Fan coil on-demand control system and control method thereof

Abstract

The invention relates to the technical field of building energy conservation and air conditioning ventilation control, and concretely relates to a fan coil on-demand control system and a control method thereof. Temperature sensors are arranged at an air supply inlet and an air return inlet of a fan coil; a coil water inlet pipe is provided with an electrically operated valve and a micro control cabinet; and the micro control cabinet controls operational taps of a fan and on-off of the electrically operated valve of the coil through calculating a room required airflow according to air supply / return temperature, so that on-demand air supply of the system is realized, the thermal comfort of a room is improved, and meanwhile, the system is ensured to operate in a high-efficient and energy-saving way. According to the fan coil on-demand control system and the control method thereof provided by the invention, on one hand, the operational taps of the fan are directly controlled by the fan coil on-demand control system through the required airflow, so that the thermal hysteresis is less, the control response is fast, and the room comfort is higher; and on the other hand, the fan taps and the on-off of the coil valve are automatically adjusted by utilizing the micro control unit, so that the fan coil system is automatically on-demand controlled and operates in the energy-saving way, stable to operate, and high in automation degree.

Description

technical field [0001] The invention relates to the technical field of building energy saving and air-conditioning ventilation control, in particular to an on-demand control system for a fan coil unit and a control method thereof. Background technique [0002] At present, the semi-centralized air conditioning system mostly adopts the fan coil system. The conventional fan coil system generally adopts simple control or temperature control, among which simple control is to use the three-speed switch to directly manually control the variable speed operation and start and stop of the fan according to the change of the room load (temperature). Inconvenient, unable to maintain a constant room temperature, low automation. The temperature control is to use the indoor constant temperature controller to collect the indoor (return air) temperature and compare it with the set value to control the fan gear position of the fan coil system or the on-off of the coil water flow, so as to adj...

AI Technical Summary

Problems solved by technology

Conventional fan coil systems generally adopt simple control or temperature control. The simple control is to use the three-speed switch to directly manually control the shifting operation and start and stop of the fan according to the change of the room load (temperature). This control method has low precision and is difficult to operate. Inconvenient, unable to maintain constant room temperature, low degree of automation

Temperature control is to use the indoor thermostat controller to collect the indoor (return air) temperature and compare it with the set value to control the fan gear of the fan coil system or the on-off of the coil water flow to adjust the air supply volume or temperature of the room. , and then keep the indoor temperature constant. This method is simple to control, but because it is only controlled according to the return air temperature, the fan coil system has a large thermal hysteresis, slow response, and prone to overshoot, which cannot achieve on-demand ventilation. Control The effect is poor, there are large temperature fluctuations in the room, and thermal comfort cannot be guaranteed; in addition, the on-off control of the coil with this method has low precision and slow action, and often fails to achieve the expected control effect

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