【 Weak current College 】 air-conditioning system optimization become the key to building energy efficiency---Power By 【 China power house network 】

With energy-saving technology has been improved, the air conditioning energy saving target from the past to sacrifice comfort standards or reduce air quality requirements for energy-saving, to guarantee the comfort requirements to improve energy efficiency to save energy. Our energy efficiency low, HVAC energy consumption characteristics, such as efficient use of energy-energy saving target of ideas is our air conditioning energy saving a large market opportunity.
　　
Total energy consumption in buildings in occupies a social end energy consumption 20.7%, building energy consumption on the national and community energy burden, has to a certain extent restricted the sustainable development of our economy. According to the energy sector of research and practice, it is generally believed that building energy-saving potential in all of the largest, most direct and effective manner.
　　
Widely used in modern building an air conditioner, give (PAI) water, lighting, elevators, and other energy-consuming equipment. Air conditioning has been building energy consumption in households, or about the whole building energy consumption of more than 35%. The energy consumption of air conditioning systems have two aspects: one is for supply air handling equipment, cold and heat energy consumption of heat and cold sources, such as compression refrigerating power, absorption refrigerating steam or gas consumption, the consumption of coal, fuel oil boiler, gas or electricity; on the other hand is designed to give the room air and conveying air conditioning circulation water, fan and pump consumes. Therefore, building energy-saving air-conditioning system mainly includes reducing device power consumption and operating control energy consumption in two major respects.
　　
Reduce energy consumption and heat source as critical
　　
The energy consumption of heat and cold sources by building the required cooling and heating capacity, building of chilling and air conditioning energy consumption of the cooling load and thermal load, including outdoor meteorological parameters (such as the outdoor air temperature, air humidity, solar radiation intensity, etc.), indoor air-conditioning design standards, exterior heat transfer characteristics of Windows and doors, Interior, lighting, equipment of thermal, powder and wet conditions and the impact of the new amount of wind, etc. Reduce heat and cold sources of energy consumption through the following three forms:
　　
First, reduce the cooling load and thermal load. Cooling load and thermal load is the most basic of air conditioning system, refrigerator, heating boilers, hot and cold water circulation pump, as well as to the room air, hot air conditioning, fan-coil and other product specifications model choice is to cooling load and thermal load. If you can reduce the construction of the cooling load and thermal load, not only can reduce refrigerator, heating boilers, hot and cold water circulation pump, air conditioner, fan-coil and other product specifications, reducing air conditioning system of initial investment, and these devices specification decrement, the desired distribution power will also decrease, in favor of reducing the initial investment and distribution equipment and air conditioning equipment daily run electricity consumption, lower operating costs. Reduce the cooling load and thermal load is the most fundamental of commercial building energy-saving measures. Room hot and cold quantity losses through the room's walls, doors and Windows, and so pass out, reduce the cooling load and thermal load of the building is to improve the building's insulation performance.
　　
Second, reasonable design reduces system load. At present, China's most designers in the design of the air-conditioning system is often used to estimate the load index, and for security considerations often value too large, resulting in a system of heat and cold sources, energy transmission and distribution, device at the end of the heat exchanger capacity is significantly more than the actual demand, forming large horse car, both add investment nor energy. As shown in table 1, reasonable lower system load, you can effectively reduce system power consumption.
　　
Third, the control of ventilation rate and reduce indoor humidity design standards. In some buildings air conditioning system, requires significant introduction of fresh air to meet the requirements of the indoor air quality. In accordance with its fresh air into the way, you can also direct the transitional seasons and winter into the outdoor temperature and humidity relatively low outdoor air to take the room by the heat and moisture load without the use of centralized cooling systems achieve "free" cooling energy saving effect. In summer, take advantage of the outdoor air temperature at night relative, you can non-trading hours prior the cooling air. Take away part of indoor heat, reduce daytime work hours of cooling load for intermittent free cooling.
　　
From the air-conditioning system air treatment process can be seen, the indoor temperature and relative humidity in the summer, winter indoor temperature and relative humidity is low, the greater the energy system. In order to save energy, the air conditioning room indoor temperature and humidity of the base to meet the production requirements and human comfort conditions, reduce indoor humidity design standards, such as: temperature is 17 ° c to 28 ° c, relative humidity of 40% to 70% range, summer winter with high values, low values. Control and correct use of the new amount of wind is the air conditioning system effective energy-saving measures, in meeting the health care, compensation exhaust, the dilution of hazardous gases concentration, maintain positive pressure requirements, do not blindly increasing outdoor air, CO2 concentration can be used to control fresh air intake air volume controller.
　　
Air conditioning system and energy-saving attention to two major aspects
　　
In addition to efforts to reduce building energy consumption of heat and cold sources, HVAC in building energy saving is the most important optimization of air conditioning system, you can take variable flow technology and increase the supply air temperature differential and difference of backwater to improve system efficiency.
　　
First, using the variable flow technology. Vav (VAV) system can change the air ways to control different room temperature and humidity. At the same time, when the room design of the load is less than the load, VAV system can adjust air volume of transport, thereby reducing the total transport air flow system. In this way, the air conditioning equipment capacity can decrease, can save device costs of investment, but also further reduce energy consumption of the system. The air volume decrease and savings in tackling air required energy. Information display, using VAV system can save energy up to 30%, and at the same time improve environmental comfort. The system most suitable for floor space and room number of buildings, especially the Office building, the better its simple operation, comfort, energy-saving effect. According to statistics, using the variable air volume (VAV) air conditioning system, air transport energy consumption savings of 1/3, reduce equipment capacity 20%-30%.
　　
Second, increased air temperature difference and for the backWater temperature difference. If the system of transport volume of cold (hot) containing cold (hot) media for water temperature difference with a larger value, the temperature difference when it vs. the original is N, the shows from the flow calculations, using the flow when large temperature difference to the original flow of 1/N, and pipeline losses i.e. pump or fan of the power consumption is reduced to 1/N2, significant energy saving effects. It should meet the air quality, human comfort and technology requirements, increased temperature difference as far as possible, but not suitable for return water temperature is generally greater than 8 degrees centigrade.
　　
Automatic control and wide frequency technology became
　　
Air conditioning system operation and management of automatic control, not only can guarantee an air conditioned room humidity accuracy requirements and conserving human, and prevent system superfluous energy loss and conserve energy with important links. Air-conditioning automatic control system including control and heat source of energy, enthalpy value controls, new air control, devices and stopping time and operating mode of the control, set the temperature and humidity control, auto shows, records, and other content available through the prediction of indoor and outdoor air parameters (temperature, humidity, enthalpy etc) to maintain indoor amenities for the constraint, the minimum energy consumption, as the evaluation function to judge and determine the desired amount of heat and cold, hot and cold source and air conditioners, fans, pumps run number and work order, running time and air conditioning system part of the operation, to achieve the best savings run results.
　　
The control system for air conditioning, with power electronics technology and microcomputer control technology, the growing use of frequency converters, air-conditioning control system adopts frequency conversion technology is no exception. Different types of unit are more perfect automatic control regulation device, can automatically adjust with the load changes, and maintain the health of efficient operation. Air conditioning unit, terminal equipment and the pump, adopt the frequency conversion control, you can make the device more than 30% less energy.