Technical paper on air conditioning energy saving 1 Discussion on air conditioning energy saving technology
In recent years, with the continuous development of social economy, people's quality of life has gradually improved, and the requirements for material life and environmental comfort have become higher and higher. Obviously, air conditioning system has become an indispensable part of modern construction industry. However, in recent years, the prominent energy crisis and the gradual deepening of environmental damage have made people clearly realize the importance of environmental protection and energy conservation, and the state has also formulated a series of laws, regulations and industry standards. Therefore, it has become an important topic to study the methods and technologies to effectively save energy and improve the effective utilization rate of energy. Based on the key factors affecting the energy consumption of air conditioning system, this study puts forward several feasible energy-saving schemes for air conditioning, and finally discusses the development trend of energy-saving for air conditioning in the future.
Keywords: air conditioning system; Energy-saving technology; Measures and suggestions
China Library Classification Number: TU83 1.3+5 Document Identification Number: A.
Foreword:
With the continuous improvement of people's economic level and quality of life, air conditioning systems are more and more widely used in modern buildings, both in living environment and working environment. According to statistics, the energy consumption of air conditioning in China accounts for 60% ~ 70% of the total energy consumption of buildings. Therefore, taking effective energy-saving measures to solve the energy-saving problem of high-rise buildings conforms to the requirements of China's sustainable economic development and is of great significance to energy conservation and emission reduction and building an environment-friendly society.
Present situation of air conditioning energy consumption and the importance of energy saving
With the gradual deepening of reform and opening up, the rapid development of national economy and the improvement of people's requirements for quality of life, air conditioning has been widely used in modern buildings. In building energy consumption, air conditioning energy consumption has accounted for about 60%~70% of building energy consumption, and this proportion is still rising year by year. Therefore, the development of air-conditioning energy-saving technology has an important impact on improving energy utilization and environmental sustainable development.
At present, in the application of central air conditioning system in China, it is generally considered that the temperature and humidity control and air quality control of air conditioning system are the most important, while the energy consumption of air conditioning system is ignored. In China, there are three main factors that affect the effective utilization of energy in central air conditioning system. First of all, the investment cost is emphasized in the design process, while the calculation of energy consumption index is ignored. In the whole system scheme, there is a lack of economic analysis of energy-saving oriented central air conditioning system. Therefore, in the operation process of the project construction scheme, the air conditioning system with low investment, high energy consumption and high operating cost is adopted. Secondly, for central air-conditioning, the whole system engineering is relatively complicated, so the evaluation of the effective utilization of energy of central air-conditioning should be viewed from the whole system, not simply from the machinery itself. The real energy saving is closely related to the design concept, construction quality, operation and management level of each system and the thermal characteristics of the building, rather than just paying attention to the equipment itself. Finally, there is a main factor, that is, the lack of high-quality operation management personnel and energy-saving monitoring, which leads to the air-conditioning system not being well controlled and supervised in the process of operation management. Qualified management personnel can greatly improve unreasonable operation and be conducive to energy saving.
Building energy-saving technology
The energy-saving technology of air conditioning system can start from the building itself, and combine the relevant knowledge of architecture and structure to make the building create the most basic conditions for air conditioning energy saving in terms of shape, color, orientation and materials. Reasonable arrangement of air conditioning position, reasonable design of relevant proportion and coefficient, selection of materials with good thermal insulation performance as wall and roof, and improvement of the performance of building envelope are all feasible building energy-saving measures.
2. 1 Select reasonable interior design parameters.
In the whole building, the main heat loss comes from the air infiltration in the envelope and the cracks in the doors and windows. Therefore, in building energy conservation, attention should be paid to strengthening the envelope in indoor design and using environmentally-friendly and energy-saving building materials, which can effectively reduce the heat transferred through the envelope, which is the main load of air conditioning, and make the capacity of main equipment achieve remarkable energy-saving effect. In this way, heat preservation is carried out, and the air tightness of doors and windows is strengthened. In addition, when air-conditioning is used for refrigeration in summer, indoor and outdoor glass is exposed to sunlight, which is the main part of air-conditioning cooling load, so necessary sunshade measures should be taken. In winter, when air conditioning provides heat, it is required to improve the insulation effect of windows, and glass with good photothermal performance can be used; In order to reduce the cold (hot) bridge heat transfer of windows, steel-plastic windows can be used instead of aluminum alloy windows; At the same time, double glazing can be used to improve the thermal insulation of windows. In the design position of windows, it is beneficial to reduce the area ratio of window opening to wall, the area of external wall with large temperature difference on both sides of air-conditioned room and the area of weak link window.
2.2 Reasonable design of building structure
Reasonable design of building structure is also one of the effective ways to save energy in air conditioning. By improving the thermal insulation performance of the building, the indoor cold and heat loss can be transferred through the walls, doors and windows of the room, which can effectively reduce the cold and heat load of the building. Building orientation has a great influence on the cooling load of air conditioning. According to the geographical position of our country, it is necessary to analyze and determine a good architectural orientation for building energy conservation in our country. By maintaining reasonable building spacing and scattered layout of buildings, buildings can receive appropriate solar radiation and are conducive to obtaining natural ventilation airflow.
Energy saving in air conditioning design
In a large air-conditioned room, the load in the inner area of the air-conditioned room is quite different from that in the surrounding area. If two areas choose to use an air conditioning system for refrigeration, there will be a large temperature difference between rooms in two air-conditioned rooms, especially in winter and transitional seasons, so the staff in two different areas will reflect a large temperature difference between cold and hot in the environmental space at the same time. According to the new clause 5.3.2 in the Code for Design of Heating, Ventilation and Air Conditioning (200 1), it is suggested that air conditioning systems should be installed in the inner and surrounding areas with great differences in load characteristics in buildings, as well as in rooms that must be heated and cooled separately at the same time. The inner zone system mainly deals with indoor load. Compared with the load in the outer zone, the load in the inner zone is relatively stable, and the inner zone often needs cooling all year round to eliminate the indoor residual heat. The external zone system mainly deals with external heat, and the external zone load fluctuates greatly. The source of fresh air in the outer zone is generally the air conditioning system in the inner zone, which is mixed with the return air in the outer zone and reaches the air supply point after being processed by the fan coil unit. The outer area is warm in winter and cool in summer, meeting the comfort requirements.
Energy-saving technology in air conditioning system
How to make the air conditioning system adapt to the efficient and energy-saving operation under low load and how to choose energy-saving equipment in system design have become the key to air conditioning energy saving.
4. 1 Strengthen the operation management of central air conditioning and the adjustment and control of control equipment.
To improve the effective utilization rate of air conditioning energy, it is necessary to improve the professional quality of operators and avoid air conditioning energy consumption caused by poor management. Operators should keep records of equipment operation, analyze whether the readings of various pressure gauges, thermometers and flowmeters of the unit are normal and accurate, adjust the unit according to the change of air conditioning load, ensure the unit to run in an energy-saving state, conduct regular maintenance and inspection, and replace worn parts in time.
4.2 Equipment and pipeline insulation and water quality treatment
In order to reduce excessive energy consumption, it is necessary to do a good job of heat preservation of equipment and pipelines. The purpose of heat preservation is to block the internal and external temperature transfer. If the outdoor temperature is lower than the air conditioning drainage temperature, add heat preservation to prevent the air conditioning water pipe from freezing and cracking. If the ambient temperature is higher than the air conditioning drainage temperature, heat preservation shall be added to prevent the condensed water from leaking. Thermal insulation of air conditioning equipment and pipelines is also very important for saving energy consumption and reducing operating costs. Another important reason for the high energy consumption of air conditioning is the water pollution of water pipes in air conditioning system.
5, building air conditioning system equipment energy-saving operation technology
In the comprehensive energy-saving technology of building air conditioning system, the energy-saving operation technology of equipment is also very important. The main technologies include: energy storage air conditioning technology, heat recovery technology, frequency conversion technology and so on.
5. 1 energy storage air conditioning technology
The energy storage system is to store the heat taken away from the cold/hot medium by the refrigeration/heat equipment during the time when the cold/heat is unnecessary or the required cold/heat is reduced, and start this energy when the air conditioner is at the peak of cold/heat or process energy consumption. This not only reduces the loss of energy, but also effectively uses energy, which has economic and social benefits. This is a win-win energy-saving measure.
5.2 Heat recovery technology
Heat recovery technology includes waste heat recovery and condensation heat recovery of refrigeration unit. Exhaust heat recovery is an important way to make full use of exhaust energy and recover it to precool or preheat fresh air and reduce the load of fresh air. The condensing heat recovery system of refrigeration unit can not only avoid the heat pollution caused by the discharge of condensing heat into the atmosphere, but also save the boiler and its auxiliary equipment for providing hot water, and avoid the discharge of harmful substances into the atmosphere due to fuel combustion. It should be said that it is an energy-saving technology with obvious effect and environmental protection.
5.3 Frequency conversion technology
With the continuous development of power electronics technology and computer control technology, inverter has been widely used in air conditioning control system, and its application is mainly aimed at the characteristics of air conditioning control system. Different types of water chillers have relatively perfect automatic control and adjustment devices, which can automatically adjust the operation state with the change of load and maintain efficient operation, so as to achieve the method of meeting the control requirements and saving energy.
5.4 Solar air conditioning technology
Solar energy is the most important green energy, and solar thermal utilization is the main utilization form of solar energy in buildings at present. It includes passive form and active form. Passive solar houses are relatively simple in structure and low in cost, and do not need any auxiliary energy. Through reasonable arrangement of building orientation and proper treatment of building components, solar energy can be utilized by natural heat exchange. Active solar house has complex structure and high cost, and needs electricity as auxiliary energy. The heating and refrigeration system consists of a solar collector, a fan, a water pump, a radiator and a heat storage device. Solar heat-collecting wall can also be used in building envelope, using solar energy for heating.
6. Concluding remarks
The energy problem is one of the key issues in China's economic development. Energy-saving technology of building air conditioning is an effective measure to save energy, improve environment and promote sustainable economic development. The efficient and energy-saving operation of air conditioning system under high load and the selection of energy-saving equipment in system design are the key factors of building air conditioning energy saving, which is of great significance to saving energy, reducing operating costs and promoting national economic development. In future buildings, we should attach great importance to energy saving and effective use of energy in the design of air conditioning system. As long as all parties make joint efforts, the problem of energy saving and consumption reduction of air conditioning system is just around the corner.
References:
[1] Sun Ren, Nong. Analysis of energy-saving transformation of central air-conditioning system [J]. Science and technology and enterprise development. 20 12( 18)
[2] Ye Ning. Energy-saving operation of central air-conditioning system [J]. Science and Technology Information.2012 (03)
[3] Li Lingyan. Research and development of energy-saving control system for central air conditioning [D]. China University of Science and Technology 20 1 1.
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