Weak current College】 【Central air conditioning system and energy-saving analysis and summary --- Power By】 【China power house network.

<br> 1. air conditioning design key to control <br> <br> 1.1 cooling load and thermal load design control <br> <br> In the central air conditioning system construction drawing design stage, thermal load and itemized hourly of cooling load .calculation. Load calculation should be dynamically calculated, depending on the actual load situation select suitable heat source. Due to the system and heat source and equipment in the performance of some load on the system has an important impact, therefore, equipment selection, on the .one hand, taking into account the particular design conditions, at the same time should also be stressed that the system operation and part load performance of the system. <br> <br> Design of the air-conditioning system of cooling load and thermal design ., equipment selection did not fully take into account the characteristics of the load of air conditioning systems and equipment performance, the air conditioning unit capacity, pipe diameter, pump configuration, end equipment design and the high side, resulting in increased investment and running costs. .While many buildings air conditioning system is not up to full-load operation, even in the hottest month is still idle air conditioning unit. Pump selection is too large or pump matching motor power is too large, inefficient, wasting energy. Multiple parallel operation of .frozen water pump, there is no basis for the cooling load of change adjustment opening number, but no matter the size, cold load is the maximum cooling load moving chilled water pumps, wasted energy. <br> <br> 1.2 air-conditioning system .design control <br> <br> Water system mostly constant flow, design flow by maximum cooling load and 5 ° c temperature difference of backwater. The actual prevalence of large flow small temperature difference, maximum load a little time, most of the time when .running under partial load, the actual temperature is less than the actual temperature, design flow ratio design flow 1.5 times more significantly exceed the design flow, the water pump power consumption significantly increase [2]. <br> <br> Designers should pay attention .to the water system design, each water loop for hydraulic balance calculation, pressure differential vastly circuit to take effective measures to ensure that the loop hydraulic balance, avoid hydraulic and thermal imbalance, carefully proofread and calculation of air conditioning water system-related parameters, the .practical implementation of energy-saving design standard values, use electric 2-way valve for water flow through the air conditioning Terminal to control, to flow with the load, actively promote variable speed pump, winter and summer dual-speed pumps and other energy- .saving measures. Recent research shows that increasing the temperature difference that backwater to reduce the energy consumption of the transport system is greater than the resulting devices heat reduction increased energy consumption, therefore the entire air-conditioning system, has a certain energy efficiency, not only .to eliminate large volume, small temperature difference phenomena, but also gradually introducing a small flow, design of large temperature difference. As a result of increased temperature difference for backwater, device running parameter changes, the design of the programme through technical and economical comparison. .At the same time should also be concerned about the cooling water temperature on the impact of energy consumption of air conditioning systems. <br> <br> (1) reduce the cooling water temperature <br> <br> Due to the cooling water temperature .more low, cooler, the higher the refrigerating factor. Cooling water supply temperature increase of 1 degree Celsius, Austin cooler dropped COP nearly 4% [3]. Reduce the cooling water temperature on the need to strengthen the operational management of cooling towers. First ., stop the running of the cooling tower, the inlet and outlet valves should be closed. Otherwise, because from the closure of cooling tower water temperature is higher, the mixture of cooling water temperature will improve, cooler cooling factor is reduced. Secondly, the .cooling tower with a period of time, should promptly repair, otherwise the efficiency of the cooling tower will decrease, not adequately for cooling water cooling. <br> <br> (2) improve the freezing water temperature <br> <br> The .freezing water temperature is higher, cooler cooling efficiency. Chilled water supply temperature increase of 1 degree Celsius, cooler cooling factor may increase 3%, so in daily operation should not blindly to lower the freezing water temperature. First of all, do not set too .low, and cooler chilled water temperature setting. Second, be sure to close down cooler water valve to prevent some chilled water piping, otherwise walk by-pass, after running cooler water is reduced, resulting in chilled water temperature was cold air to too low .a level. <br> <br> 1.3 fresh air system design on energy saving <br> <br> Rational use of fresh air system, or you can effectively control energy usage. In meeting the health conditions, reduce the new amount of wind .or according to the actual need to be adjusted for VAV system. Have the exhaust system, use of indoor energy on fresh air for preheating and cooling (heat recovery technology), can effectively reduce the energy consumption of air conditioning systems. <br> < .br> 2. air conditioning use in energy-saving measures <br> <br> Building energy-saving air conditioning 2.1 <br> <br> (1) reasonable structure design envelope. The amount of cooling and heating in buildings through walls, .doors and Windows of the room and so pass source, thus building envelope insulation in the building of energy-saving plays an important role. In particular, the construction of the window, should be able to play the role of controlling the solar exposure and to .limit the size of the window wall; for a window size larger buildings should consider using heat absorbing glass, heat reflective glass or shading measures such as the sun visor, roof, roof eaves, curtains, etc. block heat absorption. In the outdoor temperature .is low you can directly use natural air as an energy source, so the window structure should be able to open or set to open nature vents [4]. <br> <br> (2) improve the airtight doors and Windows. Especially in .summer, less room for air times. For example, the design may be airtight good doors and Windows. Installing doors and Windows closed is to improve airtightness of important means. <br> <br> (3) in the case of cooling load in .larger buildings. The surface color to light as well. Building exterior envelope design-time to put the heat capacity of the material on the external sheath of indoor side. the heat capacity of the insulation on the outer side to reduce the thermal load of the .building envelope. <br> <br> (4) select better indoor air parameters. If air-conditioning outdoor design parameters for the set value, the summer air conditioning roomCalculation of indoor air temperature and humidity lower room cooling load calculation, energy system. .In meet the comfort requirements, to maximize the summer interior design temperature and relative humidity, minimize winter indoor temperature and relative humidity, don't blindly forced for indoor air temperature is too low, too dry, the winter indoor temperature is too high. < .br> <br> 2.2 rational utilization of environmental factors <br> <br> The outdoor temperature is low (especially at night), note the room ventilation, the day that use shading measures, air conditioner run to close the doors and Windows are .effective measures to save energy. <br> <br> 2.3 establishment of intelligent systems and control technology <br> <br> Application of intelligent integrated systems control technology on central air conditioning system and energy-saving control at all times, is now a .more effective means of electronic control. In particular the integrated intelligent control system modules, reduced application threshold, general building energy consumption should be based on the actual situation of the different smart integrated system control solutions to achieve energy-saving purposes. It can be based .on the actual operation of air-conditioning, automatic operation of the air conditioning parameters optimal for Adaptive adjustment, the aim of reducing energy consumption [5]. <br> <br> At the same time, with the development of intelligent building, establishing .companion air conditioning intelligent automation system is also indispensable, it run on air conditioning system plays a key role. Air-conditioning automatic control system although the increased investment, but can maintain good indoor environment on the basis of save operating costs. A properly designed and .run well-managed automation system can significantly save operating costs, so that the owners in a relatively short period of time to recover their investments could also improve automation service quality, reduce the impact of the external environment. <br> <br> 3. .strengthen the management of the central air-conditioning <br> <br> Day-to-day management is the central air conditioning energy efficiency is the key to effective and efficient. A design and good air conditioning system, if improperly managed, can not .reach the purpose of energy saving. The air conditioning energy saving purposes, the day-to-day management of energy-saving measures including: <br> <br> (1) strengthening air-conditioning operations personnel training, to improve management quality. .Understand the changes under outdoor parameters for reasonable and effective regulation. Active promotion of water-loop heat pumps, heat recovery, VAV, vwv and other energy-saving technology. <br> <br> (2) strengthen routine and regular on the device .and system maintenance and cleaning. For example, maintenance of air conditioning components, condenser heat exchanger heat transfer surface in regular descaling or ash, filters, limber, periodic cleaning. <br> <br> (3) often check the automatic control equipment and .instruments, to ensure that its work properly. On the system's operating parameters to monitor never normal operating parameters in the system, for reasonable modification. Recurring problems with the device selection is too large, high energy consumption. Possible to shorten the pre-cooling of .time. <br> <br> (4) when the transitional season room cooling load, you should try to use outdoor fresh natural cooling capacity, save the artificial cold cold source. <br> <br> Central air conditioning energy saving and involve .a wide range of wider, the design from the air conditioner, air conditioning installation and operation management, etc. are worthwhile improvements. In any case to improve energy efficiency, efficient use of energy from increasing to take measures to resolve the problem, this is .the science of air conditioning energy saving way..