For a long time, in the electronics industry, temperature controllers are developing rapidly. Because it can flexibly control the start and stop of air conditioning units and indoor temperature in each region, and can save building space and engineering cost, fan coil (FCU) plus fresh air air-conditioning system has been the most semi-centralized air conditioning system type in hotels, hotels and office buildings where rooms and business rooms are rented out as the main business. The room air conditioning temperature controller is the key to control the cooling/heat supply of the end device, the fan coil unit (FCU), and realize the temperature control of the separate room and the energy-saving operation.
The general fan coil air conditioning temperature controller is basically an independent closed-loop temperature regulation system, which is mainly composed of temperature sensor, two-position controller, temperature setting mechanism, manual three-speed switch and hot and cold switching device. The control principle is that the air conditioner temperature controller generates a double-position control signal according to the comparison result of the temperature sensor measured room temperature and the set value, and controls the switch of the electric water valve (two-way valve or three-way valve) of the hot and cold water circulation pipeline, that is, by cutting off and opening the water circulation in the pipe, the supply air temperature (cooling amount) is adjusted.
** generation of air conditioning thermostat is mainly electrical products, the temperature sensor of air conditioning thermostat adopts bimetal sheet or pneumatic temperature packet, through the "given temperature disc" to adjust the preload to set the temperature, fan three-speed switch and seasonal switch for the splash type mechanical switch. Such air conditioning thermostat products generally have problems such as "the temperature setting index value is too thick", "the time constant is too large", and "the mechanical switch is easy to damage".
The first generation of air conditioning thermostat is an electronic product, the temperature sensor adopts thermistor or thermistor, the temperature setting and wind speed switch of some products achieve human-computer interaction interface through touch keys and liquid crystal display screen, the hot and cold switch is automatically completed, the operation amplifier circuit and the switching circuit achieve two-position adjustment. This kind of intelligent air conditioning thermostat products improve the human-computer interaction interface, solve the "temperature setting index value is too thick" and other problems, but there are still "control accuracy is not high", "time constant is large", "operation is more complex" and other problems.
At present, domestic and foreign manufacturers are researching and developing the third generation of intelligent room temperature air conditioning thermostat, and manufacturers actively respond to national policies, applying new control models and numerical control chips to achieve intelligent control. Now domestic manufacturers have produced intelligent room temperature air conditioning thermostat, and has been applied to practical projects. This production led to the development of the electronics industry.