I、General Situation of Plastic Chemical Air Conditioning Purification Project
Production workshop has the most advanced CD-ROM production line, its production scale in the country is also second to none. It
is made of plastic as raw material, made every 2 seconds to produce a
CD-ROM speed of the production of DVD discs (containing data
information), and then after the formation of the cover printed on the
market after the sale of DVD disc products. The
production line for the introduction of foreign technology, is very
advanced, the introduction of 10 production lines; each production line
for an independent production of CD-ROM complete sets of equipment, the
entire production workshop 24 hours a day continuous uninterrupted
operation, with its high output rate, high quality Dvd discs, creating a good economic and social benefits, enriched the domestic information industry culture market. According
to the "Building Design Fire Code" requirements and the use of raw
materials in the production process, the plant is a fire hazard fire
II、Plastic Chemical Air Conditioning Purification Engineering Design Parameters
production workshop with a total construction area of 2963m2, the main
production workshop area of 1845m2, auxiliary production workshop area
of 1118m2, layer height 4.3m. Production workshop clean area air conditioning area of 1465m2, the design parameters:
Pressure plate workshop t = 22 ℃ ± 2 ℃ φ = 50% ± 5% 7 cleanliness
Printing workshop t = 22 ℃ ± 2 ℃ φ = 50% ± 5% 7 cleanliness
Comfortable air conditioning area t = 18-26 ℃ φ = 50-60% no level
III、Design of Cold Source System for Plastic Chemical Air Conditioning Purification Project
3.1, equipment summary
Chillers: screw, rated cooling capacity: 615kw, two, one with a prepared
Cooling tower: ultra-low noise counter-current, water 200m3 / h, two, one with a prepared
Water - water heat exchanger: corrugated plate, heat transfer capacity of 175kw four, dual standby
3.2, cold source water system
According to the production process equipment to provide the parameters, calculate the total cooling load of 598kw. CD-ROM production line in an important process requirements is 24 hours a day without interruption, cold source system, safe and reliable operation is the requirement to achieve the premise and protection. So the configuration of the cold source of the equipment according to a prepared to ensure that the equipment is reliable and continuous operation at the same time can reduce the wear and tear of equipment, to extend the service life. Chilled water (7 ℃), into the water separator is divided into three groups of water supply pipe leads, were sent to the end of the air conditioning equipment, comfort air conditioning terminal equipment, water - water heat exchanger three air conditioning chilled water Water point, after the occurrence of heat and moisture exchange by the three groups of water pipes collected in the collector, and then by the pump pressure into the chiller, the formation of chilled water circulation. Chilled water system constant pressure using sealed expansion tank constant pressure replenishment method. Cooling tower and other cold source equipment with the same room on the floor of the outdoor equipment, with reinforced concrete base height, the bottom of the water tray slightly higher than the cooling water pump inlet pipe, so that the water pump pipe always keep full flow; Installation of diversion muffler elbow.
IV、Design of Constant Temperature and Humidity Clean Air Conditioning System
4.1, plastic chemical air conditioning purification project air conditioning system
CD-ROM production workshop The main purpose of clean air-conditioning system is to control the production workshop in the air the number of dust particles, to ensure that the CD-ROM production environment cleanliness, improve product qualification rate and quality. Therefore, according to the two major production process of CD-ROM, respectively, set up two independent clean air-conditioning system: pressure plate workshop air conditioning system and printing workshop air conditioning system. The two systems are divided into their respective end air handling equipment.
4.2, air conditioning system division
4.2.1 All air purification air conditioning system. System flow chart. The air conditioning process is: fresh air - mixed with the return air - the beginning of the filter - table cold - electric heating - electric humidification - air - in the efficiency of filtration - the air conditioning system, Efficient filter air supply - indoor.
4.2.2 Production workshop ceiling with a high efficiency filter with a uniform orifice orifice, inside the wall back to the column below the single-louvers back to the air, and the outer corridor adjacent to the wall on the residual pressure valve. The air tissue is in the form of a turbulent top. The muffler is equipped with a return air main. The number of indoor ventilation is 20 times / hour.
4.2.3 Each process equipment in the production workshop has exhaust gas discharge, with independent exhaust system, dedicated to the roof of the centrifugal exhaust fan will be exhaust emissions to the atmosphere, the exhaust pipe higher than the roof 2m. In order to meet the clean indoor positive pressure value, in the combined air conditioning unit return section of the return air and fresh air inlet pipe are equipped with electric air valve. Indoor pressure are required for the pressure plate shop 15pa, printing workshop 10pa, between the two workshops and non-clean area to maintain 5pa differential pressure value, the two workshops and outdoor to maintain 10pa differential pressure value.
V、Auxiliary production room comfort air conditioning system
to the above two clean workshop, but also with the packaging workshop,
office, conference room, showroom, reception hall and other production
auxiliary space, are used fan coil plus independent fresh air system,
set a separate frozen water supply pipeline. Another
packaging workshop with a row of wind system to discharge the finished
product emitting the smell, fill the wind with the natural window into
VI、Automatic Control Design of Plastic Chemical Air Conditioning Purification Project
6.1 Control of modular air conditioning units
6.1.1 The air supply unit of the air conditioning unit is equipped with electric three-way regulating valve.
Through the installation of the temperature in the clean room wall sensor to detect the indoor temperature, feedback back to the signal, adjust the air conditioning into the air conditioning unit water cooler, and then supplemented by electric heating section of the temperature fine adjustment, in order to control the indoor temperature requirements. Similarly, through the installation of the humidity sensor in the clean room wall to detect indoor humidity, feedback back to adjust the opening of the three-way valve (dehumidification) or open the electric humidifier inlet pipe on the electric two-way valve (humidification) to achieve Control the indoor humidity requirements.
6.1.2 The exhaust of the production process equipment is intermittent, and the positive pressure in the room also fluctuates. Therefore, according to the feedback signal returned by the pressure sensor installed in the clean workshop wall, the fresh air valve and the return air valve The opening degree of the room to maintain the positive pressure.
6.1.3 Another guarantee the safe operation of the air conditioning unit, set the fan and electric heater chain control: that must be opened in the blower after the electric heater to put into use; when the blower stops, the electric heater immediately power. The initial filter section and the middle efficiency filter section are equipped with a resistance alarm. When the filter resistance exceeds the set value, the alarm will be reminded to clean the filter.
6.2 process of pure water cooling system control process Water itself by a dedicated water machine one-time preparation, stored in a pure water tank. When used, it is sucked from the pure water tank - pressurized by the pump - into the Class I plate heat exchanger (cooling water cooling) - into the second grade plate heat exchanger (chilled water cooling) - heat transfer within the production equipment - Back to the pure water tank, the formation of pure water circulation system. From the energy-saving point of view, the addition of the first-class cooling water heat transfer system, the main purpose is to use the cooling water temperature is low (winter and excessive season), can be pre-cooling of pure water, and then into the second grade chilled water The heat transfer system is cooled to the set temperature. Cooling return pipe and frozen return pipe are equipped with electric two-way valve, according to T3, T4, respectively, and T1, T2 size to control the electric valve opening and closing.
6.3 control of the cooling tower in the cooling tower of the main water supply installed on a temperature sensor, the measured water temperature higher than 30 ℃, the cooling tower fan operation; measured water temperature below 30 ℃, the cooling tower fan stop, to save Run the role of energy consumption.
6.4 Other air-conditioning control system also includes chillers, pumps, cooling towers and other equipment maintenance when the self-locking power control.
dust-free workshop air organization is very important, the conditions
should be designed to send the next side of the return air way, and to
ensure that the indoor air flow and air flow evenly.
7.2 reasonable to determine the principle of automatic control, is the constant temperature and humidity air conditioning system design key; the use of advanced automatic control system (the project uses the United States hollywell988 products) is completed after the project is put into use to meet the design requirements and daily operation and reliable , An important guarantee for stability.
7.3 At present, the clean room has been put into use, the air conditioning system is running well, the production situation to meet the expected requirements.