WO2023201793A1 - Heat pump water heater and control method - Google Patents

Abstract

The present invention relates to the field of water heaters, and particularly relates to a heat pump water heater and a control method. The heat pump water heater comprises a water tank, a compressor, an evaporator, a condenser, a throttling device, a temperature sensor and a control unit, and further comprises a heating unit I, a hot water allowance sensing unit, a water flow sensing unit and an auxiliary heating device; the mounting mode of the heating unit I enables the heating unit I to be able to heat water output by the water tank; the auxiliary heating device is used for performing auxiliary heating on water in the water tank; the hot water allowance sensing unit is used for determining the allowance of hot water in the water tank, and controlling the working states of the heating unit I and the auxiliary heating device according to the hot water allowance, a temperature and information of the water flow sensing unit. The control method of the heat pump water heater comprises the following steps: step 1, acquiring hot water allowance, a temperature and water flow state information; and step 2, controlling the working states of a heat pump, the heating unit I and the auxiliary heating device according to the above information.

Description

Heat pump water heater and control method Technical field

The invention belongs to the field of water heaters, particularly a heat pump water heater and a control method.

Background technique

There are still some problems with existing heat pump water heaters. They are large in size, which limits the installation of urban users. Since the outdoor unit needs to be installed outdoors, the evaporator frosts, making it difficult to use in cold climate areas. There are also cases where the outdoor unit and the water tank are integrated. However, because the compressor is too powerful and blows cold air, it is not suitable to install it indoors in winter. When installed outdoors, the efficiency is low due to frost problems. When the weather is cold, electric heating pipes can only be used for heating. The heat exchange area of the evaporator and condenser must match the power of the compressor. If the compressor power is large, the corresponding area of the heat exchanger must be proportionally increased, and the cost remains high. For hot water for small households, Especially for use in rural areas, where they are usually elderly and save water. The additional purchase cost of using a heat pump water heater offsets the cost of saving electricity. Moreover, its installation location is too far from the water end, resulting in a poor experience, so most users still The choice of electric storage water heaters has led to the low popularity of heat pump water heaters, an energy-saving product. In order to solve this problem, some manufacturers have developed a wall-mounted air-energy water heater, which increases the capacity of the water tank to about 80 liters, uses a compressor of about 150W, and installs an electric heating pipe of about 3000W in the water tank. However, this type of heat pump water heater It is mainly an electric water heater. The heat pump only serves as a supplement to electric heating, and the energy-saving effect is very limited. For example, when a part of the hot water in the water tank is used up, if a heat pump is used for heating alone, the power is too low and the heating is too slow. In winter, it may even take more than 8 hours to heat a tank of water. In order to allow users to have hot water available at any time, they have to Using electric heating pipes and heat pumps for heating together, the electric heating pipes must heat the water to at least 45 degrees before stopping. Considering the use of the elderly, it may even need to be heated to 50 degrees before stopping. There is almost no space left for the heat pump to heat alone. This is also The reason why household heat pump water heaters need to increase the compressor power. At the same time, the efficiency of the heat pump water heater is also affected by scale. When scale forms on the surface of the condenser, the thermal conductivity drops by dozens of times or even more, causing the heat pump to be inefficient or even unable to heat. At the same time, the heat pump water heater also deposits a large amount of sediment, bacteria, algae and scale. At the water temperature of the heat pump water heater, a large number of bacteria will breed, affecting water hygiene.

technical problem

In order to solve the problems of existing heat pump water heaters, the present invention proposes a new solution, which solves a series of problems such as installation space limitations, installation area limitations, energy saving, scale, and cost of existing heat pump water heaters, and provides a basis for wider promotion and even expansion of heat pump water heaters. Replacing other types of water heaters creates sufficient conditions and can make a greater contribution to global energy conservation and emission reduction.

Technical solutions

In order to solve the deficiencies of existing water heater technology, the present invention provides a new technical solution.

The object of the present invention is solved by the following technical solutions:

A heat pump water heater includes a water tank, a compressor, an evaporator, a condenser, a throttling device, a temperature sensor, and a control unit. It also includes a heating unit, a hot water residual sensing unit, a water flow sensing unit, and an auxiliary heating device. The heating unit one is installed in such a way that it can heat the water flowing out of the water tank. The auxiliary heating device is used to auxiliary heat the water in the water tank. The hot water residual sensing unit is used to determine the amount of available hot water in the water tank. The remaining amount controls the working status of the heating unit 1 and the auxiliary heating device according to the remaining amount of hot water, temperature and the signal of the water flow sensing unit.

Optionally, the auxiliary heating device includes a water flow driving device and a water flow control device. The water tank, heating unit 1, water flow driving device, and water flow control device are connected together to form an auxiliary heat heating circuit. The water flow driving device drives the water flow through The heating unit cyclically heats the heat storage medium in the water tank. The water flow driving device can also be used for one or more of water outlet pressurization, zero cold water circulation, and automatic cleaning. The water flow control device is used to limit the direction of the water flow. , switch the water flow path, control the ratio of hot and cold water, and control one or more of the flow rates.

Optionally, a settling device is also included. The settling device is connected in series on the water outlet channel of the heat pump water heater. The water inlet end of the water flow driving device is connected to the bottom of the water tank. The settling device is located on the water flow driving device. on the circulation path.

Further, the water flow control device includes a stepper motor and a valve.

Optionally, the hot water remaining amount sensing unit includes at least two temperature sensors. The temperature sensors are installed at different water levels in the water tank. The temperature sensors at different positions measure the temperature of the water tank and calculate the hot water remaining amount.

Optionally, the hot water remaining amount sensing unit includes the water flow sensing unit and at least one temperature sensor. The water tank is estimated based on the data of the temperature sensor, the hot water output measured by the water flow sensing unit, and the operating parameters of the auxiliary heating device and the heat pump. Current hot water remaining amount.

Optionally, the auxiliary heating device includes a heating unit 2, and the heating unit 2 is used to heat water in the water tank.

Optionally, the control unit, heating unit one, water flow sensing unit, water flow driving device, and water flow control device are integrated together to form an auxiliary module. The auxiliary module can be further integrated with the heat pump assembly to form a heating module. Through the water flow The interface, electronic and electrical interface and fastening device cooperate with the thermal storage module to form a modular structure that is easy to disassemble and assemble.

A control method for a heat pump water heater, the control method includes the following steps:

Step 1. Obtain hot water remaining amount, temperature, and water flow status information;

Step 2. Control the working status of the heat pump, heating unit 1 and auxiliary heating device based on the above information;

Optionally, its control methods also include:

Step 1. Compare the hot water temperature t at the bottom of the water tank with the water tank set temperature t0. If it is lower than the water tank set temperature, the heat pump starts. Otherwise, the heat pump stops. Go to step 2;

Step 2. Obtain the available hot water balance Q in the water tank;

Step 3. Is the outlet water flow sensing unit activated? If not, go to step 4; if yes, go to step 6;

Step 4. Is the residual amount of hot water Q in the water tank less than N1? If yes, go to step 5; if not, return to step 1;

Step 5. Execute the auxiliary heating mode and return to step 1;

Step 6. Compare whether the temperature t1 of the upper part of the water tank is greater than or equal to the outlet water setting temperature t2? If yes, go to step 7; if not, go to step 14;

Step 7. Is the residual amount of hot water Q in the water tank greater than N2? If yes, go to step 13; if not, go to step 8;

Step 8. Is the residual amount of hot water Q in the water tank greater than N3? If yes, go to step 12; if not, go to step 9;

Step 9. Is the residual amount of hot water Q in the water tank greater than N4? If yes, go to step 11; if not, go to step 10;

Step 10. High-grade auxiliary heat water supply mode, return to step 1;

Step 11. Mid-range auxiliary heat water supply mode, return to step 1;

Step 12. Low-grade auxiliary heat water supply mode, return to step 1;

Step 13. Without auxiliary heat water supply mode, return to step 1;

Step 14: Compare whether the temperature t1 of the upper part of the water tank is less than the outlet water set temperature t2-q1. If yes, go to step 10. If not, go to step 8.

beneficial effects

The heat pump water heater and control method of the present invention, through a series of innovative designs of traditional heat pump water heaters, enable the heat pump water heater to greatly reduce the compressor power without affecting normal use or energy saving effects, evaporator, condensation The volume of the water heater is reduced proportionally, so that the volume of the entire water heater can be equal to that of an ordinary storage water heater of the same volume, and the installation location of urban users is not limited; at the same time, whether the heat pump water heater of the present invention is made into an integrated or split type, The host can be installed indoors, where the indoor temperature is high. Since the compressor power is small, it basically does not affect the indoor temperature and appearance, so it can be used in any cold area, eliminating regional restrictions. The invention also realizes the functions of automatic scale removal, automatic cleaning, constant temperature water outlet, water outlet pressurization, zero cold water circulation, hot water temperature increase and volume increase, etc. without increasing the cost. Even if the invention is used in a traditional heat pump water heater with a larger power compressor, it still has outstanding advantages, such as effectively removing scale, quickly providing hot water by rising from the top, and heating the outlet water to effectively increase the water content. Capacity and other advantages. For example, using a low-power compressor solution saves costs compared with traditional heat pump water heaters, allowing air energy to be used by a wider range of people, which can make a huge contribution to energy conservation and emission reduction.

Description of the drawings

The present invention will be further described below in conjunction with the accompanying drawings and examples.

Figure 1 is a schematic structural diagram of a wall-mounted integrated heat pump water heater.

Figure 2 is a schematic structural diagram of a wall-mounted integrated heat pump water heater.

Figure 3 is a schematic structural diagram of a wall-mounted integrated heat pump water heater.

Figure 4 is a schematic structural diagram of a vertical integrated heat pump water heater.

Figure 5 is the structural schematic diagram 2 of the vertical integrated heat pump water heater.

Figure 6 is the structural schematic diagram 3 of the vertical integrated heat pump water heater.

Figure 7 is a schematic structural diagram of a vertical split heat pump water heater.

Figure 8 is the structural schematic diagram 2 of the vertical split heat pump water heater.

Figure 9 is the structural schematic diagram 3 of the vertical split heat pump water heater.

Figure 10 is a schematic diagram of the module solution.

Figure 11 is the schematic diagram 2 of the module solution.

Figure 12 is a flow chart of a heat pump water heater control method

Figure 13 is a logic diagram of a heat pump water heater control method

In the picture:

1. Water tank 2. Compressor 3. Evaporator 4. Condenser 5. Heating unit 1 6. Water flow driving device 7. Water flow sensing unit 8. Water flow control device 9. Throttle device 10. Settling device 11. One-way valve 12. Temperature sensor 13. Water inlet 14. Hot water extension pipe 15 , Drainage pipe 16. Heat pump host 17. Cold water nozzle 18. Second drainage pipe 19. Hot water connecting pipe 20. Cleaning nozzle 21. Circulation water inlet pipe 22. Circulation water outlet pipe 23. Heating unit two 24. Water outlet 25. Shared branch Road 26, heat pump module 27, auxiliary module 28, thermal storage module 29, heating module

Best Mode of Carrying Out the Invention

It should be noted that, on the premise of no conflict, the embodiments and features in the embodiments of this application can be combined with each other, and any solution that can be easily imagined through this patent is within the protection scope of this patent. The present invention will be further described below in conjunction with the accompanying drawings and examples.

Agreement: 1. In this manual, the integrated heating part using compressor, condenser, evaporator, throttling device, etc. is collectively called a heat pump; 2. The water flow driving device 06 includes but is not limited to a water pump. In this manual, the water pump is agreed for convenience. It is equivalent to the water flow drive device; 3. Auxiliary heat heating and auxiliary heat circulation heating both refer to using a heater other than a heat pump to assist in heating the water in the water tank or to reheat the water flowing out of the water tank. Auxiliary heat heating includes but It is not limited to auxiliary heat circulation heating. When the word "circulation" is used, it means that a water pump is involved in heating the water in the water tank during heating. 4. Some of the pipelines in the schematic diagram of the instruction manual are directly represented by lines, while others draw the shape of the pipeline (such as a drainage pipe). It is agreed that these two forms are equivalent.

Embodiment 1

1 to 3 are schematic diagrams of Embodiment 1. This embodiment is a variety of structural forms of horizontal heat pump water heaters. As shown in Figure 1, the main part of heat pump heating is composed of compressor 02, evaporator 03, condenser 04, and throttling device 09. The heating unit 05, the water flow driving device 06, the water flow control device 08, the settling device 10, the one-way valve 11 and some connecting pipes constitute the outlet water secondary heating and auxiliary heat circulation heating part. The heating unit 05 can output the water from the water tank. The water is heated twice, and the water in the water tank can also be heated by auxiliary heat circulation. The control unit (that is, the control circuit board, not shown in the figure) can calculate the remaining amount of hot water in the water tank 01 based on the temperature values of the multiple temperature sensors 12, and compare it with the set value to determine whether a heating unit is needed. A pair of output water is reheated or the water in the water tank is heated by auxiliary heat circulation. In Figure 1, multiple temperature sensors 12 are used to measure the temperature of water at different water levels, and the remaining amount of hot water is calculated based on the temperature and the position of each sensor. Figure 1 shows a total of 4 temperature sensors (of course it can be other numbers of temperature sensors). One is installed at the bottom of the water tank to sense the bottom water temperature and is used to determine the start and stop of the heat pump; in the middle and upper part of the water tank, three temperature sensors are installed. A temperature sensor is used to measure the water temperature at the corresponding height position of the water tank. After the size of the water tank is determined, the corresponding height position corresponds to the corresponding water volume. For example, in a 100-liter water tank, the temperature sensor is installed in the middle. Through the value of this sensor You can be sure that at least 50 liters of water is not less than this temperature value. However, it is not accurate to use only one sensor to measure the hot water remaining amount (there are two sensors including the bottom temperature sensor. The hot water remaining amount sensing unit described in the claims includes at least two temperature sensors including the bottom sensor), for example The temperature of the hot water in the upper layer may be much higher than the temperature where the sensor is installed, thus underestimating the remaining amount of available hot water, resulting in excessive use of electric auxiliary heat and increased energy consumption. However, as long as the temperature sensor is installed in a suitable position, using only one sensor to detect the remaining amount of hot water is also feasible in the structure of this patent. For example, the installation position is 60 to 80 liters away from the top of the hot water (of course, It can be other values). When the temperature of the temperature sensor at this position is less than a certain temperature value (such as 30 degrees), auxiliary heat is used to heat to this temperature value, which can make the water heater at least in the case of auxiliary heating of the heating unit. Can provide 60~80 liters of hot water at 45 degrees. Of course, the water tank temperature detection only uses two temperature sensors (one of which must detect the temperature at the bottom of the water tank. Of course, installing this temperature sensor at a higher position at the expense of estimating the bottom water temperature is also within the scope of this patent) Inaccurate detection of the remaining amount of hot water will increase energy consumption anyway. Installing multiple sensors at different heights can more accurately estimate the remaining amount of hot water. When the water heater does not supply hot water to the outside, when it is measured that the remaining amount of hot water in the water tank cannot meet the requirements for one bath even by starting the auxiliary heating of the heating unit, it is necessary to quickly make the remaining amount of hot water in the water tank reach the level of one bath. requirements, so as to have a good user experience. When the heating unit 05 is required to assist in heating the water in the water tank, the water flow control device 08 cuts off the hot water connecting pipe 19 and connects the common branch 25 and the drainage pipe 15. The water flow driving device 06 is started, and the water in the water tank passes through the drainage pipe 15. , water flow control device 08, water flow driving device 06, heating unit 05, settling device 10, one-way valve 11, water flow sensing unit 07, and then flows into the top of the water tank through the hot water extension pipe 14. At this time, the water flow control device can also pass through Control the size of the water flow to adjust the temperature so that the circulating heated water flows into the water tank at a set temperature, for example, it can be set to 28 degrees (since the heating unit can be used to heat the water twice, the auxiliary heat can heat the water in the water tank The temperature should be as low as possible, leaving more space for the heat pump to heat alone). In this way, the hot water rises from the top, avoiding the mixing of hot and cold water. You can also decide how many liters of hot water to heat according to your needs. For example, after the temperature sensor N reaches a certain temperature value, the circulating heating stops, and the temperature sensor N The installation location is also important. For example, the capacity from the installation location to the top of the water tank is 60 liters. At this time, when the temperature sensor N senses that the water temperature is 28 degrees, it can be determined that there are at least 60 liters of hot water at 28 degrees in the water tank. . Calculating the hot water margin in the case of multiple sensors includes at least the following two methods: 1. Segment calculation method. This calculation method is to make a section parallel to the horizontal plane of the water tank based on the installation position of the sensor. The distance between the two temperature sensor sections is The water temperature is based on the sensor with a lower position. Multiply the water volume between sections by the water temperature to get a value. Add the values of each sensor to get the hot water margin. The top sensor is the ratio between its cross section and the hot water in the water tank. The volume formed by the horizontal plane. Once the geometry of the water tank and the position of each sensor are determined, the volume of each layer of water has been determined and stored directly in the software. Subsequently, only the temperature values of each sensor need to be multiplied by it and then accumulated; 2. Average calculation method. The average calculation method is to add the temperatures of the three sensors installed in the middle and upper part of the water tank in Figure 1, divide by three to get the average, and then multiply the bottom one of the three sensors by the level of hot water in the water tank. Volume (water volume), which is a fixed value after the water tank shape and sensor installation position are determined, is directly stored in the software. You only need to calculate the average value of the three temperature sensors and multiply it to get the hot water margin. The above calculation of hot water residual can also consider a temperature threshold value. When the water temperature is lower than this value, it is directly set to zero. For example, when the water temperature is 18 degrees, it cannot be obtained at the appropriate temperature through auxiliary heating by the heating unit. The right amount of water, meaningless. From the perspective of energy saving, when the heating unit is working, the heat pump system must also be working at the same time. The amount of water required for a bath mentioned above is different for each user, so this value can be designed to be adjusted by the user, or the company can set it to a higher value from the factory (in this case, the energy saving effect is not that good, and when the water tank capacity is not large enough, it may Leading to excessive use of electric heating). Due to some characteristics of heat pump heating, ordinary heat pumps can generally only heat hot water to about 55 degrees. Although medium and high temperature heat pumps can heat to higher temperatures, they will increase the cost and increase the problem of scaling in the condenser (once the heat exchanger The heating efficiency of the water tank will be extremely low due to scaling and extremely low heating efficiency), so when electric auxiliary heating is needed, the heating temperature of the water tank should be as low as possible. This is why this patent must enable the heating unit 105 to reheat the water coming out of the water tank. For example, if the power of the heating unit 1 is 5KW, it can heat the water with a flow rate of 5 liters per minute by about 15 degrees. In this way, only the water in the water tank needs to be heated. The stored water is heated to 30 degrees, and hot water of 45 degrees can be provided through one or two heatings by the heating unit. At the same time, as mentioned above, the structure of the present invention makes the hot water for circulating heating rise from above. The electric auxiliary heating does not need to heat the entire water tank to 30 degrees, but can choose to heat only 60 liters or other water. The amount of water is enough for one person to take a bath, and then the heat pump is used to heat it alone, maximizing the energy saving effect. As long as one person can bathe at the fastest speed at all times, the actual effect is equivalent to a relay bath with unlimited water. In the actual scenario of home use, a large amount of water is usually used at night. Some people who are accustomed to taking a shower in the morning use a large amount of water in the morning. Whether they use a large amount of water in the morning or at night, even if the power of the compressor reaches 150W (the actual heat production is about 570W), When the tap water temperature is 5 degrees, the water heater has enough time to use heat pump heating to raise 150 liters to 180 liters of water by 50 degrees. If the water tank has a large volume, such as 200 liters, the compressor power only needs to be about 200W. This patented electric auxiliary heating structure and hot water residual sensing can solve the problem that when the hot water is almost used up, it takes a long time (possibly more than 8 hours or even 10 hours) to heat the whole box of hot water again. Available temperature issues. With many new functions such as hot water residual sensing, secondary water heating, and hot water heating from the top down, it can use electric auxiliary heat as little as possible to achieve the best energy-saving effect. The reason why traditional heat pump water heaters use high power is to ensure that hot water is available at any time or as soon as possible. However, even with a power of 1.5 HP, it is inefficient or even unable to heat when the temperature is too low in winter, so it needs to be installed in a water tank. The electric heater is used as auxiliary heat, but the heater installed in the water tank cannot reheat the outlet water, so the entire tank of water must be heated directly to the bathing temperature, such as 45 degrees, leaving almost no space left for the heat pump to heat alone. How much, and it is in a high temperature area, so the efficiency is lower. As shown in Figure 1, when the water heater supplies hot water to the outside, cold water enters from the water inlet end 13 under the tap water pressure, and the hot water in the water tank passes through the hot water extension pipe 14, the hot water connecting pipe 19, and the water flow control device 08 , the common branch 25, the water flow driving device 06, the heating unit 05, the settling device 10, the water flow sensing unit 07, and the water outlet end 24 flow out. At this time, the outlet water flow sensing unit 07 starts. The water flow control device 08 realizes constant temperature control by adjusting the ratio of hot and cold water. The cold water enters the water flow control device 08 from the bottom of the water tank through the drainage pipe 15. When all the hot water in the water tank is of the same temperature, the water flowing out from the bottom is still hot water at first, which cannot achieve the constant temperature effect. However, as cold water is added, the bottom will soon be cold water. When using hot water, when the temperature in the water tank is too low or the remaining hot water is insufficient, the heating unit 05 works to reheat the outlet water. Sometimes the water temperature on the top floor is high, but the amount is small. For example, there is only 20 liters of water at 55 degrees, and almost all the water below is cold water. In this case, when the user uses hot water, the heating unit 105 must also be heated at full power. Then, the water flow control device 08 adjusts the ratio of hot and cold water to set the output water temperature to a constant temperature output (of course, constant temperature is not a restriction of this patent, and non-constant temperature water is also within the scope of protection of this patent). When the water heater supplies water to the outside, the heating unit 105 determines whether the outlet water needs to be reheated based on the remaining amount of hot water in the water tank and the water temperature, and determines how much power to use for heating.

As shown in Figure 1, the function of the settling device 10 is that when the water heater performs automatic cleaning or auxiliary heat cycle heating, the impurities extracted from the bottom of the water tank are deposited in this device. The flow rate can be reduced by increasing the flow cross section, and then through some bends. The flow or vortex structure causes the solid matter in the low-speed fluid to settle. When the water heater supplies water to the outside, these deposited impurities flow out with the water. Correspondingly, the structure of the water inlet end 13 extending into the water tank causes the incoming water to wash the bottom surface, and the scale at the bottom of the water tank is rushed to the end where the drainage pipe 15 is located, so that the scale flows out with the water when the water heater discharges cold water. The auxiliary heat circulation heating and automatic cleaning are brought into the settling device. A filter screen can also be placed in the drain pipe 15, and large pieces of scale will be deposited in the drain pipe to prevent large pieces of scale from entering the water flow driving device 06 and jamming the impeller, and also preventing large pieces of scale from blocking the valve and shower head. Install a ball valve on the drainage pipe 15 to drain and drain water regularly. Look at the second drain pipe 18 on the water tank. The position of this second drain pipe is slightly higher than the condenser 04. Its function is to drain the water in the water tank during automatic cleaning (the tap water inlet needs to be turned off during automatic cleaning). Make the remaining water just submerged in the condenser 04. The user can inject edible white vinegar or other descaling agents into the water tank from this port. The machine intermittently starts the water flow drive device 06 to circulate the water intermittently. After a period of time, the entire auxiliary heat cycle heating channel, The scale at the bottom of the water tank and condenser 04 is dissolved. This structure can effectively solve the scale problem of traditional water storage water heaters.

Although the core goal of this patent is to miniaturize the heat pump to solve its installation space limitations and usage area restrictions, the structure of this patent also has its advantages when used in high-power heat pump water heaters. For example, it can prevent scale deposition, and a pair of heating units can produce two water outlets. Secondary heating can effectively increase the volume. When auxiliary heat is used to heat the water in the water tank, the hot water rises from the top, making it possible to quickly and quantitatively heat an appropriate amount of water, making it more convenient and energy-saving.

The water flow drive device 06 can generally use a DC brushless water pump, which is small in size, high in lift, large in flow and long in life. Of course, other functions such as diaphragm pumps, gear pumps, and piston pumps can also be used, but such pumps are not ideal here. Even using a motor to drive an impeller device to drive water flow can also achieve the function. The water flow control device 08 is generally considered to be composed of a stepper motor and a valve. The valve is designed to adjust the ratio of the two-way fluid, the single-way water flow, and the size of the single-way flow. Therefore, this valve can realize constant temperature water outlet by controlling the ratio of hot and cold water and the flow rate of water, and realize the functions of external constant temperature water supply, auxiliary heat circulation heating and automatic cleaning by switching different circulation paths. The water flow control device 08 can also use two valves to control two water channels respectively to achieve the same function. However, this method has a more complex structure and high cost. It is not a preferred solution, but it is also within the protection scope of this patent. The one-way valve 11 prevents hot water from flowing out directly from this branch. If the hot water flows out directly from here, although the function can be achieved, the constant temperature control will become more troublesome. The heating unit 105 can use any form of electric heater, such as resistance wire heater, heating film heater, electromagnetic heater, ceramic heater, etc.

Figure 2 removes the settling device 10 on the basis of Figure 1. At the same time, the position of the water inlet end 13 and the drain pipe 15 makes it impossible for the cold water inlet to effectively flush the scale to the drain pipe. Compared with Figure 1, Figure 2 also reduces the number of three temperature sensors 12 used for hot water residual detection. This structure can utilize the temperature of the temperature sensor 12 installed at the bottom of the water heater, as well as the working time of the heat pump and heating unit 105, and The inner tank water flow sensing unit 07 cooperates to calculate the remaining amount of hot water. The calculation method is: when the temperature sensor 12 reaches the set value, the remaining hot water is the water tank capacity Qa, and the hot water flow sensing unit 07 (not the one installed at the water outlet 24) measures the hot water output of the water tank 01 each time. And accumulate Q1+Q2+Q3+…=Qn, the accumulated hot water volume heated by the heat pump and heating unit is Qt. Qt should be heated according to the tap water inlet temperature to the water tank set temperature to calculate the heated water volume, the power of the heater, and the power of the heat pump. The efficiency, heating time, inlet water temperature, and water tank setting temperature are all fixed values, and the calculation is very simple. Use Qa- Qn+Qt equals the hot water margin Q. Due to the problems of heat dissipation and hot water output rate, this value is multiplied by a coefficient to obtain the available hot water margin. Whenever the temperature sensor at the bottom of the water tank reaches the set temperature of the water tank, the above data is cleared and the hot water residual is reset to Qa. In this way, the hot water residual of the water heater is measured cyclically, which is also more accurate. The working status of the heating unit one (05) and the auxiliary heating device is determined based on the remaining amount of hot water and the working status of the outlet water flow sensing unit.

Of course, there are other more accurate algorithms for calculating water volume using a temperature sensor combined with a water flow sensing unit, such as a heat pump. If a low-power heat pump is used, it is actually impossible to heat a certain flow rate of tap water to the water tank set temperature in a short period of time. It may only increase by a few degrees, but it is not available, so the remaining amount of hot water generated by heat pump heating cannot be calculated by the simple algorithm above. On the one hand, this calculation method is not complicated, and on the other hand, it is not the focus of this patent, so it is omitted here. Pass.

Figure 3 adds a heating unit 23. When auxiliary heat is needed to heat the water in the water tank, the heating unit 23 works. When the water heater supplies water to the place and requires auxiliary heating, the heating unit 05 works. At this time, the water flow control device 08 For thermostatic control only. This kind of structure does not have a water flow drive device, so it cannot realize automatic cleaning, nor can it realize zero cold water circulation and water outlet pressurization. When using auxiliary heat to heat the water tank to store water, it cannot allow the water to heat up from the top, which is far inferior to Figure 1 and Scheme of Figure 2. However, since cold water can be supplied through the water flow control device 08, especially when the tap water temperature is high, the cold water flow is larger, which can effectively take away the scale. At the same time, the outlet structure of the water inlet end 13 allows it to blow all the scale at the bottom of the water tank. The end where the drain pipe 15 is located increases the scale cleaning effect. Compared with traditional heat pump water heater products, it still has certain advantages and is also a feasible solution.

The water tank in this embodiment adopts a horizontal structure. When a low-power compressor is used, it can be made into an integrated wall-mounted type. The water tank capacity can be made from 60 to 100 liters. The appearance and volume are similar to traditional electric water storage water heaters. , at this capacity, using this patented technology, the compressor can reach 150W, and can be smaller in places with higher temperatures. The evaporator and condenser are accordingly reduced in proportion, which greatly reduces the cost. This wall-mounted type can be installed in small urban apartments, and can be hidden in the ceiling, taking up no space, and the water heater is close to the water terminal, providing a better experience and more energy saving. This horizontal structure can also be integrated with furniture such as bathroom cabinets. Of course, the heat pump water heater's main unit and water tank are split, and the compressor is high-power or low-power, which are all within the scope of protection of this patent. Just using a low-power compressor, combined with this patented technology, will have more advantages. When the host is installed indoors, the noise is about the same as that of a refrigerator, and it will not affect the indoor temperature and appearance. It can also be used in the north where the climate is very cold in winter, and it is very efficient. Extremely high (due to heating). This kind of low-power heat pump only recovers a very small part of the heat energy that would otherwise be dissipated through walls, doors and windows and uses it for hot water, without affecting the indoor temperature.

Embodiment 2

As shown in Figures 4 to 6, this embodiment adopts an integrated structure of a vertical water tank. As shown in Figure 4, compared to the first embodiment, there is no water flow control device 08, so there is no way to achieve constant temperature water outlet and auxiliary heat circulation heating. The method is also different. It absorbs water from the top, is heated by the heating unit 105, and then flows back to the middle of the water tank through the one-way valve 11 (this position is not arbitrary. Generally, a position with 60 to 100 liters of water from the top of the water tank is considered more appropriate). Its advantage is that the temperature in the upper part of the water tank is generally higher, so it can be heated to the appropriate temperature faster when water is urgently needed. However, this method has more disadvantages, such as the inability to remove scale and the inability to maintain water at a constant temperature. The water tank in Figure 4 uses two temperature sensors 12 for temperature sensing and hot water residual sensing. The method for calculating the hot water residual is the same as that introduced in Embodiment 1. The structure in Figure 5 can realize constant temperature water outlet and can effectively remove scale. However, with this structure, the water flow drive device 06 in the figure cannot perform zero cold water circulation and water outlet pressurization. At this time, the water flow drive device can only operate in the auxiliary heat cycle heating or Used during automatic cleaning. The structure in Figure 6 is a hybrid solution of Figure 2 and Figure 1. On this basis, the horizontal water tank is changed into a vertical water tank, which will not be described again.

Embodiment 3

Figures 7 to 9 are several structural schematic diagrams of the split solution of this patent. As shown in Figure 7, the water tank 01 and the heat pump host 16 adopt a split structure. The heating unit 05, the water flow driving device 06, the water flow sensing unit 07, the settlement The installation method and functions of the device 10 and other components are exactly the same as in Figure 1 in the first embodiment. A cold water nozzle 17 is added to the top of the water inlet end 13. When water enters, the condenser 04 and the bottom of the water tank can be flushed to increase the descaling effect. The advantage of the split type is that in areas with cold winters, when the water tank capacity is large and must be installed outdoors (such as balconies and roofs), the low-power heat pump host can be installed indoors. Even the horizontal heat pump water heater in Embodiment 1 can also be split type. Because the bathroom space is small, if the bathroom door and window are too tightly sealed and are always closed, the warm air in the room cannot be replenished in time. Affects the efficiency of the heat pump. At this time, the heat pump host can be installed in a split type indoors with a larger space. It is unacceptable to install a high-power heat pump host indoors. Not only does it make noise, it also blows cold wind in winter, and it is large and unsightly. The difference between Figure 8 and Figure 7 is that the water outlet end of the auxiliary heat circulation heating is moved to the top of the water tank, and a cleaning nozzle 20 is added at the outlet. When the water heater is in cleaning mode, the water in the water tank is discharged through the second drain pipe 18. Drain the water to a position that just submerges the condenser 04, add white vinegar or other descaling agents into the water tank, the water flow driving device 06 operates intermittently or continuously, and the entire inner wall of the water tank can be washed by cleaning the nozzle. The reason why we do not use a full tank of water when cleaning is mainly due to the concentration of the descaling agent. From the perspective of user safety and psychological acceptance, it is more acceptable to use edible white vinegar for cleaning. After all, white vinegar is food. If the water in the full water tank is added to a concentration that can effectively remove scale, the white vinegar required for one cleaning will be too expensive and troublesome to add. Using this patented technology, if the water tank has a large capacity of 300 liters, the compressor only needs about 260W, which is only about one-eighth of the power of a traditional household heat pump water heater. The heat exchange area of the condenser is also reduced proportionally. , no need to fill the entire water tank like a traditional heat pump. Figure 9 is a split water circulation structure. With this structure, maintenance and after-sales service are more convenient, especially when the heat pump host is very small, such as the size of a desktop computer case or smaller. To replace the heat pump host, you only need to remove the circulating water inlet pipe 21 and the circulation The joint of the water outlet pipe 22 is sufficient.

Embodiment 4

Figures 10 and 11 are schematic diagrams of Embodiment 4 of this patent. This embodiment adopts a modular design. As shown in Figure 10, the water tank, compressor, evaporator, condenser, throttling device, temperature sensor, etc. are integrated together. The heat pump module 26 is constituted, and the control unit (that is, the control circuit board and other electronic and electrical components, not shown in the figure), the heating unit 1, the water flow driving device, the water flow sensing unit, the water flow control device, the settling device, the one-way valve, etc. Integrated together to form the auxiliary module 27. Of course, the elements in the auxiliary module can be any available combination of parts included in this patent, and are not limited to the parts shown in the figures. The two modules are connected by water connectors and electronic and electrical connectors. The advantage of modularity is to facilitate maintenance and after-sales service. Because there are many electronic and electrical components, problems with any one part will cause machine failure. Therefore, these components are integrated together to form a module, and an easy-to-disassemble structure is used to connect to the heat pump module. If If the machine fails, just replace the small module as a whole. This way, professional after-sales personnel are not needed. If the compressor fails, more professional maintenance personnel will need to come to the door. With branded compressors, stability can be guaranteed. It is generally less prone to failure during its lifetime. The modularization in Figure 11 is more thorough. The heat pump and auxiliary devices are integrated to form the heating module 29. The water tank, the insulation layer and the temperature sensor that must be installed on the water tank are integrated to form the heat storage module 28. In fact, if the two modules are assembled on At the same time, the temperature sensor on the water tank can also be integrated into the heating module 29. If multiple sensors at different heights are used to sense the remaining amount of hot water, the sensors can be installed into the conduit, and the conduit is inserted into the water tank; if it is a temperature sensor In conjunction with the water flow sensing unit to detect the remaining amount of hot water, the temperature sensor can be directly installed in the heating module 29, and a thermal conductive column is used to guide the temperature of the water tank. Of course, there are many other forms, including infrared temperature measurement. The modular type in Figure 11 can also be installed separately, and the heat storage module and the heating module can be connected with water pipes. If the heat pump uses low power, the heating module is only as big as a computer case or smaller, and can be installed in a place that is easy to operate, and the water tank can be hidden somewhere else.

All the above embodiments only illustrate the structural form of this patent, but to achieve the best effect, a suitable control method is also required. The basic idea of the control method is: experience first, energy saving first. A control method is provided based on the above embodiments. First, set a target: at any time, the water heater is guaranteed to be continuously used for 15 to 20 minutes at a flow rate of 4 liters and a temperature of 45 degrees (of course, this target can also be other values) , if the hot water reserve in the water tank does not meet this requirement, the fastest heating method is used to meet this requirement (the so-called fastest method is to heat the heat pump and the auxiliary heating device together). The specification uses specific data to facilitate understanding, and assumes that the power of heating unit one and heating unit two is 5KW. Based on this, combined with the structure of this patent, the control method of this water heater is given. Figures 12 and 13 are flow charts and logic diagrams of the water heater control method in this embodiment. Figure 12 is a flow chart, which provides the overall direction of the water heater control method. According to the hot water residual amount, temperature and water flow status (also That is, whether the water heater supplies hot water to the outside) to control the working status of the heat pump, heating unit and auxiliary heating device. Figure 13 is a logic diagram of this embodiment. This logic diagram provides a set of specific control methods under the overall scheme of the flow chart. Here, each step in the logic diagram is introduced in detail:

t in S201 represents the current water temperature in the lower part of the water tank, t0 represents the set temperature of the water tank, judge the condition t<t0, if yes, execute S202, and the heat pump starts heating; if no, execute S203. In order to prevent the pump from starting frequently, the value of t0 will be set in a range, such as how many degrees below this value it will restart. Next, S204 is executed to obtain the hot water remaining quantity Q. The method of obtaining the hot water remaining quantity has been introduced in Embodiment 1. Execute S205, which is water flow judgment, to determine whether the user is using hot water. If so, execute S208; if not, execute S206. S206 determines whether the hot water margin Q in the water tank is less than N1. The value of N1 represents that the current hot water margin of the water tank can provide an appropriate amount of hot water when the heating unit uses a pair of water outlets for electric auxiliary heating. This value is determined by the factory. The value is preset or set by the user. If it is greater than or equal to N1, for example, if N1 is 1680 liters (28 degrees * 60 liters, 60 liters of 45-degree water can be provided through electric auxiliary heating). When the temperature is higher, the amount of water can be smaller to meet the usage requirements. When the temperature is lower, the water volume needs to be more to meet the usage requirements. However, if the temperature is lower than 28 degrees or other values (such as 20 degree or lower), then under the appropriate flow rate, no matter how much water in the water tank is, it will not be able to provide hot water with the right temperature (although the product of 200 liters of water times 20 degrees is far greater than 1680 liters), so when calculating hot water When there is a margin, the temperature can be set to a threshold value. When the temperature is lower than a certain value, it is directly set to zero. The value of N1 depends on the product requirements. The lower the power of heating unit 1, the greater the value; the higher the water requirement, the greater the value. When S206 determines yes, it proves that the remaining amount of hot water in the tank is too little or the water temperature is too low. S207 is executed, the auxiliary heating mode. If there is no heating unit 2, the water flow control device 08 is adjusted to the state of circulating heating, and the water flow is driven. Device 06 works with heating unit 05, heats the water in the water tank together with the heat pump, and can control the water temperature of the circulating heating. From the perspective of scale formation and heat pump efficiency, the heating unit heats the water temperature to 28 degrees or 30 degrees. Left and right are more suitable. The temperature can be controlled by adjusting the size of the water flow through the water flow control device 08. Of course, it can also be adjusted by adjusting the power of the heating unit 1. However, generally in order to quickly provide hot water, it is only logical for the heating unit 1 to operate at maximum power. If the structural form of heating unit 2 in Figure 3 is used, heating unit 2 works together with the heat pump. After executing the above actions, the program returns to S201, and so on. The subsequent statements saying "return to S201" also have the same meaning, that is, starting from the beginning. Start executing. In actual products, the program not only has this function, but also has more functional modules. Therefore, in actual products, it is impossible to return to S201 immediately after executing S207. Instead, other program fragments are executed. The whole process goes like this. For electrical products, even if the program is not complex, the serial mode is used. Since the computing speed of the microcontroller is very fast, it only takes more than ten milliseconds to execute all the programs. Such continuous loops appear to people to be happening at the same time. When S206 determines no, it proves that the hot water remaining in the water tank is sufficient, and returns to S201 (in the figure, S217 is executed, which is equivalent to returning to S201).

The above is a control method when it is judged in S205 that the water heater is not supplying water to the outside. When it is judged that the hot water is being supplied to the outside, S208 is executed to compare the temperature t1 of the upper part of the water tank (if there are two sensors installed on the water tank, the one at the top is The sensor temperature shall prevail. Of course, if the temperature in the middle or other positions is used as the criterion, the function can also be realized, and it is also within the scope of protection of this patent, but the energy saving effect is not that good. If the estimation of the hot water reserve is based on a sensor plus When implementing the water flow sensing unit, it is also possible to estimate the current water temperature at the top of the water tank through the calculation method in Embodiment 1, but it is not as accurate as multiple sensors. It is also possible to determine the heating unit directly through the outlet water temperature sensor without performing the judgment of S208. 1. Whether auxiliary heating is needed. In short, there are many control methods. The key lies in the structural form of this patent and the overall idea of controlling according to the hot water margin) whether it is greater than or equal to the outlet water setting temperature t2. If it is judged to be no, it must Heating unit 1 is required to provide auxiliary heat to bring the outlet water up to temperature. If yes, if the heating unit does not provide auxiliary heat to the water outlet, then the amount of water in the water tank must also be considered. When S208 is judged to be negative, S215 is executed. In this statement, it will be judged how much the temperature of the upper part of the water tank is smaller than the water outlet setting temperature, and the working mode of the actuator is determined based on the degree of the temperature. When S208 determines yes, S209 is executed to determine whether the hot water residual Q is greater than N2. The value of N2 examines how much hot water can be provided without using the auxiliary heat of the heating unit. For example, the program can set N2 to 2700 liters, which is equivalent to 45 degrees multiplied by 60 liters. When greater than or equal to this value, the judgment is yes, S210 is executed, and the non-auxiliary heat water supply mode is used. If the heating unit does not work when using hot water, return to S201. If it is less than N2, the judgment is no and S211 is executed. S211 is similar to S209. It determines whether the hot water residual Q is greater than N3. The value of N3 is smaller than N2. For example, it can be set to 2300 liters. When the judgment is yes, execute S212, low-grade auxiliary heat water supply mode. In this mode, the heating unit When the water heater discharges water, only low-level power auxiliary heat is used. This is because the remaining hot water reserve in the water tank is close to the amount that does not require auxiliary heat. Only low-level auxiliary heat is needed to supply water. Return to S201. When S211 is determined to be no, S213 is executed to determine whether the hot water residual Q is greater than N4. The value of N4 is one level lower, for example, it can be set to 1900 liters. When S213 is determined to be yes, S214 is executed to use the mid-range auxiliary In hot water supply mode, the heating unit adopts mid-range heating and returns to S201. When the determination in S213 is negative, S216 is executed to adopt the high-grade auxiliary heat water supply mode. Once the heating unit adopts high-grade heating, return to S201. Then follow S215, which is executed when S208 is judged to be negative. Entering this step, it proves that the water temperature in the upper part of the water tank is lower than the outlet water set temperature, so electric auxiliary heat must be used for heating, but we have to further determine how much lower than the outlet water set temperature. , decide how much power to use for heating. Of course, you can also directly adjust the power of the heating unit through the thyristor according to the outlet water temperature to achieve constant temperature. However, if it is not controlled by the thyristor, but several groups of relays, the temperature change is not Smoothly, and if the water flow control device 08 is used to adjust the water output from the water tank, two variables will appear. In the case of two variables, it is difficult to adjust the constant temperature, and one parameter must be fixed first. In S215, it is judged whether the temperature t1 of the upper part of the water tank is less than the outlet water set temperature t2 minus q1. q1 can be set to a reasonable value according to the actual usage, for example, set to 8. If it is judged to be yes, it proves that the water tank temperature is smaller than the outlet water set temperature. 8 degrees or above, in this case, execute S216, adopt the high-grade auxiliary heat water supply mode, the heating unit adopts high-grade heating, and return to S201. If S215 determines no, it proves that there is not as much as 8 degrees. At this time, S211 is executed to determine how much hot water remains in the water tank, and the same logical judgment as before is entered. Please note that this 8 degrees is also based on practical considerations. For example, the low-end power is 2KW. At 2KW, the water volume is opened to 4 liters and the temperature rises by 7 degrees. Of course, this 8 degrees can also be other values.

The power of the heating unit is divided into high, medium and low above. This is just an example. It can be divided into more sections or not. You can also fix the parameter of water volume first, and use a thyristor to steplessly adjust the power of the heating unit 4 to achieve constant temperature. , but the method of using thyristor has disadvantages. For example, although the water tank temperature is high, the water volume is small. When the product of the water volume times the water temperature is less than n4, high-end heating should be used. Of course, using high-end heating will greatly exceed the set outlet water temperature. Therefore, more cold water should be provided at this time, which prolongs the use time. If thyristor control is used, if the water temperature is high and the water volume is small, the heating unit may use very low power, or may not heat at all. This embodiment only introduces one of the more preferred solutions. Based on this structure and this control method, people in the industry can easily come up with more unique control logics.

The above control method allows the patented heat pump water heater to quickly provide enough hot water at any time, perfectly balancing energy saving and experience, and maximizing the energy saving effect to the extreme, regardless of whether the patented heat pump water heater is used. The technological development of small-power heat pump water heaters is still used in traditional larger-power heat pump water heaters, whether split or integrated, they all have unique advantages.

The above-mentioned embodiments do not exhaust all the structures and methods. The combination of all the above-mentioned solutions and any solution that can be easily imagined through the present invention are within the scope of protection of this patent.

Claims (10)

A heat pump water heater includes a water tank (01), a compressor (02), an evaporator (03), a condenser (04), a throttling device (09), a temperature sensor (12), and a control unit, and is characterized by: It includes a heating unit one (05), a hot water residual sensing unit, a water flow sensing unit (07), and an auxiliary heating device. The heating unit one is installed in such a way that it can heat the water output from the water tank. The auxiliary heating device It is used to auxiliary heat the water in the water tank. The hot water remaining amount sensing unit is used to determine the remaining amount of hot water in the water tank, and controls the heating unit according to the hot water remaining amount, temperature and the signal of the water flow sensing unit. 1. The working status of the auxiliary heating device. A heat pump water heater according to claim 1, characterized in that: the auxiliary heating device includes a water flow driving device (06) and a water flow control device (08), and the water tank, heating unit 1, water flow driving device, and water flow control device The devices are connected together to form an auxiliary heat heating circuit. The water flow driving device drives the water flow through the heating unit to cyclically heat the heat storage medium in the water tank. The water flow driving device can also be used for water outlet pressurization, zero cold water circulation, and automatic cleaning. One or more of the above, the water flow control device is used to limit the direction of the water flow, switch the water flow path, control the ratio of hot and cold water, and control one or more of the flow. A heat pump water heater according to claim 2, characterized in that: it further includes a settling device (10), the settling device is connected in series on the water outlet channel of the heat pump water heater, and the water inlet end of the water flow driving device is connected to the water outlet of the heat pump water heater. At the bottom of the water tank, the settling device is located on the circulation path of the water flow driving device. A heat pump water heater according to claim 2, characterized in that: the water flow control device includes a stepper motor and a valve. A heat pump water heater according to claim 1, characterized in that: the hot water remaining amount sensing unit includes at least two temperature sensors, and the temperature sensors are installed at different water levels of the water tank. According to the different positions of the temperature sensors Measure the temperature of the water tank and calculate the remaining amount of hot water. A heat pump water heater according to claim 1, characterized in that: the hot water residual sensing unit includes the water flow sensing unit and at least one temperature sensor, and the hot water output measured by the data of the temperature sensor and the water flow sensing unit is Estimate the current hot water balance of the water tank based on the working parameters of the auxiliary heating device and heat pump. A heat pump water heater according to claim 1, characterized in that: the auxiliary heating device includes a heating unit 2, and the heating unit 2 is used to heat water in the water tank. A heat pump water heater according to any one of claims 1 to 6, characterized in that: the control unit, the heating unit 1, the water flow sensing unit, the water flow driving device, and the water flow control device are integrated together to form an auxiliary module, and the The auxiliary module can be further integrated with the heat pump component to form a heating module, and cooperates with the heat storage module through the water flow interface, electronic and electrical interface, and fastening device to form a modular structure that is easy to disassemble and assemble. A control method for a heat pump water heater, characterized in that the control method includes the following steps: Step 1. Obtain hot water residual, temperature, and water flow status information; Step 2. Control the working status of the heat pump, heating unit 1 and auxiliary heating device based on the above information. A control method for a heat pump water heater according to claim 9, the control method further comprising: Step 1. Compare the hot water temperature t at the bottom of the water tank with the water tank set temperature t0. If it is lower than the water tank set temperature, the heat pump starts. Otherwise, the heat pump stops. Go to step 2; Step 2. Obtain the available hot water balance Q in the water tank; Step 3. Is the outlet water flow sensing unit started? If not, go to step 4; if yes, go to step 6; Step 4. Is the residual amount of hot water Q in the water tank less than N1? If yes, go to step 5; if not, return to step 1; Step 5: Execute the auxiliary heating mode and return to step 1; Step 6. Compare whether the temperature t1 of the upper part of the water tank is greater than or equal to the outlet water setting temperature t2? If yes, go to step 7; if not, go to step 14; Step 7. Is the residual amount of hot water Q in the water tank greater than N2? If yes, go to step 13; if not, go to step 8; Step 8. Is the residual amount of hot water Q in the water tank greater than N3? If yes, go to step 12; if not, go to step 9; Step 9. Is the residual amount of hot water Q in the water tank greater than N4? If yes, go to step 11; if not, go to step 10; Step 10. High-grade auxiliary heat water supply mode, return to step 1; Step 11. Mid-range auxiliary heat water supply mode, return to step 1; Step 12. Low-grade auxiliary heat water supply mode, return to step 1; Step 13. If there is no auxiliary heat water supply mode, return to step 1; Step 14. Compare whether the temperature t1 of the upper part of the water tank is less than the outlet water set temperature t2-q1. If yes, go to step 10. If not, go to step 8.