An electric heating high-efficiency matching heating system and a control method thereof

Abstract

The application provides an electric heat efficient matching heat supply system and a control method thereof, which comprises an electric heat pump and an electric heating two-section combined heat storage and absorption heat pump heat release device, high-temperature heat medium generated by the electric heat pump and the electric heating is used as a driving heat source, and the absorption heat pump is used for supplying heat to users. The electric heat pump is used to heat the heat storage medium to a higher temperature, high-ratio conversion of electric heat is realized, and then the electric heating is used to heat the heat storage medium to a higher temperature, so that the heat storage demand of high temperature is met. The purposes of high temperature and high efficiency are simultaneously realized. The application considers the difference between non-proportional conversion of electricity and heat and different temperatures, and proposes a time-sharing control scheme of the energy storage system. The accurate heat storage amount of the heat storage system can be obtained through calculation. Through the phase change heat storage device, the peak-valley difference is suppressed, and the electricity cost is reduced.

Description

Technical Field

[0001] This invention relates to a system and method thereof, and more particularly to a heating system and control method with high electrothermal matching. Background Technology

[0002] To absorb unstable electrical energy, it is usually stored. Since thermal energy storage is relatively inexpensive, converting electrical energy into heat energy can be used for electric heating. Electric heating converts electricity into heat to achieve heating, and there are two common methods. One is to use electric heating technology, which can heat the thermal storage medium to a high temperature and has advantages such as stable power, wide applicability, and low cost. During the heating process, electricity and heat are converted in a proportional manner. The other is to use heat pump technology, which consumes only a small amount of net reverse circulation work to obtain a large amount of heat supply. Electricity and heat can be converted in a non-proportional manner, making it a highly efficient and energy-saving device that fully utilizes low-grade heat energy.

[0003] However, the proportional thermoelectric conversion characteristic of electric heating technology leads to low conversion efficiency. While heat pump technology can achieve non-proportional thermoelectric conversion, it only converts to lower temperatures, resulting in low-grade heat energy and limited application scenarios. Therefore, existing methods suffer from a contradiction: high heating temperatures and high-efficiency thermoelectric conversion cannot be achieved simultaneously, and this problem remains unresolved, with industry professionals unaware of its existence. The root cause of this contradiction is the inconsistency between the grades of electrical and thermal energy. Existing thermal storage methods cannot fully utilize the advantages of thermal storage systems and cannot achieve efficient high-temperature thermal storage.

[0004] Furthermore, existing technologies for regulating energy storage systems employ linear control methods. This means that the control of the heat storage and release components of the electric heating system is linear regardless of temperature changes (for example, with a constant specific heat capacity, the energy conversion is the same whether the temperature is increased from 70°C to 80°C or from 770°C to 780°C). This involves proportional regulation between heat and electricity, and between heat at different temperatures. However, this is impractical because heat and electricity, and heat at different temperatures, are not equivalent in actual use due to varying heat grades. Therefore, existing heat storage and release control methods cannot achieve accurate control of the energy storage system, thus affecting its efficiency. Summary of the Invention

[0005] The purpose of this invention is to propose a heating control method and device for electrothermal matching from the perspective of energy matching. It also considers the differences in control between electricity and heat, and between heat at different temperatures, and proposes a more practical heat storage and release control method. The technical solution is as follows:

[0006] A heating control method with high-efficiency electrothermal matching, characterized by:

[0007] During off-peak hours, the electric heat pump and electric heater work together to drive the absorption heat pump to provide heat to users. If the combined heating amount is greater than the amount of heat absorbed by the driving heat source required by the absorption heat pump to provide heat to users, the excess heat is stored in a phase change heat storage device.

[0008] During peak electricity periods, the phase change thermal storage device is controlled to be heated by the driving heat source of the absorption heat pump. The insufficient driving heat source is supplied by the combined heating of the electric heat pump and the electric heater.

[0009] During periods of normal electricity supply, the electric heat pump and electric heater are controlled to heat the system, driving the absorption heat pump to provide heat to users and replenishing the heat stored in the phase change thermal storage device.

[0010] Preferably, the compressor compresses the heat absorbed by the electric heat pump from the environment into a high-temperature and high-pressure state and enters the second condenser. The heat transfer fluid absorbs the heat of the working fluid in the second condenser and then enters the electric heater. It flows in from the top side of the four-way valve and flows out from the right side as the driving heat source of the absorption heat pump. The heating cycle is completed by using the absorption heat pump.

[0011] Preferably, the heat generated by the electric heater flows out through the lower side of the four-way valve, and returns to the second condenser after being released by the phase change heat storage device.

[0012] Preferably, the phase change thermal storage device serves as the driving heat source for the absorption heat pump. After passing through the pump, the heat flows in from the left side of the four-way valve and out from the right side, entering the absorption heat pump and completing the heating cycle using the principle of the absorption heat pump.

[0013] This invention also discloses a heating control device with high-efficiency electrothermal matching, characterized by comprising:

[0014] Off-peak electricity period submodule: During off-peak electricity periods, the electric heat pump and electric heater are controlled to work together to drive the absorption heat pump; if the combined heating amount is greater than the amount of heat absorbed by the driving heat source required by the absorption heat pump to provide heat to the user, the excess heat generated is stored in a phase change heat storage device.

[0015] Peak power period sub-module: controls the phase change thermal storage device to be heated by the driving heat source of the absorption heat pump. The insufficient driving heat source is supplied by the combined heating of electric heat pump and electric heater.

[0016] The flat-power sub-module controls the electric heat pump and electric heater to drive the absorption heat pump and replenish the heat stored in the phase change heat storage device.

[0017] o

[0018] This invention also discloses a heating system with high-efficiency matching of electric and thermal power. Based on the aforementioned high-efficiency matching heating control device, the system further includes a two-stage combined heating system of electric heat pump and electric heating, a phase change thermal storage device for heat storage, and an absorption heat pump for heat release. Its features include: the phase change thermal storage device stores the heat from the two-stage combined heating during off-peak and flat electricity periods, and releases the heat during peak electricity periods to drive the absorption heat pump for heating; during the heat storage stage, the high-temperature heat medium generated by the electric heat pump and electric heating serves as the driving heat source; during the heat release stage, the absorption heat pump releases heat to provide heating to users; the electric heat pump heats the working fluid to a higher temperature, achieving a high-rate conversion of electric and thermal power, and then uses electric heating to heat the heat storage medium to an even higher temperature, meeting the high-temperature heat storage requirements; then, the high-grade heat drives the absorption chiller to generate a large amount of low-grade heat, achieving a non-proportional conversion between heat at different temperatures.

[0019] The present invention also discloses a non-volatile storage medium, characterized in that the non-volatile storage medium includes a stored program, wherein the program, when running, controls the device where the non-volatile storage medium is located to execute the method described above.

[0020] The present invention also discloses an electronic device, characterized in that it comprises a processor and a memory; the memory stores computer-readable instructions, and the processor is used to execute the computer-readable instructions, wherein the computer-readable instructions execute the method described above.

[0021] Beneficial effects:

[0022] (1) This invention proposes a heating control method that matches electricity and heat during different periods of off-peak, peak, and flat electricity to achieve a high-rate conversion of electricity and heat; at the same time, it uses electric heating to heat the heat storage medium to a higher temperature, meeting the high-temperature heat storage requirements. It simultaneously achieves the goals of high temperature and high efficiency.

[0023] (2) This invention takes into account the difference in non-proportional conversion between electricity and heat, and heat at different temperatures, and proposes time-sharing (valley electricity, peak electricity, flat electricity) control of the energy storage system, so as to obtain the precise heat storage capacity of the thermal storage system. At the same time, through the phase change thermal storage device, the peak-valley difference is smoothed out and the electricity cost is reduced. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the combined heat pump and electric heating system of the present invention.

[0025] The components are: 1. Compressor, 2. Second evaporator, 3. Second condenser, 4. Expansion valve, 5. Absorption heat pump, 6. First condenser, 7. Throttling valve, 8. First evaporator, 9. Absorber, 10. Solution pump, 11. Solution heat exchanger, 12. Solution valve, 13. Electric heater, 14. Four-way valve, 15. First valve, 16. Pump, 17. Phase change heat storage device, 18. Second valve. Detailed Implementation

[0026] Example 1

[0027] A high-efficiency electric heating system includes a two-stage combined heating system of electric heat pump and electric heater, a phase change heat storage device, and an absorption heat pump heat release device. The system uses the high-temperature heat medium generated by the electric heat pump and electric heater as the driving heat source, and the absorption heat pump provides heating to users. The phase change heat storage device stores or releases heat according to different operating stages: In the heat storage stage, a heat storage module is composed of a compressor 1, a second evaporator 2, a second condenser 3, an expansion valve 4, an electric heater 13, a four-way reversing valve 14, a phase change heat storage device 17, and a second valve 18. First, the electric heat pump absorbs heat from the environment, and the compressor compresses the working fluid to a high-temperature, high-pressure state. Then, heat is exchanged with the heat medium in the condenser. After absorbing heat, the heat medium reaches a higher temperature and enters the electric heater to further increase its temperature, ultimately serving as the driving heat source for the absorption heat pump, generating a large amount of low-temperature heat energy. The excess heat is stored in the phase change heat storage device. The heat absorbed by the electric heat pump from the environment enters the second evaporator 2, then is compressed into a high-temperature, high-pressure state by the compressor 1 before entering the second condenser 3. The heat transfer fluid absorbs the heat from the working fluid in the second condenser 3 and then enters the electric heater 13, flowing in from the upper side of the four-way valve 14 and out from the right side, serving as the driving heat source for the absorption heat pump 5. The heating cycle is completed using the principle of the absorption heat pump. During off-peak and normal electricity periods, the excess heat generated by the electric heater 13 flows out through the lower side of the four-way valve 14, is released by the phase change heat storage device 17, and then returns to the second condenser 3 through the second valve 18.

[0028] During the heat release phase, the heat stored in the thermal storage module is released to the driving heat source of the absorption heat pump. The working components after being released to the absorption heat pump include the absorption heat pump generator 5, the first condenser 6, the throttling valve 7, the first evaporator 8, the absorber 9, the solution pump 10, the solution heat exchanger 11, the solution valve 12, and the first valve 15. During off-peak and off-peak electricity periods, the heat from the thermal storage module flows in from the upper side of the four-way valve 14 and out from the right side, used to heat the driving heat source of the absorption heat pump generator 5, completing the heating cycle using the principle of the absorption heat pump. A large amount of low-grade heat Q is generated after passing through the absorber 9 and the first condenser 6. sup This increases the temperature of the heating water. The cooled driving heat source returns directly to the second condenser 3 for reheating. The low-temperature waste heat after heating the driving heat source can enter the first evaporator 8 to release heat to the low-pressure working fluid in the evaporator. The waste water is further cooled and then returns to the second condenser 3 to complete the entire cycle. During peak power periods, the driving heat source is heated by the phase change heat storage device 17. After passing through the pump 16, it flows in from the left side of the four-way valve 14 and out from the right side, entering the absorption heat pump generator 5. The heating cycle is completed using the principle of absorption heat pump, and low-grade heat energy Q is generated after passing through the absorber 9 and the first condenser 6. supThis increases the temperature of the heating water. The cooled driving heat source flows back to the phase change heat storage device 17 through the first valve 15. If the heat is insufficient to meet the user's heat demand, an electric heat pump and electric heater 13 will provide auxiliary heating.

[0029] This invention proposes a two-stage combined heating system using an electric heat pump and an electric heater, a phase change thermal storage device, and an absorption heat pump for heating. The electric heat pump heats the working fluid to a high temperature, achieving a high-rate electrothermal conversion. The working fluid then enters the electric heater, where electric heating further heats the storage medium to an even higher temperature, meeting the high-temperature thermal storage requirements. The electric heater, phase change thermal storage device, and absorption heat pump are connected via a four-way valve to allow for switching between different operating modes at different times. The high-grade heat generated by the electric heater directly drives the absorption chiller, or it can be stored in the phase change thermal storage device first, and then the phase change thermal storage device drives the absorption chiller to generate a large amount of low-grade heat, achieving a non-proportional conversion of heat between different temperatures.

[0030] For an electric heat pump, one unit of electricity can produce multiple units of heat energy. Let the power of the compressor be W0, and the coefficient of performance (COP) of the heat pump be COP. HP Then the heat dissipation power Q of the condenser c2 for:

[0031] Q c2 =W0·COP HP (1)

[0032] For an electric heater, one unit of electricity can only produce one unit of heat. Its heating power Q eb That is, electrical power W eb :

[0033] Q eb =W eb (2)

[0034] For an absorption heat pump, a small amount of high-grade heat energy from a driving heat source is converted into a large amount of low-grade heat energy for the user. Let the high-grade heat energy consumed by the generator have a heating power of Q. g The coefficient of performance (COP) of an absorption heat pump is... AHP The heat release power Q of low grade sup for:

[0035] Q sup =Q g CoP AHP (3).

[0036] Example 2

[0037] This invention also discloses a control method for a heating system with high-efficiency electrothermal matching, including the aforementioned high-efficiency electrothermal matching heating system.

[0038] This invention proposes a time-sharing control scheme for energy storage systems, while also addressing the issue of the coefficient of performance (COP) of absorption heat pumps. AHP It is necessary to monitor the user's heat load demand and the heat storage and release status of the phase change thermal storage device, and to determine the user's heat supply demand Q. sup / COP AHP and Q PH The heat storage and release power of the phase change thermal energy storage device is controlled by comparison. The specific control flow of the system is as follows:

[0039] 1. During off-peak hours, the electric heat pump and electric heater work together to drive the absorption heat pump to provide heat to users. If the amount of heat generated is greater than the amount of heat absorbed by the driving heat source required by the absorption heat pump to provide heat to users, the excess heat is stored in the phase change heat storage device 17.

[0040] First, an electric heat pump absorbs heat from the environment. Compressor 1 consumes a small amount of electricity to compress the working fluid into a high-temperature, high-pressure state before it enters the second condenser 3. The heat transfer fluid absorbs heat from the working fluid in the condenser, raising its temperature to t. 17 It then enters the electric heater 13, where the temperature rises to t. 15 (Around 120℃) The solution flows in from the top of the four-way valve 14 and out from the right, serving as the driving heat source for the absorption heat pump generator 5. After the dilute solution in the generator is heated, the working fluid evaporates and enters the first condenser 6, where it releases heat and condenses into a saturated liquid. After passing through the throttling valve 7, the temperature and pressure decrease, and it enters the first evaporator 8, where it absorbs heat from the external heat source and becomes low-pressure steam. It then enters the absorber 9 and is absorbed by the concentrated solution from the generator 5, becoming a dilute solution. After passing through the solution pump 10 and the solution heat exchanger 11 to complete the solution cycle, it returns to the generator 5 to complete the solution cycle. The heating water directly passes through the absorber 9 and the first condenser 6 of the absorption heat pump to obtain a large amount of low-grade heat Q. sup This increases the temperature of the heating water. The cooled driving heat source returns to the second condenser 3 to be reheated. Simultaneously, the low-temperature waste heat from heating the driving heat source flows out from the generator 5 and enters the first evaporator 8 to release heat to the low-pressure working fluid in the evaporator. The waste water is further cooled and then returns to the second condenser 3 to complete the entire cycle. Excess heat generated by the electric heater 13 flows in from the upper side and out from the lower side through the four-way valve 14. After being released by the phase change heat storage device 17, it returns to the second condenser 3 through the second valve 18.

[0041] The total electrical power W of the combined heating of the electric heat pump and the electric heater is [not specified]. tot Total heating power Q sto They are respectively:

[0042] W tot =W0+W eb (4)

[0043]

[0044] The heating power required to drive the absorption heat pump is Q. sup / COP AHP The maximum heat storage capacity of the phase change thermal energy storage device is:

[0045] Q PH =Q sto -Q sup / COP AHP (6)

[0046] Within time period i, if the total heat supply when using the maximum heat storage power is greater than the total heat required for the phase change thermal storage device to reach full capacity, then the heat storage power for that time period is: charge = (1 - SOC) i If the total heat supply when using the maximum heat storage power is insufficient to bring the phase change heat storage device to full capacity, then the maximum heat storage power shall be used for heat storage.

[0047] 2. During peak electricity periods, the phase change thermal storage device first serves as the driving heat source for the absorption heat pump, and any remaining heat is supplied by a combination of an electric heat pump and an electric heater.

[0048] The phase change heat storage device 17 heats the driving heat source. After passing through pump 16, the heat flows in from the left side of the four-way valve 14 and out from the right side, entering the absorption heat pump generator 5. The dilute solution in the generator is heated, and the working fluid evaporates and enters the first condenser 6, where it releases heat and condenses into a saturated liquid. After passing through the throttling valve 7, its temperature and pressure decrease, and it enters the first evaporator 8, where it absorbs heat from the external heat source, becoming low-pressure steam. This steam then enters the absorber 9, where it is absorbed by the concentrated solution from generator 5, becoming a dilute solution. After passing through the solution pump 10 and solution heat exchanger 11 to complete the solution cycle, it returns to generator 5 to complete the cycle. The heating water directly passes through the absorber 9 and the first condenser 6 of the absorption heat pump to obtain a large amount of low-grade heat Q. sup This increases the temperature of the heating water. The cooled driving heat source flows back to the phase change heat storage device 17 through the first valve 15. If the heat is insufficient to meet the user's heat demand, auxiliary heating is provided by the electric heat pump and electric heater 13.

[0049] The maximum power output of the phase change thermal storage device is: Q PH =Q sto -Q sup / COP AHP .

[0050] Within time period i, if the thermal storage power in the phase change thermal storage device is greater than the absorption power (SOC) of the driving heat source required by the absorption heat pump to supply heat to the user... i ·full / i>Q sup / COP AHPThis indicates that the heat storage capacity of the thermal storage device during this period is sufficient to meet the heat absorption capacity of the driving heat source required by the absorption heat pump to provide heating to the user. Simultaneously, if the maximum heat release power of the phase change thermal storage device is greater than the heat absorption power (Q) of the driving heat source required by the absorption heat pump to provide heating to the user... PH >Q sup / COP AHP If the phase change thermal storage device can meet the heating requirements during this period, then the heat release power of the phase change thermal storage device is: charge = Q sup / COP AHP If the maximum heat storage and release power of the phase change thermal storage device is less than the heat absorption power (Q) required by the absorption heat pump to supply heat to the user, then... PH <Q sup / COP AHP This indicates that during this period, the heat released by the phase change thermal storage device at maximum power is insufficient to meet the heat absorption requirements of the absorption heat pump for powering the user. Therefore, the heat release power of the phase change thermal storage device during this period is its maximum heat release power: charge = Q. PH .

[0051] If the heat storage capacity in the phase change thermal storage device is less than the heat absorption capacity (SOC) of the driving heat source required by the absorption heat pump to supply heat to the user, i ·full / i<Q sup / COP AHP This indicates that the heat storage capacity of the thermal storage device during this period cannot meet the heat absorption capacity of the absorption heat pump required to provide heating to users. Simultaneously, if the maximum heat release power of the phase change thermal storage device exceeds its heat storage capacity (Q), it indicates that the heat storage capacity of the phase change thermal storage device is insufficient. PH >SOC i If (full / i), then the heat stored in the phase change thermal storage device can be completely released for heating during this period. The heat release power of the phase change thermal storage device is: charge = SOC i ·full / i; If the maximum heat storage and release power of the phase change thermal energy storage device is less than its heat storage power (Q) PH <SOC i The value of ·full / i) indicates that even at maximum power, the phase change thermal storage device cannot fully release the stored heat during this period. The heat release power of the phase change thermal storage device is the maximum heat release power: charge = Q PH .

[0052] 3. During periods of normal power supply, the thermal storage device will not participate in heating. Instead, it will be heated by an electric heat pump and electric heater 13 to drive the absorption heat pump and provide heating for users. At the same time, the amount of heat stored in the thermal storage device will be replenished.

[0053] During time period i, if the thermal storage capacity SOC of the phase change thermal storage device is... iIf the thermal energy storage capacity is ≤0.4, then the heat release power of the phase change thermal storage device during this period is: charge = 0.1·full / i; if the thermal energy storage capacity of the phase change thermal storage device is 0.4 < SOC i If the value is ≤0.5, then the heat release power of the phase change thermal storage device during this period is: charge=(0.5-SOC) i )·full / i.

[0054] 4. For absorption heat pumps, the heat exchange capacity of each component can be calculated. The known conditions are as follows: Heating outlet water temperature t 12 Heating return water temperature t 10 evaporator waste hot water inlet temperature t 13 Return water temperature t 14 .

[0055] (1) For the generator, its heat consumption Q g The driving steam mass flow rate q3 is determined according to equation (7):

[0056] Q g =q3c p (t 15 -t 16 (7)

[0057] In the formula, t 15 t is the generator inlet temperature. 16 This refers to the generator outlet temperature.

[0058] (2) For the absorber, the heat released is Q a The mass flow rate of the heated hot water is determined according to equation (8):

[0059] Q a =q1c p (t 11 -t 10 (8)

[0060] In the formula, t 11 t is the absorber outlet temperature. 10 This refers to the absorber inlet temperature.

[0061] (3) For the condenser, its heat release is determined according to equation (9):

[0062] Q c =q1c p (t 12 -t 11 (9)

[0063] In the formula, t 12 t is the temperature at the condenser outlet. 11 This refers to the absorber outlet temperature.

[0064] (4) For the evaporator, its heat absorption and the mass flow rate of the waste hot water are determined according to equation (10):

[0065] Q e =q2c p (t 13 -t 14 (10)

[0066] In the formula, t 13 t represents the temperature of the waste hot water at the evaporator inlet. 14 The temperature of the residual hot water at the evaporator outlet.

[0067] (5) The heat input and output of the absorption heat pump are conserved. When the pump work is neglected, equation (11) holds true:

[0068] Q sup =Q e +Q g =Q a +Q c (11)

[0069] For absorption heat pumps, select an appropriate heat transfer temperature difference and determine the evaporation temperature, condensation temperature, generator concentrated solution outlet temperature t8, and absorber inlet and outlet temperatures t9 and t5. Based on the generator pressure, absorber pressure, evaporator pressure, and condenser pressure, refer to the hx diagram to determine the enthalpy h and mass fraction x for points 1-9. o Let D be the circulating flow rate of the working fluid at points t1, t2, and t3. Determine the circulating flow rate G of the dilute solution according to equation (12). o Finally, the calculation of the absorption heat pump is completed according to equations (7)-(12).

[0070] Gx6=(GD)x8 (12)

[0071] This invention proposes a two-stage combined thermal storage scheme using an electric heat pump and electric heating. This scheme leverages the high-efficiency electrothermal conversion of the electric heat pump while utilizing electric heating to meet high-temperature thermal storage requirements, resulting in a clean, efficient, energy-saving, and environmentally friendly solution. Through a phase-change thermal storage device, a time-segmented thermal storage and release control strategy is proposed, which can smooth out peak-valley differences and reduce electricity costs. Simultaneously, during control, the differences in the non-proportional conversion between electricity and heat, and between heat at different temperatures, are considered, based on the electro-thermal conversion coefficient (COP). HP The non-uniform conversion factor (COP) between heat at different temperatures AHP The precise heat storage capacity Q of the system is obtained through calculation. PH =Q sto -Q sup / COP AHP =W0·COP HP +W eb -Q sup / COPAHP Heat release Q sup =Q g COP AHP This allows for precise control of the system. If the differences between electricity and heat, and between heat at different temperatures, are not considered and controlled merely as linear changes, inaccurate control of the system will result in significant energy loss Q. loss =W0·(COP) HP -1)+Q g ·(COP AHP -1), losses exceeded 40%.

[0072] Compared to traditional direct heating systems using electric heating and heat storage devices, this invention can significantly improve system efficiency. For example, when both systems consume the same amount of electricity (W)... eb =W tot When the power density is 1 kWh, the proposed system efficiency is 200% higher than that of the traditional system, as shown in the following calculation:

[0073] (1) A traditional electric heating + heat storage device direct heating system can provide heat to users, with a heat output Q eb =W eb =1kWh, of which heat dissipation accounts for about 10%, then the total heat generated is Q. sto =Q eb ·(1-10%)=1kWh·(1-10%)=0.9kWh, then the system efficiency is:

[0074]

[0075] (2) In the system proposed in this invention, assuming the COP of the electric heat pump is 3 and the COP of the absorption heat pump is 1.5, the heat generated by the combined heating of the electric heat pump and the electric heater can be completely used to heat the driving heat source of the absorption heat pump. The power consumption W for the combined heating of the electric heat pump and the electric heater is... tot For a capacity of 1 kWh, the power consumption of the electric heat pump and electric heating is W0 = W. eb =0.5kWh, and the heat dissipation of each accounts for 10% of the heat production, then the total heat produced is Q. sto =Q c2 ·(1-10%)+Q eb • (1-10%) = 0.5 kWh • 3 • (1-10%) + 0.5 kWh • (1-10%) = 1.8 kWh, the heat used to drive the absorption heat pump generator is Q. g =Q sto =1.8kWh, then the heat supply Q sup =2.7kWh, then the system efficiency is:

[0076] (3) Improved system efficiency:

[0077] Example 3

[0078] A heating device with high-efficiency electrothermal matching, comprising:

[0079] Off-peak electricity period submodule: During off-peak electricity periods, the electric heat pump and electric heater work together to drive the absorption heat pump 5 to provide heat to users; if the combined heating amount is greater than the amount of heat absorbed by the driving heat source required by the absorption heat pump 5 to provide heat to users, the excess heat generated is stored in the phase change heat storage device 17.

[0080] Peak power period sub-module: The phase change heat storage device 17 is used to heat the driving heat source of the absorption heat pump 5. The insufficient driving heat source is supplied by the combined heating of the electric heat pump and the electric heater.

[0081] During the power outage period, the sub-module uses an electric heat pump and an electric heater 13 to heat and drive the absorption heat pump 5 to provide heat to users, while simultaneously replenishing the heat stored in the phase change heat storage device 17.

[0082] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. An electric heat high-efficiency matched heat supply system, comprising an electric heat pump and an electric heating two-stage combined heating, a phase change heat storage device, an absorption heat pump heat release device, the phase change heat storage device stores the heat of the two-stage combined heating during valley electricity and flat electricity period, and releases heat to drive the absorption heat pump to supply heat during peak electricity period. In the heat storage stage, an electric heat pump and a high-temperature heat medium generated by electric heating serve as the driving heat source. In the heat release stage, an absorption heat pump is used to release heat to supply users. The electric heat pump heats the working fluid to a higher temperature, achieving a high-rate electrothermal conversion. Then, electric heating is used to heat the heat storage medium to an even higher temperature, meeting the high-temperature heat storage requirements. The high-grade heat then drives an absorption chiller to generate a large amount of low-grade heat, achieving a non-proportional conversion between heat at different temperatures. Its characteristics are: In the heat storage stage, the heat storage module consists of a compressor, a second evaporator, a second condenser, an expansion valve, an electric heater, a four-way reversing valve, a phase change heat storage device, and a second valve. First, an electric heat pump absorbs heat from the environment, and the compressor compresses the working fluid to a high-temperature, high-pressure state. Then, it exchanges heat with the heat medium in the condenser. After absorbing heat, the heat medium reaches a higher temperature and enters the electric heater to further increase its temperature, ultimately serving as the driving heat source for the absorption heat pump, generating a large amount of low-temperature heat energy. Excess heat is stored using the phase change heat storage device. The heat absorbed by the electric heat pump from the environment enters the second evaporator, is compressed to a high-temperature, high-pressure state by the compressor, and then enters the second condenser. The heat transfer fluid absorbs heat from the working fluid in the second condenser and enters the electric heater, flowing in from the top of the four-way valve and out from the right side, serving as the driving heat source for the absorption heat pump. The heating cycle is completed using the principle of the absorption heat pump. During off-peak and off-peak electricity periods, excess heat generated by the electric heater flows out through the bottom of the four-way valve, is released by the phase change heat storage device, and then returns to the second condenser through the second valve. During the heat release phase, the heat stored in the thermal storage module is released to the driving heat source of the absorption heat pump. The working components after being released to the absorption heat pump include the absorption heat pump generator, the first condenser, the expansion valve, the first evaporator, the absorber, the solution pump, the solution heat exchanger, the solution valve, and the first valve. During off-peak and normal electricity periods, the heat from the thermal storage module flows in from the top of the four-way valve and out from the right, used to heat the driving heat source of the absorption heat pump generator, completing the heating cycle using the principle of the absorption heat pump. A large amount of low-grade heat Q is generated after passing through the absorber and the first condenser. sup The process involves several steps: first, increasing the temperature of the heating water; second, cooling the driving heat source, which then returns directly to the second condenser for reheating; and third, releasing the low-temperature waste heat from heating the driving heat source into the first evaporator to cool the low-pressure working fluid. The waste water then returns to the second condenser after further cooling to complete the cycle. During peak electricity periods, the driving heat source is heated using a phase change heat storage device. After passing through a pump, the heat flows in from the left side of the four-way valve and out from the right side, entering the absorption heat pump generator. The heating cycle is completed using the principle of the absorption heat pump, generating low-grade heat energy Q through the absorber and the first condenser. sup The cooling process increases the temperature of the heating water; the cooled driving heat source flows back to the phase change heat storage device through the first valve; if the heat is insufficient to meet the user's heat demand, auxiliary heating is provided by an electric heat pump and an electric heater; for the electric heat pump, one unit of electricity produces multiple units of heat energy; let the electric power of the compressor be W0, and the coefficient of performance of the electric heat pump be COP. HP Then the heat dissipation power Q of the condenser c2 for: Q c2 = W0· COP HP (1) For the electric heater, 1 part of electricity can only produce 1 part of heat; its heating power Q eb That is, the electric power W eb : Q eb = W eb (2) For the absorption heat pump, it converts the high-grade heat energy of a small amount of driving heat source into a large amount of low-grade heat energy for supplying users; the high-grade heat energy consumed by the generator is set as its heating power Q g , the heating coefficient of the absorption heat pump is COP AHP , and then the low-grade heat release power Q sup is: Q sup = Q g • CoP AHP (3).

2. A control method for a heating system with high-efficiency electrothermal matching, comprising the heating system with high-efficiency electrothermal matching as described in claim 1, characterized in that: The time-sharing control scheme of the energy storage system, and due to the existence of the absorption heat pump heating coefficient COP AHP , needs to monitor the user's heat load demand power and the heat storage and release state of the phase change heat storage device, according to the user's heat supply demand Q sup / COP AHP and Q PH contrast, and then control the heat storage and release power of the phase change heat storage device; the specific control process of the system is: During off-peak hours, the electric heat pump and electric heater work together to drive the absorption heat pump to provide heat to users. If the heating amount is greater than the amount of heat absorbed by the driving heat source required by the absorption heat pump to provide heat to users, the excess heat is stored in a phase change heat storage device. First, an electric heat pump absorbs heat from the environment. A compressor consumes a small amount of electricity to compress the working fluid into a high-temperature, high-pressure state before it enters the second condenser. The heat transfer fluid absorbs heat from the working fluid in the condenser, raising its temperature to t. 17 It then enters the electric heater, where the temperature rises to t. 15 The solution flows in from the top of the four-way valve and flows out from the right side, serving as the driving heat source for the absorption heat pump generator. After the dilute solution in the generator is heated, the working fluid evaporates and enters the first condenser, where it releases heat and condenses into a saturated liquid. After passing through the throttling valve, the temperature and pressure decrease, and after entering the first evaporator, it absorbs heat from the external heat source and becomes low-pressure steam. It then enters the absorber and is absorbed by the concentrated solution from the generator to become a dilute solution. After completing the solution cycle through the solution pump and solution heat exchanger, it returns to the generator to complete the solution cycle. The heating water directly passes through the absorber and the first condenser of the absorption heat pump to obtain a large amount of low-grade heat Q sup , and the temperature of the heating water is increased; the cooled driving heat source returns to the second condenser to be heated again; the low-temperature waste heat after heating the driving heat source flows out from the generator and enters the first evaporator to release heat to the low-pressure working medium in the evaporator, and the waste heat water is further cooled and returns to the second condenser to complete the entire cycle; the excess heat generated by the electric heater flows in through the upper side of the four-way valve and flows out through the lower side, releases heat after passing through the phase change heat storage device, and returns to the second condenser through the second valve; wherein the total electric power W tot and the total heating power Q sto of the electric heat pump and the electric heater combined heating are respectively: W tot = W0+ W eb (4) wherein Q is the heating power required to drive the absorption heat pump sup / COP AHP The maximum heat storage power of the phase change heat storage device is: Q PH = Q sto - Q sup / COP AHP (6) During peak electricity periods, the phase change thermal storage device first serves as the driving heat source for the absorption heat pump, and any insufficient heat is then supplied by a combination of electric heat pump and electric heater. A phase change thermal energy storage device is used to heat the driving heat source. After being pumped, the heat flows in from the left side of a four-way valve and out from the right side, entering the absorption heat pump generator. The dilute solution in the generator is heated, and the working fluid evaporates and enters the first condenser, where it releases heat and condenses into a saturated liquid. After passing through a throttling valve, its temperature and pressure decrease, and it enters the first evaporator, where it absorbs heat from the external heat source, becoming low-pressure vapor. This vapor then enters the absorber where it is absorbed by the concentrated solution from the generator, becoming a dilute solution. After passing through a solution pump and a solution heat exchanger to complete the solution cycle, it returns to the generator to complete the solution cycle. If the heat is insufficient to meet the demand... The heating demand of users is supplemented by electric heat pumps and electric heaters. During time period i, if the heat storage power of the phase change thermal storage device is greater than the heat absorption power of the driving heat source required by the absorption heat pump to heat the users, it indicates that the heat storage capacity of the thermal storage device can meet the heat absorption capacity of the driving heat source required by the absorption heat pump to heat the users during that time period. Simultaneously, if the maximum heat release power of the phase change thermal storage device is greater than the heat absorption power of the driving heat source required by the absorption heat pump to heat the users, then the phase change thermal storage device can meet the heating requirements during that time period. The heat release power of the phase change thermal storage device is: charge = Q sup / COP AHP If the maximum heat storage and release power of the phase change thermal storage device is less than the heat absorption power Q of the driving heat source required by the absorption heat pump to supply heat to the user... PH <Q sup / COP AH This indicates that during this period, the heat released by the phase change thermal storage device at maximum power is insufficient to meet the heat absorption requirements of the absorption heat pump for powering users. Therefore, the heat release power of the phase change thermal storage device during this period is its maximum heat release power: charge = Q. PH ; If the heat storage capacity of the phase change thermal storage device is less than the heat absorption capacity of the driving heat source required by the absorption heat pump to provide heating to the user, it indicates that the heat storage capacity of the thermal storage device cannot meet the heat absorption capacity of the driving heat source required by the absorption heat pump to provide heating to the user during this period. Simultaneously, if the maximum heat release capacity of the phase change thermal storage device is greater than its heat storage capacity, then the heat stored in the phase change thermal storage device will be completely released for heating during this period. If the maximum heat storage and release capacity of the phase change thermal storage device is less than its heat storage capacity, it indicates that even if the phase change thermal storage device uses its maximum power for heating during this period, it cannot completely release the stored heat, and the heat release capacity of the phase change thermal storage device is its maximum heat release capacity. charge = Q PH ; During periods of normal power supply, the thermal storage device will not participate in heating. Instead, it will be heated by electric heat pumps and electric heaters to drive the absorption heat pump and provide heat to users. At the same time, the amount of heat stored in the thermal storage device will be replenished. For the absorption heat pump, the heat exchange of each device of the absorption heat pump is obtained by calculation; the known conditions are as follows: the supply water temperature t 12 for heating, the return water temperature t 10 for heating, the waste heat water inlet temperature t 13 of the evaporator, and the return water temperature t 14 ; (1) for the generator, the heat consumption Q g and the drive steam mass flow rate q3 is determined according to equation (7): Q g = q3c p (t 15 -t 16 ) (7) where t 15 is the generator inlet temperature, t 16 is the generator outlet temperature; (2) for the absorber, the amount of heat Q a and the mass flow rate q1 of the heated hot water is determined according to equation (8): Q a = q1c p (t 11 -t 10 ) (8) where t 11 is the absorber outlet temperature; t 10 is the absorber inlet temperature; (3) For the condenser, the amount of heat Q c and the mass flow rate q1 of the heated hot water is determined according to equation (9): Q c = q1c p (t 12 -t 11 ) (9) where t 12 is the temperature at the outlet of the condenser, t 11 is the temperature at the outlet of the absorber; (4) For the evaporator, the heat absorption amount Q e and the mass flow rate q2 of the waste heat water are determined according to equation (10): Q e = q2c p (t 13 -t 14 )(10) where t 13 is the temperature of the exhaust water at the inlet of the evaporator; t 14 is the temperature of the exhaust water at the outlet of the evaporator; (5) The heat input and output of the absorption heat pump are conserved; when the pump work is ignored, equation (11) holds true: Q sup = Q e + Q g = Q a + Q c (11).

3. An electrically heated, high-efficiency matched heat supply device, which uses the method according to claim 2, characterized in that: Valley power period submodule: when in valley power period, run the electric heat pump and electric heater combined heating drive absorption heat pump work, for user heating; if the combined heating quantity is greater than the driving heat source heat absorption quantity required by absorption heat pump for user heating, the excess heat is stored by phase change heat storage device; Peak power period submodule: heat the driving heat source of absorption heat pump through phase change heat storage device, and the insufficient driving heat source is supplied by electric heat pump and electric heater combined heating; Flat power period submodule: use electric heat pump and electric heater to heat the driving absorption heat pump work for user heating, and supplement the heat storage quantity of phase change heat storage device.

Images