2016建环专业英语文献翻译.docx

Mechanical Dehumidifiers and Related Components24.35英语文献翻译专业：12级建环1班 学号：20120110070121姓名：董化栋 指导老师：李建强 CHAPTER 24MECHANICAL DEHUMIDIFIERS AND RELATED COMPONENTSMechanical Dehumidifiers24.1Installation and Service Considerations 24.7Wraparound Heat Exchangers24.7第24章机械除湿机和相关组件机械除湿机安装和服务注意事项环绕式热交换器Licensed for single user. 2008 ASHRAE, Inc.THE correct moisture level in the air is important for health and comfort. Controlling humidity and condensation is important to prevent moisture damage and mold or mildew development, thus protecting buildings and occupants, and preserving building con-tents. This chapter covers mechanical dehumidification using a cooling process only, including basic dehumidifier models (with moisture removal capacity of less than 1.4 kg/h) used for home basements and small storage areas, as well as larger sizes required for commercial applications. Other methods of dehumidification are covered in Chapter 23.Commercial applications for mechanical dehumidifiers include the following:Indoor swimming pools Makeup air treatment Ice rinks Dry storage Schools Hospitals Office buildings Museums, libraries, and archives Restaurants Hotels and motels Assisted living facilities SupermarketsManufacturing plants and processesIn addition, an air-to-air heat exchanger (such as a heat pipe, coil runaround loop, fixed-plate heat exchanger, or rotary heat exchanger) may be used to enhance moisture removal by a mechan-ical dehumidifier or air conditioner. The section on Wraparound Heat Exchangers discusses how dehumidification processes can be improved by using such a device. Other uses of air-to-air heat exchangers are covered in Chapter 25.空气中正确的湿度对健康和舒适度而言是很重要的。为了保护建筑物和居住者和要建筑物内的物品，关键是通过控制湿度及冷凝度来防止湿气损坏或霉坏物品，和阻止霉菌的生长。本章涵盖了机械除湿使用冷却过程,包括基本的除湿机模型(除去水分的能力小于1.4 kg / h)用于家里地下室和小的存储区域,以及更大尺寸的商业应用要求。其他除湿方法则在23章中提及。商业应用机械除湿机包括以下:室内游泳池化妆空气处理溜冰场干仓学校医院办公场所博物馆、图书馆和档案馆餐馆酒店和汽车旅馆辅助生活设施超市制造工厂和生产过程此外，空气 - 空气热交换器（例如，热管，线圈操作现场环，固定板式换热器，或旋转热交换器），可以使用通过机械除湿或空调，以提高除去水分。上环绕式换热器的节讨论如何除湿过程可以通过使用这样的装置来改善。空气 - 空气热交换器的其它用途包括在第25章。MECHANICAL DEHUMIDIFIERS机械除湿机Mechanical dehumidifiers remove moisture by passing air over a surface that has been cooled below the airs dew point. This cold sur-face may be the exterior of a chilled-water coil or a direct-expansion refrigerant coil. To prevent overcooling the space (and avoid the need to add heat energy from another source), a mechanical dehumidifier also usually has means to reheat the air, normally using recovered and recycled energy (e.g., recovering heat from hot refrigerant vapor in the refrigeration circuit). Using external energy input for reheat is wasteful and is prohibited or limited in many countries (see ASHRAE Standard 90.1).机械除湿通过使空气通过已经冷却的空气的露点以下的表面除去水分。这个冷的表面可以是冷冻水盘管或直膨致冷剂线圈的外部。为了防止空间的过冷（并避免需要从另一源添加热能），机械除湿也通常具有再加热空气的装置，通常使用回收并再循环能量（例如，在制冷回路中回收热的制冷剂蒸气的热）。使用外部能量输入的再加热是一种浪费，并在很多国家是禁止或者限制（见ASHRAE标准90.1）。A mechanical dehumidifier differs from a typical off-the-shelf air conditioner in that the dehumidifier usually has a much lower sensible heat ratio (SHR). The dehumidifier starts the compressor on a call for dehumidification, whereas an air conditioner starts the compressor on a call for sensible cooling. Typically, a room dehumidifier has an SHR of 0.6 or less, compared to a standard air-conditioning system of 0.8 SHR. Dehumidifiers must also allow condensation from the cooling coil to drain easily from the coils. They may need air velocities over the cooling coil lower than those for a typical air conditioner, to improve moisture runoff and mini-mize carryover of condensed moisture.一个机械除湿从典型的现成的，货架空调器的不同在于，除湿器通常具有低得多的显热比（SHR）。除湿机开始通话除湿压缩机，而一台空调就开始呼吁显冷压缩机。通常情况下，一个房间除湿具有0.6或更小的SHR，相比0.8 SHR的标准空调系统。除湿机还必须允许从冷却盘管冷凝来自线圈容易排出。他们可能需要的气流速度过冷却盘管低于那些典型的空调，以提高水分流失和减少凝结的水分的残留。In addition, the need to introduce code-mandated ventilation air may require that outside air be treated to avoid introducing excessive moisture. Basic strategies include precooling outside air entering the air-conditioning evaporator coil, or providing a separate system to provide properly conditioned outside air. For some low- dew-point (below 7) applications, mechanical dehumidification may be used as the first stage, with desiccant dehumidification for the final stage to maximize efficiency and minimize installed cost.此外，需要引入规范强制通风的空气，可能需要处理室外空气，以避免引入过多的水分。基本策略包括预冷的外部空气进入空调蒸发器线圈，或提供一个单独的系统提供适当条件的室外空气。对于一些低露点（7以下）的应用，机械除湿可以作为第一阶段，以除湿为最大限度地提高效率并减少安装成本的最后阶段。Although the main purpose of a mechanical dehumidifier is to remove moisture from the air, many features can be incorporated for various applications, such as Dehumidifying and cooling (no reheat) Dehumidifying with partial reheat (leaving dry-bulb temperature is cooler than with a dehumidifier with full reheat) Dehumidifying with full reheat Dehumidifying with heat recovery to various heat sinks Dehumidification capacity modulation Reheat capacity modulation Ventilation air introduction Auxiliary space or water heatingOften, mechanical dehumidifiers can be incorporated in a system to use waste heat from mechanical cooling (e.g., heat rejection to a swimming pool, whirlpool, domestic hot water, heat pump loop, chilled-water loop, or remote air-cooled condenser).虽然机械除湿机的主要目的是除去空气中的水分，但是仍存在许多可以合并的功能的应用，如除湿降温（不加热）除湿部分再热（剩下的干球温度是一个充分的加热除湿机冷却器）充分的加热除湿除湿热回收各种散热器除湿量调制再热调节容量通风空气引入辅助空间或水加热通常情况下，机械除湿机可以在一个系统中整合使用废热机械冷却（例如，散热的游泳池，浴池，生活热水，热泵循环冷冻水环，或远程风冷式冷凝器）。Outdoor dehumidifiers should be protected against internal mois-ture condensation when winter conditions are severe, because of the higher dew-point temperature of air circulating in the unit.室外机应防止内部水分凝结在冬天的情况很严重，因为在循环的单位空气露点温度更高。Psychrometrics of Dehumidification除湿空气线图Air enters the dehumidifying coil at point A (Figures 1 and 2). The dehumidifying coil removes sensible heat (SH) and latent heat (LH) from the airstream. The dehumidified, cooled air leaves the coil at its saturation temperature at point B. The total heat removed (TH) is the net cooling capacity of the system.空气在A点进入除湿盘管（图1和图2）。除湿盘管去除显热（SH）和潜热（LH）从气流。除湿后的冷空气，在B点的总热除去它的饱和温度离开线圈（TH）是系统的净制冷量。In reheating, the hot gas rejects heat from three sources. First, sensible heat absorbed in the air-cooling process is rejected to air leaving the cooling coil. This air is at point C, which is the same dry- bulb temperature as the entering air minus the moisture content. Second, the latent heat removal that causes the moisture to condense also adds heat to the hot refrigerant gas. This heat is also rejected into the airstream, raising the air temperature to point D. Third, nearly all electric power required to drive the refrigeration cycle is converted to heat. This portion of heat rejection raises the air leaving temperature to point E.在再加热，热气体从三个来源排斥热量。首先，在空气冷却过程吸收显热被排斥到空气离开冷却线圈。该空气是在点C处，这是相同的干法球温度为进入的空气减去含水量。第二，该潜热去除导致的水分冷凝也增加热量使热的制冷剂气体。这个热量也被排斥进入气流，提高空气温度到点D.第三，几乎都以驱动制冷循环所需的电功率被转换成热。排热的这一部分提出了一个空气离开温度为指向E.Fig. 1 Dehumidification Process PointskJ PER KILOGRAM OF DRY AIRFig. 2 Psychrometric Diagram of Typical Dehumidification ProcessLicensed for single user. 2008 ASHRAE, Inc.This process assumes that all heat is rejected by the reheat coil. Depending on the refrigerant system complexity, any part of the total heat rejection can be diverted to other heat exchangers (con- densers/desuperheaters).这一过程假设所有热量由再热盘管拒绝。根据制冷系统的复杂性，总的排热的任何部分可以被转移到其它热交换器（冷凝器/减温器）。Dehumidifier supply air temperatures can be controlled between 10 and 35. However, system design should not rely on a mechanical dehumidifier as a dependable heat source for space heating, because heat is only available when the unit is operating.除湿机送风温度可在10至35之间的控制。然而，制度设计不应该依赖于机械除湿机作为采暖可靠的热源，因为热量只有当本机工作使用。Domestic Dehumidifiers家用除湿机Domestic dehumidifiers are smaller (usually less than 3.5 kW), simpler versions of commercial dehumidifiers. They are self- contained and easily movable.家用除湿机更小(通常小于3.5 kW),商业除湿机的简单版本。他们是自我包含的,便携的。As shown in Figure 3, a single fan draws humid room air through the cold coil, removing moisture that either drains into the water receptacle or passes through the cabinet into some other means of disposal. The cooled air passes through the condenser, reheating the air.如图3所示，一个单一的风机通过冷卷将潮湿的房间空气抽成潮湿的房间空气，除去湿气进入水容器中，或者通过机柜进入另一些处理装置的装置中。冷却的空气通过冷凝器，加热空气。Domestic dehumidifiers ordinarily maintain satisfactory humidity levels in an enclosed space when the airflow rate and unit placement move the entire air volume of the space through the dehumidifier once an hour.家用除湿机通常保持在一个封闭的空间，良好的湿度水平，当气流速度和单位安置将整个空间的空气量通过除湿机每小时一次。Design and Construction. Domestic dehumidifiers use hermetic motor-compressors; the refrigerant condenser is usually conven-tional finned tube. Refrigerant flow is usually controlled by a capillary tube, although some high-capacity dehumidifiers use an expansion valve. A propeller fan moves air through the unit at typical airflows of 70 to 120 L/s.设计与施工。家用除湿机使用密封式电动压缩机；制冷剂冷凝器通常是传统的翅片管。虽然制冷剂流量通常是由毛细管控制，但是一些大容量除湿机使用膨胀阀。螺旋桨式风机将空气通过的气流单元在70-120L/S。The refrigerated surface (evaporator) is usually a bare-tube coil, although finned-tube coils can be used if they are spaced to allow rapid runoff of water droplets. Vertically disposed bare-tube coilstend to collect smaller drops of water, promote quicker runoff, and cause less water reevaporation than finned-tube or horizontally arranged bare-tube coils. Continuous bare-tube coils, wound in a flat circular spiral (sometimes with two coil layers) and mounted with the flat dimension of the coil in the vertical plane, are a good design compromise because they have most of the advantages of the vertical bare-tube coil.冷藏表面（蒸发器）通常是一个裸管线圈，虽然翅片管线圈可以使用，如果它们是间隔，以允许快速径流的水滴。垂直布置的光管的线圈将收集小水滴，促进更快的径流，并使翅片管或水平布置的裸管圈水少再蒸发。连续裸管线圈，绕在一个平面圆形螺旋线圈（有时有2个线圈层）和安装在垂直平面线圈的平面尺寸，是一个很好的设计折衷，因为他们有最优点的垂直裸管线圈。Evaporators are protected against corrosion by finishes such as waxing, painting, or anodizing (on aluminum). Waxing reduces the wetting effect that promotes condensate formation; however, tests on waxed versus nonwaxed evaporator surfaces show negligible loss of capacity. Thin paint films do not have an appreciable effect on capacity.蒸发器的防腐蚀保护的完成如打蜡，绘画，或阳极氧化（铝）。打蜡减少润湿效应促进凝结形成；然而，测试就与不上蜡的蒸发器表面容量损失可以忽略不计。薄膜没有明显的影响能力。Removable water receptacles, provided with most dehumidifiers, hold 7.5 to 11 L and are usually made of plastic to withstand corrosion. Easy removal and handling without spillage are important. Most dehumidifiers also provide either a means of attaching a flexible hose to the water receptacle or a fitting provided specially for that purpose, allowing direct gravity drainage to another means of disposal external to the cabinet.可拆卸水贮器，设置有多数的除湿机，保持7.5至11 L和通常由塑料制成以承受腐蚀。方便拆卸和处理不泄漏是很重要的。最除湿机还提供任一柔性软管附接到水容器或用于该目的专门提供的嵌合，允许直接重力排水至外部的机壳处置的另一装置的装置。More expensive dehumidifiers usually have higher output capacities, are more attractively styled, and have various auxiliary features. An adjustable humidistat (30 to 80%) automatically cycles the unit to maintain a preselected relative humidity. The humidistat may also provide a detent setting for continuous operation. Some models also include a sensing and switching device that automatically turns the unit off when the water receptacle is full.更昂贵的除湿机通常有更高的输出能力，更迷人的风格，并有多种辅助功能。可调湿度（3080%）自动循环装置保持预定的相对湿度。的湿度也可以提供定位连续运行设置。一些模型还包括一个传感和开关装置，当水的容器被充分的时候自动关闭该单元。Dehumidifiers are designed to provide optimum performance at standard rating conditions of 27 db room temperature and 60% rh. When the room is less than 18 db and 60% rh, the evaporator may freeze. This effect is especially noticeable on units with a capillary tube.除湿机的目的是提供在27分贝室温和60RH的标准额定条件最佳性能。当房间小于18分贝和60RH，蒸发器可能会冻结。这种效果是在具有毛细管单元尤其明显。Some dehumidifiers are equipped with defrost controls that cycle the compressor off under frosting conditions. This control is generally a bimetal thermostat attached to the evaporator tubing, allowing dehumidification to continue at a reduced rate when frosting conditions exist. The humidistat can sometimes be adjusted to a higher relative humidity setting, which reduces the number and duration of running cycles and allows satisfactory operation at low-load conditions. Often, especially in the late fall and early spring, supplemental heat must be provided from other sources to maintain above-frosting temperatures in the space.一些除湿机都配有控制循环压缩机结霜除霜了。这种控制通常是一个双金属温控器安装在蒸发器管，使除湿继续在降低利率时，结霜条件存在。的湿度有时会调整到一个更高的相对湿度的设定，从而减少运行次数和持续时间，使令人满意的运行在低负荷条件下。通常，尤其是在晚秋和早春，补充热量，必须从其他来源提供的保持温度在空间上结霜。Capacity and Performance Rating. Domestic dehumidifiers are available with moisture removal capacities of 5 to 30 L per 24 h, and are operable from ordinary household electrical outlets (115 orLicensed for single user. 2008 ASHRAE, Inc.230 V, single-phase, 60 Hz). Input varies from 200 to 800 W, depending on the output capacity rating.AHAM Standard DH-1 establishes a uniform procedure for determining the rated capacity of dehumidifiers under specified test conditions and also establishes other recommended performance characteristics. An industry certification program sponsored by AHAM covers the great majority of domestic dehumidifiers and certifies dehumidification capacity.容量和性能评价。家用除湿机有5水分的去除能力30升每24 h，并从普通家用电源插座操作（115或230伏，单相，60 Hz）。输入的变化从200到800瓦，取决于输出容量额定值。AHAM标准DH-1建立指定的测试条件下，除湿机的额定容量，确定统一的程序建立了其他推荐的性能特点。一个行业的认证程序由AHAM涵盖绝大多数国内除湿机除湿能力和认证。The U.S. Environmental Protection Agency (EPA) qualifies dehumidifiers to carry its ENERGY STAR?label if they remove the same amount of moisture as similarly sized standard units, but use at least 10% less energy. The EPA抯 ENERGY STAR web site provides additional information on qualifying products (EPA 2008).美国环境保护署（EPA）使除湿机进行了能源之星？标签如果他们删除相同数量的水分同样大小的标准单位，但至少使用10%以下的能量。抯EPA的能源之星网站提供了额外的信息，对合格产品（EPA 2008）。Codes. Domestic dehumidifiers are designed to meet the safety requirements of UL Standard 474, Canadian Electrical Code, and ASHRAE Standard 15. UL-listed and CSA-approved equipment have a label or data plate indicating approval. UL also publishes the Electrical Appliance and Utilization Equipment Directory, which covers this type of appliance.代码。家用除湿机的设计是为了满足UL 474标准的安全要求，电气规程，和ASHRAE标准15。UL和CSA认可的设备有一个标签或铭牌指示批准。UL还出版的电气设备和用电设备目录，其中涵盖这类电器。General-Purpose Dehumidifiers通用除湿机Basic components of general-purpose dehumidifiers are shown in Figure 4. An air filter is required to protect the evaporator. Dehumidifying coils, because of their depth and thoroughly wetted surfaces, are excellent dust collectors and not as easily cleanable as much thinner air-conditioning evaporator coils. However, the large amount of condensate has a self-cleaning effect. The bypass damper above the evaporator coil allows airflow adjustments for the evaporator without decreasing airflow for the reheat coil. Dehumidifying and reheat coils perform best at different airflows.通用除湿机的基本组成如图4所示。为了保护蒸发器，需要一个空气过滤器。除湿盘管，因为他们的深度和彻底润湿表面，是优良的除尘器和不易清洗的多薄空调蒸发器盘管。然而，凝析油大量具有自洁作用。旁路挡板的上方蒸发器线圈使气流调整为蒸发器不降低再热盘管的气流。除湿再热盘管执行在不同的气流。The compressor may be isolated from the airstream or located in it. Locating the compressor in the airstream may make service more difficult, but this arrangement allows heat lost through the compressor casing to be provided to the conditioned space while reducing the size of the enclosure. During the cooling season, this compressor location reduces the units sensible cooling capacity.压缩机可以在它从气流中分离或定位。在气流中定位压缩机可使服务更加困难，但这种安排使得热量通过压缩机外壳应同时降低外壳的大小来调节空间提供了。在冷却季节，该压缩机的位置降低了机组的显冷能力。Code-required ventilation air may be introduced between the evaporator and reheat coil. The amount of makeup air should be controlled to not adversely affect the refrigeration systems opera-tion. Preheating ventilation air may be required in colder climates.代码需要通风可以引入之间的蒸发器和再加热盘管。对制冷系统的操作不产生不利影响的化妆空气量。在寒冷的气候条件下可能需要预热通风空气Computerized controls can sense return air temperature and relative humidity. Remote wall-mounted sensors are also available. More sophisticated controls are desirable to regulate dew-point temperature and maintain the desired relative humidity in the space.计算机控制可以感觉到空气温度和相对湿度。远程安装传感器也可提供。更先进的控制是可取的调节露点温度和保持在空间中所需的相对湿度。General Considerations. Before considering installation of any type of dehumidiilcation equipment, all latent loads should be identified and quantified. In many cases, this might lead to decisions that reduce the latent load. For example, a storage facility that does not have an adequate vapor retarder in the building envelope should be retrofitted first before attempting to calculate the amount ofFig. 5 Typical Makeup Air Dehumidifiermoisture migration through the structure. The same approach should be taken to reduce the amount of uncontrolled air infiltration.Consider covering large water surfaces, such as vats, and/or providing a local exhaust hood to evacuate concentrated water vapor from where it is generated. Although these corrections seem to add cost to a project, the resulting reduced size of the dehumidifier and its lower operating cost often result in an attractive financial payback.总的考虑。在考虑任何类型的除湿设备的安装，所有潜在的荷载应确定和量化。在许多情况下，这可能会导致决定，减少潜在的负载。例如，一个储存设施，没有围护结构的适当的蒸气应改造先尝试通过结构计算水分迁移量。同样的做法应该采取减少不受控制的空气渗透量。考虑覆盖大面积的水面，如镜，和/或提供一个局部排风罩将浓水蒸气从哪里产生。虽然这些修正似乎增加的成本项目，从而减少了大小的除湿机，降低运营成本，往往在一个有吸引力的投资回报。Other special considerations include the following: High volumes of makeup air. A project may start out to be suit-able for a general-purpose dehumidifier. However, once makeup air requirements are quantified to compensate for exhaust and to pressurize the facility, a general-purpose dehumidifier may no longer be applicable. The maximum acceptable portion of out-door air for general-purpose dehumidifiers is limited, and depends on climatic conditions and the desired indoor conditions to be maintained. As a general rule, when