CN113028862B

CN113028862B - Shell-and-tube heat exchanger started by hotel energy-saving cooperative communication

Info

Publication number: CN113028862B
Application number: CN202110456752.9A
Authority: CN
Inventors: 赵炜; 罗凯宬
Original assignee: Qingdao Vocational And Technical College Of Hotel Management
Current assignee: Qingdao Vocational And Technical College Of Hotel Management
Priority date: 2019-11-15
Filing date: 2019-11-15
Publication date: 2023-01-24
Anticipated expiration: 2039-11-15
Also published as: CN113028862A; CN113028888A; CN113028888B; CN111928700B; CN111928700A

Abstract

The invention provides an energy-saving shell-and-tube heat exchanger for hotels, which comprises a shell, wherein tube plates are respectively arranged at two ends of the shell, a heat exchange component is arranged in the shell, the heat exchange component comprises a central tube, a left tube, a right tube and a tube group, and a first outlet and a second outlet are arranged at two opposite sides of the central tube; the position of the right tube group is the position of the left tube group after rotating 180 degrees along the axis of the central tube; the heat exchange components are arranged into 2 groups, each group of heat exchange components is multiple, each heat exchange component is independently controlled, and the starting number of the first group of heat exchange components and the starting number of the second group of heat exchange components are periodically changed along with the change of time. The invention can lead the fluid to be frequently evaporated, expanded and contracted in the elastic tube bundle by the heat exchange with the time variability, thereby continuously driving the vibration of the elastic tube bundle and further realizing the heat exchange efficiency and the descaling operation.

Description

Shell-and-tube heat exchanger started by hotel energy-saving cooperative communication

Technical Field

The invention relates to a shell-and-tube heat exchanger, in particular to an energy-saving shell-and-tube heat exchanger for hotels. Used for homes, hotels, clubs, etc.

Background

In hotels, each equipment needs a high-temperature heat source, and a mode of taking hot water or steam as the heat source is usually adopted. With the social development and the improvement of living standard, the heat source supply system is widely used in places such as houses, hotels, offices, bath centers, and convention centers. Most of heat source supply systems in the prior art adopt oil and gas boilers to heat hot water, steam to heat hot water and the like, heating cost is high, and waste gases such as sulfur dioxide, carbon monoxide, carbon dioxide and the like are easily generated by heating with gas and oil to cause environmental pollution. Meanwhile, heat energy in waste water and waste gas generated in the industry cannot be effectively utilized, energy waste is caused, and optimal combination of heat sources is not facilitated.

Shell-and-tube heat exchangers are widely used in various fields, and due to the worldwide energy crisis, the demand of heat exchangers in industrial production is increasing and the quality requirements of heat exchangers are also increasing in order to reduce energy consumption. 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 in the 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, a physical cleaning mode is adopted, and 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.

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 this regard, we have developed a new shell-and-tube heat exchanger capable of generating periodic vibration, and have already filed patent applications.

However, in practice, the vibration of the tube bundle is adjusted through the fixed periodic change, in the prior application, research is conducted on the heat exchange of a single heat exchange device, but the problem of uneven heat exchange of the whole heat exchange device exists, for example, the heat exchange power may have different heights along with the time. .

Disclosure of Invention

The invention provides an electric heating shell-and-tube heat exchanger with a novel structure, aiming at the defects of the shell-and-tube heat exchanger in the prior art. The shell-and-tube heat exchanger can realize the periodic frequent vibration of the heat exchange tube, and improves the heat exchange efficiency, thereby realizing good descaling and heat exchange effects.

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

a shell-and-tube heat exchanger comprises a shell, tube plates are respectively arranged at two ends of the shell, a heat exchange component is arranged in the shell and comprises a central tube, a left tube, a right tube and a tube group, the tube group comprises 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 group form closed circulation of heating fluid, an electric heater is arranged in the central tube, and the position of the right tube group is the position of the left tube group rotated by 180 degrees along the axis of the central tube; the heat exchange components are divided into two groups, and the two groups of heat exchange components exchange heat alternately to realize periodic frequent vibration of the elastic coil.

Preferably, the tube groups are multiple, each tube group comprises a plurality of circular arc-shaped annular tubes, the ends of the adjacent annular tubes are communicated, the plurality of annular tubes form a serial structure, and the ends 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 and second outlets are disposed on opposite sides of the central tube.

Preferably, the annular tubes of the left tube group are distributed by taking the axis of the left tube as the center of a circle, and the annular tubes of the right tube group are distributed by taking the axis of the right tube as the center of a circle.

The invention has the following advantages:

1. according to the invention, two groups of heat exchange parts are arranged to alternately exchange heat, so that the heat exchange heating efficiency is improved, the integral heat exchange heat is ensured to be uniform, and the good descaling and heat exchange effects are realized.

2. The invention provides a vibrating tube bundle shell-and-tube heat exchanger with a novel structure, which increases the vibration range of a tube bundle by arranging more tube groups in a limited space, thereby strengthening heat transfer and enhancing descaling.

3. The heat exchange efficiency can be further improved by arranging the pipe diameters and the intervals of the pipe groups in the length direction.

4. The invention optimizes the optimal relation of the parameters of the shell-and-tube heat exchanger through a large amount of experiments and numerical simulation, thereby realizing the optimal heat exchange efficiency.

5. The invention designs a triangular layout diagram of a multi-heat-exchange-component with a novel structure, optimizes the structural parameters of the layout, and can further improve the heat exchange efficiency through the layout.

Description of the drawings:

fig. 1 is a schematic view of a housing structure.

Fig. 2 is a top view of a heat exchange member of the present invention.

Fig. 3 is a front view of the heat exchange member of the present invention.

Fig. 4 is a front view of another embodiment of a heat exchange member of the present invention.

Fig. 5 is a dimensional structure schematic diagram of the heat exchange component of the invention.

Fig. 6 is a schematic layout of the heat exchange component of the present invention in a circular cross-section heat exchanger.

In the figure: 1. the device comprises a tube group, a left tube group 11, a

right tube group

12, 21, a left tube 22, a right tube 3, a free end 4, a free end 5, a free end 6, a free end 7, a ring tube 8, a central tube 9, an electric heater, a first tube opening 10, a second tube opening 13, a left return tube 14, a right return tube 15, a front tube plate 16, a support 17, a support 18, a rear tube plate 19, a

shell

20, 21, a shell inlet connecting tube 22, a shell outlet connecting tube and a heat exchange component 23.

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 part 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 23 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 heating fluid circulation, the central tube 8 is filled with a phase-change fluid, an electric heater 9 is arranged in the central tube 8, each tube group 1 comprises a plurality of circular arc-shaped annular tubes 7, the ends of the adjacent annular tubes 7 are communicated, so that the plurality of annular tubes 7 form a series structure, and the ends of the annular tubes 7 form annular tube free ends 3-6; 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 opposite sides of the central tube 8.

The end portions of both 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.

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. Preferably both ends of the central tube

The fluid is heated and evaporated in the central tube 8 and flows to the left and

right headers

21 and 22 along the annular tube bundle, the fluid is heated and then undergoes volume expansion to form steam, and the volume of the steam is far greater than that of water, so that the formed steam can flow in the coil in a rapid impact manner. 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.

According to the invention, the prior art is improved, and the condensation 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 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.

Preferably, the annular tubes of the left tube group are distributed by taking the axis of the left tube as the center of a circle, and the annular tubes of the right tube group are distributed by taking the axis of the right tube 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 position of the right tube group (including the right tube) is a position of the left tube group (including the left tube) rotated by 180 degrees (angle) along the axis of the center tube. Through such setting, can make the annular pipe distribution of heat transfer reasonable more even, improve the heat transfer effect.

Preferably, the

headers

8, 21, 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 obtained by adopting the structural design.

Preferably, the tube groups on the same side (left or right) are provided in plural along the length of the center tube 8, and the distance between adjacent tube groups on the same side (left or right) becomes smaller in 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 obtained by adopting the structural design.

Research and practice find that the heat exchange of the heat exchange component with continuous power stability can cause the fluid of the internal heat exchange component to form stability, namely the fluid does not flow or has little fluidity, or the flow is stable, so that the vibration performance of the coil 1 is greatly weakened, and the descaling of the coil 1 and the heat exchange efficiency are affected. Therefore, the following improvements are required for the above heat exchange member.

In the prior application, the heat exchange of a single heat exchange part is researched, but the problem of uneven overall heat exchange exists, for example, the heat exchange power is different along with the time.

Preferably, the heat exchange power adopts a batch heat exchange mode.

The heat exchange components are divided into two groups, and the two groups of heat exchange components exchange heat alternately to realize periodic frequent vibration of the elastic coil.

In a period T, the heat exchange power P of each heat exchange component in the first group changes according to the following rule:

p = n in a half period of 0-T/2, wherein n is a constant value and is in watt (W), namely the heat exchange power is kept constant;

p =0 in the half period of T/2-T. I.e. the heat exchange part does not exchange heat.

The heat exchange power P of the second group of single heat exchange components is changed according to the following rule:

p =0 in the half period of 0-T/2. I.e. the heat exchange part does not exchange heat.

In a half period of T/2-T, P = n, wherein n is a constant value and is in watt (W), namely the heat exchange power is kept constant;

preferably, T is 50 to 80 minutes, wherein 1000W < -n < -5000W.

Through the heat exchange with the time variability, the fluid can be frequently evaporated, expanded and contracted in the elastic tube bundle, so that the vibration of the elastic tube bundle is continuously driven, and the heat exchange efficiency and the descaling operation can be further realized.

The heat exchange components are divided into two groups, so that the heat exchange power and the heat exchange efficiency of the heat exchange components can be improved as a whole.

Preferably, the number of heat exchange members in each group is the same.

Further preferably, the heat exchange components are divided into n groups, each group does not exchange heat alternately, and in one period T, n-1 groups exchange heat and 1 group does not exchange heat.

Namely, in a cycle time T, the change rule of the heat exchange power P of each heat exchange component of 1 group is as follows:

The change rule of the heat exchange power P of the other n-1 groups of heat exchange components is as follows:

P = n in a half period of T/2-T, wherein n is a constant value and is in watt (W), namely the heat exchange power is kept constant;

preferably, the heat exchange power of a single heat exchange component is 1000W-n-5000W

Preferably, the number of heat exchange parts in each group is the same.

Preferably, the heat exchange parts are arranged into 2 groups, each group of heat exchange parts is multiple, each heat exchange part is independently controlled, and the starting number of the first group of heat exchange parts and the starting number of the second group of heat exchange parts are periodically changed along with the change of time.

Preferably, when the operation is started, the first group of heat exchange components are all closed, the second group of heat exchange components are all started, and each group of heat exchange components is n, so that in a period T, one heat exchange component is started in the first group of heat exchange components at intervals of T/2n until the heat exchange device is all started at the T/2 time, and then one heat exchange component is closed at intervals of T/2n until the heat exchange device is all closed at the T time. In the second group of heat exchange components, one heat exchange component is closed every T/2n until the heat exchange device is completely closed at the T/2n time, and then one heat exchange component is opened every T/2n until the heat exchange device is completely opened at the T time.

Preferably, each heat exchange component has the same heat exchange power.

Through the heat exchange with the time variability, the fluid can be frequently evaporated, expanded and contracted in the elastic tube bundle, so that the elastic tube bundle is continuously driven to vibrate, and the heat exchange efficiency and the descaling operation can be further realized.

The total heat exchange power can be ensured to be kept the same through the opening and closing of the two groups of heat exchange components.

Preferably, the number of the heat exchange components is 3, the heat exchange components are respectively a first heat exchange component, a second heat exchange component and a third heat exchange component, and in a period of time T, the change rule of the heat exchange power P of the 3 heat exchange components is as follows:

in the first one third period of 0-T/3, the heat exchange power P = n of the first heat exchange component and the second heat exchange component, wherein n is a constant value and the unit is watt (W), namely the heat exchange power of the first heat exchange component and the heat exchange power of the second heat exchange component are kept constant; p =0 of the third heat exchange means;

in the middle third period of T/3-2T/3, the heat exchange power P = n of the first heat exchange component and the third heat exchange component, wherein n is a constant value and the unit is watt (W), namely the heat exchange power of the first heat exchange component and the heat exchange power of the third heat exchange component are kept constant; p =0 of the second heat exchange means;

in the last third period of 2T/3-T, the heat exchange power P = n of the second heat exchange component and the third heat exchange component, wherein n is a constant numerical value and the unit is watt (W), namely the heat exchange power of the second heat exchange component and the heat exchange power of the third heat exchange component are kept constant; p =0 for the first heat exchange member.

Preferably, the period is 50 to 300 minutes, preferably 50 to 80 minutes.

In tests it was found that the tube diameter, distance of the left and

right side tubes

21, 22 and the central tube 8 and the tube diameter of the ring tubes can have an effect on the heat exchange efficiency and 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 tube diameter of the left tube 21, the tube diameter of the central tube 8, and the radius of 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*(R/L) ² -b (R/L) + c; wherein a, b, c are parameters, wherein 4.834<a<4.835，1.390<b<1.391，0.5585<c<0.5590; preferably, a =4.8344, b =1.3906, and c =0.5587.

Preferably, 34-yarn-R-yarn-woven fabric is 61mm;114 were constructed of L-woven fabric 191mm; 69-straw R1-straw 121mm, 119-straw R2-straw 201mm.

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

Preferably, 0.57-woven fabric R1/R2<0.61;0.3 sOm R/L <0.32.

Preferably, 0.583-woven fabric R1/R2<0.60;0.304 and R/L <0.316.

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

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 optimized included angle, the vibration of the free end is optimal, and therefore the heat exchange efficiency is optimal.

The heating power of the electric heater is preferably 1000 to 2000W, and more preferably 1500W.

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

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

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

Further preferably, the electric heater is an electric heating rod.

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 exchanging elements are disposed. Preferably, three heat exchange components are arranged in the shell, the center of a center pipe of each heat exchange component is positioned in an inscribed regular triangle with a circular cross section, the connecting lines of the centers of the center pipes form a regular triangle, one heat exchange component is arranged at the upper part, two heat exchange components are arranged at the lower part, and the connecting lines formed by the centers of the left side pipe, the right side pipe and the center pipe of each heat exchange component 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 relationship through a great deal 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,

34.71<d<34.72,2.9315<e<2.9320,99.338<f<99.345；

further preferably, d =34.716, e =2.9319, f =99.342;

among them, 720-L2-1130 mm are preferable. Preferably 0.58< R1/R2<0.62.

More 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.

When three heat exchange parts are arranged, three groups of heat exchange parts can be preferably arranged, and each group of heat exchange parts carries out intermittent heat exchange;

it is preferable that two sets are provided, two sets are provided at the lower portion, and one heat exchange part at the upper portion is provided at one set, to perform intermittent heat exchange.

It has been found in research and practice that a sustained, stable heat source results in fluid-forming stability of the internal heat exchange components, i.e., no or little fluid flow, or a steady flow rate, resulting in a significant reduction in the vibrational performance of the tube bank 1, thereby affecting the efficiency of heat exchange and descaling of the tube bank 1. Therefore, the heat pipe described above needs to be improved as follows.

In the inventor's prior application, a periodic heat exchange mode is provided, and the vibration of the heat exchange 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 device can realize frequent vibration, and good descaling and heat exchange effects are realized.

The invention provides a novel electric heating heat exchanger capable of intelligently controlling vibration, aiming at the defects in the technology studied in advance. The heat exchanger can improve the heat exchange efficiency, thereby realizing good descaling and heat exchange effects.

Preferably, the heat exchange is carried out in the manner described above in the descaling process.

1. Pressure-based autonomous vibration adjustment

Preferably, a pressure detection element is arranged in the heat exchange component and used for detecting the pressure in the heat exchange component, the pressure detection element is in data connection with the controller, and the controller controls the electric heater to heat or not according to the detected pressure.

Preferably, the controller controls the electric heater to stop heating if the pressure detected by the pressure detecting element is higher than a certain value, and controls the electric heater to heat if the pressure detected by the pressure detecting element is lower than a certain value.

The pressure detected by the pressure detecting element can basically reach saturation when the certain pressure is met, and the volume of the internal fluid is not changed greatly basically. So that the fluid undergoes volume reduction to thereby realize vibration. When the pressure 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.

Preferably, the pressure detecting elements are arranged in the central tube 8 and/or the left side tube 21 and/or the right side tube 22.

Preferably, the pressure detecting elements are disposed within the center tube 8 and the left and

right side tubes

21 and 22. The average of the pressures of the three channel boxes can be selected as regulating data at this time.

Preferably, the pressure detecting element is provided at the free end. Through setting up at the free end, can perceive the pressure variation of free end to realize better control and regulation.

2. Self-regulating vibration based on temperature

Preferably, a temperature detection element is arranged in the heat exchange component and used for detecting the temperature in the heat exchange component, the temperature detection element is in data connection with the controller, and the controller controls whether the electric heater heats or not according to the detected temperature.

Preferably, the controller controls the electric heater to stop heating if the temperature detected by the temperature detecting element is higher than a certain value, and controls the electric heater to heat if the temperature detected by the temperature detecting element is lower than a certain value.

The pressure detected by the temperature detecting element can basically saturate the evaporation of the internal fluid and the volume of the internal fluid is not changed greatly under the condition of meeting a certain temperature, and in this case, the internal fluid is relatively stable, the vibration of the tube bundle is reduced, and therefore adjustment is needed to vibrate the tube bundle so as to stop heating. So that the fluid undergoes a volume reduction to thereby realize vibration. When the temperature 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.

Preferably, the temperature detecting element is provided at an upper end disposed in the center tube 8 and/or the left side tube 21 and/or the right side tube 22.

Preferably, the temperature detecting elements are provided at the upper ends of the center tube 8 and the left and

right side tubes

21 and 22.

Preferably, the temperature detection element is provided at the free end. Through setting up at the free end, can perceive the temperature variation of free end to realize better control and regulation.

3. Vibration based on liquid level autonomous regulation

Preferably, a liquid level detecting element is arranged in the central tube 8 and used for detecting the liquid level of the fluid in the lower tube box, the liquid level detecting element is in data connection with a controller, and the controller controls whether the electric heater heats or not according to the detected liquid level of the fluid.

Preferably, the controller controls the electric heater to stop heating if the liquid level detected by the liquid level detecting element is lower than a certain value. The liquid level detected by the liquid level detection element is higher than a certain value, and the controller controls the electric heater to heat.

In the case where the liquid level detected by the liquid level detecting element satisfies a certain liquid level (for example, the lowest limit), the evaporation of the fluid inside is substantially saturated, and the volume of the fluid inside is not substantially changed. So that the fluid undergoes volume reduction to thereby realize vibration. When the liquid level rises 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 evaporate and expand again, so that the electric heater needs to be started for heating.

4. Autonomous vibration adjustment based on speed

Preferably, a speed detection element is arranged in the free end of the tube bundle and used for detecting the flow speed of the fluid in the free end of the tube bundle, the speed detection element is in data connection with the controller, and the controller controls whether the electric heater heats or not according to the detected speed of the fluid.

Preferably, the controller controls the electric heater to stop heating if the speed detected by the speed detecting element is higher than a certain value. The liquid level detected by the speed detection element is lower than a certain value, and the controller controls the electric heater to heat.

The speed detected by the speed detecting element can be adjusted to vibrate the tube bundle to stop heating, because the internal fluid is relatively stable and the tube bundle is deteriorated in vibration property in the case where the evaporation of the internal fluid is substantially saturated to form a stable flow and the speed of the internal fluid is not substantially changed when a certain speed (for example, the highest upper limit) is satisfied. So that the fluid undergoes a volume reduction to thereby realize vibration. When the speed drops 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 evaporate and expand again, so that the electric heater needs to be started for heating.

Preferably, the heat exchanger comprises a descaling process, and the descaling process is used for heat exchange in the manner described above.

The invention also comprises intelligent control, and the specific technical scheme is as follows:

control of outlet water temperature

The shell pass outlet is provided with a temperature sensor, the temperature sensor is in data connection with the data acquisition controller, a preset temperature T1 of fluid at the shell pass outlet is set, and the T1 is stored in the data acquisition controller; the data acquisition controller acquires the temperature T2 detected by the temperature sensor; the data acquisition controller compares T2 with T1; and the data acquisition controller controls the heating power of the electric heater to heat according to the comparison result.

Preferably, if T2> T1, the data acquisition controller automatically controls to reduce the heating power, and if T2< T1, the data acquisition controller automatically controls to increase the heating power; if T2= T1, the data acquisition controller automatically controls the heating power to be kept unchanged.

Preferably, the magnitude of the heating power is controlled by controlling the magnitude of the voltage input to the electric heater.

Preferably, the plurality of temperature sensors are provided, and the controller controls the operation of the heater based on the temperature data measured by the plurality of temperature sensors.

Control of fluid flow

The shell side inlet pipe is provided with a valve, the valve is in data connection with the data acquisition controller, the preset temperature T1 of fluid at the shell side outlet is set, and the T1 is stored in the data acquisition controller; the data acquisition controller acquires the temperature T2 detected by the temperature sensor; the data acquisition controller compares T2 with T1; and the data acquisition controller controls the opening and closing and the opening of the valve according to the comparison result.

Preferably, if T2> T1, the data acquisition controller automatically controls the valve to increase the opening degree, and if T2< T1, the data acquisition controller automatically controls the valve to decrease the opening degree; and if T2= T1, the opening of the automatic control valve of the data acquisition controller is kept unchanged. By controlling the opening of the valve, the flow is increased when the temperature is high, and the flow is reduced when the temperature is low, so that the constancy of the outlet temperature is ensured.

Preferably, the temperature sensor is a plurality of temperature sensors, and the controller controls the operation of the heater according to temperature data measured by the plurality of temperature sensors.

(III) control of the shell pressure

A pressure sensor is arranged in the shell, the pressure sensor is in data connection with the data acquisition controller, a shell pass preset pressure P1 is set, and the P1 is stored in the data acquisition controller; the data acquisition controller acquires pressure P2 detected by the pressure sensor; the data acquisition controller compares P2 with P1; and the data acquisition controller controls the heating power of the electric heater to heat according to the comparison result. Through so setting up, can adjust heating power according to the pressure in the casing, avoid pressure too big to guarantee the safety of heat exchanger.

Preferably, the data collection controller automatically controls to reduce the heating power if P1< P2<0.9 × P1, and automatically controls to stop the heating power to heat if P2> = P1.

Preferably, the pressure sensor is a plurality of pressure sensors, and the controller controls the operation of the heater according to the pressure data measured by the plurality of pressure sensors.

The pressure sensor is arranged at the upper position of the shell.

Preferably, the pressure sensors are multiple, and the controller controls the operation of the heat exchanger according to the pressure data measured by the multiple pressure sensors.

Control of shell exhaust

A pressure sensor is arranged in the shell and is in data connection with a data acquisition controller, and an exhaust valve is arranged at the upper part of the shell side and is in data connection with the data acquisition controller; setting a shell pass preset pressure P1, and storing the P1 in a data acquisition controller; the data acquisition controller acquires pressure P2 detected by the pressure sensor; the data acquisition controller compares P2 with P1; and the data acquisition controller controls the opening and closing of the exhaust valve according to the comparison result. Through so setting up, can adjust discharge valve according to the pressure in the casing, avoid pressure too big to guarantee the safety of heat exchanger.

Preferably, if P2>0.98 × P1, the data acquisition controller automatically controls the exhaust valve to open until P2< =0.9 × P1, the data acquisition controller automatically controls the exhaust valve to close.

The pressure sensor is arranged at the upper position of the shell.

It should be noted that the heating power of the electric heater is the average power of the entire heating time.

Although the present invention has been described in connection with 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. An energy-saving shell-and-tube heat exchanger for hotels comprises a shell, wherein tube plates are arranged at two ends of the shell respectively, heat exchanging components are arranged in the shell and comprise a central tube, a left tube, a right tube and tube groups, 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 closed circulation of heating fluid, an electric heater is arranged in the central tube, and the position of the right tube group is the position of the left tube group rotated by 180 degrees along the axis of the central tube; the device comprises a plurality of pipe groups, wherein each pipe group comprises a plurality of circular arc-shaped annular pipes, the end parts of the adjacent annular pipes are communicated, so that the plurality of annular pipes form a serial structure, and the end parts of the annular pipes form free ends of the annular pipes; 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 two opposite sides of the central pipe; the heat exchange device is characterized in that the number of the heat exchange components is 2, each group of heat exchange components is multiple, each heat exchange component is independently controlled, the starting number of the first group of heat exchange components and the second group of heat exchange components is periodically changed along with the change of time, when the heat exchange device starts to operate, the first group of heat exchange components are completely closed, the second group of heat exchange components are completely started, and each group of heat exchange components is n, so that in a period T, one heat exchange component is started in the first group of heat exchange components at intervals of T/2n until the heat exchange device is completely started at intervals of T/2n, and then one heat exchange component is closed at intervals of T/2n until the heat exchange device is completely closed at intervals of T;

in the second group of heat exchange components, one heat exchange component is closed every T/2n until the heat exchange device is completely closed at T/2n, and then one heat exchange component is opened every T/2n until the heat exchange device is completely opened at T.

2. The heat exchanger of claim 1, wherein each heat exchange member has the same heat exchange power.