1、外文翻译中央空调监控系统中温湿度控制的相关问题分析附录附录A外文翻译The Analysis on Related Problems of Temperaure-humidity Control for Monitoring System of Central Air-condition1 Introduction Green building focus on environmental protection, energy saving, efficient use of resources and materials, especially focus on requirements f
2、or air temperature, humidity, ventilation and cleanliness. Therefore, the use of air conditioning system is more widely. Air-conditioning control system involves many aspects, but more complex tasks to be achieved. It needs support of cold and heat. There are high-power air conditioning unit fan, bu
3、t its a great energy. Under the premise of meeting the requirements of users to air environment, only the use of advanced control strategies to control air-conditioning system, can achieve energy conservation and reduce cost of operation. The following will make a brief discussion about perspective
4、problems with the monitoring system from control strategy. 2 systems basic structure and working principle Structure and composition of air-conditioning system generally include the sections: (1) Part of the new wind Air-conditioning system during operation to capture part of the outdoor fresh air (
5、ie fresh air), this part of the fresh air to meet indoor staff required minimum fresh air volume, so air conditioning system of fresh air taken into the amount determined by air-conditioning system service uses and hygiene requirements. The new wind into the general population in the surrounding are
6、as from pollution. These new wind into port and air conditioning systems and new air ducts installation of new wind Dust (new style air filter), new air heaters (also known as air-conditioning system in a heater) came together to form a new air system air conditioning system. (2) Part of air purific
7、ation Air-conditioning system according to their different uses, purification of air in different ways. Therefore, in the air purification system has set an initial effect of a simple air filter cleaning system, but also set an initial effective air filter and air filter efficiency level of the gene
8、ral purification system, in addition to setting an initial efficiency air filters, one in the efficiency of air filters and a HEPA filter for three high-purification system filter. (3) Part of the air heat, wet Air heating, humidification and cooling, dehumidification, will combine the process, know
9、n as the air conditioning system, heat, wet part. In the air to heat, wet processing, surface-air heat exchanger. Setting a new air intakes in the system, a return air as the air before the air heater in a heater; set before cooling dehumidification air heater, known as the secondary air heater; set
10、 in air-conditioned room before sending outlet air heater, known as the three air heaters. Three air-conditioned room heater to regulate the main role of the temperature, the thermal coal used for the hot water or electric heating. The surface heat exchanger in cold water or a refrigerant through th
11、e low-temperature water-cooled surface, called the direct evaporative cooler or cooler surface, but also by spraying cold water or hot water washer, There are also direct water spray of steam approach to achieve the air hot and wet processing. (4) The section of air transportation and distribution a
12、nd control Fans and air conditioning systems to send, return air pipe as part of air transport. Duct in the regulation of air valve, butterfly valve, damper, boot valve and air outlet such as points, control section. Air-conditioning system according to the different air resistance, set the number o
13、f fans are different, if the air conditioning system for a wind turbine set, the fans not only from the air role, the role was underway as a single return air fan system; if the air conditioning system set two fans, one for the blower, another fan for the back, then called the two-fan system. (5). c
14、old and heat source of air conditioning system, Air conditioning systems used in the cold cold source is generally divided into natural and artificial sources of cold source. Natural cooling source generally refers to ground water from deep wells, artificial cold source generally refers to the use o
15、f artificial refrigeration means available, which includes the vapor compression refrigeration, absorption refrigeration, and steam jet refrigeration, and other means. Modern large-scale buildings are often used for central air conditioning system Its working principle is when the ambient temperatur
16、e is too high, the air conditioning system, through re-circulated to the indoor heat away so that the indoor temperature is maintained at a certain value. When the circulation of air through the fan coil, the high-temperature air through the cooling coil of aluminum metal prior to heat exchange coil
17、 of aluminum absorbs heat from the air, the air temperature decreases, and then the cycle of freezing air given away after Indoor. Chilled water cooling coil provided by the cooling machine, cooler by the compressor, condenser and evaporator component. Compressor to compress refrigerant, refrigerant
18、 compressed into the condenser, cooled by cooling water into the liquid, precipitation heat from the cooling water, and drained the cooling tower air. Liquid refrigerant from the condenser into the evaporator, evaporation, so that chilled water cooling, and then into the water-cooled chilled water f
19、an coil heat absorption in the air, again and again, cycle continuously, the indoor heat away. When the ambient temperature is too low, the need for hot water into the fan coil, and the above-mentioned principles, as given away heated indoor air. After air cooling, water analysis of the air relative
20、 humidity decreased, become dry, so need to increase humidity, it is necessary to install humidifiers, water spray or spray to steam air humidification treatment, the use of such wet air to supplement inadequate amount of indoor water vapor. 3. central air conditioning system control problems 3.1 Th
21、e characteristics of the controlled object Air-conditioning system control objects are mostly thermal objects, from the perspective of control, has the following characteristics: (1)more disruptive For example, incoming solar radiation through windows, heat is a function of time, subject to weather
22、conditions; outdoor air temperature, room temperature through the envelope on impact; through doors, windows, building cracks penetrated the outdoor air temperature impact; to change gas (or maintain a certain positive pressure room) adopted a new style, its temperature changes have a direct impact
23、on the room temperature. In addition, the electric heater (air heater) power supply voltage fluctuations and hot water heater hot water pressure, temperature, steam pressure fluctuations, will affect the room temperature. So much interference, so that air conditioning load in the larger context of c
24、hange, and their location into the system, form, size and frequency of such magnitude, both with the construction of the structure (building thermal performance), use of different and different, even with air conditioning technology itself. Should be considered in the design of air conditioning syst
25、ems to minimize interference with or taking anti-jamming measures. Therefore, we can say that air conditioning project is based on building thermal, air-conditioning technology and automation technology based on a comprehensive engineering. (2) Multi-condition Air conditioning technology in the trea
26、tment process is highly seasonal. Year, at least into the winter season and summer transition. In recent years, distributed systems in the air conditioning system, air conditioning for multiple applications to create conditions favorable conditions. As the air conditioning system, diversification, o
27、perational management and control devices to become complicated. Therefore require operators to be in strict accordance with the energy-efficient design requirements, including technical measures to operate, and maintain, not free to change run Cheng Xu, and Zhongs Shebei Chaigai system. (3) tempera
28、ture, humidity correlation Describe the state of the two main parameters of air temperature and humidity as they are not completely independent of the two variables.When the relative humidity changes will cause humidification (or dehumidification) action, the results will lead to temperature fluctua
29、tions; and temperature changes, so indoor air vapor saturation pressure, the absolute moisture content in the same situation, directly change the relative humidity (relative humidity to reduce the temperature increased, the temperature increase reduces relative humidity). Associated with the paramet
30、ers such as relative parameters. Clearly, in the temperature and humidity of the air-conditioning systems required to form the automatic control system should pay attention to this feature. 3.2 Control ProblemsSuch as central air conditioning system for large, complex process (or object) of the cont
31、rol implementation, usually by some kind of guidelines, the lower its decomposition into a number of subsystems to exercise control, co-ordination in the top performance among the various subsystems, making integration After the system is in some sense the optimal state. Problems in control mainly i
32、n: (1) uncertainty Traditional (2) highly nonlinear (3) semi-structured and unstructured (4) system complexity (5)Reliability 4. the selection of control strategy The uncertainty of complex systems, since the controlled object (process) is difficult to use the characteristics of the mathematical mod
33、el accurately described. The traditional PID control theory based on classical control and state space representation based on modern control theory methods to achieve high dynamic and static charged object quality control is very difficult, usually with black-box method, that method of input and output description control sy
