论文总字数：22538字

摘 要

空气湿度过大不仅影响人的健康,还影响工农业生产和产品的储存。我国大部分地区夏季室外空气相对湿度超过70 % ,因此需要采取有效的措施来保证空气的湿度符合要求。制冷除湿是目前空调系统中应用最为广泛的一种除湿方法,它是指利用冷却方法使空气温度降低到露点以下,使水蒸气凝结析出,从而降低空气含湿量的方法。目前，空气除湿主要有四种方法，即通风除湿、冷却除湿、液体吸湿剂除湿和固体吸附剂除湿。在空调除湿工程中，冷却除湿和固体吸附除湿是主要手段。冷却除湿在一般条件下除湿效果好，性能稳定且能耗较低，目前应用比较广泛。

本课题研究的是除湿机的设计，采用冷冻除湿的原理，用制冷机作为冷源，以直接蒸发式冷却器作冷却设备，把空气冷却到露点温度以下，析出大于饱和含湿量的水汽，降低空气的绝对含湿量，再利用冷凝热加热冷却后的空气，从而降低空气的相对湿度，从而达到除湿目的。本文中除湿机是串联连接，其主要部件有蒸发器、压缩机、冷凝器等，通过调节水冷冷凝器的冷却水量来调节控制空气的温度。一般除湿机由制冷系统和送风系统组成。其制冷系统中，由压缩机压缩出来的高温高压制冷剂气体进入再热器，将热量传给空气后，冷凝成常温高压液体，经毛细管（膨胀阀）节流后进入蒸发器，吸收通过蒸发器的空气中的热量，变成低温低压气体，被吸入压缩机进行压缩，如此往复循环。而对于送风系统，湿空气被吸入后，在蒸发器被冷却到露点温度以下，析出冷凝水，绝对含湿量下降，再进入再热器，吸收制冷剂的热量而升温，相对湿度降低，由送风机送入房间。冷冻除湿机用机组的部分冷凝热来提高机组的出风温度，虽可节省电加热的耗电量，但仍存在着制冷量和加热量相互抵消的问题，将热管技术运用于冷冻除湿机，用热管换热器回收蒸发器出口空气的冷量，既能节省电加热的耗电，防止冷热抵消，又能提高出风温度。

本文研究的是40kg/h风道除湿机设计，即制冷量为40kg/h。其设计的主要内容是单级压缩制冷循环中蒸发器和冷凝器的设计，包括蒸发器，冷凝器的设计以及压缩机的选型，运用了工程热力学、传热学、流体力学、制冷技术及相关技术

专业课程的知识。根据制冷循环确定进出口温度，结合压缩机的功率和排气量选择压缩机；通过热力计算和换热器的结构设计计算确定蒸发器和冷凝器的结构，排管布置。

通过本课题的研究，可以看到冷冻除湿机具有除湿效果好、房间相对湿度下降快等优点，广泛应用于各个场所，对我国的经济社会环境具有重要意义，具有良好的应用前景。

关键词：除湿机设计 蒸发器 冷凝器 压缩机

The design 40kg/h dehumidifier

Abstract

The large humidity air not only affect people's health, but also affect industrial and agricultural production and storage of the product. Most our summer outdoor air relative humidity exceeds 70%, so it is important to take effective measures to ensure that the humidity of the air to meet the requirements. Cooling dehumidification is a kind of air dehumidification method which is currently the most widely used in the air conditioning system, and it refers to that the air is cooled to below the dew point of the air temperature, precipitated out condensation water, declined the absolute moisture content. There are four ways of air dehumidification that the ventilation dehumidification,cooling dehumidification,liquid hygroscopic agent dehumidification and solid adsorbent dehumidification. Cooling dehumidification and solid desiccant are the principal means in air conditioning dehumidification engineering. Cooling dehumidification under normal conditions have a good dehumidification effect, stable performance and low energy consumption, so used widely.

A kind of dehumidifier is designed in this paper. Frozen dehumidifier is designed according to the principle of frozen dehumidification, using chillers as the old source and the direct evaporative cooler as cooling equipment .When a ir is cooled to the temperature below dew point ,the part of water vapor which is more than the saturated moisture content will be separated out, reducing the absolute moisture content of the air .Then use the condensation heat to heat the cooled air .After that the relative humidity of air will be reduced, achieving the purpose of dehumidification . Its main components are the evaporator, compressor, condenser, etc , by adjusting the amount of cooling water of condenser to control the air temperature. Dehumidifier system includes two parts: refrigeration system and air supply system. In the refrigeration system ,high temperature and high pressure refrigerant gas is compressed from the compressor into the condenser. After it transfers heat the air , the refrigerant gas will become a kind of high-pressure liquid with the room temperature. Absorbed by the heat in the evaporator of the air into the low-temperature low-pressure gas into the evaporator through the expansion value throttle, which be sucked into the compressor for compression , then repeated cycle. The air supply system performances when the wet air is inhaled. The evaporator is cooled below the dew point temperature ,precipitation of moist air condensing water ,then air absolute moisture content is decreased ,and then into the condenser, absorb the heat of the refrigerant leaving air temperature rise, the relative humidity decreased by the blower send into the room. The units part of the condensing heat in frozen dehumidifier or thermostat dehumidifier (using two condensers) is used to improve the temperature of the air. While it can save the power consumption of the electric heating, there are still the offsets between the heat and cooling capacity. Heat pipe technology can be applied to the dehumidifier aiming that the cooling capacity of the evaporator outlet air can be absorbed by the heat transfer. This can not only save the power consumption of the electric heating, prevent the hot and cold counteract, but also increase the air temperature.

It is described the design of 40 dehumidifier in this paper, this dehumidifier’s capacity is 40kg/h, its main content of this design is a single-stage compression refrigeration cycle with evaporator and condenser design including the evaporator, the design of condenser and compressor selection with the knowledge of engineering thermodynamics, heat transfer, fluid mechanics, refrigeration technology and related professional courses. According to the refrigeration cycle to determine the inlet and outlet air temperatures, combined with the power and displacement of the compressor to select a compressor. It is used to determine the structure of the evaporator and condenser as well as pipe arrangement by the thermodynamic calculation and the structural calculation of the heat exchanger.

Through the research of this subject, we see the frozen dehumidifier has many advantages like dehumidification, fastly decreasing room relative humidity ,etc. Dehumidifier is widely used in warious places. It has important meanings to economy

and social environment in China，which has good application prospect.

Key words: dehumidifier design ; evaporator; condenser; compressor

目录

摘要 I

Abstract III

第一章 前言 1

第二章 除湿机的简介 2

2.1 课题背景 2

2.2 除湿机简介 3

2.3 冷冻除湿机的基本原理 3

2.4 空气除湿的方法 4

2.5 除湿机的分类 4

2.6 制冷除湿的特点 6

2.7本课题研究内容 7

第三章 设计计算说明书 8

3.1已知数据参数 8

3.2湿空气的计算 8

3.3单级压缩机制冷循环的计算 9

3.4压缩机的选型 11

3.5确定最佳风量 11

3.6蒸发器设计计算 12

3.6.1确定蒸发器进、出口空气参数 12

3.6.2确定蒸发器的结构参数 13

3.6.3蒸发器的设计计算 13

3.6.4特性参数汇总如下表所示 25

3.7冷凝器的设计 25

3.7.1冷凝器的结构参数 25

3.7.2冷凝器传热计算 29

3.7.3冷凝器结构尺寸的计算 32

3.7.4特性参数汇总表如下 33

结束语 34

参考文献 35

致谢 37

第一章 前言

生产和生活环境中，空气的相对湿度具有举足轻重的影响。对湿度的控制和调节，是关系到工农业生产工艺流程、物质储存保管的重要问题^[1]。相对湿度过高，机器设备和钢铁产品易于腐蚀、食品易于腐烂，将会给生产、生活及物资储存造成巨大损失。因此，随着工艺水平及要求的提高，空气除湿等环境控制技术的发展显得尤为重要 ^[2]。空气除湿一般以冷却除湿为主，冷却除湿以其在一般条件下除湿效果好性能稳定且除湿效率高等优点得到了广泛的应用^[3]。冷却除湿机具有除湿效果好、房间相对湿度下降快、运行费用低、不要求热源、也可不需要冷却水、操作方便、使用灵活等优点，被广泛应用于国防工程、人防工程、各类仓库、图书馆、档案馆、地下工程、电子工业、精密机械加工、医药、食品、农业种子储藏及各工矿企业车间等场所^[4]。

请支付后下载全文，论文总字数：22538字