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1、浙江师范大学本科毕业设计(论文)外文翻译译文：节能 制冷 摘要：本为介绍一种家居冰箱，每天用电大约0.1度的电。提供卓越的冰箱食品保存的表现，因为在其内部的温度波动日常使用过程中自然减少。这款冰箱比一般家居市场上的冰箱能量效率好10到20倍。而其中目前而言，最大的问题是如何提高能源效率和食品保护。家庭生活中的冰箱已经是人们的生活习惯，而不是技术成本。卧式冰柜各种市场上的制冷设备表明，设计良好的冰柜每天消耗电力的多少和冰箱的体积相比较，即冷冻室和外部的温差的大小（其内部有多少冷却器决定）。虽然冰柜通常有更好的保温和更大的蒸发器比冰箱，还有另一个重要原因是他们的效率。而垂直门的制冷设备本身的效率就
2、不高。而当我们打开一个立式冰箱的门这时冷空气就会溢出，只是因为房间中空气的温度比他本身的温度高。当我们打开一个卧式冰柜这时冷空气会停留在里面，是因为他重于房间空气的温度。任何在垂直门泄露的寒气（没有任何门是完美的）对于冰箱的效率会造成重大的损失。与此相反，即使我们打开卧式冰柜的大门，冷空气由于自身重量还会留在里面。制冷设备的设计和市场上营销的垂直门都是针对自然中的寒冷空气。我们应该适用他的工作性质而不是极力的反对他。只要有一个高效的“卧式冰柜”即可。相应的接触后发现一些领先的冰箱制造商并没有测试过冰箱的冰柜，所以我决定自己来进行测试。我买了一个精心设计的卧式冰柜（Vestfrost SE255
3、与600A的卧式冰柜制冷剂），并把其装在一个冰箱里。冷冻式转换冰箱主要区别冰柜和一个普通冰箱保持温度两者之间的区别。其中冷冻式维持零点温度（结冰温度）低至-25，而冰箱的操作介于4和10之间。因此，用冷冻机的方法来改变冰箱的温度控制。而不是用来干扰冰箱的温度，我决定恒温时切断电源来安装外置温度控制器，使温度达到我所选择的温度。如图1为说明框图。图1 说明框图 接线图（如图1）是一个很简单的图。其中温控器继电器消减冰箱的功耗。热敏电阻（温度传感器）是放置在冰箱里面的软电缆里。我使用了冰箱的排水孔来通过内部的热敏电阻电缆的冷却车厢。我同样去除了冰箱内部的灯泡，使用额定15瓦的灯泡，避免浪费能源，如
4、图1为我制作的冰柜冰箱的电子温控器接线盒热敏电阻的数控图。接线图是转换卧式冰柜为冰柜冰箱。通过有源连接传递恒温器内的继电器端子。作为一个原始的问题。如果我是在一个黑暗中打开冰箱，可能会考虑在冰箱内部安装一个LED的室内照明。温控器设计简单的设计一个真正好用的冰箱，其中的恒温系统是很重要的。只有当一个人在接受挑战为目的设计一个符合所需系统的标准作品的时候会面临一些意想不到的问题，这对于自身是一个很好的学习。温控器要求1、可靠性。冰箱是一个非常需要很好可靠性的家庭电器设备，而我们的健康也取决于冰箱的可靠性。由于任何温度波动产生使恒温器失灵的加速食物变质和引进相关的健康问题。温控器可最多无人工作几十
5、年。2、安全。在240V电源的冰箱应该很好地隔绝所有低电压恒温器的电子元件。3、零电压（240V）功率消耗的待机时间（当冰箱压缩机关闭时）。这项规定的规定情况是，一个冰箱（一个太阳能供电的冰柜冰箱）在转变为电源时按需检测功能的能力。使用一个允许逆变器的功率电器每天可以节省0.4千瓦的电，在冰箱进入待机（休眠）模式的时候。逆变器为基础可节约能源高达0.4千瓦/天，当然还需要考虑在日常日常能源消耗方面为0.1千瓦的冰柜冰箱。而该功率的最大挑战竟然是恒温设计。4、迟滞。冰箱压缩机的数量每小时起动应保持在较低水平，不仅以节约能源，而且还减少压缩机磨损。5、温控器应易于安装和应该不需要任何的修改冷冻机，
6、使新的冰箱保修期不能以任何方式损害。6、温控器应该是简单和容易并且是组建成本最低的组件。设计如图2所描述，这是一个组成最小可能的妥协功耗，简单性和成本的系统。温度传感系统由热敏电阻R1与一个运算放大器组成。该LM324的四运算放大器的选择是由于他有相当低的功耗（0.7mV），并能单电压供电运转，大大简化了设计。U1C和U1D作为缓冲区，以减少耗电量的体温测量和比较系统到可以忽略不计值。U1B上是一个加法放大器。U1A的是一个易于调整施密特触发迟滞（通过改变管13），设置在这里约-0.5。电容C4阻止无线电信号，可出现在长热敏电阻R1的电缆从而干预运作系统。开关SW1解决了系统下的供电问题（中心
7、断开位置），使恒温器工作在两种模式：由240伏电源供电（“SW1的上升”，其中如果电池可以去掉），并从电池（“SW1的下降”，零待机功耗模式）。“SW1的注册”模式还解决了电池初始充电的问题。 注意微功率作为LM29365V稳压器。通常将LM7805用于通过消耗比本身5倍更多的电路，但会阻碍整个系统变为微功率。使用LM7805会使电池放电循环5次深入，因此需要5倍大容量电池持续行动，更不用提一个较大的变压器保持电池充电。在“SW1的下降”模式下，当冰箱压缩机的继电器关闭时电池充电，对于我设计的冰箱，1间为1小时2分钟。热敏电阻的电路是由电池供电，它无需任何功耗的240V电源供电。 在系统操作中
8、，标称8.4V的镍氢电池电压在9.2V和9.4V之间变化，因此，在实践中的电池仍然能完全充电，因此可以使用多年。 图2 设计电路 选择变压器，如果可能的话，我们需要意识到其励磁电流规格并选择具有最小的磁化电流。在我的设计中我使用内置变压器一种廉价2VA热熔断体和20mA的励磁电流。由于电池充电器（变压器TR1和LM317稳压器）只工作1-2分钟，而每小时的优化并没有尝试。安装上文所述的恒温系统的设计是沿电源线安装提供交流电源的冰箱。而冰箱的修改是必要的。其中密封热敏电阻，在薄薄的焊接电缆结束足够的长度，需要将插入冰箱内部。这是最好地实现使用冰箱排水。 而温度传感器的位置很重要。如果热敏电阻是靠
9、近左边冰箱内部的冰柜底部，温控器将控制在最低冰箱温度。如果热敏电阻靠近车厢顶部冷却，恒温器将控制那里的最高温度。最实用的热敏电阻的位置在某处的中间。在我设计的冰箱内热敏电阻是支持在所需位置室内地板以上的冰箱使用的聚乙烯管件于一体。温度传感器支持这种方法来进行测量冰箱内部的空气，而不是冰箱温度的金属墙。图3 组装图 温度测量 我可以忽略了温度测量和现实自我温控器为了保持实际的简单设计可能性。帮助我做出这个决定的是市场上的温度测量装置。我个人使用“双温度计”，其“远程”温度传感器与硅胶密封。它的措施为2种显示温度：冰箱里面的一个温度和冰箱外空间的一个。薄弱环节温控器在设计上面有一个薄弱环节。当主电
10、源（220 - 240V）不可用，冰箱内部温度上升，60mAh电池电源继电器线圈注册要消耗3-4小时，然后将走平。使用更大容量的电池可以延长本时间。 我注意着这个问题，因为如果停电了好几个小时，冰箱的任何环节，无论多么先进的，都需要一个非常仔细的检查和人工干预。当电源恢复后，我的系统将需要转换“注册SW1的”模式为一天左右，使电池变得完全无用。原文：ENERGY EFFICIENT REFRIGERATIONBy Dr Tom Chalko, MSc, PhDMt Best, Australia, Abstract: This article describes a household ref
11、rigerator that requires about 0.1 kWh per dayto operate. The refrigerator offers excellent food-preserving performance, because temperature fluctuations in its interior are naturally minimized during everyday use. This fridge is 10 to 20 times more energy efficient than typical household fridges on
12、the market today. It seems that the biggest obstacles in increasing the energy efficiency and foodpreserving performance of household refrigerators are strange human habits and lack of understanding of Nature, not technology or cost.Chest fridge Comparing the daily energy consumption of various refr
13、igeration devices available on themarket reveals that well-designed chest freezers consume less electricity per day than refrigerators of comparable volume, even though freezers maintain much larger interior-exterior temperature difference (their interiors are much cooler). While chest freezers typi
14、cally have better thermal insulation and larger evaporators than fridges, there is another important reason for their efficiency. Vertical doors in refrigeration devices are inherently inefficient. As soon as we open a vertical fridge door the cold air escapes, simply because it is heavier than the
15、warmer air in the room. When we open a chest freezer the cool air stays inside, just because its heavy. Any leak or wear in a vertical door seal (no seal is perfect) causes significant loss of refrigerator efficiency. In contrast, even if we leave the chest freezer door wide open, the heavy cool air
16、 will still remain inside. Designing and marketing refrigeration devices with vertical doors is clearly an act against theNature of Cold Air. Shouldnt we cooperate with Nature rather than work against it?In 2004 I became really curious just how efficient a “chest fridge” can be. After contacting som
17、e leading fridge manufacturers and discovering they never made and tested a concept of a chest fridge, I decided to make my own test. I bought a well-designed chest freezer (Vestfrost SE255 chest freezer with 600a refrigerant) and converted it into a fridge. Converting chest freezer into fridge The
18、main difference between a freezer and a fridge is the temperature maintained inside. Freezers maintain sub-zero (freezing) temperatures down to 25o C, while fridges operate somewhere between +4o and +10o C. Hence, turning a freezer into a fridge means changing the temperature control. Rather thanint
19、erfering with the thermostat of the freezer, I decided to install an external thermostat to cut the power off when the temperature of my choice is reached. The block diagram in Fig 1 illustrates the idea. Connection diagram (Fig 1) is really simple. Thermostat relay cuts the power to the freezer. Th
20、ermistor (the temperature sensor) is placed inside the freezer at the end of a thin 2-wire flexible cable. I used the freezer drain hole to pass the thermistor cable inside the coolingcompartment. I have also removed the fridge interior light bulb, rated 15 Watts, because I avoid wasting energy as a
21、 matter of principle. I may consider installing a LED interior illumination if I find a reason for opening my fridge in the dark.Thermostat design Although, in essence, the thermostat function is very simple, design of a really good freezer-tofridge thermostat system is not quite trivial. There are
22、some unexpected problems and challenges that only become apparent when one aims to design a system that meets all required criteria and works really well.Thermostat requirements 1. Reliability. Fridges need to be very reliable household devices, simply because our healthdepends on their reliability.
23、 Excessive temperature fluctuations due to any malfunctioning of the thermostat accelerate food spoilage and introduce the associated health risks. The thermostat should work unattended for years if not for decades. 2. Safety. The 240V power supply to the fridge should be well insulated from all low
24、-voltageelectronic components of the thermostat. 3. Zero mains (240V) power consumption during the standby period (when the fridge compressor is off). This requirement is critical in the situation when a modern inverter with a power-demand-sensing feature powers the fridge (in the case of a solar-po
25、wered chest fridge). Using zerostandby- power appliances allows inverter users to save up to 0.4 kWh per day just byallowing the inverter to enter the low-powerconsumption standby (sleep) mode at every opportunity. Inverter-based energy savings of up to 0.4 kWh/day need to be considered in the conte
26、xt of the daily energy consumption of the chest fridge of 0.1 kWh. The zerostandby power requirement turned out to be the greatest challenge in the practical thermostat design. 4. Hysteresis. The number of fridge compressor starts per hour should be kept low, not only to conserve energy, but also to
27、 minimize the compressor wear. 5. The thermostat should be easy to install and should not require any modifications to any freezer, so that a new freezer warranty is not compromised in any way.6. The thermostat should be simple and easy to construct from readily available low cost componentsThe desi
28、gn The schematic of the system that I currently use is depicted in Fig 2. It is a result of a compromise between the minimal possible power consumption, simplicity and the cost of components. The temperature sensing system consists of thermistor R1 (BC 2322 640 54103, 10k 25C) interfaced with an op-
29、amp. The LM324 quad op-amp that I selected has quite low power consumption (0.7 mA) and can operate from single voltage power supply, which greatly simplifies the design. U1C and U1D serve as buffers, to minimize the power consumption taken by the temperaturemeasurement and comparison system down to
30、 negligible values. U1B is a summing amplifier. U1A is a Schmidt trigger with easy to adjust hysteresis (by changing R13), set here at approximately 0.5C. Capacitor C4 prevents radio signals that may appear on the long thermistor R1 cable from interfering with functioning of the system. The switch S
31、W1 addresses the issue of powering the system down (the center-off position) and allows the thermostat to operate in two modes: powered by mains 240V (“SW1 up”, in whichcase the battery can be removed) and from the battery (“SW1 down”, the zero-standby-power mode). The “SW1 up” mode also addresses t
32、he issue of the initial charging of the battery. Note the use of the micro-power LM2936 as a 5V regulator. Typically used LM7805 would by itself consume 5 times more power than the entire circuit and would prevent the entire system to become classified as micro-power. Using LM7805 would make battery
33、 discharge cycles 5 times deeper and hence requiring 5 times larger capacity battery for sustained operation, not to mention a larger transformer to keep the battery charged. In “SW1 down” mode, the battery is charged when the freezer relay and the compressor are on, which, for my Vestfrost fridge,
34、is between 1 and 2 minutes per hour. The rest of the time, the thermistor circuitry is powered up by the battery, and it does not draw any current from the 240Vmains supply.During the system operation, the nominal 8.4V NiMh battery voltage varies between 9.2V and 9.4V, so that in practical terms the
35、 battery remains fully charged and hence can operate for many years. When choosing the transformer, we need to be aware of its magnetizing current specificationsand choose the one with the minimum magnetizing current, if possible. In my design I used an inexpensive 2VA transformer with builtin therm
36、al fuse and the magnetizing current 20mA. Since the battery charger section (transformer TR1 and LM317 regulator) only work 1-2 minutes perhour, their optimization was not attempted.Installation The thermostat system described above is designed to be installed along a power cable that delivers AC po
37、wer to the freezer. No freezer modification is needed. The well-sealed thermistor, soldered at the end of a thin cable of sufficient length, needs to be inserted into the freezer interior. This is best achieved using a freezer-draining hole. The location of the temperature sensor is important. If th
38、e thermistor is left near the bottom of the chest fridge interior the thermostat will control the minimum fridge temperature. If the thermistor is located near the top of the cooling compartment the thermostat will control the maximum temperature there. The most practical position for the thermistor
39、 is somewhere in the middle. In my fridge the thermistor is supported at the desired location above the fridge interior floorusing a piece of a polyethylene tube held in one of the corners. The temperature sensor supported this way measures the temperature of the air inside the fridge interior, rath
40、er than the temperature of the metal wall.Temperature measurement I have deliberately omitted temperature measuring and display from my thermostat design in order to keep the design as simple as possible. What helped me in this decision was an abundance of the temperature measuring devices available
41、 on the market. Personally I use a “dual thermometer” with its “remote” temperature sensor well sealed with silicone. It measures and displays 2 temperatures: one inside the fridge and one in the room outside it.The weak point The thermostat design above has one weak point. When the mains power (220
42、-240V) is not available and the fridge interior temperature rises, the 60mAh battery will power the relay coil up for a 3-4 hours and then will go flat. Using a larger capacity battery can extend this time. I have doubts if this issue requires attention, because if the power goes down for many hours,the content of any fridge, no matter how advanced, will need a very careful inspection and manual intervention. When the power is restored, my system will require switching to the “SW1 up” mode for a day or so, so that the battery becomes fully charged.
