Multi-temperature-zone heat supply drying system based on heat pump

Abstract

The invention discloses a multi-temperature-zone heat supply drying system based on a heat pump, relates to the technical field of heat pump drying, and aims at solving the problems that a traditional drying system is single in operation working condition, and the same system can only operate at one temperature working condition at the same time. The system comprises a heat pump area and a drying area, the heat pump area comprises a compression condensation module and an evaporation area, the evaporation area comprises a plurality of evaporation modules connected in parallel, and a supercharging device is arranged between every two adjacent evaporation modules; the compression condensation module is further connected with a steam generation module of the drying area, the steam generation module is connected with a plurality of drying room areas, and evaporators of the evaporation module are arranged in the drying room areas. According to the multi-temperature-zone heat supply drying system based on the heat pump, the energy efficiency of the system is remarkably improved, the application range is wider, and the utilization rate is higher.

Description

Technical Field

[0001] The present invention relates to the technical field of heat pump drying, and in particular to a multi-temperature zone heating and drying system based on a heat pump. Background Art

[0002] Drying systems using heat pump technology are now commonplace. However, traditional drying systems operate under a single operating condition, meaning each system can only operate at one temperature at a time. This is because traditional heat pumps cannot simultaneously utilize multiple heat sources. Even if they heat drying systems at different temperatures simultaneously, the heat pump system cannot simultaneously dehumidify them, requiring the addition of an additional dehumidification system, increasing equipment investment costs.

[0003] The Chinese patent with publication number CN116951914A mainly involves real-time monitoring and remote control of drying equipment. Its equipment improvement cannot meet the needs of multiple heat source scenarios and cannot solve the above-mentioned technical problems. Summary of the Invention

[0004] The present invention solves the problem that the traditional drying system has a single operating condition and the same system can only operate at one temperature condition at the same time. It proposes a multi-temperature zone heating and drying system based on a heat pump, which significantly improves the system energy efficiency, has a wider range of applications, and has higher availability.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solution: a multi-temperature zone heating and drying system based on a heat pump, characterized in that it includes a heat pump area and a drying area, the heat pump area includes a compression and condensing module and an evaporation area, the evaporation area includes several parallel evaporation modules, and a boosting device is provided between adjacent evaporation modules; the compression and condensing module is also connected to the steam generation module of the drying area, the steam generation module is connected to several drying room areas, and the evaporator of the evaporation module is arranged inside the drying room area.

[0006] In this technical solution, the heat pump has a high-temperature evaporation heat absorption steam production mode, a medium-temperature evaporation heat absorption hot water production mode, a low-temperature evaporation heat absorption hot water production mode, a high-temperature evaporation-medium-temperature evaporation combined heat absorption steam production mode, a high-temperature evaporation-medium-temperature evaporation-low-temperature evaporation combined heat absorption steam production mode, a high-temperature evaporation-low-temperature evaporation combined heat absorption steam production mode, and a medium-temperature evaporation-low-temperature evaporation combined heat absorption hot water production mode. The system drying modes include steam heating drying, medium-temperature heating drying, low-temperature heating drying, steam heating-medium-temperature heating combined drying, steam heating-medium-temperature heating-low-temperature heating combined drying, steam heating-low-temperature heating combined drying, and medium-temperature heating-low-temperature heating combined drying. The system of this technical solution realizes cascade energy utilization from steam to liquid water. The system also has multiple drying modes and a high degree of integration. While being more energy-efficient than traditional drying systems, it also has higher applicability and availability.

[0007] The present invention is further configured as follows: the compression condensing module includes a first compressor and a condenser connected to each other, the end of the condenser away from the first compressor is connected to an economizer, and the economizer is respectively connected to a second electronic expansion valve and an inlet end of the evaporation area.

[0008] In this technical solution, the low-temperature, low-pressure superheated gas passes through the gas-liquid separator and the first compressor in sequence, becoming a high-temperature, high-pressure gas, then enters the condenser to absorb heat and cool down, becoming a medium-temperature, high-pressure liquid, then enters the economizer to further absorb heat and cool down, and finally enters the evaporation area, and returns to the first compressor through the second electronic expansion valve throttling.

[0009] The present invention is further configured as follows: the evaporation module includes a high-temperature evaporation module, a medium-temperature evaporation module and a low-temperature evaporation module, each evaporation module includes an evaporator and an electronic expansion valve connected to the evaporator, and a solenoid valve is provided between the evaporator and the first compressor.

[0010] In this technical solution, the above-mentioned high-temperature evaporation module, medium-temperature evaporation module and low-temperature evaporation module can all be connected to the compression condensation module, and different heat pump modes can be switched by opening and closing the corresponding solenoid valves.

[0011] The present invention is further configured as follows: the boosting device is a boosting pump, a first boosting pump is provided between the high-temperature evaporation module and the medium-temperature evaporation module, and a second boosting pump is provided between the medium-temperature evaporation module and the low-temperature evaporation module.

[0012] In this technical solution, a multi-stage boosting method of a booster pump is adopted to solve the problem that heat from different heat sources is difficult to utilize simultaneously.

[0013] The present invention is further configured as follows: the steam generation module includes a steam generator, the steam generator is respectively connected to a second water pump and a steam pump, a first electric heater is provided in the steam generator, the steam generator is connected to the compression and condensing module through the second water pump, and the steam pump and the steam generator are both connected to a waste heat exchanger.

[0014] In this technical solution, the steam generation module can generate steam and can cooperate with the drying room area to provide different types of system drying modes.

[0015] The present invention is further configured such that: the drying room area includes a steam heating area, a medium temperature heating area and a low temperature heating area, and different drying room areas can work in conjunction with each other.

[0016] In this technical solution, steam heating and drying are used when the drying temperature is ≥100°C, medium-temperature heating and drying are used when the drying temperature is between 100°C and 75°C, and low-temperature heating and drying are used when the drying temperature is between 75°C and 40°C. All modes have a preheating phase and a normal operation phase.

[0017] The present invention is further configured as follows: the steam heating area includes a first drying room and a first air heater in the first drying room, the inlet end of the first air heater is connected to a second electric heater, the other end of the second electric heater is connected to a regulating compression module, the outlet end of the first air heater is connected to an expansion and a third water pump, and the third water pump and the expansion are both connected to a waste heat exchanger.

[0018] In this technical solution, in more detail, a first one-way valve is provided between the third water pump and the waste heat exchanger.

[0019] The present invention is further configured as follows: the medium-temperature heating area includes a second drying room and a second air heater in the second drying room, the inlet end of the second air heater is connected to a first water pump, the first water pump is connected to a steam generator, and the outlet end of the second air heater is connected to the waste heat exchanger after being guided by a one-way valve.

[0020] In this technical solution, in more detail, a fifth one-way valve and a ninth solenoid valve are sequentially arranged between the first water pump and the second air heater, and a third one-way valve, an eleventh solenoid valve and a fourth one-way valve are sequentially arranged between the second air heater and the waste heat exchanger.

[0021] The present invention is further configured as follows: the low-temperature heating area includes a third drying room and a third air heater in the third drying room, the inlet end of the third air heater is connected to the first water pump, and the outlet end of the third air heater is connected to the waste heat exchanger.

[0022] In the present technical solution, in more detail, a tenth solenoid valve, a twelfth solenoid valve and a seventh one-way valve are sequentially arranged between the third air heater and the first water pump, and the inlet end of the seventh one-way valve is connected to the inlet end of the fifth one-way valve; a sixth one-way valve and a fourth one-way valve are sequentially arranged between the third air heater and the waste heat exchanger, that is, overlapping with part of the medium-temperature heating area.

[0023] The present invention is further configured as follows: the regulating and compression module includes a seventh solenoid valve and a water vapor compressor connected to the seventh solenoid valve, and the seventh solenoid valve and the water vapor compressor are also connected in parallel with an eighth solenoid valve; one end of the seventh solenoid valve is connected to the steam generator, and the other end of the water vapor compressor is connected to the second electric heater.

[0024] In this technical solution, if the heating requires superheated steam with a pressure greater than normal pressure, the eighth solenoid valve is closed and the seventh solenoid valve is opened. The saturated steam is pressurized to the set pressure by the water vapor compressor and then enters the second electric heater. If there are certain requirements for the water vapor temperature, the second electric heater is started; if there are no requirements for the heating steam pressure, the seventh solenoid valve is closed and the eighth solenoid valve is opened. The saturated steam enters the second electric heater. If there are certain requirements for the water vapor temperature, the second electric heater is started.

[0025] The present invention can bring the following beneficial effects: The present invention relates to a multi-temperature zone heating and drying system based on a heat pump. The heating system realizes cascade utilization of energy from steam to liquid water. The system has multiple drying modes and a high degree of integration. Compared with traditional drying systems, it is more energy-efficient, has wider applicability, and has a higher utilization rate. The use of a multi-stage boosting method with a booster pump solves the problem of difficulty in simultaneously utilizing heat from different heat sources, solves the dehumidification problem of the medium and low temperature drying system, and improves the energy efficiency of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is an overall schematic diagram of the multi-temperature zone heating and drying system based on a heat pump in this application.

[0027] Figure 2 This is a schematic diagram of the heat pump mode of the multi-temperature zone heating and drying system based on the heat pump in this application.

[0028] Reference numerals: First solenoid valve 1, second solenoid valve 2, third solenoid valve 3, first booster pump 4, fourth solenoid valve 5, second booster pump 6, fifth solenoid valve 7, first compressor 8, first drying room 9, first evaporator 10, first electronic expansion valve 11, second electronic expansion valve 12, economizer 13, condenser 14, first air heater 15, sixth solenoid valve 16, second drying room 17, second evaporator 18, third solenoid expansion valve 19, second air heater 20, third drying room 21, third evaporator 22, fourth electronic expansion valve 23, third air heater 24, first water pump 25, steam generator generator 26, seventh solenoid valve 27, water vapor compressor 28, steam pump 29, eighth solenoid valve 30, second water pump 31, first electric heater 32, second electric heater 33, waste heat exchanger 34, expansion 35, third water pump 36, first one-way valve 37, fourth water pump 38, second one-way valve 39, third one-way valve 40, fourth one-way valve 41, ninth solenoid valve 42, fifth one-way valve 43, sixth one-way valve 44, tenth solenoid valve 45, seventh one-way valve 46, gas-liquid separator 47, liquid storage tank 48, eleventh solenoid valve 49, twelfth solenoid valve 50, thirteenth solenoid valve 51. DETAILED DESCRIPTION

[0029] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific implementation method described herein is only an optimal embodiment of the present invention, which is only used to explain the present invention and does not limit the scope of protection of the present invention. All other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0030] Example 1 This embodiment proposes a multi-temperature zone heating and drying system based on a heat pump. Figure 1 It mainly includes a heat pump area and a drying area. The heat pump area mainly includes a compression condensing module and an evaporation area. The evaporation area mainly includes several evaporation modules connected in parallel, and a boosting device is arranged between adjacent evaporation modules; the compression condensing module is also connected to the steam generating module in the drying area, and the steam generating module is connected to several drying room areas. The evaporator of the evaporation module is arranged inside the drying room area.

[0031] In this embodiment, reference Figure 2 The heat pump has a high-temperature evaporation heat absorption steam making mode, a medium-temperature evaporation heat absorption hot water making mode, a low-temperature evaporation heat absorption hot water making mode, a high-temperature evaporation-medium-temperature evaporation combined heat absorption steam making mode, a high-temperature evaporation-medium-temperature evaporation-low-temperature evaporation combined heat absorption steam making mode, a high-temperature evaporation-low-temperature evaporation combined heat absorption steam making mode, and a medium-temperature evaporation-low-temperature evaporation combined heat absorption hot water making mode.

[0032] The system's drying modes include steam heating, medium-temperature heating, low-temperature heating, combined steam-medium-temperature drying, combined steam-medium-temperature-low-temperature drying, combined steam-low-temperature drying, and combined medium-temperature-low-temperature drying. Steam heating is used for drying temperatures ≥ 100°C, medium-temperature heating is used for drying temperatures between 100°C and 75°C, and low-temperature heating is used for drying temperatures between 75°C and 40°C. All modes have a preheating phase and a normal operating phase.

[0033] refer to Figure 1 The compression-condensing module includes a first compressor 8 and a condenser 14 connected to each other. The end of the condenser 14, away from the first compressor 8, is connected to an economizer 13. The economizer 13 is connected to the second electronic expansion valve 12 and the inlet of the evaporation region. The first compressor 8 is also connected to a gas-liquid separator 47. The other end of the gas-liquid separator 47 is connected to both the third solenoid valve 3 and the first solenoid valve 1.

[0034] In this technical solution, the low-temperature, low-pressure superheated gas passes through the gas-liquid separator 47 and the first compressor 8 in sequence, becoming a high-temperature, high-pressure gas, and then enters the condenser 14 to absorb heat and cool down, becoming a medium-temperature, high-pressure liquid, and then enters the economizer 13 to further absorb heat and cool down, and finally enters the evaporation area, and returns to the first compressor 8 through the second electronic expansion valve 12 for throttling.

[0035] The evaporation modules include a high-temperature evaporation module, a medium-temperature evaporation module and a low-temperature evaporation module. Each evaporation module includes an evaporator connected to an electronic expansion valve. A solenoid valve is provided between the evaporator and the first compressor 8 .

[0036] In this technical solution, the above-mentioned high-temperature evaporation module, medium-temperature evaporation module and low-temperature evaporation module can all be connected to the compression condensation module, and different heat pump modes can be switched by opening and closing the corresponding solenoid valves.

[0037] In more detail, the high-temperature evaporation module includes a first electronic expansion valve 11, one end of the first electronic expansion valve 11 is connected to the first evaporator 10, the other end of the first electronic expansion valve 11 is connected to the economizer 13 of the compression condensing module, the other end of the first evaporator 10 is connected to the third solenoid valve 3, and the other end of the third solenoid valve 3 is connected to the first compressor 8; the above-mentioned first evaporator 10 is arranged in the first drying room 9.

[0038] The medium-temperature evaporation module includes a third electronic expansion valve 19, one end of which is connected to the second evaporator 18. The other end of the second evaporator 18 is connected to the sixth solenoid valve 16. The other end of the sixth solenoid valve 16 is connected to the first booster pump 4 of the boosting device. The other end of the first booster pump 4 is connected to one end of the third solenoid valve 3. A fourth solenoid valve 5 is also located and connected between the first booster pump 4 and the sixth solenoid valve 16. Furthermore, the other end of the sixth solenoid valve 16 is separately connected to the first solenoid valve 1, and the other end of the first solenoid valve 1 is directly connected to the first compressor 8. The second evaporator 18 is located in the second drying room 17.

[0039] The low-temperature evaporation module includes a fourth electronic expansion valve 23. One end of the fourth electronic expansion valve 23 is connected to the third evaporator 22. The other end of the third evaporator 22 is respectively connected to the second solenoid valve 2 and the fifth solenoid valve 7. The other end of the fifth solenoid valve 7 is connected to the second booster pump 6 of the boosting device. The other end of the second booster pump 6 is connected to the fourth solenoid valve 5. The other end of the second solenoid valve 2 is respectively connected to the other ends of the first solenoid valve 1 and the sixth solenoid valve 16. The third evaporator 22 is disposed in the third drying chamber 21.

[0040] The boosting device is a boosting pump. A first boosting pump 4 is provided between the high-temperature evaporation module and the medium-temperature evaporation module, and a second boosting pump is provided between the medium-temperature evaporation module and the low-temperature evaporation module.

[0041] In this technical solution, a multi-stage boosting method of a booster pump is adopted to solve the problem that heat from different heat sources is difficult to utilize simultaneously.

[0042] In the high-temperature evaporation heat absorption steam production mode, the third solenoid valve 3 is opened, and the refrigerant in the low-temperature, low-pressure saturated state absorbs heat through the first evaporator 10, becomes a low-temperature, low-pressure superheated gas, passes through the gas-liquid separator 47, and then enters the first compressor 8, becomes a high-temperature, high-pressure gas, and then enters the condenser 14 to absorb heat and cool down, becoming a medium-temperature, high-pressure liquid, and then enters the economizer 13 to further absorb heat and cool down, and then is divided into two paths, one path enters the first electronic expansion valve 11, and then continues the previous cycle, the other path is throttled by the second electronic expansion valve 12, and then enters the economizer 13, becomes a superheated gas and enters the first compressor 8, and continues to be compressed after mixing with the compressed gas from the other path, and continues the subsequent cycle.

[0043] In the medium-temperature evaporation heat absorption water heating mode, the first solenoid valve 1 and the sixth solenoid valve 16 are opened, and the refrigerant in the low-temperature, low-pressure saturated state absorbs heat through the second evaporator 18, becomes a low-temperature, low-pressure superheated gas, passes through the gas-liquid separator 47, and then enters the first compressor 8, becomes a high-temperature, high-pressure gas, and then enters the condenser 14 to absorb heat and cool down, becoming a medium-temperature, high-pressure liquid, and then enters the economizer 13 to further absorb heat and cool down, and then is divided into two paths, one path enters the third electromagnetic expansion valve 19, and then continues the previous cycle, the other path is throttled by the second electronic expansion valve 12, and then enters the economizer 13, becomes a superheated gas and enters the first compressor 8, and continues to be compressed after mixing with the compressed gas from the other path, and continues the subsequent cycle.

[0044] In the low-temperature evaporation heat absorption water heating mode, the second solenoid valve 2 is opened, and the refrigerant in the low-temperature, low-pressure saturated state absorbs heat through the third evaporator 22, becomes a low-temperature, low-pressure superheated gas, passes through the gas-liquid separator 47, and then enters the first compressor 8, becomes a high-temperature, high-pressure gas, and then enters the condenser 14 to absorb heat and cool down, becoming a medium-temperature, high-pressure liquid, and then enters the economizer 13 to further absorb heat and cool down, and then is divided into two paths, one path enters the fourth electronic expansion valve 23, and then continues the previous cycle, the other path is throttled by the second electronic expansion valve 12, and then enters the economizer 13, becomes a superheated gas and enters the first compressor 8, and continues to be compressed after mixing with the compressed gas from the other path, and continues the subsequent cycle.

[0045] In addition, a high-temperature evaporation-medium-temperature evaporation combined heat absorption steam production mode is also included. In this mode, the third solenoid valve 3, the fourth solenoid valve 5, and the sixth solenoid valve 16 are open. The medium-temperature and high-pressure liquid refrigerant enters the economizer 13 and is further absorbed heat and cooled. It is then divided into three paths. The first path enters the first electronic expansion valve 11 and is throttled, and then enters the first evaporator 10 to absorb heat and become superheated gas; the second path is throttled by the second electronic expansion valve 12, and then enters the economizer 13, becomes superheated gas and enters the first compressor 8; the third path is throttled by the third electromagnetic expansion valve 19, and then enters the second evaporator 18 to absorb heat and become superheated gas, and is then pressurized by the first booster pump 4 until the pressure is the same as the refrigerant at the outlet of the first evaporator 10, that is, the first path refrigerant, and then mixed with the refrigerant and enters the gas-liquid separator 47, enters the first compressor 8 for compression, and mixes with the refrigerant at the outlet of the economizer 13, that is, the second path refrigerant, and continues to be compressed by the first compressor 8, and then enters the condenser 14 to absorb heat and cool down, becoming a medium-temperature and high-pressure liquid, and finally enters the economizer 13, divided into three paths, and continues the previous cycle.

[0046] It also includes a high-temperature evaporation-medium-temperature evaporation-low-temperature evaporation combined heat absorption steam production mode. In this mode, the third solenoid valve 3, the fourth solenoid valve 5, the sixth solenoid valve 16, and the fifth solenoid valve 7 are open. The medium-temperature and high-pressure liquid refrigerant enters the economizer 13 to further absorb heat and cool down, and then is divided into four paths. The first path enters the first electronic expansion valve 11 and is throttled, and then enters the first evaporator 10 to absorb heat and become superheated gas; the second path is throttled by the second electronic expansion valve 12, and then enters the economizer 13, becomes superheated gas and then enters the first compressor 8; the third path is throttled by the third solenoid expansion valve 19, and then enters the second evaporator 18 to absorb heat and become superheated gas; the fourth path is throttled by the fourth electronic expansion valve 23, and then enters the third evaporator 22 to absorb heat and become superheated gas, and then is throttled by the second The booster pump 6 pressurizes the refrigerant until it reaches the same pressure as the refrigerant at the outlet of the second evaporator 18, i.e., the third refrigerant, and mixes with it. The refrigerant then enters the first booster pump 4, where it is pressurized to the same pressure as the refrigerant at the outlet of the first evaporator 10, i.e., the first refrigerant, and mixes with it. The refrigerant then enters the gas-liquid separator 47, and then enters the first compressor 8 for compression, and mixes with the refrigerant at the outlet of the economizer 13, i.e., the second refrigerant. The refrigerant continues to be compressed by the first compressor 8, and then enters the condenser 14 to absorb heat and cool down, becoming a medium-temperature high-pressure liquid. The refrigerant finally enters the economizer 13, where it is divided into four routes and continues the previous cycle.

[0047] In the combined high-temperature evaporation and low-temperature evaporation heat absorption steam production mode, the first solenoid valve 1, the third solenoid valve 3, and the fifth solenoid valve 7 are open. The medium-temperature, high-pressure liquid refrigerant enters the economizer 13, where it absorbs heat and cools down. It then splits into three paths: the first path enters the first electronic expansion valve 11, where it is throttled, and then enters the first evaporator 10, where it absorbs heat and becomes superheated gas. The second path is throttled by the second electronic expansion valve 12, then enters the economizer 13, where it becomes superheated gas before entering the first compressor 8. The third path is throttled by the fourth electronic expansion valve 23, then enters the third evaporator 22, where it absorbs heat and becomes superheated gas. It is then pressurized by the second booster pump 6 until its pressure reaches the same level as the refrigerant at the outlet of the first evaporator 10, i.e., the first path, where it mixes with the refrigerant at the outlet of the first evaporator 10. It then enters the gas-liquid separator 47, is compressed by the first compressor 8, and mixes with the refrigerant at the outlet of the economizer 13, i.e., the second path. It then enters the condenser 14, where it absorbs heat and cools down, becoming a medium-temperature, high-pressure liquid. Finally, it enters the economizer 13, splitting into three paths and continuing the previous cycle.

[0048] In the combined medium-temperature evaporation and low-temperature evaporation heat absorption water heating mode, the first solenoid valve 1, the sixth solenoid valve 16, and the fifth solenoid valve 7 are open. The medium-temperature, high-pressure liquid refrigerant enters the economizer 13, where it absorbs heat and cools down. It then splits into three paths: the first path enters the third solenoid expansion valve 19, where it is throttled, and then enters the second evaporator 18, where it absorbs heat and becomes superheated gas. The second path is throttled by the second electronic expansion valve 12, then enters the economizer 13, where it becomes superheated gas before entering the first compressor 8. The third path is throttled by the fourth electronic expansion valve 23, then enters the third evaporator 22, where it absorbs heat and becomes superheated gas. It is then pressurized by the second booster pump 6 until its pressure reaches the same level as the refrigerant at the outlet of the second evaporator 18, i.e., the third path, where it mixes with the refrigerant at the outlet of the second evaporator 18. It then enters the gas-liquid separator 47, is compressed by the first compressor 8, and mixes with the refrigerant at the outlet of the economizer 13, i.e., the second path. It then enters the condenser 14, where it absorbs heat and cools down, becoming a medium-temperature, high-pressure liquid. Finally, it enters the economizer 13, splitting into three paths and continuing the previous cycle.

[0049] Continue to refer Figure 1 The steam generation module includes a steam generator 26, which is connected to a second water pump 31 and a steam pump 29 respectively. A first electric heater 32 is provided in the steam generator 26. The steam generator 26 is connected to the compression and condensing module through the second water pump 31. The steam pump 29 and the steam generator 26 are both connected to a waste heat exchanger 34.

[0050] In this technical solution, the steam generation module can generate steam and can cooperate with the drying room area to provide different types of system drying modes.

[0051] The drying room area includes a steam heating area, a medium temperature heating area and a low temperature heating area, and different drying room areas can work together.

[0052] The inlet end of the first air heater 15 is connected to the second electric heater 33, the other end of the second electric heater 33 is connected to the regulating compression module, the outlet end of the first air heater 15 is connected to the expansion 35 and the third water pump 36, and the third water pump 36 and the expansion 35 are both connected to the waste heat exchanger 34.

[0053] In this technical solution, in more detail, a first one-way valve 37 is provided between the third water pump 36 and the waste heat exchanger 34 .

[0054] In the steam heating drying mode, there are a preheating stage and an operation stage.

[0055] Preheating stage: The second water pump 31 and the first electric heater 32 are started, and the eighth solenoid valve 30 is opened until steam is generated in the steam generator 26, and then the steam pump 29 is started.

[0056] Operational Phase: The heat pump operates in a high-temperature evaporation and heat absorption steam production mode. Liquid water in the steam generator 26 enters the condenser 14 via the second water pump 31, where it is heated to above 100°C. It then enters the steam generator 26. Due to its volume expansion, the high-temperature liquid water produces 100°C saturated steam. If superheated steam with a pressure greater than atmospheric pressure is required for heating, the eighth solenoid valve 30 is closed and the seventh solenoid valve 27 is opened. The saturated steam is pressurized to a set pressure by the steam compressor 28 and then enters the second electric heater 33. If there is a specific steam temperature requirement, the second electric heater 33 is activated. If there is no specific steam pressure requirement for heating, the seventh solenoid valve 27 is closed and the eighth solenoid valve 30 is opened, allowing the saturated steam to enter the second electric heater 33. If there is a specific steam temperature requirement, the second electric heater 33 is activated. The steam enters the first air heater 15, heating the air in the first drying chamber 9. After cooling, the steam enters the expansion chamber 35. The steam passes through the third water pump 36 and enters the waste heat exchanger 34, where it exchanges heat with the exhaust steam discharged from the top of the expansion chamber 35. The steam and exhaust steam are then returned to the steam generator 26. The hot air in the first drying chamber 9 absorbs heat, cools down, and increases humidity by the drying material, and is then condensed and dehumidified by the first evaporator 10.

[0057] The medium-temperature heating area includes a second drying room 17 and a second air heater 20 in the second drying room 17. The inlet end of the second air heater 20 is connected to a first water pump 25, and the first water pump 25 is connected to a steam generator 26. The outlet end of the second air heater 20 is connected to the waste heat exchanger 34 after being guided by a one-way valve.

[0058] In the present technical solution, in more detail, a fifth one-way valve 43 and a ninth solenoid valve 42 are sequentially arranged between the first water pump 25 and the second air heater 20, and a third one-way valve 40, an eleventh solenoid valve 49 and a fourth one-way valve 41 are sequentially arranged between the second air heater 20 and the waste heat exchanger 34.

[0059] In the medium temperature heating and drying mode, there are a preheating stage and an operation stage.

[0060] Preheating stage: the second water pump 31, the first electric heater 32, and the first water pump 25 are started, and the ninth solenoid valve 42 and the eleventh solenoid valve 49 are opened until the water temperature in the steam generator 26 reaches 75°C.

[0061] Operational Phase: The heat pump operates in the medium-temperature evaporation and heat absorption hot water production mode. Liquid water in the steam generator 26 enters the condenser 14 via the second water pump 31, where it is heated and then returns to the steam generator 26. The liquid water passes through the first water pump 25 and the fifth one-way valve 43 before entering the second air heater 20, heating the air in the second drying chamber 17. After cooling, the liquid water passes through the third and fourth one-way valves 40 and 41, and then the waste heat exchanger 34, before returning to the steam generator 26. The hot air in the second drying chamber 17 absorbs heat, cools, and humidifies as it absorbs heat from the drying material. It is then condensed and dehumidified by the second evaporator 18.

[0062] The low-temperature heating area includes a third drying room 21 and a third air heater 24 in the third drying room. The inlet of the third air heater 24 is connected to the first water pump 25 , and the outlet of the third air heater 24 is connected to the waste heat exchanger 34 .

[0063] In the present technical solution, in more detail, a tenth solenoid valve 45, a twelfth solenoid valve 50 and a seventh one-way valve 46 are sequentially arranged between the third air heater 24 and the first water pump 25, and the inlet end of the seventh one-way valve 46 is connected to the inlet end of the fifth one-way valve 43; a sixth one-way valve 44 and a fourth one-way valve 41 are sequentially arranged between the third air heater 24 and the waste heat exchanger 34, that is, overlapping with part of the medium-temperature heating area.

[0064] In addition, the expansion valve 35 is also connected to a fourth water pump 38 , the other end of the fourth water pump 38 is connected to a second one-way valve 39 , the outlet end of the second one-way valve 39 is connected to a thirteenth solenoid valve 51 , and the thirteenth solenoid valve 51 is connected to the inlet end of the tenth solenoid valve 45 .

[0065] In the low-temperature heating drying mode, it includes a preheating stage and an operating stage.

[0066] Preheating stage: the second water pump 31, the first electric heater 32, and the first water pump 25 are started, and the tenth solenoid valve 45 and the twelfth solenoid valve 50 are opened until the water temperature in the steam generator 26 reaches 50°C.

[0067] Operational Phase: The heat pump operates in low-temperature evaporation and heat absorption hot water production mode. Liquid water in the steam generator 26 flows through the second water pump 31 into the condenser 14, where it is heated and then returns to the steam generator 26. The liquid water passes through the first water pump 25 and the seventh one-way valve 46 before entering the third air heater 24, heating the air in the third drying chamber 21. After cooling, the liquid water passes through the sixth one-way valve 44, the fourth one-way valve 41, and the waste heat exchanger 34, finally returning to the steam generator 26. The hot air in the third drying chamber 21 absorbs heat, cools, and humidifies as it absorbs heat from the drying material. It is then condensed and dehumidified by the third evaporator 22.

[0068] The regulating and compression module includes a seventh solenoid valve 27 and a water vapor compressor 28 connected to the seventh solenoid valve 27. The seventh solenoid valve 27 and the water vapor compressor 28 are also connected in parallel with an eighth solenoid valve 30; one end of the seventh solenoid valve 27 is connected to the steam generator 26, and the other end of the water vapor compressor 28 is connected to the second electric heater 33.

[0069] This embodiment also includes a steam heating-medium temperature heating combined drying mode. In this mode, the steam heating drying mode is first started, and then the drain in the drain 35 is sent to the second air heater 20 through the fourth water pump 38 to heat the air in the second drying room 17. The eleventh solenoid valve 49 is opened, and then the drain passes through the third one-way valve 40, the fourth one-way valve 41, and the waste heat exchanger 34 in sequence and returns to the steam generator 26. If the drain flow rate cannot meet the heating power of the second air heater 20, the first water pump 25 is used to supplement circulating water for heating. Finally, the heat pump operation mode is switched to the high-temperature evaporation-medium temperature evaporation combined heat absorption steam production mode.

[0070] In the steam heating-medium temperature heating-low temperature heating combined drying mode, the steam heating-medium temperature heating combined drying mode is first started, then the tenth solenoid valve 45 is opened, the eleventh solenoid valve 49 is closed, and the drain comes out of the second air heater 20 and enters the third air heater 24 to heat the air in the third drying room 21. Then the drain passes through the sixth one-way valve 44, the fourth one-way valve 41, and the waste heat exchanger 34 in sequence and returns to the steam generator 26. Finally, the heat pump operation mode is switched to the high-temperature evaporation-medium temperature evaporation-low temperature evaporation combined heat absorption steam production mode.

[0071] In the steam heating-low temperature heating combined drying mode, the steam heating drying mode is first started, and then the tenth solenoid valve 45, the twelfth solenoid valve 50, and the thirteenth solenoid valve 51 are opened, and the drain in the drain 35 is sent to the third air heater 24 through the fourth water pump 38 to heat the air in the third drying room 21, and then the drain passes through the sixth one-way valve 44, the fourth one-way valve 41, and the waste heat exchanger 34 in sequence and returns to the steam generator 26. If the drain flow rate cannot meet the heating power of the third air heater 24, the circulating water is supplemented by the first water pump 25 for heating. Finally, the heat pump operation mode is switched to the high-temperature evaporation-low temperature evaporation combined heat absorption steam production mode.

[0072] In the combined medium-temperature heating and low-temperature heating drying mode, the medium-temperature heating drying mode is first activated. Then, the tenth solenoid valve 45 is opened, allowing liquid water to enter the third air heater 24, heating the air in the third drying chamber 21. The liquid water then passes through the sixth and fourth one-way valves 44 and 41, and returns to the steam generator 26 through the waste heat exchanger 34. The heat pump then switches to the combined medium-temperature evaporation and low-temperature evaporation heat absorption water heating mode.

[0073] In this embodiment, the first compressor can be a scroll, screw, or centrifugal compressor, and the frequency can be changed according to the heating power demand of the drying room. The first booster pump 4 and the second booster pump 6 can be boosting equipment such as fluorine pumps and compressors.

[0074] Heat pump systems can use refrigerants such as R142b, R134a, R515b, R245fa, and R1233zd(E). If using refrigerants with similar temperature ranges, such as R142b, R134a, and R515b, the drying area can operate with medium-temperature heating, low-temperature heating, or a combination of medium- and low-temperature heating. If using refrigerants with similar temperature ranges, such as R245fa and R1233zd(E), the drying system can operate with steam heating, medium-temperature heating, low-temperature heating, a combination of steam heating and medium-temperature heating, a combination of steam heating and medium-temperature heating and low-temperature heating, a combination of steam heating and low-temperature heating, or a combination of medium- and low-temperature heating.

[0075] In this embodiment, there is no limit on the size of the multi-temperature zone heating and drying system based on the heat pump, and a heating power of 2kW~10MW can be achieved. The number of drying rooms can be increased or decreased according to demand.

[0076] Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions to the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention and are intended to be encompassed by the claims of the present invention.

Claims

1. A multi-temperature zone heating and drying system based on a heat pump, characterized in that: It includes a heat pump area and a drying area. The heat pump area includes a compression condensing module and an evaporation area. The evaporation area includes several parallel evaporation modules, and a boosting device is provided between adjacent evaporation modules; the compression condensing module is also connected to the steam generating module of the drying area, and the steam generating module is connected to several drying room areas. The evaporator of the evaporation module is arranged inside the drying room area.

2. The multi-temperature zone heating and drying system based on a heat pump according to claim 1 is characterized in that: The compression condensation module comprises a first compressor (8) and a condenser (14) connected to each other, wherein one end of the condenser (14) away from the first compressor (8) is connected to an economizer (13), and the economizer (13) is respectively connected to a second electronic expansion valve (12) and an inlet end of the evaporation region.

3. The multi-temperature zone heating and drying system based on a heat pump according to claim 2, characterized in that: The evaporation modules include a high-temperature evaporation module, a medium-temperature evaporation module, and a low-temperature evaporation module. Each evaporation module includes an evaporator and an electronic expansion valve connected to the evaporator. A solenoid valve is provided between the evaporator and the first compressor (8).

4. The multi-temperature zone heating and drying system based on a heat pump according to claim 3 is characterized in that: The boosting device is a boosting pump, a first boosting pump (4) is provided between the high-temperature evaporation module and the medium-temperature evaporation module, and a second boosting pump is provided between the medium-temperature evaporation module and the low-temperature evaporation module.

5. The multi-temperature zone heating and drying system based on a heat pump according to any one of claims 1 to 4, characterized in that: The steam generation module comprises a steam generator (26), the steam generator (26) being connected to a second water pump (31) and a steam pump (29), a first electric heater (32) being provided in the steam generator (26), the steam generator (26) being connected to a compression condensation module via the second water pump (31), and the steam pump (29) and the steam generator (26) being connected to a waste heat exchanger (34).

6. The multi-temperature zone heating and drying system based on a heat pump according to claim 5, characterized in that: The drying room area includes a steam heating area, a medium temperature heating area and a low temperature heating area, and different drying room areas can work in conjunction with each other.

7. The multi-temperature zone heating and drying system based on a heat pump according to claim 6, characterized in that: The steam heating area includes a first drying room (9) and a first air heater (15) in the first drying room (9), the inlet end of the first air heater (15) is connected to a second electric heater (33), the other end of the second electric heater (33) is connected to a regulating compression module, the outlet end of the first air heater (15) is connected to an expansion unit (35) and a third water pump (36), and the third water pump (36) and the expansion unit (35) are both connected to a waste heat exchanger (34).

8. The multi-temperature zone heating and drying system based on a heat pump according to claim 6 or 7, characterized in that: The medium-temperature heating area includes a second drying room (17) and a second air heater (20) in the second drying room (17). The inlet end of the second air heater (20) is connected to a first water pump (25), and the first water pump (25) is connected to a steam generator (26). The outlet end of the second air heater (20) is connected to a waste heat exchanger (34) after being guided by a one-way valve.

9. The multi-temperature zone heating and drying system based on a heat pump according to claim 6 or 7, characterized in that: The low-temperature heating area includes a third drying room (21) and a third air heater (24) in the third drying room, wherein the inlet end of the third air heater (24) is connected to the first water pump (25), and the outlet end of the third air heater (24) is connected to the waste heat exchanger (34).

10. The multi-temperature zone heating and drying system based on a heat pump according to claim 7, characterized in that: The regulating and compressing module comprises a seventh solenoid valve (27) and a water vapor compressor (28) connected to the seventh solenoid valve (27), and the seventh solenoid valve (27) and the water vapor compressor (28) are further connected in parallel with an eighth solenoid valve (30); one end of the seventh solenoid valve (27) is connected to the steam generator (26), and the other end of the water vapor compressor (28) is connected to the second electric heater (33).

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