Air energy heat pump water heater and heat pump system and control system thereof

Abstract

The utility model provides an air energy heat pump water heater and a heat pump system and a control system thereof. The control system comprises a bridgeless PFC rectification module and a control module, one end of the bridgeless PFC rectification module is configured to be connected with the heat pump module, and the other end of the bridgeless PFC rectification module is configured to be connected with the alternating current access end and used for conducting alternating current and direct current conversion; the control module is connected with the heat pump module and the bridgeless PFC rectification module and is configured to control starting and stopping of an execution structure of the heat pump module and on-off of the bridgeless PFC rectification module. According to the utility model, the bridgeless PFC rectifier module is adopted to carry out AC-DC conversion and provide DC voltage for the heat pump module, so that the on-state loss can be reduced, the control module controls the start and stop of an execution structure of the heat pump module and the on-off of the bridgeless PFC rectifier module, the integration of parts is realized, the number and volume of circuit components are reduced, the power consumption is reduced, and the energy efficiency of the system is improved; and the purposes of energy conservation and emission reduction are achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of air energy heat pump water heaters, in particular to an air energy heat pump water heater and a heat pump system and a control system thereof. Background Art

[0002] A heat pump is defined as a refrigerator that can realize the conversion of evaporator and condenser functions. We can also call a heat pump a unit that works based on the reverse Carnot cycle principle and can be used for both cooling and heating.

[0003] The air-source heat pump hot and cold water units are placed on the roof of the building. There is no need to set up a special refrigeration room or boiler room, and the building space occupied by chimneys and cooling water pipes is also saved. The system equipment involved is small and the operation is centralized, and the maintenance and management are simple and convenient, which is increasingly favored by users.

[0004] At present, the circuit for converting AC / DC for the heat pump module in the air-energy heat pump water heater uses a bridge PFC circuit. In the positive and negative half cycles of the AC input, two diodes in the rectifier bridge participate in the circuit, which has both the voltage drop loss of the diode and the reverse recovery loss, which is not conducive to improving the energy efficiency of the system. In addition, the air-energy heat pump control system has many components and redundant structure, which will also increase the power consumption of the circuit.

[0005] In view of this, the present utility model is proposed. Utility Model Content

[0006] The technical problem to be solved by the present invention is to at least overcome some of the shortcomings of the prior art and provide a control system for an air-to-air heat pump system. By adopting a bridgeless PFC rectifier module for AC-DC conversion, a DC voltage is provided for the heat pump module, which can reduce the conduction loss. The control module controls the start and stop of the execution structure of the heat pump module and the switch of the bridgeless PFC rectifier module, thereby realizing component integration, reducing the number and volume of circuit components, reducing power consumption, improving system energy efficiency, and achieving the purpose of energy conservation and emission reduction.

[0007] In order to solve the above technical problems, the first aspect of the utility model is to provide a control system for an air energy heat pump system, comprising:

[0008] A bridgeless PFC rectifier module, one end of which is configured to be connected to the heat pump module, and the other end of which is configured to be connected to the AC access terminal for performing AC-DC conversion;

[0009] The control module is connected to the heat pump module and the bridgeless PFC rectifier module respectively, and is configured to control the start and stop of the execution structure of the heat pump module and the switch of the bridgeless PFC rectifier module.

[0010] In some embodiments, the bridgeless PFC rectifier module includes:

[0011] A pre-processing circuit for stabilizing the input AC voltage;

[0012] The bridgeless PFC circuit is used to convert the stabilized AC voltage into a DC voltage.

[0013] In some implementations, the pre-processing circuit includes a common mode filter.

[0014] In some embodiments, the common mode filter includes a common mode inductor, a first capacitor and a second capacitor;

[0015] Among them, the input end of the common-mode inductor is connected to the AC access end, one end of the first capacitor is connected to an output end of the common-mode inductor, the other end of the first capacitor is grounded, one end of the second capacitor is connected to the other output end of the common-mode inductor, and the other end of the second capacitor is grounded.

[0016] In some implementations, a filter capacitor and a discharge resistor are arranged in parallel between the output end of the common-mode inductor and one end of the first capacitor and the second capacitor.

[0017] In some implementations, a third capacitor for suppressing differential mode noise is further provided between the input end of the common mode inductor and the AC access end.

[0018] In some embodiments, the bridgeless PFC circuit includes a reactor, a first high-frequency power tube, a second high-frequency power tube, a first low-frequency diode, a second low-frequency diode, and an output capacitor;

[0019] Wherein, one end of the reactor is connected to the preprocessing circuit, and the other end is connected to the first high-frequency power tube and the second high-frequency power tube;

[0020] The control ends of the first high-frequency power tube and the second high-frequency power tube are connected to the control module;

[0021] Two ends of the output capacitor are respectively connected to a connection node between the first high-frequency power tube and the first low-frequency diode, and a connection node between the second high-frequency power tube and the second low-frequency diode.

[0022] In some embodiments, the output capacitor includes an absorption capacitor and a film capacitor connected in parallel.

[0023] In some implementations, the first high-frequency power tube and the second high-frequency power tube are silicon carbide MOS tubes.

[0024] The second aspect of the utility model further provides an air energy heat pump system, comprising a heat pump module and the control system for the air energy heat pump system according to the above, wherein the heat pump module is connected to the control module and the bridgeless PFC rectifier module.

[0025] The third aspect of the utility model also provides an air energy heat pump water heater, comprising the air energy heat pump system according to the above.

[0026] After adopting the above technical scheme, the utility model has the following beneficial effects compared with the prior art.

[0027] (1) The air energy heat pump system provided by the utility model adopts a bridgeless PFC rectifier module to perform AC-DC conversion, provides a DC voltage for the heat pump module, reduces conduction loss, improves system energy efficiency, and achieves the purpose of energy conservation and emission reduction. The control module controls the start and stop of the execution structure of the heat pump module and the switch of the bridgeless PFC rectifier module, thereby realizing component integration and reducing the number and volume of circuit components.

[0028] (2) The air-source heat pump system provided by the utility model adopts a DSP chip as the control module to control the switch of the bridgeless PFC rectifier module and the start and stop of the execution structure of the heat pump module. On the basis of meeting the control requirements, one chip can be used for multiple purposes, further achieving the purpose of reducing the number and volume of circuit components, thereby reducing the volume of the product.

[0029] (3) In the air-energy heat pump system provided by the utility model, the first high-frequency power tube and the second high-frequency power tube in the bridgeless PFC rectifier module adopt silicon carbide MOS tubes. Compared with silicon MOS and IGBT, they have the advantages of small on-resistance, high switching frequency, and small switching loss, thereby improving the system operating frequency. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings are part of the present invention and are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention, but do not constitute an improper limitation on the present invention. Obviously, the accompanying drawings described below are only some embodiments. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work. In the accompanying drawings:

[0031] Figure 1 It is a bridge PFC circuit topology diagram in the prior art;

[0032] Figure 2 is a schematic diagram of an air energy heat pump system according to an exemplary embodiment of the present utility model;

[0033] Figure 3 is a circuit topology diagram of a bridgeless PFC rectifier module according to an exemplary embodiment of the utility model.

[0034] In the figure: 1', bridge rectifier; 2', filter; 3', energy storage capacitor; 4', switching device.

[0035] 100. heat pump module; 101. fan; 102. compressor; 103. other electrical actuators;

[0036] 200, control system; 201, bridgeless PFC rectifier module; 202, control module;

[0037] 300, embedded controller;

[0038] 1. The third capacitor; 2. The common mode inductor; 3. The filter capacitor; 4. The discharge resistor; 5. The first capacitor; 6. The second capacitor; 7. The reactor; 8. The first high-frequency power tube; 9. The second high-frequency power tube; 10. The first low-frequency diode; 11. The second low-frequency diode; 12. The absorption capacitor; 13. The film capacitor.

[0039] It should be noted that these drawings and textual descriptions are not intended to limit the conceptual scope of the present invention in any way, but rather to illustrate the concept of the present invention for those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solutions and advantages of the embodiments of the utility model clearer, the technical solutions in the embodiments will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. The following embodiments are used to illustrate the utility model but are not used to limit the scope of the utility model.

[0041] In the description of the present invention, it should be noted that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0042] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] Figure 1The figure shows a topology diagram of a bridge PFC circuit in the prior art.

[0044] like Figure 1 As shown, the bridge PFC circuit includes a bridge rectifier 1', a filter 2', an energy storage capacitor 3', a switch device 4' and a control circuit (not shown).

[0045] The input power of the bridge PFC circuit is AC power, which is first converted into DC power by a bridge rectifier 1'. The bridge rectifier 1' consists of four diodes and can convert the negative half cycle of the input voltage into a positive half cycle.

[0046] The filter 2' is arranged after the DC circuit outputted by the bridge rectifier 1', and is used to smooth the output voltage of the bridge rectifier 1'. As an example, the filter 2' generally includes an inductor and a capacitor, which can remove ripples on the DC circuit, thereby making the output voltage more stable.

[0047] The energy storage capacitor 3' is arranged after the filter 2', and has a large capacitance, and is used to store energy and provide it to the load. The energy storage capacitor 3' can absorb the power of the power grid when it is charged, and release energy when the load needs it.

[0048] The switch device 4' adjusts the output current by controlling the switching time ratio. The switch device 4' is the core device of the bridge PFC circuit, generally composed of MOSFET or IGBT and diode. Specifically, in each AC cycle, the switch device 4' switches at a fixed frequency and adjusts the output current by controlling the duty cycle.

[0049] The control circuit is used to generate the switching signal and monitor the parameters such as input current and output voltage. The control circuit can correct the power factor by comparing and adjusting the switching signal according to the feedback signals of input current and output voltage.

[0050] When the bridge PFC circuit is used for AC-DC conversion, two diodes in the bridge rectifier 1' participate in the loop in the positive and negative half cycles of the AC input. Therefore, there are both diode voltage drop losses and reverse recovery losses during this period, which is not conducive to improving system energy efficiency.

[0051] Based on this, the utility model provides a control system for an air energy heat pump system, including a bridgeless PFC rectifier module and a control module. Among them, one end of the bridgeless PFC rectifier module is configured to be connected to the heat pump module, and the other end is configured to be connected to the AC access end for AC-DC conversion. The control module is respectively connected to the heat pump module and the bridgeless PFC rectifier module, and is configured to control the start and stop of the execution structure of the heat pump module and the switch of the bridgeless PFC rectifier module. In this way, by using a bridgeless PFC rectifier module to perform AC-DC conversion and provide a DC voltage for the heat pump module, the number and volume of circuit components can be reduced, the conduction loss can be reduced, the energy efficiency of the system can be improved, and the purpose of energy saving and emission reduction can be achieved.

[0052] Figure 2 The structure of an air energy heat pump system according to an exemplary embodiment of the utility model is shown.

[0053] like Figure 2 As shown, the air energy heat pump system includes a heat pump module 100 and a control system 200 for the air energy heat pump system according to the above, and the control module 202 is connected to the heat pump module 100 and the bridgeless PFC rectifier module 201. The heat pump module 100 includes an execution structure composed of components such as a fan 101, an evaporator, a compressor 102, a condenser and an expansion valve. Taking the fan 101 and the compressor 102 as an example, the fan 101 is configured with a DC / AC fan drive circuit for driving the fan 101 to operate, and the compressor 102 is configured with a DC / AC compressor drive circuit for driving the compressor 102 to operate. The control module 202 is connected to the DC / AC fan drive circuit and the DC / AC compressor drive circuit to send control instructions to the DC / AC fan drive circuit and the DC / AC compressor drive circuit.

[0054] The output end of the bridgeless PFC rectifier module 201 is connected to the DCLink end, and the DCLink end is respectively connected to the input end of the DC / AC fan drive circuit and the input end of the DC / AC compressor drive circuit, so as to provide power for the fan 101 and the compressor 102 .

[0055] It should be noted that the air energy heat pump system also includes other electrical actuators 103 not shown, and the other electrical actuators 103 are electrically connected to the embedded controller 300, and the embedded controller 300 can be connected to the control module 202 via a 485 bus.

[0056] In some embodiments, the control module 202 adopts a DSP controller, so that a DSP chip can be used to control the switch of the bridgeless PFC rectifier module 201 and the start and stop of the execution structure of the heat pump module 100. On the basis of meeting the control requirements, one chip can be used for multiple purposes, further achieving the purpose of reducing the number and volume of circuit components, thereby reducing the volume of the product.

[0057] As an example, the DSP controller generates 14 PWM signals, of which 2 PWM signals are used to control the switch of the bridgeless PFC rectifier module 201, 6 PWM signals are used to control the on / off of the DC / AC fan drive circuit, and 6 PWM signals are used to control the on / off of the DC / AC compressor drive circuit.

[0058] Figure 3 The circuit topology diagram of the bridgeless PFC rectifier module 201 according to an exemplary embodiment of the present utility model is shown.

[0059] like Figure 3 As shown, the bridgeless PFC rectifier module 201 includes a preprocessing circuit and a bridgeless PFC circuit, wherein the preprocessing circuit is used to stabilize the input AC voltage; and the bridgeless PFC circuit is used to convert the stabilized AC voltage into a DC voltage.

[0060] As an example, the preprocessing circuit adopts a common mode filter, which includes a common mode inductor 2, a first capacitor 5 and a second capacitor 6. The input end of the common mode inductor 2 is connected to the AC input end, one end of the first capacitor 5 is connected to an output end of the common mode inductor 2, the other end of the first capacitor 5 is grounded, one end of the second capacitor 6 is connected to the other output end of the common mode inductor 2, and the other end of the second capacitor 6 is grounded. The first capacitor 5 and the second capacitor 6 are used to suppress common mode noise.

[0061] The common mode inductor 2 is composed of two sets of first windings and second windings with the same number of turns. The two windings are distributed on opposite sides of the magnetic ring. The magnetic fluxes generated by the currents in the first winding and the second winding are equal in magnitude and opposite in direction. The two magnetic fluxes cancel each other out and put the magnetic core in an unbiased state.

[0062] Furthermore, a third capacitor 1 for suppressing differential mode noise is provided between the input end of the common mode inductor 2 and the AC input end.

[0063] Furthermore, a filter capacitor 3 and a discharge resistor 4 are arranged in parallel between the output end of the common mode inductor 2 and one end of the first capacitor 5 and the second capacitor 6 to avoid residual voltage and ensure the safety of the system. It should be pointed out that the resistance value of the discharge resistor 4 should meet the design requirements, that is, the residual voltage should be reduced to below the preset value within the specified time.

[0064] In some embodiments, the bridgeless PFC circuit includes a reactor 7, a first high-frequency power tube 8, a second high-frequency power tube 9, a first low-frequency diode 10, a second low-frequency diode 11, and an output capacitor. One end of the reactor 7 is connected to one end of the first capacitor 5, and the other end is connected to the first high-frequency power tube 8 and the second high-frequency power tube 9. The control ends of the first high-frequency power tube 8 and the second high-frequency power tube 9 are connected to the control module 202. The output capacitor is connected to the first low-frequency diode 10 and the second low-frequency diode 11. It should be noted that the control module 202 is connected to the first high-frequency power tube 8 and the second high-frequency power tube 9 through a rectifier drive circuit to control the conduction and disconnection of the first high-frequency power tube 8 and the second high-frequency power tube 9.

[0065] In detail, when the AC input is in the positive half-cycle working cycle, the control module 202 controls the second high-frequency power tube 9 to turn on, the AC input passes through the second high-frequency power tube 9, the output end of the second high-frequency power tube 9 is connected to the input end through the second low-frequency diode 11, and the second low-frequency diode 11 starts to charge the reactor 7. The reactor 7 stores energy during the conduction phase of the second high-frequency power tube 9, and the load is powered by the output capacitor. When the second high-frequency power tube 9 ends conducting, the current flowing through the second high-frequency power tube 9 is transferred to the parasitic body diode of the first high-frequency power tube 8. The parasitic body diode and the second low-frequency diode 11 constitute the freewheeling path of the reactor 7, the voltage of the reactor 7 is reversed, the reactor 7 releases electric energy, and the reactor 7 and the AC input jointly provide electric energy to the output capacitor and the load.

[0066] When the AC input is in the negative half-cycle working cycle, the control module 202 controls the first high-frequency power tube 8 to be turned on, and the AC input passes through the first high-frequency power tube 8, and the output end of the first high-frequency power tube 8 is connected to the input end through the first low-frequency diode 10. The first low-frequency diode 10 starts to reversely charge the reactor 7, and the reactor 7 stores energy during the conduction stage of the first high-frequency power tube 8, and the load is powered by the output capacitor. When the first high-frequency power tube 8 is turned on, the current flowing through the first high-frequency power tube 8 is transferred to the parasitic body diode of the second high-frequency power tube 9, which and the first low-frequency diode 10 constitute the freewheeling path of the reactor 7, and the voltage at both ends of the reactor 7 is reversed, and the reactor 7 releases electric energy. The reactor 7 and the AC input jointly supply energy to the output capacitor and the load.

[0067] In other words, in the positive half cycle of the AC input, the second high-frequency power tube 9 is in a high-frequency on and off state, and the second low-frequency diode 11 is always in a forward on state. In the negative half cycle of the input, the first high-frequency power tube 8 is in a high-frequency on and off state, and the first low-frequency diode 10 is always in a forward on state.

[0068] In some embodiments, the first high-frequency power tube 8 and the second high-frequency power tube 9 are silicon carbide MOS tubes. Silicon carbide MOS tubes have the advantages of small on-resistance, high switching frequency, and small switching loss, which is beneficial to further reduce conduction loss and improve system energy efficiency.

[0069] In some implementations, the output capacitor includes an absorption capacitor 12 and a film capacitor 13 connected in parallel, which prolongs the service life of the bridgeless PFC rectifier module 201 .

[0070] The above is only a preferred embodiment of the present invention, and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the present invention can make some changes or modifications to equivalent embodiments of equivalent changes using the above-mentioned technical contents without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the present invention.

Claims

1. A control system for an air energy heat pump system, characterized in that: include: A bridgeless PFC rectifier module, one end of which is configured to be connected to the heat pump module, and the other end of which is configured to be connected to the AC access terminal for performing AC-DC conversion; The control module is connected to the heat pump module and the bridgeless PFC rectifier module respectively, and is configured to control the start and stop of the execution structure of the heat pump module and the switch of the bridgeless PFC rectifier module.

2. The control system for an air energy heat pump system according to claim 1, characterized in that: The bridgeless PFC rectifier module comprises: A pre-processing circuit for stabilizing the input AC voltage; The bridgeless PFC circuit is used to convert the stabilized AC voltage into a DC voltage.

3. The control system for an air energy heat pump system according to claim 2, characterized in that: The pre-processing circuit includes a common mode inductor, a first capacitor and a second capacitor; Among them, the input end of the common-mode inductor is connected to the AC access end, one end of the first capacitor is connected to an output end of the common-mode inductor, the other end of the first capacitor is grounded, one end of the second capacitor is connected to the other output end of the common-mode inductor, and the other end of the second capacitor is grounded.

4. The control system for an air energy heat pump system according to claim 3, characterized in that: A filter capacitor and a discharge resistor are arranged in parallel between the output end of the common mode inductor and one end of the first capacitor and the second capacitor.

5. The control system for an air energy heat pump system according to claim 3, characterized in that: A third capacitor for suppressing differential mode noise is also arranged between the input end of the common mode inductor and the AC access end.

6. The control system for an air energy heat pump system according to any one of claims 2 to 5, characterized in that: The bridgeless PFC circuit includes a reactor, a first high-frequency power tube, a second high-frequency power tube, a first low-frequency diode, a second low-frequency diode and an output capacitor; Wherein, one end of the reactor is connected to the preprocessing circuit, and the other end is connected to the first high-frequency power tube and the second high-frequency power tube; The control ends of the first high-frequency power tube and the second high-frequency power tube are connected to the control module; Two ends of the output capacitor are respectively connected to a connection node between the first high-frequency power tube and the first low-frequency diode, and a connection node between the second high-frequency power tube and the second low-frequency diode.

7. The control system for an air energy heat pump system according to claim 6, characterized in that: The output capacitor includes an absorption capacitor and a film capacitor which are arranged in parallel.

8. The control system for an air energy heat pump system according to claim 6, characterized in that: The first high-frequency power tube and the second high-frequency power tube are silicon carbide MOS tubes.

9. An air energy heat pump system, characterized in that: comprising a control system for an air energy heat pump system according to any one of claims 1 to 8; Also included is a heat pump module; The heat pump module is connected to the control module and the bridgeless PFC rectifier module.

10. An air energy heat pump water heater, characterized in that: Comprising the air energy heat pump system according to claim 9.

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