2HP热泵干燥机的设计.doc

1、摘要 在工业、农业和食品生产中大量的物料往往需要进行干燥处理，制冷技术在干燥领域的应用主要有两种方法：除湿干燥和冷冻干燥。除湿木材干燥机是实际使用中最常用的一种木材干燥设备，它靠电加热使木材干燥室升温，因此其电能消耗很大。为了减轻能耗，应用热泵来对木材干燥窑进行加热。热泵实质上是一种热量提取装置，高温热泵干燥机组利用逆卡诺原理，从周围环境中吸取热量，并把它传递给被加热的对象，其工作原理与制冷机相同，都是按照逆卡诺循环工作的，所不同的只是工作温度范围不一样。此外，热泵干燥技术除了具有能源消耗之外，还有环境污染小、烘干品质高、适用范围广等优点，其优异的节能效果已被国内外的各种试验研究所证明。 本论

2、文介绍了热泵干燥机的工作原理以及主要组成部件，并且总结了热泵干燥机在节能方面的优势。论文中的热泵干燥机系统采用双冷凝器结构，两个冷凝器的连接可以是串联也可以是并联，本论文设计的热泵干燥机中的冷凝器是属于并联连接，其主要部件有蒸发器，压缩机，冷凝器，风机等。一般干燥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冷凝器，将热量传给空气后，冷凝成常温高压液体，经毛细管节流后进入蒸发器，吸收通过蒸发器的空气中的热量，变成低温低压气体，然后进入压缩机压缩，如此往复循环。而对于送风系统，湿空气被吸入后，在蒸发器中被冷却到露点温度以下，析出冷凝水，此时绝对含湿量下降，然后

3、再进入冷凝器，吸收制冷剂的热量而升温，此时相对湿度又降低，出来后的空气由风机送入干燥室。热泵干燥机用机组的部分冷凝热来提高机组的出风温度，虽可节省用电能加热的耗电量，但仍存在着制冷量和加热量相互抵消的问题，所以我们将热管技术运用于干燥机中，用热管换热器回收蒸发器出口空气的冷量，既能节省电加热的能耗，防止冷热抵消，又能提高出风温度。本论文描述的是一台2HP热泵干燥机的设计，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。根据压缩机功率我们可以算出冷量循环，包括压缩机选型，冷、

4、热负荷计算，风量分配等，然后根据给定条件可以查出空气循环中各点空气状态并进行除湿量的计算，在取得最大除湿量的基础上确定适合的风量分配，最后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，排管布置以及它们的尺寸。 关键词：热泵 干燥机 蒸发器 冷凝器 压缩机IThe design of the heat pump dryerABSTRACT A large number of materials in industry, agriculture and food production often need to be dried. There are two ways of refr

5、igeration technology applications in dry areas, dehumidification drying and freeze drying. The most practical kind of wood drying equipment is called dehumidification wood drying machine. The wood drying kiln is heated by electric , which cost electric energy a lot. To this end, the application of h

6、eat pump heating the wood drying kiln comes to our consideration. The heat pump is essentially a heat lifting device. High temperature heat pump drying units based on reverse Carnot principle, absorb heat from the surrounding environment and pass it to the heated object . This is the same principle

7、with refrigerator based on the reverse Carnot cycle.Their difference is just the operating temperature range. This thesis describes the working principle and the main components of the heat pump dryer, and summarizes the advantages of energy saving. The heat pump dryer system is with dual condenser.

8、 The two condenser connected in series can also be connected in parallel.The heat pump dryer is designed in this thesis are connected in parallel. Its main components are evaporator, compressor, condenser and so on. The general dehumidifier refrigeration systems have two parts, which are air supply

9、systems, and the refrigeration system. The high-temperature high-pressure refrigerant gas is compressed by a compressor into a condenser. The heat passed to the air at room temperature is condensed into high pressure liquid, and then enters to the evaporator after throttling absorbed by capillary tu

10、bes.It becomes the low-temperature and low-pressure gas sucked into the compressor for compression, and so forth cycle. For the blower system, the wet air sucked in the evaporator is cooled below the dew point temperature. The absolute moisture content decreases. And the air re-enters the condenser

11、to absorb the heat of the refrigerant. After that, the relative humidity decreases. At last, the air is blowed into the room. The heat pump dryers outlet air temperature of the unit is increased by part of the heat of condensation unit . It can save electric. But there are still problems of mutually

12、 offset between cooling capacity and processing heat. Heat pipe technology are used in the drying machine to recycle the cooling capacity of the evaporator outlet air with the heat pipe heat exchanger, which can save the power consumption of electric heating to prevent hot and cold offset, but also

13、improve the air temperature. This paper describes the decision of a heat pump dryer. The main point is the designs of evaporator and condenser in a single-stage compression refrigeration cycle, including the designs of evaporator and condenser and the selection of compressor. This design involves th

14、e professional courses of engineering thermodynamics, heat transfer, fluid mechanics, cooling technology and related technical knowledge. According to the compressor power, we can calculate the amount of cold including the compressor selection, cold, heat load calculation, the air volume distributio

15、n. And then calculating the amount of dehumidification and the status of each point of air in the air circulation can be isolated according to the given conditions. By thermodynamic calculation, and structural design of the heat exchanger, the structure of the evaporator and condenser drain pipe ins

16、tallation are determined. Key Words: heat pump; evaporator;condenser; compressorIII目 录摘 要IABSTRACTIII第一章 概述11.1 热泵干燥机简介11.2 热泵干燥机的基本原理11.3 评价干燥机工作效率的主要指标21.4 热泵干燥机的特性21.4.1 热泵干燥机的优点21.4.2 热泵干燥机的缺点21.5 国内外热泵干燥机的一些技术改进与改革3第二章 设计说明书52.1 原始参数52.1.1 压缩机的选型52.1.2 湿空气的计算62.1.3 计算单级压缩制冷循环72.2 蒸发器、冷凝器的设计92.2.1 蒸发器的设计102.2.2 冷凝器的设计142.3 计算结果汇总182.