Multifunctional water tank system based on heat pump unit and its control method

Abstract

The present invention relates to a multifunctional water tank system based on a heat pump unit and a control method thereof. The multifunctional water tank system based on the heat pump unit includes a water tank, a heat exchange coil, a shell-and-tube heat exchanger, a heat pump unit, a floor heating system, and a circulation water pump, wherein: the heat exchange coil and the shell-and-tube heat exchanger are respectively fixedly installed at the bottom and the upper middle part inside the water tank; the water inlet end of the heat exchange coil is connected to the water inlet of the water tank, and its water outlet end is connected to the shell-side water inlet end of the shell-and-tube heat exchanger; the shell-side water outlet end of the shell-and-tube heat exchanger is connected to the water outlet of the water tank; both ends of the tube side of the shell-and-tube heat exchanger are respectively connected to the refrigerant inlet and the refrigerant outlet of the water tank, and are connected to the heat pump unit through a heat preservation pipeline; the water tank, the circulation water pump, and the floor heating system are connected into a closed loop through a heat preservation pipeline. The present invention realizes the dual-supply requirement of heating and domestic hot water with one water tank, and has a more reasonable design and a lower manufacturing cost.

Description

Technical Field

[0001] The invention relates to the technical field of hot water tanks, and in particular to a multifunctional water tank system based on a heat pump unit and a control method thereof. Background Art

[0002] At present, existing floor heating water heaters usually need to meet users' floor heating needs while also meeting users' domestic hot water needs. To meet this dual-supply requirement, two water tanks need to be designed, one for floor heating and the other for domestic hot water. The water tank system of this floor heating water heater has a high manufacturing cost, and the two water tanks take up more installation space, and have higher requirements for the installation location. Summary of the invention

[0003] The present invention aims to solve the technical problems existing in the prior art. To this end, the present invention provides a multifunctional water tank system based on a heat pump unit with a more reasonable design and low manufacturing cost and a control method thereof.

[0004] The technical solution adopted by the present invention to solve its technical problem is:

[0005] A multifunctional water tank system based on a heat pump unit is provided, comprising a water tank, a heat exchange coil, a shell-and-tube heat exchanger, a heat pump unit, floor heating, and a circulating water pump, wherein: the heat exchange coil and the shell-and-tube heat exchanger are fixedly installed at the bottom and the middle and upper part of the water tank respectively; the water inlet end of the heat exchange coil is connected to the water inlet of the water tank, and the water outlet end thereof is connected to the shell-side water inlet end of the shell-and-tube heat exchanger; the shell-side water outlet end of the shell-and-tube heat exchanger is connected to the water outlet of the water tank; the two ends of the tube side of the shell-and-tube heat exchanger are respectively connected to the refrigerant inlet and the refrigerant outlet of the water tank, and are connected to the heat pump unit through an insulated pipe; the water tank, the circulating water pump, and the floor heating are connected to form a closed loop through the insulated pipe.

[0006] In a preferred embodiment of the multifunctional water tank system based on the heat pump unit provided by the present invention, it also includes a water temperature control system, which includes a water tank temperature sensor, a water outlet temperature sensor, an electromagnetic three-way valve and a controller and a hot water circulation pipeline, wherein: the water tank temperature sensor is arranged in the middle of the water tank; the electromagnetic three-way valve is arranged on the hot water pipeline connected to the water outlet of the water tank; one end of the hot water circulation pipeline is connected to the shell side water inlet end of the shell-and-tube heat exchanger, and the other end is connected to the electromagnetic three-way valve; the water outlet temperature sensor is arranged on the hot water pipeline and is located at the water inlet end of the electromagnetic three-way valve; the water tank temperature sensor, the water outlet temperature sensor, the electromagnetic three-way valve and the heat pump unit are all connected to the controller by electrical signals.

[0007] In a preferred embodiment of the multifunctional water tank system based on the heat pump unit provided by the present invention, a hot water circulation pump is further provided on the hot water circulation pipeline, and the hot water circulation pump is controlled in linkage with the electromagnetic three-way valve.

[0008] The present invention also provides a control method for a multi-functional water tank system based on a heat pump unit, and the control method is as follows:

[0009] When the water temperature sensor in the water tank detects that the water temperature in the water tank is lower than the set water temperature of the water tank, the controller controls the heat pump unit to start, and the water temperature in the water tank is heated to the set temperature by the shell-and-tube heat exchanger to meet the floor heating demand;

[0010] When the user uses hot water, the cold water first passes through the heat exchange coil, and the hot water in the water tank preheats and heats the cold water to warm water. When the water temperature sensor in the water tank detects that the water temperature in the water tank ≥ the set water temperature of the water tank, the heat pump unit is turned off, and the water in the water tank heats the warm water in the shell-and-tube heat exchanger. The heated water flows to the outlet water temperature sensor. If the water temperature ≥ the set outlet water temperature, it is directly supplied to the user for use; if the water temperature < the set outlet water temperature, the controller controls the electromagnetic three-way valve to switch the passage, and the water is introduced into the shell-and-tube heat exchanger from the hot water circulation pipeline, and at the same time controls the heat pump unit to start, and after being heated to the set outlet water temperature by the heat pump unit, it is supplied to the user for use.

[0011] Compared with the prior art, the beneficial effects of the multi-functional water tank system based on a heat pump unit and its control method provided by the present invention are: the present invention forms a closed cycle with the water in the water tank and the floor heating. The water in the water tank is only used for floor heating and not as the water source for the user's domestic hot water. The user's domestic hot water is preheated as cold water by designing a heat exchange coil in the water tank, and then the preheated warm water is heated to the set temperature by using a shell-and-tube heat exchanger and sent out, so as to realize the dual-supply demand of heating and domestic hot water with one water tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to these drawings, where:

[0013] Figure 1 is a schematic structural diagram of a multi-functional water tank system based on a heat pump unit provided by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0014] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0015] Example 1

[0016] This embodiment provides a multi-functional water tank system 1 based on a heat pump unit. As shown in the appendix Figure 1 it includes a water tank 101, a heat exchange coil 102, a shell-and-tube heat exchanger 103, a heat pump unit 104, a floor heating 105, and a circulation water pump 106, where:

[0017] The heat exchange coil 102 and the shell-and-tube heat exchanger 103 are respectively fixedly installed at the bottom inside the water tank 101 and the upper middle part inside the water tank 101; the water inlet end of the heat exchange coil 102 is connected to the water inlet of the water tank 101, and its water outlet end is connected to the shell-side water inlet end of the shell-and-tube heat exchanger 103; the shell-side water outlet end of the shell-and-tube heat exchanger 103 is connected to the water outlet of the water tank 101.

[0018] Both ends of the tube side of the shell-and-tube heat exchanger 103 are respectively connected to the refrigerant inlet and the refrigerant outlet of the water tank 101, and are connected to the heat pump unit 104 through a heat-insulating pipeline; the heat pump unit in this embodiment can select an air-source heat pump unit, and in other embodiments, other heat pump units can also be used, and the function is to use the refrigerant to heat the water in the water tank and / or the shell side of the shell-and-tube heat exchanger.

[0019] The water tank 101, the circulation water pump 106, and the floor heating 105 are connected into a closed loop through a heat-insulating pipeline.

[0020] In this embodiment, the water in the water tank is used as the heat source for floor heating, which is a closed loop and not for external supply such as domestic water. Compared with an open loop, the heat loss is small, the energy consumption is low, and the heating efficiency is high; at the same time, the water in the water tank can also preheat the cold domestic water through the heat exchange coil. When the user uses hot water, it is first preheated by the heat exchange coil, and then heated by the shell-and-tube heat exchanger and the heat pump unit to meet the user's hot water demand.

[0021] It should be noted that: the water tank is equipped with a water replenishing system (not shown in the figure) to supplement the water lost in the water tank.

[0022] Example 2

[0023] On the basis of Example 1, in order to meet the user's water temperature requirements, the multi-functional water tank system 1 based on a heat pump unit in this embodiment is also designed with a water temperature control system. The water temperature control system includes a water tank temperature sensor 107, a water outlet temperature sensor 108, an electromagnetic three-way valve 109, a controller, and a hot water circulation pipeline 1010, where:

[0024] The water tank temperature sensor 107 is arranged in the middle of the water tank 101 for real-time detection of the water temperature in the water tank.

[0025] The electromagnetic three-way valve 109 is arranged on the hot water pipeline connecting the water outlet of the water tank;

[0026] One end of the hot water circulation pipe 1010 is connected to the shell side water inlet end of the shell-to-shell heat exchanger 103, and the other end is connected to the electromagnetic three-way valve 109;

[0027] The outlet water temperature sensor 108 is disposed on the hot water pipe and located at the water inlet end of the electromagnetic three-way valve 109, and is used to detect the outlet water temperature in real time.

[0028] The water tank temperature sensor 107, the water outlet temperature sensor 108, the electromagnetic three-way valve 109 and the heat pump unit 104 are all electrically connected to the controller (not shown in the figure). The controller of this embodiment can adopt a PLC controller or a single-chip microcomputer or other types of controllers.

[0029] According to the multifunctional water tank system based on the heat pump unit, the control method of this embodiment is as follows: when the water tank temperature sensor detects that the water temperature in the water tank is lower than the set water tank temperature, the controller controls the heat pump unit to turn on, and the shell and tube heat exchanger heats the water temperature in the water tank to the set temperature to meet the floor heating requirements.

[0030] When the user uses hot water, the cold water first passes through the heat exchange coil, and the hot water in the water tank preheats the cold water to warm water. When the water tank temperature sensor detects that the water temperature of the water tank is ≥ the set water temperature of the water tank, the heat pump unit is shut down, and the water in the water tank heats the warm water in the shell and tube heat exchanger. The heated water flows to the outlet water temperature sensor. If the water temperature is ≥ the set outlet water temperature, it is directly supplied to the user. If the water temperature is < the set outlet water temperature, the controller controls the electromagnetic three-way valve to switch the passage, and water is introduced into the shell and tube heat exchanger from the hot water circulation pipe. At the same time, the heat pump unit is controlled to start, and the water is heated to the set outlet water temperature by the heat pump unit and then supplied to the user.

[0031] Embodiment 3

[0032] On the basis of the third embodiment, this embodiment further provides a hot water circulation pump 1011 on the hot water circulation pipe 1010 as a power for forced circulation heating. The hot water circulation pump 1011 is linked with the electromagnetic three-way valve 109 for control, that is, when the outlet water temperature is less than the set outlet water temperature, the electromagnetic three-way valve switches to the hot water circulation pipe, and the hot water circulation pump starts at the same time, forcing hot water circulation heating until the outlet water temperature meets the set outlet water temperature.

[0033] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A multifunctional water tank system based on a heat pump unit, characterized in that: Including water tank, heat exchange coil, shell and tube heat exchanger, heat pump unit, floor heating, circulating water pump, including: The heat exchange coil and the shell-and-tube heat exchanger are fixedly installed at the bottom of the water tank and the middle and upper part of the water tank respectively; The water inlet end of the heat exchange coil is connected to the water inlet of the water tank, and the water outlet end thereof is connected to the shell side water inlet end of the shell-and-tube heat exchanger; the shell side water outlet end of the shell-and-tube heat exchanger is connected to the water outlet of the water tank; The two ends of the tube-type heat exchanger are respectively connected to the refrigerant inlet and the refrigerant outlet of the water tank, and are connected to the heat pump unit through the insulation pipe; The water tank, circulating water pump and floor heating are connected to form a closed loop through an insulation pipe; It also includes a water temperature control system, which includes a water tank temperature sensor, a water outlet temperature sensor, an electromagnetic three-way valve and a controller, and a hot water circulation pipeline, wherein: The water tank temperature sensing head is arranged in the middle of the water tank; The electromagnetic three-way valve is arranged on the hot water pipe connected to the water outlet of the water tank; One end of the hot water circulation pipe is connected to the shell side water inlet end of the shell-to-shell heat exchanger, and the other end is connected to the electromagnetic three-way valve; The water outlet temperature sensor is arranged on the hot water pipe and is located at the water inlet end of the electromagnetic three-way valve; The water tank temperature sensor, the water outlet temperature sensor, the electromagnetic three-way valve and the heat pump unit are all connected to the controller via electrical signals.

2. The multifunctional water tank system based on a heat pump unit according to claim 1, wherein: The hot water circulation pipeline is also provided with a hot water circulation pump, and the hot water circulation pump is linked with the electromagnetic three-way valve for control.

3. The control method of the multi-functional water tank system based on a heat pump unit according to claim 1 or 2, characterized in that: The control method is as follows: When the water tank temperature sensor detects that the water temperature in the water tank is lower than the set water temperature in the water tank, the controller controls the heat pump unit to start, and the shell-and-tube heat exchanger heats the water temperature in the water tank to the set temperature to meet the floor heating demand; When the user uses hot water, the cold water first passes through the heat exchange coil, and the hot water in the water tank preheats the cold water to warm water. When the water tank temperature sensor detects that the water temperature of the water tank is ≥ the set water temperature of the water tank, the heat pump unit is shut down, and the water in the water tank heats the warm water in the shell and tube heat exchanger. The heated water flows to the outlet water temperature sensor. If the water temperature is ≥ the set outlet water temperature, it is directly supplied to the user. If the water temperature is < the set outlet water temperature, the controller controls the electromagnetic three-way valve to switch the passage, and water is introduced into the shell and tube heat exchanger from the hot water circulation pipe. At the same time, the heat pump unit is controlled to start, and the water is heated to the set outlet water temperature by the heat pump unit and then supplied to the user.

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