light industry

一、summary
Haikang building central air conditioning control mainly by the third part mainly as: cooling pump control system (three 55kW motor, a dual-use preparation); frozen pump control system (Santai 45KW motor, a dual-use preparation); cooling tower fan control system (8 3KW motors).
In the central air conditioning system, the cooling water pump and cooling water pump capacity is based on the maximum design heat load of the building, and there is a certain design margin. In without the use of speed control system, pump throughout the year under power frequency state run at full speed, had no choice but to use throttle or return to regulate the flow, produce a lot of throttling or return loss and the pump motor, because it is running at full speed under high frequency, resulting in a big energy waste.
Due to the change of seasons, the outside temperature is different, in order to use the amount of guest room to make the heat load of the central air conditioning is far more than the design load in most of the time. That is to say, the central air conditioning is actually running in the low load condition for most of the time.
According to the above situation, we developed a set of HOPE-Z central air conditioning energy saving control system.

二、HOPE-Z central air conditioning energy saving control system function characteristic
1, high power saving rate
* power saving rate up to 50% - 20;
* use today's most advanced frequency control technology to coordinate the operation of the motor; microcomputer and intelligent instrument combination control, the application of the most advanced fuzzy control algorithm, to achieve the best energy use;
2, - high reliability -
* frequency converter and instrumentation on all the use of brand-name products;
* industrial level programmable controller and man machine interface for 24 hours monitoring;
* with over voltage, under voltage, over current, over load, lack of phase automatic protection function;
* the whole system is closed loop fuzzy control, there are parameters of self adjustment and adaptive function, automatic control algorithm according to the situation of the environment changes, to reduce the outage probability, there are human like intelligent efficacy;
3, - soft start characteristics -
* change the hard starting mode of the original motor, reduce the impact of the current to the electric surface, prolong the service life of the motor, reduce the vibration of the machine during the working process and prolong the service life of the air conditioning system;
* reduce noise and improve working environment;
4, - fool type operation -
All intelligent and digital instruments, friendly man-machine interface, with parameters and graphics records, all parameters have been adjusted, each boot and normal operation without adjusting parameters;
5, high rate of return -
All investment 18 to 8 months can be recovered by the savings of electricity
6, - good service -
* professional engineer 24 hours standby;
* one year warranty, life-long maintenance;
三、Energy saving control system of central air conditioning system
- pump, fan type load energy consumption analysis
Air flow, water flow regulation of fan and water pump is to rely on the traditional damper, throttle valve. When the needs of air and water is reduced, throttle valve, valve opening reduced: when the need to increase the air and water, damper and valve of the increase of the degree of opening. This adjustment is to increase the network loss, consume a lot of energy at the expense of the throttle valve. And usually in the design, the user design capacity of the fan pump is much higher than the actual need, the formation of a large horse drawn cart phenomenon, resulting in a large number of waste electrical energy. If the adjustment speed is used to regulate the flow, it can prevent the waste of power from the root. And the emergence of frequency converter makes the control mode into reality.
Fan and pump are the shaft power of the motor into mechanical energy of a machine, their starting torque is small, light load, with the potential for energy saving. The structure and working principle of the two are basically similar. To pump as an example to analyze its working principle and operation process. By the fluid mechanics, water Q and the speed of a square is proportional to the square of the speed of the pressure H is proportional to the power of P and the speed of the cube is proportional to.
Q1/Q2=n1/n2;
H1/H2= (n1/n2) 2;
P1/P2= (n1/n2) 3
By the above formula shows, if the efficiency of the pump, when the requirements of the regulation of water content decreased, speed can be decreased in proportion. At this time the pump shaft power is the decrease of cube. If the required air volume is reduced by 20%, the corresponding motor speed should be reduced by 20%, the actual speed of 80%, the real power for (0.8) 3 is about 51%, energy saving up to 50%

四、Working principle of air conditioning energy saving control system
Central air conditioning refrigeration units and fan system composition and refrigeration unit cooling water pump, chilled water pump, cooling tower pump and fan systems blower, air fan is square type load, on the one hand, due to the environment and the change of the load range greatly, and their selection left the big adjustment margin degree. On the other hand, the traditional of regulation is by opening the valve to control the process parameters, the waste of energy in vain. Frequency conversion transformation, all the valves are fully open, system, on the one hand, through the monitoring of air temperature, the PID regulator, regulating the rotation speed of the fan, air is controlled by the rate of heat exchanger, forming dynamic balance; on the other hand, temperature of circulation water system of central air conditioning monitoring system, to adjust the air conditioner of the actual output power. The system can according to the required temperature, automatic start / stop for pump units and adjust the pump speed, given the appropriate energy, thus the excess energy saved. When the outside temperature is raised, the water temperature of the central air conditioning system is increased by heat exchange, the system is monitored by the sensor, and the speed of the working speed of the pump is accelerated, and vice versa.
For chilled water system, due to the low temperature chilled water temperature is determined in evaporator operating parameters (general outlet temperature of chilled water for 7 DEG C), just control the temperature of chilled water in high temperature (return) can control the temperature, with temperature transmitter, PID temperature regulator and to form a closed loop control system of variable frequency device and a cooling water pump, cooling water temperature control at T1 (e.g. 12 DEG C), the chilled water pump speed corresponding to heat pumping load change and change.
For cooling water system and cooling on both sides of the condenser temperature as control parameters, the temperature sensor, PID temperature adjusting device and a frequency converter and cooling water pump to form a closed loop control system, cooling water temperature control in the delta T2 (for example, 5 DEG C), corresponding to the thermal load of the cooling water pump speed changes and changes, and the cooling water temperature is maintained in the settings unchanged, enables the system to meet the main engine working condition under the condition of constant and cooling water pump system energy.
HOPE-Z central air conditioning energy saving control system, not only the operation is convenient, simple, maintenance amount is small, but also has the remarkable energy saving effect. And to achieve a high degree of automation, to improve the quality of air conditioning. Ensure process production needs, achieve better energy efficiency. On the principle of the intelligent instruments such as model frequency made according to, not only to enhance the monitoring and protection functions of the system, and power-saving rate is as high as 20 - 50%, 8 to 18 months of recovery of investment cost, economic benefits particularly evident.

五、equipment investment
Unit name specification from the serial number of the device quantity unit price (yuan) price (yuan)
No. 11 line 1800*800*600 1 sets of Changsha cabinet
No. 22 1800*800*600 Changsha 1 sets of control cabinet
No. 33 1800*800*600 Changsha 1 sets of control cabinet
No. 44 1800*800*600 Changsha 1 sets of control cabinet
total
Special note:
1, the number of control cabinet has two sets of 55KW inverter; 3 control cabinet has two sets of 45KW inverter, 4 control cabinet has eight 3.7KW inverter.
2, the control system for the central air conditioning control system, the use of variable frequency greatly save the cost of the transformation of the two. Investment benefits, with great effect. When the system is used in all kinds of speed regulating system, the energy saving effect of the system is 5 - 35%, which is not affected by other factors.