Anti-freezing heat exchange device

Abstract

An anti-freezing heat exchange device, comprising: a cold-side plate (1) provided with a first channel through which a first medium flows, wherein during the process of flowing from an input end to an output end, the first medium is changed from a liquid state to a gaseous state; intermediate plates (2), one side of each of which is attached to one side of the cold-side plate (1), wherein the intermediate plates (2) are provided with second channels, which are in communication with the output end of the first channel via communication holes to fill all or part of the gaseous first medium from the first channel into the second channels; and hot-side plates (3), which are attached to the other sides of the intermediate plates (2) and are provided with third channels through which a second medium flows. The intermediate plates (2) form buffer layers to protect the hot-side plates (3), thereby preventing direct heat transfer between hot and cold sides, and preventing the second medium inside the hot-side plates (3) from being frozen; moreover, the second channels do not rely on an additional medium, thereby eliminating the problem of contamination caused by leakage and cross-cavity mixing, and reducing costs.

Description

A freeze-proof heat exchange device

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 202411027911.3, filed on July 30, 2024, entitled "An Antifreeze Heat Exchange Device", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of heat exchange technology, specifically to an antifreeze heat exchange device. Background Technology

[0004] In the LNG (liquefied natural gas) industry chain, gasification is a crucial step in the gathering and transportation process. LNG absorbs heat in the vaporizer, transforming from a cryogenic fluid under supercritical pressure into a supercritical fluid at room temperature. Traditional LNG cryogenic heat exchangers suffer from problems such as large footprint, low heat exchange efficiency, wall frost formation, and internal freezing. Printed circuit board heat exchangers (PCHEs) are favored due to their high heat exchange efficiency and compact space utilization. While PCHEs offer advantages such as space saving and improved heat exchange efficiency, the persistent problems of wall frost formation and hot-side freezing severely restrict their efficient and continuous operation. Summary of the Invention

[0005] The technical problem to be solved by this application is to overcome the defects of wall frost and hot-side freezing in the process of using printed circuit board heat exchangers to exchange heat with liquefied natural gas, which seriously restrict the efficient and continuous operation of printed circuit board heat exchangers.

[0006] To overcome the above-mentioned defects, this application provides an antifreeze heat exchange device, comprising:

[0007] The cold side plate has a first channel in which a first medium flows; during the process of the first medium flowing from the input end to the output end of the first channel, the first medium changes from a liquid state to a gaseous state.

[0008] An intermediate plate is attached to one side of the cold side plate. The intermediate plate has a second channel, which is connected to the output end of the first channel through a connecting hole, so as to fill all or part of the gaseous first medium in the first channel into the second channel.

[0009] A hot side plate is attached to the other side of the middle plate. A third channel is provided on the hot side plate, and a second medium flows in the third channel. The temperature of the liquid first medium is lower than the freezing point of the second medium. The temperature of the first medium that has absorbed heat and vaporized is higher than the freezing point of the second medium.

[0010] Optionally, another intermediate plate through which a gaseous first medium flows is symmetrically attached to the other side of the cold side plate; and a hot side plate through which a second medium flows is symmetrically attached to the outside of the other intermediate plate.

[0011] Optionally, the input end of the second channel is connected to the output end of the first channel, and the output end of the second channel is adapted to output the first medium in its entirety in gaseous state.

[0012] Optionally, a portion of the gaseous first medium in the first channel is filled into the second channel, and the remaining gaseous first medium in the first channel is output from the output end of the first channel.

[0013] Optionally, the first medium is natural gas.

[0014] Optionally, the second medium is an aqueous solution of ethylene glycol.

[0015] Optionally, the first channel, the second channel, and the third channel are all microchannels.

[0016] Optionally, the antifreeze heat exchange device is a printed circuit board type heat exchanger.

[0017] Optionally, the microchannels are fabricated by brazing or diffusion welding.

[0018] Optionally, the microchannels of the first channel, the second channel, and the third channel are multiple parallel microchannels.

[0019] The technical solution described in this application has the following advantages over the prior art:

[0020] 1. The antifreeze heat exchange device provided in this application includes: a cold side plate with a first channel in which a first medium flows; during the process of the first medium flowing from the input end to the output end of the first channel, the first medium changes from a liquid state to a gaseous state; an intermediate plate attached to one side of the cold side plate, with a second channel in the intermediate plate, the second channel being connected to the output end of the first channel through a connecting hole to fill all or part of the gaseous first medium in the first channel into the second channel; and a hot side plate attached to the other side of the intermediate plate, with a third channel in the hot side plate in which a second medium flows; the temperature of the liquid first medium is lower than the freezing point of the second medium; the temperature of the first medium that has absorbed heat and vaporized is higher than the freezing point of the second medium; the present application adopts the above technical solution, forming a buffer layer through the intermediate plate to protect the hot side plate, preventing direct heat transfer between the cold and hot sides, preventing the second medium in the hot side plate from freezing, thereby avoiding the problem of the second medium freezing due to long-term ultra-low temperature operation of the hot side plate, and making the heat exchange process more reliable. Furthermore, the use of a stacked finned design increases fluidity, improves heat exchange efficiency, and results in more uniform flow and temperature distribution. Simultaneously, the second channel in this application does not rely on an additional medium, eliminating contamination issues caused by leakage and cross-contamination, while also reducing costs. When this technical solution is applied to printed circuit board (PCB) heat exchangers, it prevents wall frost formation and hot-side freezing, ensuring efficient and continuous operation of the PCB heat exchanger.

[0021] 2. In this application, another intermediate plate through which a gaseous first medium flows is symmetrically attached to the other side of the cold side plate; and a hot side plate through which a second medium flows is symmetrically attached to the outside of the other intermediate plate. In this application, the intermediate plate and the hot side plate form a longitudinal wrapping structure, which can make the flow rate and temperature distribution more uniform and achieve the purpose of antifreeze; it has a better internal heat exchange effect, avoids freezing caused by uneven local temperature, and improves heat exchange efficiency.

[0022] 3. The second medium in this application is an aqueous solution of ethylene glycol; this application adopts the above technical solution to prevent the aqueous solution of ethylene glycol in the hot side plate from freezing, and further prevents the aqueous solution of ethylene glycol in the LNG heat exchanger in the prior art from freezing, which would lead to the failure of the heat exchanger.

[0023] 4. The microchannels of the first, second, and third channels in this application are multiple parallel microchannels; this application adopts the above technical solution to further improve heat exchange efficiency. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 is a schematic diagram of the antifreeze heat exchange device provided in the embodiment of this application;

[0026] Figure 2 is a schematic diagram of the antifreeze heat exchange device provided in the embodiment of this application.

[0027] Figure 3 is a schematic diagram of the antifreeze heat exchange device provided in the embodiments of this application.

[0028] Explanation of reference numerals in the attached drawings: 1. Cold side plate; 2. Middle plate; 3. Hot side plate. Detailed Implementation

[0029] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0030] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0031] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0032] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0033] One specific embodiment of the antifreeze heat exchange device shown in Figures 1 to 3 includes: a cold side plate 1, an intermediate plate 2, and a hot side plate 3. The antifreeze heat exchange device described in this application is widely used in low-temperature heat exchange applications such as petrochemicals and shipbuilding.

[0034] As shown in Figures 1 and 3, the cold-side plate 1 has a first channel through which a first medium flows. During the flow of the first medium from the input end to the output end of the first channel, the first medium changes from a liquid state to a gaseous state. One side of the intermediate plate 2 is attached to one side of the cold-side plate 1. The intermediate plate 2 has a second channel, which is connected to the output end of the first channel through a connecting hole, allowing all or part of the gaseous first medium in the first channel to be filled into the second channel. The arrows in Figures 1 and 3 indicate the flow direction of the first or second medium. Specifically, the first medium is natural gas; the second medium is an aqueous solution of ethylene glycol. The antifreeze heat exchange device is a printed circuit board heat exchanger.

[0035] The hot side plate 3 is attached to the other side of the middle plate 2. The hot side plate 3 is provided with a third channel, in which a second medium flows. The temperature of the liquid first medium is lower than the freezing point of the second medium. The temperature of the first medium that has absorbed heat and vaporized is higher than the freezing point of the second medium.

[0036] Optionally, another intermediate plate 2, through which a gaseous first medium flows, is symmetrically attached to the other side of the cold side plate 1; and a hot side plate 3, through which a second medium flows, is symmetrically attached to the outside of the other intermediate plate 2.

[0037] As shown in Figure 1, a portion of the gaseous first medium in the first channel is filled into the second channel, and the remaining gaseous first medium in the first channel is output from the output end of the first channel.

[0038] The overall flow heat exchange process of the first medium is briefly described as follows: Liquid cryogenic natural gas enters from the input end of the first channel of the cold side plate 1, continuously exchanging heat along the first channel to the connecting hole. A small portion of the medium-temperature natural gas formed after vaporization enters the intermediate plate 2 adjacent to both sides along the connecting hole, forming medium-temperature gaseous natural gas. This creates a temperature buffer layer between the high-temperature and low-temperature media, thereby reducing the temperature difference between the hot and cold sides and achieving an antifreeze effect. Furthermore, the hot side of this structure constantly exchanges heat with the medium-temperature gaseous natural gas, minimizing the impact on the structure's heat exchange efficiency. The remaining gaseous natural gas flows out of the first channel. Throughout the natural gas flow process, the intermediate plate 2 continuously exchanges heat with the hot side plate 3, and the cold side plate 1 continuously exchanges heat with the intermediate plate 2, ultimately completing the heat exchange. The antifreeze principle is briefly described as follows: When the ethylene glycol aqueous solution flows, heat is transferred to the medium-temperature gaseous natural gas. Simultaneously, the medium-temperature gaseous natural gas also constantly exchanges heat with the cryogenic liquid natural gas. At this time, the intermediate plate 2 acts as a temperature buffer layer, avoiding direct contact between the hot side and the cold side, thereby achieving antifreeze on the hot side through the intermediate plate 2.

[0039] As shown in Figure 3, the input end of the second channel is connected to the output end of the first channel, and the output end of the second channel is suitable for outputting all gaseous first medium. After being redistributed through the connecting hole, the gaseous natural gas enters the intermediate plates 2 on both sides. The intermediate plates 2 exchange heat with the hot side plate 3 and the cold side plate 1 simultaneously. When the ultra-low temperature liquefied natural gas flows through the cold side plate 1, it exchanges heat with the medium temperature gaseous natural gas flowing through the intermediate plate 2. Therefore, when all the low temperature natural gas enters the intermediate plate 2, it has already begun to heat up and vaporize. Thus, the temperature gradient when the high temperature ethylene glycol aqueous solution exchanges heat with the medium temperature gaseous natural gas in the intermediate plate 2 is small, thereby achieving the purpose of antifreeze. Since the heat of the hot side plate 3 is always exchanging heat with the gaseous natural gas, the heat exchange efficiency of this structure is minimally affected. Furthermore, after the low temperature liquefied natural gas flows through the connecting hole of the cold side plate 1, it flows into the intermediate plates 2 on both sides. At this time, the first medium undergoes mixing, collision, and redistribution at the connecting hole, making the flow rate and temperature distribution more uniform.

[0040] As shown in Figure 2, the first, second, and third channels are all microchannels; these microchannels are fabricated using brazing or diffusion welding; each of the first, second, and third channels consists of multiple parallel microchannels. Compared to traditional shell-and-tube structures, the technical solution of this application has a wider range of applications and a smaller volume. The microchannels described in this application can be formed in one step through diffusion welding or brazing using laminated plates. There are no internal welding points, so any leakage is readily apparent, preventing media cross-contamination caused by leakage from the intermediate plate 2.

[0041] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this application.

Claims

1. A freeze protection heat exchanger, comprising: The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device.

2. The freeze prevention heat exchanger of claim 1, wherein The application relates to an anti-freezing heat exchange device.

3. The freeze prevention heat exchanger of claim 1, wherein The application relates to an anti-freezing heat exchange device.

4. The freeze prevention heat exchanger of claim 1, wherein The application relates to an anti-freezing heat exchange device.

5. The freeze prevention heat exchanger of any one of claims 1-4, wherein, The application relates to an anti-freezing heat exchange device.

6. The freeze prevention heat exchanger of claim 5, wherein The application relates to an anti-freezing heat exchange device.

7. The freeze prevention heat exchanger of any one of claims 1-4, wherein, The application relates to an anti-freezing heat exchange device.

8. The freeze prevention heat exchanger of claim 7, wherein The application relates to an anti-freezing heat exchange device.

9. The freeze prevention heat exchanger of claim 7, wherein The application relates to an anti-freezing heat exchange device.

10. The freeze prevention heat exchanger of claim 7, wherein The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application relates to an anti-freezing heat exchange device. The application

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