CN104566939B - A kind of electric water-boiling device - Google Patents

Abstract

The invention discloses an electric water boiler, which includes a heating water tank, a boiling water tank, a warm boiling water tank and a connection box. Connection, the boiling water electric valve is installed on the boiling water discharge pipe, the heating water tank and the warm boiling water tank are connected through the warm water discharge pipe, and the warm water electric valve is installed on the warm water discharge pipe; an anti-boiling orifice plate is installed under the liquid surface of the heating water tank to heat the top space of the water tank It is connected with the top space of the warm water tank through a balance pipe, and the top space of the warm water tank is connected with the top space of the warm water tank through a balance hole; a heat exchanger is installed in the warm water tank, and the middle part of the heat exchanger is installed with a partition, a middle The partition and the lower partition, the heat exchanger are provided with a bypass pipe, and a bypass electric valve is provided on the bypass pipe; a breathing pipe is installed on the upper side wall of the warm water tank, and a breathing valve is installed on the breathing pipe; the control panel is installed on the connection box.

Description

an electric water heater

technical field

The invention relates to the technology of a drinking water boiler, in particular to an electric water boiler. The water boiler has remarkable energy-saving effect, is convenient to use and is beneficial to health.

Background technique

Drinking boiled water is a requirement for hygienic drinking water. The drinking water boiler that adopts electric heating has been widely used in public places such as schools, stations, hotels and company office buildings. Existing electric water boilers generally use a storage-type heating method, that is, when the user takes part of the boiled water, raw water is replenished and injected into the boiled water tank. However, this method will produce mixed water (commonly known as "yin and yang water"), and the temperature of the water will drop, so it needs to be heated again; then the water that has been heated before will participate in reheating, that is, water that has been heated repeatedly (commonly known as "thousand boiling water"). In addition, the general water boiler controls the liquid level, so that the boiled water enters the raw water when the liquid level is low. Although this will reduce the chance of mixing the boiled water and the raw water, it needs to wait for the raw water to be heated after the boiled water is used up, that is, The water intake time is not continuous, which affects the use and wastes energy. There are also electric water boilers that use the density of water at different temperatures and adopt layer-by-layer heating methods to try to solve the problem of discontinuous water intake time. However, this layered heating method does not have strict separation between boiling water and raw water. Therefore, the mixed water phenomenon will also occur during use. In terms of energy saving, some electric water boilers (such as existing patent CN 2473521Y) utilize the principle of heat exchange and cooling of boiling water and raw water to obtain energy saving effect, but there is also the problem of mixed water in it to varying degrees. Repeated heating of tap water will produce nitrite, and the nitrosamine produced by the action of nitrite and gastric acid in the body is a carcinogen. Therefore, in order to obtain boiled water for healthy drinking, an ideal electric water boiler can neither heat the boiled water repeatedly nor allow the boiled water to mix with raw water. On the other hand, people hope to obtain warm boiled water for direct drinking at any time, but it takes time to wait for cooling from boiled water to drinkable warm boiled water. .

Contents of the invention

Aiming at the deficiencies of the prior art, the technical problem to be solved by the present invention is to provide an electric water boiler, which can ensure that the raw water is heated only once, and the boiled water and the raw water are not mixed at all, and can be continuously supplied The boiled water and/or warm boiled water is beneficial to health, and has the characteristics of simple structure, convenient use, safety and reliability, remarkable energy-saving effect, and contributes to sanitation of drinking water and the like.

The technical solution of the present invention to solve the technical problem is: design an electric water boiler, including a heating water tank, a boiling water tank, a warm boiling water tank and a connection box, the heating water tank is located on the upper part of the electric water boiler, and the boiling water tank and the warm boiling water tank are located in the electric water boiler. The lower part of the water boiler is characterized in that there is a connecting box between the heating water tank, the boiling water tank and the warm boiling water tank; The warm water discharge pipe is connected, the warm water electric valve is installed on the warm water discharge pipe, the boiling water discharge pipe, the boiling water electric valve, the warm water discharge pipe and the warm water electric valve are all located inside the connection box; The top space of the water tank is connected with the top space of the warm water tank through a balance pipe, and the top space of the boiled water tank is connected with the top space of the warm water tank through a balance hole; a heat exchanger is installed in the warm water tank, and the middle part of the heat exchanger is installed The partition, middle partition and lower partition, the heat exchanger is equipped with a bypass pipe, and the bypass electric valve is installed on the bypass pipe; a breathing pipe is installed on the upper side wall of the warm water tank, and a breathing valve is installed on the breathing pipe; the control panel is installed On the connection box, and with the electric valve for boiling water, electric valve for warm water, electric heater, water level sensor for heating water tank, water temperature sensor for heating water tank, anti-dry heating temperature sensor, electric valve for water inlet, water level sensor for boiling water tank, water temperature sensor for boiling water tank, The water level sensor of the warm water tank, the water temperature sensor of the warm water tank, the raw water electric valve and the bypass electric valve are electrically connected.

Compared with the prior art, the electric water boiler of the present invention can ensure that the raw water is heated only once, and the boiled water and the raw water are not mixed at all. It is a healthy water boiler and can continuously supply healthy drinking water and/or warm boiled water , and has the characteristics of simple structure, convenient use, safety and reliability, remarkable energy-saving effect, and helpful for drinking water sanitation.

Description of drawings

Fig. 1 is a schematic diagram of the appearance and structure of an embodiment of the electric water boiler of the present invention.

Fig. 2 is a schematic diagram of the overall structure of an embodiment of the electric water boiler of the present invention.

detailed description

The electric water boiler of the present invention will be further described below in conjunction with the embodiments and accompanying drawings. The specific embodiments are only used to specifically illustrate the electric water boiler of the present invention, and do not constitute a limitation to the protection scope of the claims of the present application.

The electric water boiler designed by the present invention (see Fig. 1 and Fig. 2) comprises heating water tank 1, boiling water tank 2, warm boiling water tank 3 and connection box 4, is characterized in that heating water tank 1 is positioned at the top of electric water boiler, boiling water tank 2 It is located side by side with the warm water tank 3 at the lower part of the electric water boiler, and is characterized in that the connection box 4 is located in the middle of the electric water boiler; the heating water tank 1 and the boiling water tank 2 are connected through the boiling water discharge pipe 42 and the boiling water electric valve 43, and the heating water tank 1 and the warm water tank The boiling water tank 3 is connected with the warm water electric valve 45 through the warm water discharge pipe 44, and the boiling water discharge pipe 42, the boiling water electric valve 43, the warm water discharge pipe 44, and the warm water electric valve 45 are all located in the inside of the connection box 4;

An anti-boiling orifice 14 is installed under the liquid surface of the heating water tank 1, the head space of the heating water tank 1 is connected with the head space of the warm water tank 3 through a balance pipe 16, and the head space of the water tank 2 is connected with the head space of the warm water tank 3 through The balance hole 22 is connected;

A heat exchanger 31 is installed in the warm water tank 3, and an upper partition 32, a middle partition 33 and a lower partition 34 are respectively installed in the middle of the heat exchanger 31, and the heat exchanger 31 is provided with a bypass pipe 55 and a bypass electric valve 53 ; The upper side wall of the warm water tank 3 is equipped with a breathing pipe 77 and a breathing valve 78;

The control panel 41 is installed on the connection box 4, and is connected with the boiling water electric valve 43, the warm water electric valve 45, the electric heater 11, the heating water tank water level sensor 13, the heating water tank water temperature sensor 12, the anti-dry heating temperature sensor 17, the water inlet electric valve 54. Boiling water tank water level sensor 21, boiling water tank water temperature sensor 25, warm boiling water tank water level sensor 35, warm boiling water tank water temperature sensor 36, raw water electric valve 52 and bypass electric valve 53 are all electrically connected.

The working principle and process of the electric water boiler designed by the present invention (see Fig. 1 and Fig. 2) are: after connecting the power supply and the water supply pipeline, manually open the main water inlet valve 50, manually close the boiled water drain valve 63 and the warm boiled water drain valve 73 The initial states of the boiling water electric valve 43, the warm water electric valve 45, the raw water electric valve 52 and the water inlet electric valve 54 are closed, while the bypass electric valve 53 is open. After pressing the start button on the control panel 41, the following operations are automatically completed: the water inlet electric valve 54 is automatically opened, and the raw water coming out of the water inlet main valve 50 passes through the filter 51, and then passes through the bypass electric valve 53 and After the water inlet electric valve 54 enters the heating water tank 1, when the water level sensor 13 of the heating water tank detects that the water level reaches the high liquid level, the water inlet electric valve 54 is closed, and the electric heater 11 is opened to heat the raw water in the heating water tank 1. After the water temperature sensor 12 of the heating water tank detects that the water is boiled (as the temperature reaches 100° C.), the electric heater 11 stops heating, the electric valve 43 for boiling water and the electric valve 45 for warm water are opened, and the boiling water enters the boiling water tank 2 through the water discharge pipe 42 for boiling water. The water pipe 44 enters the warm water tank 3. When the water in the heating water tank 1 is exhausted, the electric valve for boiling water 43 and the electric valve for warm water 45 are closed; open, the other is closed; the opening of the raw water electric valve 52 is determined by the temperature obtained by the water temperature sensor 36 in the warm water tank 3, if the temperature is lower than the warm water outlet set temperature (such as 40 ℃), the raw water The electric valve 52 is closed, and the bypass electric valve 53 is opened at the same time. If the temperature is higher than the warm water outlet temperature (such as 40°C), the raw water electric valve 52 is opened, and the bypass electric valve 53 is closed at the same time. The warm boiled water tank 3 is empty, when the boiled water enters the warm boiled water tank 3 from the heated water tank 1 through the warm water discharge pipe 44, and the temperature is higher than the set temperature of the warm water outlet (such as 40°C), the raw water electric valve 52 is opened to bypass The electric valve 53 is closed, so that the heat exchanger 31 in the warm water tank 3 can realize the energy-saving effect of heat exchange. The condition that water inlet electric valve 54 is opened is: electric heater 11 stops, and boiling water electric valve 43 and warm water electric valve 45 are all closed, and heating water tank water level sensor 13 detects no liquid level, promptly heating water tank 1 is anhydrous. By comprehensively controlling the opening and closing of the water inlet electric valve 54, the boiling water electric valve 43 and the warm water electric valve 45, and the opening and closing of the electric heater 11, it is ensured that the raw water is only heated once and that the raw water and the boiling water are not mixed. The specific control process is: when the heating water tank 1 satisfies the water inlet condition, the water inlet electric valve 54 is opened, and when the liquid level detected by the heating water tank water level sensor 13 reaches the set liquid level (such as the high liquid level), the water inlet electric valve 54 is closed, the electric heater 11 starts, and starts heating. When the temperature detected by the heating water tank water temperature sensor 12 reaches the set temperature (such as 100° C.), the electric heater 11 stops heating, and now the boiling water is ready; then, if The liquid level detected by the boiling water tank water level sensor 21 is lower than the set liquid level (such as the high liquid level), then the boiling water electric valve 43 is opened, and the boiling water enters the boiling water tank 2 through the boiling water discharge pipe 42, and the boiling water electric valve reaches the set liquid level. 43 closes, and equally, if the liquid level that warm water tank water level sensor 35 detects is lower than setting liquid level (as high liquid level), then warm water electric valve 45 is opened, and boiled water enters warm water tank 3 by warm water discharge pipe 44, reaches When the liquid level is set, the warm water electric valve 45 is closed; in the process of discharging water from the heating water tank 1 to the boiling water tank 2 and the warm boiling water tank 3, when the water level sensor 13 of the heating water tank does not detect the liquid level, it indicates that the boiling water has been discharged, and the boiling water electric valve Both the valve 43 and the warm water electric valve 45 are closed, the water inlet condition is satisfied at this moment, the water inlet electric valve 54 is opened, the heating water tank 1 starts to enter water, and then enters the next cycle, and the heating water tank 1 has only one water intake and one heating for each cycle , but there can be several times of water release, that is, according to the liquid level in the boiling water tank 2 and the warm boiling water tank 3, the boiling water heated by the heating water tank 1 is put into the boiling water tank 2 and the warm boiling water tank 3 until the heating water tank 1 is completely discharged. until boiling water. Prevent dry burning by the function of the anti-dry heating temperature sensor 17, that is, as long as the anti-dry heating temperature sensor signal shows that the temperature is super high, the electric heater 11 is automatically cut off and cannot be opened, and the control panel shows a dry burning failure, waiting for maintenance; The water in the pipe of the heater 31 is heated, and when the electric water inlet valve 54 is in the closed state, the water heated volume expands and the pressure increases, and the excessive pressure is released from the safety valve 75; the control panel 41 provides heating The water temperature and liquid level indicator in water tank 1, boiling water tank 2 and warm boiling water tank 3, and provide the operating state of electric heater 11 and electric water boiler failure alarm; These have all guaranteed the safe operation of electric water boiler.

In order to be applicable to different demands of boiling water and warm boiling water, a further feature of the water boiler of the present invention is that the volumes of the heating water tank 1, the boiling water tank 2 and the warm boiling water tank 3 can be the same or different. It can also be adjusted according to needs when using.

A further feature of the water boiler of the present invention is that 2-4 taps can be provided on the boiling water tank 2 and the warm boiling water tank 3 of the water boiler as required. Embodiment 3 is designed to set 2 each.

Compared with the prior art, the electric water boiler design of the present invention connects the heating water tank 1 and the boiling water tank 2 with the boiling water discharge pipe 42, and controls the communication between the heating water tank 1 and the boiling water tank 2 with the boiling water electric valve 43; Discharge pipe 44 to connect heating water tank 1 and warm boiling water tank 3, control the connection between heating water tank 1 and warm boiling water tank 3 with warm water electric valve 45; The opening and closing of 54 and the opening and stopping of the electric heater 11 can ensure that the raw water is no longer mixed with the raw water after being heated once in the heating water tank 1, and is no longer heated, which avoids the need for existing electric boiling water. The mixed water (yin and yang water) situation of the device; there is no heating device in the boiling water tank 2 and the warm boiling water tank 3, that is, the water boiled once from the heating water tank 1 will not be heated again, so repeated heating of the water is prevented ( Thousands of boiling water); by controlling the opening and closing of the raw water electric valve 52 and the bypass electric valve 53, the water outlet temperature of the warm water outlet faucet 71 of the warm water tank 3 can be adjusted, and the upper partition plate 32 of the heat exchanger 31 1. The middle partition 33 and the lower partition 34 divide the warm boiled water tank 3 into four regions from top to bottom, and the boiling water of the heating water tank 1 flows into the four regions from top to bottom of the warm boiled water tank 3 through the drain pipe 44, Under the heat exchange effect of the heat exchanger 31, the boiled water gradually becomes warm boiled water from top to bottom in the warm boiled water tank 3. However, the raw water flowing into the heat exchanger 31 from the raw water inlet pipe 56 absorbs the The heat of the boiling water gradually increases from bottom to top, and flows out from the raw water outlet pipe 57, and then enters the heating water tank 1 through the water inlet pipe 58. The result of the heat exchange of the heat exchanger 31 is that the boiling water releases heat, and the temperature drops to become Warm boiling water, raw water absorbs heat, the temperature rises to become hot water, raw water recycles the heat released by boiling water, and saves energy; the anti-boiling orifice 14 is installed under the liquid level of the heating water tank 1 to play a fast and uniform water temperature and prevent water from boiling. The violent boiling of the water splashes to the water surface space to generate a large amount of steam. The steam produced can be introduced into the warm water tank 3 through the balance pipe 16 between the heating water tank 1 and the warm water tank 3, and the steam is condensed into water in the warm water tank 3. Recycling of heat and water; the heating water tank 1 is not provided with an air outlet for direct exhaust to the outside world, through the balance pipe 16, the balance hole 22 between the boiling water tank 2 and the warm boiling water tank 3, the upper space of the warm boiling water tank 3 and the outside world The connected breather valve 78 can balance the increased pressure of the heated water tank 1 due to steam and liquid volume expansion during the heating process by the headspace of the warm boiled water tank 3 and boiled water tank 2. If the set pressure is exceeded, the breather valve will 78 exhaust outwards and carry out pressure relief, same, because the hot water outlet faucet 61 of boiling water tank 2 and the warm boiling water outlet faucet 71 of warm water tank 3 make the air pressure in the tank drop in the water discharge process, then by breather valve 78 to warm water tank 3 Internal air intake to balance the pressure, therefore, by adjusting the pressure of the breathing valve 78 connected to the warm water tank 3 to the external environment, the electric water boiler can be used in plateau places with low air pressure; While obtaining healthy drinking water and warm water conveniently and quickly, The utility model can realize high efficiency and energy saving, and has wide application.

What is not mentioned in the present invention is applicable to the prior art.

Provide the specific embodiment of water boiler of the present invention below.

Example 1

The embodiment of the electric water boiler designed by the present invention (see FIGS. 1 and 2 ) includes a heating water tank 1 , a boiling water tank 2 , a warm boiling water tank 3 and a connection section 4 . The three water tanks are all made of food-grade stainless steel, and the water volumes of the three water tanks are basically the same. The feature is that the heating water tank 1 is located on the upper part of the electric water boiler, and the boiling water tank 2 and warm water tank 3 are located on the bottom of the electric water boiler. The lower part, and between the heating water tank 1 and the boiling water tank 2 and the warm boiling water tank 3 is a connection box 4; Connect with the warm water tank 3 by the warm water discharge pipe 44, the warm water electric valve 45 is installed on the warm water discharge pipe 44, the boiling water discharge pipe 42, the boiling water electric valve 43, the warm water discharge pipe 44, and the warm water electric valve 45 are positioned at the inside of the connection box 4; An anti-boiling orifice 14 is installed under the liquid surface of the water tank 1, the head space of the heating water tank 1 and the head space of the warm water tank 3 are connected through a balance pipe 16, and the head space of the boiling water tank 2 and the head space of the warm water tank 3 pass through a balance hole 22 connected; a heat exchanger 31 is installed in the warm water tank 3, and an upper partition 32, a middle partition 33 and a lower partition 34 are installed in the middle of the heat exchanger 31, and the heat exchanger 31 is provided with a bypass pipe 55, and the bypass pipe The bypass electric valve 53 is set on the 55; the upper side wall of the warm water tank 3 is equipped with a breathing tube 77, and the breathing valve 78 is installed on the breathing tube 77; Valve 45, electric heater 11, heating water tank water level sensor 13, heating water tank water temperature sensor 12, anti-dry heating temperature sensor 17, water inlet electric valve 54, boiling water tank water level sensor 21, boiling water tank water temperature sensor 25, warm boiling water tank water level sensor 35. The water temperature sensor 36 of the warm water tank, the raw water electric valve 52, and the bypass electric valve 53 are electrically connected; the electric heater 11 is installed at the bottom of the heating water tank 1, and the water level sensor 13 of the heating water tank with seven measuring points is installed on the side wall. Heating water tank water temperature sensor 12 and anti-dry temperature sensor 17; water inlet pipe 58 is installed on the top of heating water tank 1, water inlet electric valve 54 is installed on the water inlet pipe 58, and the side wall of boiling water tank 2 is installed with twelve measuring points for boiling water tank water level Sensor 21 and boiling water tank water temperature sensor 25, the bottom of boiling water tank 2 installs boiling water outlet faucet 61, the bottom of boiling water tank 2 installs boiling water tank drainpipe 62 and boiling water drain valve 63; The side wall of warm boiling water tank 3 installs twelve measuring points Warm boiled water tank water level sensor 35 and warm boiled water tank water temperature sensor 36; The drainage of breathing valve 78 enters overflow drainpipe 79; The drain pipe 72 and the warm water drain valve 73, the raw water inlet pipe 56 are three-way connected to the pressure relief pipe 76 and the safety valve 75, and the raw water inlet pipe 56 is sequentially installed with the main water inlet valve 50, the filter 51 and the raw water electric valve 52 , between filter 51 and raw water electric valve 52 three-way connection bypass pipe 55, raw water outlet pipe 57, bypass pipe 55 and water inlet pipe 58 three-way connection; The overflow drainpipe 79 of the warm water drain valve 73 of water tank 3, breathing valve 78, safety valve 75 are all connected with drainage main pipe 74. Connect; the heat insulation layer between the outer insulation layer 18 of the heating water tank and the bottom insulation layer 19 of the heating water tank, the outer insulation layer 26 of the boiling water tank 2 and the warm boiling water tank 3 and the top insulation layer 37, the boiling water tank 2 and the warm boiling water tank 3 24 are polyurethane foam insulation materials, the outer surface 15 of the heating water tank of the outer insulation layer 18 of the heating water tank, the outer insulation surface 23 of the outer insulation layer 26 of the boiling water tank 2 and the warm boiling water tank 3 and the outer wall 46 of the connection box 4 are all stainless steel Protective plate; the heat-resistant insulation layer 47 of the boiling water discharge pipe 42 in the connection box 4, the boiling water electric valve 43, the warm water discharge pipe 44, the warm water electric valve 45 and the balance pipe 16, and the raw water outlet pipe 57 and the water inlet electric valve 54 and the energy-saving insulation layer 59 of water inlet pipe 58 are all rubber-plastic sponge insulation materials.

Example 2

Design an electric water boiler, the volume ratio of the heating water tank 1, boiling water tank 2, and warm boiling water tank 3 is 1:1:2. The warm boiled water tank 3 of this design can become bigger, can adapt to the needs of a large amount of fast warm boiled water. Others are the same as embodiment 1.

Example 3

Design an electric water boiler with two faucets on both the boiling water tank 2 and the warm boiling water tank 3 . Others are the same as embodiment 1.

Claims (3)

1. A control method for an electric water boiler, comprising a heating water tank, a boiling water tank, a warm boiling water tank and a connection box, the heating water tank is positioned at the top of the electric water boiler, and the boiling water tank and the warm boiling water tank are positioned at the bottom of the electric water boiler, characterized in that There is a connection box between the heating water tank, the boiling water tank and the warm boiling water tank; the heating water tank and the boiling water tank are connected through the boiling water discharge pipe, and the boiling water electric valve is installed on the boiling water discharge pipe, and the heating water tank and the warm boiling water tank are connected through the warm water discharge pipe, and the warm water discharge pipe The warm water electric valve is installed on the top, the boiling water discharge pipe, the boiling water electric valve, the warm water discharge pipe and the warm water electric valve are all located inside the connection box; an anti-boiling orifice plate is installed under the liquid level of the heating water tank, and the top space of the heating water tank is connected with the warm water tank. The top space of the water tank is connected by a balance pipe, and the top space of the boiling water tank is connected with the top space of the warm water tank through a balance hole; a heat exchanger is installed in the warm water tank, and the upper partition, the middle partition and the lower partition are installed in the middle of the heat exchanger. The separator and the heat exchanger are provided with a bypass pipe, and a bypass electric valve is provided on the bypass pipe; a breathing pipe is installed on the upper side wall of the warm water tank, and a breathing valve is installed on the breathing pipe; the control panel is installed on the connection box, and is connected with the boiling water Electric valve, warm water electric valve, electric heater, heating water tank water level sensor, heating water tank water temperature sensor, anti-dry temperature sensor, water inlet electric valve, boiling water tank water level sensor, boiling water tank water temperature sensor, warm boiling water tank water level sensor, warm opening The water temperature sensor of the water tank, the raw water electric valve and the bypass electric valve are electrically connected; The specific control process is: when the heating water tank meets the water inlet conditions, the water inlet electric valve is opened, when the liquid level detected by the water level sensor of the heating water tank reaches the set level, the water inlet electric valve is closed, the electric heater is started, and heating is started , when the temperature detected by the water temperature sensor of the heating water tank reaches the set temperature, the electric heater stops heating, and the boiling water is ready at this time; The electric valve opens, and the boiling water enters the boiling water tank through the boiling water discharge pipe. When the set liquid level is reached, the boiling water electric valve closes. Similarly, if the liquid level detected by the water level sensor of the warm boiling water tank is lower than the set liquid level, the warm water electric valve opens. Boiling water enters the warm water tank through the warm water discharge pipe, and the warm water electric valve closes when the set liquid level is reached; during the process of discharging water from the heating water tank to the boiling water tank and the warm boiling water tank, when the water level sensor of the heating water tank cannot detect the liquid level, it indicates that the water is boiling It has been discharged, the electric valve for boiling water and the electric valve for warm water are both closed. At this moment, the water inlet condition is satisfied, the electric water inlet valve is opened, the heating water tank starts to fill in water, and then enters the next cycle. The heating water tank has only one water intake and one Heating, but water can be released several times, that is, according to the liquid level situation in the boiling water tank and the warm boiling water tank, the boiling water heated by the heating water tank is put into the boiling water tank and the warm boiling water tank until the boiling water in the heating water tank is put. 2. The control method of the electric water boiler according to claim 1, characterized in that 2-4 faucets are provided on the boiling water tank and the warm boiling water tank of the water boiler as required. 3. The control method of the electric water boiler according to claim 1, characterized in that the volumes of the heating water tank, the boiling water tank and the warm boiling water tank are the same or different.