A control method, a control device and a solar heat pump system for a state of fluorine deficiency

Abstract

An embodiment of the present invention discloses a control method, a control device and a solar heat pump system for protecting the fluorine-deficient state during the operation of the refrigerant compressor in the solar heat pump system. By only monitoring three temperatures, namely the ambient temperature, the water temperature and the exhaust gas temperature, the fluorine-containing state of the solar heat pump system is determined, and then according to the fluorine-containing state, the purpose of automatically controlling the working state of the refrigerant compressor is achieved. This method only collects the ambient temperature Th, the water temperature Ts and the exhaust gas temperature Tp, avoiding the influence of sunlight, which is beneficial to the evaluation of the fluorine-containing state of the solar heat pump system and better protects the solar heat pump water heater from fluorine deficiency.

Description

Technical Field

[0001] Embodiments of the present invention relate to the technical field of air source heat pumps, and in particular to a control method for a fluorine-deficient state, a control device, and a solar heat pump system. Background Art

[0002] The fluorine-deficient fault in the market is one of the most common faults in all heat pump systems. The differences in the operation levels of installers and the minor leaks at each connection part over the years will all lead to fluorine-deficient faults. Once a fluorine-deficient fault occurs, the effect of the heat pump system will be greatly reduced, mainly manifested as an extremely slow heating speed, and in severe cases, it will even cause irreversible damage to the compressor, greatly affecting the user experience.

[0003] During a fluorine-deficient fault, the exhaust temperature will increase significantly, and the heat exchange temperature difference between the low-pressure side and the high-pressure side will decrease significantly. In response to this, current pure heat pump products have given corresponding fluorine-deficient protection solutions. The fluorine-deficient protection solution is that when the difference between the ambient temperature and the suction temperature / evaporation temperature and the difference between the exhaust temperature and the water temperature both reach the first preset value and the second preset value, the fluorine-deficient protection is triggered, the display panel displays a fluorine-deficient code, and the water heater is controlled to stop running. The current fluorine-deficient protection solution can well solve pure heat pump products, but it is not applicable to solar heat pump products.

[0004] Because a large part of the energy source of the low-pressure side of solar heat pump products is solar energy, in normal operation, when the weather is good and the sunlight is sufficient, the difference between the ambient temperature and the suction temperature / evaporation temperature will be very small, or even negative. When the weather is bad and the sunlight is poor, the difference between the ambient temperature and the suction temperature / evaporation temperature will be very large. This will cause this difference to be uncertain. Therefore, the fluorine-deficient protection solution required for solar heat pumps must exclude the parameter values that are easily affected by sunlight, so the suction temperature and evaporation temperature cannot be considered in the solution. Summary of the Invention

[0005] In view of this, the control method for a fluorine-deficient state, the control device, and the solar heat pump system provided by the embodiments of the present invention determine the fluorine-containing state of the solar heat pump system by monitoring these three temperatures: the ambient temperature, the water temperature, and the exhaust temperature, and determine the fluorine-containing state to achieve the purpose of automatically controlling the working state of the refrigerant compressor, avoiding the influence of sunlight, being beneficial to the evaluation of the fluorine-containing state of the solar heat pump system, and better protecting the solar heat pump water heater from fluorine deficiency.

[0006] In a first aspect, an embodiment of the present invention provides a control method for a fluorine-deficient state, which is applied to the protection of the fluorine-deficient state when the refrigerant compressor of a solar heat pump system is working. The control method includes:

[0007] Obtain the ambient temperature outside, the water temperature in the solar water storage tank, and the exhaust temperature at the exhaust hole of the refrigerant compressor;

[0008] Determine the fluorine-containing state of the solar heat pump system according to the ambient temperature, the water temperature, and the exhaust temperature; the fluorine-containing state includes a fluorine-deficient state.

[0009] Control the operating state of the refrigerant compressor according to the fluorine-containing state; the operating state includes shutdown and startup.

[0010] Optionally, a preset ambient temperature, a preset water temperature, and an alarm exhaust temperature are pre-stored in the solar heat pump system.

[0011] Determining the fluorine-containing state of the solar heat pump system according to the ambient temperature, the water temperature, and the exhaust temperature includes:

[0012] Determine the fluorine-containing state of the solar heat pump system according to the comparison result between the ambient temperature and the preset ambient temperature, the comparison result between the water temperature and the preset water temperature, and the comparison result between the exhaust temperature and the alarm exhaust temperature.

[0013] Optionally, before determining the fluorine-containing state of the solar heat pump system according to the ambient temperature, the water temperature, and the exhaust temperature, it further includes:

[0014] Establish a corresponding relationship between a preset temperature range, a preset water temperature, and an alarm exhaust temperature.

[0015] Optionally, the preset ambient temperature includes a first preset temperature range, a second preset temperature range, a third preset temperature range, and a fourth preset temperature range, and the temperatures of the first preset temperature range, the second preset temperature range, the third preset temperature range, and the fourth preset temperature range increase in sequence; the preset water temperature includes a first preset water temperature, a second preset water temperature, a third preset water temperature, and a fourth preset water temperature that increase in sequence, and the alarm exhaust temperature includes an alarm exhaust temperature.

[0016] Establishing a corresponding relationship between a preset temperature range, a preset water temperature, and an alarm exhaust temperature includes:

[0017] Obtain a first alarm exhaust temperature corresponding to the first preset temperature range and the first preset water temperature according to the pressure-enthalpy diagram of the refrigerant, and establish a corresponding relationship between the first preset temperature range, the first preset water temperature, and the alarm exhaust temperature.

[0018] Obtain a second alarm exhaust temperature corresponding to the second preset temperature range and the second preset water temperature according to the pressure-enthalpy diagram of the refrigerant, and establish a corresponding relationship between the second preset temperature range, the second preset water temperature, and the alarm exhaust temperature.

[0019] Obtain the third alarm exhaust temperature corresponding to the third preset temperature range and the third preset water temperature according to the pressure-enthalpy diagram of the refrigerant, and establish the corresponding relationship among the third preset temperature range, the third preset water temperature, and the alarm exhaust temperature;

[0020] Obtain the fourth alarm exhaust temperature corresponding to the fourth preset temperature range and the fourth preset water temperature according to the pressure-enthalpy diagram of the refrigerant, and establish the corresponding relationship among the fourth preset temperature range, the fourth preset water temperature, and the alarm exhaust temperature.

[0021] Optionally, determining the fluorine-containing state of the solar heat pump system according to the environmental temperature, the water temperature, and the exhaust temperature includes:

[0022] Judge whether the current environmental temperature is within any one of the first preset temperature range, the second preset temperature range, the third preset temperature range, and the fourth preset temperature range;

[0023] If the current environmental temperature is within any one of the first preset temperature range, the second preset temperature range, the third preset temperature range, and the fourth preset temperature range;

[0024] According to the corresponding relationship among the preset temperature range, the preset water temperature, and the alarm exhaust temperature, and according to the preset temperature range where the environmental temperature is located and the preset water temperature corresponding to this preset temperature range, judge whether the current water temperature is less than or equal to the preset water temperature;

[0025] If the water temperature is less than or equal to the preset water temperature, judge whether the exhaust temperature is greater than the alarm exhaust temperature;

[0026] If the exhaust temperature is greater than the alarm exhaust temperature, determine that the fluorine-containing state of the solar heat pump system is a fluorine-deficient state.

[0027] Optionally, the solar heat pump system includes a fluorine-deficiency alarm,

[0028] After determining that the fluorine-containing state of the solar heat pump system is a fluorine-deficient state, it further includes:

[0029] Start the fluorine-deficiency alarm, and the fluorine-deficiency alarm is used for fluorine-deficiency alarm display.

[0030] Optionally, controlling the working state of the refrigerant compressor according to the fluorine-containing state includes:

[0031] According to the fluorine-containing state of the solar heat pump system being a fluorine-deficient state, control the working state of the refrigerant compressor to stop and start alternately for a preset number of times.

[0032] Optionally, the fluorine-containing state further includes a normal fluorine state.

[0033] Controlling the operating state of the refrigerant compressor according to the fluorine-containing state includes:

[0034] Controlling the refrigerant compressor to operate normally according to the normal fluorine state.

[0035] In a second aspect, an embodiment of the present invention further provides a control device for a fluorine-deficient state. The control device includes:

[0036] A temperature acquisition module for acquiring the ambient temperature, the water temperature in the solar energy storage water tank, and the exhaust temperature of the refrigerant compressor exhaust port.

[0037] A fluorine-containing state determination module for determining the fluorine-containing state of the solar heat pump system according to the ambient temperature, the water temperature, and the exhaust temperature; the fluorine-containing state includes a fluorine-deficient state.

[0038] A control module for controlling the operating state of the refrigerant compressor according to the fluorine-containing state; the operating state includes shutdown and startup.

[0039] In a third aspect, the present invention further provides a solar heat pump system. The solar heat pump system includes a microprocessor, and the microprocessor is used to execute the control method provided in the first aspect.

[0040] The control method for the fluorine-deficient state provided by the embodiment of the present invention is applied to the protection of the fluorine-deficient state during the operation of the refrigerant compressor in the solar heat pump system. Only by monitoring three temperatures, namely the ambient temperature, the water temperature, and the exhaust temperature, the fluorine-containing state of the solar heat pump system is determined, and then according to the fluorine-containing state, the purpose of automatically controlling the operating state of the refrigerant compressor is achieved. This method only collects the ambient temperature Th, the water temperature Ts, and the exhaust temperature Tp, avoiding the influence of sunlight, which is beneficial to the evaluation of the fluorine-containing state of the solar heat pump system and better protects the solar heat pump water heater from fluorine deficiency. Description of the Drawings

[0041] By reading the detailed description of the non-limiting embodiments with reference to the following drawings, other features, objects, and advantages of the present invention will become more obvious:

[0042] Figure 1 It is a schematic flow chart of a control method for a fluorine-deficient state provided by the present invention;

[0043] Figure 2 It is a schematic flow chart of another control method for a fluorine-deficient state provided by the present invention;

[0044] Figure 3 It is an enthalpy-pressure diagram of R22 refrigerant provided by the embodiment of the present invention.

[0045] Figure 4 It is a schematic flow chart of another method for controlling the state of lack of fluorine provided by the present invention;

[0046] Figure 5 It is a schematic flow chart of another method for controlling the state of lack of fluorine provided by the present invention;

[0047] Figure 6 It is a control logic flow chart of the state of lack of fluorine provided by an embodiment of the present invention;

[0048] Figure 7 It is a control logic flow chart of the state of lack of fluorine provided by an embodiment of the present invention;

[0049] Figure 8 It is a schematic diagram of a control device for the state of lack of fluorine provided by an embodiment of the present invention. Detailed implementation manners

[0050] To make the objectives, technical solutions and advantages of the present invention clearer, the following will, in combination with the accompanying drawings in the embodiments of the present invention, completely describe the technical solutions of the present invention through specific implementation manners. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0051] Embodiment

[0052] An embodiment of the present invention provides a method for controlling the state of lack of fluorine, which can be applied to the protection of the state of lack of fluorine when the refrigerant compressor in a solar heat pump system is working. The solar heat pump system includes a microprocessor, and a preset program is built in the microprocessor, which can execute the method for controlling the state of lack of fluorine provided by the embodiment of the present invention. When the refrigerant compressor in the solar heat pump system lacks fluorine during the working process, the refrigerant compressor can be protected.

[0053] Figure 1 It is a schematic flow chart of a method for controlling the state of lack of fluorine provided by the present invention. As Figure 1 shown, the method for controlling the state of lack of fluorine provided by the embodiment of the present invention includes:

[0054] S101. Obtain the external ambient temperature, the water temperature in the solar water storage tank, and the exhaust temperature of the exhaust hole of the refrigerant compressor.

[0055] Specifically, the solar heat pump system further includes an ambient temperature sensor, a water temperature sensor, and an exhaust gas temperature sensor. When the solar heat pump system operates, the ambient temperature sensor monitors the ambient temperature Th outside the solar heat pump system and transmits the ambient temperature Th to the microprocessor; the water temperature sensor monitors the water temperature Ts in the water tank of the solar heat pump system and transmits the water temperature Ts to the microprocessor; the exhaust gas temperature sensor monitors the exhaust gas temperature Tp at the exhaust port of the refrigerant compressor and transmits the exhaust gas temperature Tp to the microprocessor.

[0056] S102. Determine the fluorine-containing state of the solar heat pump system according to the ambient temperature, water temperature, and exhaust gas temperature.

[0057] Specifically, the fluorine-containing state includes a fluorine-deficient state. The microprocessor determines the fluorine-containing state of the solar heat pump system according to the numerical values of the received ambient temperature Th, water temperature Ts, and exhaust gas temperature Tp. For example, when the numerical relationship of the ambient temperature Th, water temperature Ts, and exhaust gas temperature Tp satisfies a preset condition, it is determined that the solar heat pump system is in a fluorine-deficient state under this operating state.

[0058] S103. Control the operating state of the refrigerant compressor according to the fluorine-containing state.

[0059] Specifically, the operating state includes shutdown and startup. When the microprocessor determines that the solar heat pump system is in a fluorine-deficient state, it automatically controls the refrigerant compressor to shut down, which plays a role in protecting the refrigerant compressor, reducing irreversible damage to the compressor, extending the service life, and improving the user experience.

[0060] In summary, the control method for the fluorine-deficient state provided by the embodiment of the present invention is applied to the protection of the fluorine-deficient state when the refrigerant compressor of the solar heat pump system operates. Only by monitoring the three temperatures of the ambient temperature, water temperature, and exhaust gas temperature, the fluorine-containing state of the solar heat pump system is determined, and then according to the fluorine-containing state, the purpose of automatically controlling the operating state of the refrigerant compressor is achieved. This method only collects the ambient temperature Th, water temperature Ts, and exhaust gas temperature Tp, avoiding the influence of sunlight, which is beneficial to the evaluation of the fluorine-containing state of the solar heat pump system and better protects the solar heat pump water heater from fluorine deficiency.

[0061] Figure 2 is a schematic flowchart of another control method for the fluorine-deficient state provided by the present invention. As Figure 2 shown, optionally, the solar heat pump system pre-stores a preset ambient temperature Th0, a preset water temperature Ts0, and an alarm exhaust gas temperature Tp0;

[0062] S201. Obtain the ambient temperature outside, the water temperature in the solar storage water tank, and the exhaust gas temperature at the exhaust port of the refrigerant compressor.

[0063] Combined with Figure 1 and Figure 2 shown.

[0064] S202. Determine the fluorine-containing state of the solar heat pump system according to the comparison results of the ambient temperature and the preset ambient temperature, the water temperature and the preset water temperature, and the exhaust gas temperature and the alarm exhaust gas temperature.

[0065] Specifically, the fluorine-containing state includes a fluorine-deficient state. The microprocessor respectively compares the received ambient temperature Th with the value of the preset ambient temperature Th0, the water temperature Ts with the value of the preset water temperature Ts0, and the exhaust gas temperature Tp with the value of the alarm exhaust gas temperature Tp0 according to the comparison program preset in the system to determine the fluorine-containing state of the solar heat pump system. For example, when the value of the ambient temperature Th is greater than the value of the preset ambient temperature Th0, the value of the water temperature Ts is greater than the value of the preset water temperature Ts0, and the value of the exhaust gas temperature Tp is greater than the value of the alarm exhaust gas temperature Tp0, it is determined that the solar heat pump system is in a fluorine-deficient state in this working state; or, when the value of the ambient temperature Th is greater than the value of the preset ambient temperature Th0, the value of the water temperature Ts is less than the value of the preset water temperature Ts0, and the value of the exhaust gas temperature Tp is greater than the value of the alarm exhaust gas temperature Tp0, it is determined that the solar heat pump system is in a fluorine-deficient state in this working state.

[0066] S203. Control the working state of the refrigerant compressor according to the fluorine-containing state.

[0067] Continue to refer to Figure 1 as shown.

[0068] Based on the above embodiments, continue to refer to Figure 2 as shown. Before step S202, it further includes:

[0069] S204. Establish the corresponding relationship between the preset temperature range, the preset water temperature, and the alarm exhaust gas temperature.

[0070] Currently, there are many types of refrigerants on the market, such as R22 refrigerant, R134a refrigerant, R342 refrigerant, etc. Figure 3 This is the pressure-enthalpy diagram of an R22 refrigerant provided by the present invention. Among them, the pressure-enthalpy diagram refers to the curve diagram of pressure and enthalpy value, which is often used for refrigerant analysis. The ordinate of this diagram is the natural logarithm of the absolute pressure lnp (the value represented is the absolute value of the pressure), and the abscissa is the specific enthalpy value h. Combine Figure 3As shown in the figure, taking a solar energy heat pump water heater using R22 refrigerant as an example, the embodiment of the present invention can calculate a preset temperature range Th0, a preset water temperature Ts0, and an alarm exhaust temperature Tp0 that can be used in the fluorine-deficient state of the solar energy heat pump water heater based on the pressure-enthalpy diagram of the R22 refrigerant, and establish a corresponding relationship. The alarm exhaust temperature Tp0 can be referred to as the theoretical maximum exhaust temperature. It can be understood that when the exhaust temperature Tp of the R22 refrigerant compressor is higher than the alarm exhaust temperature Tp0 in this operating state, the R22 refrigerant compressor is fluorine-deficient, that is, the solar energy heat pump water heater is in a fluorine-deficient state.

[0071] Specifically, according to the working temperature of the solar energy heat pump water heater, the ambient temperature can be divided into 4 intervals, and correspondingly the water temperature can be divided into 4 intervals. The preset ambient temperature Th0 includes a first preset temperature range Th1, a second preset temperature range Th2, a third preset temperature range Th3, and a fourth preset temperature range Th4. The temperatures of the first preset temperature range Th1, the second preset temperature range Th2, the third preset temperature range Th3, and the fourth preset temperature range Th4 increase in sequence; the preset water temperature Ts0 includes a first preset water temperature Ts1, a second preset water temperature Ts2, a third preset water temperature Ts3, and a fourth preset water temperature Ts4 that increase in sequence.

[0072] Figure 4 It is a flowchart showing another control method for the fluorine-deficient state provided by the present invention. On the basis of the above embodiment, as Figure 4 shown, step S204 includes:

[0073] S2041. Obtain the alarm exhaust temperature corresponding to the first preset temperature range and the first preset water temperature according to the pressure-enthalpy diagram of the refrigerant, and establish the corresponding relationship among the first preset temperature range, the first preset water temperature, and the alarm exhaust temperature.

[0074] Specifically, according to the common knowledge in the industry: the higher the condensation pressure of a solar heat pump water heater, the higher the condensation temperature; the lower the evaporation pressure, the lower the evaporation temperature; the evaporation temperature and the ambient temperature are in the relationship of the cold source temperature and the heat source temperature of a heat transfer system, and the condensation temperature and the water temperature are the same. The condensation temperature is the heat source temperature, and the water temperature is the cold source temperature, and a heat cycle is formed between the cold source and the heat source. Further, based on the actual tests and calculations, it can be known that: the larger the ratio of the condensation pressure to the evaporation pressure, the higher the suction superheat degree, and the higher its exhaust temperature; based on the temperature difference between the cold source temperature and the heat source temperature of the solar heat pump system, which is generally between 5°C and 15°C, the suction superheat degree is generally between 0 and 15°C. Usually, the working ambient temperature of a solar heat pump water heater is between -7°C and 43°C. For example, taking the ambient temperature of the solar heat pump water heater as Th1 = 35°C and the water temperature Ts1 = 40°C as a reference, the evaporation temperature T1 of the R22 refrigerant is set to be T1 = Th1 - 15° = 20°C, where the temperature difference value takes the maximum value of 15°C; the condensation temperature T2 = Ts1 + 15° = 55°C, where the suction superheat degree takes the maximum value of 15°C; the suction temperature T3 = 35°C. Combining Figure 3 with the medium-pressure enthalpy diagram, the theoretical maximum exhaust temperature under this working condition is calculated using the reverse Carnot cycle principle.

[0075] Based on the evaporation temperature T1 = 20°C, the condensation temperature T2 = 55°C, and the suction temperature T3 = 35°C, according to the 55°C isothermal line and the 20°C isothermal line, find Figure 3 the exhaust state point A of the reverse Carnot cycle and the suction state point B of the reverse Carnot cycle. From Figure 3 it can be known that the enthalpy value corresponding to the abscissa of point A is 450 kj / kg, and the enthalpy value corresponding to the abscissa of point B is 420 kj / kg.

[0076] The enthalpy difference in the compression process under the reverse Carnot cycle is calculated as: 450 - 420 = 30 kj / kg;

[0077] According to the experimental tests and calculations, it can be known that the isentropic efficiency of a rotary compressor is usually between 0.75 and 0.9. Here, the lowest value of 0.75 is taken, and the enthalpy difference in the actual compression process is calculated as: 30 / 0.75 = 40 kj / kg;

[0078] The enthalpy value corresponding to the actual exhaust state point should be calculated as: 40 + 420 = 460 kj / kg;

[0079] Then, according to Figure 3 the pressure value corresponding to the 55°C isothermal condensation temperature and the enthalpy value of 460 kj / kg, it can be obtained in Figure 3The actual exhaust state point C of the reverse Carnot cycle is found in the [relevant content], and the corresponding exhaust temperature value is 93 °C. Therefore, based on the pressure-enthalpy diagram of R22 refrigerant, when the first preset temperature range Th1 ≥ 35 °C and the first preset water temperature Ts1 ≤ 40 °C, the theoretical maximum exhaust temperature is 93 °C, that is, the alarm exhaust temperature Tp0 is 93 °C, and the corresponding relationship shown in Table 1 is established.

[0080] Since the most extreme cases have been considered in Table 1, during the normal operation of the solar heat pump water heater, when the environmental temperature range and water temperature conditions in item 1 of Table 1 are met and the system is in a non-fluorine-deficient state, the exhaust temperature will not exceed the theoretical maximum exhaust temperature of 93 °C. That is, when the R22 refrigerant solar heat pump product is operating normally, when the environmental temperature is 35 °C and the water temperature is 40 °C, the exhaust temperature will not exceed 93 °C.

[0081] When a fluorine-deficiency fault occurs in the system, the exhaust temperature will increase significantly. Considering the temperature acquisition error and system fluctuations, a margin is usually left, and the calculated theoretical maximum exhaust temperature of 93 °C is increased to 100 °C to avoid the possibility of misjudgment. That is, in practical applications, when the microprocessor of the solar heat pump system determines that the environmental temperature in this operating state ≥ 35 °C and the water temperature in the storage tank ≤ 40 °C, and the exhaust temperature at this time > 100 °C, it is determined that the system is in a fluorine-deficient state.

[0082] Table 1 shows the corresponding relationship between the preset temperature range, preset water temperature, and alarm exhaust temperature calculated based on the pressure-enthalpy diagram of R22 refrigerant

[0083]

[0084] S2042. Obtain the alarm exhaust temperature corresponding to the second preset temperature range and the second preset water temperature according to the pressure-enthalpy diagram of the refrigerant, and establish the corresponding relationship between the second preset temperature range, the second preset water temperature, and the alarm exhaust temperature.

[0085] Specifically, using the calculation method provided in the above embodiment, combined with Figure 3 the pressure-enthalpy diagram of R22 refrigerant shown, it is deduced that the second preset temperature range is 20 °C ≤ Th2 < 35 °C, the second preset water temperature Ts2 ≤ 30 °C, and its theoretical maximum exhaust temperature is 91 °C, that is, the alarm exhaust temperature is 91 °C, and the corresponding relationship shown in Table 1 is established.

[0086] Similarly, when a refrigerant shortage fault occurs in the system, the exhaust temperature will increase significantly. Considering the temperature acquisition error and system fluctuations, a margin is usually reserved. The theoretically maximum exhaust temperature of 91 °C derived from the calculation is increased to 100 °C to avoid the possibility of misjudgment. That is, in practical applications, when the microprocessor of the solar heat pump system determines that the ambient temperature at this operating state is 20 °C ≤ Th2 < 35 °C and the water temperature Ts2 ≤ 30 °C, and the exhaust temperature at this time > 100 °C, it is determined that the system is in a refrigerant shortage state.

[0087] S2043. Obtain the alarm exhaust temperature corresponding to the third preset temperature range and the third preset water temperature according to the pressure-enthalpy diagram of the refrigerant, and establish the corresponding relationship among the third preset temperature range, the third preset water temperature, and the alarm exhaust temperature.

[0088] Specifically, using the calculation method provided in the above embodiment, combined with Figure 3 the pressure-enthalpy diagram of R22 refrigerant shown in the figure, it is deduced that the third preset temperature range is 5 °C ≤ Th3 < 20 °C, the third preset water temperature Ts3 ≤ 20 °C, and its theoretically maximum exhaust temperature is 90 °C, that is, the alarm exhaust temperature is 90 °C, and the corresponding relationship shown in Table 1 is established.

[0089] Similarly, when a refrigerant shortage fault occurs in the system, the exhaust temperature will increase significantly. Considering the temperature acquisition error and system fluctuations, a margin is usually reserved. The theoretically maximum exhaust temperature of 90 °C derived from the calculation is increased to 100 °C to avoid the possibility of misjudgment. That is, in practical applications, when the microprocessor of the solar heat pump system determines that the ambient temperature at this operating state is 5 °C ≤ Th3 < 20 °C and the water temperature Ts3 ≤ 20 °C, and the exhaust temperature at this time > 100 °C, it is determined that the system is in a refrigerant shortage state.

[0090] S2044. Obtain the fourth alarm exhaust temperature corresponding to the fourth preset temperature range and the fourth preset water temperature according to the pressure-enthalpy diagram of the refrigerant, and establish the corresponding relationship among the fourth preset temperature range, the fourth preset water temperature, and the alarm exhaust temperature.

[0091] Specifically, using the calculation method provided in the above embodiment, combined with Figure 3 the pressure-enthalpy diagram of R22 refrigerant shown in the figure, it is deduced that the fourth preset temperature range is -7 °C ≤ Th4 < 5 °C, the third preset water temperature Ts4 ≤ 15 °C, and its theoretically maximum exhaust temperature is 96 °C, that is, the alarm exhaust temperature is 96 °C, and the corresponding relationship shown in Table 1 is established.

[0092] Similarly, when a refrigerant shortage fault occurs in the system, the exhaust temperature will increase significantly. Considering the error in temperature acquisition and the system fluctuations, a margin is usually left, and the theoretically maximum exhaust temperature of 96°C derived through calculation is increased to 100°C to avoid the possibility of misjudgment. That is, in practical applications, when the microprocessor of the solar heat pump system determines that the ambient temperature in this operating state satisfies -7°C ≤ Th4 < 5°C and the water temperature Ts4 ≤ 15°C, and the exhaust temperature at this time > 100°C, then it is determined that the system is in a refrigerant shortage state.

[0093] It should be noted that those skilled in the art can easily derive the refrigerant shortage state solutions for other refrigerants according to the embodiments of the present invention. Therefore, all the protections for refrigerant shortages using the control method for the refrigerant shortage state provided by the embodiments of the present invention are within the protection scope of this patent.

[0094] Figure 5 is a schematic flowchart of another control method for the refrigerant shortage state provided by the present invention; Figure 6 is a control logic flowchart for the refrigerant shortage state provided by an embodiment of the present invention. Based on the above embodiments, in combination with Figure 5 and Figure 6 as shown, another control method for the refrigerant shortage state provided by the embodiments of the present invention includes:

[0095] S310. Obtain the ambient temperature outside, the water temperature in the solar water storage tank, and the exhaust temperature at the exhaust hole of the refrigerant compressor.

[0096] In combination with Figure 1 and Figure 5 as shown.

[0097] S301. Determine whether the current ambient temperature is within any one of the first preset temperature range, the second preset temperature range, the third preset temperature range, and the fourth preset temperature range; if the current ambient temperature is within any one of the first preset temperature range, the second preset temperature range, the third preset temperature range, and the fourth preset temperature range.

[0098] In combination with Figure 6 as shown.

[0099] S302. According to the corresponding relationship between the preset temperature range, the preset water temperature, and the alarm exhaust temperature, and according to the preset temperature range where the ambient temperature is located and the preset water temperature corresponding to this preset temperature range, determine whether the current water temperature is less than or equal to the preset water temperature.

[0100] In combination with Figure 6 as shown.

[0101] S303. If the water temperature is less than or equal to the preset water temperature, determine whether the exhaust temperature is greater than the alarm exhaust temperature; if the exhaust temperature is greater than the alarm exhaust temperature, determine that the fluorine-containing state of the solar heat pump system is a fluorine-deficient state.

[0102] Specifically, when the refrigerant compressor of the solar heat pump system is operating normally, the ambient temperature sensor monitors the ambient temperature Th outside the solar heat pump system and transmits the ambient temperature Th to the microprocessor, and the water temperature sensor monitors the water temperature Ts in the water tank of the solar heat pump system and transmits the water temperature Ts to the microprocessor; the exhaust temperature sensor monitors the exhaust temperature Tp at the exhaust port of the refrigerant compressor and transmits the exhaust temperature Tp to the microprocessor. Combined with Figure 6 as shown in Table 1, the microprocessor sequentially executes the following steps according to the preset program:

[0103] S3011. If Th1≥35°C is satisfied, then the current ambient temperature Th is within the first preset temperature range Th1, and step S3021 is executed; otherwise, step S3012 is executed.

[0104] S3021. If Ts1≤40°C is satisfied, then the current water temperature Ts in the storage water tank is within the first preset water temperature Ts1, and step S3031 is executed; otherwise, step S300 is executed, that is, control the R22 refrigerant compressor to operate normally.

[0105] S3012. If 20°C≤Th2<35°C is satisfied, then the current ambient temperature Th is within the second preset temperature range Th2, and step S3022 is executed; otherwise, step S3013 is executed.

[0106] S3022. If Ts2≤30°C is satisfied, then the current water temperature Ts in the storage water tank is within the second preset water temperature Ts2, and step S303 is executed; otherwise, step S300 is executed, that is, control the R22 refrigerant compressor to operate normally.

[0107] S3013. If 5°C≤Th3<20°C is satisfied, then the current ambient temperature Th is within the third preset temperature range Th3, and step S3023 is executed; otherwise, step S3014 is executed.

[0108] S3023. If Ts3≤20°C is satisfied, then the current water temperature Ts in the storage water tank is within the third preset water temperature TS3, and step S3031 is executed; otherwise, step S300 is executed, that is, control the R22 refrigerant compressor to operate normally.

[0109] S3014. If -7°C≤Th4<5°C is satisfied, then the current ambient temperature Th is within the fourth preset temperature range Th4, and step S3024 is executed; otherwise, step S300 is executed, that is, control the R22 refrigerant compressor to operate normally.

[0110] S3024. If Ts4 ≤ 15°C is satisfied, the water temperature Ts in the current water storage tank is within the fourth preset water temperature Ts4, and step S3031 is executed; otherwise, step S300 is executed, that is, the R22 refrigerant compressor is controlled to operate normally.

[0111] S3031. If Tp ≥ 100°C, the exhaust temperature of the exhaust hole of the current R22 refrigerant compressor is greater than or equal to the alarm exhaust temperature, it is determined that the fluorine-containing state of the solar heat pump system is a fluorine-deficient state, and step S3041 is executed.

[0112] S3041. Control the refrigerant compressor to stop.

[0113] S300. According to the normal fluorine state, control the refrigerant compressor to operate normally.

[0114] On the basis of the above embodiments, the fluorine-containing state further includes the normal fluorine state. When the microprocessor sequentially executes S3021, S3022, S3023, S3014, and S3024, and determines that the fluorine-containing state of the solar heat pump system is the normal state, control the R22 refrigerant compressor to operate normally.

[0115] On the basis of the above embodiments, in combination with Figure 5 As shown, optionally, after step S303, the control method further includes:

[0116] S304. According to the fluorine-deficient state of the solar heat pump system, control the working state of the refrigerant compressor to stop and start alternately for a preset number of times.

[0117] Specifically, when the microprocessor determines that the fluorine-containing state of the solar heat pump system is a fluorine-deficient state, in order to reduce the damage of the refrigerant compressor, immediately control the refrigerant compressor to work according to the preset number of times of stopping and starting alternately. For example, immediately control the refrigerant compressor to stop for 30 minutes and start for 10 minutes, and repeat the operation 3 times and then stop starting the compressor, so as to achieve the purpose of protecting the refrigerant compressor. The requirement of repeating the stop and start 3 times is considered when the user uses a large amount of water and the water temperature drops significantly in a short time, so as to avoid the possibility of the exhaust temperature not dropping and affecting the performance of the refrigerant compressor. It should be noted that the preset number of times of stopping and starting alternately can be flexibly set according to different refrigerant solar heat pump systems, and no specific limitation is made here.

[0118] On the basis of the above embodiments, in combination with Figure 5 and Figure 6 As shown, optionally, after steps S304 and S3041, the control method further includes:

[0119] S305. Start the fluorine-deficient alarm, and the fluorine-deficient alarm is used for fluorine-deficient alarm display.

[0120] Optionally, the solar heat pump system includes a refrigerant shortage alarm. When the microprocessor determines that the fluorine-containing state of the solar heat pump system is a fluorine shortage state, the refrigerant shortage alarm can be activated at the same time. The refrigerant shortage alarm is set in the display panel of the solar heat pump system to alarm for the fluorine shortage fault. For example, the fluorine shortage fault alarm is carried out in the form of a warning light, a warning sound, warning prompt words, etc., so that the solar heat pump system is in an alarm standby state.

[0121] Figure 7 is another control logic flowchart for the fluorine shortage state provided by the embodiment of the present invention. Combining Figure 7 As shown, the embodiment of the present invention also provides a control method for the fluorine shortage state of R134 refrigerant, which can be applied to the fluorine shortage protection of the R134 refrigerant solar heat pump system. On the basis of the above embodiment, when the refrigerant compressor of the solar heat pump system is running normally, the ambient temperature sensor monitors the ambient temperature Th outside the solar heat pump system and transmits the ambient temperature Th to the microprocessor, and the water temperature sensor monitors the water temperature Ts in the water tank of the solar heat pump system and transmits the water temperature Ts to the microprocessor; the exhaust temperature sensor monitors the exhaust temperature Tp of the exhaust hole of the refrigerant compressor and transmits the exhaust temperature Tp to the microprocessor. Combining Figure 7 As shown, the microprocessor sequentially executes the following steps according to the preset program:

[0122] S4011: If Th≥10°C is satisfied, step S4021 is executed; otherwise, step S4012 is executed.

[0123] S4021: If Ts≤40°C is satisfied, step S4031 is executed; otherwise, step S400 is executed, that is, the R134 refrigerant compressor is controlled to run normally.

[0124] S4012: If -7°C≤Th<10°C is satisfied, step S4022 is executed; otherwise, step S400 is executed, that is, the R134 refrigerant compressor is controlled to run normally.

[0125] S4022: If Ts≤30°C is satisfied, step S403 is executed; otherwise, step S400 is executed, that is, the R134 refrigerant compressor is controlled to run normally.

[0126] S4031: If Tp≥100°C, the exhaust temperature of the exhaust hole of the current R134 refrigerant compressor is higher than the alarm exhaust temperature, it is determined that the fluorine-containing state of the solar heat pump system is a fluorine shortage state, and step S404 is executed.

[0127] S404: According to the fluorine shortage state of the solar heat pump system, the working state of the refrigerant compressor is controlled to stop and start alternately for a preset number of times.

[0128] Continue to refer to Figure 5 - Figure 6 As shown.

[0129] S305. Start the refrigerant shortage alarm, which is used for displaying refrigerant shortage alarms.

[0130] Continue to refer to Figure 5 - Figure 6 as shown.

[0131] Based on the same inventive concept, an embodiment of the present invention further provides a control device for the refrigerant shortage state, which can execute the control method for the refrigerant shortage state provided by the embodiment of the present invention. The control device for the refrigerant shortage state can be composed of software and / or hardware, and the control device for the refrigerant shortage state can be integrated into the microprocessor of the solar heat pump system. Figure 8 is a schematic diagram of a control device for the refrigerant shortage state provided by an embodiment of the present invention. As Figure 8 shown, the control device for the refrigerant shortage state provided by the embodiment of the present invention includes:

[0132] A temperature acquisition module 11, which is used to acquire the ambient temperature outside, the water temperature in the solar water storage tank, and the exhaust temperature of the refrigerant compressor exhaust port.

[0133] A fluorine-containing state determination module 12, which is used to determine the fluorine-containing state of the solar heat pump system according to the ambient temperature, the water temperature, and the exhaust temperature; the fluorine-containing state includes the refrigerant shortage state.

[0134] A control module 13, which is used to control the working state of the refrigerant compressor according to the fluorine-containing state; the working state includes shutdown and startup.

[0135] Optionally, the control device for the refrigerant shortage state further includes an establishment and storage module 14, which is used to establish the corresponding relationship between the preset temperature range, the preset water temperature, and the alarm exhaust temperature.

[0136] Optionally, the control device for the refrigerant shortage state further includes a refrigerant shortage alarm module 15, which is used to start the refrigerant shortage alarm, and the refrigerant shortage alarm is used for displaying refrigerant shortage alarms.

[0137] It should be noted that the control device for the refrigerant shortage state provided by the embodiment of the present invention can execute the control method for the refrigerant shortage state provided by any embodiment of the present invention, and has the corresponding functional modules and beneficial effects for executing the control method for the refrigerant shortage state, which will not be elaborated here.

[0138] Note that the above is only the preferred embodiment of the present invention and the technical principles applied. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein. The features of each embodiment of the present invention can be partially or fully coupled or combined with each other, and can cooperate with each other in various ways and be technically driven. Various obvious changes, re-adjustments, combinations with each other, and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments. Without departing from the concept of the present invention, it can also include more other equivalent embodiments, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A control method for a fluorine-deficient state, characterized in that, Protection against the state of lack of refrigerant when the refrigerant compressor in the solar heat pump system is working. The preset ambient temperature, preset water temperature and alarm exhaust temperature are pre-stored in the solar heat pump system. The method includes: Obtain the ambient temperature outside, the water temperature in the solar water storage tank and the exhaust temperature of the exhaust hole of the refrigerant compressor; Establish the corresponding relationship between the preset temperature range, preset water temperature and alarm exhaust temperature; Determine the fluorine-containing state of the solar heat pump system according to the ambient temperature, the water temperature and the exhaust temperature, including: Determine the fluorine-containing state of the solar heat pump system according to the comparison result between the ambient temperature and the preset ambient temperature, the comparison result between the water temperature and the preset water temperature, and the comparison result between the exhaust temperature and the alarm exhaust temperature; the fluorine-containing state includes the state of lack of refrigerant; Control the working state of the refrigerant compressor according to the fluorine-containing state; the working state includes shutdown and startup.

2. The control method according to claim 1, characterized in that The preset ambient temperature includes a first preset temperature range, a second preset temperature range, a third preset temperature range and a fourth preset temperature range, and the temperatures of the first preset temperature range, the second preset temperature range, the third preset temperature range and the fourth preset temperature range increase in sequence; the preset water temperature includes a first preset water temperature, a second preset water temperature, a third preset water temperature and a fourth preset water temperature that increase in sequence; Establishing the corresponding relationship between the preset temperature range, preset water temperature and alarm exhaust temperature includes: Obtain the alarm exhaust temperature corresponding to the first preset temperature range and the first preset water temperature according to the pressure-enthalpy diagram of the refrigerant, and establish the corresponding relationship between the first preset temperature range, the first preset water temperature and the alarm exhaust temperature; Obtain the alarm exhaust temperature corresponding to the second preset temperature range and the second preset water temperature according to the pressure-enthalpy diagram of the refrigerant, and establish the corresponding relationship between the second preset temperature range, the second preset water temperature and the alarm exhaust temperature; Obtain the alarm exhaust temperature corresponding to the third preset temperature range and the third preset water temperature according to the pressure-enthalpy diagram of the refrigerant, and establish the corresponding relationship between the third preset temperature range, the third preset water temperature and the alarm exhaust temperature; Obtain the alarm exhaust temperature corresponding to the fourth preset temperature range and the fourth preset water temperature according to the pressure-enthalpy diagram of the refrigerant, and establish the corresponding relationship between the fourth preset temperature range, the fourth preset water temperature and the alarm exhaust temperature.

3. The control method according to claim 2, wherein Determine the fluorine-containing state of the solar heat pump system according to the ambient temperature, the water temperature and the exhaust temperature, including: Judge whether the current ambient temperature is within any one of the first preset temperature range, the second preset temperature range, the third preset temperature range and the fourth preset temperature range; If the current ambient temperature is within any one of the first preset temperature range, the second preset temperature range, the third preset temperature range and the fourth preset temperature range; Based on the corresponding relationship between the preset temperature range, the preset water temperature, and the alarm exhaust temperature, and according to the preset temperature range where the ambient temperature is located and the preset water temperature corresponding to this preset temperature range, determine whether the current water temperature is less than or equal to the preset water temperature; If the water temperature is less than or equal to the preset water temperature, determine whether the exhaust temperature is greater than the alarm exhaust temperature; If the exhaust temperature is greater than the alarm exhaust temperature, determine that the fluorine-containing state of the solar heat pump system is a fluorine-deficient state.

4. The control method according to claim 3, wherein The solar heat pump system includes a fluorine-deficiency alarm; After determining that the fluorine-containing state of the solar heat pump system is a fluorine-deficient state, it further includes: Start the fluorine-deficiency alarm, and the fluorine-deficiency alarm is used for fluorine-deficiency alarm display.

5. The control method according to claim 1, wherein: Control the working state of the refrigerant compressor according to the fluorine-containing state, including: According to the fluorine-containing state of the solar heat pump system being a fluorine-deficient state, control the working state of the refrigerant compressor to alternately stop and start for a preset number of times.

6. The control method according to claim 1, wherein The fluorine-containing state further includes a normal fluorine state; Control the working state of the refrigerant compressor according to the fluorine-containing state, including: According to the normal fluorine state, control the refrigerant compressor to operate normally.

7. A control device for a state of lack of fluorine, which is used to execute the control method for the state of lack of fluorine according to any one of claims 1-6, characterized in that, It includes: A temperature acquisition module for acquiring the ambient temperature outside, the water temperature in the solar water storage tank, and the exhaust temperature of the exhaust hole of the refrigerant compressor; A fluorine-containing state determination module for determining the fluorine-containing state of the solar heat pump system according to the ambient temperature, the water temperature, and the exhaust temperature; the fluorine-containing state includes a fluorine-deficient state; A control module for controlling the working state of the refrigerant compressor according to the fluorine-containing state; the working state includes stop and start.

8. A solar heat pump system, characterized in that, The solar heat pump system includes a microprocessor, and the microprocessor is used to execute the control method for the fluorine-deficient state according to any one of claims 1-6.

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