1. Design of Clean Air Conditioning System and Frequency of Air Exchange in Clean Air Conditioning System
Class 100: 400 ventilation times per hour (cross-section wind speed 0.36m/s)
Class 1000: 80 ventilation times per hour
Class 10000: 40 ventilation times per hour
Class 100000: 25 breaths per hour
2. Clean room cooling load
Summer cooling load includes envelope structure load, personnel load, lighting load, production equipment load, fan load in air conditioning unit, fresh air load and so on. Among them, the production equipment is provided by Party A with equipment power and equipment exhaust. After calculation, the area index of the main clean room is 1170W/m2, and the area index of the cleaning room is 1220W/m2.
3. Fresh air volume and supply air volume of clean room
Fresh air volume takes into account the air volume required for personnel hygiene, the air volume of production equipment, and the air volume required to maintain positive pressure in the clean room. The air supply capacity of air conditioning in class 100 clean room is calculated by cooling load and enthalpy difference. In addition to the cooling load and enthalpy difference, the air supply capacity of the clean room below 1000 grade should also consider the number of clean air exchange and take the Zui value of both. The reason why it is different from Class 100 clean room is that the air conditioning mode is different.
Air-conditioning modes of class 4 and 100 main clean rooms (including cleaning rooms)
The PAHU+AHU+FFU air conditioning mode is adopted, in which PAHU is a fresh air treatment unit, AHU is an air treatment unit, FFU is a filter system with fan, PAHU is added to the filter system of fan. The positive pressure of clean room is controlled by the frequency conversion of PAHU fan motor. At the same time, the influence of the change of outdoor environment on clean room is reduced, which is beneficial to the control of temperature and humidity of clean room. Each workshop is an independent air conditioning system. The AHU of the purifying air conditioning unit will mix the return air extracted from the room with the fresh air treated by PAHU of the fresh air unit. After being filtered, cooled and humidified, it will be sent to the space on the ceiling of the clean room. Then it will be mixed with the indoor air returned to the ceiling by the return air technology and sent to the room by FFU. Local exhaust of production equipment is exhausted from exhaust fan to outdoor.

The air distribution in the clean room is one-way flow from top to bottom. The ceiling is basically covered with FFU air supply. The floor adopts an overhead floor with an opening rate of 18%, and some floors have control valves to regulate the air flow pattern.

Class 5,1000 dressing room and small cleaning room
The auxiliary clean workshop adopts the air conditioning mode of AHU plus terminal filter. When the cooling load and enthalpy difference of air supply volume are less than those of air exchange times, secondary return air is used to control the temperature and humidity of the clean room and reduce the initial investment of air conditioning units.
6. Air treatment
The fresh air in the clean room is filtered by PAHU and then sent to AHU after being treated by cooling coil. The cooling function of the cooling coil is realized by providing chilled water from the central cooling source when the fresh air needs to be dehumidified.
New and return mixed air is filtered, cooled, heated and humidified by AHU.
A. Cooling: The refrigerated water supplied by the central cooling source is cooled through the AHU coil.
B. Filtration: Air is filtered by primary and intermediate filters placed in AHU, and then sent to indoor by end filters.
C. Heating: The heating function is realized by the electric heater installed in the air supply pipe. The electric heater only plays an auxiliary role in this system.
D. Humidification: Dry steam humidifier humidifies the air through a steam nozzle installed in the air supply pipe. The humidifier is electrically heated and its water supply is RO water.
7. Cold Source Setting and Air Conditioning Water System
The screw chiller is used in the air conditioning equipment in the project. The refrigerant is R134a. The temperature of chilled water supply and return water is 7 ~12 ~C. The air conditioning water system is a primary pump variable water volume water system. The number of pumps is controlled according to the change of water volume in the system to realize the economic operation of the system. At the same time, there is a pressure difference bypass control between the supply and return water main pipes to ensure the constant pressure difference between the supply and return water and the evaporator of the water supercooler.
8. Automatic Control System
Frequency conversion automatic control is adopted for fan motor of Engineering fresh air unit. On the premise of ensuring hygiene, frequency converter is adjusted according to static pressure of clean room, so that static pressure of clean room does not change with the change of exhaust air volume of production equipment, and at the same time plays an energy-saving role. The project has high requirements for temperature and humidity. In summer, both cooling and dehumidification are realized by surface coolers. Therefore, the PID control method of temperature and humidity is adopted to output Zui large value. The frozen water volume of AHU and PAHU is controlled by equal percentage two-way electric regulating valve. Each AHU in the main clean room is responsible for a larger area, so each AHU is equipped with 2 to 3 temperature and humidity sensors to take the average value for automatic control of temperature and humidity. The dehumidification of air conditioning system is mainly accomplished by PAHU.
As a technical enterprise focusing on the design, research and development, construction and installation of hospital operating room purification, dust-free workshop purification, laboratory purification and other engineering projects in Shandong Province, Edward Purification has always been firmly on the road of professional purification engineering construction and development, and is a truly trustworthy professional operating room for domestic enterprises. Purification implementer! For more knowledge of medical purification industry, please pay attention to Wechat Public No. Aide-188 (Ed Purification and Oxygen Supply)