Weak current College】 【compressor considerations when connected in parallel.

<br> <br> 1. maintain oil surface <br> 2. back to the solution of <br> 3. protective devices? parts department products plant <br> 4. confirmation of piping stress <br> (Which maintain the oil .surface is the most important issue) <br> <br> 1 keep the oil surface (1) <br> <br> Compressor parallel use, because the compressor oil quantity and volume of the oil system, long operation will cause the compressor for .oil changes (party oil surface reducing, rose oil face a party). If】 【drawing 1-1. <br> <br> <br> Connect to the same type of compressor A and b, if the compressor of A oil is .high and the system back to A small quantity of oil, the oil surface will continue to decline, finally appear almost no oil State, causing the damage caused by poor lubrication bearings. Compressor oil quantity of B, and the system back to oil a large .quantity of oil, B will continue to rise, the last motor rotor almost submerged in oil inside, causing the input power increases, the portion of the increase in temperature. <br> <br> Parallel compressor runtime changes the oil surface (= oil .quantity side to the other side of the compressor) is called [partial oil]. The worst time, dozens of minutes to appear on the other side of the compressor oil free. <br> <br> <br> 1 keep the oil surface .(2) <br> <br> Try to make each compressor oil quantity equal to the amount of oil equal suction line, you can extend a State without oil, but these measures are not fully offset the Elimination of compressor oil. <br> .<br> Maintain oil surface method <br> <br> ☆ The design is not susceptible to partial oil system <br> <br> ☆ Occurred after partial oil, we must take the compressor oil back to the initial state of design. < .br> <br> 1 keep the oil surface (3) <br> <br> Avoid partial oil strategy is: <br> <br> ① the same model, with the capacity of the compressor connection, as far as possible on the .oil quantity equal to the amount of oil. / <br> <br> ② compressors of the exhaust pipe to the confluence of the Department, as well as the differences between the Department of the suction line to the compressor, each system's parts are the .same shape, 2 compressor to maintain parity of the refrigerant + oil flow. <br> <br> ③ for further restraint systems on oil, gas pipeline design oil separator, it is best to adopt separation into two compressor oil back into the system < .br> <br> These three strategies ① and ② ③ is must, is necessary. Effect is obvious) <br> <br> 1 keep the oil surface (4) <br> <br> Some time after the operation are oil operation .<br> <br> Both the oil operations, buildings can through both sides of the exhaust pipe, the compressor suction tube for all oil can even work?, very long time. <br> <br> »Effective way is through tubing connection .2 compressor oil storage location, move the oil through tubing. <br> <br>? Both oil operation of representativeness, through the following order for a short time both compressor ON-OFF (Note 1), correct partial oil. 【Figure 1 .-2】 <br> <br> <br> ① stop a compressor (OFF), 2 minutes: oil will move through to the operation of both tubing (ON) side of the compressor <br> <br> ① ② instead of .ON-OFF relations in 2 minutes: oil will move through to the operation of both tubing (ON) side of the compressor <br> <br> ③ restored to their original running state (both restored to operation status (ON)) <br .> <br> Use the attention of the tubing <br> <br> <br> Note that if you set both operate in the conventional oil, oil level changes will accelerate (Note 2). Not all tubing, oil surface only through the .exhaust pipe and suction tube slowly changes. However, the settings are tubing, normal operation and also through tubing oil flow, causing oil level changes to speed up the phenomenon. This problem, you need to reduce both oil operation interval or have installed solenoid valve .tubing, only allow operation connected are some solutions such as tubing. <br> <br> <br> Note 1: <br> 1) here is an example of setting frequency, frequency + fixed-frequency connection, the frequency has been ON .status, frequency of repeated for low-speed operation (oil from variable to fixed-frequency) and high-speed rotation (oil moves from fixed frequency inverter) are oil. That is, by repeatedly changed sides of oil pressure size for both oil. .<br> <br> 2) extend the party compressor stop time, running side of refrigerant gas compressor will be condensed in stop logging on the compressor of the exhaust system, affecting the trust of measuring the compressor is stopped. So you want to shorten .the stop time. <br> <br> Note 2: <br> Through tubing for oil mobile can be explained by the fact that both sides have save oil pressure difference (1/1000MPa degree of variance), and through this pressure difference, .the compressor oil in a large number of fine particles can move. Fine oil is very light, even slight pressure difference you can also move, you can drop in a short time to cause poor lubrication the oil surface. <br> <br> 2 .back to the solution of <br> <br> Too avoid partial earlier in important matters, oil pipeline shape equalization to reduce excessive back to fluid phenomena is also very important for the design project. If the pipeline shape, lead to the two sides back .to fluid, will be back up many occurred within the compressor, as well as liquid compression to reduce the oil concentration causing poor lubrication. <br> <br> In addition, the shape of the suction head separation is also a back-up of .the major issues of equality. Than simple T words separately, fluid can be divided in sleek Y words separately more ideal. 【Figure 2-1】 <br> <br> <br> <br> Whether due to fluid cause liquid compressed confirm ., you need to stop by for a long time, after defrosting time IN and OUT of the machine to confirm. No matter which one, you need to consider the refrigerant filling quantity of maximum deviation, and the short pipe is in need of strict consideration .and implementation. <br> <br> 3 protection device accessories parts of equipment (1) <br> <br> Often running 2 compressor (both oil operation is another), but also to the ability to adjust to only operate when one compressorWait ., so the protection devices and accessories from different parts of the configuration. <br> <br> Only do while running, it is best to 2 compressor has shared 1 high voltage protection (HPS), low-voltage protection (LPS). But .exhaust pipe temperature protection of each compressor must be installed. Compressor motor protection (IP) and the crankcase heater bands also needs to be installed separately. All tubing due to use of the electromagnetic valve set (reference 1) <br> <br> Above .,】 【Figure 3-1 represents only at the operation of connection points. <br> <br> <br> <br> 3 protection device accessories parts of equipment (2) <br> <br> Only running one compressor, first ., you must stop the side of the compressor installation globe valve exhaust pathway. You can prevent stop when the countercurrent and refrigerant condensing, put liquid refrigerant compressor. (1 * Note 1 Reference) <br> <br> High-voltage protection (HPS .) need individual installation, low-voltage protection (LPS) preferred shares for 1 low-voltage protection. Exhaust pipe temperature protection must be an individual installation. Compressor motor protection (IP) and the crankcase heater bands need individual installation. All tubing due to .use of the electromagnetic valve set (reference 1) <br> <br> Above,】 【Figure 3-2 indicates a party to the operation of connection points <br> <br> <br> 4 confirmation of piping stress <br> .<br> Because of the connection tubing is complicated, the system has been added, so it is best to conduct oil piping system stress damage to confirm. <br> <br> The following instructions to confirm the stress profile 【Figure 4-1 .】. <br> <br> <br> <br> (1) stress confirmation <br> <br> Stress confirmation, you must use the stress table from physical measurement <br> <br> First of all, the real start .measurement, it is a good idea to do a piping system stress analysis, confirm that the stress concentration point (= install stress table place) where stress is centrally, <br> <br> Piping of the root of the fixed part (example: .compressor shell, contact Department, etc.) → 【Figure 4-1】 ○ parts <br> <br> Piping fixed part of the first bending Department → 【Figure 4-1】 △ section <br> <br> The determination of .parts requires X, Y2 direction determination】 【Figure 4-2. <br> <br> <br> <br> (2) the recognition criteria for the determination of the kind <br> <br> Real confirmation, in standard conditions .running conditions. <br> <br> ☆ The compressor ON or OFF "introduction start stop time", whether dramatic stress, whether occurring more than piping materials elastic limit stress? (example: stop state two compressor at the startup and operating conditions are .oil has only one compressor start stop) <br> <br> * Power supply voltage, nominal + 10% (compressor start torque max) <br> <br> ☆ Compressor stability operation, whether because of the piping system produces more than pipe .resonance material fatigue limit stress? (example: two simultaneous operation of compressor and party operation) <br> <br> * Power supply voltage, rated ± 15% (in order to master the resonance of deviation) <br> <br> < .br> <br> (3) reduce stress concentration (stress too large of countermeasures) <br> <br> Reduce stress, generally have the following. (Must be in the actual piping system seek solutions) <br> <br> < .br>? Reduce the weight of the piping system <br> <br>? Design can absorb stress of bending and cyclic Department <br> <br> The Department of buildings increased bending bending radius <br> <br> <br> Case .1 <br> <br> This connection is using high-pressure Chamber compressor system. For low pressure compressor system, cavity must connect back to the tubing between the compressor. <br> <br>? This figure can be reduced to one oil .separator, installed in the main exhaust pipe, use Y-type connections, and then return to the compressor oil, respectively, in <br> <br> This kind of structure of benefit that can be both run interval lengthen oil <br> < .br>? This form easily overheat operation, the operation of the compressor will be reduced. <br> <br> <br> Case 2 <br> <br>? If you use this low-pressure Chamber compressor map you want to breathe .in the dispenser for special handling, deliberately let A pressure higher than in the low pressure compressor B low pressure compressor pressure refrigeration oil flow to A one-way from B compressor. <br> <br> Moreover, in the form of A compressor- .based compressor, B supplement compressor (B cannot separate operations), <br> <br>? There are pressures because B compressor deliberately reduced, causing b COP is relatively low, generally do not use; <br> <br> <br> .<br> <br> <br> <br>.