【 Weak current College 】 LIBR absorption chiller cooling system design---Power By 【 China power house network 】

Air conditioning cold water pipe system can be divided into: closed and open systems; dual-control and four control; with the program and return; and the next fraction on fractional; single pump and double pump, etc. Press run adjustment method to distinguish between the fixed and variable flow system.

A closed-loop and open-loop

1. closed-cycle system

Piping systems for non pressure and atmospheric water system, the highest point in the system of contact set expansion tank and exhaust and discharge devices of the system. See Figure 6-l shows.


When the air conditioning system with fan-coil units, air conditioners (belt coolers) for cooling, cold water system the use of closed-system. High-rise building closed systems should be adopted.

Closed cooling system refrigerator evaporator should be closed and refrigerator energy regulation should meet the air-conditioning load changes. General air conditioning system load changes in 100% ~ 20%, the number in the selection of refrigerating machines and single energy regulation, to consider this issue.

Hot water system, generally as a closed-cycle system. At design time to consider direct-fired LIBR absorption chiller in low load heating possibilities. Such as low-and heating load when not possible, you should consider other measures (e.g., electric heater, etc.).
The advantages of closed-loop:

(1) pipeline and equipment not corrosion;

(2) not required for lifting height of hydrostatic pressure, pressure low circulating water pump, water pump power small,

(3) in the absence of water storage tanks, without gravity return water, backwater without a separate pump, etc., thereby investment, system simple.

The disadvantage of closed cycle;

(1) cool ability small, low-load, the refrigerator is constantly in motion.

(2) expansion tank of water sometimes additional compression pump.

2. open the circulatory system

Pipeline between the tank (or water) through the atmosphere, since the stream and backwater (gravity return water), the pipeline passes the air systems, see Figure 6-2.


Air conditioning system with cooling air washers should adopt open system. Air conditioning system with cooling water coolers, cooling water temperature fluctuation in small or refrigerator energy regulation cannot meet air conditioning systems of varying loads, or open system. When using the open-water tanks storing cold or water to reduce peak loads, the use of open-type system.

The advantages of open system is cold water tank has some cool capabilities, you can reduce the amount of time, open the refrigerator to increase capacity for energy regulation and cold water temperature fluctuations can be smaller.

The drawback is:

(1) cold water and atmospheric corrosion of piping, easy contact;

(2) lower washer as, not directly from the stream back to the cooling machine room, you will need to add back into the pool and back pump;

(3) user (washers, coolers) and refrigeration room height difference is large, the pump is poor to overcome high hydrostatic pressure, higher power consumption;

(4) the introduction of artesian water, return pipe diameter, and investment.

The second two controls, three control, four control

For fan-coil units, air conditioners, heat and cold common table coolers of hot and cold water supply is divided into two, three and four control. See Figure 6-3.


1. only require winter heating and summer cooling system; as well as year-round air conditioning system, the entire water system does not require some of the rooms have heating and cooling of rooms, you can press the season for cooling and heating of the conversion, you should use two control closed system.

2. when the cooling and heating load alternate frequently or different rooms at the same time require cooling and heating, to adopt the four control system.

3. three control due to cold and heat losses, control more complex, are generally not used.

4. for usability have strict requirements for temperature, humidity, air conditioning system is generally hot and cold water system are set separately