Calculating method of fresh return air mixed type air adjusting system with fixed secondary mixing ratio

Abstract

The invention relates to a calculating method of a fresh return air mixed type air adjusting system with a fixed secondary mixing ratio. The method comprises the following steps of: determining the dry-bulb temperature and relative humidity of an indoor design state point, the dry-bulb temperature and relative humidity of an outdoor design state point and the blowing temperature difference corresponding to the system design precision by determining the design calculating cold load and the design calculating wet load architectural indoors, wherein the fresh air percentage and the fixed secondary mixing ratio are target variables; acquiring the numerical values to calculate state parameter values of the indoor design state point, the outdoor design state point, a blowing state point, a primary mixing state point, a secondary mixing state point and state points of a dew point of a machine; and establishing a calculating mathematical model to calculate the general air volume, the fresh airvolume, the secondary mixing air return amount, the primary mixed return air amount and the primary mixed air volume of the system as well as a cooling capacity, quantity of reheat and refrigerationwater amount design numerical values needed by system design. The calculating method provided by the invention simplifies system control and operation complexity, and has relatively wide actual engineering application value.

Description

technical field [0001] The invention relates to a calculation method for a new return air hybrid air conditioning system with a fixed secondary mixing ratio, in particular to a calculation method for a new return air hybrid air conditioning system with a secondary mixing process in an air conditioning project, and the calculation determines the system The state parameter value of each state point and each design value of the system in the heat and humidity treatment process of humid air belong to the technical field of building energy conservation. Background technique [0002] With the rapid growth of the global economy and the increasingly urgent energy crisis, energy conservation and emission reduction have become one of the main issues that need to be faced by the whole world. According to relevant reports, my country's building energy consumption accounts for about 27.5% to 30% of the total energy consumption of the society, of which the energy consumption of the HVAC s...

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Problems solved by technology

[0003] At present, due to the existence of a reheating process in the wet air heat and humidity treatment process of the new return air hybrid air-conditioning system in the first mixing process, there is a serious energy waste phenomenon in which cold and heat cancel each other out, and the energy consumption is relatively large. However, due to the stability and simplicity of the humid air heat and humidity treatment process, it is more commonly used in practical engineering.

In the heat and humidity treatment process of humid air in the new return air hybrid air-conditioning system of the secondary mixing process, since there is no reheating process, the energy waste phenomenon that the cold and heat cancel each other is reduced, but when the residual heat is small or the residual humidity When it is larger, the dew point temperature of the machine during the humid air heat and humidity treatment process is significantly reduced, and the chilled water commonly used in the air conditioning system (the supply and return water temperature stipulated by the national standard is 7 ° C ~ 12 ° C) will be difficult to treat the humid air to the corresponding machine Dew point, resulting in insufficient dehumidification capacity of the system, it is difficult to meet the temperature and humidity control requirements, so it is only applicable to the actual project with a large heat-humidity ratio; The processing process also has the disadvantages of complex control process and stable operation completely dependent on the automatic control system, and the system pipeline layout is relatively complicated and difficult, so it is rarely used in actual engineering

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