Central air conditioning to achieve energy saving 11 measures

The main components of the equipment are air conditioning host (hot and cold source) wind cabinet fan coiler, etc.; central air conditioning is an indispensable energy consumption in modern buildings operating system, central air conditioning system to provide people with a comfortable living and working environment at the same time, but also consume a large amount of energy.

At present, most of the air-conditioning chilled water systems use 1-stage pump fixed flow system. Water pump capacity is selected according to the maximum load of the chiller, and throughout the year in a fixed water flow rate.

When some air-conditioning terminal shutdown, the water valve can not be closed, the return water temperature is reduced, making the temperature difference between the supply and return water is reduced. Due to seasonal day and night and the use of buildings with different functions, the actual air-conditioning load in most of the time of the year is much lower than the design load ( also talked about ), 60% of the time throughout the year the actual load is in the design of the load of 50% ~ 70% of the following operation, and cold water flow rate is unchanged, the supply and return between the temperature difference between the design of 5 ~ 7 ℃ down to 0.5 ~ 1.0 ℃, that is, the system in the flow of large temperature difference between the work. Work in the case, thus wasting the pump operation of the delivery energy, and increase the piping system heat and cold loss, from the central air conditioning system air treatment process can be seen, the lower the indoor temperature in summer, the lower the relative humidity, the greater the energy consumption of the system equipment; the higher the indoor temperature in winter, the higher the relative humidity, the greater the energy consumption of the system equipment, and accordingly, the initial investment and operating costs have also increased, due to the comfort of every person on the As each person's requirements for comfort standards vary greatly, so the civil central air conditioning can have a wider range of comfort zone.

(1) refrigeration, cooling pump matching energy-saving
For example: Shenzhen and surrounding areas in operation in the cooling, refrigeration pumps, there are 20-30% is not matched, mainly manifested in high head. Example XX pharmaceutical factory host 853RT, freezing pump flow Q = 600m ³ / h, head 42m, N = 110kW; cooling pump Q = 660m ³ / h, H = 31m, N = 75kW. After surveying and calculating the flow rate can be unchanged, the freezing pump head changed to 32m, the cooling pump head was changed to 20m. freezing pump from 110kW to 75kW, cooling pump from 75kW to 55kW. after transformation, the noise is reduced. After remodeling, the noise is reduced, the wear and tear is reduced, the energy saving is 35%, and the air conditioning system is safer and more efficient. Transformation costs are very small, change a few pumps about 10 million dollars, annual power savings of 70 ~ 800,000 degrees. The flow and head are matched, which is both energy-saving and safe.

(2) Air-conditioning system and air-conditioning unit design selection
1, large air conditioning system with centrifugal machines, screw units with higher energy efficiency. Full-liquid screw machine COP>5, while the centrifugal machine COP>6.
2, water-cooled chiller than air-cooled machine energy efficiency ratio. Air-cooled machine COP = 3 ~ 3.5, while the water-cooled machine COP ≥ 5 ~ 6.
3, some imported brands, the use of a number of energy-saving innovative technologies, new models of full-liquid screw machine COP ≥ 5, centrifugal machine COP ≥ 6, choose the right model of such a brand, it means that the project has been energy-saving 10%, or even higher.
4, magnetic levitation refrigeration machine has entered the air conditioning system, its frictional resistance is smaller, without freezer oil lubrication, oil scale caused by the thermal resistance does not exist, the speed of tens of thousands of revolutions / minute, so the energy regulation range is larger, energy efficiency ratio is higher. Currently the host than the oil lubrication unit will be twice as expensive.

Within this comfort zone, when cooling in summer, take a higher value of temperature and humidity; when heating in winter, take a lower value of temperature and humidity, which can obtain a certain energy-saving effect. Changes in temperature and humidity within the building and building energy saving has a close correlation, according to empirical statistics show that if the set value temperature in summer will be adjusted downward by 1 ℃, will increase the energy consumption by 9%; if the set value temperature in winter will be adjusted upward by 1 ℃, will increase the energy consumption by 12%, therefore, the temperature and humidity within the building to control within the set value accuracy is an effective measure of energy saving of the building's central air conditioning, in order to reduce the energy consumption of air-conditioned rooms Indoor temperature and humidity base, in order to meet the production needs and human health, summer as much as possible to improve, winter should be reduced as much as possible.

Now some owners blindly pursue the “cold enough” realm, a substantial increase in indoor temperature and humidity design standards, to do so, not only unnecessary waste of large amounts of energy, but also produces a sense of comfort, the higher the precision of the air-conditioning system temperature and humidity control, the better the comfort, while the energy saving effect is also more pronounced. The accuracy of the signal measured at the front end of the air conditioning system directly affects the degree of precise control of the central air conditioning system.

Therefore, the measured signals, especially the temperature and humidity of such analog signals, must be as accurate as possible, and must choose a high control accuracy of the BAS for central air conditioning control. Because, BAS using DDC (Direct Digital Controller) to directly control the opening of the motorized water valve valves, without the need for intermediate regulators; In addition, DDC contains a wealth of computational control software, such as Proportional Integral Derivative (PID) algorithm, fuzzy control algorithms, genetic algorithms, etc., to ensure the accuracy of the control.

In recent years, the new design of central air-conditioning has been stipulated to use automatic condenser cleaning technology, the old air-conditioning energy-saving transformation is also more and more with automatic condenser cleaning system. The basic principle of automatic condenser cleaning is to send the sponge ball into the condenser through a device at regular intervals to scrub the scale, sludge, fungus and algae on the inner wall of the copper tube, so that the condenser reduces the thermal resistance and maintains the best thermal state, and saves energy by 10~30%. It is a good method and new technology to reduce chemical emission, reduce manual labor, improve labor protection conditions, energy saving and emission reduction.