ba--Air conditioning System One pump and two pump difference

Generally speaking, the air conditioning system is designed according to the full load, but the actual operation, the full load operation time is less than 3%, the air conditioning equipment most of the time in the case of a far lower than the rated load operation. Under partial load, although the chiller can adjust the corresponding cooling output according to the actual load, but the flow configuration of the conventional cold water system in the evaporator side of the chiller is fixed, the chilled water flow of the system does not change with the actual load, and the energy consumption of the chilled water pump does not decrease with the actual load.

In the variable flow system, the chilled water flow of the system is not fixed according to the full load, but the water flow decreases during partial load, and the energy consumption of the chilled water pump decreases, thus achieving the purpose of energy saving and consumption reduction. Under the premise of fixed line system, the efficiency characteristic of the frequency conversion pump and the resistance characteristic of water system are close, theoretically the energy consumption of the pump and the flow rate are three times of the relationship, so the energy saving potential of the variable flow system is obvious. The main feature of the two-time pump variable flow system is that the traditional one-cycle pump of air conditioning system is divided into two stages. One pump is responsible for overcoming the resistance of the cold machine side, once with the water chiller one by one corresponding to the water pump design flow rate for the water chiller evaporator rated flow, through a reasonable calculation and selection, so that one pump operation in the best efficiency of the operating point. Two pumps are used to overcome the resistance at the end, can be set separately on different end loops, two pumps can be independently controlled according to the change of the loop load, variable frequency regulation.

When the system is large, the resistance is high, and the load characteristics of each loop is large, or the pressure loss is quite wide, if the use of a single pump, pump flow and head to the host flow and the most unfavorable loop of water resistance selection, configuration power is relatively large; part of the load operation, no matter how small flow and flow resistance, Pump also to full load with the operation, the pipeline excess flow and pressure head can only be used by the bypass and increase the valve resistance to be consumed, so the transmission of energy utilization is low, high energy consumption. If the use of two-time pump, two pump flow and head can be configured according to the different load characteristics of the loop, for the small resistance of the loop can be reduced once the pump set the head, to achieve "tailor-made", greatly avoiding unnecessary waste. and two times the pump setting does not affect the refrigeration host specified flow requirements, can easily adopt variable flow control and the free start and stop control of each loop, the load side of the flow regulation range can also be larger, especially when two times the pump adopts frequency control, its energy-saving effect is better. In the ultra-high-rise building, the use of two pump system, can also be used to cut the pressure of the pump head, reduce the pressure on the bottom of the system.

ba--Air conditioning System One pump and two pump difference