Through the design of the clean operating room air conditioning system, the design principle, design idea and design calculation of the air conditioning system have a great understanding and improvement. It enables the author to have a clear design idea, clear design principle and detailed design calculation ability in the future design process. Thus, the related design work of HVAC engineering can be completed systematically.
1. Project case information
Project information (provided by Beijing Zhongkesma) is as follows: According to the requirements of the construction unit, the Department of Clean Operations needs to construct a 100-level purification operating room (40 m2), three 10,000-level purification operating rooms (30 M2 each) and several 100,000-level purification auxiliary rooms (50 m2). The energy supply of the project is as follows: There is no other energy supply; the calculation parameters of clean air conditioning need to be understood; after zui, the relevant design specifications such as "Technical Specification for Building of Hospital Clean Operating Department" (GB50333-2002) and "Code for Construction and Acceptance of Clean Room" (JGJ71-90) should be followed.
2. Selection of engineering design load and equipment parameters

2.1 Selection and calculation of air conditioning load and equipment

Design and Calculation of Air Conditioning System for Class 2.1.1 100 Operating Room
According to the "Technical Specification for Building of Clean Operating Department of Hospital" (GB50333-2002), the size of laminar ceiling for air supply in class 100 operating room is 2600*2400mm; the average wind speed of the working face height section reaches 0.3m/s, considering the influence of wind speed attenuation, the air velocity of the air supply outlet for laminar ceiling is selected as 0.45m/s. (Air density is 1.2 kg/m3).
Summer calculation parameters of class 100 operating room (data):
(1) Relative humidity of outdoor air? W = 55% outdoor air enthalpy IW = 89KJ / kg. Dry air.
(2) Indoor air enthalpy iN=48KJ/kg.
(3) Considering the illumination, shadowless lamp, medical equipment, heat transfer of envelope structure and heat dissipation of medical staff, the heat load of the 100-level operating room is Q=40m2*225W/m2=9000 (W).
(4) It is assumed that there are 10 doctors and nurses working in the 100-level operating room at the same time.
According to the Handbook of Practical Heating and Air Conditioning Design, the amount of moisture dissipation per adult is 167 g/h.
Therefore, the wet load of class 100 operating room is: d = 10 (person)x 167g/h. person = 1670g/h = 0.464g/s.
The ratio of heat to humidity in the 100-grade operating room is equal to 19397 (J/g).
_Fresh air volume Gx = 0.34 kg/s.
The air supply capacity of the 100-grade operating room: G = 10108.8m3/h.
Considering the partial surplus of air volume, the actual selected air supply capacity is G=3.5kg/s.
In addition, the winter calculation parameters (data) of the 100-level operating room are as follows:
(1) Outdoor air enthalpy IW = 2.5KJ/kg. Dry air.
(2) The heat load of the 100-grade operating room is Q=-5000 (W).
(3) The ratio of heat to humidity in the 100-grade operating room is -10775 (J/g).
The other calculation parameters (data) are the same as those in summer.
Fresh air load QX = 5.8KW.
Air conditioning meter cooler load QK = 9.8KW.
The enthalpy-wet diagram shows that the moisture content at O and O'points is do=9.2g/kg.
Do'= 8.5g/kg.
Electric humidification D = 8.8kg/h.
Design and calculation of air-conditioning system for 21,000-grade operating room
According to the "Technical Specification for Building of Clean Operating Department of Hospital" (GB50333-2002), the size of laminar flow ceiling in 10,000-class operating room is 260*1400 mm; the air volume in single 10,000-class operating room is calculated by 22 times/h of ventilation (23 times/h considering certain surplus), area of 30 m2 and net height of 2.8 M. (Air density is 1.2 kg/m3).
Summer calculation parameters (data) of 10,000-grade operating room:
(1) Relative humidity of outdoor air? W = 55% outdoor air enthalpy IW = 89KJ / kg. Dry air.
(2) Indoor air enthalpy iN = 48KJ/kg. Dry air.
(3) Considering the illumination, heat transfer of enclosure structure and heat dissipation of medical staff, the heat load of the 10,000-grade operating room is Q=30 M2 *166.7 W/m2=5,000 (W).
(4) It is assumed that there are 8 medical staff working indoors at the same time during the operation in the 10,000-class operating room.
According to the Handbook of Practical Heating and Air Conditioning Design, the amount of moisture dissipation per adult is 167 g/h.
Therefore, the wet load of the 10,000-grade operating room is: d = 8 (person)x 167 g/h. person = 1336 g/h = 0.371 g/s.
The ratio of heat to humidity in 10000 operating room is 13477 (J/g).
_Fresh air volume Gx = 0.27kg/s.
_Air supply capacity of 10000 class operating room:
G = 0.64 kg/s
Winter calculation parameters (data) of 10,000-grade operating room:
(1) Outdoor air enthalpy IW = 2.5KJ/kg. Dry air.
(2) Considering the factors such as heat transfer of the envelope structure of the 10,000-grade operating room, the heat load of the 10,000-grade operating room is Q=30 m2*100 W/m2=-3000 (W).
(3) The ratio of heat to humidity in 10000 operating rooms is -8086 (J/g).
The other calculation parameters (data) are the same as those in summer.
Fresh air load QX = 4.5KW.
Air conditioning meter cooler load QK = 7KW.
Electric humidification D = 5.3kg/h.
Because the air-conditioning load and wet load of the clean auxiliary room are close to the parameters of the single operating room, the clean auxiliary room is also considered as a 10,000-class operating room for calculation. Therefore, the parameters of the clean air-conditioning circulating units of the 10,000-class operating room and the auxiliary room are four times as much as those of the single operating room.
The parameters of AHU-2 of clean air-conditioning circulating unit in 10,000-grade operating room and auxiliary room are as follows:
Air volume: 1932m3/h*4 = 7728m3/h; refrigeration capacity: 7.8KW*4 = 31.2KW; electric heating capacity: 2.8KW*4 = 11.2KW; electric humidification capacity: 5.3kg/h*4 = 21.2kg/h; external pressure: 800Pa 2.1.3 clean fresh air air conditioning system design calculation
The fresh air volume of 100-class operating room is 1000 m3/h, 10000-class operating room and auxiliary room is 800 m3/h*4=3200 m3/h. Therefore, the total fresh air volume is 4200 m3/h = 1.4 kg/s.
2.2 Design of air duct and water pipe
The air duct is made of galvanized steel plate, and the air duct insulation material is made of flame retardant PEF plate. The air duct is set in the ceiling interlayer; the size of the air duct should be controlled by the economic wind speed of the main air duct at 5-6 m/s and that of the branch air duct at 3-4 m/s; the cross-sectional area of the air duct (m2) = the air volume (m3/s)/wind speed (m/s); and the cross-sectional length-width ratio of the rectangular air duct should not be greater than 4:1.
In addition, galvanized steel pipes are used for water pipes in air conditioning systems, and flame retardant PEF pipes are used for heat preservation. The optimum diameter size of water pipe is to control the economic flow rate of water pipe at 1-2m/s. The design and hydraulic calculation of each pipe section are carried out by combining with the hydraulic calculation table.
2.3 Selection of Air Conditioning Equipment
Based on the results of the above design and calculation, the author carries out the following equipment parameter design and selection:
(1) There are 11 AHU-11 clean air-conditioning circulating units in class 100 operating room.
Air volume: 10500m3/h; refrigeration capacity: 38.5KW; electric heating capacity: 29.4KW; electric humidification capacity: 8.8kg/h; external pressure: 800Pa.
(2) There are 21 AHU-21 clean air-conditioning circulating units in 10,000 operating rooms and auxiliary rooms.
Air volume: 7728m3/h; refrigeration capacity: 31.2KW; electric heating capacity: 11.2KW; electric humidification capacity: 21.2kg/h; external pressure: 800Pa.
(3) PAU-1 parameters of clean fresh air air air conditioning unit are: 1.
Air volume: 4200m3/h; Refrigeration capacity: 57.4KW; External pressure: 400Pa
(4) One air-conditioning refrigeration and heating mainframe (air-cooled heat pump chiller and hot water unit).
Refrigeration capacity: 120KW.
(5) 2 centrifugal pipeline pumps.
Flow: 21m3/h; Head: 32mH2
3. Summary
In a word, through the design of cleaning air-conditioning system in a clean operating room of Shangrao hospital, the author has a great understanding and improvement of the design principle, design ideas and design calculation of air-conditioning system, which urges the author to complete the relevant design work of HVAC project systematically.
To learn more about the medical purification industry, please pay attention to Wechat Public No. Aide-188 (Ed Purification and Oxygen Supply)