CN117588973A - Plate heat exchanger and use method thereof - Google Patents

Abstract

The invention relates to the technical field of heat exchangers, and specifically relates to a plate heat exchanger and a method of using the same. It includes an existing plate heat exchanger, a heat medium inlet, a cold medium outlet, and a heat medium Short pipes are installed at the outlet and the cold medium inlet, and connected descaling valves are installed on the short pipes. A first flushing pipe and a second flushing pipe are provided on one side of the plate heat exchanger. The first flushing pipe It is connected with the ends of the two descaling valves, and the second flushing pipe is connected with the ends of the other two descaling valves. A water pump is installed in communication between the first flushing pipe and the second flushing pipe. The first flushing pipe and the second flushing pipe Together with the valve, a flushing pipe is formed. A dosing pipe is installed on the first flushing pipe or the second flushing pipe. A dosing valve is installed on the dosing pipe. The bottom of one side of the plate heat exchanger is provided with a third pipe fixedly connected to the flushing pipe. A sewage pipe, with a first sewage valve fixedly installed on the first sewage pipe.

Description

A plate heat exchanger and its use method

Technical field

The present invention relates to the technical field of heat exchangers, and in particular to a plate heat exchanger and a method of using it.

Background technique

Plate heat exchanger technology has developed very maturely and has been widely used in all walks of life. It is the preferred heat exchange equipment in the central heating heat exchange industry. Due to the wide range of domestic water heat exchange and long pipelines, granular impurities such as sediment and iron filings often block the heat exchanger. In addition, the hardness of the water quality is not well controlled, which can easily cause scaling on the surface of the heat exchanger plates. This will lead to an increase in the pressure drop of plate heat exchangers, an increase in power consumption, and a decrease in heat exchange efficiency, which will affect the normal use of users, and the performance of the heat exchanger will be weakened. At the same time, it will also increase energy consumption and cause problems for users. Increase in costs.

In order to solve the problem of blockage and scaling of the heat exchanger, it is necessary to remove the impurities entering the heat exchanger and understand whether the heat exchanger plate group is scaled. In the existing technology, holes are usually made in the movable plate of the plate heat exchanger, and the opened holes are blocked with blind plates. When the sewage is discharged and the scaling in the plate group is inspected, the blind plates are removed for cleaning and inspection. . Using the blind plate sealing method, it is difficult to grasp the timing of opening the blind plate to drain the waste, because the scaling and fouling of the plate group inside the heat exchanger cannot be seen. When the blind plate is often disassembled, it is found that there are few impurities or no scaling. , which is time-consuming and laborious. Frequent disassembly and assembly of blind plates can easily lead to damage to the sealing structure and water leakage, shortening the service life of the heat exchanger.

At the same time, when the heat exchanger fails, it is necessary to determine whether internal leakage occurs in the plate heat exchanger and where the internal leakage occurs. Since there is no direct observation point for the plate heat exchanger blocked by the blind plate, it is impossible to observe online where there is internal leakage inside the plate heat exchanger. The running heat exchanger system can only be shut down and dismantled gradually. Troubleshoot or remove sewage and descale.

The most important thing is that in extremely cold weather, that is, the peak period of heating, if the heat exchanger is blocked and scaled, the efficiency of the heat exchanger will decrease and the resistance of the unit system will increase. In such cases, the frequency of the circulating water pump motor will be increased to increase When the flow rate cannot meet the required heating demand, the heat exchanger plate group can only be shut down for a long time and manually dismantled, and each plate should be soaked, rinsed, descaled and drained with potion. If the processing time is long, it will cause the heating problem. The regional cold pipe network freezes and cracks, causing immeasurable losses and serious consequences to users.

To sum up, in the existing technology, plate heat exchangers on the market mainly have the problem that it is difficult to clean when there is scale between the plates. Each plate needs to be disassembled and soaked and rinsed with medicinal water, which takes a long time to process.

The above information disclosed in the Background section is only for enhancement of understanding of the context of the disclosure and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.

Contents of the invention

The purpose of the present invention is to design a plate heat exchanger that can quickly clean the clogging dirt between the plates without disassembling the plates of the heat exchanger according to the scaling conditions inside the heat exchanger. and methods of using them to address the above deficiencies in the technology.

In order to achieve the above object, the present invention provides the following technical solution: a plate heat exchanger and its use method, including an existing plate heat exchanger, a heat medium inlet, a cold medium outlet, a heat medium outlet and a heat medium outlet on the front end plate of the plate heat exchanger. The medium outlet and the cold medium inlet are equipped with short pipes, and connected descaling valves are installed on the short pipes. A first flushing pipe and a second flushing pipe are provided on one side of the plate heat exchanger. The first flushing pipe The pipe is connected with the ends of the two descaling valves, and the second flushing pipe is connected with the ends of the other two descaling valves. A water pump is installed in communication between the first flushing pipe and the second flushing pipe. The first flushing pipe and the second flushing pipe are connected with each other. The pipe and the valve together form a flushing pipe. A dosing pipe is installed on the first flushing pipe or the second flushing pipe. A dosing valve is installed on the dosing pipe. The bottom of one side of the plate heat exchanger is provided with a fixed connection with the flushing pipe. The first sewage pipe has a first sewage valve fixedly installed on the first sewage pipe.

Preferably, two chemical sight glasses are detachably connected to the top of the rear end plate of the plate heat exchanger, and the central axes of the two chemical sight glasses coincide with the central axes of the corner holes on the plates of the plate heat exchanger respectively;

Use the chemical sight glass with the central axis coincident to observe the scaling inside the plate heat exchanger through the corner holes of the plate.

Preferably, a detachable lighting lamp is rotatably connected to the surface of the chemical sight glass;

Use lighting to assist staff in observing conditions inside the plate heat exchanger in areas with poor lighting.

Preferably, two blind plates are detachably connected to the bottom of the rear end plate of the plate heat exchanger, and the central axes of the two blind plates coincide with the central axes of the corner holes on the plates of the plate heat exchanger respectively;

The detachable blind plate is used to facilitate the user to remove the larger dirt blockage in the plate heat exchanger.

Preferably, a second drain pipe is provided on one side of the rear end plate of the plate heat exchanger. The second drain pipes are fixedly connected and communicated with the two blind plates respectively. The second drain pipes are also fixedly installed with respectively controlled The second drain valve determines whether the two blind plates are connected or not;

By opening the second drain pipe, the liquid in the plate heat exchanger, mixed with small dirt plugs, can pass through the blind plate and enter the second drain pipe, and then be discharged.

Preferably, the ends of the short pipes at the hot medium inlet, cold medium outlet, hot medium outlet, and cold medium inlet are all fixedly installed with main valves connected to external pipes;

The main valve is used to control whether the liquid in the external pipe can enter the plate heat exchanger through the hot medium inlet, cold medium outlet, hot medium outlet or cold medium inlet through the short pipe.

In a second aspect, the present invention also proposes a method of using a plate heat exchanger for the above-mentioned plate heat exchanger. The method of use includes the steps:

S1. Observe the inside of the plate heat exchanger through the chemical sight glass on the rear end plate of the plate heat exchanger. Define the channel connecting the hot medium inlet and the hot medium outlet as the hot liquid channel, and define the channel connecting the cold medium inlet and the cold medium outlet. The channel is defined as the cold liquid channel, and the scaling conditions in the cold liquid channel and hot liquid channel are observed;

S2. When it is observed that the scaling phenomenon in the hot liquid channel/cold liquid channel of the plate heat exchanger reaches the level that needs to be cleaned, close the two main valves controlling the hot liquid channel/cold liquid channel, and open the dosing valve to use external The dosing pump that is detachable from the dosing tube pumps the medicinal solution into the dosing tube until it enters the flushing pipe and then closes the dosing valve;

S3. Open the two descaling valves that connect the hot liquid channel/cold liquid channel, connect the hot liquid channel/cold liquid channel, the short pipe, the first flushing pipe and the second flushing pipe to form a descaling channel, and start the water pump to drive The chemical liquid is circulated and flushed in the descaling channel for a predetermined period of time, and then the water pump is turned off and left to stand until the scale is observed to dissolve into powder through the chemical sight glass;

S4. After restarting the water pump for a predetermined period of time, open the first drain valve. The liquid medicine mixed with powdery scale in the descaling channel will be discharged through the first drain pipe. After the liquid in the descaling channel is drained, close the first drain valve;

S5. Open the dosing valve and pump external clean water into the descaling channel through the dosing pipe until it is full. Then close the dosing valve and start the water pump for the predetermined cleaning time. After the water pump works for the cleaning time, close and open the first drain valve to discharge. Clean water after cleaning, and repeat S5 for a predetermined number of times;

S6. Close the descaling valve, dosing valve, and first drain valve, and open the closed main valve to complete the internal scale treatment process of the plate heat exchanger.

Preferably, in step S2, when it is observed that a blockage occurs in the hot liquid channel/cold liquid channel, the second drain valve corresponding to the hot liquid channel/cold liquid channel is opened, and the liquid in the hot liquid channel/cold liquid channel will flush out the blockage. The waste is discharged along the blind plate and the second sewage pipe.

Preferably, in step S2, when it is observed that the larger dirt blockage in the plate heat exchanger cannot be discharged by opening the second drain valve, the two main valves corresponding to the hot liquid channel/cold liquid channel are closed, and the corresponding hot liquid channel/cold liquid channel is opened. For the blind plate of the cold liquid channel, remove the large dirt blockage and reset the blind plate and main valve.

Preferably, in step S4, the second drain valve is opened simultaneously when the first drain valve is opened. The chemical liquid mixed with powdery scale in the descaling channel will be discharged through the blind plate and the second drain pipe, and will be closed when the first drain valve is closed. When the second drain valve is closed simultaneously.

In the above technical solutions, the technical effects and advantages provided by the present invention are:

This product is assembled by adding parts to the front end plate of the plate heat exchanger, and can clean the hot liquid channel/cold liquid channel online directly on the plate heat exchanger without stopping the machine. scale, which solves the problem in the existing technology that each plate needs to be disassembled and soaked and rinsed with medicinal water, which takes a long time to process;

This product adds a small number of parts and makes little changes to the heat exchanger itself. It can be directly upgraded on the existing plate heat exchanger, which not only reduces the production cost, but also reduces the cost of upgrading;

When this product is used to deal with small fouling or scale in the plate heat exchanger, there is no need to disassemble the plates for treatment like in the prior art, which reduces the problem of reduced sealing caused by frequent disassembly;

This product can observe the fouling or scaling inside the plate heat exchanger through a chemical sight glass, and actively clean it when necessary. Unlike the blind plate method in the existing technology, it is difficult to observe the inside of the plate heat exchanger. situation to further avoid the problem of reduced performance of the sealing structure caused by frequent disassembly and assembly;

This product can use the chemical sight glass in conjunction with the scale removal steps to observe where side leakage occurs in the plate removal group. The side leakage location can be quickly determined for troubleshooting and maintenance. There is no need to disassemble all the plates for inspection like the existing technology. .

Description of drawings

In order to more clearly explain the embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description only describe the present invention. For some embodiments, those of ordinary skill in the art can also obtain other drawings based on these drawings.

Figure 1 is a schematic diagram of the overall structure of the present invention;

Figure 2 is a perspective view of the present invention;

Figure 3 is a disassembled schematic diagram of the present invention;

Figure 4 is a first view of the working state of the prior art of the present invention;

Figure 5 is a second view of the prior art working state of the present invention.

Explanation of reference symbols:

1. Plate heat exchanger; 101. Front end plate; 102. Hot medium inlet; 103. Cold medium outlet; 104. Hot medium outlet; 105. Cold medium inlet; 106. Back end plate; 107. Plate; 2. Short Section pipe; 3. Descaling valve; 4. Flushing pipe; 401. First flushing pipe; 402. Second flushing pipe; 5. Water pump; 6. Dosing pipe; 7. Dosing valve; 8. First sewage pipe ; 9. First drain valve; 10. Chemical sight glass; 11. Lighting lamp; 12. Blind plate; 13. Second drain pipe; 14. Second drain valve; 15. Main valve.

Implementation

In order to enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of this application. , not all examples. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of this application.

It should be noted that the structures, proportions, sizes, etc. shown in the drawings of this specification are only used to coordinate with the content disclosed in the specification for the understanding and reading of people familiar with this technology, and are not used to limit the conditions for the implementation of this application. , so it has no technical substantive significance. Any structural modifications, changes in proportions, or adjustments in size, without affecting the effectiveness and purpose of this application, should still fall within the scope of what is disclosed in this application. The technical content must be within the scope of coverage.

Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more example embodiments. In the following description, numerous specific details are provided to provide a thorough understanding of example embodiments of the present disclosure. However, those skilled in the art will appreciate that the technical solutions of the present disclosure may be practiced without one or more of the specific details being omitted, or other methods, components, steps, etc. may be adopted. In other instances, well-known structures, methods, implementations, or operations have not been shown or described in detail to avoid obscuring aspects of the disclosure.

In order to better understand the above technical solution, the above technical solution will be described in detail below with reference to the accompanying drawings and specific implementation modes.

The present invention provides a plate heat exchanger and its use method as shown in Figures 1-5, including an existing plate heat exchanger 1. This heat exchanger should have the general structure of the existing plate heat exchanger 1. , such as the front end plate 101, the plate group 107, the rear end plate 106, the guide rod, etc., the front end plate 101 also has a hot medium inlet 102, a cold medium outlet 103, a hot medium outlet 104, a cold medium inlet 105, the municipal network The liquid enters from the heat medium inlet 102 and is discharged from the heat medium outlet 104 to form a hot liquid channel. The liquid in the residential network enters from the cold medium inlet 105 and is discharged from the cold medium outlet 103 to form a cold liquid channel;

On the front end plate 101, a short pipe 2 is fixedly installed at the hot medium inlet 102, the cold medium outlet 103, the hot medium outlet 104, and the cold medium inlet 105. The end of the short pipe 2 is fixedly installed with a main pipe connected to the outside pipe. Valve 15, a descaling valve 3 is fixedly installed on the outer wall of each short pipe 2, and a flushing pipe 4 is provided on one side of the front end plate 101. The flushing pipe 4 is composed of a first flushing pipe 401 and a second flushing pipe 402. The flushing pipe 401 is fixedly connected and communicated with the ends of the two descaling valves 3, and the second flushing pipe 402 is fixedly connected and communicated with the ends of the other two descaling valves 3. Between the first flushing pipe 401 and the second flushing pipe 402 A water pump 5 is installed between them through quick-release screws, preferably a backwash circulating water pump 5. The input end and output end of the water pump 5 are detachably connected to the ends of the first flushing pipe 401 and the second flushing pipe 402 respectively. A dosing pipe 6 needs to be installed on the first flushing pipe 401 or the second flushing pipe 402. The dosing pipe 6 can be detachably connected to the existing external dosing pump. A dosing valve 7 needs to be installed on the dosing pipe 6 to control the dosing pipe. 6 is connected or not, finally a first sewage pipe 8 needs to be installed below the flushing pipe 4, and a first sewage valve 9 is fixedly installed on the sewage pipe;

Above the rear end plate 106, two chemical sight glasses 10 need to be removably installed at positions corresponding to the corner holes of the plate group 107. The structure and installation method of this chemical sight glass 10 can be referred to the application number applied by our company: 202420079151. Below the rear end plate 106, refer to the utility model patent applied by our company with the application number: 2023233264429. Under the rear end plate 106, two blind plates 12 can be detachably installed at the positions corresponding to the corner holes of the plate 107 group, and two blind plates 12 are removable. A second drain pipe 13 is installed on each blind plate 12, and a second drain valve 14 for controlling the communication or closing of the blind plate 12 is installed on the second drain pipe 13.

When a dirt blockage occurs inside the heat exchanger, the user can open the second drain valve 14 corresponding to the hot liquid channel/cold liquid channel, so that the liquid in the hot liquid channel/cold liquid channel, mixed with the dirt blockage, passes through the blind plate 12 flows into the second drain pipe 13, and finally discharges from the plate heat exchanger 1, and then closes the second drain valve 14;

If the dirt blockage in the heat exchanger is too large and cannot be discharged through the second drain pipe 13, close the two main valves 15 corresponding to the inlet and outlet of the hot liquid channel/cold liquid channel, and then remove the blind plate 12, which will make it difficult to Remove the discharged dirt and blockage, then install the blind plate 12 and open and close the two main valves 15;

When scaling occurs in the heat exchanger and reaches a state that requires cleaning, the user needs to first close the two main valves 15 corresponding to the inlet and outlet of the hot liquid channel/cold liquid channel, and the other cold liquid channel/heat The liquid channel works normally, and then the output end of the dosing pump in the prior art is installed at the end of the dosing pipe 6, and the dosing valve 7 is opened, so that the dosing pump injects the scale-dissolving liquid into the flushing pipe 4, and then closes it. Dosing valve 7, and open the descaling valve 3 installed on the short pipe 2 corresponding to the hot liquid channel/cold liquid channel that needs to be cleaned. At this time, the hot liquid channel/cold liquid channel, flushing pipe 4, and short pipe 2 Form a descaling channel;

Start the water pump 5. The water pump 5 drives the solution to dissolve in the descaling channel and circulates for flushing. After flushing for about 10 minutes, turn off the water pump 5. Let it stand and observe whether the scale is dissolved into powder. If it is powdery, start the water pump 5 again and run for 20 minutes before stopping. , and then open the drain valve on the first drain pipe 8 to allow the liquid in the descaling channel mixed with scale powder to be discharged from the descaling channel. At this time, the second drain valve 14 can also be opened simultaneously to allow the liquid to flow from the second drain pipe 8. They are discharged together in tube 13 to accelerate the discharge speed;

After the liquid is drained, close the first drain valve 9 and the second drain valve 14, open the dosing valve 7, pump external clean water into the descaling channel through the dosing pipe 6, close the dosing valve 7 again and start the water pump 5. , let the clean water flush in the descaling channel, then close the water pump 5, open the first drain valve 9 and the second drain valve 14 to discharge the clean water, perform this clean water cleaning step multiple times according to the actual working conditions, until there is no water in the descaling channel. residual potion;

Finally, close the already opened descaling valve 3, the first drain valve 9, the second drain valve 14, and the dosing valve 7, and open the closed main valve 15 to complete the scale treatment steps in the plate heat exchanger 1. ;

If the group of plates 107 is damaged, but it is not known which piece is damaged, the existing technology will need to disassemble all the plates 107 to observe one by one. This product only needs to close the two corresponding hot liquid channels/cold liquid channels. a main valve 15, then open the second drain valve 14 to drain the liquid in the hot liquid channel/cold liquid channel, then close the second drain valve 14, and the staff observes the plate 107 that has been emptied of liquid through the chemical sight glass 10 When the lighting is not good, you can turn on the lighting 11 to observe which area the liquid gradually enters, that is, liquid penetrates into the cold liquid channel/hot liquid channel that has not been closed, especially in the damaged part of the gap, that is, Quickly find out which side plate 107 is damaged. There is no need to disassemble all the plates 107 to determine the location of the internal leakage like in the prior art. The fault can be quickly eliminated and repaired, eliminating the need for long downtime to disassemble the heat exchanger inspection plate. The problem of leakage within the group.

It is important to note that the construction and arrangements of the present application shown in various exemplary embodiments are illustrative only. Although only a few embodiments are described in detail in this disclosure, those reviewing this disclosure will readily appreciate that many modifications are possible without materially departing from the novel teachings and advantages of the subject matter described in this application. is possible (e.g. changes in size, scale, structure, shape and proportion of various elements, as well as parameter values (e.g. temperature, pressure, etc.), mounting arrangements, use of materials, colors, orientations, etc.). For example, an element shown as integrally formed may be constructed from multiple parts or elements, the position of elements may be inverted or otherwise altered, and the nature or number or position of discrete elements may be altered or varied. Accordingly, all such modifications are intended to be included within the scope of this invention. The order or sequence of any process or method steps may be changed or reordered according to alternative embodiments. In the claims, any "means-plus-function" clause is intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Other substitutions, modifications, changes and omissions may be made in the design, operation and arrangement of the exemplary embodiments without departing from the scope of the invention. Therefore, the invention is not limited to particular embodiments, but extends to various modifications which still fall within the scope of the appended claims.

Furthermore, in order to provide a concise description of the exemplary embodiments, not all features of an actual implementation may be described (i.e., those features that are not relevant to the best mode presently contemplated for carrying out the invention, or that are not relevant to carrying out the invention) feature).

It is understood that numerous implementation-specific decisions may be made during the development of any actual implementation, as in any engineering or design project. Such a development effort might be complex and time consuming, but would be a routine undertaking of design, manufacture and production without undue experimentation to those of ordinary skill having the benefit of this disclosure .

It should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solution of the present invention can be carried out. Modifications or equivalent substitutions without departing from the spirit and scope of the technical solution of the present invention shall be included in the scope of the claims of the present invention.

Claims (10)

1. The utility model provides a plate heat exchanger and application method thereof, includes current plate heat exchanger (1), and heat medium entry (102), cold medium export (103), heat medium export (104), cold medium entry (105) department on front end plate (101) of plate heat exchanger (1) all install short-tube (2), its characterized in that: the utility model discloses a heat exchanger, including nipple joint pipe (2), first flushing pipe (401) and second flushing pipe (402) are provided with on one side of plate heat exchanger (1), first flushing pipe (401) and two scale removal valve (3) tip intercommunication, second flushing pipe (402) and two other scale removal valve (3) tip intercommunication, water pump (5) are installed in the intercommunication between first flushing pipe (401) and second flushing pipe (402), first flushing pipe (401), second flushing pipe (402) and valve form flushing pipe (4) jointly, install on first flushing pipe (401) or second flushing pipe (402) and add pencil (6), install on adding pencil (6) and add pencil (7), the bottom of plate heat exchanger (1) one side is provided with first blow off pipe (8) with flushing pipe (4) fixed connection, first blow off valve (9) are installed on first blow off pipe (8).

2. A plate heat exchanger and method of use according to claim 1, wherein: two chemical industry sight glass (10) are detachably connected to rear end plate (106) top of plate heat exchanger (1), and the axis of two chemical industry sight glass (10) is coincident with the angular aperture axis on slab (107) of plate heat exchanger (1) respectively.

3. A plate heat exchanger and method of use according to claim 2, wherein: the surface of the chemical industry sight glass (10) is rotationally connected with a detachable illuminating lamp (11).

4. A plate heat exchanger and method of use according to claim 2, wherein: the bottom of the rear end plate (106) is detachably connected with two blind plates (12), and the central axes of the two blind plates (12) are respectively overlapped with the central axes of the corner holes on the plate (107) of the plate heat exchanger (1).

5. A plate heat exchanger and method of use according to claim 2, wherein: a second blow-down pipe (13) is arranged on one side of the rear end plate (106), the second blow-down pipe (13) is fixedly connected and communicated with the two blind plates (12) respectively, and a second blow-down valve (14) for controlling the communication of the two blind plates (12) respectively is fixedly arranged on the second blow-down pipe (13).

6. A plate heat exchanger and method of use according to claim 1, wherein: the main valves (15) communicated with the external pipelines are fixedly arranged at the ends of the short joint pipes (2) at the hot medium inlet (102), the cold medium outlet (103), the hot medium outlet (104) and the cold medium inlet (105).

7. A method of using a plate heat exchanger (1) for a plate heat exchanger (1) according to any one of claims 1-6, the method of using a plate heat exchanger (1) comprising the steps of:

s1, observing the inside of a plate heat exchanger (1) through a chemical view mirror (10) on a rear end plate (106), defining a channel which is communicated with a heat medium inlet (102) and a heat medium outlet (104) as a hot liquid channel, defining a channel which is communicated with a cold medium inlet (105) and a cold medium outlet (103) as a cold liquid channel, and observing scaling conditions in the cold liquid channel and the hot liquid channel;

s2, when the scaling phenomenon in a hot liquid channel/a cold liquid channel of the plate heat exchanger (1) is observed to reach the degree of cleaning, closing two main valves (15) for controlling the hot liquid channel/the cold liquid channel, opening a dosing valve (7), pumping the drug into the dosing pipe (6) by using a dosing pump which is detachable from the external and the dosing pipe (6), and closing the dosing valve (7) after entering a flushing pipeline (4);

s3, opening two descaling valves (3) corresponding to the hot liquid channel/cold liquid channel, enabling the hot liquid channel/cold liquid channel, the short pipe (2), the first flushing pipe (401) and the second flushing pipe (402) to be communicated to form a descaling channel, starting a water pump (5) to drive liquid medicine to circularly flush in the descaling channel for a preset time period, and then closing the water pump (5) to stand until scale is observed to be dissolved into powder through a chemical sight glass (10);

s4, after the water pump (5) is started again to work for a preset time, the first drain valve (9) is opened, mixed powder scale of the liquid medicine in the descaling channel is discharged through the first drain pipe (8), and after the liquid in the descaling channel is discharged, the first drain valve (9) is closed;

s5, opening a dosing valve (7), pumping external clear water into a descaling channel through a dosing pipe (6) until the descaling channel is filled, then closing the dosing valve (7) and starting a water pump (5) to work for a preset cleaning time, closing and opening a first blow-off valve (9) to discharge cleaned clear water after the water pump (5) works for the cleaning time, and repeating the step S5 for a preset number of times;

s6, closing the descaling valve (3), the dosing valve (7) and the first blow-down valve (9), and opening the closed main valve (15) to finish the process flow of reaching the scale inside the plate heat exchanger (1).

8. Use of a plate heat exchanger (1) according to claim 7, characterized in that: s2, when the occurrence of dirt blocking in the hot liquid channel/cold liquid channel is observed, a second blow-off valve (14) corresponding to the hot liquid channel/cold liquid channel is opened, and the liquid in the hot liquid channel/cold liquid channel is used for flushing dirt blocking objects and is discharged along the blind plate (12) and the second blow-off pipe (13).

9. Use of a plate heat exchanger (1) according to claim 8, characterized in that: s2, when the fact that larger dirt and blockage in the plate heat exchanger (1) cannot be discharged through opening of the second blow-down valve (14) is observed, two main valves (15) corresponding to the inlet and the outlet of the hot liquid channel/the cold liquid channel are closed, the blind plate (12) corresponding to the hot liquid channel/the cold liquid channel is detached, and after the larger dirt and blockage is drawn out, the blind plate (12) and the main valves (15) are reset.

10. Method of use X of a plate heat exchanger (1) according to claim 7, characterized in that: in the step S4, the second blow-down valve (14) is synchronously opened when the first blow-down valve (9) is opened, the liquid medicine mixed powder scale in the descaling channel can be discharged through the blind plate (12) and the second blow-down pipe (13), and the second blow-down valve (14) is synchronously closed when the first blow-down valve (9) is closed.