Home News Content

Energy-saving Technology Of Central Air-conditioning System

Jul 14, 2020

Energy-saving technology of central air-conditioning system


Under the new economic situation in which the growth of corporate profits generally slows down, reducing the operation and maintenance costs of the central air-conditioning system is also one of the beneficial measures to enhance the competitiveness of the enterprise. What are the energy-saving transformation measures for the central air-conditioning system? Here, as a company focused on the central An energy-saving service company for energy-saving solutions for air-conditioning systems, Xinriyuan is answering everyone.


1. Energy saving of split air conditioner


Split air conditioners in hotels and office buildings often wear shirts in winter and quilts in summer, resulting in waste of hot and cold energy! The control limits 26℃±1℃ in summer and 20±1℃ in winter, which can save 5-10% energy. For example, the original set temperature is 22±1℃ in summer, and energy can be saved by 3% per liter of 1℃, which is the opposite in winter.


Air-conditioning energy-saving technology


In recent years, there is a hydrocarbon (CH) refrigerant for replacing R22 refrigerant. The energy saving rate after replacement is 15-25%. The energy saving rate is related to the energy efficiency level and service life of the original machine. The replacement of hydrocarbon refrigerants saves energy immediately, and is currently used for small split machines with 1~10HP. The material and technology have been proven to be mature after several years of use.


2. Air source heat pump, water source heat pump, ground source heat pump


1. The air source heat pump is used to produce hot water, and the energy efficiency ratio COP=3.5, that is, the power consumption of 1kW can produce 3.5kW of heat, and the efficiency is higher.


2. Water source heat pump machine (professionally called water ring heat pump machine), that is, a group of cooling towers for cooling, and each terminal unit can be independently cooled and heated. Water cooling is more energy-efficient than air cooling COP>4.5. With the same input power, the cooling capacity of water-cooled machine is 30~40% larger than that of air-cooled machine. Each user can decide on and off time and temperature setting according to their own situation, which can get better energy saving benefits


3. Ground source heat pump air conditioner: using the characteristic of constant temperature of groundwater about 18~20℃, taking underground heat as cooling or evaporation heat source, because the groundwater temperature is 10~12℃ lower than the return water temperature of the cooling tower, reducing the cooling water temperature by 10~12℃ , Air-conditioning host can save energy by 30~36%.


Frequency conversion air conditioner of energy saving technology of central air conditioning system


3. Ice storage air conditioner


The principle of the ice storage air conditioner is to use the valley electricity to cool the ice at night, the ice is melted during the peak electricity during the day to provide cooling, and the valley electricity is used to make ice at night, and the ice is melted to provide cooling when the peak electricity is high during the day. However, the one-time investment in the machine room increases by about 30%. The ice storage tank and tank must have a large placement area and space. The loss of multiple heat exchanges, the flow and head of several stages of refrigeration, cooling, heat exchange pressure pumps are all It should be calculated accurately to get the best energy efficiency.


4. Frequency conversion of water pump and fan


The air conditioning refrigeration and cooling pump flow design will have a 10-20% margin, the load will change during air conditioning operation, the host will load and reduce the load, and the cooling and cooling water flow can also be increased or decreased accordingly. The temperature sensor, differential pressure sensor, PLC and frequency converter are used to control the speed of the freezing and cooling pumps to reach a temperature difference = 5°C. The freezing and cooling pumps can save energy by 30-50%. The fan channel is the same as above.


5. Cooling tower fan temperature control and energy saving


When the cooling tower return water temperature drops from 32°C to 1°C, the air conditioner can save about 3% of electricity. When the cooling tower return water temperature drops to 26°C, the water temperature drops again, and the power saving of the host is not obvious. Turn off the fan motor at this time , The power saving per hour is the motor power.


Ground source heat pump for energy saving technology of central air conditioning system


Several suggestions for the design and selection of air-conditioning system and air-conditioning host:


1. The energy efficiency ratio of centrifuges and screw units for large air-conditioning systems is higher.


2. Water-cooled chillers are more energy-efficient than air-cooled chillers. Air-cooled machine COP=3~3.5, while water-cooled machine COP≥5~6.


3. Some large imported brands use a number of energy-saving innovative technologies. The new model of full-fluid screw machine COP≥5, centrifuge COP≥6. Choosing the right brand model means that the project has already saved 10% energy.


Central air-conditioning system energy-saving water pump fan frequency conversion


4. The magnetic suspension refrigerator has entered the air-conditioning system, its friction resistance is greatly reduced, no refrigeration oil lubrication, and the thermal resistance caused by oil scale does not exist, the rotation speed reaches tens of thousands of revolutions per minute, so the energy adjustment range is larger and the energy efficiency ratio is higher At present, the cost of this main engine is much higher than that of oil-lubricated units.


With the tightening of environmental protection policies and the frequent occurrence of problems with older generation air-conditioning systems, as well as the need for enterprises to reduce operation and maintenance costs, energy saving of central air-conditioning systems will also be adopted by more enterprises.