Variable Displacement Compressor Automotive Air Conditioning Study on thermal expansion valve Abstract Through a variable displacement compressor for automotive air conditioning refrigeration systems Experimental study on thermal expansion valve, obtained in the static superheating expansion valve settings, gain and hysteresis, temperature and other packet time constant static and dynamic characteristics，and the test results are analyzed. Keywords: Thermal Expansion Valve Auto Air Conditioner Compressor Variable Displacement Study 1 Introduction Automotive air-conditioning system shake plate stepless variable displacement compressor (hereinafter referred to as variable displacement compressor) is based on the difference between compressor suction pressure to promote the swinging plates to change the tilt angle, thus changing the piston stroke and compressor for each spindle turn displacement week. Therefore, these variable displacement compressor has changed the traditional conditioning compressor clutch hoist way, the compressor runs continuously stable, do not cause car engines periodic load change, and air-conditioning supply air temperature fluctuation is small, will help improve vehicle environment within the thermal comfort; can be maintained almost constant and slightly higher than the frost temperature，evaporation temperature, to prevent the surface of the evaporator frost and improve the system dehumidification capability; can reduce energy consumption and save fuel.
可变排量压缩机 汽车空调热力膨胀阀的研究摘要 通过可变排量压缩机用于汽车空调制冷系统 热力膨胀阀的实验研究，得到了在静态过热膨胀阀设置、增益和滞后、温度等分组时间常数的静态和动态特性，并对试验结果进行了分析。关键词： 热力膨胀阀 汽车空调压缩机 变排量研究 1 引言 汽车空调系统 摇盘式无级变排量压缩机（以下简称变排量压缩机）是根据压缩机吸气压力差推动摆动板改变倾斜角度，从而改变活塞行程和压缩机对每个主轴转排量周的排量。因此，这些可变排量压缩机改变了传统压缩机离合提升机的调节方式，使压缩机连续稳定运行，不会引起汽车发动机负荷的周期性变化，而且空调送风温度波动小，将有助于改善车内环境的热舒适性;可保持几乎恒定且略高于霜冻温度、蒸发温度，防止蒸发器表面结霜，提高系统除湿能力;可降低能耗，节省燃料。

From the car air-conditioning system replaced by a variable displacement compressor fixed displacement compressor general trend of development, variable displacement compressor will be non-standard automobile air conditioning systems in particular, a variety of luxury vehicles have air-conditioning system is widely 应用.
从汽车空调系统取代变排量压缩机定排量压缩机发展的大势所趋，变排量压缩机将非标汽车空调系统尤其如此，各种豪华车都有空调系统得到广泛应用。

Thermal expansion valve is widely used in refrigeration system throttling device, but it is with the variable displacement compressor for automotive air conditioning cooling system composed of the actual use of the system stability problems occur. At-suo Inoue and others in the seven-cylinder variable displacement compressors and thermal expansion valve for automotive air conditioning refrigeration systems composed of a pilot study found that this phenomenon exists in the system oscillation. 美 国 GMCompany stepless variable displacement compressors and thermal expansion valve for automotive air conditioning refrigeration systems application process, also have the same discovery. We used a model of variable displacement compressors and thermal expansion valve automotive air conditioning system stability problems have been studied, in order to detailed analysis of variable displacement compressors and thermal expansion valve parameters of the coupling between pairs of the system stability, the need for thermal expansion valve of the system dynamic line of conduct in-depth understanding.
热力膨胀阀是制冷系统中广泛使用的节流装置，但它是与汽车空调冷却系统组成的可变排量压缩机一起，在实际使用中出现系统的稳定性问题。At-suo Inoue 等人在对汽车空调制冷系统的七缸可变排量压缩机和热膨胀阀组成的中试研究中发现，这种现象存在于系统振荡中。美国GM公司无级可变排量压缩机和热膨胀阀用于汽车空调制冷系统的应用过程，也有同样的发现。我们采用的可变排量压缩机模型和热力膨胀阀对汽车空调系统的稳定性问题进行了研究，为了详细分析可变排量压缩机和热力膨胀阀参数对系统之间的耦合稳定性，需要深入了解热力膨胀阀的系统动力学路线。

Figure 1 shows our study variable displacement compressor car air conditioning system Schematic diagram of thermal expansion valve. The thermal expansion valve is outside the balanced, temperature pack as a gas filling, and there are two commonly used thermal expansion valve with different: (1) thermal expansion valve is used bias-type, and the thermal expansion valve is balanced, and required force to open valve is small, the basic force against valve stem pressure on the size of the import and export.
图 1 显示了我们研究的可变排量压缩机汽车空调系统的热膨胀阀示意图。热力膨胀阀是外平衡的，温度包作为充气的，与常用的热力膨胀阀有两种不同：（1）热力膨胀阀采用偏压式，而热力膨胀阀是平衡的，且打开阀门所需的力很小，基本力对阀杆压力的大小取决于进出口。

(2) The thermal expansion valve’ s static superheat is negative, that is, when superheat is zero, the valve can not be completely closed, there is still a trace of refrigerant flow.
（2）热力膨胀阀的静态过热度为负，即当过热度为零时，阀门不能完全关闭，仍有微量的制冷剂流动。

Figure 1 Structure of thermal expansion valve This article describes the thermal expansion valve superheat setting a static value, gain and hysteresis, temperature package time constant testing methods and test results, and experimental data for analysis.
图 1 热力膨胀阀的结构本文介绍了热力膨胀阀的过热度设置静态值、增益和滞后、温度包时间常数的测试方法和测试结果，以及用于分析的实验数据。

2 test equipment and test methods Test the light JRA2014-1996 standard “automotive air-conditioning (HFC-134a) with the thermal expansion valve” and the thermal expansion valve factory standard conducted tests using ammonia refrigerant. Pressure measurement using RH-ACPS-A-type high-voltage output type pressure sensor, temperature measurement through the standard use of copper - constantan thermocouple, expansion valve opening measured by DA differential transformer displacement sensors, all the measured parameters used HP34970A Data Acquisition Instrument inspection records.
2 试验设备和试验方法 试验轻型 JRA2014-1996 标准“汽车空调（HFC-134a） 用热力膨胀阀”和热力膨胀阀出厂标准使用氨制冷剂进行的试验。压力测量采用RH-ACPS-A型高压输出型压力传感器，温度测量采用铜-康铜热电偶，膨胀阀开度采用DA差动变压器位移传感器测量，所有测量参数均采用数据采集仪HP34970A检验记录。

2.1 Static superheat setting Figure 2 shows the static superheat setting diagram of experimental device. In accordance with the static thermal expansion valve superheat set value require the installation of the exhaust vent aperture of 1.3mm will be placed in a thermal bag of ice temperature of 0 ℃ in coagulation complexes，regulating valve before the pressure control valve so that a constant pressure of P1 In the 1.378Mpa, read the back pressure valve P2, you can determine the static superheat setting.
2.1 静态过热度设定 图 2 显示了实验装置的静态过热度设定图。按照静热膨胀阀的过热度设定值要求，安装排气口孔径为1.3mm，将置于保温袋中，冰温为0°C的混凝装置中，调节阀前加压控制阀，使P1的恒定压力在1.378Mpa，读取背压阀P2， 您可以确定静态过热度设置。

Figure 2 Static superheat setting test device 2.2 gain and hysteresis Figure 3 for the gain and hysteresis diagram of experimental device. The temperature bag placed in a temperature of 0 ℃ compounds in the coagulation of ice water, regulating pressure control valve to change the external balance pipe pressure to change the thermal expansion valve opening.
图 2 静态过热度设置测试装置 2.2 增益和滞后 图 3 为实验装置的增益和滞后图。将温度袋置于温度为0°C的化合物中，使冰水凝结，调节压力控制阀，改变外部平衡管压力，改变热力膨胀阀的开度。

Nitrogen without a thermal expansion valve, but directly from the exhaust vent. First interval at a certain pressure difference increases from small to large external balance pipe pressure，measured thermal expansion valve opening, and then a certain pressure difference interval from biggest to smallest decrease in the pressure balance pipe to measure thermal expansion valve opening.
氮气没有热力膨胀阀，而是直接从排气口排出。首先在一定压力差处由小到大增加外部平衡管压力，测量热膨胀阀开度，然后以一定压力差间隔从最大到最小减小平衡管压力，测量热膨胀阀开度。

Figure 3 Gain and hysteresis testing device Thermal time constant of 2.3 packets Thermal time constant of the measuring device package with the static superheat setting test device, but make the original temperature of a thermostat bath to two different (at least a difference of 10 ℃) of the thermostat bath. Regulating valve before the pressure control valve so that a constant pressure P1 in the 1.378Mpa, the thermal pack to put at a lower constant temperature bath until the temperature stability, and then rapidly from a low temperature pack temperature moved to a higher temperature thermostat bath constant temperature bath, such as thermal stability of the package and then rapidly from a high temperature thermostat bath moved to a lower constant temperature bath until the temperature stable. Records of temperature-sensitive packages throughout the process temperature and valve after the pressure change.
图 3 增益和滞后测试装置 热时间常数 2.3 包热时间常数 测量装置封装有静态过热度设定测试装置，但使恒温槽的原始温度达到两个不同的（至少相差 10 °C）的恒温槽。调节阀前加压控制阀，使恒压P1在1.378Mpa，将热能组置于较低的恒温槽中，直至温度稳定，然后迅速从低温组温移至较高温度的恒温槽恒温槽，如热稳定，包体再迅速从高温恒温槽移至较低的恒温槽，直至温度稳定。压力变化后整个过程温度和阀门的温度敏感包装记录。

3 Experimental results and analysis 3.1 Static superheat setting In accordance with the static thermal expansion valve superheat setting the conditions for determination of static superheat setting out the value is -0.5 ℃, with the valve provided in the sample (-0.3 ± 0.8) ℃ static superheat setting values. General static thermal expansion valve superheat setting is positive, but this study the static thermal expansion valve superheat setting value is negative. In other words, when the superheat is zero, the valve is not fully closed, there is still a small flow of refrigerant flow.
3 实验结果及分析 3.1 静态过热度设定 按照静态热膨胀阀过热度设定条件确定，定静态过热度定型值为-0.5°C，用阀门提供的样品（-0.3±0.8°C）°C静态过热度设定值。一般静热膨胀阀过热度设定值为正，但本研究静态热膨胀阀过热度设定值为负。换句话说，当过热度为零时，阀门没有完全关闭，制冷剂流量仍然很小。

In stepless variable displacement compressors and thermal expansion valve refrigeration system for automotive air conditioning found that changes in thermal expansion valve opening and compressor plate tilt angle of adjustment will be rocking the interaction, thus exacerbating the instability of system operation. When the evaporator load decreases, the evaporator outlet superheat decreases, thermal expansion valve opening and flow rate decreased; the same time, the pressure to reduce evaporation, making compressor swinging plates become smaller and even the tilt angle displacement compressor also decreases, and because the regulatory role of the thermal expansion valve allows emission reductions to increase. When the refrigerant flow rate is very small，especially in the thermal expansion valve suddenly opened，the run will become very unstable. Therefore, in order to meet the stepless variable displacement compressors and thermal expansion valve automotive air conditioning refrigeration systems the special requirements of such systems to eliminate or reduce the oscillation problems, using the static superheat setting a negative way, making thermal expansion valve to open degrees off to a minimum, there is still a small flow of refrigerant flow.
在无级可变排量压缩机和热膨胀阀制冷系统中发现，热膨胀阀开度的变化和压缩机板倾斜角度的调节会相互作用，从而加剧系统运行的不稳定性。当蒸发器负荷降低时，蒸发器出口过热度降低，热力膨胀阀开度和流量降低;同时，压力降低蒸发，使压缩机摆动板变小，甚至倾斜角排量压缩机也减小，并且由于热力膨胀阀的调节作用使减排量增加。当制冷剂流量非常小时，特别是在热力膨胀阀突然打开的情况下，运行会变得非常不稳定。因此，为了满足汽车空调制冷系统中无级变排量压缩机和热力膨胀阀的特殊要求，要消除或减少此类系统的振荡问题，采用静态过热度设定负的方式，使热力膨胀阀的开度关到最低，制冷剂流量仍然很小。

Reposted elsewhere in the paper for free download 3.2 gain and hysteresis Thermal expansion valve opening pressure with the external balance pipe changes in Figure 4. The points indicate test chart measured data, the curve is based on experimental data obtained by the method of least squares quadratic fitting curve; above a set of data for the external balance pipe pressure changes in both large and small opening, following a group outside the Pressure balance between the opening degree of change from childhood to Tai. Kexin be seen from the figure, with the external balance pipe pressure increasing，making thermal expansion valve are getting smaller and smaller degree of overheating, then the opening became smaller and smaller. The slope of the curve known as the thermal expansion valve gain, expressed as a balance pipe outside the unit change in opening pressure. Horizontal distance between two curves is the expansion valve hysteresis，hysteresis can be seen in the middle of a larger valve opening，in the closed or open a smaller office.
转贴于本文的其他地方免费下载 3.2 增益和滞后 热膨胀阀打开压力随外部平衡管的变化，如图 4 所示。点表示测试图表测量数据，曲线基于通过最小二乘二次拟合曲线方法获得的实验数据;以上一组数据为外平衡管开度大、小开度变化，跟着一组外压平衡管开度变化程度从童年到台。从图中可以看出，随着外部平衡管压力的增加，使得热力膨胀阀的过热程度越来越小，然后开口越来越小。曲线的斜率称为热力膨胀阀增益，表示为装置外的平衡管在开启压力的变化。两条曲线之间的水平距离是膨胀阀的滞后性，滞后可见于阀门开口较大、关闭或打开较小办公室的中间。

Figure 4 opening and hysteresis loop (temperature pack temperature 0 ℃) Studies have shown that the gain of thermal expansion valve refrigeration system that affect the stability of an important factor, the greater the gain, the system more prone to oscillation; in a certain gain range, the expansion valve hysteresis can also cause the system vibration Pinene; oscillation The amplitude and gain and the size of the hysteresis loop is proportional to, so to reduce the growth rate of benefits and expansion valve hysteresis can increase system stability.
图4 开度和滞后回路（温度组温度0°C）研究表明，热力膨胀阀制冷系统的增益是影响稳定性的重要因素，增益越大，系统越容易出现振荡;在一定的增益范围内，膨胀阀的滞后也会引起系统振动 Pinene;振荡 振幅和增益与磁滞回线的大小成正比，因此降低增长率的好处和膨胀阀磁滞可以提高系统的稳定性。

Thermal time constant of 3.3 packets Back pressure valve package P2 Essay temperature rise when the temperature dips sudden changes in the process shown in Figure 5, the time constant for the valve after the pressure change to its full variation 63.2% of the time. Derived from the experimental data, thermal bag when the sudden increase in the temperature time constant is the 12s, but a sudden drop in temperature when the package temperature time constant is the 5s, so you can see a sudden rise in temperature of temperature-sensitive packets through the thermal time constant Pack a sudden drop in temperature when the time constant is much greater.
热时间常数 3.3 包背压阀组 P2 论文 温度上升 当温度骤降时 过程急剧变化 如图 5 所示，该时间常数为阀门在压力变化后其全部变化的 63.2% 时间。从实验数据得出，保温袋时温度突然升高的时间常数是 12s，但当封装温度时间常数突然下降时是 5s，所以你可以看到温度敏感包的温度突然升高，通过热时间常数包装时温度突然下降，时间常数要大得多。

Figure 5 when the temperature-sensitive mutant P2 package temperature of the change process Thermal expansion valve thermal time constant of this dynamic feature package is a package due to thermal lag can be placed on a working fluid filling but filling of the gasification of the condensed working fluid have little bearing on the objects, making sense of feel the temperature of warm package changes from high to low, which the working fluid filling rapidly liquefied at the surface, while in the temperature-sensitive package by temperature changes from low to high evaporation gasification slower. In the evaporator exit superheat, when a sudden decrease, temperature makes the packet-dump time constant of thermal expansion valve closes quickly, small (or closed), to avoid the large time lag makes it wet steam into the compressor; and when the evaporator outlet superheat temperature rises, temperature rise time constant of a larger package makes the thermal expansion valve motion lag curb valve to play the role of the regulation of oscillation.
图 5 当温度敏感突变体 P2 包温度变化过程热膨胀阀热时常数的这个动态特征包是一个包由于热滞后可以放置在一个工作流体上填充但填充的气化的冷凝工作流体对物体几乎没有影响，感觉温暖的包的温度由高到低变化， 其中填充的工作液在表面迅速液化，而在温度敏感的包装中，受温度从低到高的变化，气化速度较慢。在蒸发器出口过热度时，当温度突然下降时，温度使热力膨胀阀的排包时间常数迅速关闭，小（或关闭），避免了大的时间滞后使其湿蒸汽进入压缩机;而当蒸发器出口过热温度升高时，较大封装的升温时间常数使得热力膨胀阀的运动滞后节压阀起到调节振荡的作用。

4 Conclusion In this paper, a model of the variable displacement compressor for automotive air conditioning refrigeration systems Experimental study on thermal expansion valve，obtained in the static superheating expansion valve settings，gain and hysteresis, temperature and other packet time constant static and dynamics. In order to eliminate or alleviate the refrigerant flow of the system oscillation problem, the use of negative static expansion valve superheat set value; and thermal expansion valve gain and hysteresis of the draw can be used to analyze the stability of the system; in the evaporator exported sudden drop in heat when the temperature of a sudden drop in temperature when the package the smaller the time constant can be realized on the compressor protection, and a sudden rise in temperature when the package temperature of the larger time constant can inhibit the regulation of valve oscillation. The results of this study for the analysis of variable displacement compressors and thermal expansion valve for automotive air conditioning refrigeration systems composed of the stability of the foundation.
4 结论 本文建立了汽车空调制冷系统用可变排量压缩机模型的热膨胀阀实验研究，得到了在静态过热膨胀阀设置、增益和滞后、温度等分组时间常数静态和动力学下的表现。为了消除或缓解制冷剂流动的系统振荡问题，采用负静态膨胀阀过热度设定值;热膨胀阀的增益和抽取的滞后可用于分析系统的稳定性;在蒸发器出口时，热量突然下降时，温度突然下降时，机组的时间常数越小，就可以实现对压缩机的保护，而当机组温度突然升高时，时间常数越大，可以抑制阀门振荡的调节。本研究结果用于分析由汽车空调制冷系统组成的可变排量压缩机和热膨胀阀的稳定性基础。

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