谷轮涡旋压缩机故障现象
谷轮涡旋压缩机高温保护
谷轮涡旋压缩机高温保护谷轮涡旋压缩机高温保护引言:随着工业技术的不断发展和进步,涡旋压缩机在许多领域中扮演着重要的角色。
谷轮涡旋压缩机作为一种高效能,无油润滑、无脉动、无振动、噪音低、运行可靠等特点的压缩机,被广泛应用于制冷、空调、石油、化工等领域。
然而,由于工作环境和操作条件的限制,谷轮涡旋压缩机在运行过程中很容易发生高温问题,而高温问题对设备的寿命和性能造成了严重影响。
因此,针对谷轮涡旋压缩机高温问题的研究成为了一个热点话题。
什么是谷轮涡旋压缩机高温保护?谷轮涡旋压缩机高温保护是指在设备运行过程中,通过一系列的控制措施和技术手段,及时发现设备发生高温现象,采取相应的措施来保护设备的正常运行。
谷轮涡旋压缩机高温保护的目的是防止设备因超温而损坏,提高设备的可靠性和使用寿命。
谷轮涡旋压缩机高温问题的原因:1.功率过剩:谷轮涡旋压缩机在运行过程中受电压、电流等因素影响,当设备承受过大的功率时,容易出现高温问题。
2.冷却不良:谷轮涡旋压缩机在工作过程中需要进行冷却,如果冷却系统出现问题,如制冷剂流量不足、冷却器堵塞等,就会导致设备高温。
3.润滑不良:谷轮涡旋压缩机是一种无油润滑的压缩机,如果涡旋机内的摩擦部分润滑不良,就会产生过多的热量,导致设备高温。
谷轮涡旋压缩机高温保护的方法:1.监测和调整电流:通过监测谷轮涡旋压缩机的输入和输出电流,及时判断是否过载,调整电流来保护设备。
2.改善冷却系统:优化冷却系统设计,提高制冷剂流量,增加冷却器数量等措施,改善冷却性能。
3.优化润滑系统:改善润滑系统的设计,确保涡旋机内各个部件的摩擦表面良好润滑,减少摩擦产生的热量。
4.安装温度传感器:在谷轮涡旋压缩机关键部位安装温度传感器,及时监测设备的温度变化,一旦达到设定的高温值就采取相应的保护措施。
5.设定工作温度范围:根据涡旋压缩机的使用环境和特点,设定一个适应的工作温度范围,超出该范围采取保护措施。
谷轮涡旋压缩机高温保护的效果:谷轮涡旋压缩机高温保护的实施对改善设备运行状态和提高设备寿命具有显著效果。
压缩机常见故障分析及处理方案
压缩机常见故障分析及处理方案压缩机是工业生产中常见的设备之一,常用于将气体压缩成高压气体,以满足不同领域的需求。
然而,压缩机在长时间运行过程中可能会出现各种故障,影响工作效率和设备寿命。
下面将从常见的故障类型开始,分析和提供处理方案。
1.压力不稳定或无法达到要求:这种故障可能是由于气源问题或压缩机内部问题引起的。
首先,检查气源排气管路是否堵塞或漏气,修复问题。
如果排气管路没有问题,则需要检查压缩机是否存在密封不良、活塞磨损、气阀故障等问题。
如果发现了以上任何问题需要及时更换或维修。
2.压缩机噪音过大:噪音过大可能是由于压缩机内部零件松动、螺栓松动、风扇磨损等引起的。
此时,需要停机检修,检查和紧固相应松动的部件,如螺栓、风扇等。
若发现零件磨损过度,则需要更换。
3.压缩机过热:当压缩机温度过高时,通常是由于冷却系统故障引起的。
首先,检查冷却风扇是否正常运转,清洁或更换损坏的风扇。
其次,检查冷却油是否充足,若不足则添加合适的冷却油。
最后,检查冷却器是否堵塞,并进行清洁或修复。
4.压缩机油液或水分过高:油液或水分过高可能导致润滑不良,进而引起部件磨损。
此时,需要更换润滑油,并检查冷凝水排放系统是否通畅,清理或维修。
5.压缩机运行时间过长:当压缩机运行时间过长时,可能是由于过大的负载或过低的冷却导致的。
首先,检查负载情况,适当减小负载以降低运行时间。
其次,确认冷却系统正常工作,提高冷却效率。
最后,定期检查和维护压缩机,确保部件的正常工作。
6.压缩机排气温度过高:过高的排气温度通常是由于过大的负载或冷却系统故障引起的。
首先,检查负载情况,减少负载或增加辅助冷却设备。
其次,检查冷却系统,确保冷却效果良好。
如果以上方法无效,可能需要更换适合负荷的大功率压缩机。
总之,压缩机在长时间使用过程中常常出现故障,处理故障需要综合考虑多个因素。
定期的维护保养和及时的故障检修是保证压缩机正常运行的关键。
此外,操作人员要熟悉压缩机的工作原理和常见故障处理方法,提前做好预防和应对措施,以确保生产过程的顺利进行。
涡旋压缩机的特性与应用技术
11.适用范围:
一切所以R
22、R134a、R
404A、R
407C、R410的蒸发xx制冷系统
12.压缩机保护器件
压力控制器由于涡旋压缩机有时高低压会快速平衡,对于要求抽空停机的系统需要配合温度控制器或电气延时控制
建议配置相序和缺相保护器(除ZB92KC,ZB11MC和ZF24以上压缩机外)建议配置吸气过滤器防止杂质进入压缩机损坏压缩机涡盘
ZF压缩机的结构和ZB压缩机的异同
最佳蒸发温度范围:
+10℃--40℃(R22和R404A)
吸排气口全部是螺纹连接
全部带油视镜
ZF24以上压缩机都有保护模块
所有ZF压缩机都有喷液冷却口:
ZF18以下压缩机配喷液阀,ZF24以上压缩机配喷液组件(须另配”电磁阀)
其余和ZB型压缩机基本相同
ZF压缩机的低温性能特别好,超过半封闭碟阀压缩机
润滑油失效压缩机运行时视油镜中可见润滑油发黑,低压表压力正常,短时运行系统降温正常压缩机曾经发生过热导致润滑油碳化,系统太脏导致润滑油变性更换润滑油
19.液击
加入太过量的制冷剂压缩机剧烈震动,声音很大立即停机,释放制冷剂至0.3-
0.4MP表压,再次开机,缓慢加入制冷剂,重新调试通常压缩机不会坏
20.压缩机故障及损坏
17.电源跳闸
压缩机刚启动就跳闸电源问题,检查交流接触器或空气开关
压缩机不转,测量显示3相阻值不平衡,绝缘电阻很小压缩机线圈坏
18.压缩机过热原因
回汽量不足排气温度高、高压表压力不高
制冷剂充注太少视液镜中制冷剂不连续,有气泡;(可略多加,不可少加)膨胀阀太小低压表压力偏低,相应蒸发温度低于允许范围(膨胀阀选择留有余量)
谷轮ZW系列(中间补气涡旋)压缩机应用指南
AE4-1381May 2011ZW21 to ZW61KAE and ZW30 to ZW61KSECopeland Scroll® Water Heating CompressorsTABLE OF CONTENTSSection Page Section PageIntroduction (2)ZW**KA Application (2)ZW**KS ApplicationVapour Injection - Theory of Operation (2)Heat Exchanger and Expansion Device Sizing (3)Flash Tank Application (3)Intermediate Pressure and Vapour Injection Superheat (3)Application ConsiderationsHigh Pressure Cut-Out (4)Low Pressure Cut-Out (4)Discharge Temperature Protection (4)Discharge Temperature Control (4)Discharge Mufflers (4)Oil Dilution and Compressor Cooling (4)Electrical Considerations (5)Brazing and Vapour Injection Line (5)Low Ambient Cut-Out (5)Internal Pressure Relief Valve (5)Internal Temperature Protection (5)Quiet Shutdown (5)Discharge Check Valve (5)Motor Protector (5)Accumulators (5)Screens (6)Crankcase Heat-Single Phase (6)Crankcase Heat-Three Phase (6)Pump Down Cycle (6)Minimum Run Time (6)Reversing Valves (6)Oil Type (7)System Noise & Vibration (7)Single Phase Starting Characteristics (7)PTC Start Components (7)Electrical Connections (7)Deep Vacuum Operation (7)Shell Temperature (7)Suction & Discharge Fittings (7)Three Phase Scroll Compressors (8)Brief Power Interruptions ..........................................8Assembly Line ProceduresInstalling the Compressor (8)Assembly Line Brazing Procedure (8)Pressure Testing (8)Assembly Line System Charging Procedure (8)High Potential (AC Hipot) Testing (9)Unbrazing System Components (9)Service ProceduresCopeland Scroll Functional Check (9)Compressor Replacement After Motor Burn (10)Start Up of a New or Replacement Compressor (10)FiguresBrief Product Overview (11)ZW21KAE Envelope (R-134a) (11)ZWKAE Envelope (R-407C, Dew Point) (12)ZWKA Envelope (R-22) (12)ZWKS Envelope (R-22) (13)ZWKSE Envelope (R-407C, Dew Point) (13)Heat Pump with Vapour Injection – EXV Control (14)Heat Exchanger Schematic (14)Heat Pump with Flash Tank (15)Possible Flash Tank Configuration (15)Oil Dilution Chart (16)Crankcase Heater (17)Compressor Electrical Connection (17)Scroll Tube Brazing (17)How a Scroll Works (18)IntroductionThe ZW**KA and ZW**KS Copeland Scroll®compressors are designed for use in vapour compression heat pump water heating applications. Typical model numbers include ZW30KA-PFS and ZW61KSE-TFP. This bulletin addresses the specifics of water heating in the early part and deals with the common characteristics and general application guidelines for Copeland Scroll compressors in the later sections. Operating principles of the scroll compressor are described in Figure 15 at the end of this bulletin.As the drive for energy efficiency intensifies, water heating by fossil-fueled boilers and electric elements is being displaced by vapour compression heat pumps. Emerson Climate Technologies has developed two lines of special water heater compressors to meet the requirements of this demanding application. ZW**KA compressors are designed for lighter duty applications where the ambient temperature does not fall below 0°C and where lower water temperatures can be accepted as the ambient temperature falls. ZW**KS compressors are equipped with a vapour injection cycle which allows reliable operation in cold climates with significantly enhanced heating capacity, higher efficiency, and minimal requirement to reduce water outlet temperatures. Figure 1gives a brief product overview.Water heating is characterized by long operating hours at both high load and high compression ratios. Demand for hot water is at its highest when ambients are low and when conventional heat pump capacity falls off. On the positive side, the system refrigerant charge is usually small, so the risk to the compressor from dilution and flooded starts will usually be lower than in split type air-to-air heat pumps.Water heaters must operate in a wide range of ambient temperatures, and many systems will require some method of defrost. Some systems such as Direct Heating, Top Down Heating or Single Pass Heating operate at a constant water outlet temperature with variable water flow. Others such as Recirculation Heating, Cyclic Heating or Multipass Heating use constant water flow with the water outlet and inlet temperatures both rising slowly as the storage tank heats up. Both system types need to cope with reheating a tank where the hot water has been partially used, and reheating to the setpoint temperature is required. More complex systems deliver water at relatively low temperatures for under-floor heating circuits and are switched over to sanitary water heating a few times per day to provide higher temperature water for sanitary use. In addition, some countries have specific water temperature requirements for legionella control.ZW**KA ApplicationThe application envelopes for ZW**KA compressors are shown in Figures 2 - 4.Appropriate system hardware and control logic must be employed to ensure that the compressor is always operating within the envelope. Small short-term excursions outside the envelope are acceptable at the time of defrost when the load on the compressor is low. Operation with suction superheat of 5 -10K is generally acceptable except at an evaporating tem-perature above 100C when a minimum superheat of 10K is required.ZW**KS ApplicationThe ZW**KS* vapour-injected scroll compressors differ from ZW**KA models in many important details:• Addition of vapour injection• Significantly different application envelopes• Some differences in locked rotor amps (LRA), maximum continuous current (MCC), andmaximum operating current (MOC) – seenameplatesThe application envelopes for ZW**KS compressors are shown in Figures 5 and 6.Vapour Injection – Theory of Operation Operation with vapour injection increases the capacity of the outdoor coil and in turn the capacity and efficiency of the system – especially in low ambient temperatures. A typical schematic is shown in Figure 7. A heat exchanger is added to the liquid line and is used to cool the liquid being delivered to the heating expansion device. Part of the liquid refrigerant flow is flashed through an expansion valve on the evaporator side of the heat exchanger at an intermediate pressure and used to subcool the main flow of liquid to the main expansion device. Vapour from the liquid evaporating at intermediate pressure is fed to the vapour injection port on the ZW**KS compressor. This refrigerant is injected into the mid-compression cycle of the scroll compressor and compressed to discharge pressure. Heating capacity is increased, because low temperature liquid with lower specific enthalpy supplied to the outdoor coil increases the amount of heat that can be absorbed from the ambient air. Increased heat absorbed from the ambient increases the system condensing temperature and in turn the compressor power input. The increase in power inputalso contributes to the improvement in the overall heating capacity.Vapour Injection can be turned on and off by the addition of an optional solenoid valve on the vapour injection line on systems using a thermostatic expansion valve. Alternatively, an electronic expansion valve can be used to turn vapour injection on and off and to control the vapour injection superheat. A capillary tube is not suitable for controlling vapour injection.The major advantage of the electronic expansion valve is that it can be used to optimise the performance of the system and at the same time control the discharge temperature by injecting “wet vapour” at extreme operating conditions.The configurations and schematics shown are for reference only and are not applicable to every system. Please consult with your Emerson Application Engineer.Heat Exchanger and Expansion Device Sizing Various heat exchanger designs have been used successfully as subcoolers. In general they should be sized so that the liquid outlet temperature is less than 5K above the saturated injection temperature at the customer low temperature rating point. At very high ambient temperatures, it will normally be beneficial to turn vapour injection off to limit the load on the compressor motor. Application Engineering Bulletin AE4-1327 and Emerson Climate Technologies Product Selection Software can be used to help size the subcooling heat exchanger and thermal expansion valves, but selection and proper operation must be checked during development testing. Plate type subcoolers must be installed vertically with the injection expansion device connected at the bottom through a straight tube at least 150mm long to ensure good liquid distribution. See the schematic in Figure 8. Flash Tank ApplicationA possible flash tank configuration is shown in Figure9. This particular configuration is arranged to have flow through the flash tank and expansion devices in heating, and it bypasses the tank in defrost mode. The flash tank system works by taking liquid from the condenser and metering it into a vessel through a high-to-medium pressure expansion device. Part of the liquid boils off and is directed to the compressor vapour injection port. This refrigerant is injected into the mid-compression cycle of the scroll compressor and compressed to discharge pressure. The remaining liquid is cooled, exits from the bottom of the tank at intermediate pressure, and flows to the medium-to-low pressure expansion device which feeds the outdoor coil. Low temperature liquid with lower specific enthalpy increases the capacity of the evaporator without increasing mass flow and system pressure drops.Recommended tank sizing for single compressor application in this size range is a minimum of 200 mm high by 75 mm in diameter with 3/8 in. (9.5mm) tubing connections, although it is possible to use a larger tank to combine the liquid/vapour separation and receiver functions in one vessel. A sight tube (liquid level gauge) should be added to the tank for observation of liquid levels during lab testing. See schematic diagram Figure 10 for clarification.It is important to maintain a visible liquid refrigerant level in the tank under all operating conditions. Ideally the liquid level should be maintained in the 1/3 to 2/3 full range.Under no circumstances should the level drop to empty or rise to a full tank. As the tank level rises, liquid droplets tend to be swept into the vapour line leading to “wet” vapour injection. Although this can be useful for cooling a hot compressor, the liquid quantity cannot be easily controlled. Compressor damage is possible if the tank overflows. If liquid injection is required for any reason, it can be arranged as shown in Figures 7 and 9.Since liquid leaves the tank in a saturated state, any pressure drop or temperature rise in the line to the medium-to-low pressure expansion device will lead to bubble formation. Design or selection of the medium-to-low pressure expansion device requires careful attention due to the possible presence of bubbles at the inlet and the low pressure difference available to drive the liquid into the evaporator. An electronic expansion valve is the preferred choice. Intermediate Pressure and Vapour Injection SuperheatPressure in the flash tank cannot be set and is a complex function of the compressor inlet condition and liquid condition at the inlet of the high-to-medium pressure expansion device. However, liquid level can be adjusted, which in turn will vary the amount of liquid subcooling in the condenser (water to refrigerant heat exchanger) and vary the injection pressure. Systems with low condenser subcooling will derive the biggest gains by the addition of vapour injection. Systems operating with high pressure ratios will show the largest gains when vapour injection is applied. Such systems will have higher vapour pressure and higher injectionmass flow. Intermediate pressures in flash tank and heat exchanger systems should be very similar unless the subcooling heat exchanger is undersized and there is a large temperature difference between the evaporator and the liquid sides. Vapour exiting a flash tank will be saturated and may pick up 1 - 2K superheat in the vapour line to the compressor. Vapour injection superheat cannot be adjusted on flash tank systems. Heat exchanger systems will be at their most efficient when the vapour injection superheat is maintained at approximately 5K.APPLICATION CONSIDERATIONSHigh Pressure Cut OutIf a high pressure control is used with these compressors, the recommended maximum cut out settings are listed in Figure 1. The high pressure control should have a manual reset feature for the highest level of system protection. It is not recommended to use the compressor to test the high pressure switch function during the assembly line test.Although R-407C runs with higher discharge pressure than R-22, a common setting can be used. The cutout settings for R-134a are much lower, and the switches must be selected or adjusted accordingly.Low Pressure Cut OutA low pressure cut out is an effective protection against loss of charge or partial blockage in the system. The cut out should not be set more than 3 - 5K equivalent suction pressure below the lowest operating point in the application envelope. Nuisance trips during defrost can be avoided by ignoring the switch until defrost is finished or by locating it in the line between the evaporator outlet and the reversing valve. This line will be at discharge pressure during defrost. Recommended settings are given in Figure 1. Discharge Temperature ProtectionAlthough ZW compressors have an internal bi-metal Therm-O-Disc®(TOD) on the muffler plate, external discharge temperature protection is recommended for a higher level of protection and to enable monitoring and control of vapour injection on ZW**KS* models. The protection system should shut down the compressor when the discharge line temperature reaches 125°C. In low ambient operation, the temperature difference between the scroll center and the discharge line is significantly increased, so protection at a lower discharge temperature, e.g. 120°C when the ambient is below 0°C, will enhance system safety. For the highest level of system protection, the discharge temperature control should have a manual reset feature. The discharge sensor needs to be well insulated to ensure that the line temperature is accurately read. The insulation material must not deteriorate over the expected life of the unit.Discharge Temperature ControlSome systems use an electronic expansion valve to control the vapour injection superheat and a thermistor to monitor the discharge temperature. This combination allows the system designer to inject a small quantity of liquid to keep the discharge temperature within safe limits and avoid an unnecessary trip. Liquid injection should begin at approximately 115°C and should be discontinued when the temperature falls to 105°C. Correct functioning of this system should be verified during system development. It is far preferable to use liquid injection into the vapour injection port to keep the compressor cool rather than inject liquid into the compressor suction which runs the risk of diluting the oil and washing the oil from the moving parts. If some operation mode requires liquid injection but without the added capacity associated with “wet” vapour injection, a liquid injection bypass circuit can be arranged as shown in Figures 7 and 9.Caution: Although the discharge and oil temperature are within acceptable limits, the suction and discharge pressures cannot be ignored and must also fall within the approved application envelope.Discharge MufflersDischarge mufflers are not normally required in water heaters since the refrigerant does not circulate within the occupied space.Oil Dilution and Compressor CoolingThe oil temperature diagram shown in Figure 11is commonly used to make a judgment about acceptable levels of floodback in heat pump operation. Systems operating with oil temperatures near the lower limit line are never at their most efficient. Low ambient heating capacity and efficiency will both be higher if floodback is eliminated and the system runs with 1 - 5K suction superheat. Discharge temperature can be controlled by vapour injection, “wet” vapour injection, or even liquid injection if necessary. In this situation, the oil temperature will rise well into the safe zone, and the compressor will not be at risk of failure from diluted oil. The oil circulation rate will also be reduced as crankcase foaming disappears. Special care needs to be taken at the end of defrost to ensure that the compressor oil is not unacceptably diluted. The system will resume heating very quickly and bearing loads willincrease accordingly, so proper lubrication must be ensured.Electrical ConsiderationsMotor configuration and protection are similar to those of standard Copeland Scroll compressors. In some cases, a larger motor is required in the ZW**KS* models to handle the load imposed by operating with vapour injection. Wiring and fuse sizes should be reviewed accordingly.Brazing the Vapour Injection LineThe vapour injection connection is made from copper coated steel, and the techniques used for brazing the suction and discharge fittings apply to this fitting also. Low Ambient Cut-OutA low ambient cut-out is not required to limit heat pump operation with ZW**KS compressors. Water heaters using ZW**KA compressors must not be allowed to run in low ambients since this configuration would run outside of the approved operating envelope causing overheating or excessive wear. A low ambient cut-out should be set at 0°C for ZW**KA modelsIn common with many Copeland Scroll compressors, ZW models include the features described below: Internal Pressure Relief (IPR) ValveAll ZW compressors contain an internal pressure relief valve that is located between the high side and the low side of the compressor. It is designed to open when the discharge-to-suction differential pressure exceeds 26 - 32 bar. When the valve opens, hot discharge gas is routed back into the area of the motor protector to cause a trip.Internal Temperature ProtectionThe Therm-O-Disc® or TOD is a temperature-sensitive snap disc device located on the muffler plate between the high and low pressure sides of the compressor. It is designed to open and route excessively hot discharge gas back to the motor protector. During a situation such as loss of charge, the compressor will be protected for some time while it trips the protector. However, as refrigerant leaks out, the mass flow and the amperage draw are reduced and the scrolls will start to overheat.A low pressure control is recommended for loss of charge protection in heat pumps for the highest level of system protection. A cut out setting no lower than 2.5 bar for ZW**KA* models and 0.5 bar for ZW**KS* models is recommended. The low pressure cut-out, if installed in the suction line to the compressor, can provide additional protection against an expansion device failed in the closed position, a closed liquid line or suction line service valve, or a blocked liquid line screen, filter, orifice, or TXV. All of these can starve the compressor for refrigerant and result in compressor failure. The low pressure cut-out should have a manual reset feature for the highest level of system protection. If a compressor is allowed to cycle after a fault is detected, there is a high probability that the compressor will be damaged and the system contaminated with debris from the failed compressor and decomposed oil.If current monitoring to the compressor is available, the system controller can take advantage of the compressor TOD and internal protector operation. The controller can lock out the compressor if current draw is not coincident with the contactor energizing, implying that the compressor has shut off on its internal protector. This will prevent unnecessary compressor cycling on a fault condition until corrective action can be taken.Quiet Shut downAll scrolls in this size range have a fast acting valve in the center of the fixed scroll which provides a very quiet shutdown solution. Pressure will equalize internally very rapidly and a time delay is not required for any of the ZW compressors to restart. Also refer to the section on “Brief Power Interruption”. Discharge Check ValveA low mass, disc-type check valve in the discharge fitting of the compressor prevents the high side, high pressure discharge gas from flowing rapidly back through the compressor. This check valve was not designed to be used with recycling pump down because it is not entirely leak-proof.Motor ProtectorConventional internal line break motor protection is provided. The protector opens the common connection of a single-phase motor and the center of the Y connection on three-phase motors. The three-phase protector provides primary single-phase protection. Both types of protectors react to current and motor winding temperature.AccumulatorsThe use of accumulators is very dependent on the application. The scroll’s inherent ability to handle liquid refrigerant during occasional operating flood back situations often makes the use of an accumulator unnecessary in many designs. If flood back is excessive, it can dilute the oil to such an extent thatbearings are inadequately lubricated, and wear will occur. In such a case, an accumulator must be used to reduce flood back to a safe level that the compressor can handle.In water heaters, floodback is likely to occur when the outdoor coil frosts. The defrost test must be done at an outdoor ambient temperature of around 0°C in a high humidity environment. Liquid floodback must be monitored during reversing valve operation, especially when coming out of defrost. Excessive floodback occurs when the sump temperature drops below the safe operation line shown in Figure 11 for more than 10 seconds.If an accumulator is required, the oil return orifice should be 1 - 1.5mm in diameter depending on compressor size and compressor flood back results. Final oil return hole size should be determined through testing. ScreensScreens with a mesh size finer than 30 x 30 (0.6mm openings) should not be used anywhere in the system with these compressors. Field experience has shown that finer mesh screens used to protect thermal expansion valves, capillary tubes, or accumulators can become temporarily or permanently plugged with normal system debris and block the flow of either oil or refrigerant to the compressor. Such blockage can result in compressor failure.Crankcase Heater - Single PhaseCrankcase heaters are not required on single phase compressors when the system charge is not over 120% of the limit shown in Figure 1. A crankcase heater is required for systems containing more than 120% of the compressor refrigerant charge limit listed in Figure 1. This includes long line length systems where the extra charge will increase the standard factory charge above the 120% limit.Experience has shown that compressors may fill with liquid refrigerant under certain circumstances and system configurations, notably after longer off cycles when the compressor has cooled. This may cause excessive start-up clearing noise, or the compressor may lock up and trip on the protector several times before starting. The addition of a crankcase heater will reduce customer noise and light dimming complaints since the compressor will no longer have to clear out liquid during startup. Figure 12lists the crankcase heaters recommended for the various models and voltages.Crankcase Heat – Three-PhaseA crankcase heater is required for three-phase compressors when the system charge exceeds the compressor charge limit listed in Figure 1and an accumulator cannot be piped to provide free liquid drainage during the off cycle.Pump Down CycleA pump down cycle for control of refrigerant migration is not recommended for scroll compressors of this size. If a pump down cycle is used, a separate external check valve must be added.The scroll discharge check valve is designed to stop extended reverse rotation and prevent high-pressure gas from leaking rapidly into the low side after shut off. The check valve will in some cases leak more than reciprocating compressor discharge reeds, normally used with pump down, causing the scroll compressor to cycle more frequently. Repeated short-cycling of this nature can result in a low oil situation and consequent damage to the compressor. The low-pressure control differential has to be reviewed since a relatively large volume of gas will re-expand from the high side of the compressor into the low side on shut down. Minimum Run TimeThere is no set answer to how often scroll compressors can be started and stopped in an hour, since it is highly dependent on system configuration. Other than the considerations in the section on Brief Power Interruptions, there is no minimum off time. This is because scroll compressors start unloaded, even if the system has unbalanced pressures. The most critical consideration is the minimum run time required to return oil to the compressor after startup.Since water heaters are generally of compact construction, oil return and short cycling issues are rare. Oil return should not be a problem unless the accumulator oil hole is blocked.Reversing ValvesSince Copeland Scroll compressors have very high volumetric efficiency, their displacements are lower than those of comparable capacity reciprocating compressors. As a result, Emerson recommends that the capacity rating on reversing valves be no more than 2 times the nominal capacity of the compressor with which it will be used in order to ensure proper operation of the reversing valve under all operating conditions.The reversing valve solenoid should be wired so that the valve does not reverse when the system isshut off by the operating thermostat in the heating or cooling mode. If the valve is allowed to reverse at system shutoff, suction and discharge pressures are reversed to the compressor. This results in pressures equalizing through the compressor which can cause the compressor to slowly rotate until the pressures equalize. This condition does not affect compressor durability but can cause unexpected sound after the compressor is turned off.Oil TypeThe ZW**K* compressors are originally charged with mineral oil. A standard 3GS oil may be used if the addition of oil in the field is required. See the compressor nameplate for original oil charge. A complete recharge should be ~100 ml less than the nameplate value.ZW**K*E are charged with POE oil. Copeland 3MAF or Ultra 22 CC should be used if additional oil is needed in the field. Mobil Arctic EAL22CC, Emkarate RL22, Emkarate 32CF and Emkarate 3MAF are acceptable alternatives. POE oil is highly hygroscopic, and the oil should not be exposed to the atmosphere except for the very short period required to make the brazing connections to the compressor.System Noise and VibrationCopeland Scroll compressors inherently have low sound and vibration characteristics, but the characteristics differ in some respects from those of reciprocating or rotary compressors. The scroll compressor makes both a rocking and a torsional motion, and enough flexibility must be provided to prevent vibration transmission into any lines attached to the unit. This is usually achieved by having tubing runs at least 30cm long parallel to the compressor crankshaft and close to the shell. ZW compressors are delivered with rubber grommets to reduce vibration transmission to the system baseplate.Single Phase Starting CharacteristicsStart assist devices are usually not required, even if a system utilizes non-bleed expansion valves. Due to the inherent design of the Copeland Scroll, the internal compression components always start unloaded even if system pressures are not balanced. In addition, since internal compressor pressures are always balanced at startup, low voltage starting characteristics are excellent for Copeland Scroll compressors. Starting current on any compressor may result in a significant “sag” in voltage where a poor power supply is encountered. The low starting voltage reduces the starting torque of the compressor and subsequently increases the start time. This could cause light dimming or a buzzing noise where wire is pulled through conduit. If required, a start capacitor and potential relay can be added to the electrical circuit. This will substantially reduce start time and consequently the magnitude and duration of both light dimming and conduit buzzing.PTC Start ComponentsFor less severe voltage drops or as a start boost, solid state Positive Temperature Coefficient devices rated from 10 to 25 ohms may be used to facilitate starting for any of these compressors.Electrical ConnectionThe orientation of the electrical connections on the Copeland Scroll compressors is shown in Figure 13 and is also shown on the wiring diagram on the top of the terminal box cover.Deep Vacuum OperationScrolls incorporate internal low vacuum protection and will stop pumping (unload) when the pressure ratio exceeds approximately 10:1. There is an audible increase in sound when the scrolls start unloading. This feature does not prevent overheating and destruction of the scrolls, but it does protect the power terminals from internal arcing.Copeland Scroll compressors(as with any refrigerant compressor) should never be used to evacuate a refrigeration or air conditioning system. The scroll compressor can be used to pump down refrigerant in a unit as long as the pressures remain within the operating envelope. Prolonged operation at low suction pressures will result in overheating of the scrolls and permanent damage to the scroll tips, drive bearings and internal seal. (See AE24-1105 for proper system evacuation procedures.)Shell TemperatureCertain types of system failures, such as condenser or evaporator blockage or loss of charge, may cause the top shell and discharge line to briefly but repeatedly reach temperatures above 175ºC as the compressor cycles on its internal protection devices. Care must be taken to ensure that wiring or other materials, which could be damaged by these temperatures, do not come in contact with these potentially hot areas. Suction and Discharge FittingsCopeland Scroll compressors have copper plated steel suction and discharge fittings. These fittings are far more rugged and less prone to leaks than。
谷轮压缩机出现异响故障排除小窍门
据谷轮114压缩机制冷资讯网()谷轮压缩机事业部总结。
美国艾默生旗下的制冷压缩机出现异常响声的几种情况和解决方法简单介绍如下,供大家参考:(一)压缩机有不正常的响声原因一:气缸内有响声①气缸内掉入异物或破碎阀片,清除异物或破碎阀片;②活塞顶部与气缸盖发生顶碰,应调整间隙;③连杆大头瓦、小头衬套及活塞横孔磨损过度,应更换之;④活塞环过分磨损,工作时在环槽内发生冲击,更换活塞环;;⑤气缸内有水。
原因二:阀内有响声①进,排气阀组未压紧,应拧紧阀室方盖紧固螺母:;②阀片弹簧损坏,及时更换;③气阀结合螺栓、螺母松动,拧紧螺母;④阀片与阀盖之间间隙过大,调整间隙,必要时更换阀片原因三:曲轴箱内有响声①连杆瓦磨损过度,换新瓦,②连杆螺栓未拧紧,紧固之;③飞轮未装紧或键配合过松,应装紧,④主轴承损坏,更换轴承;⑤曲轴上之挡油圈松脱,换新挡油圈。
(二) 润滑系统的故障1、击油针折断,应更换;2、油位过高或过低,调整油位至规定范围3、油牌号不对,应按说明书要求换油:4、润滑油太脏,应换洁净的润滑油。
(三)、各级压力不正常(偏低或偏高)1、进、排气阀的阀片或弹簧损坏,漏气,应更换;2、进、排气阀的阀座上夹有脏物,漏气,清除脏物;3、空气滤清器堵塞严重,应清洗;4、气管路有漏气或冷却器漏气,修理之;5、活塞环,气缸磨损严重,漏气,应更换。
(四) 排气温度或冷却水排水温度过高(指水冷式)1、气缸拉毛使气缸过热,修理气缸,活塞;2、排气阀漏气或阀弹簧,阀片损坏、更换损坏零件;3、冷却水量不足,加大冷却水流量;4、冷却水路堵塞,气缸、气缸盖,冷却器内积垢过厚或堵塞,清除水垢或堵塞物;5、进、排气阀结炭,使气体通道不畅,清理结炭。
(五)排气压力表跳动1、进、排气阀片或弹簧滞住,检修;2、压力表损坏,更换之;3、仪表管路有异物。
清理吹除。
(六)排气量减小1、气阀漏气,研磨修理或更换新件;2、活塞环、刮油环、气缸磨损过度,更换磨损件;3、空气滤清器堵塞,气管路漏气,清除滤网下粉尘,修理管路;4、活塞上止点间隙过大,减少气缸垫、降低余隙容积,5、空压机转速过低于额定转速,检查线路电压、频率检修或更换电机。
压缩机的常见故障及维修
压缩机的常见故障及维修
1. 噪音过大:压缩机在工作时会发出一定的噪音,但如果噪音过大,可能是由于压缩机内部零件磨损或松动所致。
此时需要对压缩机进行拆卸检查,更换磨损严重的零件或紧固松动的零件。
2. 压力不足:如果压缩机的排气压力不足,可能是由于压缩机内部密封不良或气阀损坏所致。
此时需要对压缩机进行拆卸检查,更换密封件或气阀。
3. 温度过高:如果压缩机的温度过高,可能是由于压缩机内部润滑不良或冷却系统故障所致。
此时需要对压缩机进行拆卸检查,更换润滑油或修复冷却系统。
4. 漏电:如果压缩机出现漏电现象,可能是由于绝缘材料老化或电线接触不良所致。
此时需要对压缩机进行绝缘测试,更换老化的绝缘材料或修复电线接触不良的部分。
5. 压缩机不工作:如果压缩机完全不工作,可能是由于电源故障、控制系统故障或压缩机本身故障所致。
此时需要检查电源和控制系统,如有必要,对压缩机进行拆卸检查。
需要注意的是,压缩机的维修需要由专业技术人员进行,在维修过程中需要遵守相关安全规定,以确保维修工作的安全和有效。
同时,定期对压缩机进行维护保养,可以有效延长其使用寿命,减少故障的发生。
空调压缩机故障原因及预防措施
空調壓縮機故障原因及預防措施一、电源接线错误1、对于三相涡旋压缩机来讲,只能在一个方向上旋转。
发生反转时,会造成机械部件的异常磨损,并有可能引起PPS树脂密封圈的融化。
所以一定要按照铭牌上的指示方向连接U-V-W三相,防止压缩机反转。
预防措施:使用逆相保护器可以防止由于外接电源反相引起的三相压缩机反转。
但需要说明的是,它不能防止由于空调器内部接线错误引起的反转。
2.单相压缩机只有一种正确的接线方式-S-T,而其他五种接线方式是错误的。
在接线错误的条件下,热保护器即使动作,仍然可能会有电流通过线圈。
所以若操作不当,接线错误可能会导致压缩机电机损坏。
二、制冷剂泄漏空调系统发生制冷剂泄漏后,会导致制冷机流量减少,压力降低。
如此长期运转,一方面致使电机产生的热量无法被冷媒带出;另一方面由于过热度大,吸气温度上升,排气温度也随之升高。
这时电机温度也会升高造成IP频繁动作,一致于保护失效,电机烧毁。
排气温度过高会使R22开始热分解,生成酸与水。
还会使冷冻油中的碳游离出来,生成积碳。
预防措施:①防止空调系统焊接不良造成中缺氟或者充氟不足。
②安装不良,喇叭口接头处泄漏。
三、压缩机回液/液击:1.开机发生起泡:制冷剂通常在系统中温度最低的部分聚集、冷凝,在系统长时间停机时(如停止一个晚上),制冷剂循环中压缩机有可能成为温度最低的部分,导致许多液态制冷剂积存于压缩机中。
然后,在启动时,由于压力突然降低,液体制冷剂的迅速气化会产生大量泡沫,泡状的冷冻机油和液态制冷剂被吸入压缩机室内造成液体压缩,这时压缩机就伴有异常声音和剧烈的振动,并有可能发生损坏。
预防措施:为防止这种现象,定量加氟防止冷媒过多;对于长期放置和环境温度较低的情况下,机组开机前6小时对曲轴箱加热器通电预热。
2.充注位置不正确导致开机液击:在系统装机及维修时,从高、低压两侧对系统回路内部进行抽真空,然后从规定的充入口充入制冷剂。
液态制冷剂应从冷凝器出口充入,如果从压缩机吸气口充入,必须以气态充入;制冷剂充入时应严守规定的充入量,充入量过多,会造成油的稀释、润滑不足等问题,从而造成压缩机故障。
涡旋式压缩机简介及压缩机常见故障暖通吧分享
电源缺相和电压异常
电源电压变化范围不能超过额定电压的±10%三相间的电压不平衡不能超过3%如果发生缺相时压缩机正在运转它将继续运行但会有大的负载电流电机绕组会很快过热正常情况下压缩机会被热保护当电机绕组冷却至设定温度接触器会闭合但压缩机启动不起来出现堵转并进入堵转-热保护-堵转死循环 如果缺相发生压缩机启动时压缩机将启动不起来出现堵转进入堵转-热保护-堵转死循环 电压不平衡百分数计算方法为相电压与三相电压平均值的最大偏差值与三相电压平均值比值. 作为电压不平衡的结果在正常运行时负载电流的不平衡是电压不平衡百分点数的4-10倍
空调压缩机国内主要生产企业
优点: 结构简单、体积小、重量轻与活塞压缩机比:零件减少90%、体积减小40%、重量减轻15% 无吸排气阀减少了易损件降低吸排气阻力损失降低噪音与振动易于实现变转速 无余隙容积容积效率提高 不直接接触采用油膜密封摩擦损失小机械效率高 多压缩室同时工作工作连续压缩力矩变化平稳 缺点: 精度要求高形位公差都在微米级 无排气阀变工况性能欠佳 工作腔不易实施外部冷却压缩过程的热量难排出因此只能够压缩绝热指数小的气体或者内冷却 大排量涡旋压缩机难实现受齿高限制排量大直径大不平衡旋转质量增大机器不紧凑且重量增加
高压腔与低压腔涡旋压缩机特点
高压腔涡旋 压缩机结构
排气口
吸气口
定盘
动盘
机架
曲轴
电机定、转子
壳体
防自转滑环
主轴承
内置式过流、过热保护器
压差供油
低压腔涡旋压缩机结构
排气口
吸气口
定盘
动盘
机架
曲轴
电机定、转子
壳体
防自转滑环
主轴承
离心供油
壳体内高低压分隔板
高压腔结构
涡旋压缩机常见故障与原因分析
涡旋压缩机常见故障与原因分析1、压缩机常见故障—带液启动带液启动是停机状态时易出现的问题。
在停机状态时,制冷剂会从系统中迁移回压缩机内部并沉积在润滑油中。
危害:•制冷剂反复迁移会“洗”掉机械部件表面的油膜;•压缩机带液启动时,由于制冷剂蒸发会使润滑油泡沫化,影响轴承润滑等。
2、压缩机常见故障——回液过多制冷剂回液过多是运行状态易出现的问题。
是由于在压缩机运行状态时,反复过量的制冷剂液体迁移回压缩机而引起的结果。
危害:•制冷剂液体稀释润滑油,而导致轴承润滑不良。
任何系统都有回液过多的风险,回液过多可能由多种不同原因引起,例如:•蒸发器负荷过小(过多的回液往往在低负荷情况下发生)•换热器的换热效率差(蒸发器风扇故障 / 蒸发器中油太多,等)•化霜循环•膨胀阀选型过大•膨胀阀过热度控制不稳定•过热度设定偏低•……3、压缩机常见故障——回液液击是由于制冷剂液体,或者油,或者制冷剂和油的混合物,进入到涡旋压缩腔中而引起的结果。
压缩机液体产生的异常力会造成机械部件的损坏。
液击通常会出现在带液启动的条件下(制冷剂充过量,制冷剂大量迁移回压缩机)。
对于热泵系统,液击通常会出现在化霜循环中。
压缩机液体产生的异常作用力,会造成涡旋盘损坏(通常会损坏吸气侧的涡旋壁),以及十字滑环损坏。
液击引起机械部件损坏,所产生的金属碎屑进入到电机内部,通常也会造成电机绕组短路烧毁。
4、压缩机常见故障——失油/缺油失油会导致压缩机油池中的油量不足,而无法保证轴承及其它机械部件的润滑。
这种故障现象通常会发生在系统回油不良的情况下,会导致所有负载轴承面的严重磨损。
系统回油不良会由多种原因引起:•压缩机短循环;•管路设计原因导致油被滞留在系统中无法回到压缩机;•制冷剂泄漏;•长时间低负荷或部分负荷运行;•对于长管路系统(管长超过20米),没有适当的补油;•其它原因导致油被阻留在系统中,例如汽分的回油孔堵塞,或者过滤器堵塞,等等。
5、压缩机常见故障——排气温度高排气温度高是由于压缩机实际运行工况已超出压缩机安全运行曲线而引起的故障。
影响涡旋压缩机性能的因素分析
家用电器科技SCIENCE AND TECHNOLOGY OF HOUSEHOLD ELECTRICAPPLIANCE2000 No.9 P.71-73影响涡旋压缩机性能的因素分析廖全平1 前言涡旋压缩机因其效率高、振动噪音低、运转平稳、可靠性好等显著优点,正受到越来越多的空调生产厂家的青睐和认同。
对压缩机生产厂家来说,保证产品质量,生产出性能稳定、优质的压缩机是占领市场的先决条件。
本文结合涡旋压缩机生产实践,对影响涡旋压缩机性能的主要因素进行分析。
2 涡旋压缩机的功率和效率压缩机消耗的功率; 一部分是直接用于压缩气体的,为指示功率,另一部分用于克服机械摩擦,为摩擦功率。
两者之和称轴功率。
对于全封闭式涡旋压缩机,因其轴功率难于测量,常常在计算压缩机的能效比或COP值时,用的是电机输入功率,而把电机损失作为常数处理,而且把压缩机指示功率分为压缩内功和各种内部损失两部分。
内部损失则包括气体泄漏损失、加热损失、吸排气压力损失、流体阻力损失等。
如下所示:压缩机效率通常以能效比或COP值来衡量。
若实际吸气容积为VS(m3/min),折算到吸气状态的实际排气量为: V=n(Vs-vsmo)(1)式中:n--转速rev/min;vs--吸气比容(单位质量物质所占容积,m3/kg);mo--每分钟泄漏量kg/min。
假设ηv(容积效率)为0.9∽0.98。
估算:V=ηv·vs·n(2)∴ 实际制冷量Q=( V·qv·n)/(6.02×107)=(ηv ·vs·n2·qv)/ (6.02×107)(3)qo-单位制冷量当制冷或空调工质、工况确定后,Q只与ηv、vs及n有关。
COP=Q/N(w/w)(4)N--电机输入功率COP值与能效比(EER)的数值关系EER = 0.86 COP(5)3 因素分析从以上分析可知,影响涡旋压缩机性能的主要因素有:3.1 电机输入功率造成全封闭式涡旋压缩机电机输入功率偏大的原因,在压缩机实际工作过程中是非常复杂的,但主要有:电机损耗过大,包括铜损、铁损,这与电机材料和加工工艺有关(本文不作详细分析);压缩机工作过程引起的功率消耗。
涡旋压缩机故障分析
涡旋压缩机故障分析一、失效原因分析1)主要失效原因分布根据80/20法则,我们主要分析排气温度过高、缺油运行和真空运行三大失效问题进行分析。
(也有另外表达主要失效原因是:①带液启动;②回液过多;③液击;④失油/缺油;⑤排气温度高;⑥高压比;⑦电机烧毁(堵转、卡缸、电压、异物、接线等)等,但有些是包含和相互影响关系,上述三大失效原因基本包含)2)排气温度过高可能原因思维导图故障位置图示3)缺油运行可能原因思维导图◆容易导致:主轴偏心、定子扫膛、抱轴、卡缸、电机烧毁等◆加热带在第一次启动是应提前工作12小时以上,开机完成后不应长时间切断电源,否侧应重新预热;◆故障位置图示液击故障位置主要是涡旋盘吸气侧和十字滑环高压比:排气侧顶部与侧壁挤压,导致底部与顶部区域磨损或者涡旋盘崩裂4)真空运行思维导图注:压缩机接线柱通电状态下,会在真空或接近真空状态下,接线柱之间产生电弧击穿现象,导致接线柱烧坏,压缩机对地短路。
A故障位置图示带液启动和二、常见系统设计1.中高温系统2.低温喷液系统3.补气增焓系统4.设计组装应该注意点5.管路设计1)冷凝器高于压缩机时要增加防逆流弯和回油弯,蒸发器高于和低于压缩机时的管路设计6.真空运行——规避措施A.抽空:从高、低压侧同时抽真空,电磁阀打开,期间不能上电;B.注氟:高压侧注氟,开机前要往低压侧加氟;C.试运转:注氟量≥总充注量50%且高、低压侧都有压力故障图示1)水分超标:轻则镀铜、重则生锈,导致间隙变小、摩擦增大2)杂质超标:涡旋盘表面不规则磨损现象3)缺油/润滑不足:噪音、开机跳闸、异常磨损;4)电机损坏:开机跳闸、阻值异常、对地短路、过热烧毁5)十字滑环断裂:原因时启动压力不平衡,多发生于充完冷媒立即运转。
涡旋压缩机常见的损坏原因
涡旋压缩机常见的损坏原因涡旋压缩机常见的损坏原因主要有以下几点:1. 运行负荷过大:涡旋压缩机在长时间运行高负荷的情况下容易损坏。
如果工作负荷超过了涡旋压缩机的设计能力,就会导致设备过热、电机过载,甚至造成设备损坏。
2. 润滑不良:涡旋压缩机的润滑系统对设备的正常运行至关重要。
如果润滑油不足、质量不合格或者油路堵塞,会导致涡旋压缩机的摩擦增大、温升过高,从而加速设备的损坏。
3. 进气过滤不良:如果涡旋压缩机的进气过滤器没有定期清洗或更换,或者进气管道受到污染,就会导致灰尘、颗粒物等进入压缩机内部,造成设备受损。
4. 冷却不良:涡旋压缩机需要通过冷却系统来降低设备温度,保证正常的运行。
如果冷却系统故障、冷却水流量不足、冷却器堵塞等,就会导致设备温度升高,增加设备的损坏风险。
5. 漏气:涡旋压缩机的密封性能对设备运行起着关键的作用。
如果密封件老化、损坏或者安装不当,就会导致漏气情况的发生,从而降低了设备的效率,增加了设备的损坏风险。
6. 频繁启停:涡旋压缩机频繁启停会造成设备的损坏。
因为启动时的电流冲击会引起设备的振动和电气压力的变化,这些变化对设备的机械部件和电气元件都会产生不利影响,导致设备的损坏。
7. 过载工作:涡旋压缩机在长时间内过载工作会导致设备的损坏。
因为过载工作会导致设备的温度升高,电机的功率也会超过额定值,从而减少了设备的使用寿命。
8. 过热问题:涡旋压缩机在长时间运行中,由于工作原理特殊,容易发生过热问题。
如果设备的冷却系统不正常工作,或者冷却水温度过高,就会使得设备的温度升高,导致设备失效。
9. 维护不当:如果涡旋压缩机的日常维护不到位,如缺乏定期的润滑、检查和清洁,设备的零部件容易出现早期故障,最终导致设备的损坏。
10. 设备老化:涡旋压缩机作为一种机电设备,随着使用时间的增加,其各个零部件都会出现磨损和老化的现象,从而导致设备的损坏。
因此,定期对涡旋压缩机进行检修和更换老化零部件是保持设备正常运行的重要措施。
谷轮压缩机故障维修指南
缺油 - 轴承异常损耗 这是由于曲轴内没有足够的油来润滑承重轴 - 曲轴异常磨损 承表面。当系统中的回液不足时,所有承重的 - 曲轴内油位过低 轴承表面就会产生异常磨损。
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一般电气故障 - 整个绕组有均匀的过热现 有许多电机故障是由于机械和润滑产生问题 象或烧损 造成的, 另有许多故障是因为外部电气部件失 灵造成的。 单相烧损 三相电机的两相过热或烧损。 这是由于未烧 损相无电流通过而另两相过载。 一半绕组单相烧损 在有两个接触器的部分绕组起动系统中有部 分电机绕组出现缺相时会出现该情况。 一半绕组烧损 三相电机在两个接触其中的一半绕组过热或 烧损。
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1. 选用合适的压缩机 及保证蒸发器有足够 的热度 2. 纠正不正常的低负 荷工况 3. 如有必要,利用气 液分离器防止液体不 受控制地进入压缩机 4. 检查热力膨胀阀是 否选择过大 -涡旋盘磨损 -定子烧损产生斑点 1. 高压缩比:检查低 吸气压力和高排气压 力情况, 低负荷情况及 蒸发器是否有问题 2. 检查低压保护设置 3. 检查冷凝器是否 脏, 冷凝风机是否损坏 及周围环境温度 4. 检查流过压缩机的 气流是否充足
谷轮压缩机故障维修指南 大多数压缩机故障与系统问题有关,必须将系统问题排除以防故障再次发生。当压缩机发生故障后, 对其进行检查,可发现系统问题的症状,将其排除将有助于避免今后在发生故障。
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液击 - 阀片或曲轴损坏 这是由于在汽缸内压缩机液体时会产生液击。 - 排气阀片升程限制器固定 液体可以是制冷剂或油, 但更可能是两者的混 螺松动或损坏 合物。 停机时回气冷却型压缩机中的制冷剂迁 移和空气冷却型压缩机的回液都会造成液击。
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1.使用合适的电流接 触器替换
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1. 使用合适的电流接 触器替换 2. 关闭一个电流接触 器检查电流反馈 1. 检查 C, S, 和 R 的线圈 2. 关闭一个电流接触 器检查电流反馈 3. 检查压缩机的过载 -单相电机中仅运行绕组烧损 1. 检查继电器 2. 检查运行电容
压缩机常见三种详细故障分析报告
压缩机常见三种详细故障分析压缩机常见故障分析(1)——电机烧毁电动机压缩机〔以下简称压缩机〕的故障可分为电机故障和机械故障(包括曲轴,连杆,活塞,阀片,缸盖垫等)。
机械故障往往使电机超负荷运转甚至堵转,是电机损坏的主要原因之一。
电机的损坏主要表现为定子绕组绝缘层破坏〔短路〕和断路等。
定子绕组损坏后很难与时被发现,最终可能导致绕组烧毁。
绕组烧毁后,掩盖了一些导致烧毁的现象或直接原因,使得事后分析和原因调查比拟困难。
然而,电机的运转离不开正常的电源输入,合理的电机负荷,良好的散热和绕组漆包线绝缘层的保护。
从这几方面入手,不难发现绕组烧毁的原因不外乎如下六种:(1)异常负荷和堵转;(2)金属屑引起的绕组短路;(3)接触器问题;(4)电源缺相和电压异常;(5)冷却不足;(6)用压缩机抽真空。
实际上,多种因素共同促成的电机损坏更为常见。
1.异常负荷和堵转电机负荷包括压缩气体所需负荷以与克制机械摩擦所需负荷。
压比过大,或压差过大,会使压缩过程更为困难;而润滑失效引起的摩擦阻力增加,以与极端情况下的电机堵转,将大大增加电机负荷。
润滑失效,摩擦阻力增大,是负荷异常的首要原因。
回液稀释润滑油,润滑油过热,润滑油焦化变质,以与缺油等都会破坏正常润滑,导致润滑失效。
回液稀释润滑油,影响摩擦面正常油膜的形成,甚至冲刷掉原有油膜,增加摩擦和磨损。
压缩机过热会引起使润滑油高温变稀甚至焦化,影响正常油膜的形成。
系统回油不好,压缩机缺油,自然无法维持正常润滑。
曲轴高速旋转,连杆活塞等高速运动,没有油膜保护的摩擦面会迅速升温,局部高温使润滑油迅速蒸发或焦化,使该部位润滑更加困难,数秒钟内可引起局部严重磨损。
润滑失效,局部磨损,使曲轴转动需要更大力矩。
小功率压缩机〔如冰箱,家用空调压缩机〕由于电机扭矩小,润滑失效后常出现堵转〔电机无法转动〕现象,并进入“堵转-热保护-堵转〞死循环,电机烧毁只是时间问题。
而大功率半封闭压缩机电机扭矩很大,局部磨损不会引起堵转,电机功率会在一定X围内随负荷而增大,从而引起更为严重的磨损,甚至引起咬缸〔活塞卡在气缸内〕,连杆断裂等严重损坏。
压缩机常见故障及解决方法
压缩机常见故障及解决方法压缩机在使用过程中常出现的故障主要有以下几种,下面将逐一介绍这些故障及解决方法。
1.温度过高压缩机温度过高是一种常见的故障,通常会导致机器发出异响或者无法正常工作。
温度过高的原因可能是由于过载或者缺乏润滑。
解决方法:a)检查负载是否过大,如果过大,需进行适当调整,以保证负载处于正常范围。
b)检查压缩机的润滑系统,确保润滑油的添加量充足,不过多或者过少。
c)清理冷却系统,检查冷却风扇是否运转正常,确保压缩机冷却效果良好。
2.压力不稳定压缩机在使用过程中可能出现压力不稳定的情况,可能会导致供气不稳或者气流量不足。
解决方法:a)检查供气系统中的管路,确保管路正常,没有堵塞或者泄漏。
b)调整压缩机的稳压系统,确保压力调节阀的动作准确,稳定输出压力。
c)检查压缩机的排气阀门,确保排气顺畅,不会出现堵塞。
3.压缩机漏气压缩机漏气问题可能会导致气源不稳定,气量不足。
解决方法:a)定期检查压缩机的密封件,确保密封件完好,没有损坏或者老化。
b)检查压缩机的排气管路,确保管路没有泄漏点。
c)检查压缩机的进气系统,确保进气过滤器没有堵塞或者泄漏。
4.压缩机振动过大当压缩机运行过程中出现振动过大的情况,可能会对机器造成损坏。
解决方法:a)检查压缩机的基础安装,确保机器的固定螺栓没有松动。
b)检查压缩机的旋转部件,确保旋转部件没有损坏或者松动。
c)进行动平衡处理,确保压缩机旋转平稳,减小振动。
5.压缩机启动困难有时候压缩机会出现启动困难的情况,不能正常启动。
解决方法:a)检查电源线路,确保电源供应稳定,电压正常。
b)检查压缩机的电机,确保电机正常运转,没有故障。
c)检查压缩机的控制系统,确保控制系统运作正常。
d)检查空气滤清器,确保滤清器没有堵塞,影响正常的空气流量。
总结:压缩机的常见故障有温度过高、压力不稳定、漏气、振动过大和启动困难等。
解决这些故障的方法包括调整负载、检查润滑系统、清理冷却系统、检查管路和排气阀门、检查密封件和进气系统、检查基础安装和旋转部件、进行动平衡处理,以及检查电源线路、电机、控制系统和空气滤清器。
压缩机常见故障及事故维修
压缩机常见故障及事故维修压缩机是用来提高气体压力和输送气体的机械。
从能量的观点来看,压缩机是属于将原动机的动力能转变为气体压力能的机器。
随着科学技术的发展,压力能的应用日益广泛,使得压缩机在国民经济建设的许多部门中成为必不可少的关键设备之一。
压缩机在运转过程中,难免会出现一些故障,甚至事故。
故障是指压缩机在运行中出现的不正常情况,一经排除压缩机就能恢复正常工作,而事故则是指出现了破坏情况。
两者往往是关联的,若碰到故障不及时排除便会造成重大事故。
一、常见故障及其原因和措施排气量不足:排气量不足是与压缩机的设计气量相比而言。
主要可从下述几方面考虑:1、进气滤清器的故障:积垢堵塞,使排气量减少;吸气管太长,管径太小,致使吸气阻力增大影响了气量,要定期清洗滤清器。
2、压缩机转速降低使排气量降低:空气压缩机使用不当,因空气压缩机的排气量是按一定的海拔高度、吸气温度、湿度设计的,当把它使用在超过上述标准的高原上时,吸气压力降低等,排气量必然降低。
3、气缸、活塞、活塞环磨损严重、超差、使有关间隙增大,泄漏量增大,影响到了排气量。
属于正常磨时,需及时更换易损件,如活塞环等。
属于安装不正确,间隙留得不合适时,应按图纸给予纠正,如无图纸时,可取经验资料,对于活塞与气缸之间沿圆周的间隙,如为铸铁活塞时,间隙值为气缸直径的0.06/100~0.09/100;对于铝合金活塞,间隙为气径直径的0.12/100~0.18/100;钢活塞可取铝合金活塞的较小值。
4、填料函不严产生漏气使气量降低。
其原因首先是填料函本身制造时不合要求;其次可能是由于在安装时,活塞杆与填料函中心对中不好,产生磨损、拉伤等造成漏气;一般在填料函处加注润滑油,它起润滑、密封、冷却作用。
5、压缩机吸、排气阀的故障对排气量的影响。
阀座与阀片间掉入金属碎片或其它杂物,关闭不严,形成漏气。
这不仅影响排气量,而且还影响间级压力和温度的变化;阀座与阀片接触不严形成漏气而影响了排气量,一个是制造质量问题,如阀片翘曲等,第二是由于阀座与阀片磨损严重而形成漏气。
谷轮压缩机现场检查注意事项及解剖分析
压缩机不启动
首先检查压缩机端子是否电压正常,不正常时为用户原因 如果电压正常,检查压缩机静态电阻
– –
静态电阻不平衡,说明电机绕组有可能短路 静态电阻开路时,如这时压缩机温度很高,很有可能为压缩 机本身内置保护,等一小时左右的时间冷却,如仍未好转, 压缩机电机已经受损
如果静态电阻正常,检查压缩机对地绝缘 如电机检查为正常,很有可能为运转部件如轴承等损坏 如果是单相, 还要检查电容及接线方式
压缩机现场检查与解剖分析
压缩机故障现象
压缩机不启动 压缩机噪音大 压缩机电流大 压缩机排气温度过高 压缩机无吸排气 压缩机吸气压力过低或过高 压缩机排气压力过高或过低 压缩机电流不平衡 压缩机绝缘不良
压缩机故障检测工具
手 – 对于无电气故障且正在运行的正常压缩机, 压缩机外壳从上 至下依次相对为 “顶盖: 烫”-“中部吸气: 凉”- “底部: 热” 眼 – 观察不正常的安装,维护或使用中的问题, 特别是压缩机已经 无法运行 万用表 – 测试压缩机供电,保护模块电压,压缩机电流,压缩机静态 电阻,绝缘电阻,传感器电阻,电容等 压力表 – 检测压缩机及系统的高低压力 温度计 – 准确测量压缩机的各点湿度, 以及系统部件如热力膨胀 阀的过热度, 同时可以压力表的读数是否准确
– 诊断不一定总是正确 • 浮动密封可能由于低质量流量而不能浮起来-吸气压力为零 – 此法不能检测压缩机功率是否正常或太高
切勿堵塞吸气口来看压缩机能否抽真空 用手堵住部分排气口看压缩机是否能泵气
绕组或电流不平衡
较小的不平衡是正常的
– 精确检测绕组阻值较困难
较大的电流不平衡是正常的-特别是在负载较低时 (A1 + A2 + A3)/3 = Aavg 平均电流 检测每相电流A1/Aavg, A3/Aavg, A3/Aavg与均值的差别,看是否超过+ /-15%. 3
谷轮涡旋压缩机应用指南
关于涡旋压缩机在 1 小时内究竟能启动和停机多少次还没有肯定的答复,因为它很大程 度上取决于系统配置。因为涡旋压缩机是在卸载条件下启动的,即使在不平衡压力下,所以 没有最短停机时间的规定。最关键的考虑是在启动后需要让油返回压缩机的最小运行时间。 由于这些压缩机装有玻璃视镜,所以很容易进行测试。最短的运行时间就是当压缩机启动时 失油至油返回压缩机油池至恢复视镜中正常油位时所需要的时间。如果将压缩机在比该时间 短的时间间隔进行循环停开,例如为了保持非常精确的温度控制,会造成逐渐失去润滑油以 致损坏压缩机。进一步关于防止压缩机频繁循环停开的资料可查阅应用工程手册 17-1262.
4-1316
ZR90K3~ZR19M3 和 ZR250KC~ZR300KC 谷轮涡旋压缩机应用指南
筑龙网
前言 本手册叙述 7.5~25HP R22 和 R407C 谷轮涡旋压缩机的运行特性,设计特点和应用要求。
典型机型是 ZR90K3-TWC, ZR16M3-TW7 和 ZR300KC-TWD。如 需 得 到 更 多 详 情 , 请 上 网 页 查询产品资料。谷轮涡旋压缩机的工作原理已在谷轮工程应用 手册 4-1312 中叙述了。以下叙述的压缩机运行特性和设计特点有一些是与小型的谷轮涡 旋压缩机不同的。
在接近 0.05MPa(表)(7psig)(-32℃/-25°F 饱和吸气温度)压力下运行明显地超出图 2 表 示的允许运行范围了。但是,由于环境温度低,热泵在某些地理位置必须运行在这些范围。 只要冷凝温度不超过 32℃(90°F)且排气温度不超过 135℃(275°F),这是允许的。在这些工 况下有些液体返回压缩机有助于保持排气温度在控制范围内。某些情况下甚至 0.05MPa (表)(7psig)低压控制器还会造成噪扰性跳闸。这可能在换向阀动作时发生的短暂性吸气阻塞 或在热泵启动时节流元件前没有足够的液体压力。因此,可以将低压控制器移至液管,在那 里不会发生会引起噪扰性跳闸的短暂性吸气压力下降。但是,必需增加一排气温度控制器。 另一种方法是将低压控制器仍放在吸气管路而给低压控制器 60 秒钟(最大)的低压延时时间。 让机组在 60 秒钟内不理采低压控制器的讯号而让压缩机继续运行。
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谷轮涡旋压缩机故障现象
谷轮涡旋压缩机主要故障
主要有以下四种:
①浮动密封圈损坏,高低压串气。
由涡旋压缩机的结构特点可知,为了在涡旋定子上部提供适当的气体压力,在涡旋定子上的适当的中间压缩处开了一个中间压力通道,以提供中间压力。
在中间压力腔上部设有浮动密封装置,因此涡旋顶部受排气压力与中间压力作用。
除了平衡涡旋内部压缩气体压力以外,还提供了顶端和底槽间的密封力,
该密封力靠浮动密封圈来实现。
该密封圈由一种类似于橡胶或塑料的非金属材
料制成。
故障现象一般表现为压缩机电机完好,并且能够通电运行,但机组的
排气压力不升高,吸气压力也不降低,吸气与排气几乎没有压差,排气管不热,吸气管也不凉。
压缩机电流与额定值差别很大,事实上压缩机在空转。
②涡旋盘损坏。
涡旋盘损坏除有上述浮动密封圈损坏的特征外,还能听到压缩机内部明显
的金属撞击声,这是涡旋盘被击碎后的金属碎片相互撞击或与压缩机壳体撞击
的声音。
③电机烧毁。
当接通电源时,熔断器熔断或短路器跳断,压缩机无法启动。
④电机抱轴,轴承损坏。
压缩机电源接通时,听到机壳内电动机有嗡嗡的声音,但不运转,并且电
流上升很快,几秒钟后,压缩机内部过载保护或外部热继电器保护动作,切断
电源。
有时保护器来不及动作,很快达到堵转电流,可能直接导致电机烧毁。
2故障原因分析及防治措施
2.1故障压缩机解剖后发现,密封圈发生了局部的融化或是断裂。
其原因是:由于制冷剂泄漏等原因,吸气压力降低(但是即使装了低压保护装置,也可能还没有达到保护设定值,而低压保护并没有切断),吸气过热度增大,致使排气温度迅速升高,这时,如果未装排气温度保护器,或是安装不当,会使系统存在严重的过热现象。
避免密封圈发生热损坏最有效的办法是正确安
装排气温度保护器。
排气温度保护器的温度设定一般为125一130℃;排气温
度保护器的感温包一般安装在压缩机排气管上,距离排气口不超过150 mm,感
温包与排气管固定要牢固,并且需要严格保温;排气温度保护器的接线可以和
压缩机的其他保护措施(如高压保护或低压保护)串联起来,共同形成对压缩机
的保护。
2.2涡旋盘损坏一般是由液击引起。
主要有三种情况:一是开机的瞬间有大量的制冷剂液体进人压缩机;二是
蒸发器水流量不够(蒸发负荷减小),压缩机有回液现象;三是机组热泵运行除
霜不好,大量液体制冷剂没有蒸发就进人压缩机,或是四通阀换向瞬间蒸发器(热泵运行时为冷凝器)内的液体进人压缩机。
解决液击或回液的问题,主要从
以下几方面考虑。
①管路设计上要避免开机时液态制冷剂进人压缩机,这可能需要对系统做
过量回液试验,尤其是充注量比较大的制冷系统。
在压缩机吸气口增加气液分
离器是解决这个问题的有效办法,尤其是在采用逆循环热气除霜的热泵机组中。
②开机前,对压缩机油池进行足够长时间预热可以有效避免大量制冷剂积
存于压缩机润滑油中。
对于防止液击也有一定作用。
③水系统流量保护不可缺少,这样当水流量不够时起到保护压缩机的作用,以免机组有回液现象或是严重时冻坏蒸发器。
流量开关损坏时要及时进行修理
或更换,切不可短接流量开关。
2.3电机绕组烧毁与电气设计的保护有关,或是由机组运行使用不当造成的。
①由于蒸发器冻裂,氟系与水系串通后,压缩机进水导致压缩机烧毁。
其
原因有:
a.由于各种原因〔水过滤器脏堵,水泵匹配不合理等),造成水系统流量小,而水流保护又失灵或短接,蒸发器冰冻后冻裂制冷剂铜管;
b.冬季机组水系统存水而又没有采取防冻措施,蒸发器冻裂。
②负荷异常.使压缩机内置热保护器频繁动作,有可能使其触点发生粘连而使保护器失去作用,从而烧毁电机。
润滑失效、摩擦阻力增大是负荷异常的主
要原因。
要解决润滑失效的问题,主要从以下几方面着手:防止回液、防止润
滑油过热(排气温度高)、解决系统回油或缺油问题。
③如果电气设计没有过载保护或过流保护,有可能产生以下危险:如果压
缩机电流较大,电机绕组持续在较高温度下工作,而这个温度又不足以使内置
热保护器动作,这种情况下有可能造成线圈绝缘层破坏而使电机短路烧毁。
增
加外部过载保护是防止电机烧毁的有效手段,如热继电器保护。
热继电器的设
定值应能在不超过压缩机额定电流的140%时断开。
另外机组电源线通过空气开
关也是非常重要的。
④系统内有杂质,杂质腐蚀和磨损压缩机电机线圈,导致电机烧毁。
⑤电机的频繁启停会使质量不好的接触器触点容易发生粘连,这样,依靠
接触器断开压缩机电源回路的所有保护控制(高低压保护、排气温度保护、水流保护等)将全部失效,压缩机处于无保护状态,从而导致电机烧毁。
因此,应正确选择接触器。
⑥冷却不足也是引起压缩机电机烧毁的原因之一。
全封涡旋压缩机一般是
靠制冷剂冷却的,制冷剂大量泄漏会造成对压缩机冷却的不够。
当然,制冷剂
大量泄漏一般会引起低压保护或热保护,但是如果低压保护和热保护失效,就
会导致压缩机的烧毁。
2.4电机抱轴,轴承损坏的根本原因是润滑问题。
又分以下几种情况:
①润滑油不够,或者系统回油有问题,在这种情况下,轴承得不到充分润滑,轴承磨损加剧,最终导致电机抱轴。
因此,一般要求冷冻油与制冷剂的质量比大于0.35,否则就要补充冷冻油。
另外,压缩机的现场替换也会造成冷冻油的流失或是变质,这时就需要补充部分冷冻油。
②系统内有杂质进人轴承,轴承磨损或卡死,导致电机抱轴。
根据有关研究人员的分析,杂质的主要成分是铜、铁、碳化物等,这主要是在生产过程中产生的,如钎焊时焊瘤或焊渣进人铜管;铜管切割时铜屑进人系统;压缩机运行过程中润滑不良会加大摩察引起的高温,而高温会导致润滑油或其他有机物的碳化;系统抽空不彻底,有水分存在,或者冷媒中水分控制不够纯,水分就会在系统中导致"镀铜"现,最终会使系统中产生粉末状的铜铁小颗粒;工作场地不清洁,灰尘、杂质进人系统。
针对这些问题,应该完善生产工艺,严格执行工艺纪律,提高工人的技术水平。
③开机前没有预热或预热时间不够,致使系统内大量的制冷剂迁移至压缩机,液态制冷剂在压缩机内积存较多,而液态制冷剂的密度比冷冻油要大,因此在压缩机底部积存的制冷剂分两层,上部是冷冻油(富油相),下部是制冷剂(富制冷剂相)。
下部的制冷剂阻止冷冻油进入轴承润滑处(相当于抬高了冷冻油液面),开机启动时进人轴承润滑面的几乎全是制冷剂,因而导致润滑不良,并且泡沫状的冷冻油和液态制冷剂进人压缩室还会造成液体压缩。
预防制冷剂迁移和在润滑油中溶解的一个有效措施是使用有加热器,通过对油的加热,使油的温度比系统其他部位温度高,润滑油中的制冷剂蒸发[51,但是油加热器的功率也不能太高,否则会使油过热,粘度降低,甚至碳化,也会引起轴承润滑不当。
因此,应正确选择油加热器。
另一个问题是,即使机组设计了加热器,但是在实际应用过程中,有的用户往往忽略这一点,造成开机前没有预热或预热时间不够的问题屡屡发生,因此,如果可能的话,建议在电气控制系统上加以设置,保证足够的预热时间。
预热时间一般为12--24 h时,使油温比环境温度高10-12℃。