CN112303898B

CN112303898B - Water heater capable of changing heating component according to water level

Info

Publication number: CN112303898B
Application number: CN201910681952.7A
Authority: CN
Inventors: 沈保山; 刘治彩; 张爱云; 高永强; 麻晓飞; 陈燕慧; 吴芷红
Original assignee: Wuxi Institute of Technology
Current assignee: Shanghai Yijian Automotive Technology Co ltd
Priority date: 2019-07-26
Filing date: 2019-07-26
Publication date: 2022-01-28
Anticipated expiration: 2039-07-26
Also published as: CN112303898A

Abstract

The invention provides a water heater, which 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 hot water outlet, 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 heater is arranged in the first pipe box; the first liquid level sensing element and the second liquid level sensing element are in data connection with the controller, and the controller controls whether the first electric heater and the second electric heater are used for heating or not according to the detected liquid levels of the fluid in the first channel box and the second channel box. The water heater changes the heating part through the liquid level detected by the liquid level sensing element, so that the fluid flows towards different directions. And a new electric heater is started to alternately heat by detecting the liquid level change in the first channel and the second channel, so that the heating effect and the descaling effect are improved.

Description

Water heater capable of changing heating component according to water level

Technical Field

The invention relates to hot water generating equipment, in particular to an intermittent vibration descaling 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.

In a previous application (e.g., application No. 2019101874848) of the university of Qingdao technology, referring to FIG. 6, intermittent heating was used to vibrate the coil, but the intermittent heating resulted in a period of time during which heating was not possible, resulting in a reduction in heating power. Therefore, the invention is improved, adopts a more reasonable heating mode and improves the heating efficiency.

However, in the application, it is found that the continuous heating of the electric heater can cause the fluid of the internal electric heating device to form stability, that is, the fluid does not flow or flows little, or the flow is stable, so that the vibration performance of the coil is greatly weakened, thereby affecting the descaling of the coil and the heating efficiency.

However, in practice it has been found that adjusting the vibration of the tube bundle by a fixed periodic variation can result in hysteresis and excessively long or short periods. 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 heating effects can be realized.

Disclosure of Invention

Aiming at the defects in the technology researched in the prior art, the invention provides a novel electric heating water heater capable of intelligently controlling vibration. This water heater can improve heating efficiency to realize fine scale removal and heating effect.

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

a water heater 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 hot water outlet, 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 heater is arranged in the first pipe box; 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; a first electric heater and a second electric heater are respectively arranged in the first channel box and the second channel box; filling phase-change fluid in the first channel and/or the second channel; the liquid level detection device is characterized in that a first liquid level sensing element and a second liquid level sensor are respectively arranged in the first channel box and the second channel box and used for detecting the liquid levels of fluids in the first channel box and the second channel box, the first liquid level sensing element and the second liquid level sensing element are in data connection with a controller, and the controller controls whether the first electric heater and the second electric heater are used for heating or not according to the detected liquid levels of the fluids in the first channel box and the second channel box.

Preferably, when the first electric heater heats and the second electric heater does not heat, and the liquid level in the first channel detected by the first liquid level sensing element is lower than a certain value, the controller controls the first electric heater to stop heating and the second electric heater to heat; when the second electric heater heats and the first electric heater does not heat, and the liquid level in the second channel detected by the second liquid level sensing element is lower than a certain value, the controller controls the second electric heater to stop heating and the first electric heater to heat.

The invention has the following advantages:

1. the water heater of the invention can basically reach the saturation of the evaporation of the internal fluid and the little change of the volume of the internal fluid under the condition of meeting a certain liquid level (such as the lowest limit) through the liquid level detected by the liquid level sensing element, under the condition, the internal fluid is relatively stable, the vibration of the tube bundle is poor, and therefore, the adjustment is needed to change the heating component, so that the fluid flows towards different directions. And a new electric heater is started to alternately heat by detecting the liquid level change in the first channel and the second channel, so that the heating effect and the descaling effect are improved.

2. 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.

3. 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.

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 layout diagram of an electric heating device arranged in a circular water tank.

Fig. 4 is a schematic diagram of the coil arrangement.

Fig. 5 is a schematic view of the structure of the water tank.

Fig. 6 is a background art drawing.

Fig. 7 is a control flow diagram.

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

Detailed Description

A 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 hot water outlet 6.

Preferably, the water tank is of cylindrical configuration.

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,

electric heaters

131, 132 are 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, a first electric heater 131 and a second electric heater 132 are provided in the first and

second header tanks

2 and 8, respectively; the first channel box 2 and/or the second channel box 8 are 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 first electric heater 131 and the second electric heater 132 are in data connection with a controller, and the controller controls the first electric heater 131 and the second electric heater 132 to heat.

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.

In the inventor's prior application, a periodic heating manner is proposed, in which the

electric heaters

131 and 132 in the first and second tube boxes are continuously switched to heat by the periodic heating manner, so as to continuously promote the vibration of the coil, thereby improving the heating efficiency and the descaling effect. 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 heating effects can be realized.

Self-regulation vibration based on pressure

Preferably, a first pressure sensor and a second pressure sensor are respectively disposed in the first tube box 2 and the second tube box 8 for detecting pressures in the first tube box and the second tube box, the first pressure sensor and the second pressure sensor are in data connection with a controller, and the controller controls whether the first electric heater 131 and the second electric heater 132 heat or not according to the detected pressures in the first tube box and the second tube box.

Preferably, when the first electric heater heats and the second electric heater does not heat, and the pressure detected by the first pressure sensing element is higher than a certain value, the controller controls the first electric heater to stop heating and the second electric heater to heat; when the second electric heater heats and the first electric heater does not heat, the pressure detected by the second pressure sensing element is higher than a certain value, the controller controls the second electric heater to stop heating, and the first electric heater heats.

Through the pressure that the pressure perception element detected, can satisfy under certain pressure condition, the evaporation of the fluid of first channel inside or second channel has basically reached saturation, and the volume of inside fluid also basically does not change greatly, and under this kind of circumstances, inside fluid is relatively stable, and the tube bank vibration nature at this moment worsens, therefore needs adjust, changes the heating part, makes the fluid flow towards different directions. Therefore, the new electric heater is started to perform alternate heating by detecting the pressure change in the first channel box and the second channel box, and the heating effect and the descaling effect are increased.

Independently adjusting vibration based on temperature

Preferably, a first temperature sensor and a second temperature sensor are respectively disposed in the first tube box 2 and the second tube box 8 for detecting the temperature in the first tube box and the second tube box, the first temperature sensor and the second temperature sensor are in data connection with a controller, and the controller controls whether the first electric heater 131 and the second electric heater 132 heat or not according to the detected temperature in the first tube box and the second tube box.

Preferably, when the first electric heater heats and the second electric heater does not heat, and the temperature detected by the first temperature sensing element is higher than a certain value, the controller controls the first electric heater to stop heating and the second electric heater to heat; when the second electric heater heats and the first electric heater does not heat, the temperature detected by the second temperature sensing element is higher than a certain value, the controller controls the second electric heater to stop heating, and the first electric heater heats.

The temperature detected by the temperature sensing element can basically saturate the evaporation of the fluid in the first channel or the second channel and basically reduce the volume change of the internal fluid under the condition of meeting a certain temperature, and under the condition, the internal fluid is relatively stable, the vibration of the tube bundle is reduced, so that the adjustment is needed, the heating part is changed, and the fluid flows towards different directions. Therefore, the new electric heater is started to perform alternate heating by detecting the temperature change in the first channel box and the second channel box, and the heating effect and the descaling effect are increased.

Thirdly, automatically adjusting vibration based on liquid level

Preferably, a first liquid level sensing element and a second liquid level sensor are respectively arranged in the first channel box and the second channel box and used for detecting the liquid levels of the fluids in the first channel box and the second channel box, the first liquid level sensing element and the second liquid level sensing element are in data connection with a controller, and the controller controls whether the first electric heater 131 and the second electric heater 132 are heated or not according to the detected liquid levels of the fluids in the first channel box and the second channel box.

The liquid level detected by the liquid level sensing element can basically reach saturation in evaporation of the internal fluid and basically does not change much in volume of the internal fluid under the condition of meeting a certain liquid level (such as the lowest limit). And a new electric heater is started to alternately heat by detecting the liquid level change in the first channel and the second channel, so that the heating effect and the descaling effect are improved.

Fourthly, automatically adjusting vibration based on speed

Preferably, a speed sensing 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 sensing element is in data connection with the controller, and the controller controls whether the first electric heater and the second electric heater are used for heating or not according to the detected speed of the fluid.

Preferably, when the first electric heater heats and the second electric heater does not heat, if the speed detected by the speed sensing element is higher than a certain value, the controller controls the first electric heater to stop heating and the second electric heater to heat. When the second electric heater heats and the first electric heater does not heat, if the speed detected by the speed sensing element is higher than a certain value, the controller controls the second electric heater to stop heating and the first electric heater to heat.

The speed detected by the speed sensing element can basically reach saturation of the evaporation of the internal fluid under the condition of meeting a certain speed (such as the highest upper limit), so that stable flow is formed, and the speed of the internal fluid basically does not change greatly. And a new electric heater is started to alternately heat by detecting the speed change, so that the heating effect and the descaling effect are improved.

Preferably, the speed sensing element is disposed at the free end. Through setting up at the free end, can perceive the speed change of free end to realize better control and regulation.

Preferably, the pipe diameter of the first pipe box 2 is equal to that of the second pipe box 8. The pipe diameters of the first pipe box and the second pipe box 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 as the second pipe box.

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, the bottom parts of the first channel box and the second channel box are provided with return pipes, so that the fluid condensed in the first channel box and the second channel box can quickly flow.

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 first, two boxes, guarantees that the distribution of steam is even in all coil pipes, further reinforces the heat transfer effect 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.

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 first, two boxes, guarantees that the distribution of steam is even in all coil pipes, further strengthens heat transfer effect 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.

Preferably, as shown in fig. 3, the water tank is a water tank with a circular cross section, and a plurality of electric heating devices are arranged in the water tank.

Preferably, as shown in fig. 3, 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, b are coefficients, where 1.855< a <1.865,0.600< b < 0.610;

1.25< B/S <2.1；

1.4< W1/W2<1.8。

wherein 35 ° < a <80 °.

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-. 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.

Further preferably, a =0.18606 and b = 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 coils 1 are in one or more groups, each group of coils 1 comprises 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 coils 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 preferable included angle, the vibration of the free end is optimal, and therefore the heating efficiency is optimal.

As shown in fig. 5, 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. 5.

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. A water heater 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 hot water outlet, 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 heater is arranged in the first pipe box; 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; a first electric heater and a second electric heater are respectively arranged in the first channel box and the second channel box; filling phase-change fluid in the first channel and/or the second channel; the liquid level detection device is characterized in that a first liquid level sensing element and a second liquid level sensor are respectively arranged in the first channel box and the second channel box and used for detecting the liquid levels of fluids in the first channel box and the second channel box, the first liquid level sensing element and the second liquid level sensing element are in data connection with a controller, and the controller controls whether the first electric heater and the second electric heater are used for heating or not according to the detected liquid levels of the fluids in the first channel box and the second channel box.

2. The water heater according to claim 1, wherein when the first electric heater heats and the second electric heater does not heat, and the liquid level in the first pipe box detected by the first liquid level sensing element is lower than a certain value, the controller controls the first electric heater to stop heating and the second electric heater to heat; when the second electric heater heats and the first electric heater does not heat, and the liquid level in the second channel detected by the second liquid level sensing element is lower than a certain value, the controller controls the second electric heater to stop heating and the first electric heater to heat.