CN111780592A

CN111780592A - Heat exchanger with four fluid pressure difference memory regulation

Info

Publication number: CN111780592A
Application number: CN202010708001.7A
Authority: CN
Inventors: 王逸隆; 侯钦鹏
Original assignee: Qingdao University of Science and Technology
Current assignee: Qingdao University of Science and Technology
Priority date: 2020-07-21
Filing date: 2020-07-21
Publication date: 2020-10-16

Abstract

The invention provides a heat exchanger with four fluid pressure difference memory regulation, wherein inlets of a first heat exchange tube, a second heat exchange tube and a third heat exchange tube are respectively provided with a first valve, a second valve and a third valve; the accumulated data of the pressure difference or the pressure difference change of the first pressure sensor, the second pressure sensor and the third pressure sensor are stored in a database in real time, and a one-dimensional deep convolution neural network is adopted to extract data characteristics and perform mode identification, so that the opening and closing of the first valve, the second valve and the third valve are controlled, and whether the first fluid, the third fluid and the second fluid exchange heat or not is controlled. The shell-and-tube heat exchanger can realize the periodic frequent vibration of the heat exchange tube, and improves the heating efficiency, thereby realizing good descaling and heating effects.

Description

Heat exchanger with four fluid pressure difference memory regulation

Technical Field

The invention relates to a shell-and-tube heat exchanger, in particular to a shell-and-tube heat exchanger for intermittent vibration descaling.

Background

The invention relates to heat exchanger descaling, which is a novel invention applied to a shell-and-tube heat exchanger on the basis of research and development of Qingdao science and technology university (application number 2019101874848).

The shell-and-tube heat exchanger is widely applied to industries such as chemical industry, petroleum industry, refrigeration industry, nuclear energy industry and power industry, and due to the worldwide energy crisis, the demand of the heat exchanger in industrial production is more and more, and the quality requirement of the heat exchanger is higher and more. In recent decades, although compact heat exchangers (plate type, plate fin type, pressure welded plate type, etc.), heat pipe type heat exchangers, direct contact type heat exchangers, etc. have been rapidly developed, because the shell and tube type heat exchangers have high reliability and wide adaptability, they still occupy the domination of yield and usage, and according to relevant statistics, the usage of the shell and tube type heat exchangers in the current industrial devices still accounts for about 70% of the usage of all heat exchangers.

After the shell-and-tube heat exchanger is scaled, the heat exchanger is cleaned by adopting conventional modes of steam cleaning, back flushing and the like, and the production practice proves that the effect is not good. The end socket of the heat exchanger can only be disassembled, and a physical cleaning mode is adopted, but the mode is adopted for cleaning, so that the operation is complex, the consumed time is long, the investment of manpower and material resources is large, and great difficulty is brought to continuous industrial production.

The mode of passively strengthening heat exchange is to strictly prevent the fluid vibration induction in the heat exchanger from being changed into effective utilization of vibration, so that the convective heat transfer coefficient of the transmission element at low flow speed is greatly improved, dirt on the surface of the heat transfer element is restrained by vibration, the thermal resistance of the dirt is reduced, and the composite strengthened heat transfer is realized.

In application, it is found that continuous heat exchange can cause the internal fluid to form stability, i.e. the fluid does not flow or has little fluidity, or the flow is stable, so that the vibration performance of the heat exchange tube is greatly weakened, and therefore, the descaling of the heat exchange tube and the heat exchange efficiency are influenced. There is therefore a need for improvements to the above-described heat exchangers.

The heat exchanger generally exchanges heat by two fluids, and the heat exchange of four fluids is rarely researched, the four-fluid heat exchange is researched, a novel induced vibration four-fluid shell-and-tube heat exchanger is developed,

current shell and tube heat exchangers include dual headers, one header evaporating and one header condensing, thereby forming a vibrating descaled heat pipe. Thereby improving the heat exchange efficiency of the heat pipe and reducing scaling. However, the heat pipe has insufficient uniformity of heat exchange, only one side is used for condensation, and the heat exchange amount is small, so that improvement is needed to develop a heat pipe system with a novel structure. There is therefore a need for improvements to the above-described heat exchangers.

In the prior application, a shell-and-tube heat exchanger for exchanging heat of four fluids has been developed, but the shell-and-tube heat exchanger is controlled according to the period, so that the vibration heat exchange effect is poor, and the intelligent degree is low. The present application therefore provides further improvements over the previous studies.

Disclosure of Invention

The invention provides a four-fluid shell-and-tube heat exchanger with a novel structure aiming at the defects of a shell-and-tube heat exchanger in the prior art. The shell-and-tube heat exchanger can realize heat exchange of four fluids, and the periodic frequent vibration of the heat exchange tubes improves the heat exchange efficiency, thereby realizing good descaling and heat exchange effects. The heat exchanger structure is particularly suitable for heat exchangers arranged in the horizontal direction.

In order to achieve the purpose, the invention adopts the following technical scheme:

a four-fluid pressure difference memory-regulated heat exchanger comprises a shell, a heat exchange part, a shell side inlet connecting pipe and a shell side outlet connecting pipe; the heat exchange component is arranged in the shell and fixedly connected to the front tube plate and the rear tube plate; the shell pass inlet connecting pipe and the shell pass outlet connecting pipe are both arranged on the shell; the shell pass fluid enters from a shell pass inlet connecting pipe, exchanges heat through the heat exchange part and exits from a shell pass outlet connecting pipe;

the heat exchange component comprises a central tube, a left tube, a right tube and tube groups, wherein the tube groups comprise a left tube group and a right tube group, the left tube group is communicated with the left tube and the central tube, the right tube group is communicated with the right tube and the central tube, so that the central tube, the left tube, the right tube and the tube groups form heat exchange fluid closed circulation, phase change fluid is filled in the left tube and/or the central tube and/or the right tube, each tube group comprises a plurality of circular arc-shaped annular tubes, the end parts of the adjacent annular tubes are communicated, the annular tubes form a serial structure, and the end parts of the annular tubes form free ends of the annular tubes; the central tube comprises a first tube orifice and a second tube orifice, the first tube orifice is connected with the inlet of the left tube group, the second tube orifice is connected with the inlet of the right tube group, the outlet of the left tube group is connected with the left tube, and the outlet of the right tube group is connected with the right tube; the first pipe orifice and the second pipe orifice are arranged on the same side of the central pipe; the left tube group and the right tube group are in mirror symmetry along the plane where the axis of the central tube is located;

a left return pipe is arranged between the left side pipe and the central pipe, and a right return pipe is arranged between the right side pipe and the central pipe;

the heat exchanger also comprises a first heat exchange tube, a second heat exchange tube and a third heat exchange tube, wherein the first heat exchange tube penetrates through the left side tube, the second heat exchange tube penetrates through the central tube, and the third heat exchange tube penetrates through the right side tube; the first heat exchange tube, the second heat exchange tube and the third heat exchange tube respectively flow through a first fluid, a second fluid and a third fluid;

the method is characterized in that the shell side fluid is a cold source, and the first fluid, the second fluid and the third fluid are heat sources; the inlets of the first heat exchange tube, the second heat exchange tube and the third heat exchange tube are respectively provided with a first valve, a second valve and a third valve which are in data connection with the controller;

the left side pipe, the central pipe and the right side pipe are internally provided with a first pressure sensor, a second pressure sensor and a third pressure sensor respectively for detecting the pressures in the left side pipe, the central pipe and the right side pipe, the first pressure sensor, the second pressure sensor and the third pressure sensor are in data connection with a controller, the controller extracts the pressure data of the left side pipe, the right side pipe and the central pipe according to time sequence, the pressure difference or the accumulation of the pressure difference change is obtained through the comparison of the pressure data of adjacent time periods, the pressure difference or the accumulation of the pressure difference change of the first pressure sensor, the second pressure sensor and the third pressure sensor is stored in a database in real time, a one-dimensional deep convolution neural network is adopted to extract data characteristics and perform mode identification, so that the opening and closing of the first valve, the second valve and the third valve are controlled, and the opening and closing of the first valve, the second valve and, Whether the third fluid and the second fluid exchange heat or not.

Preferably, in the fourth step, when the first and third fluids exchange heat and the second fluid does not exchange heat, if the left pipe pressure or the right pipe pressure or the average pressure of the left and right pipes in the previous time period is P1 and the left pipe pressure or the right pipe pressure or the average pressure of the left and right pipes in the next time period is P2, if the difference between P2 and P1 is lower than the threshold, the output detection result is that the first valve and the third valve are controlled to be closed, the second valve is opened, so that the first fluid and the third fluid stop exchanging heat, and the second fluid does not exchange heat; when the heat exchange of the first fluid and the third fluid is stopped and the second fluid exchanges heat, if the central pipe pressure of the previous time period is P1 and the central pipe pressure of the adjacent subsequent time period is P2, if the difference value between P2 and P1 is lower than a threshold value, the detection result is output, the first valve and the third valve are controlled to be opened, the second valve is controlled to be closed, the first fluid and the third fluid exchange heat, and the second fluid stops exchanging heat.

The invention has the following advantages:

1. the invention provides a novel system for intelligently controlling vibration descaling of a heat exchanger, which is based on a theoretical method of machine learning and pattern recognition and is characterized in that accumulated pattern recognition of pressure difference or pressure difference change detected by a pressure sensing element is carried out. The shell-and-tube heat exchanger can realize the periodic frequent vibration of the heat exchange tube, and improves the heating efficiency, thereby realizing good descaling and heating effects.

2. According to the invention, through controlling the opening and closing of the first valve, the second valve and the third valve, on one hand, continuous heat exchange is realized for the shell process flow, and meanwhile, the elastic heat exchange tube can periodically and frequently vibrate, so that good descaling and heat exchange effects are realized.

3. The invention designs that the flowing directions of the first fluid, the third fluid and the second fluid are opposite, and further promotes the flowing of the phase-change fluid, thereby enhancing the heat transfer.

4. The invention designs a layout of a heat exchange component with a novel structure in a shell, optimizes the optimal relation between the parameters of the heat exchange tube and the flow, specific heat and the like of the fluid through a large number of experiments and numerical simulation, and creatively integrates the flow, the specific heat, the temperature and the target temperature of the heat exchange fluid into the size design of the heat exchanger relative to the previous design, thereby further improving the heat exchange efficiency.

5. Through the flowing direction of fluid in the shell, the reasonable change of the internal diameter and the interval of the tube bundle of the heat exchange tube improves the heat exchange efficiency.

Description of the drawings:

fig. 1 is a schematic structural view of a heat exchanger according to the present invention.

FIG. 2 is a schematic sectional view of a heat exchange member according to the present invention.

Fig. 3 is a top view of a heat exchange member.

Fig. 4 is a schematic diagram of a preferred structure of the heat exchanger.

Fig. 5 is another preferred schematic construction of the heat exchanger.

Fig. 6 is a schematic layout of heat exchange components arranged in a circular shell.

Fig. 7 is a schematic diagram of a preferred structure of the heat exchanger.

Fig. 8 is another preferred schematic construction of the heat exchanger.

In the figure: 1. tube group, left tube group 11,

right tube group

12, 21, left tube, 22, right tube, 3, free end, 4, free end, 5, free end, 6, free end, 7, annular tube, 8, center tube, 91-93, heat exchange tube, 10 first orifice, 13 second orifice, left return tube 14, right return tube 15, front tube plate 16, support 17, support 18, rear tube plate 19,

shell

20, 21, shell inlet connection, 22, shell outlet connection, 23, heat exchange component, 24 first valve, 25 second valve, 26 third valve, 27 inlet header, 28 outlet header

Detailed Description

A shell-and-tube heat exchanger, as shown in fig. 1, comprises a shell 20, a heat exchange component 23, a shell-side inlet connecting pipe 21 and a shell-side outlet connecting pipe 22; the heat exchange component 23 is arranged in the shell 20 and fixedly connected to the front tube plate 16 and the rear tube plate 19; the shell side inlet connecting pipe 21 and the shell side outlet connecting pipe 22 are both arranged on the shell 20; fluid enters from the shell side inlet connecting pipe 21, exchanges heat through the heat exchange part and exits from the shell side outlet connecting pipe 22.

Preferably, the heat exchange member extends in a horizontal direction. The heat exchanger is arranged in the horizontal direction.

Fig. 2 shows a top view of a heat exchange part 23, which comprises a central tube 8, a left tube 21, a right tube 22 and tube groups 1, wherein the tube groups 1 comprise a left tube group 11 and a right tube group 12, the left tube group 11 is communicated with the left tube 21 and the central tube 8, the right tube group 12 is communicated with the right tube 22 and the central tube 8, so that the central tube 8, the left tube 21, the right tube 22 and the tube groups 1 form a closed circulation of heating fluid, the left tube 21 and/or the central tube 8 and/or the right tube 22 are filled with phase change fluid, each tube group 1 comprises a plurality of circular tubes 7 in the shape of circular arcs, the ends of the adjacent circular tubes 7 are communicated, so that the plurality of circular tubes 7 form a serial structure, and the ends of the circular tubes 7 form free ends 3-6 of the circular tubes; the central tube comprises a first tube orifice 10 and a second tube orifice 13, the first tube orifice 10 is connected with the inlet of the left tube group 11, the second tube orifice 13 is connected with the inlet of the right tube group 12, the outlet of the left tube group 11 is connected with the left tube 21, and the outlet of the right tube group 12 is connected with the right tube 22; the first orifice 10 and the second orifice 13 are arranged on the same side of the central tube 8. The left tube group and the right tube group are in mirror symmetry along the plane of the axis of the central tube.

The ends of the two ends of the center tube 8, the left tube 21 and the right tube 22 are disposed in the openings of the front and

rear tube plates

16, 19 for fixation. The first orifice 10 and the second orifice 13 are located on the upper side of the central tube 8.

The heat exchanger further comprises a first heat exchange tube 91, a second heat exchange tube 92 and a third heat exchange tube 93, wherein the first heat exchange tube 91 penetrates through the left side tube 21, the second heat exchange tube 92 penetrates through the central tube 8, and the third heat exchange tube 93 penetrates through the right side tube 22. The first heat exchange pipe 91, the second heat exchange pipe 92, and the third heat exchange pipe 93 flow a first fluid, a second fluid, and a third fluid, respectively. The first fluid, the second fluid, the third fluid and the shell side fluid can exchange heat among the four fluids. The four fluid heat sources can be 1-3, and the rest of the fluid is a cold source, or the cold source can be 1-3, and the rest of the fluid is a heat source.

As a preferred example of the heat exchange, for example, the heat exchange process is as follows:

the first fluid is a heat source, the second fluid, the third fluid and the shell pass fluid are cold sources, phase change fluid in the heat exchange component is subjected to phase change through heat exchange of the first fluid, so that the shell pass fluid is subjected to heat exchange through the annular pipe 7, meanwhile, vapor phase fluid enters the central pipe and the right side pipe to exchange heat with the second fluid and the third fluid, and condensed fluid after heat exchange returns to the right side pipe through the return pipe, so that heat exchange of the four fluids is realized.

Preferably, the third fluid and the second fluid are heat sources, the first fluid and the shell-side fluid are cold sources, and the phase-change fluid in the heat exchange part is subjected to phase change through heat exchange of the second fluid and the third fluid, so that the shell-side fluid is radiated outwards through the annular pipe 7, meanwhile, the vapor-phase fluid enters the left side pipe and exchanges heat with the first fluid, and the condensed fluid after heat exchange returns to the right pipe box through the return pipe, so that the four-fluid heat exchange is realized.

Preferably, the shell-side fluid is a heat source, the first fluid, the second fluid and the third fluid are cold sources, and the heat exchange of the shell-side fluid enables the fluid in the heat exchange component to absorb heat and exchange heat with the first fluid, the second fluid and the third fluid, so that the four-fluid heat exchange is realized.

Preferably, the first fluid and the third fluid are cold sources, the second fluid and the shell-side fluid are heat sources, and the heat exchange is realized through the second fluid and the shell-side fluid, so that the four-fluid heat exchange is realized.

Preferably, the second fluid is a cold source, the first fluid, the third fluid and the shell-side fluid are heat sources, and the second fluid is subjected to heat exchange through heat exchange of the first fluid, the third fluid and the shell-side fluid, so that four-fluid heat exchange is realized.

Preferably, the shell-side fluid is a cold source, the first fluid, the second fluid and the third fluid are heat sources, and the four-fluid heat exchange is realized by exchanging heat between the first fluid, the second fluid and the third fluid and the shell-side fluid.

Preferably, the first heat exchange tube, the second heat exchange tube and the third heat exchange tube have the same inner diameter.

Preferably, a left return pipe 14 is arranged between the left pipe 21 and the central pipe 8, and a right return pipe 14 is arranged between the right pipe 22 and the central pipe 8. Preferably, the return pipe is arranged at the end of the central pipe. Both ends of the central tube are preferred.

Preferably, the fluid is a phase change fluid, preferably a vapour-liquid phase change fluid.

The following description focuses on the case where the shell-side fluid is the heat sink and the first fluid, the second fluid, and the third fluid are the heat sources.

The fluid exchanges heat and evaporates in the central pipe 8, flows to the left and

right headers

21, 22 along the annular tube bundle, and the fluid can produce volume expansion after being heated, thereby forming steam, and the volume of steam is far greater than water, therefore the steam that forms can carry out the flow of quick impact formula in the coil pipe. Because of volume expansion and steam flow, the free end of the annular tube can be induced to vibrate, the vibration is transmitted to the surrounding heat exchange fluid by the free end of the heat exchange tube in the vibration process, and the fluid can also generate disturbance, so that the surrounding heat exchange fluid forms disturbance flow, a boundary layer is damaged, and the purpose of enhancing heat transfer is realized. The fluid is condensed and released heat in the left and right side pipes and then flows back to the central pipe through the return pipe. On the contrary, the fluid can exchange heat in the left and right side pipes, then enters the central pipe, is condensed and returns to the left and right side pipes through the return pipe for circulation.

According to the invention, the prior art is improved, and the condensation (evaporation) collecting pipe and the pipe groups are respectively arranged into two pipes which are distributed on the left side and the right side, so that the pipe groups distributed on the left side and the right side can perform vibration heat exchange descaling, the heat exchange vibration area is enlarged, the vibration is more uniform, the heat exchange effect is more uniform, the heat exchange area is increased, and the heat exchange and descaling effects are enhanced.

The flow rate in the present application is a flow rate per unit time, not specifically described. The unit is m 3/s.

Preferably, as shown in fig. 7 and 8, the first valve 24, the second valve 25 and the third valve 26 are arranged at the inlets of the first heat exchange pipe 91, the second heat exchange pipe 92 and the third heat exchange pipe 93, the first valve 24, the second valve 25 and the third valve 26 are in data connection with a controller, and the controller controls the opening and closing and the opening of the first valve 24, the second valve 25 and the third valve 26 for controlling the flow of the heat exchange fluid entering the first heat exchange pipe 91, the second heat exchange pipe 92 and the third heat exchange pipe 93.

It has been found in research and practice that the heat exchange of the heat source with continuous power stability can cause the fluid forming stability of the internal heat exchange components, i.e. the fluid is not flowing or has little fluidity, or the flow rate is stable, and the vibration performance of the annular tubes 7 is greatly weakened, thereby affecting the descaling of the left tube group 11 and the right tube group 12 and the heat exchange efficiency. There is therefore a need for improvements to the heat exchangers described above as follows.

In the prior application of the inventor, a periodic heat exchange mode is provided, and the vibration of the annular tube is continuously promoted through the periodic heat exchange mode, so that the heat exchange efficiency and the descaling effect are improved. However, adjusting the vibration of the tube bundle with a fixed periodic variation can lead to hysteresis and too long or too short a period. Therefore, the invention improves the previous application and intelligently controls the vibration, so that the fluid in the fluid can realize frequent vibration, and good descaling and heat exchange effects are realized.

Aiming at the defects in the technology researched in the prior art, the invention provides a novel heat exchanger capable of intelligently controlling vibration. The heat exchanger can improve the heat exchange efficiency, thereby realizing good descaling and heat exchange effects.

Self-regulation vibration based on pressure

Preferably, a first pressure sensor, a second pressure sensor and a third pressure sensor are respectively arranged in the left side pipe 21, the central pipe 8 and the right side pipe 22 and used for detecting the pressures in the left side pipe, the central pipe and the right side pipe, the first pressure sensor, the second pressure sensor and the third pressure sensor are in data connection with a controller, the controller extracts the pressure data of the left side pipe, the right side pipe and the central pipe according to time sequence and obtains the pressure difference or the accumulation of the pressure difference change through the comparison of the pressure data of adjacent time periods, the accumulated data of the pressure difference or the pressure difference change of the first pressure sensor, the second pressure sensor and the third pressure sensor are stored in a database in real time, a one-dimensional deep convolution neural network is adopted to extract data characteristics and carry out pattern recognition, thereby controlling the opening and closing of the first valve 24, the second valve 25 and the third valve 26, thereby controlling whether the first fluid, the third fluid and the second fluid exchange heat or not.

The pressure-based autonomous adjustment vibration pattern recognition includes the steps of:

1. preparing data: and reexamining and checking the pressure data in the database, correcting missing data, invalid data and inconsistent data, and ensuring the correctness and logical consistency of the data.

2. Generating a data set: the prepared data is divided into training set/training set labels, detection set/detection set labels.

3. Network training: inputting the training set data into a convolution neural network, continuously performing convolution and pooling to obtain a characteristic vector, and sending the characteristic vector into a full-connection network. And obtaining a network error by calculating the output of the network and a training set label, and continuously correcting the network weight, the bias, the convolution coefficient and the pooling coefficient by using an error back propagation algorithm to enable the error to meet the set precision requirement, thereby finishing the network training.

4. Network detection: and inputting the detection set data into the trained network, and outputting a detection result label.

5. The heat exchanger operates: and controlling the opening and closing of the first valve 24, the second valve 25 and the third valve 26 according to the detection result label to remove the scale.

The invention provides a novel system for intelligently controlling vibration descaling of a heat exchange device, which is based on a theoretical method of machine learning and pattern recognition, utilizes accumulated data of pressure difference or pressure difference change with time correlation in a centralized heat exchanger real-time monitoring system according to different operating conditions of a heat exchanger, designs corresponding working states of the heat exchanger (the opening and closing states of a first valve 24, a second valve 25 and a third valve 26), and trains a deep convolutional neural network by using a large amount of pressure data so as to control heat exchange descaling of the heat exchanger.

Preferably, the data preparation step specifically includes the following processing:

1) processing missing data: missing values in the database may occur due to a failure of the network transmission. For the missing data value, adopting an estimation method and replacing the missing value with the sample mean value;

2) processing invalid data: the pressure data in the database may have invalid values, such as negative values or values exceeding a theoretical maximum value, due to a failure of the sensor, and these values are deleted from the database;

3) processing inconsistent data: the inconsistent data is checked by means of an integrity constraint mechanism of the database management system, and then corrected by referring to corresponding data values in the database. Preferably, in the heat exchanger, the heating pipe pressure opened by the first valve 24, the second valve 25 and the third valve 26 is necessarily higher than the non-heating pipe pressure, and if the heating pipe pressure in the database is lower than the non-heating pipe pressure, a user error prompt can be given by means of a check constraint mechanism in the integrity constraint of the database management system, and the user replaces the pressure data value of the inconsistent data with the estimated data or the corresponding critical pressure data value according to the error prompt.

Preferably, the step of generating a data set comprises the steps of:

1) generating training set data and labels: and reading the pressure data values of the corresponding working conditions from the database according to different operating conditions of the heat collecting device, and generating training set data and working condition labels under various working condition states. Preferably, in a specific application, the operation condition is divided into a label 1, the first valve and the third valve are closed, the second valve is opened, and a label 2, the first valve and the third valve are opened, and the second valve is closed. Automatically generating working condition labels by a program according to different working conditions;

preferably, the data includes data indicating that the evaporation of the fluid within the internal heat exchange component is substantially saturated or stable under different operating conditions. The working condition comprises at least one of valve opening, heat exchange fluid temperature and the like.

2) Generating detection set data and labels: and reading the accumulated data value of the pressure difference or the pressure difference change corresponding to the working condition from the database according to different operating conditions of the heat exchanger, and generating detection set data and working condition labels under various working condition states. The working condition labels are the same as the working condition labels of the training set and are automatically generated by a program according to the running working conditions.

Preferably, it is determined whether or not the evaporation of the fluid inside the left tank, the right tank (the first valve and the third valve are opened), or the middle tank (the second valve is opened) is saturated or stabilized (reaches or exceeds a certain pressure). For example, the left and right headers are not saturated or stable, labeled 11 for saturation or stability, labeled 12 for saturation or stability, the middle header is not saturated or stable, labeled 21 for saturation or stability, and labeled 22.

The network training comprises the following specific steps:

1) reading a group of training set data d, wherein the size of the training set data d is [ Mx 1 xN ], M represents the size of a training batch, and 1 xN represents one-dimensional training data;

2) and performing a first convolution operation on the read training data to obtain a feature map t. Initializing coefficients of a convolution kernel g, and setting the size of g as [ P × 1 × Q ], wherein P represents the number of convolution kernels, [1 × Q ] represents the size of the convolution kernels, the obtained convolution result is t ═ Σ (d × g), and the size of a feature map is [ M × 1 × N × Q ];

3) and performing maximum pooling operation on the feature map t obtained by the convolution operation to obtain a feature map z. Initializing a pooling coefficient, wherein the given pooling step length is p, the size of a pooling window is k, the size of a finally obtained feature map z is [ Mx1 x (N/p). times.Q ], and the data dimensionality is reduced in a pooling process;

4) repeating the steps 2) -3), repeatedly performing convolution and pooling operation to obtain a feature vector x, and finishing the feature extraction process of the convolutional neural network;

5) initializing a weight matrix w and an offset b of the full-connection network, sending the extracted eigenvector x into the full-connection network, and calculating with the weight matrix w and the offset b to obtain a network output y ═ sigma (wxx + b);

6) subtracting the training set label l from the output y obtained by the network to obtain a network error e which is y-l, carrying out derivation on the network error, and sequentially correcting the weight w, the bias b, the pooling coefficients of each layer and the convolution coefficients of each layer of the fully-connected network by utilizing the derivative back propagation;

7) and repeating the process until the network error e meets the precision requirement, finishing the network training process, and generating a convolutional neural network model.

When the first valve and the third valve are opened and the second valve is closed, the data are measured by the first pressure sensor and the third pressure sensor. Preferably, the average of the first and third pressures is used. When the first valve and the third valve are closed and the second valve is opened, the data is the data measured by the second pressure sensor.

The network detection steps are as follows:

1) loading the trained convolutional neural network model, wherein the convolutional kernel coefficient, the pooling coefficient, the network weight w and the bias b of the convolutional neural network are trained;

2) and inputting the detection data set into the trained convolutional neural network, and outputting a detection result. The type of run can be determined, for example, based on the output tag. For example, 1 represents the first valve, the third valve open, the second valve closed, 2 represents the first valve, the third valve closed, the second valve open, and so on.

The invention provides a new method for controlling heat exchange of a heat exchanger, which makes full use of online monitoring data of the heat exchanger, and has the advantages of high detection speed and low cost.

The invention organically integrates the data processing technology, machine learning and pattern recognition theory, and can improve the accuracy of the operation of the heat exchanger.

The working process of the specific convolutional neural network is as follows:

1) inputting a group of training set data d, wherein the size of the training set data d is [ M multiplied by 1 multiplied by N ], M represents the size of the training batch, and 1 multiplied by N represents one-dimensional training data;

3) and performing maximum pooling operation on the feature map t obtained by the convolution operation to obtain a feature map z. Initializing a pooling coefficient, setting a pooling step length as p, setting a pooling window size as k, and reducing data dimensionality in a pooling process, wherein the size of a finally obtained feature map z is [ MX 1X (N/p) XQ ];

4) repeating the steps 2) -3), and repeatedly performing convolution and pooling operation to obtain a feature vector;

through the mode recognition of the pressure difference or the accumulated pressure difference change detected by the pressure sensing element, the invention can design a corresponding operation mode by utilizing the pressure data in the heat exchanger real-time monitoring system based on the theoretical method of machine memory and mode recognition according to different operation conditions of the heat exchanger, and train the deep convolution neural network by using a large amount of pressure difference or accumulated pressure difference change data, thereby descaling the heat exchange part and improving the heat utilization effect and descaling effect. The shell-and-tube heat exchanger can realize the periodic frequent vibration of the heat exchange tube, and improves the heating efficiency, thereby realizing good descaling and heating effects.

The invention can be based on the theoretical method of machine memory and mode recognition, through the accumulation of the pressure difference or the pressure difference change detected by the pressure sensing element, under the condition of meeting a certain pressure difference or accumulation of the pressure difference change, the evaporation of the fluid in the left side pipe, the right side pipe or the central pipe is basically saturated, and the volume of the internal fluid is not changed greatly basically. Therefore, new fluid is started to perform alternate heat exchange by detecting the pressure change in the left side pipe, the right side pipe and the central pipe, and the heat exchange effect and the descaling effect are improved.

The invention can be based on the theoretical method of machine memory and pattern recognition, so that the detection and judgment results are more accurate.

The heat exchanger operation step comprises controlling the opening and closing of the first valve 24, the second valve 25 and the third valve 26 according to the output detection result label, thereby controlling whether the first fluid, the third fluid and the second fluid exchange heat.

Through the pressure difference of the previous and subsequent time periods or the accumulated pressure difference detected by the pressure sensing element, the evaporation of the fluid inside can be judged to be basically saturated through the pressure difference, and the volume of the fluid inside is basically not changed greatly. So that the fluid undergoes volume reduction to thereby realize vibration. When the pressure difference is reduced to a certain degree, the internal fluid starts to enter a stable state again, and at the moment, the fluid needs to be heated so as to be evaporated and expanded again, so that the electric heater needs to be started for heating.

The stable state of the fluid is judged according to the pressure difference or the accumulation of the pressure difference change, so that the result is more accurate, and the problem of error increase caused by aging due to the running time problem is solved.

Preferably, in step 4, when the first and third fluids exchange heat and the second fluid does not exchange heat, if the left pipe pressure or the right pipe pressure or the average pressure of the left and right pipes in the previous time period is P1 and the left pipe pressure or the right pipe pressure or the average pressure of the left and right pipes in the next time period is P2, if the difference between P2 and P1 is lower than the threshold, the output detection result flag indicates that the first valve and the third valve are controlled to be closed and the second valve is opened, so that the first fluid and the third fluid stop exchanging heat and the second fluid does not exchange heat; when the heat exchange of the first fluid and the third fluid is stopped and the second fluid exchanges heat, if the central pipe pressure of the previous time period is P1 and the central pipe pressure of the adjacent subsequent time period is P2, if the difference value between P2 and P1 is lower than the threshold value, the output detection result label controls the first valve and the third valve to be opened, the second valve is closed, so that the first fluid and the third fluid exchange heat, and the second fluid stops exchanging heat.

The operation state of the valve is determined according to different conditions through the difference of the heating pressure of different side pipes.

Preferably, when the first and third fluids exchange heat and the second fluid does not exchange heat, if the left pipe pressure or the right pipe pressure or the average pressure of the left and right pipes in the previous period is P1, and the left pipe pressure or the right pipe pressure or the average pressure of the left and right pipes in the next period is P2, if P1 is P2, the heating is judged according to the following conditions:

if P1 is greater than the pressure of the first data, outputting a detection result label that the first valve and the third valve are controlled to be closed, and the second valve is opened, so that the heat exchange of the first fluid and the third fluid is stopped, and the heat exchange of the second fluid is carried out; wherein the first data is greater than the pressure of the phase change fluid after the phase change; preferably the first data is a pressure at which the phase change fluid is substantially phase-changed;

if the pressure P1 is less than or equal to the pressure of the second data, the output detection result label is to control the first valve and the third valve to continue to open, the second valve continues to close, so that the first fluid and the third fluid continue to exchange heat, and the second fluid continues to stop exchanging heat, wherein the pressure of the second data is less than or equal to the pressure at which the phase change fluid does not change phase.

The first data is pressure data in a fully heated state, and the second data is pressure data in the absence of heating or in the beginning of heating. Through the judgment of the pressure, the operation state of the valve is determined according to different conditions, and overheating or operation starting is avoided.

Preferably, when the first and third fluids do not exchange heat and the second fluid exchanges heat, if the pressure of the central tube in the previous time period is P1 and the pressure of the central tube in the next subsequent time period is P2, if P1 is P2, the heating is judged according to the following conditions:

if P1 is greater than the pressure of the first data, outputting a detection result label that the first valve and the third valve are controlled to be opened and the second valve is controlled to be closed; wherein the first data is greater than the pressure of the phase change fluid after the phase change; preferably the first data is a pressure at which the phase change fluid is substantially phase-changed;

if P1 is less than or equal to the pressure of the second data, the output detection result label is to control the first valve and the third valve to continue to close, and the second valve to continue to open, wherein the second data is less than or equal to the pressure at which the phase change fluid does not change phase.

The first data is pressure data in a fully heated state, and the second data is pressure data in the absence of heating or in the beginning of heating. Through the judgment of the pressure, the operation state of the valve is determined according to different conditions through the judgment of the pressure, and overheating or operation starting is avoided.

Preferably, the left side pipe, the right side pipe and the central pipe are respectively provided with a plurality of n pressure sensing elements, and the pressure P in the current time period is calculated in sequence_iPressure Q of the preceding period_i-1Difference D of_i＝P_i-Q_i-1And for n pressure differences D_iPerforming arithmetic cumulative summation

And 5, when the value of Y is lower than the set threshold value, controlling the opening and closing of the first valve, the second valve and the third valve according to the output detection result label.

Preferably, when the first and third valves are opened and the second valve is closed and is lower than the threshold value, the output detection result flag controls the first and third valves to be closed and the controller controls the second valve to be opened.

Preferably, when the first and third electric heaters are closed and the second valve is opened, and the output detection result is lower than a threshold value, the output detection result label controls the first and third valves to be opened and the controller controls the second valve to be closed.

The operation state of the valve is determined according to different conditions through the difference of the heating pressure of different pipe boxes.

Preferably, if Y is 0, heating is judged according to the following:

when the first and third valves are opened and the second valve is closed, or when the first and third valves are closed and the second valve is opened:

if P is_iIf the arithmetic mean of the first data is larger than the pressure of the first data, the output detection result label controls the opened valve to be closed and the closed valve to be opened when the pressure is lower than the threshold value; wherein the first data is greater than the pressure of the phase change fluid after the phase change; preferably the pressure at which the phase change fluid substantially changes phase;

if P is_iIs less than the pressure of the second data, and is less than the threshold value, the output detection result label controls the opened valve to continue to open and the closed valve to continue to close, wherein the second data is less than or equal to the pressure at which the phase change fluid does not undergo the phase change.

The first data is pressure data in a fully heated state, and the second data is pressure data in the absence of heating or in the beginning of heating. Through the judgment of the pressure, the operation state of the valve is determined according to different conditions, so that alternate heating is realized.

Preferably, the period of time for measuring the pressure is 1 to 10 minutes, preferably 3 to 6 minutes, and further preferably 4 minutes.

Preferably, the threshold is 100-1000pa, preferably 500 pa.

Preferably, the pressure value may be an average pressure value over a period of the time period. The pressure at a certain moment in time may also be used. For example, preferably both are pressures at the end of the time period.

Independently adjusting vibration based on temperature

Preferably, a first temperature sensor, a second temperature sensor and a third temperature sensor are respectively arranged in the left side tube 21, the central tube 8 and the right side tube 22 and used for detecting the temperature in the left side tube, the central tube and the right side tube, the first temperature sensor, the second temperature sensor and the third temperature sensor are in data connection with a controller, the controller extracts the temperature data of the left side tube, the right side tube and the central tube according to time sequence, the temperature difference or the accumulation of the temperature difference change is obtained by comparing the temperature data of adjacent time periods, the temperature difference or the accumulation of the temperature difference change of the first temperature sensor, the second temperature sensor and the third temperature sensor are stored in a database in real time, the data characteristics are extracted by adopting a one-dimensional depth convolution neural network, pattern recognition is carried out, and the opening and closing of the first valve 24, the second valve 25 and the third valve 26 are controlled, thereby controlling whether the first fluid, the third fluid and the second fluid exchange heat or not.

The temperature-based self-adjusting vibration pattern recognition comprises the following steps:

1. preparing data: and reexamining and checking the temperature data in the database, correcting missing data, invalid data and inconsistent data, and ensuring the correctness and logical consistency of the data.

The invention provides a novel system for intelligently controlling vibration descaling of a heat exchange device, which is based on a theoretical method of machine learning and pattern recognition, utilizes accumulated data of temperature difference or temperature difference change with time correlation in a centralized heat exchanger real-time monitoring system according to different operating conditions of a heat exchanger, designs corresponding working states of the heat exchanger (the opening and closing states of a first valve 24, a second valve 25 and a third valve 26), and trains a deep convolutional neural network by using a large amount of temperature data so as to control heat exchange and descaling of the heat exchanger.

2) processing invalid data: the temperature data in the database may have invalid values, such as negative values or values exceeding a theoretical maximum value, due to a failure of the sensor, and these values are deleted from the database;

3) processing inconsistent data: the inconsistent data is checked by means of an integrity constraint mechanism of the database management system, and then corrected by referring to corresponding data values in the database. Preferably, in the heat exchanger, the temperature of the heating pipe opened by the first valve 24, the second valve 25 and the third valve 26 is necessarily higher than the temperature of the non-heating pipe, if the temperature of the heating pipe in the database is lower than the temperature of the non-heating pipe, a user error prompt can be given by means of a check constraint mechanism in the integrity constraint of the database management system, and the user replaces the temperature data value of the inconsistent data with the estimated data or the corresponding critical temperature data value according to the error prompt.

Preferably, the step of generating a data set comprises the steps of:

1) generating training set data and labels: and reading the temperature data values of the corresponding working conditions from the database according to different operating conditions of the heat collecting device, and generating training set data and working condition labels under various working condition states. Preferably, in a specific application, the operation condition is divided into a label 1, the first valve and the third valve are closed, the second valve is opened, and a label 2, the first valve and the third valve are opened, and the second valve is closed. Automatically generating working condition labels by a program according to different working conditions;

2) Generating detection set data and labels: and reading the temperature difference or the accumulated data value of the temperature difference change corresponding to the working condition from the database according to different operating conditions of the heat exchanger, and generating detection set data and working condition labels under various working condition states. The working condition labels are the same as the working condition labels of the training set and are automatically generated by a program according to the running working conditions.

Preferably, it is determined whether or not the evaporation of the fluid inside the left tank, the right tank (the first valve and the third valve are opened), or the middle tank (the second valve is opened) is saturated or stabilized (reaches or exceeds a certain temperature). For example, the left and right headers are not saturated or stable, labeled 11 for saturation or stability, labeled 12 for saturation or stability, the middle header is not saturated or stable, labeled 21 for saturation or stability, and labeled 22.

The network training comprises the following specific steps:

When the first valve and the third valve are opened and the second valve is closed, the data are measured by the first temperature sensor and the third temperature sensor. Preferably, the average of the first and third temperatures is used. When the first valve and the third valve are closed and the second valve is opened, the data is the data measured by the second temperature sensor.

The network detection steps are as follows:

The working process of the specific convolutional neural network is as follows:

through the mode recognition of the temperature difference or the accumulated temperature difference change detected by the temperature sensing element, the invention can design a corresponding operation mode by utilizing the temperature data in the heat exchanger real-time monitoring system according to different operation conditions of the heat exchanger based on the theoretical method of machine memory and mode recognition, and train the deep convolutional neural network by using a large amount of accumulated temperature difference or temperature difference change data, thereby descaling the heat exchange part and improving the heat utilization effect and descaling effect. The shell-and-tube heat exchanger can realize the periodic frequent vibration of the heat exchange tube, and improves the heating efficiency, thereby realizing good descaling and heating effects.

The invention can be based on the theoretical method of machine memory and mode recognition, through the accumulation of the temperature difference or the temperature difference change detected by the temperature sensing element, under the condition of meeting a certain temperature difference or the accumulation of the temperature difference change, the evaporation of the fluid in the left side pipe, the right side pipe or the central pipe is basically saturated, and the volume of the internal fluid is not changed basically, under the condition, the internal fluid is relatively stable, the vibration of the pipe bundle at the moment is reduced, so that the adjustment is needed, the heat exchange component is changed, and the fluid flows towards different directions. Therefore, new fluid is started to perform alternate heat exchange by detecting the temperature change in the left side pipe, the right side pipe and the central pipe, and the heat exchange effect and the descaling effect are improved.

The temperature difference or the accumulated temperature difference of the previous time period and the later time period detected by the temperature sensing element can be used for judging that the evaporation of the fluid inside is basically saturated and the volume of the fluid inside is not changed greatly. So that the fluid undergoes volume reduction to thereby realize vibration. When the temperature difference is reduced to a certain degree, the internal fluid starts to enter a stable state again, and the fluid needs to be heated to evaporate and expand again, so that the electric heater needs to be started for heating.

The stable state of the fluid is judged according to the temperature difference or the accumulation of the temperature difference change, so that the result is more accurate, and the problem of error increase caused by aging due to the problem of operation time is solved.

Preferably, in step 4, when the first and third fluids exchange heat and the second fluid does not exchange heat, if the left tube temperature or the right tube temperature or the average temperature of the left and right tubes in the previous period is T1 and the left tube temperature or the right tube temperature or the average temperature of the left and right tubes in the next period is T2, if the difference between T2 and T1 is lower than the threshold, the output detection result flag indicates that the first valve and the third valve are closed and the second valve is opened, so that the first and third fluids stop exchanging heat and the second fluid exchanges heat; when the first fluid and the third fluid stop exchanging heat and the second fluid exchanges heat, if the temperature of the central tube in the previous time period is T1 and the temperature of the central tube in the next time period is T2, and if the difference value between T2 and T1 is lower than the threshold value, the output detection result label controls the first valve and the third valve to be opened and the second valve to be closed, so that the first fluid and the third fluid exchange heat and the second fluid stops exchanging heat.

The operating state of the valve is determined according to different conditions through the difference of the heating temperatures of different side pipes.

Preferably, when the first and third fluids exchange heat and the second fluid does not exchange heat, if the left tube temperature or the right tube temperature or the average temperature of the left and right tubes in the previous period is T1, and the left tube temperature or the right tube temperature or the average temperature of the left and right tubes in the next subsequent period is T2, if T1 is T2, the heating is determined according to the following conditions:

if T1 is greater than the temperature of the first data, outputting a detection result label that the first valve and the third valve are controlled to be closed, and the second valve is opened, so that the heat exchange of the first fluid and the third fluid is stopped, and the heat exchange of the second fluid is carried out; wherein the first data is greater than the temperature of the phase change fluid after the phase change; preferably the first data is a temperature at which the phase change fluid substantially changes phase;

if T1 is less than or equal to the temperature of the second data, the output detection result label is to control the first valve and the third valve to continue to open, and the second valve continues to close, so that the first fluid and the third fluid continue to exchange heat, and the second fluid continues to stop exchanging heat, wherein the second data is less than or equal to the temperature at which the phase change fluid does not change phase.

The first data is temperature data of a sufficiently heated state, and the second data is temperature data of no heating or temperature data of the beginning of heating. Through the judgment of the temperature, the operation state of the valve is determined according to different conditions, and overheating or operation starting is avoided.

Preferably, when the first and third fluids do not exchange heat and the second fluid exchanges heat, if the temperature of the central tube in the previous time period is T1 and the temperature of the central tube in the adjacent subsequent time period is T2, if T1 is T2, the heating is judged according to the following conditions:

if T1 is greater than the temperature of the first data, the output detection result label is that the first valve and the third valve are controlled to be opened, and the second valve is controlled to be closed; wherein the first data is greater than the temperature of the phase change fluid after the phase change; preferably the first data is a temperature at which the phase change fluid substantially changes phase;

if T1 is less than or equal to the temperature of the second data, the output detection result label is to control the first valve and the third valve to be closed continuously, and the second valve is opened continuously, wherein the second data is less than or equal to the temperature at which the phase change fluid does not change phase.

The first data is temperature data of a sufficiently heated state, and the second data is temperature data of no heating or temperature data of the beginning of heating. Through the judgment of the temperature, the operation state of the valve is determined according to different conditions through the judgment of the temperature, and overheating or operation starting is avoided.

Preferably, the left side pipe, the right side pipe and the central pipe are respectively provided with a plurality of n temperature sensing elements, and the temperature P of the current time period is calculated in sequence_iTemperature Q of the preceding time period_i-1Difference D of_i＝P_i-Q_i-1And for n temperature differences D_iPerforming arithmetic cumulative summation

The operation state of the valve is determined according to different conditions through the difference of the heating temperatures of different pipe boxes.

Preferably, if Y is 0, heating is judged according to the following:

if P is_iIf the arithmetic mean of the first data is higher than the temperature of the first data, the output detection result label controls the opened valve to be closed and the closed valve to be opened when the temperature of the first data is lower than the threshold value; wherein the first data is greater than the temperature of the phase change fluid after the phase change; preferably the temperature at which the phase change fluid substantially changes phase;

if P is_iIs less than the temperature of the second data, and is less than the threshold value, the output detection result label controls the opened valve to continue to open and the closed valve to continue to close, wherein the second data is less than or equal to the temperature at which the phase change of the phase-change fluid does not occur.

The first data is temperature data of a sufficiently heated state, and the second data is temperature data of no heating or temperature data of the beginning of heating. Through the judgment of the temperature, the operation state of the valve is determined according to different conditions, so that alternate heating is realized.

Preferably, the period of time for measuring the temperature is 1 to 10 minutes, preferably 3 to 6 minutes, and further preferably 4 minutes.

Preferably, the temperature value may be an average temperature value over a period of the time period. The temperature at a certain moment in time may also be used. For example, preferably both are temperatures at the end of the time period.

Preferably, the average temperatures of the first fluid, the second fluid and the third fluid are the same, the flow rate per unit time of the first fluid per unit time is equal to the flow rate per unit time of the third fluid, and the flow rate per unit time of the first fluid per unit time is 0.5 times the flow rate per unit time of the second fluid. The average temperature is an average of the fluid inlet temperature and the fluid outlet temperature.

Preferably, the first fluid, the second fluid and the third fluid are the same fluid.

As shown preferably in fig. 4, the first fluid, the second fluid and the third fluid have a common inlet header 27 and outlet header 28. Fluid enters the inlet header, enters the first heat exchange tube and the second heat exchange tube through the inlet header for heat exchange, and then flows out through the outlet header.

As shown preferably in fig. 5, the first, second and third fluids have respective inlet and outlet headers 29-30 and 31-32, respectively. The fluid enters the respective inlet headers, then enters the first heat exchange tubes, the second heat exchange tubes and the third heat exchange tubes through the inlet headers for heat exchange, and then flows out through the respective outlet headers.

Preferably, the bottom parts of the right channel box and the left channel box are provided with return pipes communicated with the central pipe, so that the fluid condensed in the first channel box and the second channel box can rapidly flow.

Preferably, the pipe diameter of the right side pipe is equal to that of the left side pipe. The pipe diameters of the right side pipe and the left side pipe are equal, so that the fluid can be ensured to be subjected to phase change in the first box body and keep the same transmission speed with the left pipe box.

Through the alternating heat exchange of the three fluids, the frequent vibration of the elastic coil can be realized, so that good descaling and heat exchange effects are realized, and the heat exchange power is basically the same in time.

Preferably, the annular pipes of the left pipe group are distributed by taking the axis of the left pipe as the center of a circle, and the annular pipes of the right pipe group are distributed by taking the axis of the right pipe as the center of a circle. The left side pipe and the right side pipe are arranged as circle centers, so that the distribution of the annular pipes can be better ensured, and the vibration and the heat exchange are uniform.

Preferably, the tube group is plural.

Preferably, the center tube 8, the left tube 21, and the right tube 22 are provided along the longitudinal direction.

Preferably, the left tube group 21 and the right tube group 22 are staggered in the longitudinal direction, as shown in fig. 3. Through the staggered distribution, can make to vibrate heat transfer and scale removal on different length for the vibration is more even, strengthens heat transfer and scale removal effect.

Preferably, the tube group 2 is provided in plural (for example, the same side (left side or right side)) along the length direction of the center tube 8, and the tube diameter of the tube group 2 (for example, the same side (left side or right side)) becomes larger along the flow direction of the fluid in the shell side.

Preferably, the pipe diameter of the annular pipe of the pipe group (for example, the same side (left side or right side)) is increased along the flowing direction of the fluid in the shell side.

The pipe diameter range through the heat exchange tube increases, can guarantee that shell side fluid outlet position fully carries out the heat transfer, forms the heat transfer effect like the adverse current, further strengthens the heat transfer effect moreover for whole vibration effect is even, and the heat transfer effect increases, further improves heat transfer effect and scale removal effect. Experiments show that better heat exchange effect and descaling effect can be achieved by adopting the structural design.

Preferably, the tube group on the same side (left side or right side) is provided in plural along the length direction of the center tube 8, and the distance between the adjacent tube groups on the same side (left side or right side) becomes smaller along the flow direction of the fluid in the shell side.

Preferably, the spacing between the tube banks on the same side (left or right) in the direction of fluid flow in the shell side is increased by a decreasing amount.

The interval amplitude through the heat exchange tube increases, can guarantee that shell side fluid outlet position fully carries out the heat transfer, forms the heat transfer effect like the adverse current, further strengthens the heat transfer effect moreover for the whole vibration effect is even, and the heat transfer effect increases, further improves heat transfer effect and scale removal effect. Experiments show that better heat exchange effect and descaling effect can be achieved by adopting the structural design.

In tests it was found that the pipe diameters, distances and pipe diameters of the left side pipe 21, the right side pipe 22, the central pipe 8 and the pipe diameters of the ring pipes can have an influence on the heat exchange efficiency and the uniformity. If the distance between the collector is too big, then heat exchange efficiency is too poor, and the distance between the ring shape pipe is too little, then the ring shape pipe distributes too closely, also can influence heat exchange efficiency, and the pipe diameter size of collector and heat exchange tube influences the volume of the liquid or the steam that holds, then can exert an influence to the vibration of free end to influence the heat transfer. Therefore, the pipe diameters and distances of the left pipe 21, the right pipe 22, the central pipe 8 and the pipe diameters of the ring pipes have a certain relationship.

The invention provides an optimal size relation summarized by numerical simulation and test data of a plurality of heat pipes with different sizes. Starting from the maximum heat exchange amount in the heat exchange effect, nearly 200 forms are calculated. The dimensional relationship is as follows:

the distance between the center of the central tube 8 and the center of the left tube 21 is equal to the distance between the center of the central tube 8 and the center of the right tube 21, L, the distance between the center of the left tube 21 and the center of the right tube 21 is M, the tube diameters of the left tube 21, the central tube 8 and the right tube 22 are R, the radius of the axis of the innermost annular tube in the annular tubes is R1, and the radius of the axis of the outermost annular tube is R2, so that the following requirements are met:

R1/R2 ═ a × Ln (R/M) + b; wherein a, b are parameters, Ln is a logarithmic function, wherein 0.5785 < a < 0.5805, 1.6615 < b < 1.6625; preferably, a is 0.579 and b is 1.6621.

Preferably, 35 < R < 61 mm; l is more than 114 and less than 190 mm; 69 < R1 < 121mm, 119 < R2 < 201 mm. M ═ 2L.

Preferably, the number of annular tubes of the tube set is 3-5, preferably 3 or 4.

Preferably, 0.55 < R1/R2 < 0.62; R/L is more than 0.3 and less than 0.33.

Preferably, 0.583 < R1/R2 < 0.615; R/L is more than 0.315 and less than 0.332.

Preferably, the radius of the annular tube is preferably 10-40 mm; preferably 15 to 35mm, more preferably 20 to 30 mm.

Preferably, the centers of the left tube 21, the right tube 22 and the center tube 8 are on a straight line.

Preferably, the arc between the ends of the free ends 3, 4 around the centre axis of the left tube is 95-130 degrees, preferably 120 degrees. The same applies to the curvature of the free ends 5, 6 and the free ends 3, 4. Through the design of the preferable included angle, the vibration of the free end is optimal, and therefore the heat exchange efficiency is optimal.

Preferably, the heat exchange component can be used as an immersed heat exchange assembly, heat exchange fluid immersed in the fluid, for example, the heat exchange component can be used as an air radiator heat exchange assembly, and can also be used as a water heater heat exchange assembly.

Preferably, the box body has a circular cross section, and is provided with a plurality of heat exchange components, wherein one heat exchange component is arranged at the center of the circular cross section (the center pipe is arranged at the center of the circle) and the other heat exchange components are distributed around the center of the circular cross section.

Preferably, the tube bundle of the tube bank 1 is an elastic tube bundle.

The heat exchange coefficient can be further improved by arranging the tube bundle of the tube group 1 with an elastic tube bundle.

The number of the pipe groups 1 is multiple, and the plurality of pipe groups 1 are in a parallel structure.

The heat exchanger shown in fig. 6 has a circular cross-sectional housing in which the plurality of heat exchange members are disposed. Preferably, the number of the heat exchange components is three, the center of the central tube of each heat exchange component is located at the midpoint of an inscribed regular triangle of the circular cross section, the connecting lines of the centers of the central tubes form the regular triangle, one heat exchange component is arranged at the upper part of each central tube, two heat exchange components are arranged at the lower part of each central tube, and the connecting lines formed by the left side tube, the right side tube and the centers of the central tubes of the heat exchange components are of a parallel structure. Through such setting, can make and to fully reach vibrations and heat transfer purpose in can making the heat exchanger, improve the heat transfer effect.

Learn through numerical simulation and experiment, heat transfer part's size and circular cross-section's diameter have very big influence to the heat transfer effect, heat transfer part oversize can lead to adjacent interval too little, the space that the centre formed is too big, middle heat transfer effect is not good, the heat transfer is inhomogeneous, and on the same way, heat transfer part size undersize can lead to adjacent interval too big, leads to whole heat transfer effect not good. Therefore, the invention obtains the optimal size relation through a large amount of numerical simulation and experimental research.

The distance between the centers of the left side pipe and the right side pipe is L1, the side length of the inscribed regular triangle is L2, the radius of the axis of the innermost annular pipe in the annular pipes is R1, and the radius of the axis of the outermost annular pipe is R2, so that the following requirements are met:

10*(L1/L2)＝d*(10*R1/R2)-e*(10*R1/R2)²-f; wherein d, e, f are parameters,

44.102＜d＜44.110，3.715＜e＜3.782，127.385＜f＜127.395；

more preferably, d is 44.107, e is 3.718, f is 127.39;

of these, 720 < L2 < 1130mm is preferred. Preferably 0.58 < R1/R2 < 0.62.

Further preferably 0.30 < L1/L2 < 0.4.

Through the layout of the three heat exchange component structure optimization, the whole heat exchange effect can reach the best heat exchange effect.

Preferably, the pipe diameters of the left side pipe and the right side pipe are smaller than the pipe diameter of the middle pipe. The pipe diameter of the middle pipe is preferably 1.4-1.5 times of the pipe diameter of the left side pipe and the right side pipe. Through the pipe diameter setting of left side pipe, right side pipe and intermediate pipe, can guarantee that the fluid carries out the phase transition and keeps the same or close transmission speed at left side pipe, right side pipe and intermediate pipe to guarantee the homogeneity of conducting heat.

Preferably, the connection position of the coil pipe at the left channel box is lower than the connection position of the middle channel box and the coil pipe. This ensures that steam can rapidly enter the intermediate header. Similarly, the connecting position of the coil pipe at the right channel box is lower than the connecting position of the middle channel box and the coil pipe

Although the present invention has been described with reference to the preferred embodiments, it is not limited thereto. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A four-fluid pressure difference memory-regulated heat exchanger comprises a shell, a heat exchange part, a shell side inlet connecting pipe and a shell side outlet connecting pipe; the heat exchange component is arranged in the shell and fixedly connected to the front tube plate and the rear tube plate; the shell pass inlet connecting pipe and the shell pass outlet connecting pipe are both arranged on the shell; the shell pass fluid enters from a shell pass inlet connecting pipe, exchanges heat through the heat exchange part and exits from a shell pass outlet connecting pipe;

2. A shell and tube heat exchanger as claimed in claim 1, wherein in the fourth step, when the first and third fluids exchange heat and the second fluid does not exchange heat, if the left tube pressure or the right tube pressure or the average pressure of the left and right tubes in the previous period is P1 and the left tube pressure or the right tube pressure or the average pressure of the left and right tubes in the next period is P2, if the difference between P2 and P1 is lower than the threshold, the output test result is to control the first and third valves to be closed and the second valve to be opened, so that the first and third fluids stop exchanging heat and the second fluid exchanges heat; when the heat exchange of the first fluid and the third fluid is stopped and the second fluid exchanges heat, if the central pipe pressure of the previous time period is P1 and the central pipe pressure of the adjacent subsequent time period is P2, if the difference value between P2 and P1 is lower than a threshold value, the detection result is output, the first valve and the third valve are controlled to be opened, the second valve is controlled to be closed, the first fluid and the third fluid exchange heat, and the second fluid stops exchanging heat.

3. A shell and tube heat exchanger according to claim 1, characterized in that the first and second nozzles are located on the upper side of the central tube.

4. A shell-and-tube heat exchanger is characterized by comprising a plurality of circular arc-shaped annular tubes, wherein the end parts of the adjacent annular tubes are communicated, so that the annular tubes form a series structure.