Mention intelligent buildings, we may first think of is the use of a variety of advanced intelligent equipment coupled with the network, broadband is the intelligent building of the building. In fact, this way we often overlook the most important green intelligent building is the most should first consider the issue of building energy efficiency.
Intelligent building must first of all have low energy consumption, high comfort, followed by intelligent building equipment, information modernization and security, security and intelligence.
With the progress of human society, the issue of energy has become increasingly prominent. The human dependence on energy is getting higher and higher, and the energy consumption is also growing. The rapid growth of energy consumption is an important symbol of human progress. However, it has also caused serious damage to the environment in which human society depends for survival. Therefore, energy and the environment are the foundation and key to ensuring the sustainable development of human society and are also the hot issues of general concern in today's world. However, compared with the world average, only 55% of coal, 11% of oil and 4% of natural gas are used per capita in China. Imports of oil in 2000 accounted for 33% of the total oil consumption. According to this rate by 2020, the proportion of imported oil and gas may reach more than 50% of the total oil consumption. Per capita energy resources occupy a low volume, making this issue even more important. With the advent of our climax of urbanization, the annual new urban construction area of â€‹â€‹about 1 billion square meters. At present, China's building energy consumption accounts for about 28% of total energy consumption. Reduce energy consumption, building energy conservation bear the brunt. How to improve the level of energy use, reduce the pollution caused by energy consumption to the environment, and improve our living environment has become an urgent and hard task. Only using non-traditional high-tech environmental energy technologies can effectively solve the serious pollution caused by energy consumption on the environment. Heat pump technology is such a typical environmental energy technology.
Heat pump is not only an advanced energy supply equipment and technology, but also an effective solution to the problem of human over-consumption of energy based on the principle of thermodynamics. In a sense, it can be said that heat pump is our human "second energy ".
This is because, according to thermodynamics, a heat pump is the only thermodynamic device that draws energy from the environment by consuming a certain amount of high-grade energy (electrical energy) and enhances its taste for people to use. The "energy" in the environment is infinite. In addition, many low-grade renewable energy environments (atmospheric, surface and earth) and waste heat from urban wastewater, and so on, are renewable energy sources that can only be efficiently utilized by heat pumps. The main advantages are as follows:
(1) Energy-saving: Compared with direct electric heating, energy-saving more than 70%; gas, fuel heating compared to save operating costs more than 50%.
(2) Environmental protection: heat pump itself has no combustion process, there is no emissions of combustion products;
(3) a machine with three, winter heating, summer cooling, but also throughout the year for domestic hot water.
(4) save primary energy and provide means for the utilization of renewable energy.
Because of this remarkable feature, the heat pump technology is an air-conditioning system with heat pump technology that can significantly reduce the energy consumption while solving the heating and cooling supply of the building. The development of renewable energy using heat pump technology is bound to become energy-saving in buildings Important means.
At present, our application of heat pump technology, air-conditioning systems are air-source heat pump air-conditioning system, water ring heat pump air conditioning system, ground source heat pump air conditioning system. Because of its energy sources and the use of different ways, the effect of energy-saving are also different, including air-source heat pump system due to outdoor climate change, energy-saving effect than water ring heat pump central air conditioning system and ground source heat pump central air conditioning system Poor, ground source heat pump central air conditioning system can effectively use renewable energy and become the most energy-efficient central air conditioning system. This article only on the most energy-efficient ground source heat pump central air conditioning system for further introduction.
Ground source heat pump Central air conditioning is a heat pump technology using shallow shallow geothermal resources can both heating and cooling of high efficiency energy-saving air-conditioning system. Ground source heat pump by entering a small amount of high-grade energy (such as electricity), to achieve low-temperature heat transfer to high temperature. In winter, respectively, as a heat pump heat source and the summer air-conditioning cold source, that is, in winter, the heat to "take out" to increase the temperature, the supply of indoor heating; Summer, the indoor heat removed, release To the ground can go.
Shallow geothermal resources are found extensively in the soil and groundwater in shallow temperate (within a few hundred meters) of the ground. The energy source of shallow ground (heat) is mainly solar energy. It is a low grade (25 â„ƒ) renewable energy. Different from the traditional deep (5km) geothermal energy.
It is basically free from geographical and climatic influences. Its relatively constant temperature, huge reserves, is a new energy that should not be overlooked. In building heating (cold) with new energy is the most realistic, most economical and most promising energy. Shallow low temperature can exist widely in the temperate zone near the surface of the earth, its temperature is slightly higher than the local average annual temperature of about 3 â„ƒ, in different regions and different climatic conditions, the temperature in the temperate zone does not change, relative Stable, the so-called low temperature is that it is lower than the traditional temperature of the hot spring (25 â„ƒ). North and south of the earth, its summer, winter, autumn and winter temperatures generally in the 10 â„ƒ ~ 25 â„ƒ range.
Ground source heat pump air conditioning system to take well and buried underground heat exchanger and other different ways to carry and extract shallow geothermal resources, precisely because of such a stable source of energy, usually source heat pump consumes 1kW of energy, the user can get 4kW above the heat or cold. So that its operating costs compared with the traditional central air-conditioning only 50 to 60% of its.
According to ground source heat pump air conditioning system to take the energy in different ways can be divided into open well type underground water source heat pump system and closed buried pipe-type ground source heat pump.
Groundwater source air conditioning heat pump system is extracted from the wells of groundwater. The heat-exchanged groundwater is recharged through the recharge wells to the groundwater layer. However, such a system requires a rich and stable groundwater resource as a prerequisite. And underground pumping out of the water after the heat exchanger is difficult to be fully recharged into the aquifer, easily lead to the loss of groundwater resources. Even if all the groundwater extracted can be fully recharged, there are still some problems, such as how to ensure that the groundwater layer is free from pollution, and whether it will cause quicksand collapse. The groundwater heat pump system has many limitations.
The ground-source heat pump air-conditioning system is through the circulation of liquid (water or water as the main component of the antifreeze) in a closed underground pipe flow, to achieve heat transfer between the system and the earth. During the heating process in winter, the fluid collects heat from the ground and brings it to the room through the system. The system operates in reverse during summer cooling, which takes the heat away from the room and sends the heat to underground soil through the system.
As a result, underground coupled heat pump systems maintain the advantages of groundwater heat pumps that use the earth as a source of heat and heat, without the need to extract groundwater as a means of heat transfer. Is more advanced, more broad prospects for the application of ground source heat pump. Ground source heat pump is the main direction of development. It is a truly sustainable new technology for building energy efficiency. Is gradually becoming the main body of ground source heat pump air conditioning system. Its main features are as follows:
1. Efficient, energy-saving The system's operation, the energy input and output ratio, up to 1: 4 or more. Heat dissipation in summer with high temperature difference and heating in winter with low temperature difference make the heat exchange efficiency of this system very high. So produce the same cold, heat when the power consumption is relatively low.
2. Environmental protection zero pollution does not require any form of boiler, cooling tower and other equipment, there is no coal, oil and natural gas emissions such as combustion emissions. Underground pipeline closed, circulating fluid without any pollution of groundwater may. No outdoor unit does not produce unpleasant heat island effect.
3. Safe and reliable The system equipment life of up to 15 years, the device performance and stability. No explosion or burning hazards, underground heat exchanger using high-density polyethylene plastic pipe, life expectancy of up to 50 years. Equipment maintenance simple, low cost. Underground heat exchanger under normal conditions without maintenance.
4. Simple structure, a multi-purpose system is simple and clear, easy to match with the construction equipment, no outdoor machine parts, to keep the appearance of the building beautiful, without defrosting. A set of units to achieve cooling, heating without any other auxiliary heat source. And according to user needs to provide hot water, in the summer conditions of refrigeration can be completely free to enjoy.
5. Low operating costs The system is efficient, energy-saving features that determine its lower operating costs. Its minimal depreciation and maintenance costs are significantly lower than traditional air conditioning. Its cooling and heating costs only 40% to 70% of the cost of traditional air-conditioning cooling and heating. Cost savings can make short-term recovery of investment.
6. Flexible layout, simplified by people Ground source heat pump system has a variety of implementations, heat pump equipment water - water-type units and water-wind units. And according to the different needs of the overall or split-type equipment. Layout is very flexible. And in accordance with the requirements of users from the most simple (starting and stopping, heating, cooling third gear) to the whole intelligent control.
In the past decade or so, especially in the past five years, ground-source heat pump air-conditioning systems have achieved rapid development in North America such as the United States, Canada, Central and Northern Europe such as Switzerland and Sweden, and their products and technologies have been quite mature. In 1998, the U.S. Department of Energy issued a regulation requiring the popularization and application of a ground-source heat pump air-conditioning system in the buildings of federal agencies across the country. To show its support for this energy-saving and environmentally friendly new technology, U.S. President Bush installed this ground-source heat pump air-conditioning system in his Texas home. The Canadian government has also introduced government subsidies to enjoy 25% of its construction cost in public buildings that use ground source GSHP systems in their country.
In our country, the importance of ground source heat pump air conditioning technology for building energy efficiency has been highly recognized and rapidly developed. In the "Catalog of Guidebooks for Promoting and Translating Scientific and Technological Achievements and Transformations of the Ministry of Construction in 2003", an energy-saving soil heat exchanger ground source heat pump Cold (hot) water supply technology as the second type of building energy-saving technology in the first (2003014). Because of its energy-efficient, environmentally friendly non-polluting, stable system operation, a wide range of applications with a wide range of products, technology is mature and so difficult to replace the advantages: will become the real twenty-first century green air-conditioning system.
In summary, we can easily see that the use of heat pump technology, which is the ground source of ground source heat pump air conditioning green air conditioning system, will greatly reduce the air conditioning brought by the building energy consumption, which has become a truly intelligent building Important means.