CN112648734B

CN112648734B - Electric water heater with intelligent layout

Info

Publication number: CN112648734B
Application number: CN202011499462.4A
Authority: CN
Inventors: 王逸隆
Original assignee: Qingdao University of Science and Technology
Current assignee: Shandong Weixinze Photoelectric Technology Co.,Ltd.
Priority date: 2019-03-12
Filing date: 2019-03-12
Publication date: 2022-07-05
Anticipated expiration: 2039-03-12
Also published as: CN111380214A; CN112594923A; CN112629026B; CN112648734A; CN112594923B; CN112629026A; CN111380214B

Abstract

The invention provides an intelligent descaling electric water heater, wherein a water tank is of a circular section, a plurality of electric heating devices are arranged, one electric heating device is arranged in the center of the water tank and becomes a central electric heating device, and the other electric heating devices are distributed around the center of the water tank and become peripheral electric heating devices. The invention designs a layout of an electric heating device with a novel structure in a water tank, which can further improve the heating efficiency.

Description

Electric water heater with intelligent layout

Technical Field

The invention relates to a water heater, in particular to an intermittent vibration descaling electric water heater.

Background

The water heater is an essential household appliance in the family life at present. At present, an electric water heater is generally adopted and is used for heating. In applicant's prior application, a new coil type electric heating coil, such as CN106123306A, was developed and studied to vibrate the elastic tube bundle due to the expansion of the fluid therein caused by heating, thereby achieving heating and descaling effects.

However, in applications where it is found that continuous heating of the electric heater results in fluid stability of the internal electric heating means, i.e. the fluid is not flowing or is flowing very little, or the flow is stable, the vibration performance of the coil is greatly reduced, and thus the efficiency of the coil for descaling and heating is affected. There is therefore a need for improvements to the electrically heated resilient coil described above.

Disclosure of Invention

The invention provides an electric heating water heater with a novel structure aiming at the defects of water heaters in the prior art. The water heater can realize the periodic frequent vibration of the coil pipe, and improves the heating efficiency, thereby realizing good descaling and heating effects.

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

an electric water heater capable of intelligently descaling comprises a controller, an electric heating device and a water tank, wherein the electric heating device is arranged in the water tank, the water tank comprises a water inlet pipe and a water outlet pipe, the electric heating device comprises a first pipe box, a second pipe box and a coil pipe, the coil pipe is communicated with the first pipe box and the second pipe box to form closed circulation of heating fluid, and the electric heating device is arranged in the first pipe box; filling phase-change fluid in the first channel; the number of the coil pipes is one or more, each coil pipe comprises a plurality of arc-shaped pipe bundles, the central lines of the arc-shaped pipe bundles are arcs taking the first pipe box as a concentric circle, and the end parts of the adjacent pipe bundles are communicated, so that the end parts of the pipe bundles form free ends of the pipe bundles; the heating fluid is phase-change fluid, the electric heating device is in data connection with a controller, and the controller controls the heating power of the electric heating device to periodically change along with the change of time.

Preferably, the heating power P of the electric heating device varies in a regular manner during one cycle time T as follows:

0-T/2, P ═ n, where n is a constant number in watts;

T/2-T，P＝0。

preferably, T is 50-80 minutes, wherein 4000W < n < 5000W.

An electric water heater capable of intelligently descaling comprises an electric heating device and a water tank, wherein the electric heating device is arranged in the water tank, the water tank comprises a water inlet pipe and a water outlet pipe, the electric heating device comprises a first pipe box, a second pipe box and a coil pipe, the coil pipe is communicated with the first pipe box and the second pipe box to form closed circulation of heating fluid, and an electric heater is arranged in the first pipe box; filling phase-change fluid in the first channel; the number of the coil pipes is one or more, each coil pipe comprises a plurality of arc-shaped pipe bundles, the central lines of the arc-shaped pipe bundles are arcs taking the first pipe box as a concentric circle, and the end parts of the adjacent pipe bundles are communicated, so that the end parts of the pipe bundles form free ends of the pipe bundles; the electric heating device is characterized in that a plurality of electric heaters are arranged, each electric heater is independently controlled, and the starting number of the electric heaters changes periodically along with the change of time; and n electric heaters are arranged, one electric heater is started at intervals of T/2n in a period T until the heaters are all started at the time T/2, and then one electric heater is closed at intervals of T/2n until the heaters are all closed at the time T.

Preferably, the heating power of each electric heater is the same.

Preferably, the period is 50 to 300 minutes; the average heating power of the electric heating device is 2000-4000W.

An electric water heater for intelligent layout comprises an electric heating device and a water tank, wherein the electric heating device is arranged in the water tank, the water tank comprises a water inlet pipe and a water outlet pipe, the electric heating device comprises a first pipe box, a second pipe box and a coil pipe, the coil pipe is communicated with the first pipe box and the second pipe box to form closed circulation of heating fluid, and an electric heater is arranged in the first pipe box; filling phase-change fluid in the first channel; the number of the coil pipes is one or more, each coil pipe comprises a plurality of arc-shaped pipe bundles, the central lines of the arc-shaped pipe bundles are arcs taking the first pipe box as a concentric circle, and the end parts of the adjacent pipe bundles are communicated, so that the end parts of the pipe bundles form free ends of the pipe bundles; the water tank is characterized in that the water tank is of a circular section, the number of the electric heating devices is multiple, one electric heating device is arranged in the center of the water tank and becomes a central electric heating device, and the other electric heating devices are distributed around the center of the water tank and become peripheral electric heating devices.

Preferably, the heating power of the single peripheral electric heating means is smaller than the heating power of the central electric heating means.

An electric water heater distributed intelligently at intervals comprises an electric heating device and a water tank, wherein the electric heating device is arranged in the water tank, the water tank comprises a water inlet pipe and a water outlet pipe, the electric heating device comprises a first pipe box, a second pipe box and a coil pipe, the coil pipe is communicated with the first pipe box and the second pipe box to form closed circulation of heating fluid, and an electric heater is arranged in the first pipe box; filling phase-change fluid in the first channel; the number of the coil pipes is one or more, each coil pipe comprises a plurality of arc-shaped pipe bundles, the central lines of the arc-shaped pipe bundles are arcs taking the first pipe box as a concentric circle, and the end parts of the adjacent pipe bundles are communicated, so that the end parts of the pipe bundles form free ends of the pipe bundles; the coil pipe is characterized in that the first pipe box and the second pipe box are arranged along the height direction, the coil pipes are arranged along the height direction of the first pipe box, and the inner diameter of each coil pipe is continuously reduced from top to bottom.

Preferably, the inner diameter of the coil pipe is gradually decreased from the top to the bottom of the first header.

The invention has the following advantages:

1. the electric heating device provided by the invention intermittently heats in a period, and can realize periodic frequent vibration of the elastic coil, so that good descaling and heating effects are realized.

2. The invention increases the heating power of the coil pipe periodically and continuously and reduces the heating power, so that the heated fluid can generate the volume which is continuously in a changing state after being heated, and the free end of the coil pipe is induced to generate vibration, thereby strengthening heat transfer.

3. The invention designs a layout of an electric heating device with a novel structure in a water tank, which can further improve the heating efficiency.

4. The invention optimizes the optimal relationship of the parameters of the coil pipe through a large amount of experiments and numerical simulation, thereby realizing the optimal heating efficiency.

Description of the drawings:

fig. 1 is a top view of an electric heating apparatus of the present invention.

Fig. 2 is a front view of the electric heating apparatus.

Fig. 3 is a coordinate diagram of intermittent heating of the electric heating device.

Fig. 4 is a graph illustrating the coordinates of the periodic increase and decrease in heating power of the electric heating device.

Fig. 5 is a schematic coordinate diagram of another embodiment of periodically increasing and decreasing heating power of an electric heating device.

Fig. 6 is a coordinate diagram of the linear change of the heating power of the electric heating device.

Fig. 7 is a layout schematic diagram of an electric heating device arranged in a circular water tank.

Fig. 8 is a schematic view of the coil configuration.

Fig. 9 is a schematic view of the structure of the water tank.

In the figure: 1. coil pipe, 2, first pipe box, 3, free end, 4, free end, 5, water inlet pipe, 6, water outlet pipe, 7, free end, 8, second pipe box, 9, connecting point, 10, electric heating device, 11, water tank, 12 pipe bundle, 13 electric heater

Detailed Description

An electric water heater comprises an electric heating device 10 and a water tank 11, wherein the electric heating device 10 is arranged in the water tank 11, and the water tank 11 comprises a water inlet pipe 5 and a water outlet pipe 6.

Fig. 1 shows a top view of an electric heating apparatus 10, as shown in fig. 1, the electric heating apparatus 10 includes a first pipe box 2, a second pipe box 8 and a coil 1, the coil 1 is communicated with the first pipe box 2 and the second pipe box 8, a fluid circulates in the first pipe box 2, the second pipe box 8 and the coil 1 in a closed manner, an electric heater 13 is disposed in the electric heating apparatus 10, and the electric heater 13 is used for heating the fluid in the electric heating apparatus 10 and then heating water in a water tank by the heated fluid.

As shown in fig. 1-2, an electric heater 13 is disposed in the first header tank 2; the first channel box 2 is filled with phase-change fluid; the number of the coil pipes 1 is one or more, each coil pipe 1 comprises a plurality of circular arc-shaped pipe bundles 12, the central lines of the circular arc-shaped pipe bundles 12 are circular arcs taking the first pipe box 2 as a concentric circle, the end parts of the adjacent pipe bundles 12 are communicated, and fluid forms serial flow between the first pipe box 2 and the second pipe box 8, so that the end parts of the pipe bundles form free ends 3 and 4 of the pipe bundles; the fluid is phase-change fluid, vapor-liquid phase-change liquid, the electric heating device is in data connection with the controller, and the controller controls the heating power of the electric heating device to periodically change along with the change of time.

Preferably, the first and

second headers

2 and 8 are provided along a height direction.

It has been found in research and practice that continuous power-stable heating of the electric heater results in a stable fluid formation of the internal electric heating means, i.e. the fluid is not flowing or has little fluidity, or the flow is stable, resulting in a greatly reduced vibrational performance of the coil 1, thereby affecting the efficiency of descaling and heating of the coil 1. There is therefore a need for an improvement to the electrical heating coil described above as follows.

Preferably, the heating power is a batch type heating method.

As shown in fig. 3, the heating power P of the electric heater varies regularly during one period time T as follows:

in a half period of 0-T/2, P ═ n, where n is a constant number in watts (W), i.e., the heating power remains constant;

and P is 0 in the half period of T/2-T. I.e. the electric heater does not heat.

T is 50-80 minutes, wherein 4000W < n < 5000W.

Through the heating 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 heating efficiency and the descaling operation can be further realized.

Preferably, the electric heater 13 is provided in a plurality, each electric heater is independently controlled, and the number of the activated electric heaters is periodically changed along with the change of time.

Preferably, the number of the electric heaters is n, one electric heater is started at intervals of T/2n in one period T until the heaters are all started at the time of T/2n, and then one electric heater is stopped at intervals of T/2n until the heaters are all stopped at the time of T.

Preferably, the heating power of each electric heater is the same. The relationship diagram is shown in fig. 4.

Preferably, the electric heater is arranged in a plurality of sections along the height direction, each section is independently controlled, and the electric heater is sequentially started from the lower end to all the sections along the height direction in a half period T/2 along with the change of time, and then is sequentially closed from the upper end to all the sections in the following half period T/2 along with the change of time.

That is, assuming that the electric heater is n segments, in a period T, every T/2n time, starting one segment from the lower end until all segments are started at T/2n time, and then every T/2n time, starting from the upper end, closing one segment until all segments are closed at T time.

Preferably, the heating power is the same for each section. The relationship diagram is shown in fig. 4.

The electric heater is started from the lower part upwards gradually, so that the fluid at the lower part is fully heated, a good natural convection is formed, the flow of the fluid is further promoted, and the elastic vibration effect is increased. Through the change of the heating power with 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 heating efficiency and the descaling operation can be further realized.

Preferably, the number of the electric heaters 13 is multiple, each electric heater 13 has different power, one or more electric heaters can be combined to form different heating powers, in the last half cycle, according to a time sequence, the single electric heater is started firstly, the single electric heater is independently started according to a sequence that the heating power is sequentially increased, then the two electric heaters are started, the two electric heaters are independently started according to a sequence that the heating power is sequentially increased, then the number of the started electric heating devices is gradually increased, and if the number is n, the n electric heaters are independently started according to a sequence that the heating power is sequentially increased; and ensuring that the heating power of the electric heating devices is increased in sequence until all the electric heaters are started finally. In the next half period, the single electric heater is not started independently according to the sequence that the heating power is increased sequentially, then the two electric heaters are not started, the two electric heaters are not started independently according to the sequence that the heating power is increased sequentially, then the number that the electric heating device is not started is increased gradually, and if the number is n, the n electric heaters are not started independently according to the sequence that the heating power is increased sequentially; and (3) until all the electric heaters are not started, ensuring that the heating power of the electric heaters is reduced in sequence.

For example, the number of the electric heating devices is three, namely a first electric heating device D1, a second electric heating device D2 and a third electric heating device D3, and the heating powers are P1, P2 and P3 respectively, wherein P1 < P2 < P3, and PI + P2 > P3; the sum of the first electric heating device and the second electric heating device is larger than that of the third electric heating device, the first, the second, the third, the first plus the second, the first plus the third, the second plus the third, then the first, the second and the third are started in sequence according to the time sequence, and the sequence of not starting in the next half period is the first, the second, the third, the first plus the second, the first plus the third, the second plus the third, then the first, the second and the third.

The heating power is gradually increased and decreased through the electric heater, the flowing of the fluid is further promoted, and the elastic vibration effect is increased. Through the change of the heating power with 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 heating efficiency and the descaling operation can be further realized.

Preferably, the heating power of the electric heating device is linearly increased in the first half period, and the heating power of the electric heating device is linearly decreased in the second half period, see fig. 6.

The linear variation of the heating power is achieved by a variation of the input current or voltage.

By arranging the plurality of electric heaters, the starting of the electric heaters with gradually increased quantity is realized, and the linear change is realized.

Preferably, the period is 50 to 300 minutes, preferably 50 to 80 minutes; the average heating power of the electric heating device is 2000-4000W.

Preferably, the connection position 9 of the coil pipe at the first header is lower than the connection position of the second header and the coil pipe. This ensures that steam can rapidly enter the second header upwards.

Preferably, return pipes are provided at the bottom of the first and second channel boxes to ensure that the fluid condensed in the second channel box can enter the first pipeline.

Preferably, the first and second headers are arranged in a height direction, the coil pipe is provided in plural numbers in the height direction of the first header, and a pipe diameter of the coil pipe is gradually reduced from top to bottom.

Preferably, the pipe diameter of the coil pipe is gradually decreased and gradually increased along the direction from the top to the bottom of the first pipe box.

The pipe diameter range through the coil pipe increases, can guarantee that more steam passes through upper portion and gets into the second box, guarantees that the distribution of steam is even in all coil pipes, further reinforces the heat transfer effect 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 plurality of coils are arranged along the height direction of the first tube box, and the distance between the adjacent coils is increased from the top to the bottom.

Preferably, the distance between the coils increases along the height direction of the first header.

The interval range through the coil pipe increases, can guarantee that more steam passes through upper portion and gets into the second box, guarantees that the distribution of steam is even in all coil pipes, further reinforces the heat transfer effect 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, as shown in fig. 7, the water tank is a water tank having a circular cross section, and a plurality of electric heating devices are provided in the water tank.

Preferably, as shown in fig. 7, a plurality of electric heaters are disposed in the water tank, one of which is disposed at the center of the water tank to become a central electric heater, and the others are distributed around the center of the water tank to become peripheral electric heaters. Through such structural design, can be so that the interior fluid of water tank fully reaches the vibration purpose, improve the heat transfer effect.

Preferably, the heating power of the single peripheral electric heating means is smaller than the heating power of the central electric heating means. Through the design, the center reaches higher vibration frequency to form a central vibration source, so that the periphery is influenced, and better heat transfer enhancement and descaling effects are achieved.

Preferably, on the same horizontal heat exchange section, the fluid needs to achieve uniform vibration, and uneven heat exchange distribution is avoided. It is therefore necessary to distribute the amount of heating power among the different electric heating devices reasonably. Experiments show that the heating power ratio of the central electric heating device to the peripheral tube bundle electric heating device is related to two key factors, wherein one of the two key factors is the distance between the peripheral electric heating device and the center of the water tank (namely the distance between the circle center of the peripheral electric heating device and the circle center of the central electric heating device) and the diameter of the water tank. Therefore, the invention optimizes the optimal proportional distribution of the pulsating flow according to a large number of numerical simulations and experiments.

Preferably, the radius of the inner wall of the water tank is B, the center of the central electric heating device is arranged at the center of the circular cross section of the water tank, the distance from the center of the peripheral electric heating device to the center of the circular cross section of the water tank is S, the centers of adjacent peripheral electric heating devices are respectively connected with the center of the circular cross section, the included angle formed by the two connecting lines is a, the heating power of the peripheral electric heating device is W2, and the heating power of a single central electric heating device is W1, so that the following requirements are met:

W1/W2 ═ a-B ═ Ln (B/S); ln is a logarithmic function;

a and b are coefficients, wherein 1.855 < a < 1.865 and 0.600 < b < 0.610;

1.25＜B/S＜2.1；

1.4＜W1/W2＜1.8。

wherein 35 DEG < A < 80 deg.

Preferably, the number of the four-side distribution is 4-5.

Preferably, R is 1600-2400 mm, preferably 2000 mm; l is 1200-2000 mm, preferably 1700 mm; the diameter of the heat exchange tube is 12-20 mm, preferably 16 mm; the outermost diameter of the pulsating coil is 300-560 mm, preferably 400 mm. The diameter of the riser is 100-116 mm, preferably 108 mm, the height of the riser is 1.8-2.2 m, preferably 2 m, and the spacing between adjacent pulse tubes is 65-100 mm. Preferably around 80 mm.

The total heating power is preferably 4000-10000W, more preferably 5500W.

More preferably, a is 0.18606 and b is 0.6041.

Preferably, the box body has a circular cross section, and is provided with a plurality of electric heating devices, wherein one electric heating device is arranged at the center of the circular cross section and the other electric heating devices are distributed around the center of the circular cross section.

The coil 1 is one or more groups, each group of coil 1 includes a plurality of circular arc-shaped tube bundles 12, the central lines of the circular arc-shaped tube bundles 12 are circular arcs of concentric circles, and the ends of the adjacent tube bundles 12 are communicated, so that the ends of the coil 1 form tube bundle free ends 3, 4, such as the free ends 3, 4 in fig. 2.

Preferably, the heating fluid is a vapor-liquid phase-change fluid.

Preferably, the first header 2, the second header 8, and the coil 1 are all of a circular tube structure.

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

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

Preferably, the concentric circles are circles centered on the center of the first header 2. I.e. the tube bundle 12 of the coil 1 is arranged around the centre line of the first tube box 2.

As shown in fig. 4, the tube bundle 12 is not a complete circle, but rather leaves a mouth, thereby forming the free end of the tube bundle. The angle of the arc of the mouth part is 65-85 degrees, namely the sum of included angles b and c in figure 5 is 65-85 degrees.

Preferably, the ends of the tube bundle on the same side are aligned in the same plane, with the extension of the ends (or the plane in which the ends lie) passing through the median line of the first tube box 2.

Further preferably, the electric heater 13 is an electric heating rod.

Preferably, the first end of the inner tube bundle of the coil 1 is connected to the first tube box 2, the second end is connected to one end of the adjacent outer tube bundle, one end of the outermost tube bundle of the coil 1 is connected to the second tube box 8, and the ends of the adjacent tube bundles are connected to form a serial structure.

The plane in which the first end is located forms an angle c of 40-50 degrees with the plane in which the centre lines of the first and

second headers

2, 8 are located.

The plane of the second end forms an angle b of 25-35 degrees with the plane of the centre lines of the first and

second headers

2, 8.

Through the design of the optimized included angle, the vibration of the free end is optimized, and therefore the heating efficiency is optimized.

As shown in fig. 8, there are 4 tube bundles of coil 1, with tube bundles A, B, C, D in communication. Of course, the number is not limited to four, and a plurality of the connecting structures are provided as required, and the specific connecting structure is the same as that in fig. 8.

The number of the coil pipes 1 is multiple, and the plurality of coil pipes 1 are respectively and independently connected with the first pipe box 2 and the second pipe box 8, that is, the plurality of coil pipes 1 are in a parallel structure.

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. An electric water heater for intelligent layout comprises an electric heating device and a water tank, wherein the electric heating device is arranged in the water tank, the water tank comprises a water inlet pipe and a water outlet pipe, the electric heating device comprises a first pipe box, a second pipe box and a coil pipe, the coil pipe is communicated with the first pipe box and the second pipe box to form closed circulation of heating fluid, and an electric heater is arranged in the first pipe box; filling phase-change fluid in the first channel; the number of the coil pipes is one or more, each coil pipe comprises a plurality of arc-shaped pipe bundles, the central lines of the arc-shaped pipe bundles are arcs taking the first pipe box as a concentric circle, and the end parts of the adjacent pipe bundles are communicated, so that the end parts of the pipe bundles form free ends of the pipe bundles; the water tank is characterized in that the water tank is of a circular section, the number of the electric heating devices is multiple, one electric heating device is arranged in the center of the water tank and becomes a central electric heating device, and the other electric heating devices are distributed around the center of the water tank and become peripheral electric heating devices;

the heating power of the single peripheral electric heating device is smaller than that of the central electric heating device.