印刷电路板式换热器采用扩散焊技术，实现金属板材间的高效连接。该技术使换热器结构紧凑，换热效率高，且耐腐蚀、寿命长。在航空航天、电力能源等领域广泛应用，展现了卓越的性能和稳定性。

如图1为采用扩散焊工艺制作的印刷电路板式换热器(PCHE)的截面图。

扩散焊是一种固态焊接方法，通过将工件在高温下加压，使接触面之间的原子相互扩散形成连接。这种焊接方法特别适合异种金属材料、耐热合金、陶瓷、金属间化合物以及复合材料等新材料的接合，尤其是对那些熔焊方法难以焊接的材料，扩散焊展现出明显的优势。

在扩散焊过程中，焊件紧密贴合，然后在一定的温度和压力下保持一段时间。这个过程中，接触面之间的原子会相互扩散，形成冶金连接。焊接温度、压力、扩散时间以及表面粗糙度是影响扩散焊过程和接头质量的主要因素。通常，焊接温度会设定为材料熔点的0.5～0.8倍，以确保原子有足够的能量进行扩散。

扩散焊是在温度和压力的作用下，相互接触的材料表面发生塑性变形，原子间产生相互扩散，在界面处形成新的扩散层，从而实现可靠连接。

Figure 1 shows the cross-section of the printed circuit heat exchanger (PCHE) made by diffusion welding process. The process of diffusion welding is that under the action of temperature and pressure, the surface of the material in contact with each other will undergo plastic deformation, resulting in mutual diffusion between atoms, forming a new diffusion layer at the interface, so as to achieve a reliable connection.

The printed circuit board heat exchanger adopts diffusion welding technology to achieve efficient connection between metal sheets. This technology makes the structure of the heat exchanger compact, with high heat transfer efficiency, corrosion resistance, and long service life. Widely used in aerospace, power energy and other fields, it has demonstrated excellent performance and stability.

图1 印刷电路热交换器(PCHE)的流动截面

Fig 1 Flow cross-section of a printed circuit heat exchanger(PCHE)

图2为采用光蚀刻技术在换热板的冷侧和热侧得到的微通道。

光蚀刻技术，是一种高精度加工技术，特别适用于微通道制造。它通过在光敏树脂上覆盖掩膜，并用紫外线照射，使掩膜上的图案转移到树脂上。随后，将树脂浸泡在蚀刻液中，未被保护的部分会被蚀刻掉，形成所需的微型结构。光蚀刻技术广泛应用于微电子、光电子、生物医学等领域，特别适用于制造具有复杂几何结构或具有许多孔的零件。其优点在于能够制造出高精度、高分辨率的微型结构，并且能加工非常薄的材料，对于超大规模集成电路或纳米材料的制作尤为有效。该技术具有高效、低成本和可重复性好等优点，为微流控芯片、生物医学等领域提供了重要的技术支持。其中所形成的微通道，每个通道由入口、中间段和出口部分组成，均具有半月形截面。

Figure 2 shows the formation of microchannels on the cold and hot sides of the heat exchange plate using photoetching technology. Each channel consists of an entrance, a straight middle and an exit section, all with a half-moon section.Photoetching technology is a high-precision machining technique, particularly suitable for microchannel manufacturing. It utilizes photochemical reactions to form patterns on the surface of materials and accurately characterizes microchannel structures through corrosion. This technology has the advantages of high efficiency, low cost, and good repeatability, providing important technical support for microfluidic chips, biomedical and other fields.

图2平行通道的换热板图片

(A) 热侧板；(B)冷侧板

Fig 2 Picture of heat exchange plate with parallel channel

(A) hot side plate; (B) Cold side panels

图3为印刷电路板式换热器(PCHE)的堆叠层和流动模式的示意图。(A)中设置有3个热侧板和4个冷侧板，(B)中设置有有5个热侧板和6个冷侧板，每个热侧板和冷侧板交替分层。在层状传热板的顶部和底部，与端板焊接加固。

印刷电路板式换热器（PCHE）的堆叠层设计独特，采用了多层堆叠的结构，通过精密的刻蚀工艺，在换热板上刻蚀出换热通道。这些换热板通过扩散焊接技术被巧妙地叠加焊接在一起，形成了一个高效的热交换系统。这种设计不仅提高了换热器的传热效率，还使得整个换热器结构紧凑，便于安装和维护。至于流动模式，PCHE通常采用连续型直流通道的流动模式。这种内部结构设计简单，便于加工，同时流动阻力小，能够有效地提高热交换效率。在这种模式下，冷热流体通过固体区域进行对流换热，实现热量的高效传递。总的来说，印刷电路板式换热器（PCHE）的堆叠层和流动模式都经过了精心的设计和优化，旨在实现高效、可靠的热交换性能。

如图3所示，冷热流体的流动方向为逆流。相比于传统的换热器，它的冷侧流体与热侧流体距离更近，传热效率更高。

Figure 3 is a schematic of the stacked layers and flow patterns of a microchannel printed circuit heat exchanger (PCHE). The heat exchanger in (A) is designed in accordance with 3 hot side plates and 4 cold side plates, and the heat exchanger in (B) is designed in accordance with 5 hot side plates and 6 cold side plates, with each hot side plate and cold side plate alternately layered. The top and bottom of the layered heat transfer plate are welded and reinforced with the end plate.

The stacking layer design of printed circuit board heat exchangers (PCHE) is unique, adopting a multi-layer stacking structure. Through precise etching technology, heat exchange channels are etched on the heat exchange plate. These heat exchange plates are cleverly stacked and welded together through diffusion welding technology, forming an efficient heat exchange system. This design not only improves the heat transfer efficiency of the heat exchanger, but also makes the entire structure of the heat exchanger compact, easy to install and maintain.

As for the flow mode, PCHE usually adopts a continuous DC channel flow mode. This internal structure design is simple, easy to process, and has low flow resistance, which can effectively improve heat exchange efficiency. In this mode, cold and hot fluids undergo convective heat transfer through solid regions, achieving efficient heat transfer.

Overall, the stacking layers and flow patterns of printed circuit board heat exchangers (PCHE) have been carefully designed and optimized to achieve efficient and reliable heat exchange performance.

As shown in Figure 3, the flow direction of hot and cold fluids is countercurrent. Compared with traditional heat exchangers, the distance between the cold side fluid and the hot side fluid is closer, and the heat transfer efficiency is higher.

图3 微通道印刷电路换热器(PCHE)的堆叠层和流动模式

(A) PCHE1(3热/4冷)；(B) PCHE2(5热/6冷)；(C)流程配置

Fig. 3 Stacking layers and flow patterns of microchannel printed circuit heat exchangers (PCHE)

(A) PCHE1(3 hot /4 cold); (B) PCHE2(5 hot /6 cold); (C) Process configuration

印刷电路板式换热器，技术先进，高效节能。其紧凑设计提升传热效率，广泛适用于制冷、空调等领域。现场图展示其精细结构，确保稳定运行。选择我们，体验卓越性能，共创绿色未来！图4为微通道PCHE实物图以及设计图。表1列出了详细的技术参数。

Printed circuit board heat exchanger, advanced technology, efficient and energy-saving. Its compact design enhances heat transfer efficiency and is widely used in fields such as refrigeration and air conditioning. The on-site diagram shows its fine structure to ensure stable operation. Choose us, experience excellent performance, and create a green future together!Figure 4 shows the microchannel PCHE , and Table 1 lists the detailed technical parameters.

图4 印刷电路板式换热器(PCHE)

(A) PCHE的外形图片 (B)设计图纸

Figure 4 Microchannel Printed Circuit Heat Exchanger (PCHE)

(A) Outline pictures of the PCHE (B) design drawings.

表1 印刷电路板式换热器(PCHE)技术参数

Table 1 Technical parameters of microchannel printed circuit heat exchanger (PCHE)

印刷电路板式换热器通道截面图展示了其精细复杂的内部结构。换热通道呈现规则排列，截面形状优化，有效增大换热面积。流体在通道内流动均匀，实现高效热交换。该设计不仅提升了换热效率，还确保了设备的稳定性和耐用性。图5为截取四分之一的PCHE后的通道截面图。其通道为半月形通道。

The cross-sectional view of the channel of the printed circuit board heat exchanger shows its intricate and complex internal structure. The heat exchange channels are arranged in a regular manner, with optimized cross-sectional shapes, effectively increasing the heat exchange area. The fluid flows uniformly in the channel, achieving efficient heat exchange. This design not only improves heat exchange efficiency, but also ensures the stability and durability of the equipment.Figure 5 shows the cross-section of the channel after one-quarter of the PCHE was intercepted. Its channel is a half-moon shaped channel.

图5 印刷电路板式换热器(PCHE)的横截面图

Fig 5 Cross-sectional diagram of a microchannel printed circuit heat exchanger (PCHE)

用于熔盐反应堆测试

For molten salt reactor testing

熔盐反应堆是一种采用溶有易裂变材料且处于熔融状态下的熔盐作为核燃料的反应堆。它的堆芯结构简单，运行过程中可以连续添加燃料和除去产生的裂变产物，从而减少了停堆次数，并可以有效地利用中子。燃料燃耗不受辐射损伤的限    制，使得一座熔盐反应堆生产的燃料在运行几年以后还可以重新再装备一座新的反应堆，显示出极高的经济性。

然而，这种反应堆的燃料回路放射性很强，结构材料腐蚀严重，且燃料后处理技术复杂，因此在工程上实现起来较为困难。熔盐堆的基本原理是使用Li、Be、Na、Zr等的氟化盐以及溶解的U、Pu、Th的氟化物熔融混合作为燃料，在600~700℃和低压条件下形成熔盐流，然后直接进入热交换器进行热量交换。

Molten salt reactor is a type of reactor that uses molten salt, which is soluble in fissionable materials and in a molten state, as nuclear fuel. Its core structure is simple, and it can continuously add fuel and remove fission products during operation, thereby reducing the number of reactor shutdowns and effectively utilizing neutrons. The fuel burnup is not limited by radiation damage, allowing the fuel produced by a molten salt reactor to be equipped with a new reactor after several years of operation, demonstrating extremely high economic efficiency.

However, the fuel circuit of this type of reactor has strong radioactivity, severe corrosion of structural materials, and complex fuel post-treatment technology, making it difficult to implement in engineering. The basic principle of a molten salt reactor is to use fluorides such as Li, Be, Na, Zr, as well as dissolved fluorides of U, Pu, Th, etc. to melt and mix as fuel, forming a molten salt flow at 600-700 ℃ and low pressure conditions, and then directly entering the heat exchanger for heat exchange.

图6为印刷电路板式换热器的横截面，燃料盐和钠冷却剂通道交替设置。印刷电路板式换热器(PCHE)能够在紧凑的空间内大幅度增加换热的接触面积。

Figure 6 shows the cross section of a printed circuit heat exchanger. The fuel salt and sodium coolant channels are arranged alternately. Printed circuit heat exchangers (PCHE) provide a large heat exchange contact area in a compact space.

图6 印刷电路热交换器横截面，燃料盐和钠冷却剂通道交替设置

(未显示燃料盐和钠板之间的多孔板)

Fig.6 Cross section of the printed circuit heat exchanger with alternating fuel salt and sodium coolant channels

(Porous plate between fuel salt and sodium plate not shown)

本公司生产的印刷电路板式换热器，采用扩散焊等技术，实现高效热能交换。其结构紧凑、传热效果好，广泛应用于制冷、空调等领域。该换热器性能稳定、维护简便，为客户节能降耗，提升运行效率。选择我们，让热能传递更高效！

The printed circuit board heat exchangers produced by our company use diffusion welding technology to achieve efficient heat exchange. Its compact structure and good heat transfer effect are widely used in fields such as refrigeration and air conditioning. This heat exchanger has stable performance and easy maintenance, which saves energy and reduces consumption for customers and improves operational efficiency. Choose us to make heat transfer more efficient!