】 【Weak current College on air-conditioning system design and construction --- Power By】 【China power house network.

<br> 1. the area between devices and storey and pipeline layout principles as intelligent buildings and the architectural features of the development, equipment layout required space increasingly restricted. The pipeline pipelines between devices only serious and reasonable space management, in order to save space .and avoid unnecessary rework. Equipment floor layout: 20 storeys of high-rise building: in the top or bottom set a device layer 30 storeys of high-rise building: in the upper and lower two devices layer 30 layers above super high-rise building .: in the upper, middle and lower respectively manufacturing plant to the device layer in its surrounding NYC hosted air-conditioning equipment in the room, chillers and boiler room equipment yishe in independent buildings. The device layer piping layout principles: ground h ≤ 2.0 m .layout air-conditioning equipment, pumps, h = 2.5 ~ 3.0 m layout of cold or hot water pipe h = 3.6 ~ 4.6 layout conditioning ventilation pipe mh> 4.6 m layout wire and cable equipment storey outline: building area (m2) device storey ( .m) building area (m2) device storey (m) 10004.0150005.530004.5200006.050004.5250006.0100005.0300006.5 in construction, often because the engine room space is insufficient or pipeline layout unreasonable, cause there is no air conditioning water valve block the installation location for .the installation of the valve is too high, I'm not in operation. 2. pump selection and installation in the design of the air-conditioning system should make the necessary calculations, calculated according to the design flow in the flow of pipeline of resistance ., to ensure that the selection of the pump head and reasonable. In the flow and head multiplied by a safety margin, the selection of a water pump. Some designers are not design calculation that head larger insurance, leading to the selection of the pump can .not meet the requirements, or result in increased operating costs, or even a water pump is not working properly. General project configuration of chillers are between 2 to 4, for large-scale projects, or even need 5 more than chiller parallel work. Cooling .stations of host and water pump of the match in General is a machine on a pump to ensure the water flow and water chillers, therefore, at present, China's air conditioning water system mostly have 2 sets of 2 or more pumps in parallel constant flow system .or a pump with variable flow system. Air-conditioning design, are based on maximum load condition for device selection to ensure that the most adverse circumstances. The circulation pump adopts parallel run mode, select the pump must press lines characteristics and water pumps in parallel .to the selection and calculation of characteristic curve. Selection, should take note of the pump in the design cycle time performance parameters, you should be concerned about the pump performance curve, try to select the pump performance curve steep parallel work. Run the personnel should .be aware of the conditions of the valve when converting. A lot of winter and summer air conditioning design is that dual-use of changes, with the season as the coil supply cold water or hot water. Winter thermal load than summer cooling load, and .air conditioning systems for water temperature from 5 ° c in summer General, winter from 10 ° c, depending on the conditioning system circulating flow calculation formula G = 0.86 Q / Δ T (Q-in-air conditioning load KW, Δ t is the .temperature ¡æ water system, G to water system circulating flow m3 / h), the summer air conditioning circulation water flow will be the winter of 2-3 times. So the water pump according to the summer working parameters selection. Pump installation, its .out of the inlet should install metal soft receive or rubber soft next, to reduce the effect of vibration on the pipeline, and protection of the pump. Weight greater than kg water pump should be installed inertia base and shock absorber. Inertia base generally used within .the framework of concrete-filled steel (C30) production. Inertial weight is generally based on the weight of 1.5-pump 2 times. Shock absorbers should be based on inertial basis weight and the weight of the water pump and water pump of dynamic load selection .. In addition to installing a water pump inertia level limiter. Water pump outlet sound exception, typically system resistance is too large to cause the system to water shortage. Solution: 1. Then open a water pump. Run two pumps, the noise disappears. .2. appropriate down pump outlet valve, the noise disappears. 3. the pump before the filter is too dirty, not on the water, take apart and wash the filter. 4. the exhaust system, reduce system resistance. 3. chilled water system .design and construction of 1. system frozen water (or water) flow estimation 0.14 ~ 0.20L / S (0.25 ~ 0.40L / S) / ton. 1RT = 3516.91W. .2. Frozen water system of water supply (expansion tank) water tank volume calculations: Vb = a △ tVs m3 Vb - effective volume expansion water tank (that is, from the signal pipe to the overflow pipe height difference between the volume) m3 < .br> A volume of water, a coefficient = 0.0006 L / ¡ .æ <br> ¡ .÷ T - the maximum water temperature change value ° c <br> Vs-system of water volume m3, ie the system of pipes and equipment in General any 3. Chilled water system flow requirements pipe DN100 and above: 2.0m / s ~ 3.0 .m / s DN80 ~ DN100 pipeline: 1.0m / s ~ 2.0m / s DN40 ~ DN80 pipeline: 1.0m / s or so DN40 following pipeline: 1.0m / s here anyway, chilled water system pipe flow should not be greater than 3.0 .m / s. The system is running or has just been turned on, the water is mixed with air, the system should be based on the pipe diameter is installed automatically on the valve. Special attention should be paid to the most vulnerable at the top .of the standpipe of the accumulation of air, impede the flow of frozen water properly, you must install automatically operable. For ease of maintenance, in the filter and valve Department should set the by-pass pipe, pumps and export Department, System lowest point .and the local low point drain valves to be located. Production plant in chilled water system if the system is large, terminal equipment more, proposed to use the same program system. You can avoid installing the hierarchical balancing valve, cost savings and easier to achieve .the hydraulic balance. Chilled water system piping the use of welding, welding slag and other debris are very easy to fall into the pipe, block filters or coil. SoAfter the installation is complete, you should make the pipeline cleaning, pipeline cleaning should be struck .to remove attached to the tube wall of welding slag and other debris. The system runs for the first time one week after washing the filters. Air conditioning pipe welding should be used as base for Argon-arc welding, welding head surface. Because the backing .for Argon-arc welding welding slag does not appear, and weld compact, no leakage. Frozen water system is run for the first time, you should first open water valves, water system is full, and then open the backwater valve in order to facilitate .the removal of impurities, prevent the pipeline into the coil. 4. the cooling water system design and construction of a refrigerator cooling water table piston type refrigerator (t / kw) 0.215 centrifugal chiller (t / kw) 0.258 absorption chiller (t / kw .) 0.3 screw chiller (t / kw) 0.193 ~ 0.322 cooling tower choices: 1. Now most central air-conditioning project use more is the low-noise or ultra-low-noise-FRP cooling tower, its counter-flow introduced code typically .DBNL-water (m3 / h). If DBNL3-100-100 m3 of water, says / h, the third redesign of ultra low-noise cooling towers of glass fiber reinforced plastic counterflow. Ie: the number of water (m3 / h .) = (host cooling capacity + compressor input power) ÷ 3.165 2. The cooling tower at the beginning of the first name flow should meet the requirements of the chillers, cooling water tower water inlet and outlet temperatures should be individually and chillers condenser outlet and .inlet temperature. Then, based on design and outdoor air in the wet-bulb temperature, check product samples for Tower thermal performance curve or instructions, check the actual flow tower are still not less than the chiller cooling water requirements. 3. check the selected .tower structure dimensions, run weight is suitable for field installation conditions 4. Brief experience value calculation formula: the amount of total cooling equipment (KW) × 856 (kcal) ÷ 3000 × (1.2 ~ 1.3) = cooling tower water cooling water system of .water supply are: 1 2 bleach water evaporation loss loss loss 4 3 sewage discharge loss recommended cooling water system of water supply for water for loop - 1.6% 1, electric refrigerator, water quality, taking small values, lithium bromide absorption refrigeration, poor water .quality, the max value. Cooling water system design issues 1. multiple cooling tower water, cooling tower parallel pipeline should set balance valve or electric control valve, balance line resistance. 2. cooling water system water quality is poor, you should design filtration system ., filtration and cooling water. 3. in a freeze dangerous areas, cooling tower of intermittent operation, to prevent icing, cooling tower water tank heating pipelines should be provided. Outdoor cooling water pipes should be insulated. Excessive cooling tower water bleaching is construction and .debugging of problems often encountered. The main reason for this is the flow of cooling water over rated. Adjustable condenser into and out of the water valves, water pressure gauges to observed pressure control in the rated range (typically about pressure to 0.08MPa), .generally you can solve the problem. If no, go to view the water distributor nozzle spray angle too down, adjust the cooling tower water distributor of spray angle, so it is slightly inclined (15 degrees). 5. condensed water system design and construction .often, depending on the unit's cooling load Q (KW) by the following data approximation of selected condensate pipe nominal diameter. Q ¡ .ü 7kWDN = 20mm Q = 7.1 ~ 17.6kWDN = 25mm Q = 101 ~ 176kWDN = 40mm Q = 177 ~ 598kWDN = 50mm Q = 599 ~ 1055kWDN = 80mm Q = 1056 ~ 1512kWDN = 100mm Q = 1513 ~ 12462kWDN = 125mm Q> .12462kWDN = 150mm Note: 1. DN = 15mm piping, not recommended. 2. the vertical pipes of diameter, and the level of the dry pipe diameters are the same. 3. condensate pipe nominal diameter DN (mm), should be based on .the flow of water through condensation calculations to determine the <br> Fan coil units, integrated air conditioner, air conditioner, running a combined process of condensation water, must be discharged in a timely manner. Emissions in the design of condensed water pipeline, keep .the following in mind: 1. Along the fluent direction, horizontal pipe should be not less than one thousandth of the slope; and water areas are not allowed. 2. when the condensation water plate is located at unit vacuum section, condensing coil outlet must .set the height of the water seal, seal than condensate tray at negative pressure (equivalent to the water column height) large 50 per cent. Water export, communicates with the atmosphere. In order to prevent condensation water pipe surface dew, Dew Proofing. 3 .. condensed water standpipe design at the top, should lead to pockets of the atmosphere. 4. the design and layout of the condensation water pipeline, you must carefully consider the possibility of regular washing and design arrangements necessary facilities. 5. large-scale electronic .workshop of MAU unit, AHU units because of the large water condensation, consideration should be given to recovery. Return water condensation water can do to supply water for cooling towers. Condensation water construction, pipeline installation must be careful not to pour the slope. In .many cases because of the down-slope of the condensate discharge properly, causing a spill water condensing coil Department. Installation height of the water bends should meet the design requirements, otherwise condensation water cannot be discharged. Condensate pipe laying on the ceiling, you should .seriously insulation to prevent condensation..