Heat exchanger for two-stage cascade heat pump

Abstract

The invention discloses a heat exchanger for a two-stage cascade heat pump, and belongs to the technical field of heat pump exchangers, the heat exchanger comprises a case, the case is composed of a supporting frame, a machine bottom support, a protection plate, a machine top cover plate, a main control cabinet and an evaporator, a machine top sector is arranged above the evaporator, and a heat exchange unit is arranged below the evaporator; the heat exchange unit comprises a low-temperature-stage loop and a high-temperature-stage loop, deicing mechanisms are arranged on the two sides of the bottom of the evaporator, air supply mechanisms are arranged on the two sides of the heat exchange unit, and a jet fan is arranged on the outer side of the machine box. The jet fans generate strong cylindrical high-speed airflow, and a large amount of deposited cold air generated in the large array type heat exchanger unit is blown away through relay of the multiple jet fans, so that the phenomenon that the heat exchange effect is affected due to the cold island effect is avoided; the defrosting device has the advantages that cold air around the evaporator is rapidly removed, frost is avoided, the defrosting efficiency is high, and the working stability of the heat pump is high.

Description

Technical Field

[0001] The present invention relates to the technical field of heat pump exchangers, and particularly to a heat exchanger for a two-stage cascade heat pump. Background Art

[0002] A heat pump is an efficient energy conversion device that ingeniously utilizes the energy contained in the air to generate heat energy. The working principle of the heat pump is to efficiently collect and integrate the low-grade heat energy in the air through the internal circulation of the system, and then convert it into a high-temperature heat source. The generated heat energy not only has a higher temperature but also more stable quality, which can meet the needs of various heating and hot water supply. Compared with traditional heating and hot water supply methods, it can significantly reduce energy consumption and achieve energy-saving effects.

[0003] In the existing technology, there is a situation where a large amount of cold air is likely to accumulate during the use of the heat pump. Since the heat pump device absorbs heat from the surrounding during operation, the air temperature around the evaporator gradually decreases. As time goes by, the air circulation around the heat pump is severely affected, forming a relatively static low-temperature area, which further affects the normal operation of the heat pump device. Because of the poor air circulation, the heat pump is difficult to effectively absorb enough heat from the surrounding environment, resulting in a decrease in its heating efficiency. As the temperature continues to drop, the effect of the entire heat pump system will also be severely affected. It not only cannot meet the expected heating and hot water supply needs but may also increase energy consumption and operating costs.

[0004] Chinese Patent Document CN113776109A discloses an air source heat pump module and a tower-type air source heat pump. By changing the vertical placement of the heat pump to a horizontal placement and setting the air outlet to side air outlet, the air inlet and outlet are respectively carried out from both sides of the heat pump, avoiding the cold island effect and improving the air circulation to a certain extent. However, the heating efficiency of the heat pump device is closely related to its contact area with the air and the air circulation situation. The horizontal layout will lead to a reduction in the contact area between the heat pump device and the air, or make the air circulation not smooth enough, thus affecting its heating effect. Especially in low-temperature environments such as winter, this effect may be more obvious. Summary of the Invention

[0005] The purpose of the present invention is to provide a heat exchanger for a two-stage cascade heat pump to solve the problems such as the easy generation of a large amount of cold air accumulation and the influence on heating efficiency during the working process of common source pumps.

[0006] The present invention achieves the above object through the following technical solutions: It includes a chassis, which is composed of a support frame, a chassis bottom bracket, a protective plate, a top cover plate, a main control cabinet, and an evaporator. There is a top fan area above the evaporator, and a heat exchange unit below the evaporator. The heat exchange unit includes a low-temperature stage loop and a high-temperature stage loop. Ice removal mechanisms are provided on both sides of the bottom of the evaporator, air supply mechanisms are provided on both sides of the heat exchange unit, and jet fans are provided on the outside of the chassis; the jet fans generate a strong cylindrical high-speed air flow, and through the relay of multiple jet fans, a large amount of deposited cold air generated in the large array type heat exchanger unit is dispersed, avoiding the formation of a cold island effect and affecting the heat exchange effect.

[0007] Further, the ice removal mechanism includes two U-shaped mounting frames. Both sides of the two U-shaped mounting frames are respectively connected to the support frame and the evaporator by screws. Inside the U-shaped mounting frames, there is a fan module composed of several fans. One end of the fan module is provided with a C-shaped connecting piece, and one end of the fan module is provided with a transmission mounting plate. Both the C-shaped connecting piece and the transmission mounting plate are connected to the U-shaped mounting frames by screws. Both ends of the fan module are respectively connected to the C-shaped connecting piece and the transmission mounting plate through rotating shafts; the fan module pumps the hot air generated during the operation of the heat exchange unit to the evaporator, which can slightly increase the heat around the evaporator and thus improve the heat exchange efficiency.

[0008] Further, a servo motor is installed on the top of the transmission mounting plate. The output end of the servo motor is installed with a driving gear. A driven gear is installed on the outside of the rotating shaft at one end of the fan module and meshes with the driving gear. Dust covers are provided outside the driving gear and the driven gear, and the dust covers are connected to the transmission mounting plate by screws. The servo motor is electrically connected to the main control cabinet; the servo motor rotates the fan module through a gear set, adjusts the angle at which the fan module blows towards the evaporator, and directly blows the hot air generated by the heat exchange unit to the easily frozen part at the bottom of the fin condenser through the fan module, forming an ice melting effect and avoiding a large amount of ice hanging and affecting the heat exchange efficiency.

[0009] Further, the air supply mechanism includes a plate-shaped air supply box, which is connected to the support frame by screws. A transfer box body is installed on one side surface of one end of the air supply box, and a ventilation pipe is installed on the side surface of the transfer box body. The air supply box, the transfer box body, and the ventilation pipe are designed to be connected. A number of air guide plates are fixedly provided inside the air supply box. The air guide plates are arranged at equal intervals and are inclined in a horn shape. A number of ventilation openings are provided through one side wall of the air supply box. The ventilation openings are located between adjacent two air guide plates and are inclined in a horn shape. A vertical ventilation opening is provided through the outermost end of the side wall of the air supply box. The ventilation pipe passes through the protective plate and is connected to an external fan.

[0010] Furthermore, the top fan section includes a fan mounting bracket, which is connected to the top cover plate and the evaporator by screws. A number of large fans are installed inside the fan mounting bracket, and an infrared sensor is installed at the bottom of the fan mounting bracket. The infrared sensor is electrically connected to the main control cabinet. The infrared sensor monitors the parts of the fin condenser bottom that are prone to icing. After detecting that the freezing point is reached, it transmits an electrical signal to the main control, and the main control starts the servo motor to flip the fan module to heat and defrost the bottom of the fin condenser.

[0011] Furthermore, the evaporator includes a pair of fin condensers. One end of the fin condenser is provided with a refrigerant output pipe and a refrigerant input pipe, both of which are connected to the fin condenser in a penetrating manner. A heat conduction cavity is provided at the bottom of the fin condenser and is connected by screws. A temperature sensor is also installed on the evaporator. The refrigerant input pipe is composed of a main input pipe and several auxiliary input pipes connected in parallel. The auxiliary input pipes are connected to the fin condenser. The refrigerant output pipe forms a single output pipe with a thicker diameter after converging through a shunt pipe fitting.

[0012] Furthermore, a number of heat dissipation holes are provided on both sides of the heat conduction cavity. A heat conduction interface is installed at one end of the heat conduction cavity, and a heat energy transfer device is installed at the output end of the heat conduction interface. The connecting pipe at the output end of the heat energy transfer device penetrates through the air supply box. The heat energy transfer device is connected to the support frame. The heat dissipation holes are used to discharge the excess heat in the heat conduction cavity and dissipate it near the fin condenser. When the connecting pipe is connected to an external solar energy device, the heat energy provided by the solar energy device is converted through the heat energy transfer device and the medium and then sent into the heat conduction cavity to heat the fin condenser.

[0013] Further, the low-temperature stage loop includes three low-temperature stage compressors installed in parallel. There is a shock-absorbing device between the three low-temperature stage compressors and the machine bottom bracket, and they are connected by screws. On one side of the three low-temperature stage compressors, there is a low-temperature stage regenerative condenser. On the other side of the three low-temperature stage compressors, there is a low-temperature stage gas-liquid separator, which is connected by a pipeline. Both the low-temperature stage regenerative condenser and the low-temperature stage gas-liquid separator are connected to the machine bottom bracket by screws. On the side of the low-temperature stage gas-liquid separator, there is a four-way valve, which is connected to the machine bottom bracket by a bracket and screws. The four ports on the four-way valve are respectively connected to the low-temperature stage compressor, the refrigerant input pipe, the low-temperature stage regenerative condenser, and the low-temperature stage gas-liquid separator by pipelines; at least one or more of scroll compressors, rotary compressors, piston compressors, screw compressors, and centrifugal compressors are selected for the low-temperature stage compressor. One of a shell-and-tube heat exchanger and a double-pipe heat exchanger is selected for the low-temperature stage regenerative condenser. The interior of the heat exchanger of the low-temperature stage regenerative condenser does not have a liquid storage function but adopts a hollow design for filling heat storage materials. At least one or more of paraffin, composite salts, hydrated salts, and polyols are selected for the heat storage materials. The low-temperature stage gas-liquid separator, the low-temperature stage compressor, and the four-way valve are connected in series to form a small loop.

[0014] Further, the high-temperature stage loop includes a high-temperature stage compressor, which is connected to the machine bottom bracket by screws. On one side of the high-temperature stage compressor, there is a high-temperature stage condenser, which is connected by a pipeline. On the other side of the high-temperature stage compressor, there is an intermediate heat exchanger. Both the high-temperature stage condenser and the intermediate heat exchanger are connected to the machine bottom bracket by screws. There is a high-temperature stage throttle valve between the intermediate heat exchanger and the evaporator. The high-temperature stage throttle valve is connected to the support frame by a buckle and screws. There is a liquid accumulator on the side of the intermediate heat exchanger. The two ends of the high-temperature stage throttle valve are respectively connected to the refrigerant output pipe and the liquid accumulator by pipelines. There is a low-temperature stage throttle valve on the side of the liquid accumulator. One end of the low-temperature stage throttle valve is connected to the evaporator by a pipeline. The ports of the intermediate heat exchanger are respectively connected to the high-temperature stage compressor, the low-temperature stage throttle valve, the low-temperature stage regenerative condenser, and the liquid accumulator by pipelines; the high-temperature stage compressor has the same model as the low-temperature stage compressor. One of a shell-and-tube heat exchanger or a double-pipe heat exchanger is selected for the high-temperature stage condenser. At least one or more of a thermal expansion valve, an electronic expansion valve, and a capillary tube are selected for the low-temperature stage throttle valve and the high-temperature stage throttle valve.

[0015] Further, the shock absorption device includes a connection kit, which is connected to the low-temperature stage compressor by buckles and screws. There are two mounting plates below the connection kit. A number of rubber shock pads are provided between the mounting plates and the connection kit. The connection kit, the rubber shock pads, and the mounting plates are firmly connected by screws. A number of the rubber shock pads are also provided below the mounting plates. The mounting plates, the rubber shock pads, and the machine bottom bracket are firmly connected by screws. The three low-temperature stage compressors are connected to the mounting plates. When starting one or two of the low-temperature stage compressors to work, the vibration is transmitted to the mounting plates, causing the three low-temperature stage compressors to vibrate regularly together with the connection kit, the rubber shock pads, and the connection screws, avoiding the loosening of the connection caused by the vibration of the screws while some of the low-temperature stage compressors do not vibrate.

[0016] Beneficial effects: The present invention is reasonably designed, simple and stable in structure, and has strong practicability, and has the following beneficial effects:

[0017] 1. In the solution of the present invention, the cascade heat pump cycle system adopts a coupling design of a low-temperature stage circuit and a high-temperature stage circuit. The low-temperature stage circuit absorbs low-temperature heat from the evaporator through three parallel compressors. After being switched by the four-way valve, the low-temperature stage regenerative condenser stores and releases heat by filling phase change materials such as paraffin / composite salt. The high-temperature stage circuit receives the heat of the low-temperature stage through the intermediate heat exchanger. After being heated up again by the high-temperature stage compressor, it outputs high-grade heat energy through the high-temperature stage condenser. The refrigerant flow rates of the two circuits are synergistically adjusted by the throttle valve to achieve efficient operation in a wide temperature range;

[0018] 2. In the solution of the present invention, a low-temperature stage regenerative condenser is added to the low-temperature stage circuit of the cascade heat pump system. The low-temperature stage regenerative condenser is not only connected to the intermediate heat exchanger through the refrigerant, but also connected to the high-temperature stage condenser through the heating medium, forming a cross-cascade heat pump system. The accuracy requirement for the coupling time of the high-temperature stage circuit and the low-temperature stage circuit through the intermediate heat exchanger is greatly reduced, and the stability of the operation of the cascade heat pump system is improved;

[0019] 3. In the solution of the present invention, heat storage materials are filled in the low-temperature stage regenerative condenser. In the case of a sudden power outage during the operation of the heat pump, the heat storage materials can provide heat for the low-temperature stage regenerative condenser and at the same time provide heat for the high-temperature condenser, preventing the water in the high-temperature condenser from freezing and expanding, causing fatal damage to the heat pump, and greatly improving the anti-freezing ability;

[0020] 4. In the solution of the present invention, a rotatable fan module is provided at the bottom of the evaporator, and the 0-80° angle adjustment is realized by driving a gear set through a servo motor. When the infrared sensor detects that the temperature at the bottom of the fin condenser reaches the freezing point, the main control system starts the fan module to turn towards the icing area, and blows the waste hot air generated during the operation of the heat exchange unit in a directional manner. Combined with the heat conduction cavity and solar-assisted heating, rapid defrosting is achieved. The defrosting process cooperates with the cylindrical high-speed air flow formed by the jet fan to eliminate the "cold island effect" caused by the deposition of cold air;

[0021] 5. In the solution of the present invention, a three-stage air supply structure is adopted. The air guide plates on both sides of the heat exchange unit and the horn-shaped ventilation openings form laminar air supply, which promotes the air circulation in the heat exchange unit and avoids heat accumulation; the fan module that can be flipped in the middle forms air delivery from low to high, which promotes the flow of hot air towards the evaporator; the large fan at the top constructs negative pressure drainage. The jet fan array penetrates the gaps between the heat exchanger arrays through relay high-speed air flow, reduces the boundary layer thermal resistance, and the wind field system is linked with the temperature sensor to dynamically adjust the wind speed and angle according to the heat load, improving the overall heat exchange capacity;

[0022] 6. In the solution of the present invention, three low-temperature compressors form an overall shock absorption system through a connecting kit and rubber shock pads. Using the mass-spring effect, the vibration frequency is unified to the same amplitude range to avoid local resonance. The regenerative condenser stores excess heat at low loads and realizes heat time shift through a four-way valve switch during peak hours. The system monitors the operating parameters in real time through the main control cabinet, and uses algorithms to optimize the start-stop combination of the compressors and the wind field configuration to improve the comprehensive energy efficiency ratio to a relatively high level;

[0023] 7. In the solution of the present invention, when a large amount of cold air accumulates and freezes and frosts in the evaporator, the heat pump enters the defrosting mode. The refrigerant flow direction is from the intermediate heat exchanger to the low-temperature regenerative condenser, and the heat conducted to the refrigerant through the high-temperature circuit melts the frost outside the low-temperature circuit, avoiding the frost from affecting the normal use of the heat pump equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic structural diagram of the present invention;

[0025] Figure 2 It is a schematic partial structural diagram of the present invention;

[0026] Figure 3 It is a schematic structural diagram of the evaporator of the present invention;

[0027] Figure 4 It is a schematic partial A structural diagram of the present invention;

[0028] Figure 5 It is a schematic partial structural diagram of the evaporator of the present invention;

[0029] Figure 6Schematic diagram of the top fan area structure of the present invention;

[0030] Figure 7 Schematic diagram of the ice removal mechanism structure of the present invention;

[0031] Figure 8 Exploded view of the air supply mechanism structure of the present invention;

[0032] Figure 9 Schematic diagram of the heat exchange unit structure of the present invention;

[0033] Figure 10 Schematic diagram of the shock absorption device structure of the present invention.

[0034] In the figure: 1 - chassis, 2 - evaporator, 3 - top fan area, 4 - heat exchange unit, 5 - ice removal mechanism, 6 - air supply mechanism, 7 - jet fan;

[0035] 21 - fin condenser, 22 - refrigerant output pipe, 23 - refrigerant input pipe, 24 - heat conduction cavity, 25 - temperature sensor, 31 - fan mounting bracket, 32 - large fan, 33 - infrared sensor, 41 - low - temperature stage loop, 42 - high - temperature stage loop, 51 - loop - shaped mounting bracket, 52 - fan module, 53 - C - type connecting piece, 54 - drive mounting plate, 55 - servo motor, 56 - driving gear, 57 - driven gear, 61 - air supply box, 62 - transfer box body, 63 - ventilation pipe, 64 - air deflector, 65 - ventilation opening, 66 - vertical ventilation opening;

[0036] 241 - heat exhaust port, 242 - heat conduction interface, 243 - heat energy transfer device, 411 - low - temperature stage compressor, 412 - shock absorption device, 413 - low - temperature stage regenerative condenser, 414 - low - temperature stage gas - liquid separator, 415 - four - way valve, 416 - low - temperature stage throttle valve, 421 - high - temperature stage compressor, 422 - high - temperature stage condenser, 423 - intermediate heat exchanger, 424 - high - temperature stage throttle valve, 425 - liquid storage tank;

[0037] 4121 - connection kit, 4122 - mounting plate, 4123 - rubber shock pad. Detailed implementation manners

[0038] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0039] Combined with Figure 1 And Figure 10As shown in the figure, a heat exchanger for a two-stage cascade heat pump includes a chassis 1, which is composed of a support frame, a bottom bracket, a protective plate, a top cover plate, a main control cabinet, and an evaporator 2. Above the evaporator 2, there is a top fan area 3. Below the evaporator 2, there is a heat exchange unit 4, which includes a low-temperature stage circuit 41 and a high-temperature stage circuit 42. On both sides of the bottom of the evaporator 2, there is an ice-removing mechanism 5. On both sides of the heat exchange unit 4, there is a air supply mechanism 6. On the outside of the chassis 1, there is a jet fan 7. The jet fan 7 generates a strong cylindrical high-speed air flow, and through the relay of multiple jet fans 7, a large amount of deposited cold air generated in the large array heat exchanger unit is dispersed, avoiding the formation of a cold island effect and affecting the heat exchange effect.

[0040] Combined with Figure 3 and Figure 7 As shown in the figure, the ice-removing mechanism 5 includes two U-shaped mounting brackets 51. On both sides of the two U-shaped mounting brackets 51, they are respectively connected to the support frame and the evaporator 2 by screws. Inside the U-shaped mounting brackets 51, there is a fan module 52 composed of several fans. At one end of the fan module 52, there is a C-shaped connecting piece 53. At one end of the fan module 52, there is a transmission mounting plate 54. Both the C-shaped connecting piece 53 and the transmission mounting plate 54 are connected to the U-shaped mounting brackets 51 by screws. Both ends of the fan module 52 are respectively connected to the C-shaped connecting piece 53 and the transmission mounting plate 54 through rotating shafts. The fan module 52 sucks the hot air generated during the operation of the heat exchange unit 4 to the evaporator 2, which can slightly increase the heat around the evaporator 2 and thus increase the heat exchange efficiency.

[0041] Combined with Figure 7 As shown in the figure, a servo motor 55 is installed on the top of the transmission mounting plate 54. The output end of the servo motor 55 is installed with a driving gear 56. On the outside of the rotating shaft at one end of the fan module 52, there is a driven gear 57 which meshes with the driving gear 56 for transmission. A dust-proof cover is arranged outside the driving gear 56 and the driven gear 57, and the dust-proof cover is connected to the transmission mounting plate 54 by screws. The servo motor 55 is electrically connected to the main control cabinet. The servo motor 55 rotates the fan module 52 through a gear set, adjusts the angle at which the fan module 52 blows towards the evaporator 2, and directly blows the hot air generated by the heat exchange unit 4 to the easily frozen part at the bottom of the fin condenser 21 through the fan module 52 to form an ice-melting effect and avoid a large amount of ice hanging and affecting the heat exchange efficiency.

[0042] Combined with Figure 8As shown in the figure, the air supply mechanism 6 includes a plate-shaped air supply box 61. The air supply box 61 is connected to the support frame by screws. A transfer box body 62 is installed on one side of the air supply box 61. A ventilation pipe 63 is installed on the side of the transfer box body 62. The air supply box 61, the transfer box body 62 and the ventilation pipe 63 are designed to be connected. A number of air guide plates 64 are fixedly arranged inside the air supply box 61. The air guide plates 64 are arranged at equal intervals and are inclined in a horn shape. A number of ventilation openings 65 are penetrated through one side wall of the air supply box 61. The ventilation openings 65 are located between adjacent two air guide plates 64 and are inclined in a horn shape. A vertical ventilation opening 66 is penetrated through the outermost end of the side wall of the air supply box 61. The ventilation pipe 63 is connected to an external fan after penetrating through the protection plate.

[0043] Combined with Figure 1 and Figure 6 As shown in the figure, the top fan sector 3 includes a fan mounting frame 31. The fan mounting frame 31 is connected to the top cover plate and the evaporator 2 by screws. A number of large fans 32 are installed inside the fan mounting frame 31. An infrared sensor 33 is installed at the bottom of the fan mounting frame 31. The infrared sensor 33 is electrically connected to the main control cabinet; the infrared sensor 33 monitors the parts of the bottom of the fin condenser 21 that are prone to icing. After detecting that the freezing point is reached, an electrical signal is transmitted to the main control. The main control starts the servo motor 55 to flip the fan module 52 to heat and de-ice the bottom of the fin condenser 21.

[0044] Combined with Figures 2 to 5 As shown in the figure, the evaporator 2 includes a pair of fin condensers 21. A refrigerant output pipe 22 and a refrigerant input pipe 23 are provided at one end of the fin condenser 21. The refrigerant output pipe 22 and the refrigerant input pipe 23 are both connected to the fin condenser 21 through penetration. A heat conduction cavity 24 is provided at the bottom of the fin condenser 21 and is connected by screws. A temperature sensor 25 is also installed on the evaporator 2; the refrigerant input pipe is composed of a main input pipe and a number of auxiliary input pipes in parallel. The auxiliary input pipes are connected to the fin condenser 21. The refrigerant output pipe 22 forms a single output pipe with a thicker diameter after converging through a shunt pipe fitting.

[0045] Combined with Figure 3 and Figure 5 As shown in the figure, a number of heat dissipation holes 241 are provided on both sides of the heat conduction cavity 24. A heat conduction interface 242 is installed at one end of the heat conduction cavity 24. A heat energy transfer device 243 is installed at the output end of the heat conduction interface 242. The connecting pipe at the output end of the heat energy transfer device 243 penetrates through the air supply box 61; the heat energy transfer device 243 is connected to the support frame. The heat dissipation holes 241 are used to discharge the excess heat in the heat conduction cavity 24 and dissipate it near the fin condenser 21. When the connecting pipe is connected to an external solar energy device, the heat energy provided by the solar energy device is converted through the heat energy transfer device 243 and the medium and then sent into the heat conduction cavity 24 to heat the fin condenser 21.

[0046] Combined withFigure 9 As shown, the low-temperature stage loop 41 includes three low-temperature stage compressors 411 installed in parallel. A shock-absorbing device 412 is provided between the three low-temperature stage compressors 411 and the bottom bracket of the machine, and they are connected by screws. On one side of the three low-temperature stage compressors 411, there is a low-temperature stage regenerative condenser 413. On the other side of the three low-temperature stage compressors 411, there is a low-temperature stage gas-liquid separator 414, which is connected by a pipeline. Both the low-temperature stage regenerative condenser 413 and the low-temperature stage gas-liquid separator 414 are connected to the bottom bracket of the machine by screws. A four-way valve 415 is provided on the side of the low-temperature stage gas-liquid separator 414. The four-way valve 415 is connected to the bottom bracket of the machine by a bracket and screws. The four ports on the four-way valve 415 are respectively connected to the low-temperature stage compressor 411, the refrigerant input pipe 23, the low-temperature stage regenerative condenser 413, and the low-temperature stage gas-liquid separator 414 by pipelines. The low-temperature stage compressor 411 selects at least one or a combination of scroll compressors, rotor compressors, piston compressors, screw compressors, and centrifugal compressors. The low-temperature stage regenerative condenser 413 selects one of a shell-and-tube heat exchanger and a double-pipe heat exchanger. The interior of the heat exchanger of the low-temperature stage regenerative condenser 413 does not have a liquid storage function but adopts a hollow design for filling heat storage materials. The heat storage materials select at least one or a combination of paraffin, composite salts, hydrated salts, and polyols. The low-temperature stage gas-liquid separator 414, the low-temperature stage compressor 411, and the four-way valve 415 are connected in series to form a small loop.

[0047] Combined with Figure 9 As shown, the high-temperature stage loop 42 includes a high-temperature stage compressor 421. The high-temperature stage compressor 421 is connected to the bottom bracket of the machine by screws. On one side of the high-temperature stage compressor 421, there is a high-temperature stage condenser 422, which is connected by a pipeline. On the other side of the high-temperature stage compressor 421, there is an intermediate heat exchanger 423. Both the high-temperature stage condenser 422 and the intermediate heat exchanger 423 are connected to the bottom bracket of the machine by screws. A high-temperature stage throttle valve 424 is provided between the intermediate heat exchanger 423 and the evaporator 2. The high-temperature stage throttle valve 424 is connected to the support frame by a buckle and screws. A liquid reservoir 425 is provided on the side of the intermediate heat exchanger 423. The two ends of the high-temperature stage throttle valve 424 are respectively connected to the refrigerant output pipe 22 and the liquid reservoir 425 by pipelines. A low-temperature stage throttle valve 416 is provided on the side of the liquid reservoir 425. One end of the low-temperature stage throttle valve 416 is connected to the evaporator 2 by a pipeline. The ports of the intermediate heat exchanger 423 are respectively connected to the high-temperature stage compressor 421, the low-temperature stage throttle valve 416, the low-temperature stage regenerative condenser 413, and the liquid reservoir 425 by pipelines. The high-temperature stage compressor 421 has the same model as the low-temperature stage compressor 411. The high-temperature stage condenser 422 selects a shell-and-tube heat exchanger or a double-pipe heat exchanger. The low-temperature stage throttle valve 416 and the high-temperature stage throttle valve 424 select at least one or a combination of a thermal expansion valve, an electronic expansion valve, and a capillary tube.

[0048] Combined with Figure 10As shown in the figure, the shock absorption device 412 includes a connection kit 4121. The connection kit 4121 is connected to the low-temperature stage compressor 411 by a buckle and screws. There are two mounting plates 4122 below the connection kit 4121. There are several rubber shock pads 4123 between the mounting plates 4122 and the connection kit 4121. The connection kit 4121, the rubber shock pads 4123, and the mounting plates 4122 are firmly connected by screws. There are also several rubber shock pads 4123 below the mounting plates 4122. The mounting plates 4122, the rubber shock pads 4123, and the machine bottom bracket are firmly connected by screws; Three low-temperature stage compressors 411 are connected to the mounting plates 4122. When one or two of the low-temperature stage compressors 411 are started to work, the vibration is transmitted to the mounting plates, causing the three low-temperature stage compressors 411, the connection kit 4121, the rubber shock pads 4123, and the connecting screws to vibrate regularly, avoiding the loosening of the connection caused by the vibration of some of the low-temperature stage compressors 411 not vibrating while the screws vibrate.

[0049] Working principle: During the use of the present invention, in the normal heating mode, the refrigerant flow direction is from the low-temperature stage regenerative condenser 413 to the intermediate heat exchanger 423. When a large amount of cold air accumulates and freezes and frosts on the evaporator 2, the heat pump enters the defrosting mode, and the refrigerant flow direction is from the intermediate heat exchanger 423 to the low-temperature stage regenerative condenser 413. The heat conducted to the refrigerant through the high-temperature stage circuit 42 melts the frost outside the low-temperature stage circuit 41, enhancing the defrosting efficiency of the cross-overlapping heat pump system;

[0050] The rotatable fan module 52 at the bottom of the evaporator 2 realizes 0-80° angle adjustment by driving the gear set with a servo motor 55. When the infrared sensor 33 detects that the temperature at the bottom of the fin condenser 21 reaches the freezing point, the main control system starts the fan module 52 to turn to the icing area, directing the waste hot air generated during the operation of the heat exchange unit 4, and combining with the solar energy-assisted heating through the heat conduction cavity 24 to achieve rapid de-icing;

[0051] The jet fans 7 on the sides of multiple groups of heat exchangers form a relay-type combined air duct. Under the synergistic action of the cylindrical high-speed air flow, a large amount of deposited cold air generated in the large-scale array heat exchanger unit is eliminated, avoiding the "cold island effect" caused by the deposition of cold air.

[0052] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, in any aspect, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention. Any reference signs in the claims should not be construed as limiting the claims involved.

[0053] In addition, it should be understood that although this specification is described in terms of embodiments, not every embodiment only contains an independent technical solution. This narrative style of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A heat exchanger for a two-stage cascade heat pump, comprising a chassis (1), the chassis (1) consisting of a support frame, a chassis bottom bracket, a protective plate, a top cover plate, a main control cabinet, and an evaporator (2), characterized in that: Above the evaporator (2), there is a top fan section (3). Below the evaporator (2), there is a heat exchange unit (4). The heat exchange unit (4) includes a low-temperature stage circuit (41) and a high-temperature stage circuit (42). On both sides of the bottom of the evaporator (2), there are ice removal mechanisms (5). On both sides of the heat exchange unit (4), there are air supply mechanisms (6). Outside the chassis (1), there is a jet fan (7).

2. The heat exchanger for a two-stage cascade heat pump according to claim 1, wherein: The ice removal mechanism (5) includes two U-shaped mounting frames (51). On both sides of the two U-shaped mounting frames (51), they are respectively connected to the support frame and the evaporator (2) by screws. Inside the U-shaped mounting frame (51), there is a fan module (52) composed of several fans. At one end of the fan module (52), there is a C-shaped connecting piece (53). At one end of the fan module (52), there is a transmission mounting plate (54). Both the C-shaped connecting piece (53) and the transmission mounting plate (54) are connected to the U-shaped mounting frame (51) by screws. Both ends of the fan module (52) are connected to the C-shaped connecting piece (53) and the transmission mounting plate (54) through rotating shafts respectively.

3. A heat exchanger for a two-stage cascade heat pump according to claim 2, characterized in that: On the top of the transmission mounting plate (54), a servo motor (55) is installed. On the output end of the servo motor (55), a driving gear (56) is installed. On the outside of the rotating shaft at one end of the fan module (52), a driven gear (57) is installed and meshes with the driving gear (56) for transmission. Outside the driving gear (56) and the driven gear (57), there is a dust-proof cover. The dust-proof cover is connected to the transmission mounting plate (54) by screws. The servo motor (55) is electrically connected to the main control cabinet.

4. A heat exchanger for a two-stage cascade heat pump according to claim 3, characterized in that: The air supply mechanism (6) includes a plate-shaped air supply box (61). The air supply box (61) is connected to the support frame by screws. On one side surface of one end of the air supply box (61), a transfer box body (62) is installed. On the side surface of the transfer box body (62), a ventilation pipe (63) is installed. The air supply box (61), the transfer box body (62), and the ventilation pipe (63) are designed to be connected. Inside the air supply box (61), several air guide plates (64) are fixedly installed. The air guide plates (64) are arranged at equal intervals and are inclined in a horn shape. On one side wall of the air supply box (61), several ventilation openings (65) are penetrated. The ventilation openings (65) are located between adjacent two air guide plates (64) and are inclined in a horn shape. At the outermost end of the side wall of the air supply box (61), a vertical ventilation opening (66) is penetrated. The ventilation pipe (63) is connected to an external fan after penetrating the protection plate.

5. A heat exchanger for a two-stage cascade heat pump according to claim 4, characterized in that: The top fan section (3) includes a fan mounting frame (31). The fan mounting frame (31) is connected to the top cover plate and the evaporator (2) by screws. Inside the fan mounting frame (31), several large fans (32) are installed. At the bottom of the fan mounting frame (31), an infrared sensor (33) is installed. The infrared sensor (33) is electrically connected to the main control cabinet.

6. The heat exchanger for a two-stage cascade heat pump according to claim 5, characterized in that: The evaporator (2) includes a pair of finned condensers (21). One end of the finned condenser (21) is provided with a refrigerant output pipe (22) and a refrigerant input pipe (23). The refrigerant output pipe (22) and the refrigerant input pipe (23) are both connected to the finned condenser (21) in a penetrating manner. A heat conduction cavity (24) is provided at the bottom of the finned condenser (21) and is connected by screws. A temperature sensor (25) is also installed on the evaporator (2).

7. The heat exchanger for a two-stage cascade heat pump according to claim 6, characterized in that: A number of heat dissipation holes (241) are provided on both sides of the heat conduction cavity (24). A heat conduction interface (242) is installed at one end of the heat conduction cavity (24). A heat energy transfer device (243) is installed at the output end of the heat conduction interface (242). The connecting pipe at the output end of the heat energy transfer device (243) penetrates through the air supply box (61).

8. A heat exchanger for a two-stage cascade heat pump according to claim 7, characterized in that: The low-temperature stage loop (41) includes three low-temperature stage compressors (411) installed in parallel. A shock absorption device (412) is provided between the three low-temperature stage compressors (411) and the machine bottom bracket and is connected by screws. A low-temperature stage regenerative condenser (413) is provided on one side of the three low-temperature stage compressors (411). A low-temperature stage gas-liquid separator (414) is provided on the other side of the three low-temperature stage compressors (411) and is connected by a pipeline. The low-temperature stage regenerative condenser (413) and the low-temperature stage gas-liquid separator (414) are both connected to the machine bottom bracket by screws. A four-way valve (415) is provided on the side of the low-temperature stage gas-liquid separator (414). The four-way valve (415) is connected to the machine bottom bracket by a bracket and screws. The four ports on the four-way valve (415) are respectively connected to the low-temperature stage compressor (411), the refrigerant input pipe (23), the low-temperature stage regenerative condenser (413), and the low-temperature stage gas-liquid separator (414) by pipelines.

9. A heat exchanger for a two-stage cascade heat pump according to claim 8, characterized in that: The high-temperature stage loop (42) includes a high-temperature stage compressor (421). The high-temperature stage compressor (421) is connected to the bottom bracket by screws. A high-temperature stage condenser (422) is provided on one side of the high-temperature stage compressor (421) and is connected by a pipeline. An intermediate heat exchanger (423) is provided on the other side of the high-temperature stage compressor (421). The high-temperature stage condenser (422) and the intermediate heat exchanger (423) are both connected to the bottom bracket by screws. A high-temperature stage throttle valve (424) is provided between the intermediate heat exchanger (423) and the evaporator (2). The high-temperature stage throttle valve (424) is connected to the support frame by a buckle and screws. A liquid accumulator (425) is provided on the side of the intermediate heat exchanger (423). Both ends of the high-temperature stage throttle valve (424) are connected to the refrigerant output pipe (22) and the liquid accumulator (425) by pipelines. A low-temperature stage throttle valve (416) is provided on the side of the liquid accumulator (425). One end of the low-temperature stage throttle valve (416) is connected to the evaporator (2) by a pipeline. The ports of the intermediate heat exchanger (423) are connected to the high-temperature stage compressor (421), the low-temperature stage throttle valve (416), the low-temperature regenerative condenser (413), and the liquid accumulator (425) by pipelines.

10. A heat exchanger for a two-stage cascade heat pump according to claim 9, characterized in that: The shock absorption device (412) includes a connection kit (4121). The connection kit (4121) is connected to the low-temperature stage compressor (411) by a buckle and screws. Two mounting plates (4122) are provided below the connection kit (4121). A number of rubber shock pads (4123) are provided between the mounting plates (4122) and the connection kit (4121). The connection kit (4121), the rubber shock pads (4123), and the mounting plates (4122) are tightly connected by screws. A number of the rubber shock pads (4123) are also provided below the mounting plates (4122). The mounting plates (4122), the rubber shock pads (4123), and the bottom bracket are tightly connected by screws.

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