螺杆式制冷压缩机的工作原理及结构

螺杆式制冷压缩机的工作原理及结构 螺杆式制冷压缩机的工作原理及结构 , 第一节 螺杆式制冷压缩机的工作原理 1、螺杆式制冷压缩机的特点 与活塞压缩机的往复容积式不同，螺杆式压缩机是一种回转容积式压缩机。与活塞压缩机相比，螺杆式制冷压缩机有以下优点: a.体积小重量轻，结构简单，零部件少，只相当于活塞压缩机的1/3,1/2; b.转速高，单机制冷量大; c.易损件少，使用维护方便; d.运转平稳，振动小; e.单级压比大，可以在较低蒸发温度下使用; f.排气温度低，可以在高压比下工作; g.对湿行程不敏感; h.制冷量可以在10%,100%之间无级调节; i.操作方便，便于实现自动控制; j.体积小，便于实现机组化。 缺点: 转子、机体等部件加工精度要求高，装配要求比较严格; 油路系统及辅助设备比较复杂;因为转速高，所以噪声比较大。 2、螺杆式制冷压缩机工作原理 双螺杆(压缩机)是由一对相互啮合、旋向相反的阴、阳转子，阴转子为凹型，阳转子为凸型。随着转子按照一定的传动比旋转，转子基元容积由于阴阳转子相继侵入而发生改变。侵入段(啮合线)向排气端推移，于是封闭在沟槽内的气体容积逐渐缩小，压力逐渐升高，压力升高到一areas of the introduction of social capital, improve urban management efficiency and effectiveness. Third, we must adhere to the "concerned about face saving" and "the importance of lining" combined. Premier Li Keqiang once pointed out: "the face is the style of the city, and the lining is the conscience of the city. In the improvement of the urban environment, not only to attention to face, we should pay more attention to the lining. To do a good job of environmental health, Jeeves, traffic order rectification, and built underground pipe network, combined underground road network, underground parking, enhancing the overall image of the city. Fourth, we must adhere to the combination of "scientific planning" and "fine management". City "building, seven in charge". To continue to improve the urban development planning and the overall layout, coordinate and promote the construction of the new, transformation of the old city, center city by the pull framework to improve the function, dominated by government oriented society, by laying a solid foundation to gather popularity change. At the same time, to adhere to excellence to grasp the management. The establishment of headquarters specifically a technical standards group, is responsible for this thing catch. Including street lighting design and plaque size, elevation brush what color should be careful planning, elaborate design, careful management. 定值(或者说转子旋转到一定位置)时，齿槽(密闭容积)与排气孔相 通，高压气体排出压缩机，进入油分离器。吸气、压缩、排气过程见示意图。 3、内压比与螺杆压缩机经济性的关系 螺杆压缩机是没有气阀的容积型回转式压缩机，吸、排气孔的打开和关闭完全为几何结构决定的，即吸气终了的体积和压缩结束时的体积是固定的，即内容积比是固定的。而活塞压缩机的吸、排气阀片的打开是由吸、排气腔的压力决定的。 内容积比:Vi=VS/Vd VS—吸气终了时的容积，Vd—压缩终了时的容积 内压力比:Za = Pd / P0 Pd—压缩终了压力，P0—吸入压力 可见，内压比是由内容积比决定的。所以，压缩终了压力Pd是由吸气压力和内容积比决定的。 外压力比:Zy = Py / P0 Py—排气背压力，或者说冷凝压力 外压比是由蒸发温度和冷凝温度决定的，即由运行工况所决定的。 当压缩机内压比小于外压比时(内容积比小)，压缩终了压力小于冷凝压力，气体进入排气口后不能排出压缩机，会受到下一个齿槽排出的气体继续压缩(等容压缩)，直到压力达到冷凝压力时，才会排出排气口，进入排气管路;当压缩机内压比大于外压比时(内容积比大)， 压缩终了压力大于冷凝压力，气体进入排气口后压力迅速降低至冷凝压力(等容膨胀)。不论是等容压缩还是等容膨胀，都会使压缩机功耗增加。 areas of the introduction of social capital, improve urban management efficiency and effectiveness. Third, we must adhere to the "concerned about face saving" and "the importance of lining" combined. Premier Li Keqiang once pointed out: "the face is the style of the city, and the lining is the conscience of the city. In the improvement of the urban environment, not only to attention to face, we should pay more attention to the lining. To do a good job of environmental health, Jeeves, traffic order rectification, and built underground pipe network, combined underground road network, underground parking, enhancing the overall image of the city. Fourth, we must adhere to the combination of "scientific planning" and "fine management". City "building, seven in charge". To continue to improve the urban development planning and the overall layout, coordinate and promote the construction of the new, transformation of the old city, center city by the pull framework to improve the function, dominated by government oriented society, by laying a solid foundation to gather popularity change. At the same time, to adhere to excellence to grasp the management. The establishment of headquarters specifically a technical standards group, is responsible for this thing catch. Including street lighting design and plaque size, elevation brush what color should be careful planning, elaborate design, careful management. 因为一台压缩机的内压比一般都是固定的，而工况的变化会导致内、外压比不一致。所以在选用压缩机时，应选用内压比与使用工况对应的外压比相同或接近的，才能获得节能。 常用的调节内压比的办法有: 更换具有不同开口位置的滑阀(滑阀上开有径向排气口)，通过改变排气口位置来改变内压比; 采用具有可以调节内容积比的压缩机(可调内容积比螺杆压缩机)。 第二节 螺杆式压缩机的结构 螺杆制冷压缩机一般可分为机体部件、转子部件、滑阀部件、轴封部件和联轴器部件。 1)机体部件 机体部件主要是由机体、吸气端座、吸气端盖 排气端座、排气端盖及轴封压盖等零件组成。 机体:机体内设有?字形空腔，容纳转子，是压缩机的工作汽缸。机体内腔上部设有径向吸气口。机体下部有一部分缸壁被镗掉用于放置滑阀。要使压缩机压缩气体的效率高，就要求机体孔与转子之间的间隙必须严格保证。滑阀端部与机体的配合要严密，组装时需经钳工研合。 吸气端座:吸气端座上部设有轴向吸气孔口，气体进入压缩机的通道。吸气端座有三个呈三 areas of the introduction of social capital, improve urban management efficiency and effectiveness. Third, we must adhere to the "concerned about face saving" and "the importance of lining" combined. Premier Li Keqiang once pointed out: "the face is the style of the city, and the lining is the conscience of the city. In the improvement of the urban environment, not only to attention to face, we should pay more attention to the lining. To do a good job of environmental health, Jeeves, traffic order rectification, and built underground pipe network, combined underground road network, underground parking, enhancing the overall image of the city. Fourth, we must adhere to the combination of "scientific planning" and "fine management". City "building, seven in charge". To continue to improve the urban development planning and the overall layout, coordinate and promote the construction of the new, transformation of the old city, center city by the pull framework to improve the function, dominated by government oriented society, by laying a solid foundation to gather popularity change. At the same time, to adhere to excellence to grasp the management. The establishment of headquarters specifically a technical standards group, is responsible for this thing catch. Including street lighting design and plaque size, elevation brush what color should be careful planning, elaborate design, careful management. 角形排列的孔，上部两个是安装主轴承的，下面一个是滑阀油活塞的工作油缸。安装主动转子主轴承孔口外侧安装平衡活塞套。 排气端座:排气端座下部的孔口是气体压缩终了的轴向排气口。排气端座上主轴承孔的外侧安装止推轴承，用轴承压盖将止推轴承外圈压在排气端座上。 吸气端座、机体、排气端座的相对位置是三体找正后靠它们之间的定位销来确定。即使是同一型号机器的各部件也不能随意搭配。机体部件中的各零件的端面相互是严密贴合的，通过橡胶圈或厌氧胶密封。吸、排气端座主轴承孔及机体孔之间同心是保证转子能正常工作的重要条件。 2)转子部件 转子部件由主动转子(一般为阳转子)、从动转子(一般为阴转子)、主轴承、止推轴承、轴承压盖、平衡活塞以及平衡活塞套等零件组成。 阴、阳转子是螺杆压缩机中最核心的零件。转子的加工精度、形位公差要求都很高，精加工后还必须做动平衡试验方可使用。主动转子通过联轴器与电机直联，并带动从动转子旋转。 主轴承一般采用滑动轴承，又叫主轴瓦，是支撑转子、承担径向力。主轴承内表面衬有一层耐磨合金，磨损较大或拉毛、拉伤时应更换。主轴承在工作中靠润滑油润滑，各油路必须通畅。更换新轴承时要采取“刮花”处理。 止推轴承:每个转子上一般装有一对止推轴承，而且是经过游隙测定后相反方向安装。止推轴承是克服转子工作时产生的轴向力(排气端压向areas of the introduction of social capital, improve urban management efficiency and effectiveness. Third, we must adhere to the "concerned about face saving" and "the importance of lining" combined. Premier Li Keqiang once pointed out: "the face is the style of the city, and the lining is the conscience of the city. In the improvement of the urban environment, not only to attention to face, we should pay more attention to the lining. To do a good job of environmental health, Jeeves, traffic order rectification, and built underground pipe network, combined underground road network, underground parking, enhancing the overall image of the city. Fourth, we must adhere to the combination of "scientific planning" and "fine management". City "building, seven in charge". To continue to improve the urban development planning and the overall layout, coordinate and promote the construction of the new, transformation of the old city, center city by the pull framework to improve the function, dominated by government oriented society, by laying a solid foundation to gather popularity change. At the same time, to adhere to excellence to grasp the management. The establishment of headquarters specifically a technical standards group, is responsible for this thing catch. Including street lighting design and plaque size, elevation brush what color should be careful planning, elaborate design, careful management. 吸气端)，并保持转子端面与吸、排气端座保持一定的间隙。转子排气 端面与排气端座的间隙是靠调整垫的厚度来调整的。如果测量排气端间隙大，则磨薄调整垫;如果测量排气端间隙小，则更换调整垫或增加一个调整垫。止推轴承的内圈是通过圆螺母及防松垫片(俗称王八垫)固定在转子上，外圈是通过轴承压 盖压紧在排气端座上。装配轴承压盖时要注意用力均匀，并随时盘动转子检查是否盘车过紧。把紧轴承压盖后，要测量转子的轴向和径向的串动量。此时，转子的轴向串动量应为0，径向串动量应小于0.005mm。 平衡活塞通过螺栓(或键)固定在主动转子上吸气侧的一端、在平衡活塞套中随转子一同旋转，承受油压来平衡一部分轴向力，作用是延长止推轴承的使用寿命。平衡活塞及平衡活塞套磨损严重时必须更换。 3)滑阀部件 滑阀部件主要由滑阀、滑阀导管、滑阀导管套、螺旋管、油活塞、指示器以及“O”型圈和密封环等零件组成。螺杆制冷压缩机最常用的能量调节方法就是在两个转子之间设置一个可以轴向移动的滑阀，即滑阀能量调节方法。如图2-14所示，滑阀位置改变，与滑阀固定端脱离，打开一条与吸气腔相通的通道，基元容积中的气体没有得到压缩就旁通回吸气腔，相当于改变了转子的有效工作长度。滑阀位置不同，旁通气体的量也不同，滑阀的连续移动，能量可以在10%,100%之间无级调节。滑阀位置的改变，也改变了径向排气口的位置，使原本设计好的内压比发生改变，压缩比减小，使功耗的变化与冷量的变化不成比例，效率降低。滑阀的另一个作用是将润滑油引入滑阀内部的空腔，并通过滑阀上的若干小孔将油喷到机体与转子之间。油在压缩机中的作用是润滑、冷却、密封和消声。因为螺杆压缩机向工作腔中喷入润滑油，所以称为喷油螺杆，也因此螺杆压缩机排气温度比较低。 areas of the introduction of social capital, improve urban management efficiency and effectiveness. Third, we must adhere to the "concerned about face saving" and "the importance of lining" combined. Premier Li Keqiang once pointed out: "the face is the style of the city, and the lining is the conscience of the city. In the improvement of the urban environment, not only to attention to face, we should pay more attention to the lining. To do a good job of environmental health, Jeeves, traffic order rectification, and built underground pipe network, combined underground road network, underground parking, enhancing the overall image of the city. Fourth, we must adhere to the combination of "scientific planning" and "fine management". City "building, seven in charge". To continue to improve the urban development planning and the overall layout, coordinate and promote the construction of the new, transformation of the old city, center city by the pull framework to improve the function, dominated by government oriented society, by laying a solid foundation to gather popularity change. At the same time, to adhere to excellence to grasp the management. The establishment of headquarters specifically a technical standards group, is responsible for this thing catch. Including street lighting design and plaque size, elevation brush what color should be careful planning, elaborate design, careful management. 滑阀的运动是靠油活塞运动带动的。油活塞在吸气端座的油缸内，油缸的两端有进出油孔与控制系统相连。螺杆制冷压缩机能量调节控制原理见图2-15。 4)轴封部件 对于开启式压缩机，驱动轴的一端要伸出机体外部，为了防止制冷剂向外泄漏或空气渗漏入系统，必须在轴的伸出部位及机体之间设置轴封装置。 如图2-16所示的弹簧式轴封，是由动环、静环、弹簧、弹簧座、压环和“O”型密封圈组成。其中动环、弹簧、弹簧座及动环胶圈装配在一起并随主动转子旋转而旋转，静环及静环胶圈装配在轴封压盖上相对于机体固定。弹簧提供给动、静环之间合适的压力。因此，安装轴封时要调整弹簧的弹力。胶圈是防止气体轴向泄漏，动、静环的贴合面是防止气体径向泄漏。螺杆压缩机的转速很高，动、静环表面的摩擦及发热量都很大。为了润滑动、静环之间的密封面、减少渗漏并带走热量，轴封室内充满润滑油，通过油泵把油不断地输送到轴封。因为主动转子轴伸出端处在排气侧，所以轴封工作位置所处压力为压缩机的排气压力，为保证轴封的正常工作，要求油压比排气压高0.15~0.3MPa 。 在轴封的前端，一般装有油封，其作用是保证轴封室内充满润滑油。 注意事项:对于氟利昂压缩机，“O”型圈应使用耐氟橡胶;轴封少量渗漏是允许的;润滑油中制冷剂过多会严重损坏轴封。 5)联轴器部件 areas of the introduction of social capital, improve urban management efficiency and effectiveness. Third, we must adhere to the "concerned about face saving" and "the importance of lining" combined. Premier Li Keqiang once pointed out: "the face is the style of the city, and the lining is the conscience of the city. In the improvement of the urban environment, not only to attention to face, we should pay more attention to the lining. To do a good job of environmental health, Jeeves, traffic order rectification, and built underground pipe network, combined underground road network, underground parking, enhancing the overall image of the city. Fourth, we must adhere to the combination of "scientific planning" and "fine management". City "building, seven in charge". To continue to improve the urban development planning and the overall layout, coordinate and promote the construction of the new, transformation of the old city, center city by the pull framework to improve the function, dominated by government oriented society, by laying a solid foundation to gather popularity change. At the same time, to adhere to excellence to grasp the management. The establishment of headquarters specifically a technical standards group, is responsible for this thing catch. Including street lighting design and plaque size, elevation brush what color should be careful planning, elaborate design, careful management. 螺杆压缩机的联轴器有橡胶柱销式和挠性(膜片式)联轴器两种。 橡胶柱销式联轴器由两个半联轴节、飞轮、传动芯子以及螺钉等组成。这种联轴器的橡胶传动芯容易磨损，磨损后会导致机器运动不平稳，对转子、轴承、轴封都会产生不良影响。目前逐渐被挠性联轴器取代。 挠性联轴器是由两半联轴节、接筒、传动垫片以及螺钉等组成。这种联轴器的两个半联轴节是经过动平衡试验的，安装时相对位置是固定的。 联轴器是将电动机的动力传递到压缩机主动转子的重要部件。由于螺杆压缩机的转速较高， 对联轴器的安装精度(同轴度)要求也较高。联轴器安装不当，不但会引起机器运转不平稳、噪声增高，而且对转子、主轴承、止推轴承和轴封会产生异常损伤。 对于新运行的机组，因为油分或机架的应力变化，会使压缩机、电机的同轴度发生改变，应定期检查同轴度，直至机组应力消除方可连续运转。 第三节 螺杆式制冷压缩机组与循环系统 1、螺杆制冷压缩机组 螺杆压缩机工作时要不断向工作腔喷入润滑油，起着润滑、冷却、密封和消声作用，以及润滑主轴承、止推轴承、轴封的润滑油，推动油活塞、平衡活塞的压力油，这些油最后和高压气体混合着排出压缩机。这些油必须分离出来，经过冷却、过滤、加压后循环使用。为防止制冷系统中的杂质随吸气进入压缩机对转子、机体造成磨损，必须设置吸气过滤器。 ?吸气过滤器 吸气过滤器主要由壳体和金属过滤网等组成。壳体上安装吸气温度计、areas of the introduction of social capital, improve urban management efficiency and effectiveness. Third, we must adhere to the "concerned about face saving" and "the importance of lining" combined. Premier Li Keqiang once pointed out: "the face is the style of the city, and the lining is the conscience of the city. In the improvement of the urban environment, not only to attention to face, we should pay more attention to the lining. To do a good job of environmental health, Jeeves, traffic order rectification, and built underground pipe network, combined underground road network, underground parking, enhancing the overall image of the city. Fourth, we must adhere to the combination of "scientific planning" and "fine management". City "building, seven in charge". To continue to improve the urban development planning and the overall layout, coordinate and promote the construction of the new, transformation of the old city, center city by the pull framework to improve the function, dominated by government oriented society, by laying a solid foundation to gather popularity change. At the same time, to adhere to excellence to grasp the management. The establishment of headquarters specifically a technical standards group, is responsible for this thing catch. Including street lighting design and plaque size, elevation brush what color should be careful planning, elaborate design, careful management. 压力表和加油阀。加油阀是机组运行时加油的部位。 注意事项: 拆卸端盖时防止被弹簧弹出伤人;安装时应注意过滤网一端的胶圈是完好的，如破损或变形应更换。 加油时通过调节吸气截止阀使吸气压力稍低于大气压，通过油管将油吸入，操作应缓慢进行。 对于氟利昂机组，蒸发温度比较低时，如果系统含水量比较大时，过滤器会出现冰堵现象。可以通过更换干燥过滤器滤去水分，也可以通过吸气过滤器过滤水分。如何判断和操作 ?油分离器 螺杆压缩机组的油分离器主要有立式和卧式两种，并且以填料式为主。我公司目前普遍采用卧式二级油分、三种分油方式，分油效率高，可达10PPm。油分离器并且也是压缩机、电机的基础，使机组结构紧凑。油分内部分隔成三个腔，靠压缩机一侧桶体是保持油位的，其外部壳体上有两个上下布置的视油镜，是监视油位高度(自动机组有油位控制器)。靠电机一侧的桶体是安装二次油分高效分油滤芯的，其外侧也有一个视areas of the introduction of social capital, improve urban management efficiency and effectiveness. Third, we must adhere to the "concerned about face saving" and "the importance of lining" combined. Premier Li Keqiang once pointed out: "the face is the style of the city, and the lining is the conscience of the city. In the improvement of the urban environment, not only to attention to face, we should pay more attention to the lining. To do a good job of environmental health, Jeeves, traffic order rectification, and built underground pipe network, combined underground road network, underground parking, enhancing the overall image of the city. Fourth, we must adhere to the combination of "scientific planning" and "fine management". City "building, seven in charge". To continue to improve the urban development planning and the overall layout, coordinate and promote the construction of the new, transformation of the old city, center city by the pull framework to improve the function, dominated by government oriented society, by laying a solid foundation to gather popularity change. At the same time, to adhere to excellence to grasp the management. The establishment of headquarters specifically a technical standards group, is responsible for this thing catch. Including street lighting design and plaque size, elevation brush what color should be careful planning, elaborate design, careful management. 油镜，根据油位判断是否采取回油措施。 注意事项: 油位控制:两个视油镜之间;分油滤芯前后部分筒内的回油操作油加热器的作用; 分油滤芯如果污染严重，会增加排气阻力，耗功增加，效率降低，应当更换;因为油分长度较长，受温度、振动的影响 会产生应力变形，使电机和压缩机的同轴度改变，压缩机初期运行时应随时调整同轴度。具体间隔时间由前次找正时测得的偏差植决定。 ?油冷却器 油分分离出来的润滑油因为吸收摩擦热及气体的热量而使温度升高(接近排气温度)。润滑油正常使用温度是30,60?，油温过高粘度降低，会使密封作用减弱，内泄漏增加，降低压缩机的效率，所以润滑油必须经过冷却才能循环使用。油冷却器就是起冷却油的作用。 一般油冷却器采用水冷却方式。油走壳程，水走管程，清洗水路方便。优点是系统简单，油 温可以降低至比较低的温度(根据水温而定);缺点是水侧管路易腐蚀。 工质冷却。油走管程，工质走壳程。优点是油冷不易腐蚀，操作维护简areas of the introduction of social capital, improve urban management efficiency and effectiveness. Third, we must adhere to the "concerned about face saving" and "the importance of lining" combined. Premier Li Keqiang once pointed out: "the face is the style of the city, and the lining is the conscience of the city. In the improvement of the urban environment, not only to attention to face, we should pay more attention to the lining. To do a good job of environmental health, Jeeves, traffic order rectification, and built underground pipe network, combined underground road network, underground parking, enhancing the overall image of the city. Fourth, we must adhere to the combination of "scientific planning" and "fine management". City "building, seven in charge". To continue to improve the urban development planning and the overall layout, coordinate and promote the construction of the new, transformation of the old city, center city by the pull framework to improve the function, dominated by government oriented society, by laying a solid foundation to gather popularity change. At the same time, to adhere to excellence to grasp the management. The establishment of headquarters specifically a technical standards group, is responsible for this thing catch. Including street lighting design and plaque size, elevation brush what color should be careful planning, elaborate design, careful management. 单;节省一套水路系统，适用于水质差或供水困难的场合;油温比较稳定。缺点是油温的最低温度受冷凝温度控制，系统需增加辅助贮液器或氨泵。辅助贮液器出液口与油冷之间至少要有1米以上的高度差。 ?粗油过滤器 为保护油泵的正常工作，在润滑油进入油泵之前通过粗油过滤器滤去杂质。过滤器由壳体和金属滤网组成，壳体上设有加油阀，初次加油都是通过此阀。加油可以通过系统抽真空加油，也可以通过油泵加油。对于初次运转的机器，初运转后要检查粗油过滤器的清洁度，并根据系统清洁度定期拆检过滤网。可使用汽油或煤油清洗过滤网，并用干燥空气吹干净后继续使用。 ?油泵 油泵在压缩机组中的作用是增加油压。常采用齿轮泵或转子泵。开机前要先检查油泵旋转方向。油泵齿轮或转子磨损严重会导致油压不足，必须检修或更换;油泵轴封漏油也必须检修或更换。 ?精油过滤器 精油过滤器也是由壳体和过滤网组成，装配在油泵之后、油分配器之前，过滤油中的细小颗粒，保护压缩机转子及轴封。为了能滤去细微的金属磨屑，在过滤网内装有永磁铁。 精油过滤器的过滤网比较细密，容易受到污染而使阻力增大。当油流经areas of the introduction of social capital, improve urban management efficiency and effectiveness. Third, we must adhere to the "concerned about face saving" and "the importance of lining" combined. Premier Li Keqiang once pointed out: "the face is the style of the city, and the lining is the conscience of the city. In the improvement of the urban environment, not only to attention to face, we should pay more attention to the lining. To do a good job of environmental health, Jeeves, traffic order rectification, and built underground pipe network, combined underground road network, underground parking, enhancing the overall image of the city. Fourth, we must adhere to the combination of "scientific planning" and "fine management". City "building, seven in charge". To continue to improve the urban development planning and the overall layout, coordinate and promote the construction of the new, transformation of the old city, center city by the pull framework to improve the function, dominated by government oriented society, by laying a solid foundation to gather popularity change. At the same time, to adhere to excellence to grasp the management. The establishment of headquarters specifically a technical standards group, is responsible for this thing catch. Including street lighting design and plaque size, elevation brush what color should be careful planning, elaborate design, careful management. 精油过滤器的压力降超过0.05,0.1Mpa时，就要对精滤器进行清洗或更换。机组设有精滤器前后压差保护，设定值为0.1Mpa。 ?油压调节阀 油压调节阀的作用是调节压缩机的喷油压力。如果进入压缩机的油压过高，会使喷油量过大，既影响压缩机的吸气量，又增加压缩机的耗功，还会增加轴封漏油的可能性;油压过低，会使喷油量过小，使润滑油的作用减弱。一般要求精油过滤器后的油压即喷油压力要比排气压力高0.15,0.3Mpa(可调内容积比压缩机除外)。 油压调节阀位一般于油泵进、出油管之间，一般是弹簧式的。当油泵出口压力高于油压调节阀设定值时，自动顶开调节阀的阀头，使一部分油流回进油管或油分，使油压降低。通常在刚开油泵或油温比较低时，油压会比较高，达到0.4~0.6MPa，此时不须要调整油压调节阀的设定值。机器运转正常后，根据需要将油压调整到合适值。 ?止回阀 止回阀又称止逆阀或单向阀。因为螺杆压缩机没有例似于活塞压缩机中的吸、排气阀片可以自动隔开高低压气腔，当压缩机突然停机而又没有来得及关闭吸排气截止阀，制冷剂气体就会从高压侧流向低压侧，同时压缩机转子也会在气流的作用下出现倒转现象。螺杆压缩机倒转会产生很多恶劣的影响:转子会产生严重的磨损;低压侧(蒸发器)压力升高，温度上升;压缩机中的润滑油会随气流大量流向低压侧，会使机组油量不足，影响蒸发器换热，或再次开机出现液击现象。 螺杆压缩机在吸气截止阀与机体吸气口之间、油分出口与排气截止阀之间设有吸气单向阀和排气单向阀，用以防止制冷剂气体反方向流动。不areas of the introduction of social capital, improve urban management efficiency and effectiveness. Third, we must adhere to the "concerned about face saving" and "the importance of lining" combined. Premier Li Keqiang once pointed out: "the face is the style of the city, and the lining is the conscience of the city. In the improvement of the urban environment, not only to attention to face, we should pay more attention to the lining. To do a good job of environmental health, Jeeves, traffic order rectification, and built underground pipe network, combined underground road network, underground parking, enhancing the overall image of the city. Fourth, we must adhere to the combination of "scientific planning" and "fine management". City "building, seven in charge". To continue to improve the urban development planning and the overall layout, coordinate and promote the construction of the new, transformation of the old city, center city by the pull framework to improve the function, dominated by government oriented society, by laying a solid foundation to gather popularity change. At the same time, to adhere to excellence to grasp the management. The establishment of headquarters specifically a technical standards group, is responsible for this thing catch. Including street lighting design and plaque size, elevation brush what color should be careful planning, elaborate design, careful management. 能把单向阀做为截止阀使用。吸、排气止 回阀安装时应注意方向，不可倒置。 在机体吸气口和油分之间设还有一个电磁阀(俗称B阀)，人为停机时，电磁阀打开，使压缩机吸、排气口压力迅速平衡，减轻压缩机在停机时倒转。 2、单级螺杆制冷压缩机组系统、润滑与控制 (1)压缩机组系统 单级螺杆制冷压缩机组一般由压缩机、电动机、吸气过滤器、油分离器、油冷却器、油过滤器、油泵、止回阀以及电气控制台组成，安装在同一公共底座上。电气启动柜一般集中在一个控制室内。 (2)润滑与喷油 螺杆制冷压缩机有内油路和外油路两种。不论那种油路，以下各点都应保证润滑: a.滑阀喷油 b.平衡活塞喷油 c.滑阀导轨喷油 d.吸、排气端主轴承及止推轴承喷油 e.轴封喷油 areas of the introduction of social capital, improve urban management efficiency and effectiveness. Third, we must adhere to the "concerned about face saving" and "the importance of lining" combined. Premier Li Keqiang once pointed out: "the face is the style of the city, and the lining is the conscience of the city. In the improvement of the urban environment, not only to attention to face, we should pay more attention to the lining. To do a good job of environmental health, Jeeves, traffic order rectification, and built underground pipe network, combined underground road network, underground parking, enhancing the overall image of the city. Fourth, we must adhere to the combination of "scientific planning" and "fine management". City "building, seven in charge". To continue to improve the urban development planning and the overall layout, coordinate and promote the construction of the new, transformation of the old city, center city by the pull framework to improve the function, dominated by government oriented society, by laying a solid foundation to gather popularity change. At the same time, to adhere to excellence to grasp the management. The establishment of headquarters specifically a technical standards group, is responsible for this thing catch. Including street lighting design and plaque size, elevation brush what color should be careful planning, elaborate design, careful management. (3)控制与保护 螺杆制冷压缩机组的控制一般分为全自动型和手动操作加自动保护型。不论那种类型，都应设置下列自动保护: a.主电机过载保护 b.排气压力高保护:?1.57MPa c.喷油温度高保护:?65? d.油压与排气压力差保护:?0.10 MPa e.精油过滤器前后压差高保护:?0.1MPa f.吸气压力低保护:根据工况设定 3、带经济器的螺杆制冷循环系统 螺杆压缩机的特点之一是单级压比大，但随着压比增大，压缩机的内泄漏增加，效率降低，耗功大。利用螺杆压缩机的吸气、压缩、排气单向进行的特点，在转子转动到开始压缩的某一位置设置一个中间补气孔，补入中间压力下的制冷剂气体，使单级螺杆按两极压缩运转，相当于准双级，即为带经济器的螺杆压缩机。 带经济器的螺杆制冷循环系统又称为节能系统。如图2-18所示的为带经济器的一级节流循环原理图。 areas of the introduction of social capital, improve urban management efficiency and effectiveness. Third, we must adhere to the "concerned about face saving" and "the importance of lining" combined. Premier Li Keqiang once pointed out: "the face is the style of the city, and the lining is the conscience of the city. In the improvement of the urban environment, not only to attention to face, we should pay more attention to the lining. To do a good job of environmental health, Jeeves, traffic order rectification, and built underground pipe network, combined underground road network, underground parking, enhancing the overall image of the city. Fourth, we must adhere to the combination of "scientific planning" and "fine management". City "building, seven in charge". To continue to improve the urban development planning and the overall layout, coordinate and promote the construction of the new, transformation of the old city, center city by the pull framework to improve the function, dominated by government oriented society, by laying a solid foundation to gather popularity change. At the same time, to adhere to excellence to grasp the management. The establishment of headquarters specifically a technical standards group, is responsible for this thing catch. Including street lighting design and plaque size, elevation brush what color should be careful planning, elaborate design, careful management. A—压缩机 B—油分离器 C—冷凝器 S—贮液器 J—经济器 E—蒸发器 P—油泵 F—油冷 G1—节流阀1 G2—节流阀2 经济器为壳管式换热器，壳程为低压侧，管程为高压侧。经济器上配带补气过滤器、止回阀、节流阀等配件。当压比发生变化时，要根据中间补气的过热度适当调节节流阀的供液量，防止回液，尤其是采用热力膨胀阀供液的氟利昂系统。 带经济器的螺杆压缩机组常用于蒸发温度为-25~-40?的制冷系统。与原来的单级压缩机相比，制冷量、制冷效率都有了大幅的提高，同时还节省电能。见图2-19所示，为带经济器的氨螺杆压缩机制冷量、轴功率的增加率跟温度的关系，可见轴功率变化比较平缓，而制冷量随蒸发温度的降低增加率增高，并且压比越大，增加的效果越显著。 areas of the introduction of social capital, improve urban management efficiency and effectiveness. Third, we must adhere to the "concerned about face saving" and "the importance of lining" combined. Premier Li Keqiang once pointed out: "the face is the style of the city, and the lining is the conscience of the city. In the improvement of the urban environment, not only to attention to face, we should pay more attention to the lining. To do a good job of environmental health, Jeeves, traffic order rectification, and built underground pipe network, combined underground road network, underground parking, enhancing the overall image of the city. Fourth, we must adhere to the combination of "scientific planning" and "fine management". City "building, seven in charge". To continue to improve the urban development planning and the overall layout, coordinate and promote the construction of the new, transformation of the old city, center city by the pull framework to improve the function, dominated by government oriented society, by laying a solid foundation to gather popularity change. At the same time, to adhere to excellence to grasp the management. The establishment of headquarters specifically a technical standards group, is responsible for this thing catch. Including street lighting design and plaque size, elevation brush what color should be careful planning, elaborate design, careful management. 4、螺杆液氨冷却压缩机组 采用液氨油冷却器的压缩机组。适用于水质差、供水困难或水成本高的场合;油温比较稳定。缺点是油温的最低温度受冷凝温度控制，系统需增加辅助贮液器或氨泵。采用辅助贮液器时辅助贮液器的出液口与油冷之间至少要有1米以上的高度差。 5、螺杆冷水机组 将螺杆压缩机组与蒸发器、冷凝器、干燥过滤器、电磁阀及热力膨胀阀等组合在一个公共底座上，采用水作为载冷剂的机组。冷水机组常采用R22作为制冷剂，并采用热力膨胀阀自动调节供液量。目前也有采用氨作为制冷剂、板式换热器作为蒸发器和冷凝器。采用壳管换热器可制取4,15?的空调或冷却用水;而采用板式换热器可制取1?左右的冷水。冷水机组除了有正常压缩机组的自动保护外，还有冷水、冷却水断水保护及冷水水温低保护。 热力膨胀阀:由感温包、毛细管、弹性膜片、弹簧、阀芯、阀座及调节装置等组成。感温包是绑在靠近压缩机的吸气管路上的，利用感温包内的制冷剂饱和温度与饱和压力的对应关系，温度变化时压力也发生变化，改变阀芯的开启度，调节膨胀阀的供液量。调节装置是用来改变弹簧压在膜片上的弹力的，从而改变吸气过热度。 6、螺杆盐水(乙二醇)机组 结构与冷水机组相似，采用盐水(乙二醇溶液)作为载冷剂，制取-10,-40?的低温盐水(乙二醇溶液)。由于盐水有腐蚀性，盐水机组的蒸发器内的换热管采用耐低温、耐腐蚀的高效黄铜管制成。盐水(乙二醇)areas of the introduction of social capital, improve urban management efficiency and effectiveness. Third, we must adhere to the "concerned about face saving" and "the importance of lining" combined. Premier Li Keqiang once pointed out: "the face is the style of the city, and the lining is the conscience of the city. In the improvement of the urban environment, not only to attention to face, we should pay more attention to the lining. To do a good job of environmental health, Jeeves, traffic order rectification, and built underground pipe network, combined underground road network, underground parking, enhancing the overall image of the city. Fourth, we must adhere to the combination of "scientific planning" and "fine management". City "building, seven in charge". To continue to improve the urban development planning and the overall layout, coordinate and promote the construction of the new, transformation of the old city, center city by the pull framework to improve the function, dominated by government oriented society, by laying a solid foundation to gather popularity change. At the same time, to adhere to excellence to grasp the management. The establishment of headquarters specifically a technical standards group, is responsible for this thing catch. Including street lighting design and plaque size, elevation brush what color should be careful planning, elaborate design, careful management. 机组蒸发温度比较低，初期运行时要注意观察吸气过滤器是否出现冰 堵。 areas of the introduction of social capital, improve urban management efficiency and effectiveness. Third, we must adhere to the "concerned about face saving" and "the importance of lining" combined. Premier Li Keqiang once pointed out: "the face is the style of the city, and the lining is the conscience of the city. In the improvement of the urban environment, not only to attention to face, we should pay more attention to the lining. To do a good job of environmental health, Jeeves, traffic order rectification, and built underground pipe network, combined underground road network, underground parking, enhancing the overall image of the city. Fourth, we must adhere to the combination of "scientific planning" and "fine management". City "building, seven in charge". To continue to improve the urban development planning and the overall layout, coordinate and promote the construction of the new, transformation of the old city, center city by the pull framework to improve the function, dominated by government oriented society, by laying a solid foundation to gather popularity change. At the same time, to adhere to excellence to grasp the management. The establishment of headquarters specifically a technical standards group, is responsible for this thing catch. Including street lighting design and plaque size, elevation brush what color should be careful planning, elaborate design, careful management.