Precision control system and method for air supply temperature and humidity of combined air handling unit

Abstract

The invention discloses a precision control system for an air supply temperature and humidity of a combined air handling unit. The system comprises the combined air handling unit, a control module, areturn air temperature and humidity sensor, a CO2 concentration sensor, a fresh air temperature and humidity sensor, an air supply temperature and humidity sensor and an outdoor temperature and humidity sensor. A control method comprises the following steps of a, calculating the cold load Q and the wet load W of an air conditioner area; b, determining the air supply capacity F and the frequency ofan air supplier omega; c, determining the air supply target moisture content ds'; d, determining the mixing ratio and mixing parameters of fresh air and return air; e, determining a control mode; andf, determining a control mode. As the fewer sensors are installed at the position where measurement accuracy can be ensured, the air handling process of the combined air handling unit is accurately calculated according to a controller built-in algorithm, and accurate control over the air supply temperature and humidity of the combined air handling unit and energy-saving running are achieved.

Description

technical field [0001] The invention relates to a system and method for precisely controlling the air temperature and humidity of a combined air handling unit. Background technique [0002] The combined air handler is a new type of combined air conditioner unit, which is manufactured by advanced CAD-aided design and production technology. It has the characteristics of compact structure, beautiful appearance, convenient installation and maintenance, good rigidity of the whole machine, and small air leakage. It can be widely used. It is suitable for industrial air conditioners such as electronic instruments, precision machinery manufacturing, textiles, chemical fibers, cigarettes, pharmaceuticals, food, power stations, light chemicals, etc. It is also suitable for commercial buildings, restaurants, supermarkets, theaters, gymnasiums, shopping malls, restaurants, hotels, and office buildings. Comfortable air conditioners for commercial and civil large and medium-sized public bu...

AI Technical Summary

Problems solved by technology

[0004] 1. Constant air volume control: The combined air handling unit operates at full load and full air volume, and relies on the temperature and humidity of the return air to adjust the cooling, heating, and humidification. This control method lags behind and does not save energy;

[0005] 2. Variable air volume control: a. Adjust the fan frequency according to the return air temperature to change the supply air volume; adjust the cooling capacity, heating capacity and humidification capacity according to the return air temperature and humidity. This control method lags behind, although it has a certain energy-saving effect , but the energy-saving space has not been fully tapped

b. On the basis of the above method, sensors are also installed in each functional section of the combined air handling unit to achieve precise control purposes. However, due to the particularity of the combined air handling unit, the measurement accuracy of the sensor cannot be guaranteed, so that true accuracy cannot be achieved control

[0006] To sum up, the existing combined air handling units mainly have the following disadvantages: (1) The constant air volume control does not save energy; (2) The control parameters are single, and the precise control of the temperature and humidity of the air supply cannot be realized; (3) A large number of sensors are required to support, Sensor measurement accuracy cannot be guaranteed, affecting the control effect

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