Carbon dioxide heat pump water heater and water tank thereof

Abstract

The water tank of the carbon dioxide heat pump water heater comprises a first water tank body and a second water tank body, the bottom of the first water tank body is communicated with the top of the second water tank body through a flow limiting channel, and the first water tank body is provided with a first connector and a hot water outlet. The first connector is suitable for communicating with a water outlet of the heat pump unit through a pipeline, and the second water tank is provided with a second connector suitable for communicating with a water inlet of the heat pump unit through a pipeline. Due to the fact that the first water tank and the second water tank are communicated through the flow limiting channel, water in the first water tank can only flow into the second water tank slowly, hot water in the first water tank can be kept in a high-temperature state as long as possible, meanwhile, water in the second water tank can have low temperature, and the influence on the efficiency of the heat pump is small. Tap water can enter the second water tank to press out hot water in the first water tank, so that hot water can be used at any time, and the carbon dioxide heat pump water heater has the advantages of a circulating type hot water system and a directly-heated type hot water system.

Description

Technical Field

[0001] The utility model relates to the technical field of water heaters, in particular to a carbon dioxide heat pump water heater and a water tank thereof. Background Art

[0002] Carbon dioxide heat pump water heaters use CO2 as refrigerant. CO2 has a GWP value of only 1, is a natural and environmentally friendly refrigerant, has a large volumetric cooling capacity, and still has a good performance coefficient at low temperatures. However, carbon dioxide heat pump water heaters also have disadvantages: ① The system operating pressure is high, which can reach 100Bar, which requires high system strength and high cost; ② Carbon dioxide heat pumps belong to transcritical cycles and large slip temperature circulation systems. The inlet water temperature has a great influence on the performance coefficient. The lower the inlet water temperature, the higher the efficiency.

[0003] There are two types of existing carbon dioxide heat pump hot water systems, one is a circulation type and the other is a direct heating type.

[0004] like Figure 1 The figure shows a circulating carbon dioxide heat pump hot water system. During use, water circulates continuously between the heat pump and the water tank through the circulating pump and the supporting pipelines, so that the water in the water tank reaches the set temperature. The advantage of this circulating carbon dioxide heat pump hot water system is that it can heat the water in the water tank in a circulating manner; the disadvantage is that as the water temperature in the water tank increases, the temperature of the water entering the heat pump from the water tank will also increase, and the increase in the water temperature entering the heat pump will affect the efficiency of the heat pump.

[0005] like Figure 2 The figure shows a direct-heating carbon dioxide heat pump hot water system. During use, tap water enters the heat pump from the heat pump inlet pipe, and the tap water is heated by the heat pump to become hot water at about 90°C and enters the water tank. For the direct-heating carbon dioxide heat pump hot water system, the advantages are: since the water supplied to the heat pump is always low-temperature self-heated water, and for the heat pump, the lower the inlet water temperature, the higher the efficiency; the disadvantages are: the waiting time for hot water is long, and the water experience is not good.

[0006] Therefore, it is very necessary to design a new carbon dioxide heat pump water heater to have the advantages of both a circulating carbon dioxide heat pump water heating system and a direct-heating carbon dioxide heat pump water heating system. Utility Model Content

[0007] Therefore, the technical problem to be solved by the utility model is that the heat pump efficiency of the circulating carbon dioxide heat pump hot water system is low, the waiting time for hot water in the direct-heating carbon dioxide heat pump hot water system is long, and the water use experience is not good, thereby providing a carbon dioxide heat pump water heater.

[0008] In order to solve the above technical problems, the technical solution of the utility model is as follows:

[0009] A water tank for a carbon dioxide heat pump water heater, the water tank comprising a first water tank and a second water tank, the bottom of the first water tank being connected to the top of the second water tank via a flow limiting channel, the first water tank being provided with a first interface and a hot water outlet, the first interface being suitable for connecting to the hot water outlet of a heat pump unit via a pipeline, the second water tank being provided with a second interface being suitable for connecting to a water inlet of the heat pump unit via a pipeline.

[0010] The water tank of the carbon dioxide heat pump water heater provided by the utility model is connected with the second water tank through the flow limiting channel, so that the water in the first water tank can only flow slowly into the second water tank, so that the hot water in the first water tank does not flow into the second water tank quickly, and the water in the first water tank and the second water tank quickly tends to the same temperature, so that the hot water entering the first water tank from the first interface can be kept in a high temperature state for as long as possible, and the water in the second water tank can have a lower temperature. In this way, when needed, the temperature of the water entering the heat pump unit from the second water tank will be relatively low, and the influence on the efficiency of the heat pump unit will be relatively small. At the same time, since the first water tank and the second water tank are connected, and the second water tank has a second interface for connecting to tap water, when the water heater is in the water outlet state, tap water can enter the second water tank so as to push the hot water in the first water tank out along the hot water outlet, so that hot water is available at any time, and finally the carbon dioxide heat pump water heater has the advantages of both the circulating carbon dioxide heat pump hot water system and the direct-heating carbon dioxide heat pump hot water system.

[0011] A carbon dioxide heat pump water heater, further comprising:

[0012] The aforementioned carbon dioxide heat pump water heater water tank;

[0013] Heat pump units;

[0014] The heat pump water inlet pipe comprises a connecting pipe and an external water pipe; one end of the connecting pipe is connected to the water inlet of the heat pump unit, and the other end is connected to the second interface of the second water tank; the external water pipe is connected to the connecting pipe for supplying tap water into the connecting pipe;

[0015] The heat pump water outlet pipe has one end connected to the water outlet of the heat pump unit and the other end connected to the first interface of the first water tank.

[0016] The technical solution of the utility model has the following advantages:

[0017] The carbon dioxide heat pump water heater provided by the utility model has all the advantages of the water tank of the carbon dioxide heat pump water heater mentioned above. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a structural schematic diagram of an existing circulating carbon dioxide heat pump hot water system;

[0020] Figure 2 It is a structural schematic diagram of an existing direct-heating carbon dioxide heat pump hot water system;

[0021] Figure 3 It is a schematic diagram of the structure of a carbon dioxide heat pump water heater in an embodiment of the utility model.

[0022] Description of reference numerals:

[0023] 1. Heat pump unit; 11. Compressor; 12. Four-way valve; 13. Condenser; 14. Throttle valve; 15. Evaporator; 2. Water tank; 21. First water tank; 211. First interface; 212. Hot water outlet; 213. Return water outlet; 22. Flow limiting channel; 23. Second water tank; 231. Second interface; 3. Heat pump water inlet pipe; 31. Connecting pipe; 311. Heat pump section; 3111. Circulating water pump; 312. Second water tank section; 3121. Control valve; 32. External water pipe; 4. Heat pump water outlet pipe; 5. Hot water pipeline; 6. Zero cooling water pipeline; 61. Zero cooling water pump; 7. Water-using equipment; 81. First temperature sensor; 82. Second temperature sensor. DETAILED DESCRIPTION

[0024] The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0025] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0026] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0028] like Figure 3 As shown, the utility model provides a carbon dioxide heat pump water heater, including a heat pump unit 1, a water tank 2, a first temperature sensor 81, a second temperature sensor 82, a circulating water pump 3111, a zero cooling water pump 61, a controller (not shown) and various connecting pipelines.

[0029] The heat pump unit 1 comprises a compressor 11, a four-way valve 12, a condenser 13, a throttle valve 14, and an evaporator 15. Since the heating of the heat pump unit 1 is a mature technology, it will not be described in detail here.

[0030] The water tank 2 includes a first water tank 21 and a second water tank 23. The volume of the first water tank 21 is greater than that of the second water tank 23, so that it is convenient to store more hot water. The bottom of the first water tank 21 is connected to the top of the second water tank 23 through a flow limiting channel 22. The diameter of the flow limiting channel 22 is 20 mm to 200 mm. The first water tank 21 is provided with a first interface 211 and a hot water outlet 212. The first interface 211 is connected to the water outlet of the heat pump unit 1 through a pipeline. The position of the hot water outlet 212 is not lower than the position of the first interface 211, so that the water in the second water tank 23 can push out the water in the first water tank 21. The second water tank 23 is provided with a second interface 231, and the second interface 231 is connected to the water inlet of the heat pump unit 1.

[0031] In this embodiment, the first water tank 21 and the second water tank 23 are integrally formed.

[0032] In other embodiments, the first water tank 21 and the second water tank 23 are formed independently and then assembled and connected together.

[0033] The first temperature sensor 81 is installed on the first water tank 21 to detect the water temperature in the first water tank 21 .

[0034] The second temperature sensor 82 is installed on the second water tank 23 to detect the water temperature in the second water tank 23 .

[0035] The connecting pipelines mainly include a heat pump water inlet pipe 3 , a heat pump water outlet pipe 4 , a hot water pipeline 5 and a zero cold water pipeline 6 .

[0036] The heat pump water inlet pipe 3 includes a connecting pipe 31 and an external water pipe 32. Tap water is supplied to the connecting pipe through the external water pipe 32. Figure 3 From the perspective of FIG. 1 , the portion of the connecting pipe 31 located on the left side of the external water pipe 32 is defined as the heat pump section 311, and the portion located on the right side of the external water pipe 32 is defined as the second water tank section 312. A normally closed control valve 3121 is installed on the second water tank section 312 to control the on and off of the second water tank section 312. A circulating water pump 3111 is installed on the heat pump section 311 to pump tap water into the heat pump unit 1 or pump water in the second water tank 23 into the heat pump unit 1.

[0037] One end of the heat pump water outlet pipe 4 is connected to the water outlet of the heat pump unit 1 , and the other end is connected to the first interface 211 of the first water tank 21 .

[0038] One end of the hot water pipeline 5 is connected to the hot water outlet 212 of the first water tank 21, and the other end is connected to the water-using equipment 7 (such as a shower).

[0039] One end of the zero cold water pipeline 6 is connected to the hot water pipeline 5, and the other end is connected to the return water port 213 opened on the first water tank 21. A zero cold water pump 61 is installed on the zero cold water pipeline 6, so that when the water temperature in the hot water pipeline 5 does not meet the preset value, the water in the hot water pipeline 5 is pumped back to the water tank 2.

[0040] The working process of the utility model carbon dioxide heat pump water heater is introduced below:

[0041] During the initial water filling, cold tap water is stored in the first water tank 21;

[0042] Start the circulating water pump 3111 and the heat pump unit 1, enter the heating state, tap water enters the heat pump unit 1 from the external water pipe 32 along the heat pump section 311, and after the tap water is heated by the heat pump unit 1, high-temperature hot water of 70°C to 90°C is output, and the high-temperature hot water is stored in the first water tank 21; after a period of heating, the water volume in the first water tank 21 gradually increases, the water temperature will gradually rise, and as the water in the first water tank 21 flows into the second water tank 23, the water temperature in the second water tank 23 will also gradually rise; when the water temperature in the second water tank 23 reaches the second preset value, the second temperature sensor 82 sends a shutdown signal, and the controller receives the shutdown signal and controls the heat pump unit 1 to shut down;

[0043] When the user uses hot water (also referred to as the water outlet state), the controller controls the control valve 3121 on the second water tank section 312 to open, and tap water enters from the external water pipe 32 and enters the second water tank 23 along the second water tank section 312. The pressure in the second water tank 23 increases, and the hot water in the first water tank 21 is pressed out from the hot water outlet 212 at the top of the first water tank 21.

[0044] As the tap water enters the second water tank 23, the water temperature in the second water tank 23 gradually decreases. At the same time, as the water in the second water tank 23 enters the first water tank 21, the water temperature in the first water tank 21 also gradually decreases. When the water temperature in the first water tank 21 drops to a first preset value, the first temperature sensor 81 sends a start signal, and the controller receives the start signal and controls the heat pump unit 1 and the circulating water pump 3111 to start and enter the heating state again. When the water temperature in the second water tank 23 rises to a second preset value, the controller controls the heat pump unit 1 to stop.

[0045] In the insulation state, when the water temperature in the first water tank 21 is lower than the preset value, the controller controls the heat pump unit 1 and the circulating water pump 3111 to start, the water heater enters the heating state again, and controls the control valve 3121 on the second water tank section 312 to open; the water in the second water tank 23 enters the heat pump unit 1 along the second water tank section 312 and the heat pump section 311 in turn, and is heated by the heat pump unit 1 until the water temperature in the second water tank 23 rises to the second preset value, and the controller controls the heat pump unit 1 to shut down.

[0046] In the present invention, since the first water tank 21 and the second water tank 23 are connected through the flow limiting channel 22, the water in the first water tank 21 can only flow slowly into the second water tank 23, so that the hot water in the first water tank 21 does not flow quickly into the second water tank 23, and the water in the first water tank 21 and the second water tank 23 tend to be at the same temperature, so that the hot water entering the first water tank 21 from the first interface 211 can be kept at a high temperature for as long as possible, and the water in the second water tank 23 can have a lower temperature. In this way, when necessary, the water entering the heat pump from the second water tank 23 The temperature of the water in unit 1 will be relatively low, and the effect on the efficiency of the heat pump unit 1 will be relatively small. At the same time, since the first water tank 21 and the second water tank 23 are connected, and the second water tank 23 has a second interface 231 for connecting to tap water, when the water heater is in the water outlet state, tap water can enter the second water tank 23 to push the hot water in the first water tank 21 out along the hot water outlet 212, so that hot water is available at any time, and finally the carbon dioxide heat pump water heater has the advantages of both a circulating carbon dioxide heat pump hot water system and a direct-heating carbon dioxide heat pump hot water system.

[0047] In addition, since a second temperature sensor 82 is provided to detect the water temperature in the second water tank 23, when the water temperature in the second water tank 23 rises to reach a second preset value, the heat pump unit 1 shuts down. In this way, it can be ensured that the water temperature in the second water tank 23 will not be too high, thereby reducing the impact on the efficiency of the heat pump unit 1 when returning water from the second water tank 23 to the heat pump unit 1 and reducing the energy consumption of the heat pump unit 1.

[0048] Furthermore, since a first temperature sensor 81 is provided to detect the water temperature in the first water tank 21, when the water temperature in the first water tank 21 drops to reach the first preset temperature value, the water in the second water tank 23 flows back into the heat pump unit 1 through the second water tank section 312 and the heat pump section 311 in turn. In this way, it can be ensured that the water in the first water tank 21 can be kept at a suitable temperature for a long time, thereby improving the user experience.

[0049] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention of the utility model.

Claims

1. A carbon dioxide heat pump water heater water tank, characterized in that: The water tank (2) comprises a first water tank (21) and a second water tank (23); the bottom of the first water tank (21) is connected to the top of the second water tank (23) via a flow limiting channel (22); the first water tank (21) is provided with a first interface (211) and a hot water outlet (212); the first interface (211) is suitable for connecting to a water outlet of the heat pump unit (1); the second water tank (23) is provided with a second interface (231) is suitable for connecting to a water inlet of the heat pump unit (1).

2. The carbon dioxide heat pump water heater water tank according to claim 1, characterized in that: The diameter of the flow limiting channel (22) is 20 mm to 200 mm.

3. The carbon dioxide heat pump water heater water tank according to claim 1, characterized in that: The volume of the first water tank (21) is greater than the volume of the second water tank (23).

4. The carbon dioxide heat pump water heater water tank according to any one of claims 1 to 3, characterized in that: The position of the hot water outlet (212) is no lower than the position of the first interface (211).

5. The carbon dioxide heat pump water heater water tank according to any one of claims 1 to 3, characterized in that: The first water tank (21) and the second water tank (23) are integrally formed.

6. A carbon dioxide heat pump water heater, characterized in that: Also includes: The carbon dioxide heat pump water heater water tank according to any one of claims 1 to 5; Heat pump unit (1); The heat pump water inlet pipe (3) comprises a connecting pipe (31) and an external water pipe (32); one end of the connecting pipe (31) is in communication with the water inlet of the heat pump unit (1), and the other end is in communication with the second interface (231) of the second water tank (23); the external water pipe (32) is connected to the connecting pipe (31) and is used to supply tap water into the connecting pipe (31); A heat pump water outlet pipe (4) has one end connected to the water outlet of the heat pump unit (1) and the other end connected to the first interface (211) of the first water tank (21).

7. The carbon dioxide heat pump water heater according to claim 6, characterized in that: It also includes a controller and a second temperature sensor (82) which are electrically connected, wherein the second temperature sensor (82) is used to detect the water temperature in the second water tank (23); the controller receives a shutdown signal sent by the second temperature sensor (82), and controls the heat pump unit (1) to shut down according to the shutdown signal.

8. The carbon dioxide heat pump water heater according to claim 7, characterized in that: It also includes a first temperature sensor (81), which is used to detect the water temperature in the first water tank (21); the controller receives a start signal sent by the first temperature sensor (81), and controls the start of the heat pump unit (1) according to the start signal.

9. The carbon dioxide heat pump water heater according to claim 7 or 8, characterized in that: It also includes a control valve (3121) and a circulating water pump (3111) both of which are installed on the connecting pipe (31); the connecting pipe (31) includes a second water tank section (312) located between the external water pipe (32) and the second interface (231); the control valve (3121) is used to control the on and off of the second water tank section (312).

10. The carbon dioxide heat pump water heater according to any one of claims 6 to 8, characterized in that: It also includes a hot water pipeline (5) and a zero cold water pipeline (6); one end of the hot water pipeline (5) is connected to the hot water outlet (212) of the first water tank (21), and the other end is suitable for connecting to a water-using device (7); one end of the zero cold water pipeline (6) is connected to the hot water pipeline (5), and the other end is connected to a return water port (213) provided on the first water tank (21); and a zero cold water pump (61) is installed on the zero cold water pipeline (6).

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