US20220205682A1

US20220205682A1 - Smart circulation control instantaneous-heating storage heat exchanger

Info

Publication number: US20220205682A1
Application number: US17/137,351
Authority: US
Inventors: Ho-Jen Wu
Original assignee: Dong Yong Hot Water System Inc
Current assignee: Dong Yong Hot Water System Inc
Priority date: 2020-12-30
Filing date: 2020-12-30
Publication date: 2022-06-30

Abstract

A smart circulation control instantaneous-heating storage heat exchanger includes a heat exchanger, a cold-water pipe, a hot-water pipe, an internal circulation pipe, and a control unit. The heat exchanger includes a storage space. The internal circulation pipe includes a two-way valve and a circulation pump. The control unit is connected to the two-way valve and the circulation pump. The internal circulation pipe functions to return a part of heated water back to the storage space to enhance thermal conversion efficiency and save energy and improve controllability. Positions for supplying cold water and returning water are made at different sites, and the circulation pump and the internal circulation pipe are used to selectively execute functions of anti-freezing, pre-heating, and heat balancing. An external circulation pipe is additionally included such that by means of the two-way valve and the circulation pump, switching can be made between internal and external circulations.

Description

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a heat exchanger, and more particularly to an instantaneous-heating storage heat exchanger combined with smart circulation control to enhance the thermal conversion efficiency thereof.

DESCRIPTION OF THE PRIOR ART

Referring to FIG. 5, a known tankless instant water heater 90 is structured to heat a cold-water pipe 91 to a predetermined temperature. Due to a great difference of temperature between cold water and heated water, the consumption of energy is great and the control of temperature is difficult, making it hard to supply a large quantity of heated water in a very short period of time.
Further, the known instant water heater 90 includes, arranged in the interior thereof, a coiled pipeline 92, which once being applied to an enlarged size, would not be effective for desired exchange of heat. Consequently, the size of the coiled pipeline 92 is subject to constraint and cannot supply an increased quantity of heated water simply by raising pressure.
Referring to FIG. 6, the known instant water heater 90 is additionally provided with a water circulation pipe 93. Although a cold-water inlet port of the cold-water pipe 91 and an external water inlet port of the water circulation pipe 93 seem different when observed from outside of the known instant water heater 90, the two are in fact set in communication with each other in the interior of the known instant water heater 90. Consequently, water circulation and water feed-out cannot be put into operation at the same time, as this would affect the control of temperature.
Referring to FIG. 7, a different known water heater 80 has a water-circulating pre-heating system, which includes a pump 81 and an external circulation pipe 82. In practice, pre-heating is achieved by means of the pump 81 and the external circulation pipe 82.
In view of the above, the known water control configurations of water heater require further improvements.

SUMMARY OF THE INVENTION

An objective of the present invention is to provide a smart circulation control instantaneous-heating storage heat exchanger to enhance thermal conversion efficiency.
To achieve the above objective, the present invention comprises a heat exchanger, a cold-water pipe, a hot-water pipe, an internal circulation pipe, and a control unit, wherein the heat exchanger is arranged in an interior of a water heater, the heat exchanger comprising a heat source supply structure and a storage space, the heat source supply structure heating cold water contained in the storage space to convert into hot water; the cold-water pipe is connected to the heat exchanger at a first position to supply cold water into the storage space; the hot-water pipe is connected to the heat exchanger at a second position to discharge the hot water generated in the storage space; the internal circulation pipe is disposed in the interior of the water heater, the internal circulation pipe having two ends that are respectively connected to the hot-water pipe and the storage space to allow hot water contained in the hot-water pipe to return back to the storage space to enhance thermal conversion efficiency, the internal circulation pipe being combined with a two-way valve and a circulation pump; and the control unit is connected to the two-way valve and the circulation pump to control a passage channel of the two-way valve to be in an open state or a closed state and also to control a flow rate of the circulation pump.
The function and efficacy of the above heat exchanger are as follows:
(1) an arrangement that features both an instant device and a storage (tank involved) device, wherein since the storage has a large capacity of storage, heating can be made to a large quantity of water at the same time and it is also possible to supply a large quantity of hot water, and increasing water discharge rate can easily made by simply expanding a water inlet port or a water outlet port; and
(2) location water introduction with a cold-water pipe being different from location of water returning with an internal circulation pipe, such that temperature balance may be made inside the storage space for the cold water and the returned hot water, without affecting temperature control, and also allowing simultaneous operations for external pipe pre-heating and water supplying.
The function and efficacy of the internal circulation pipe and the circulation pump comprises are as follows:
(1) a part of discharged hot water being returned back to the storage space to increase the temperature of cold water thereby reducing a temperature difference between the cold water and a preset temperature and a desired temperature can be reached by heating with a lowered consumption of energy, achieving high thermal conversion efficiency and saving energy, and ease control of temperature due to reduced temperature difference; and
(2) no external water circulation pipe being required, for the internal circulation is sufficient for performance of pre-heating and anti-freezing functions and supplying of a large quantity of hot water in a short period of time.
Another objective of the present invention is to provide a smart circulation control instantaneous-heating storage heat exchanger, which allows for selecting and switching between internal circulation and external circulation.
To achieve such another objective, the present invention further comprises an external circulation pipe, wherein two ends of the external circulation pipe are respectively connected to the hot-water pipe and the internal circulation pipe.
By means of a control system formed of the two-way valve and the control unit, switching of flow line between the internal circulation pipe and the external circulation pipe can be made. In demand of hot water, the control system switches to the internal-circulation-pipe flow line, so that the internal circulation may be used to reduce a temperature difference and thus enhance thermal conversion efficiency, lowers energy loss, and reduces internal latent heat related phenomenon of the storage space. In case of no hot water demand, the control system switches to the internal-circulation-pipe flow line, so that the internal circulation may be used for pre-heating and anti-freezing. Or alternatively, the control system switches to the external-circulation-pipe flow line, so that the external circulation may provide functions of external circulation pipe pre-heating and anti-freezing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating a first example of use of the present invention.

FIG. 2 is a block diagram illustrating a second example of use of the present invention.

FIG. 3 is a block diagram illustrating a third example of use of the present invention.

FIG. 4 is a cross-sectional view illustrating a storage space being divided into a high-temperature zone, a low-temperature zone, and mixed-temperature zone according to the present invention.

FIG. 5 is a diagram illustrating a first example of use of a known instant water heater.

FIG. 6 is a diagram illustrating a second example of use of the known instant water heater.

FIG. 7 is a diagram illustrating an example of use of another known instant water heater.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, the present invention comprises a heat exchanger 10, a cold-water pipe 20, a hot-water pipe 30, an internal circulation pipe 40, and a control unit 50, of which details are provided below.
The heat exchanger 10 is arranged in an interior of a water heater 11. The heat exchanger 10 comprises a heat source supply structure 12 and a storage space 13. The heat source supply structure 12 is operable to heat and convert cold water contained in the storage space 13 into hot water.
In the drawings, the wavy pattern hatching indicates water contained in the storage space 13 and thicker and darker part of the hatching indicates water having a relatively high temperature at such a location.
The cold-water pipe 20 is connected to the heat exchanger 10 at a first position in order to feed cold water into the storage space 13.
The hot-water pipe 30 is connected to the heat exchanger 10 at a second position in order to feed out hot water generated in the storage space 13.
The internal circulation pipe 40 is disposed in the interior of the water heater 11. The internal circulation pipe 40 has two ends that are respectively connected to the hot-water pipe 30 and the storage space 13 in order to return hot water contained in the hot-water pipe 30 back to the storage space 13. The internal circulation pipe 40 is combined with a two-way valve 41 and a circulation pump 42.
The internal circulation pipe 40 functions to form an internal-circulation-pipe flow line to realize internal circulation.
The control unit 50 is connected to the two-way valve 41 and the circulation pump 42 in order to control a passage channel of the two-way valve 41 to be in an open state or a closed state and also to control a flow rate of the circulation pump 42.
Referring to FIG. 3, in an embodiment, the present invention may further comprise an external circulation pipe 60. The external circulation pipe 60 has two ends that are respectively connected to the hot-water pipe 30 and the internal circulation pipe 40 in order to selectively switch to an external-circulation-pipe flow line to realize external circulation.
With a control system so formed of the two-way valve 41 and the control unit 50, switching the flow line between the internal circulation pipe 40 and the external circulation pipe 60.
Referring again to FIG. 1, in an embodiment, the heat source supply structure 12 comprises an air blower 121, a burner 122, and a heat exchange pipe 123. The air blower 121 supplies a fuel gas and air into the burner 122 for burning to generate a heat source. The burner 122 generates combusted gas that enters the heat exchange pipe 123 to allow the heat exchange pipe 123 to heat water contained in the storage space 13.
In an embodiment, a temperature sensor 43 is mounted to a part of the internal circulation pipe 40 located between the two-way valve 41 and the circulation pump 42. The temperature sensor 43 is connected to the control unit 50, so that a water temperature sensed by the temperature sensor 43 is transmitted to the control unit 50 to allow the control unit 50 to signal and thus control and regulate the flow rate of the circulation pump 42 or to control and regulate a heating value provided by the heat source supply structure 12.
In an embodiment, the control unit 50 may be a controller including a control circuit board that enables setting of parameters and instructions for signaling and thus controlling the two-way valve 41 and the circulation pump 42.
In an embodiment, the connection of the cold-water pipe 20 to the heat exchanger 10 is provided, at the connection site at first position, with a water inlet connector 21, which eases mounting/removing and replacement of the cold-water pipe 20; the connection of the hot-water pipe 30 to the heat exchanger 10 is provided, at the connection site at the second position, with a hot-water connector 31, which eases mounting/removing and replacement of the hot-water pipe 30; and the connection of the internal circulation pipe 40 to the storage space 13 is provided, at the site of connection, with a circulation connector 44, which eases mounting/removing and replacement of the internal circulation pipe 40.
The above provides a description to the parts/components of the present invention and the assembly thereof, and in the following, examples of use, features, and advantages of the present invention will be described.
Referring to FIG. 1, in a state that the water heater 11 is in operation to supply hot water for daily living (where no outside-arranged external circulation pipe is involved):
cold water flows through the water inlet connector 21 into the heat exchanger 10 and is subject to heat exchange inside the storage space 13 to provide hot water, which is discharged from the hot-water connector 31.
In a condition of continuous supply of hot water, the control system made up of the two-way valve 41 and the control unit 50 switches or sets the two-way valve 41 to an internal circulation mode, in which the internal circulation pipe 40 is opened and the circulation pump 42 is kept in continuous operation to cause hot water to flow at a rate of 1-5 liters per minute through the circulation connector 44 to return back into the heat exchanger 10, such that cold water contained in the storage space 13 is mixed with the hot water so returned to cause rise of temperature, wherein the temperature sensor 43 senses the rise of internal temperature of the storage space 13, indicating there is no extra supply of thermal energy, with which automatic regulation and reduction of the supply of thermal energy is made.
Referring to FIG. 4, when the external demand for water is terminated, the internal circulation mode that is established with the flow line involving the circulation pump 42 and the internal circulation pipe 40 maintains operation for a period of 30 second, so that during such a period, temperatures of a high-temperature zone 131 and a low-temperature zone 133 inside the storage space 13 are mixed uniformly to form a mixed-temperature zone 132, which helps prevents concentration of thermal stress caused by latent heat of the high-temperature zone 131 on an upper portion of the heat exchanger 10 to cause latent heat deformation in the material of the heat exchanger 10, which destructs structural stiffness and affects the durability thereof.
Referring to FIG. 2, in a state that the water heater 11 is kept still and in an idle condition, where no outside-arranged external circulation pipe may be involved, the two-way valve 41 can be selectively switched to the internal circulation configuration.
Referring to FIG. 3, the water heater 11 is kept still and in an idle condition, but with the external circulation pipe 60 involved, the two-way valve 41 can be selectively switched to the external circulation configuration.
In the internal circulation configuration and the external circulation configuration respectively shown in FIGS. 2 and 3, the present invention can be selectively set at the following mode:
(1) Anti-freezing mode (5° C.): the internal circulation or the external circulation is kept at a non-freezing temperature.
Activation of heating in anti-freezing mode=the temperature sensor 43 sensing temperature being persistently lower than 5° C. for a period of 10 seconds, and the internal circulation or the external circulation activated to perform heating with a minimum required level of energy.
Deactivation of heating in anti-freezing mode=anti-freezing temperature (which is set for a default value of 5° C.)+increase of temperature (which is set for a default value of 5° C.).
(2) Pre-heating mode: the internal circulation or the external circulation maintains at a temperature of hot water sufficient for daily living.
Activation of heating in pre-heating mode=the temperature sensor 43 sensing temperature being persistently lower than a pre-heating activation setting value for a period of 10 seconds, and the internal circulation or the external circulation activated for operation and performing heating with a minimum required level of energy.
Deactivation of heating in pre-heating mode=daily living hot water temperature setting value+increase of temperature (which is set for a default value of 0° C.).
(3) Energy-saving mode: the internal circulation or the external circulation maintains daily living water supply at a normal or room temperature.
Activation of heating in energy-saving mode=the temperature sensor 43 sensing temperature being persistently lower than an energy-saving activation setting value (which is set for a default value of 25° C.) for a period of 10 seconds, and the internal circulation or the external circulation activated for operation and performing heating with a minimum required level of energy.
Deactivation of heating in energy-saving mode=energy-saving temperature setting value (which is set for a default value of 30° C.)+increase of temperature (which is set for a default value of 0° C.).
When there is a demand for hot water for daily living in a condition when the present invention is set in the anti-freezing mode, the pre-heating mode, or the energy-saving mode, the present invention automatically switches to a condition of supply, as priority, hot water for daily living.
In a preferred operation, the above-described anti-freezing, pre-heating, and energy-saving modes of the present invention is selectively activated by just one among the others.

Claims

I claim:

1. A smart circulation control instantaneous-heating storage heat exchanger, comprising:

a heat exchanger, which is arranged in an interior of a water heater, the heat exchanger comprising a heat source supply structure and a storage space, wherein the heat source supply structure heats cold water contained in the storage space to convert into hot water,

a cold-water pipe, which is connected to the heat exchanger at a first position to supply cold water into the storage space;

a hot-water pipe, which is connected to the heat exchanger at a second position to discharge the hot water generated in the storage space;

an internal circulation pipe, which is disposed in the interior of the water heater, the internal circulation pipe having two ends that are respectively connected to the hot-water pipe and the storage space to allow hot water contained in the hot-water pipe to return back to the storage space to enhance thermal conversion efficiency, the internal circulation pipe being combined with a two-way valve and a circulation pump; and

a control unit, which is connected to the two-way valve and the circulation pump to control a passage channel of the two-way valve to be in an open state or a closed state and also to control a flow rate of the circulation pump.

2. The smart circulation control instantaneous-heating storage heat exchanger according to claim 1, further comprising an external circulation pipe, the external circulation pipe having two ends that are respectively connected to the hot-water pipe and the internal circulation pipe to selectively switch to an external-circulation-pipe flow line to realize external circulation, such that a control system formed of the two-way valve and the control unit is operable to switch a flow line between the internal circulation pipe and the external circulation pipe.

3. The smart circulation control instantaneous-heating storage heat exchanger according to claim 1, wherein the heat source supply structure comprises an air blower, a burner, and heat exchange pipe, wherein the air blower supplies a fuel gas and air to the burner for burning to generate heat, combusted gas generated in the burner and entering the heat exchange pipe to allow the heat exchange pipe to heat the cold water contained in the storage space.

4. The smart circulation control instantaneous-heating storage heat exchanger according to claim 1, wherein a temperature sensor is mounted to the internal circulation pipe between the two-way valve and the circulation pump, and the temperature sensor is connected to the control unit, so that a water temperature sensed by the temperature sensor is transmitted to the control unit to allow the control unit to control and regulate a flow rate generated by the circulation pump or to control and regulate a heating value provided by the heat source supply structure.

5. The smart circulation control instantaneous-heating storage heat exchanger according to claim 1, wherein the control unit comprises a controller including a control circuit board that enables setting of parameters and instructions for controlling the two-way valve and the circulation pump.

6. The smart circulation control instantaneous-heating storage heat exchanger according to claim 1, wherein the connection of the cold-water pipe to the heat exchanger comprises a water inlet connector installed at the first position to ease mounting and assembling and replacement of the cold-water pipe; the connection of the hot-water pipe to the heat exchanger comprises a hot-water connector installed at the second position to ease mounting and assembling and replacement of the hot-water pipe; and the connection of the internal circulation pipe to the storage space comprises a circulation connector installed at a connection site thereof to ease mounting and assembling and replacement of the internal circulation pipe.

7. The smart circulation control instantaneous-heating storage heat exchanger according to claim 2, wherein the heat source supply structure comprises an air blower, a burner, and heat exchange pipe, wherein the air blower supplies a fuel gas and air to the burner for burning to generate heat, combusted gas generated in the burner and entering the heat exchange pipe to allow the heat exchange pipe to heat the cold water contained in the storage space.

8. The smart circulation control instantaneous-heating storage heat exchanger according to claim 2, wherein a temperature sensor is mounted to the internal circulation pipe between the two-way valve and the circulation pump, and the temperature sensor is connected to the control unit, so that a water temperature sensed by the temperature sensor is transmitted to the control unit to allow the control unit to control and regulate a flow rate generated by the circulation pump or to control and regulate a heating value provided by the heat source supply structure.

9. The smart circulation control instantaneous-heating storage heat exchanger according to claim 2, wherein the control unit comprises a controller including a control circuit board that enables setting of parameters and instructions for controlling the two-way valve and the circulation pump.

10. The smart circulation control instantaneous-heating storage heat exchanger according to claim 2, wherein the connection of the cold-water pipe to the heat exchanger comprises a water inlet connector installed at the first position to ease mounting and assembling and replacement of the cold-water pipe; the connection of the hot-water pipe to the heat exchanger comprises a hot-water connector installed at the second position to ease mounting and assembling and replacement of the hot-water pipe; and the connection of the internal circulation pipe to the storage space comprises a circulation connector installed at a connection site thereof to ease mounting and assembling and replacement of the internal circulation pipe.