Annual running average energy efficiency ratio
DATE:2025-01-07
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The EER of a high-efficiency refrigeration station is the EER of the refrigeration system, the value of which is the ratio of the cooling output of the refrigeration system to the amount of electricity required. High-efficiency refrigeration station includes three main components: 1) high-efficiency equipment. Including chiller units, pumps, cooling towers and other air conditioning plant room major energy-consuming equipment. 2) Energy-efficient water system. The main goal is to reduce system resistance, reduce the energy consumption of the transmission and distribution system. 3) Intelligent control system and energy consumption, energy efficiency evaluation system. For high-efficiency refrigeration stations, there must be a perfect and accurate monitoring and system energy consumption and energy efficiency evaluation system, so as to have a clear understanding of the energy efficiency of each piece of equipment and system, to compare and analyze the difference between the design efficiency and the actual operating efficiency, and to continuously optimize the operation strategy to ensure that the air conditioning system continues to be highly efficient.
The design of high-efficiency refrigeration station needs to meet the process of production with cold and building end with cold demand as the premise, configure the corresponding equipment and perfect intelligent control system. The following from the chiller, cooling tower, pumps and control systems in several aspects of the design of high-efficiency refrigeration station briefly.
Chiller chiller is the core equipment of the refrigeration station, according to the project cold load selection of chiller is a high-efficiency refrigeration station needs to be the first issue to consider. Before selecting the chiller, it is necessary to analyze its operating conditions, generally through the analysis of the project cold load and combined with the unit configuration and meteorological data, to determine the most common operating conditions of the chiller, and select the most common operating conditions under the higher efficiency of the unit. For the same cooling capacity demand, there are usually 2 modes of chiller unit configuration: the first one is the matching of units with the same cooling capacity (i.e., what is usually called equal-sized units); the second one is the matching of units with different cooling capacity (i.e., what is usually called big and small units). In the use of fixed-frequency chiller units, the matching mode of large and small units increases the adjustability of the cooling source compared to the matching mode of equal large units, which has certain energy-saving effect. However, in terms of group control strategy, the main problem to be solved by matching equal large units is to determine the number of chiller units to be put into operation, while the main problem to be solved by matching large and small units is not only to determine the number of chiller units to be put into operation but also to solve the combination problem of the chiller units to be put into operation, but also to solve the problem of the combination of the chiller units to be put into operation. The main problem to be solved is not only to determine the number of chiller units put into operation, but also to solve the problem of the combination of chiller units put into operation, which is far more complicated than the former. Therefore, in the design of high-efficiency refrigeration station, usually used in large units such as matching mode.
Cooling tower in the high-efficiency refrigeration station, cooling tower configuration form should be consistent with the chiller. Under the premise of not lower than the minimum water inlet temperature of the chiller, reduce the cooling tower water temperature as much as possible, so that it is as close as possible to the outdoor wet bulb temperature. For specific projects, in the case of a given chiller group inlet and outlet water temperature, according to GB/T 50392-2016 “Mechanical Ventilation Cooling Tower Process Design Specification”, the design wet bulb temperature of the cooling tower is appropriate to use the local multi-year average, the average daily wet bulb temperature of the hottest days in the hottest period of the year in the 3-month period of not more than 5 ~ 10 d. Open cooling tower power consumption ratio is less than the closed cooling tower, but because of its circulating medium will be concentrated due to evaporation, must be dosed, replenishment, and easy to be contaminated, so for the emphasis on stability and continuous operation of process air-conditioning high-efficiency refrigeration station, more suitable for the use of closed cooling towers, especially in the northern region. 2.3 water pumps in the high-efficiency refrigeration station, the pumps of the energy consumption is second only to the water cooler, so a reasonable selection of water pumps For the energy saving of the cooling system is crucial. Should be based on system characteristics and pump characteristics curve for pump selection, while paying attention to ensure that the maximum efficiency of the pump in its longest running time within the range of conditions (load rate of 30% ~ 100%), rather than simply make the highest efficiency point in its design conditions. In the air-conditioning chilled water primary pump variable flow system control process, more use of differential pressure control system operation regulation, according to the system characteristics of a reasonable arrangement of differential pressure sensors can achieve different energy-saving effect, in the end of the system when the trend of load changes in the same way, differential pressure sensors are arranged at the end of the system control of energy saving effect is most obvious.
It can find the dynamic optimal power relationship between chiller units, pumps and cooling towers under different load demands, so that the overall energy consumption of the refrigeration station can be greatly reduced without decreasing the cooling capacity, successfully solving the problem of operating efficiency of the full frequency conversion refrigeration station and enabling the safe and stable operation of the refrigeration station.
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The design of high-efficiency refrigeration station needs to meet the process of production with cold and building end with cold demand as the premise, configure the corresponding equipment and perfect intelligent control system. The following from the chiller, cooling tower, pumps and control systems in several aspects of the design of high-efficiency refrigeration station briefly.
Chiller chiller is the core equipment of the refrigeration station, according to the project cold load selection of chiller is a high-efficiency refrigeration station needs to be the first issue to consider. Before selecting the chiller, it is necessary to analyze its operating conditions, generally through the analysis of the project cold load and combined with the unit configuration and meteorological data, to determine the most common operating conditions of the chiller, and select the most common operating conditions under the higher efficiency of the unit. For the same cooling capacity demand, there are usually 2 modes of chiller unit configuration: the first one is the matching of units with the same cooling capacity (i.e., what is usually called equal-sized units); the second one is the matching of units with different cooling capacity (i.e., what is usually called big and small units). In the use of fixed-frequency chiller units, the matching mode of large and small units increases the adjustability of the cooling source compared to the matching mode of equal large units, which has certain energy-saving effect. However, in terms of group control strategy, the main problem to be solved by matching equal large units is to determine the number of chiller units to be put into operation, while the main problem to be solved by matching large and small units is not only to determine the number of chiller units to be put into operation but also to solve the combination problem of the chiller units to be put into operation, but also to solve the problem of the combination of the chiller units to be put into operation. The main problem to be solved is not only to determine the number of chiller units put into operation, but also to solve the problem of the combination of chiller units put into operation, which is far more complicated than the former. Therefore, in the design of high-efficiency refrigeration station, usually used in large units such as matching mode.
Cooling tower in the high-efficiency refrigeration station, cooling tower configuration form should be consistent with the chiller. Under the premise of not lower than the minimum water inlet temperature of the chiller, reduce the cooling tower water temperature as much as possible, so that it is as close as possible to the outdoor wet bulb temperature. For specific projects, in the case of a given chiller group inlet and outlet water temperature, according to GB/T 50392-2016 “Mechanical Ventilation Cooling Tower Process Design Specification”, the design wet bulb temperature of the cooling tower is appropriate to use the local multi-year average, the average daily wet bulb temperature of the hottest days in the hottest period of the year in the 3-month period of not more than 5 ~ 10 d. Open cooling tower power consumption ratio is less than the closed cooling tower, but because of its circulating medium will be concentrated due to evaporation, must be dosed, replenishment, and easy to be contaminated, so for the emphasis on stability and continuous operation of process air-conditioning high-efficiency refrigeration station, more suitable for the use of closed cooling towers, especially in the northern region. 2.3 water pumps in the high-efficiency refrigeration station, the pumps of the energy consumption is second only to the water cooler, so a reasonable selection of water pumps For the energy saving of the cooling system is crucial. Should be based on system characteristics and pump characteristics curve for pump selection, while paying attention to ensure that the maximum efficiency of the pump in its longest running time within the range of conditions (load rate of 30% ~ 100%), rather than simply make the highest efficiency point in its design conditions. In the air-conditioning chilled water primary pump variable flow system control process, more use of differential pressure control system operation regulation, according to the system characteristics of a reasonable arrangement of differential pressure sensors can achieve different energy-saving effect, in the end of the system when the trend of load changes in the same way, differential pressure sensors are arranged at the end of the system control of energy saving effect is most obvious.
It can find the dynamic optimal power relationship between chiller units, pumps and cooling towers under different load demands, so that the overall energy consumption of the refrigeration station can be greatly reduced without decreasing the cooling capacity, successfully solving the problem of operating efficiency of the full frequency conversion refrigeration station and enabling the safe and stable operation of the refrigeration station.