TWI388784B - Electric storage water heater - Google Patents

Description

Storage water heater

This invention relates to an electric water heater, and more particularly to an electric storage water heater.

At present, the more common electric water heaters can be roughly divided into two types: electric instantaneous water heaters and storage type electric water heaters. Among them, the instant electric water heater usually does not have the function of storing hot water, and the hot water temperature provided by the electric water heater is relatively easy to decrease as the water flow rate increases, and the water storage type electric water heater can pass through the water storage tank (water- Storage tank) to store hot water. Therefore, in comparison, the storage type electric water heater can provide hot water with relatively stable temperature.

In the prior art, the storage type electric water heater is usually an electric-thermal pipe for directly heating the fluid stored in the water storage tank. Therefore, such a storage type electric water heater can generally only be used to heat a noncombustible fluid to prevent the fluid from being ignited upon heating to cause an accident. Furthermore, the wall temperature of the electric heating tube is relatively high. Therefore, when the electric heating tube is used to heat the fluid, the impurities in the fluid are liable to adhere to the tube wall of the electric heating tube, and the quality of the impurities attached to the tube wall also follows. Gradually increase with the use of time. Therefore, such a storage type electric water heater is less suitable for heating food grade fluids. In addition, the impurities accumulated on the wall of the electric heating pipe not only affect the heating efficiency of the electric heating pipe, but also shorten the service life of the electric heating pipe.

In order to improve the above problems, some of the water storage type electric water heaters use a heat pump instead of the electric heating tube, so that the high temperature refrigerant provided by the heat pump is stored in the water storage tank through a coil pipe. The fluid is heated indirectly. Similarly, the temperature of the refrigerant in the coil is high, so when the fluid and the refrigerant exchange heat through the wall of the coil, impurities in the fluid easily adhere to the wall of the tube, and the quality of impurities attached to the wall of the tube also follows. Gradually increase with the use of time. Moreover, if the wall of the coil is broken, the refrigerant easily permeates the wall of the tube to contaminate the fluid.

In addition, in the prior art, the high-temperature fluid that has been heated in the water storage tank is easily mixed with the low-temperature fluid replenished into the water storage tank to cool down, thereby making the amount of the high-temperature fluid actually usable smaller than the water storage capacity of the water storage tank. . Therefore, the water storage capacity of the water storage tank is usually high, and the temperature of the fluid stored in the water storage tank is high. However, high water storage must consume higher energy to maintain fluid temperature. Moreover, the greater the difference between the fluid temperature and the outside temperature, the faster the heat is lost.

In order to solve the above problems, the present invention provides a water storage type electric water heater which can improve the phenomenon that impurities in the working fluid accumulate on the casing wall.

The invention provides a water storage type electric water heater for heating a first working fluid, and comprises a water storage tank, a first jacket pipe, a heating unit, and a second A cannula and a driving apparatus. The water storage tank is used to store a second working fluid. The first sleeve is in communication with the water reservoir. The heating unit is for heating a third working fluid. a second sleeve is in communication between the first sleeve and the heating unit, and a third working fluid is adapted to flow between the heating unit and the second sleeve, wherein the second sleeve is disposed in the second stored in the water storage tank Above the working fluid. The driving device is configured to drive the second working fluid stored in the water storage tank to flow into the second casing to exchange heat with the third working fluid, and then flow into the first casing to exchange heat with the first working fluid, and then Return to the water storage tank.

In an embodiment of the invention, the first sleeve includes an outer pipe and a plurality of inner pipes that are disposed in the outer tube. The first working fluid flows between the outer tube and the inner tubes, and the second working fluid flows into the inner tubes.

In an embodiment of the invention, the first working fluid and the second working fluid are The flow in the first sleeve is opposite.

In an embodiment of the invention, the second sleeve includes an outer tube and a plurality of inner tubes that are disposed in the outer tube. The second working fluid flows between the outer tube and the inner tubes, and the third working fluid flows into the inner tubes.

In an embodiment of the invention, the second working fluid and the third working fluid are opposite in flow direction in the second sleeve.

In an embodiment of the invention, the water storage type electric water heater further includes a connecting pipe. An inlet end of the connecting pipe passes through the water storage tank and extends into a second working fluid stored in the water storage tank, and an outlet end of the connecting pipe communicates with the driving device.

In an embodiment of the invention, the water storage tank further has an overflow vent, and the height of the inlet end is slightly lower than the height of the overflow opening.

In an embodiment of the invention, the water storage type electric water heater further includes a connecting pipe. An inlet end of the connecting tube communicates with the first sleeve, and an outlet end of the connecting tube extends toward the bottom of the water storage tank.

In an embodiment of the invention, the first sleeve is immersed in a second working fluid stored in a water storage tank.

In an embodiment of the invention, the water storage tank has an opening, and the heating unit covers the opening.

In an embodiment of the invention, the opening of the water storage tank has a first fitting portion around the opening, and a bottom portion of the heating unit has a second fitting portion, and the first fitting portion and the second fitting portion Fit each other.

In an embodiment of the invention, the drive device drives the second working fluid flow as the first working fluid flows through the first sleeve.

In an embodiment of the invention, when the heating unit is activated to heat the third work The drive device drives the second working fluid flow as a fluid.

In an embodiment of the invention, the water storage type electric water heater further includes an insulating material layer, and the heat insulating material layer covers the outer surface of the water storage tank.

In an embodiment of the invention, the heating unit is a heat pump.

In an embodiment of the invention, the driving device is a pump, which is disposed outside the water storage tank and communicates between the water storage tank and the second casing.

In an embodiment of the invention, the first working fluid is water.

In an embodiment of the invention, the second working fluid is water.

In an embodiment of the invention, the third working fluid is a refrigerant.

Based on the above, in the present invention, the amount of impurities attached to the first sleeve will be lower, and the amount of impurities attached to the second sleeve will not gradually increase with the use time. Therefore, the present invention can improve the accumulation of impurities in the working fluid on the casing wall to maintain better heating efficiency and longer service life.

The above described features and advantages of the invention will be apparent from the following description.

1 is a schematic structural view of a water storage type electric water heater according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line I-I of FIG. 1. In order to simplify the drawing, the internal structure of the heating device is omitted in FIG. Referring to FIG. 1 and FIG. 2, the water storage type electric water heater 100 is configured to heat a first working fluid, and includes a water storage tank 110, a first sleeve 120a, a second sleeve 120b, and a heating unit 130. And a driving device 140. The first sleeve 120a is in communication with the water storage tank 110, and the second sleeve 120b is in communication with the first sleeve 120a and the heating unit 130, and a second working fluid is available in the water storage tank 110, the first sleeve 120a flows between the second sleeve 120b.

The heating unit 130 can heat a third working fluid, and the heated third working fluid can flow into the second sleeve 120b. Moreover, the driving device 140 can be disposed outside the water storage tank 110 and can communicate between the water storage tank 110 and the second sleeve 120b. Therefore, after the driving device 140 is activated, the second working fluid stored in the water storage tank 110 can be driven to flow into the second sleeve 120b to exchange heat with the third working fluid. Then, the second working fluid will flow into the first sleeve 120a to exchange heat with the first working fluid. Then, the second working fluid is again returned to the storage tank 110 for storage, and the first working fluid flows out of the storage-type electric water heater 100 for use by the user.

In this embodiment, the heating unit 130 is, for example, a heat pump, and the driving device 140 is, for example, a pump. Furthermore, the first working fluid is, for example, tap water, and the second working fluid is, for example, water stored in the water storage tank 110 for use as a heat medium, and the third working fluid is, for example, stored. The refrigerant in the heat pump. In order to enable those skilled in the art to implement according to the following embodiments, in the following embodiments, the first working fluid, the second working fluid and the third working fluid will be respectively tap water, heat medium water and The refrigerant is illustrated. However, the first working fluid, the second working fluid, and the third working fluid are not limited to the following embodiments.

In more detail, the water storage type electric water heater 100 further includes a first connecting pipe 150, a second connecting pipe 160, and an overflow port 170. An inlet end 150a of the first connecting pipe 150 extends through the water storage tank 110 to the heat medium water stored in the water storage tank 110, and its height is slightly lower than the height of the overflow port 170, and one of the first connecting pipes 150 The outlet end 150b is in communication with the drive unit 140. Furthermore, an inlet end 160a of the second connecting tube 160 communicates with the first sleeve 120a, and an outlet end 160b of the second connecting tube 160 extends toward the bottom of the water storage tank 110. In general, the density of hot water will be less than the density of cold water, so higher temperature water will flow towards higher water levels. Therefore, the inlet end 150a of the first connecting pipe 150 extends to the high temperature heat medium water, and the outlet end 160b of the second connecting pipe 160 extends to the low temperature heat medium water.

When the tap water flows into the first sleeve 120a via an inlet line 180a, the driving device 140 is activated to drive the higher temperature heat medium water in the water storage tank 110 to sequentially flow through the first connecting tube 150 and drive through the inlet end 150a. The device 140 and the second sleeve 120b flow into the first sleeve 120a to heat the tap water. At the same time, the heated tap water will flow out of the storage type electric water heater 100 via an outlet line 180b for use by the user. Moreover, the low temperature heat medium water heated by the tap water is discharged to the bottom of the water storage tank 110 via the outlet end 160b of the second connecting pipe 160 to prevent it from being mixed with the high temperature heat medium water at the high water level in the water storage tank 110. The overall temperature of the heat medium water in the water storage tank 110.

Moreover, when the heat medium water in the water storage tank 110 is cooled to a critical temperature as the tap water is heated, the heating unit 130 is activated to heat the refrigerant. The critical temperature may be a factory preset value set by the manufacturer, or may be set by the user according to the usage requirements thereof. At the same time, the heated refrigerant flows into the second sleeve 120b to heat the heat medium water flowing into the second sleeve 120b, thereby maintaining the temperature of the heat medium water flowing into the first sleeve 120a. In this way, the tap water heated by the heat medium water can be continuously maintained at a relatively high temperature.

In addition, when the low temperature tap water does not flow in from the inlet line 180a, and the temperature of the heat medium water stored in the water storage tank 110 falls below the critical temperature, the heating unit 130 and the driving device 140 are simultaneously activated. At this time, the heating unit 130 heats the hot medium water flowing into the second sleeve 120b through the refrigerant, and injects the heated heat medium water into the water storage tank 110 through the first sleeve 120a until it is stored in the water storage tank 110. The temperature of the heat medium water is higher than a set temperature. The set temperature may be higher than the critical temperature, and the set temperature may be a factory preset value set by the manufacturer, or may be set by the user according to the use requirements thereof.

Briefly, when low temperature tap water flows in from the inlet line 180a, and the temperature of the heat medium water in the water storage tank 110 is high, the water storage type electric water heater 100 can directly heat the tap water through the heat medium water. However, when the temperature of the heat medium water in the water storage tank 110 is low, the heating unit 130 first heats the heat medium water through the refrigerant, and the heated heat medium water directly flows into the first sleeve 120a to Heat tap water. Moreover, the water storage type electric water heater 100 determines whether the temperature of the heat medium water is lower than the critical temperature to determine whether to activate the heating unit 130 to heat the heat medium water.

Therefore, compared to the prior art, it is necessary to store a large amount of high-temperature tap water in the water storage tank, and the present invention only needs to store a small amount and a lower temperature of the heat medium water in the water storage tank 110, that is, the tap water that can be heated continuously. Maintain at a higher temperature. That is to say, the water storage tank 110 of the present invention can release more high-temperature tap water with the same storage amount as compared with the prior art. It is worth noting that the lower the temperature, the slower the heat dissipation rate. Moreover, the less the amount of fluid stored in the water storage tank 110, the less energy is required to maintain the fluid temperature. Therefore, the water storage type electric water heater 100 of the present invention is more energy efficient than the prior art. In addition, the outer surface of the water storage tank 110 may be covered with a layer of insulating material 190 to further reduce the heat loss of the heat medium water.

In addition, the tap water is directly heated by the electric heating tube compared to the prior art, or the tap water is indirectly heated by the heat pump. In the present invention, the heating unit 130 transmits the third working fluid and the second working fluid at a lower level. The temperature indirectly heats the first working fluid. Therefore, the water storage type electric water heater 100 can be used not only to heat a non-flammable fluid but also to heat a flammable fluid. Further, by heating the tap water at a lower temperature, the amount of impurities precipitated from the tap water can be further reduced, and the amount of impurities attached to the first sleeve 120a with the use time is also low. Therefore, the first sleeve 120a can maintain better heating efficiency and longer service life than the prior art.

Further, in the present invention, the heat medium water and the refrigerant medium are continuously recycled without being frequently replenished. Therefore, the amount of impurities of the heat medium water and the refrigerant is substantially no longer increased after the assembly of the water storage type electric water heater 100 is completed. In other words, the heat medium water and the refrigerant do not continuously precipitate impurities along with the use time, and the amount of impurities attached to the second sleeve 120b does not gradually increase with the use time. Therefore, the second sleeve 120b can also maintain better heating efficiency and a longer service life.

In addition, when the first sleeve 120a is broken, the leaked third working fluid will only flow into the second working fluid without contaminating the first working fluid. In addition, when the second sleeve 120b is broken, the leaked second working fluid may be mixed into the first working fluid, but the first work can be avoided by using the first working fluid and the second working fluid having substantially the same composition. The problem of fluid contamination. In other words, the problem that the leaked third working fluid contaminates the first working fluid occurs only when both the first sleeve 120a and the second sleeve 120b are broken. However, the probability of both the first sleeve 120a and the second sleeve 120b breaking is extremely low. Therefore, the water storage type electric water heater 100 can be used to heat food grade fluids.

In addition, the water storage tank 110 in this embodiment may be an open water storage tank, and the heating unit 130 may cover an opening 112 of the water storage tank 110. In more detail, the opening 112 of the water storage tank 110 may have a first fitting portion 114, for example, a recess, and a bottom portion of the heating unit 130 may have a second fitting portion 132, for example, a Flange. Moreover, the second fitting portion 132 can bear against the first fitting portion 114 to be fitted to the first fitting portion 114. In this way, not only the external impurities can be prevented from falling into the water storage tank 110 through the opening 112, but also the heat dissipation speed of the heat medium water can be reduced. Moreover, the condensed water condensed thereon when the heating unit 130 heats the refrigerant may also be directly dropped into the water storage tank 110 to replenish the heat medium water evaporated by the heating in the water storage tank 110.

As shown in FIG. 2, in this embodiment, the first sleeve 120a is immersed in the higher temperature heat medium water stored in the water storage tank 110, and is disposed by an outer tube OP and a plurality of outer tubes OP. The inner tube is composed of IP. Moreover, tap water flows between the outer tube OP and the inner tubes IP, and the heat medium water flows into the inner tubes IP, and the flow direction of the tap water and the heat medium water is opposite. In this way, the internal pipe IP not only has a large heat transfer area, but the tap water and the heat medium water also form a turbulent state due to the large flow resistance, so as to increase the time and uniformity of the heat medium water heating the tap water. . In addition, the tap water can be heated not only by the heat medium water in the inner tube IP but also by the heat medium water in the water storage tank 110. Therefore, compared with the prior art in which the tap water is directly heated by the high-temperature refrigerant, although the present invention heats the tap water with the lower temperature heat medium water, good heating efficiency can be maintained.

Similarly, in this embodiment, the second sleeve 120b may also be composed of an outer tube OP and a plurality of inner tubes IP penetrating the outer tube OP. Further, the heat medium water flows between the outer tube OP and the inner tubes IP, and the refrigerant flows into the inner tubes IP, and the flow direction of the heat medium water and the refrigerant is opposite. In this way, the internal pipe IP not only has a large heat transfer area, but the heat medium water and the refrigerant medium also form a turbulent state due to the large flow resistance, so as to increase the time and uniformity of the refrigerant heating the heat medium water. . In addition, in this embodiment, the second sleeve 120b is disposed on the heat medium water stored in the water storage tank 110 to prevent the heat medium water heated by the refrigerant in the second sleeve 120b from contacting the water storage tank 110. The temperature is lowered by the heat medium water before the refrigerant is heated.

In addition, in other embodiments not shown, the water storage type electric water heater may further include an external water storage tank. The external water storage tank can be connected to an outlet line for storing the heated first working fluid. Alternatively, the external water storage tank may be connected to the water storage tank for storing more second working fluid. Alternatively, the drive means may be a variable frequency pump to adjust the flow rate of the second working fluid by varying the motor speed of the variable frequency pump. Alternatively, the drive unit may be a fixed frequency pump and used in conjunction with a ball valve, an electronic ball valve, or the like that can be used to vary the flow rate of the second working fluid.

At this time, the water storage type electric water heater can adjust the flow rate of the second working fluid according to the flow rate of the first working fluid, thereby adjusting the time for the second working fluid to heat the first working fluid. Alternatively, when the temperature of the second working fluid stored in the water storage tank is high, the driving device may also increase the flow rate of the second working fluid to shorten the third working fluid to heat the second working fluid and the second working fluid to heat the first The time of working fluid. In addition, when the temperature of the second working fluid stored in the water storage tank and the outside temperature are both low, the driving device can also reduce the flow rate of the second working fluid. At this time, not only the time during which the third working fluid heats the second working fluid and the second working fluid heats the first working fluid may be extended, so as to increase the temperature of the first working fluid after heating, and the third working fluid may be maintained at a higher level. The temperature is to avoid frosting or freezing of the heating unit.

In summary, the water storage type electric water heater of the present invention can have at least the following advantages:

1. The water storage tank can release more high temperature first working fluid with the same storage amount.

2. The water storage tank can store a smaller amount and a lower temperature second working fluid to save energy required to maintain the temperature of the second working fluid.

3. Indirectly heating the first working fluid through the third working fluid and the second working fluid at a lower temperature to reduce the amount of impurities precipitated from the tap water, thereby reducing the amount of impurities attached to the first sleeve with the use time. Therefore, the first sleeve can maintain better heating efficiency and a longer service life.

4. The second working fluid and the third working fluid are recycled so that the amount of impurities attached to the second sleeve does not gradually increase with time of use, so the second sleeve can maintain better heating efficiency. And a long service life.

5. The storage type electric water heater can not only be used to heat non-flammable fluids, but also to heat flammable fluids, and can also be used to heat food-grade fluids.

6. The water storage tank can use an open water storage tank to prevent the pressure on the water storage tank from increasing gradually as the temperature of the second working fluid rises, thereby avoiding the problem of cracking or water leakage in the water storage tank.

7. The heating unit is disposed on the water storage tank, and can be used not only to prevent external impurities from falling into the water storage tank through the opening, but also to reduce the heat loss rate of the heat medium water, and the condensation water condensed on the heating unit when heating the refrigerant. It can also be directly dripped into the water storage tank to supplement the heat medium water evaporated by heating in the water storage tank.

8. After heating, the third working fluid heated by the heating unit directly flows into the second casing to heat the second working fluid, and the heated second working fluid flows directly into the first casing to The first working fluid is heated and the first sleeve is immersed in the second working fluid at a higher temperature, thereby maintaining a preferred heating efficiency for the first working fluid.

9. Discharge the low temperature second working fluid heated through the first working fluid to the bottom of the water storage tank to avoid mixing it with the high temperature second working fluid to lower the overall temperature of the second working fluid in the water storage tank.

10. A plurality of inner tubes can be formed in the first sleeve and the second sleeve to increase the heat transfer area and to form a turbulent state of the working fluid to increase the heat transfer time and uniformity between the working fluids. degree.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and those skilled in the art can make some modifications and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

100. . . Storage water heater

110. . . Water storage tank

112. . . Opening

114. . . First fitting

120a. . . First casing

120b. . . Second casing

130. . . Heating unit

132. . . Second fitting part

140. . . Drive unit

150. . . First connecting pipe

150a, 160a. . . Import side

150b, 160b. . . Exit end

160. . . Second connecting pipe

170. . . Overflow

180a. . . Import pipeline

180b. . . Export pipeline

190. . . Insulation material layer

IP. . . Inner tube

OP. . . Outer tube

FIG. 1 is a schematic structural view of a water storage type electric water heater according to an embodiment of the present invention.

Figure 2 is a cross-sectional view taken along line I-I of Figure 1.

100. . . Storage water heater

110. . . Water storage tank

112. . . Opening

114. . . First fitting

120a. . . First casing

120b. . . Second casing

130. . . Heating unit

132. . . Second fitting part

140. . . Drive unit

150. . . First connecting pipe

150a, 160a. . . Import side

150b, 160b. . . Exit end

160. . . Second connecting pipe

170. . . Overflow

180a. . . Import pipeline

180b. . . Export pipeline

190. . . Insulation material layer

Claims (19)

A water storage type electric water heater for heating a first working fluid, the water storage type electric water heater comprising: a water storage tank for storing a second working fluid; a first casing connected to the water storage tank; a heating unit for heating a third working fluid; a second sleeve connected between the first sleeve and the heating unit, and the third working fluid is adapted to be in the heating unit and the second sleeve Flowing between wherein the second sleeve is disposed on the second working fluid stored in the water storage tank; and a driving device for driving the second working fluid to flow into the second set from the water storage tank The tube exchanges heat with the third working fluid, and then flows into the first sleeve to exchange heat with the first working fluid, and then flows back into the water storage tank. The water storage type electric water heater according to claim 1, wherein the first sleeve comprises an outer tube and a plurality of inner tubes passing through the outer tube, the first working fluid flowing to the outer tube and the Between the inner tubes, and the second working fluid flows in the inner tube. The water storage type electric water heater according to claim 2, wherein a flow direction of the first working fluid and the second working fluid in the first sleeve is opposite. The water storage type electric water heater according to claim 1, wherein the second sleeve comprises an outer tube and a plurality of inner tubes passing through the outer tube, the second working fluid flowing to the outer tube and the Between the inner tubes, and the third working fluid flows in the inner tube. The water storage type electric water heater according to claim 4, wherein the second working fluid and the third working fluid flow in the second sleeve in opposite directions. The water storage type electric water heater according to claim 1, further comprising a connecting pipe, wherein an inlet end of the connecting pipe passes through the water storage tank and extends to the second working fluid stored in the water storage tank, and An outlet end of the connecting tube is in communication with the driving device. The water storage type electric water heater according to claim 6, wherein the water storage tank further has an overflow port, and the height of the inlet end is slightly lower than the height of the overflow port. The water storage type electric water heater according to claim 1, further comprising a connecting pipe, wherein an inlet end of the connecting pipe communicates with the first bushing, and an outlet end of the connecting pipe extends toward a bottom of the water storage tank. The water storage type electric water heater according to claim 1, wherein the first casing is immersed in the second working fluid stored in the water storage tank. A water storage type electric water heater according to claim 1, wherein the water storage tank has an opening, and the heating unit covers the opening. The water storage type electric water heater according to claim 10, wherein the opening of the water storage tank has a first fitting portion around the opening, and a bottom portion of the heating unit has a second fitting portion, and the first fitting portion The portion and the second fitting portion are fitted to each other. The water storage type electric water heater according to claim 1, wherein the driving device drives the second working fluid to flow when the first working fluid flows through the first casing. The storage type electric water heater according to claim 1, wherein the driving device drives the second working fluid to flow when the heating unit is activated to heat the third working fluid. The water storage type electric water heater according to claim 1, further comprising a heat insulating material layer, wherein the heat insulating material layer covers the outer surface of the water storage tank. The water storage type electric water heater according to claim 1, wherein the heating unit is a heat pump. The water storage type electric water heater according to claim 1, wherein the driving device is a pump, which is disposed outside the water storage tank and communicates between the water storage tank and the second casing. The water storage type electric water heater according to claim 1, wherein the first working fluid is water. The storage-type electric water heater according to claim 1, wherein the second working fluid is water. The storage-type electric water heater according to claim 1, wherein the third working fluid is a refrigerant.