Simulation of central air-conditioning microcomputer control laboratory equipment
Central air-conditioning has entered the homes of ordinary people. More and more people choose to live, work, play, and shop in the environment of central air-conditioning. With the development of the economy and the improvement of people's living standards; buildings equipped with central air-conditioning have mushroomed. Present in all corners of the city and countryside; ensure the normal operation of central air-conditioning, provide users with a healthy, comfortable, safe and civilized indoor environment; in view of the current shortage of talents and the generally low quality of air-conditioning operation, a large number of businesses are urgently needed Professional and high-quality talents; in order to solve the problem of lack of central air-conditioning teaching experimental equipment to train talents in major and technical secondary schools, the company has invested heavily in the development of central air-conditioning experimental equipment suitable for teaching by professional engineers. . ( Teaching Equipment | Teaching Instruments )
First, the salient features of central air-conditioning laboratory equipment:
1. It adopts fully transparent materials, and the mold is formed at one time, which is intuitive and helpful to teaching.
2. Reasonable overall design, beautiful appearance, simulation, and small size.
3. The refrigeration system and heating system are equipped with multi-level protection measures to ensure the safe and reliable operation of the equipment.
4. The refrigerating system adopts all copper material, which has good efficiency and long service life.
5, comprehensive functions, can be cooled and heated, and has an analog demonstration system, and all fault settings.
6. It has a microcomputer communication interface, which is convenient for remotely controlling the working status of the experimental equipment and collecting a number of related data.
The main technical parameters:
Working power: single-phase three-wire 220V ± 5% 50Hz
Power consumption: 2.5KVA cooling
Heating method: electric heating (adjustable)
Second, the characteristics and working principle of each major component
The system uses a fully-enclosed piston compressor. The normal operating temperature is only 0 ° C. It is safe and reliable, has a compact structure, low noise, and good tightness. The refrigerant is R22.
The refrigeration system uses a transparent water tank type evaporator, which is easy to observe. At a glance, the evaporator group is immersed in water, the preparation is evaporated in the tube, and water flows in the water tank under the action of the water pump to enhance the cooling effect.
The refrigeration system uses a spiral tube condenser, which is a newer type of heat exchange equipment. It is made of two parallel copper coils and is a spiral body with two spiral channels. The middle spiral is the cooling water channel, and the outer spiral is the channel of high-pressure refrigerant.
4. Spray cooling tower:
The condensing method of this equipment adopts a counterflow cooling tower. The mold is formed at one time and has a completely transparent structure. The suction fan is installed on the top of the tower. The structure is completely simulated and intuitive. The cooling tower adopts forced-air ventilation and the tower is filled with fillers. Improve the cooling effect; after the warm water from the condenser is pumped into the top of the tower by the cooling water, the nozzle of the water distributor rotates and sprays downward.
The boiler is the core component of the central air-conditioning heating system. Ingle's electric heating pipes are used to completely isolate water from electricity. It has over-temperature protection, anti-dry burning protection, and over-pressure protection to ensure human and machine safety. Imported polyurethane foam insulation Technology, good insulation performance.
6. Simulation room:
The simulation room is made of fully transparent plexiglass, which has a beautiful appearance, small size, small footprint, and compact structure. It has a fully transparent structure at a glance; the room is equipped with coils, coil fans, and temperature control regulators.
7. Temperature control:
The panel of the test bench of this equipment is equipped with a temperature control display instrument, which can control the temperature range, and the temperature of each key part is detected by the circuit.
8. Simulation demonstration:
This equipment is equipped with a 500mm × 300mm system working demonstration board, using epoxy copper clad board, four colors (red, green, blue, yellow), LED image, realistic display of the temperature and working status of cold and hot pipes.
9. Temperature controller:
The two analog rooms are equipped with digital display temperature control regulators, and the temperature range can be set by itself: the instrument can automatically adjust the temperature to the set value according to the specific conditions of the room temperature setting.
10. High and low voltage protection devices:
For safety reasons, the refrigeration system is equipped with high and low voltage protection relays to protect the normal operation of the compressor and the system.
11. Water tank:
In order to save water, the water resources of the system are recycled. The water tank is used to complete the tasks of adding, automatic adjustment, and filtration of media water. It is also equipped with an automatic water supply system. If the system lacks water resources, the water supply system will automatically start replenishment.
12. Central control section:
The overall control part of the experimental table can complete the tasks of switching between cooling and heating of the equipment, and closing in the cooling state or heating state. The startup mode is all micro-motion mode, which uses a weak switch signal to control the microprocessor and drive the circuit to work, thereby extending the service life of the device.
13. Failure demonstration experiment:
The experiment can directly demonstrate twelve failures of the refrigeration system and three failures of the heating system, and each failure is provided with a separate demonstration switch.
14. Features of microcomputer interface and control part:
There are two ways to control and display the parameters of the TX-KT2 central air-conditioning teaching experiment system. The first way is to control the working status of each part, set the parameters and Dynamic display. The second way is to communicate with the serial interface of the microcomputer through the serial port of the single-chip microcomputer (the main board of this experimental system uses today's advanced single-chip microcomputer as the main chip), and it is also equipped with all Chinese application software, so that the central air-conditioning needs The various controls and parameters that need to be displayed can be completed on the screen of the microcomputer.
<I> The software functions are as follows:
(1) Dynamic display of temperature at key points, including:
A. Current value of heating
B. Current cooling value
C. Boiler imports
D. Boiler outlet
E. Cooling tower inlet
F, cooling tower outlet
G, condenser inlet
H, condenser outlet
I. Evaporator inlet
J. Evaporator outlet
K, simulation room I
L. Simulation Room II
(2) The temperature setting and display temperature setting can be arbitrarily selected between 0 and 99 degrees Celsius.
(3) Compressor delay setting The compressor start delay can be arbitrarily set between 1-30 minutes.
(4) Switch control and instructions for the operation and stop of each part of the central air conditioner can be controlled by the switch set on the computer screen, and there is a switch display for remote operation. The set switches are as follows:
A, cooling water pump
B, cooling fan
C. Refrigeration water pump
E. Solenoid valve I
F, solenoid valve II
G, hot water pump
(5) Communication status display Equipped with the communication status and interface display of the experimental system and the microcomputer.
(6) Communication port selection The communication port between the experimental system and the computer has two serial ports to choose from, which are COM1 and COM2.
<二> Features of the computer software:
The software is a full Chinese menu, and the operation is very convenient and intuitive. You only need to click the mouse to achieve various switch controls and parameter settings. You can set and operate some functions without looking at the instructions.
All the functions realized by the computer software above can also be realized by the device of the control panel of the experimental bench.