Hot water system control method

Abstract

The present invention relates to the technical field of heat pump heating, and particularly relates to a control method for a hot water system. This method is applied to a hot water system, which includes a heat storage unit and a heating unit. The heat storage unit includes a first liquid storage module, a second liquid storage module, and a third liquid storage module that are connected in series in sequence. The first liquid storage module and the third liquid storage module are respectively arranged at the head end and the tail end of the heat storage unit. The heating unit includes a heat pump main unit and a heating water tank, and the heating water tank is connected to the first liquid storage module. This method includes: obtaining the temperature of the liquid in the heating water tank and the temperatures of the liquid storage modules in the heat storage unit, comparing the temperatures of the liquid storage modules with the set temperature parameters, and then controlling the operating frequency range of the heat pump main unit according to the comparison results. The control method of the hot water system in this application divides the heat storage unit into three demand areas, judges the current user demand through the temperatures of the liquid storage modules, and adjusts the frequency of the variable-frequency heat pump main unit according to the user demand, achieving high efficiency, energy conservation, and environmental protection.

Description

Technical Field

[0001] The present invention relates to the technical field of heat pump heating, and particularly relates to a control method for a hot water system. Background Art

[0002] In a traditional variable-frequency heat pump and an open-type water tank hot water system, a variable-frequency heat pump water heater is combined with an open-type water tank to achieve functions of circulating heating and dynamic water replenishment. The main unit performs variable-frequency adjustment according to the energy demand of the system. That is, the operating frequency of the main unit is controlled according to the difference between the target water temperature and the water tank temperature. The greater the difference, the higher the operating frequency. The water replenishment logic of the open-type water tank: The water tank is divided into a high water level constant temperature area, a middle water level temperature control water replenishment area, and a low water level forced water replenishment area according to the water level height. For example, in the high water level constant temperature area, the unit performs temperature control according to the set temperature; in the middle water level temperature control water replenishment area, the unit performs dynamic water replenishment according to the deviation from the set temperature; in the forced water replenishment area, the unit gives priority to water replenishment. In this system, the water temperature in the water tank rises slowly, which affects the customer experience and at the same time the main unit runs frequently, resulting in low comprehensive energy efficiency and poor variable-frequency energy-saving benefits.

[0003] A traditional closed-type pressure-bearing system is connected to a fixed-frequency heat pump main unit, which can only be turned on and off according to demand, cannot perform frequency control, cannot adapt to the needs of the user's water use end, and has poor energy-saving effects. Summary of the Invention

[0004] The present invention provides a control method for a hot water system, aiming to solve the problem that the heat pump main unit of the existing hot water system cannot perform frequency control, resulting in low comprehensive energy efficiency and poor energy-saving benefits.

[0005] In a first aspect, an embodiment of the present invention provides a control method for a hot water system, which is applied to a hot water system. The hot water system includes: a heat storage unit, including a first liquid storage module, a second liquid storage module, and a third liquid storage module connected in series and communicated in sequence. The first liquid storage module and the third liquid storage module are respectively arranged at the head end and the tail end of the heat storage unit; and a heating unit, including a heat pump main unit and a heating water tank. The heat pump main unit can convey the heated liquid to the heating water tank, and the heating water tank is communicated with the first liquid storage module so that at least part of the liquid in the heating water tank can enter the first liquid storage module. The control method for the hot water system includes: obtaining the temperature T of the liquid in the heating water tank a , the temperature T of the liquid in the first liquid storage module b , the temperature T of the liquid in the second liquid storage module c , the temperature T of the liquid in the third liquid storage module d ; when T c > t 1 , keep the heat pump main unit in a non-start state; when t 2 < T c ≤ t 1When, control the heat pump main unit to operate within the first frequency range; when T c ≤t 2 and T b >t 0 When, control the heat pump main unit to operate within the second frequency range; when T b <t 0 When, control the heat pump main unit to operate within the third frequency range, where t 0 is the target temperature, t 1 is the first preset temperature, t 2 is the second preset temperature, t 0 >t 1 >t 2 , the third frequency range is higher than the second frequency range, and the second frequency range is higher than the first frequency range.

[0006] According to the foregoing embodiments of the first aspect of the present invention, the hot water system control method further includes: when the heat pump main unit operates within the first frequency range until T d >t 0 , keep the heat pump main unit in a non-start state; when the heat pump main unit operates within the second frequency range until T c >t 2 , control the heat pump main unit to operate within the first frequency range; when the heat pump main unit operates within the third frequency range until T b >t 0 and T a >t 0 When, control the heat pump main unit to operate within the second frequency range.

[0007] According to any of the foregoing embodiments of the first aspect of the present invention, the heating water tank is provided with a heating component, and the heating component is used to heat the liquid in the heating water tank.

[0008] According to any of the foregoing embodiments of the first aspect of the present invention, when T b <t 0 and T a >t 0 When, control the heat pump main unit to operate at the third frequency; when T b <t 0 and T a <t 0 When, control the heating component to turn on, and at the same time control the heat pump main unit to operate at the third frequency; when T b >t 0 and T a >t 0 When, control the heating component to turn off, and at the same time control the heat pump main unit to operate at the second frequency; when T c >t2 Subsequently, control the heat pump main unit to operate at the first frequency; when T d > t 0 , keep the heat pump main unit in a non-start state.

[0009] According to any of the foregoing embodiments of the first aspect of the present invention, the hot water system further includes: a make-up water pipeline for supplying water to the heating unit and / or the heat storage unit; and a control component for controlling whether the make-up water pipeline supplies liquid to the heating unit.

[0010] According to any of the foregoing embodiments of the first aspect of the present invention, when T b < t 0 and T a < t 0 , control the control component to stop the make-up water pipeline from supplying liquid to the heating unit until Ta > t0, and then control the control component to supply liquid to the heating unit through the make-up water pipeline.

[0011] According to any of the foregoing embodiments of the first aspect of the present invention, the control component includes a power water pump and a solenoid valve. The power water pump is arranged between the solenoid valve and the heating unit; when T b < t 0 and T a < t 0 , control the heating component to turn on, and at the same time control the heat pump main unit to operate at the third frequency, control the power water pump to turn off, and adjust the solenoid valve to the minimum safety step number so that the make-up water pipeline supplies water to the heat storage unit; until Ta > t0, control the power water pump and the solenoid valve to open so that the make-up water pipeline gradually replenishes water to the heating unit again.

[0012] According to any of the foregoing embodiments of the first aspect of the present invention, the heating unit further includes a first connection pipeline and a second connection pipeline connected between the heat pump main unit and the heating water tank. The liquid in the heat pump main unit can enter the heating water tank through the first connection pipeline, and the control component is arranged on the second connection pipeline; the control component has a first state and a second state; in the first state of the control component, the liquid in the make-up water pipeline enters the heat pump main unit after being mixed with the liquid from the heating water tank in the second connection pipeline; in the second state of the control component, the liquid in the make-up water pipeline enters the heat storage unit; when T b < t 0 and T a < t 0When Ta ≤ t0, control the heating component to turn on, and at the same time control the heat pump host to operate at the third frequency, and control the control component to be in the second state, so that the water supply pipeline supplies water to the heat storage unit; until Ta > t0, control the control component to be in the first state, so that the water supply pipeline gradually supplies water to the heating unit again.

[0013] According to any one of the foregoing embodiments of the first aspect of the present invention, the control component includes: an electric three-way valve, a first end of the electric three-way valve is connected to the heat pump host, a second end of the electric three-way valve is connected to the heating water tank, and a third end of the electric three-way valve is connected to the water supply pipeline; a circulation water pump is arranged between the first end of the electric three-way valve and the heat pump host; and a first one-way valve is arranged between the second end of the electric three-way valve and the heating water tank, and the first one-way valve is used to control the one-way flow of liquid from the heating water tank to the electric three-way valve.

[0014] According to any one of the foregoing embodiments of the first aspect of the present invention, the hot water system control method further includes: obtaining the average temperature T of the liquid in the heating water tank within the first preset time period a1 and the average temperature T of the liquid in the heat storage unit within the first preset time period c1 , and controlling the valve opening of the electric three-way valve according to T a1 , T c1 and the target temperature t 0 ; when the temperature t of the hot water storage tank 1 <T c1 <t 0 , the electric three-way valve is at the minimum safe step; when t 2 <T c1 ≤t 1 , control the electric three-way valve to maintain a fixed initial opening for a period of time e and then start the circulation water pump; detect the temperature of the heating water tank at the second preset time frequency, when T a1 >t 0 , the electric three-way valve increases by N steps, where N is a positive integer; when T a1 =t 0 , the electric three-way valve maintains the current number of steps; when T a1 <t 0 , if T b >t 0 , control the electric three-way valve to gradually decrease by N steps; if T b ≤t 0 , control the electric three-way valve to decrease by N + k steps until it is closed to the minimum safe range of the electric three-way valve; until it is detected that T a1 -t 0 ≥0, reopen the electric three-way valve, where k is a positive integer; when T d >t0 When the circulating water pump is controlled to be closed, the electric three-way valve is controlled to be at the minimum safe number of steps.

[0015] According to any of the foregoing embodiments of the first aspect of the present invention, the hot water system further includes a water supply pipeline. The first liquid storage module is communicated with the heating water tank through a third connection pipeline. The water supply pipeline is communicated with the third connection pipeline, and the water supply pipeline is communicated with the outside; when T c > t 1 When, the heat storage unit supplies liquid to the water supply pipeline; when t 2 < T c ≤ t 1 When, the heating unit supplies liquid to the water supply pipeline; when T c ≤ t 2 And T b > t 0 When, the heating unit supplies liquid to the water supply pipeline; when T b < t 0 And T a > t 0 When, the heating unit supplies liquid to the water supply pipeline; when T b < t 0 And T a < t 0 When, in the state that the heating component is turned on and the heat pump host operates at the third frequency, the heat storage unit supplies liquid to the water supply pipeline; when T b > t 0 And T a > t 0 When, the heating unit supplies liquid to the water supply pipeline.

[0016] According to any of the foregoing embodiments of the first aspect of the present invention, the hot water system further includes a return water pipeline. The return water pipeline is communicated with the make-up water pipeline, and the return water pipeline can be used to supply water to the heating unit and / or the heat storage unit.

[0017] According to any of the foregoing embodiments of the first aspect of the present invention, the steps of obtaining the temperature T a of the liquid in the heating water tank, the temperature T b of the liquid in the first liquid storage module, the temperature T c of the liquid in the second liquid storage module, and the temperature T d of the liquid in the third liquid storage module include: obtaining the temperature T a of the liquid in the heating water tank through a first temperature sensor arranged at the upper part of the heating water tank, and obtaining the temperature T b of the liquid in the first liquid storage module through a second temperature sensor arranged at the upper part of the first liquid storage module., the temperature T of the liquid in the second liquid storage module is obtained by a third temperature sensor disposed in the middle of the second liquid storage module c , a fourth temperature sensor is disposed at the lower part of the third liquid storage module to obtain the temperature T of the liquid in the third liquid storage module d .

[0018] According to any of the foregoing embodiments of the first aspect of the present invention, the first liquid storage module is a first hot water storage tank, the second liquid storage module includes at least one second hot water storage tank connected in series, and the third liquid storage module is a third hot water storage tank, wherein, T c is the temperature of the liquid in the second hot water storage tank located in the middle of the heat storage unit.

[0019] According to the hot water system control method of the embodiment of the present invention, by dividing the heat storage unit into three demand regions, judging the current user demand through the temperature of each liquid storage module, and adjusting the frequency of the variable frequency heat pump host according to the user demand, the control frequency is used to control the closed pressure hot water system, so as to realize a more energy-saving closed pressure hot water system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. 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 be obtained based on the structures shown in these drawings.

[0021] Figure 1 is a schematic structural diagram of a hot water system according to an embodiment of the present invention;

[0022] Figure 2 is a schematic structural diagram of a hot water system according to another embodiment of the present invention;

[0023] Figure 3 is a schematic structural diagram of a heat storage unit according to an embodiment of the present invention.

[0024] Explanation of the reference numerals in the drawings:

[0025] 100 - Heating unit; 110 - Heat pump main unit; 120 - Heating water tank; 121 - First temperature sensor; 122 - Heating component; 130 - First connection pipeline; 140 - Second connection pipeline; 150 - Control component; 151 - Electric three - way valve; 152 - Circulation water pump; 153 - First check valve; 154 - Power water pump; 155 - Solenoid valve; 200 - Heat storage unit; 210 - First liquid storage module; 211 - Second temperature sensor; 212 - First heat storage water tank; 220 - Second liquid storage module; 221 - Third temperature sensor; 222 - Second heat storage water tank; 230 - Third liquid storage module; 231 - Fourth temperature sensor; 232 - Third heat storage water tank; 300 - Make - up water pipeline; 400 - Third connection pipeline; 500 - Water supply pipeline; 600 - Return water pipeline; 610 - Confluence part.

[0026] The realization, functional features and advantages of the purpose of the present invention will be further described with reference to the embodiments and the accompanying drawings. Detailed implementation manners

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part 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 shall fall within the protection scope of the present invention.

[0028] It should be noted that all the directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative position relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0029] In addition, the descriptions involving "first", "second", etc. in the present invention are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0030] The present invention provides a control method for a hot water system, which is applied to a hot water system. The hot water system includes a heat storage unit and a heating unit. The heat storage unit includes a first liquid storage module, a second liquid storage module, and a third liquid storage module connected in series and communicated in sequence. The first liquid storage module and the third liquid storage module are respectively arranged at the head end and the tail end of the heat storage unit. The heating unit includes a heat pump main unit and a heating water tank. The heat pump main unit can transport the heated liquid to the heating water tank, and the heating water tank is communicated with the first liquid storage module so that at least part of the liquid in the heating water tank can enter the first liquid storage module. The hot water system control method includes: obtaining the temperature T of the liquid in the heating water tank a , the temperature T of the liquid in the first liquid storage module b , the temperature T of the liquid in the second liquid storage module c , the temperature T of the liquid in the third liquid storage module d ; when T c >t 1 , keep the heat pump main unit in the non-start state; when t 2 <T c ≤t 1 , control the heat pump main unit to operate in the first frequency range; when T c ≤t 2 and T b >t 0 , control the heat pump main unit to operate in the second frequency range; when T b <t 0 , control the heat pump main unit to operate in the third frequency range, where t 0 is the target temperature, t 1 is the first preset temperature, t 2 is the second preset temperature, t 0 >t 1 >t 2 , the third frequency range is higher than the second frequency range, and the second frequency range is higher than the first frequency range. According to the hot water system control method of the present application, by obtaining the temperatures of the liquid storage modules in the liquid storage unit to control the operating frequency range of the heat pump main unit, while reducing the frequent start and stop of the heat pump main unit, it can avoid the problems of slow water temperature rise and low system operation energy efficiency, and achieve environmental protection and energy saving.

[0031] Refer to Figures 1 to 3 , the hot water system control method of the present application is applied to a hot water system Figure 1 and Figure 2An embodiment of a hot water system is shown respectively. Specifically, the hot water system includes: a heat storage unit 200 and a heating unit 100. Among them, the heat storage unit 200 includes a first liquid storage module 210, a second liquid storage module 220, and a third liquid storage module 230 that are connected in series in sequence. The first liquid storage module 210 and the third liquid storage module 230 are respectively arranged at the head end and the tail end of the heat storage unit 200. The heating unit 100 includes a heat pump main unit 110 and a heating water tank 120. The heat pump main unit 110 can transport the heated liquid to the heating water tank 120, and the heating water tank 120 is connected to the first liquid storage module 210 so that at least part of the liquid in the heating water tank 120 can enter the first liquid storage module 210.

[0032] Furthermore, the hot water system control method includes:

[0033] Obtain the temperatures of the first liquid storage module 210, the second liquid storage module 220, and the third liquid storage module 230 in the heat storage unit 200 to control the heating unit 100.

[0034] Specifically, obtain the temperature T of the liquid in the heating water tank 120 a , the temperature T of the liquid in the first liquid storage module 210 b , the temperature T of the liquid in the second liquid storage module 220 c , the temperature T of the liquid in the third liquid storage module 230 d ; when T c > t 1 , at this time it is the low water demand area, control the hot water system to maintain the constant temperature shutdown stage, and keep the heat pump main unit 110 in the non-start state; when t 2 < T c ≤ t 1 , at this time it is still the low water demand area, but the user's water consumption has increased slightly, control the hot water system to be in the low-frequency heat supplement stage. Specifically, control the heat pump main unit 110 to operate in the first frequency range; when T c ≤ t 2 and T b > t 0 , at this time the user's water consumption demand begins to gradually increase and becomes the medium water demand period, control the heat pump main unit 110 to operate in the second frequency range; when T b < t 0 , the user's water consumption increases rapidly, that is, it is the high water demand period, control the heat pump main unit 110 to operate in the third frequency range, where t 0 is the target temperature, t 1 is the first preset temperature, t 2 is the second preset temperature, t 0 > t 1 > t 2, the third frequency range is higher than the second frequency range, and the second frequency range is higher than the first frequency range. Further, by way of example and not limitation, t 1 , t 2 is an interval control parameter set according to t 0 , t 2 = t 0 - X, t 1 = t 0 - Y, X ∈ (8, 12), Y ∈ (3, 7). Those skilled in the art can flexibly adjust the numerical ranges of the heat pump main unit 110 in the three frequency ranges. By way of example and not limitation, the first frequency is 50 to 80 Hz, the second frequency is 80 to 100 Hz, and the third frequency is 100 to 120 Hz. That is, the hot water system control method of the embodiments of the present application can divide the demand area according to the user's water use demand, adjust the frequency of the variable frequency heat pump main unit, and control the closed-loop pressure-bearing hot water system by controlling the frequency, so as to realize a more energy-saving closed-loop pressure-bearing hot water system.

[0035] Further, the hot water system control method further includes: when the heat pump main unit 110 operates in the first frequency range until T d > t 0 , keep the heat pump main unit 110 in a non-start state; when the heat pump main unit 110 operates in the second frequency range until T c > t 2 , control the heat pump main unit 110 to operate in the first frequency range; when the heat pump main unit 110 operates in the third frequency range until T b > t 0 and T a > t 0 , control the heat pump main unit 110 to operate in the second frequency range.

[0036] In some alternative embodiments, the heating water tank 120 is provided with a heating component 122, and the heating component 122 is used to heat the liquid in the heating water tank 120. Further, according to this embodiment, the hot water system control method further includes: when T b < t 0 and T a > t 0 , control the heat pump main unit 110 to operate at the third frequency; when T b < t 0 and T a < t 0 , control the heating component 122 to turn on, and at the same time control the heat pump main unit 110 to operate at the third frequency; when T b > t 0 and T a > t 0 , control the heating component 122 to turn off, and at the same time control the heat pump main unit 110 to operate at the second frequency; when Tc > t 2 Subsequently, control the heat pump main unit 110 to operate at the first frequency; when T d > t 0 , keep the heat pump main unit 110 in a non-start state. In this application, by setting the heating component 122, when T b < t 0 , jointly heat the liquid through the heat pump main unit 110 and the heating component 122 to achieve rapid temperature rise.

[0037] Furthermore, in some other alternative embodiments, the hot water system further includes: a makeup water pipeline 300 and a control component 150, wherein the makeup water pipeline 300 is used to supply water to the heating unit 100 and / or the heat storage unit 200; the control component 150 is used to control whether the makeup water pipeline 300 supplies liquid to the heating unit 100. Specifically, when T b < t 0 and T a < t 0 , control the makeup water pipeline 300 to stop supplying liquid to the heating unit 100 through the control component 150 until Ta > t0, and then control the makeup water pipeline 300 to supply liquid to the heating unit 100 through the control component 150. When T b < t 0 and T a < t 0 , that is, during the high-demand period of water use, according to this embodiment, control the makeup water pipeline 300 to stop supplying liquid to the heating unit 100, and at the same time, the heat pump main unit 110 and the heating component 122 operate simultaneously, which can quickly heat the liquid, enabling users to use hot water in a short time even during the peak water use period and providing users with a long-term and stable hot water supply.

[0038] Refer to Figure 1 , Figure 1 , which is a schematic structural diagram of a hot water system according to an embodiment of the present invention. In this embodiment, the control component 150 includes a power water pump 154 and a solenoid valve 155, and the power water pump 154 is arranged between the solenoid valve 155 and the heating unit 100. That is, according to this embodiment, the hot water system includes a heating unit 100, a heat storage unit 200, and a makeup water pipeline 300. Among them, the heating unit 100 includes a heat pump main unit 110 and a heating water tank 120, the heat storage unit 200 includes a plurality of sequentially connected and communicated liquid storage modules, one end of the makeup water pipeline 300 is connected to the heating water tank 120 through the solenoid valve 155 and the power water pump 154 in sequence, and the other end of the makeup water pipeline 300 is connected to the liquid storage module at the end of the heat storage unit 200. The heating unit 100 and the heat storage unit 200 are connected by a water pipe, and the water pipe communicates with the user's water outlet end. The hot water system according to this embodiment is also called a circulating closed-pressure system. When T b < t 0 and T a<t 0 When T is less than t, control the heating component 122 to turn on, and at the same time control the heat pump main unit 110 to operate at the third frequency, control the power water pump 154 to turn off, and adjust the solenoid valve 155 to the minimum safety step number, so that the water supply pipe 300 replenishes water for the heat storage unit 200; until T a >t 0 When T is greater than t, control the power water pump 154 and the solenoid valve 155 to open, so that the water supply pipe 300 gradually replenishes water for the heating unit 100 again.

[0039] Refer to Figure 2 , Figure 2 FIG. b <t 0 and T a <t 0 When T is less than t and T is less than t, control the heating component 122 to turn on, and at the same time control the heat pump main unit 110 to operate at the third frequency, control the control component 150 to be in the second state, so that the water supply pipe 300 replenishes water for the heat storage unit 200; until T a >t 0 When T is greater than t, control the control component 150 to be in the first state, so that the water supply pipe 300 gradually replenishes water for the heating unit 100 again.

[0040] For the hot water system according to the embodiment of the present invention, by setting the control component 150 to control the water supply pipe 300 to realize the switching of the system mode. In the first state of the control component 150, the liquid is heated in the heat pump main unit 110 and then enters the heating water tank 120 through the first connection pipe 130. A part of the water in the heating water tank 120 enters the heat storage unit 200, and the water at the other outlet is mixed with the liquid in the water supply pipe 300 in the second connection pipe 140 and then enters the heat pump main unit 110. The system enters the direct heating circulation mode, that is, the liquid is quickly heated through the power circulation and the main circulation together; in the second state of the control component 150, the liquid in the water supply pipe 300 enters the end of the heat storage unit 200 for water replenishment. At this time, only the main circulation of the heating unit 100 is maintained, and the heat pump main unit 110 directly heats the liquid in the heating water tank 120. This mode is energy-saving and environmentally friendly.

[0041] Further, the control component 150 includes: an electric three-way valve 151, a circulating water pump 152, and a first check valve 153. The first end of the electric three-way valve 151 is connected to the heat pump main unit 110, the second end of the electric three-way valve 151 is connected to the heating water tank 120, and the third end of the electric three-way valve 151 is connected to the make-up water pipeline 300. The circulating water pump 152 is arranged between the first end of the electric three-way valve 151 and the heat pump main unit 110. The first check valve 153 is arranged between the second end of the electric three-way valve 151 and the heating water tank 120, and the first check valve 153 is used to control the one-way flow of liquid from the heating water tank 120 to the electric three-way valve 151.

[0042] Specifically, when the control component 150 is in the first state, the valve opening of the electric three-way valve 151 is greater than the first preset value. At this time, the resistance of the heating unit 100 is smaller than that of the heat storage unit 200. After being heated in the heat pump host 110, it returns to the heating water tank 120. Part of the water in the heating water tank 120 enters the heat storage unit 200, and the other part of the water at the outlet is mixed with the water on the make-up side of the power cycle and then enters the host again to achieve direct heating circulation. When the control component 150 is in the second state, the valve opening of the electric three-way valve 151 is less than the second preset value, and the resistance of the heating unit 100 becomes larger, so that the liquid in the make-up water pipeline 300 can enter the end of the heat storage unit 200 for make-up water. At this time, only the main circulation of the heating unit 100 is maintained, and the heat pump host 110 directly heats the water in the heating water tank 120 for internal circulation. When in internal circulation, the customer's water use is only provided by the heating unit 100, and the heating unit 100 does not provide heat for the heat storage unit 200. This mode is the direct heating mode. It can be understood that the first preset value and the second preset value can be flexibly set by those skilled in the art according to the actual connecting pipelines, hydraulic pressure, water pump power, etc. in the hot water system, and will not be listed one by one here. According to the hot water system of this embodiment, the structure is simple and the control is easy. By adjusting the valve opening of the electric three-way valve 151, the system mode can be switched, and rapid heating can be achieved to meet the user's water use requirements. That is, according to this embodiment, the hot water system includes a heating unit 100, a heat storage unit 200, and a make-up water pipeline 300. Among them, the heating unit 100 includes a heat pump host 110 and a heating water tank 120. The heat pump host 110 and the heating water tank 120 are connected through a first connecting pipeline 130 and a second connecting pipeline 140. The liquid in the heat pump host 110 can enter the heating water tank 120 through the first connecting pipeline 130. The second connecting pipeline 140 is provided with a control component 150. The control component 150 includes an electric three-way valve 151, a circulation water pump 152, and a first one-way valve 153. By adjusting the valve opening of the electric three-way valve 151, the working state of the hot water system of this embodiment can be adjusted to the direct heating circulation state or the internal circulation state. The heat storage unit 200 includes a plurality of liquid storage modules connected in series in sequence. One end of the make-up water pipeline 300 is connected to the heating unit 100 through the electric three-way valve 151, and the other end of the make-up water pipeline 300 is connected to the liquid storage module at the end of the heat storage unit 200. The heating unit 100 and the heat storage unit 200 are connected by a water pipe, and the water pipe is connected to the user's water outlet end. The hot water system according to this embodiment is also called a direct heating circulation closed pressure-bearing system.

[0043] Further, for a continuous period of time f 1 The average temperature T of the heating water tank 120 detected within a1 And the target parameter t 0 The difference controls the electric three-way valve 151 within the valve opening adjustment range of the electric three-way valve 151. The control method of the hot water system according to this embodiment further includes: obtaining a first preset time period f1 The average temperature T of the liquid in the internal heating water tank 120 a1 and the first preset time period f 1 The average temperature T of the liquid in the internal heat storage unit 200 c1 , according to T a1 、T c1 and the target temperature t 0 Control the valve opening of the electric three-way valve 151. When the hot water storage tank t 1 <T c1 <t 0 , the electric three-way valve 151 is at the minimum safe step; when t 2 <T c1 ≤t 1 , control the electric three-way valve 151 to maintain a fixed initial opening for a period of time e, and then start the circulation pump 152; detect the temperature of the heating water tank 120 at the frequency of the second preset time f 2 , f 2 ∈(8, 12), when T a1 >t 0 , the electric three-way valve 151 increases by N steps, where N is a positive integer; wait for the next first preset time period to cycle and re-obtain T a1 ; when T a1 =t 0 , the electric three-way valve 151 maintains the current number of steps; when T a1 <t 0 , if T b >t 0 , control the electric three-way valve 151 to gradually decrease by N steps; if T b ≤t 0 , control the electric three-way valve 151 to decrease by N + k steps, where k is a positive integer; until it is closed to the minimum safe range of the electric three-way valve 151; until it is detected that T a1 -t 0 ≥0, reopen the electric three-way valve 151 and enter a new cycle; when T d >t 0 , the heating unit 100 is turned off, and at the same time the circulation pump 152 is turned off. After controlling the circulation pump 152 to be turned off, control the electric three-way valve 151 to be at the minimum safe step. It can be understood that the first preset time, the second preset time, and the adjustment steps of the electric three-way valve 151 can all be flexibly set by those skilled in the art and will not be listed one by one here.

[0044] In some alternative embodiments, a second one-way valve is further provided at the connection end of the water supply pipeline 300 and the heating unit 100. The second one-way valve is used to control the one-way flow of the liquid from the water supply pipeline 300 to the electric three-way valve 151, to prevent the liquid in the second connection pipeline 140 from entering the water supply pipeline 300 and avoid heat loss of the heating unit 100.

[0045] Further, the hot water system further includes a water supply pipeline 500. The first liquid storage module 210 is communicated with the heating water tank 120 through a third connection pipeline 400. The water supply pipeline 500 is communicated with the third connection pipeline 400. The water supply pipeline 500 is communicated with the outside to supply water to customers; when T c >t 1 , the heat storage unit 200 supplies liquid to the water supply pipeline 500; when t 2 <T c ≤t 1 , the heating unit 100 supplies liquid to the water supply pipeline 500; when T c ≤t 2 and T b >t 0 , the heating unit 100 supplies liquid to the water supply pipeline 500; when T b <t 0 and T a >t 0 , the heating unit 100 supplies liquid to the water supply pipeline 500; when T b <t 0 and T a <t 0 , when the heating component 122 is turned on and the heat pump main unit 110 operates at a third frequency, the heat storage unit 200 supplies liquid to the water supply pipeline 500; when T b >t 0 and T a >t 0 , the heating unit 100 supplies liquid to the water supply pipeline 500. In this embodiment, the water supply pipeline 500 is communicated with the third connection pipeline 400, which can reduce the number of valves, simplify the system control method, and save costs.

[0046] In some alternative embodiments, the hot water system further includes a water return pipeline 600. The water return pipeline 600 is communicated with the water replenishing pipeline 300 at the intersection 610. The water return pipeline 600 can be used to supply water to the heating unit 100 and / or the heat storage unit 200. The water return pipeline 600 can recycle the hot water that is not used up by the user end and supply it back to the hot water system of the present application embodiment, which is energy-saving and environmentally friendly.

[0047] Furthermore, the return water pipeline 600 of the embodiment of the present application includes a confluence part 610 connected to the make-up water pipeline 300. A return water pump and a third one-way valve are arranged on the return water pipeline 600. The third one-way valve is arranged between the return water pump and the confluence part 610, and is used to control the one-way flow of liquid from the return water pump to the confluence part 610. The make-up water pipeline 300 is connected to the tap water pipeline. When the user draws hot water from the heating water tank 120 and / or the heat storage unit 200 of the hot water system, it is necessary to make up water to the heating water tank 120 or the heat storage unit 200. The return water pump is opened when the user has a need. After being opened, it is mixed with tap water and divided into two paths to enter the heat storage unit 200 and the heating unit 100.

[0048] In some other alternative embodiments, the temperature T of the liquid in the heating water tank 120 is obtained a 、the temperature T of the liquid in the first liquid storage module 210 b 、the temperature T of the liquid in the second liquid storage module 220 c 、the temperature T of the liquid in the third liquid storage module 230 d The method is as follows: A first temperature sensor 121 is arranged at the upper part of the heating water tank 120 to obtain the temperature T of the liquid in the heating water tank 120 a ,a second temperature sensor 211 is arranged at the upper part of the first liquid storage module 210 to obtain the temperature T of the liquid in the first liquid storage module 210 b ,a third temperature sensor 221 is arranged in the middle part of the second liquid storage module 220 to obtain the temperature T of the liquid in the second liquid storage module 220 c ,a fourth temperature sensor 231 is arranged at the lower part of the third liquid storage module 230 to obtain the temperature T of the liquid in the third liquid storage module 230 d .

[0049] Refer to Figure 3 and combine with Figure 2 , Figure 3 shows a schematic structural diagram of the heat storage unit 200 according to an embodiment of the present invention. In this embodiment, the first liquid storage module 210 is a first hot water storage tank 212, the second liquid storage module 220 includes at least one second hot water storage tank 222 connected in series, and the third liquid storage module 230 is a third hot water storage tank 232. Among them, T c is the temperature of the liquid in the second hot water storage tank 222 located in the middle of the heat storage unit 200. In the embodiment illustrated in the present application Figure 3 ,the second hot water storage tank 222 includes three hot water storage tanks connected in series in sequence. The second temperature sensor 211 is arranged in the middle of the second hot water storage tank 222 among the three second hot water storage tanks 222.

[0050] The hot water system control method according to the embodiment of the present application divides the heat storage unit 200 into three liquid storage modules, then judges the current user demand according to the temperatures of the three liquid storage modules, and adjusts the frequency of the variable frequency heat pump main unit 110 according to the user demand, so as to realize the control of the closed-loop pressurized hot water system by controlling the frequency, and achieve a more energy-saving closed-loop pressurized hot water system. The hot water system control method according to the embodiment of the present application can set the heating frequency of the heat pump main unit 110 according to different user demands, ensure the customer demand while achieving energy-saving heat storage, and improve the user experience. At the same time, by setting different compressor frequencies, this solution reduces the frequent start and stop of the compressor, and avoids the problems of slow water temperature rise and low energy efficiency of the unit operation.

[0051] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made by using the content of the specification and drawings of the present invention under the inventive concept of the present invention, or any direct / indirect application in other related technical fields is included in the patent protection scope of the present invention.

Claims

1. A method for controlling a hot water system, characterized in that, this method is applied to a hot water system, and the hot water system includes: a heat storage unit, including a first liquid storage module, a second liquid storage module, and a third liquid storage module connected in series and communicated in sequence, the first liquid storage module and the third liquid storage module are respectively arranged at the head end and the tail end of the heat storage unit; and a heating unit, including a heat pump host and a heating water tank, the heat pump host can convey the heated liquid to the heating water tank, and the heating water tank is communicated with the first liquid storage module, so that at least part of the liquid in the heating water tank can enter the first liquid storage module; the method for controlling the hot water system includes: Obtain the temperature T of the liquid in the heating water tank a , the temperature T of the liquid in the first liquid storage module b , the temperature T of the liquid in the second liquid storage module c , the temperature T of the liquid in the third liquid storage module d ; When T c > t 1 , keep the heat pump main unit in an unstarted state; When t 2 <T c ≤t 1 , control the heat pump main unit to operate in the first frequency range; When T c ≤ t 2 and T b > t 0 control the heat pump main unit to operate within the second frequency range; When T b <t 0 When, control the heat pump main unit to operate within the third frequency range where t 0 is the target temperature, t 1 is the first preset temperature, t 2 is the second preset temperature, and t 0 > t 1 > t 2 , the third frequency range is higher than the second frequency range, and the second frequency range is higher than the first frequency range.

2. The method for controlling a hot water system according to claim 1, characterized in that, the method for controlling the hot water system further includes: When the heat pump main unit operates in the first frequency range until T d > t 0 , keep the heat pump main unit in a non-start state; When the heat pump main unit operates in the second frequency range until T c > t 2 , control the heat pump main unit to operate in the first frequency range; When the heat pump main unit operates in the third frequency range until T b >t 0 and T a >t 0 , control the heat pump main unit to operate in the second frequency range.

3. The method for controlling a hot water system according to claim 2, characterized in that, the heating water tank is provided with a heating component, and the heating component is used for heating the liquid in the heating water tank.

4. The method for controlling a hot water system according to claim 3, characterized in that, When T b <t 0 and T a >t 0 control the heat pump main unit to operate at the third frequency; When T b <t 0 and T a <t 0 When the time comes, control the heating component to turn on, and at the same time control the heat pump host to operate at the third frequency; When T b >t 0 and T a >t 0 , control the heating component to turn off, and at the same time control the heat pump main unit to operate at the second frequency; when T c >t 2 , control the heat pump main unit to operate at the first frequency; when T d >t 0 , keep the heat pump main unit in a non-start state.

5. The method for controlling a hot water system according to claim 4, characterized in that, the hot water system further includes: a makeup water pipeline, used for making up water for the heating unit and / or the heat storage unit; and a control component, used for controlling whether the makeup water pipeline provides liquid to the heating unit.

6. The method for controlling a hot water system according to claim 5, characterized in that, When T b <t 0 and T a <t 0 When this occurs, the control assembly controls the makeup water line to stop supplying liquid to the heating unit until Ta > t0, at which point the control assembly controls the makeup water line to supply liquid to the heating unit.

7. The method for controlling a hot water system according to claim 6, characterized in that, the control component includes a power water pump and an electromagnetic valve, and the power water pump is arranged between the electromagnetic valve and the heating unit; When T b <t 0 and T a <t 0 , control the heating component to turn on, at the same time control the heat pump main unit to operate at the third frequency, control the power water pump to turn off, and adjust the solenoid valve to the minimum safe step number so that the make-up water pipeline replenishes water for the heat storage unit; until Ta > t0, control the power water pump and the solenoid valve to open so that the make-up water pipeline gradually replenishes water for the heating unit again.

8. The method for controlling a hot water system according to claim 6, characterized in that, the heating unit further includes a first connection pipeline and a second connection pipeline communicated between the heat pump host and the heating water tank, the liquid in the heat pump host can enter the heating water tank through the first connection pipeline, and the control component is arranged on the second connection pipeline; the control component has a first state and a second state; when the control component is in the first state, the liquid in the makeup water pipeline enters the heat pump host after being mixed with the liquid from the heating water tank in the second connection pipeline; when the control component is in the second state, the liquid in the makeup water pipeline enters the heat storage unit; When T b <t 0 and T a <t 0 When this occurs, control the heating component to turn on, and at the same time control the heat pump main unit to operate at the third frequency, and control the control component to be in the second state so that the water supply pipeline replenishes water to the heat storage unit; until Ta > t0, control the control component to be in the first state so that the water supply pipeline gradually replenishes water to the heating unit again.

9. The method for controlling a hot water system according to claim 8, characterized in that, the control component includes: an electric three-way valve, the first end of the electric three-way valve is connected to the heat pump host, the second end of the electric three-way valve is connected to the heating water tank, and the third end of the electric three-way valve is connected to the makeup water pipeline; a circulating water pump, arranged between the first end of the electric three-way valve and the heat pump host; and a first one-way valve, arranged between the second end of the electric three-way valve and the heating water tank, and the first one-way valve is used for controlling the one-way flow of liquid from the heating water tank to the electric three-way valve.

10. The method for controlling a hot water system according to claim 9, characterized in that, the method for controlling the hot water system further includes: Obtain the average temperature T of the liquid in the heating water tank within the first preset time period a1 and the average temperature T of the liquid in the heat storage unit within the first preset time period c1 , according to T a1 , T c1 and the target temperature t 0 Control the valve opening of the electric three-way valve; When the hot water storage tank t 1 <T c1 <t 0 the electric three-way valve is at the minimum safe step number; When t 2 <T c1 ≤t 1 When the time is within this range, after controlling the electric three-way valve to maintain a fixed initial opening for a period of time e, start the circulating water pump; Detect the temperature of the heating water tank at the second preset time frequency. When T a1 > t 0 , the electric three-way valve increases by N steps, where N is a positive integer; When T a1 = t 0 , the electric three-way valve maintains the current number of steps; When T a1 <t 0 When, if T b >t 0 , control the electric three-way valve to gradually decrease by N steps; if T b ≤t 0 , control the electric three-way valve to decrease by N + k steps until it is closed to the minimum safety range of the electric three-way valve; until it is detected that T a1 -t 0 ≥0, reopen the electric three-way valve, where k is a positive integer; When T d > t 0 When the circulating water pump is controlled to be closed, adjust the electric three-way valve to the minimum safety step number.

11. The hot water system control method according to claim 5, characterized in that, the hot water system further includes a water supply pipeline, the first liquid storage module is communicated with the heating water tank through a third connection pipeline, the water supply pipeline is communicated with the third connection pipeline, and the water supply pipeline is communicated with the outside; When T c > t 1 the heat storage unit supplies liquid to the water supply pipeline; When t 2 <T c ≤t 1 the heating unit supplies liquid to the water supply pipeline; When T c ≤ t 2 and T b > t 0 the heating unit supplies liquid to the water supply line; When T b <t 0 and T a >t 0 the heating unit supplies liquid to the water supply pipeline When T b <t 0 and T a <t 0 when, in a state where the heating component is turned on and the heat pump main unit operates at a third frequency, the heat storage unit supplies liquid to the water supply pipeline; When T b > t 0 and T a > t 0 the heating unit supplies liquid to the water supply line.

12. The hot water system control method according to claim 5, characterized in that, the hot water system further includes a return water pipeline, the return water pipeline is communicated with the make-up water pipeline, and the return water pipeline can be used to supply water to the heating unit and / or the heat storage unit.

13. The hot water system control method according to claim 1, characterized in that, Obtain the temperature T of the liquid in the heating water tank a , the temperature T of the liquid in the first liquid storage module b , the temperature T of the liquid in the second liquid storage module c , the temperature T of the liquid in the third liquid storage module d . The steps include: obtaining the temperature T of the liquid in the heating water tank through a first temperature sensor arranged at the upper part of the heating water tank a , obtaining the temperature T of the liquid in the first liquid storage module through a second temperature sensor arranged at the upper part of the first liquid storage module b , obtaining the temperature T of the liquid in the second liquid storage module through a third temperature sensor arranged in the middle of the second liquid storage module c , obtaining the temperature T of the liquid in the third liquid storage module by arranging a fourth temperature sensor at the lower part of the third liquid storage module d .

14. The hot water system control method according to any one of claims 1-13, characterized in that, The first liquid storage module is a first hot water storage tank, the second liquid storage module includes at least one second hot water storage tank connected in series, and the third liquid storage module is a third hot water storage tank, where T c is the temperature of the liquid in the second hot water storage tank located in the middle of the heat storage unit.

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