjin Net-Tianjin Daily (Tianjin)
Geothermal water is used in agricultural production, which reduces the use of coal
The first snow in the New Year has caused the outdoor temperature in this city to drop suddenly. However, the workshop of Xinmao New Energy and New Materials Industrial Base is as warm as spring, and the thermometer hanging on the wall clearly shows the indoor temperature of 23℃. "We are heating here, neither burning coal nor gas, not to mention traditional air conditioning. Can you guess what to use?" When I saw the reporter, Li Dechun of Xinmao Base sold a pass first, and then stamped his foot gently. "It is the land under our feet, which can not only warm up, but also cool down, and is vividly called' geothermal air conditioning' by us."
Li Dechun's "geothermal air conditioning" is accurately called "ground source heat pump", which is a new type of central air conditioning system that does not burn oil, gas or coal. According to Yu Weifeng, general manager of Tianjin Fengshang Electromechanical Co., Ltd., a technology provider, the temperature of shallow soil on the surface is relatively stable all year round, and the temperature difference with air is generally about 17℃, and the underground soil temperature is really warm in winter and cool in summer. According to this characteristic, in winter, the heat in the stratum can be "extracted" through certain equipment and technology, and after the temperature is raised, it can be supplied to indoor users for heating, on the contrary, it can achieve the purpose of refrigeration in summer.
As an industrial base with a building area of 35, square meters, heating and cooling are not small expenses. Xinmao New Energy and New Materials Base once asked relevant technicians to calculate an account. Based on the heating area of a single unit of 7, square meters, municipal heating in winter and screw mechanism cooling in summer were adopted. The hardware investment in the early stage was 2.55 million yuan, and the annual operating cost was 357, yuan. However, Xinmao's 35, square meters area exceeded 16 million yuan in one year.
The huge cost forced Xinmao to abandon the traditional heating and cooling methods and adopt ground source heat pump instead. Geothermal energy contained in shallow soil is widely distributed, renewable, huge in reserves, low in access cost, and more importantly, it is a clean energy source. After one year's operation, Li Dechun has felt the advantages of ground source heat pump in many aspects. The most direct benefit is the low operating cost of ground source heat pump. Energy saving and emission reduction does not mean high investment, which is closely related to the reduction of production cost. Based on the heating and cooling area of a single unit of 7, square meters, the hardware investment of the ground source heat pump is 1.96 million yuan, and the operating cost is 21, yuan. In one year, the entire base of 35, square meters is only 1 million yuan, saving 6 million yuan at once. It can reduce carbon dioxide emissions by 75 tons. "Don't underestimate this system, which is equivalent to planting 12 trees more than one year."
not only in xinmao, but also in many enterprises, industrial parks, schools and residential areas in this city. Since 28, this city has been listed as one of the three pilot cities of ground source heat pump air conditioning system in China. At present, the construction area of Tianjin Port Bonded Area using ground source heat pump for heating has reached more than 8, square meters, accounting for about 16% of the total construction area of the bonded area. It can save about 12, tons of coal and reduce 28, tons of carbon dioxide emissions throughout the year, which is at the national leading level. Tianjin Mansion adopts the primary sewage source heat pump air conditioning system, which realizes the triple supply of cooling, heating and domestic hot water, conducts the soil heat through the sewage in the closed pipe, and turns the sewage into treasure, which has been identified as a demonstration project of renewable energy building application by the Ministry of Housing and Urban-Rural Development and the Ministry of Finance. According to estimates, heat pump heating saves about 4% coal compared with coal-fired heating. Every ton of sewage used is equivalent to at least 2 kilograms of coal burning. Tianjin Mansion uses 4, tons of sewage every year, saving about 8 tons of standard coal and reducing carbon dioxide emissions by 2,4 tons. (This article Source: Tianjin Daily) 21-1-15 14:52 Source: dalian tian jian Network
Heating is the biggest livelihood issue in the current society, and the cold is testing the administrative ability of the government. For urban fringe areas and rural areas, even if the urban heating pipe network is installed, the energy loss caused by the heating distance is quite huge. So, how to explore a heating mode in the "low carbon era"? Liu Chuntang, a member of the Committee, suggested that the ground source heat pump should be adopted and the relatively constant temperature groundwater should be recycled for heating, so as to realize energy saving and emission reduction.
investigation: the heat loss of the heating pipeline is serious
the heat loss is serious, resulting in waste. Liu Chuntang told reporters that the most common heating problems are those old houses heated by small boilers. "There are many problems in the corridors of these old houses, and the heat loss of heating pipes is serious." Through investigation, Liu Chuntang found that some of the corridors in abandoned residential areas and old houses have incomplete windows, some have wooden corridor doors, and some even have no corridor doors. Because many heating pipes are exposed outside, the heat has not yet entered the residents' homes, and a large part has been lost from the corridors.
Advantages: geothermal heating is pollution-free
"This' geothermal' is actually ground source heat pump heating." Liu Chuntang said that the ground source heat pump is an efficient and energy-saving air-conditioning system that uses shallow underground geothermal resources to provide heat and refrigeration, and can be widely used in commercial buildings, public buildings, residential apartments, schools, hospitals and other buildings. One of the advantages of geothermal heating is environmental protection, no emission of nitrogen oxides, sulfur dioxide and smoke, and no pollution. At present, geothermal heating has been tried in Beijing and other places, and the effect is good.
Status quo: Geothermal development in rural areas is not ideal
"Ground source heat pump technology is recognized by more and more people because of its advantages of environmental protection, energy saving and cleanliness, and simple control equipment. But in fact, the development of ground source heat pump technology in rural areas of China is very unsatisfactory. " Liu Chuntang said that the energy consumption of rural households in our city has basically completed the transformation from primary energy to commodity energy.
Liu Chuntang found in the survey that the average annual coal consumption of rural households around Beijing is 2.9 tons, electricity consumption is 92kW/h, and 3 ~ 4 tanks of liquefied gas are used. In the total household energy consumption, coal accounts for 74%, electricity accounts for 13%, liquefied gas accounts for 8%, and biomass energy such as straw accounts for only 5%. Of the 2.9 tons of coal consumed by rural households, 2.3 tons are used for heating, accounting for nearly 8%. According to the heat conversion, about 6% of household energy consumption is used for heating in winter, and 78% of households think that the heating burden is heavy. The energy consumption in rural areas around Dalian is basically the same as that in Beijing.
In view of the problems encountered in the promotion of geothermal energy in rural areas, Liu Chuntang said that the main reason is that the initial investment of ground source heat pump system is high, and the cost per square meter of single-type houses is usually around 35 ~ 4 yuan, and the cost per square meter of centralized buildings is usually around 15 ~ 2 yuan, which has caused the situation that rural residents can't afford to use it; At the same time, the thermal insulation measures of rural buildings are generally not good, resulting in large heat loss, which in turn leads to large heating load and high operating costs; In addition, at present, water and ground source heat pump systems are mostly used in public buildings, so professional and technical personnel are involved in the use of the system. However, when it is used by ordinary households, especially rural households, it will inevitably lead to mistakes in operation and even damage to the system.
suggestion: give residents subsidies according to heating area
Liu Chuntang told reporters that to solve the problem, we should set up professional institutions or instruct professional departments to conduct unified planning and research on energy technologies implemented in rural and urban fringe areas of our city, and come up with implementation plans, schemes and policies. Or take out certain areas and plots for demonstration; Give preferential land price and supporting facilities to development units that use geothermal energy and new energy technologies in urban fringe development projects or rural homestead renovation projects; At the same time, the heating cost of residents remains unchanged; Farmers who use ground source heat pumps in rural areas of our city in homesteads and greenhouses will be given certain subsidies according to the investment amount or heating area compared with the policy of home appliances going to the countryside.
In addition, because rural users spend most of their heating time at night, it is hoped that the relevant government departments can consider introducing a policy of giving rural users the same peak-valley electricity price as urban users. And give corresponding preferential and encouraging policies to the design, distribution and construction units that implement local energy and new energy technologies. good