Rankine circulation system, Rankine refrigeration cycle and refrigerated vehicle

Abstract

The present invention provides a Rankine circulation system (1), a Rankine refrigeration cycle (2), and a refrigerated vehicle that can operate effectively even when there is no waste heat source. The Rankine circulation system (1) includes a first evaporator (11), an expander (12), a condenser (13), and a refrigerant pump (14) that are connected in series and in a circulating manner, and the Rankine circulation system (1) further includes an electric heating device (15) that is connected between the refrigerant pump (14) and the expander (12) and heats the refrigerant. In the present invention, when there is no waste heat source in the Rankine circulation system (1), energy can be continuously supplied to the Rankine circulation via the electric heating device (15), so that the expander (12) can output mechanical work continuously and effectively, and even when there is no waste heat source, the Rankine circulation can be operated normally and can be adapted to more operating conditions.

Description

[Technical field]

[0001] The present invention relates to a Rankine circulation system, a Rankine refrigeration cycle, and a refrigerated vehicle, and more particularly to a Rankine circulation system, a Rankine refrigeration cycle, and a refrigerated vehicle that are adaptable to a wider range of operating conditions. [Background technology]

[0002] Conventional Rankine circulation systems, Rankine refrigeration cycles, and refrigerated vehicles use an organic Rankine circulation system to convert waste heat energy into mechanical work, and transmit the mechanical work output from an expander of the organic Rankine circulation system to a compressor of a refrigeration cycle through a transmission mechanism to realize the operation of a heat-driven refrigeration cycle, or transmit the mechanical work output from the expander to another device for other use.

[0003] However, when the refrigerated truck is not running, no waste heat is generated, which causes the refrigerant to not evaporate sufficiently, which in turn causes the expander to not operate normally and stably, and the compressor to not operate normally and stably, ultimately causing the refrigeration cycle to not be able to cool effectively. Summary of the Invention

[0004] An object of the present invention is to provide a Rankine circulation system, a Rankine refrigeration cycle and a refrigerated vehicle that are adaptable to a wider range of operating conditions.

[0005] In order to achieve the above object of the invention, the present invention adopts the following technical solution: a Rankine circulation system, comprising a first evaporator, an expander, a condenser and a refrigerant pump, which are connected in a sequential manner, and the Rankine circulation system further comprises at least two heating methods for supplying heat to the first evaporator.

[0006] Furthermore, the heating method is waste heat heating, electric heating, combustion heating, geothermal heating or residual heat heating.

[0007] Furthermore, the Rankine circulation system further includes a heating device connected between the refrigerant pump and the expander and configured to heat the refrigerant, The heating device is an electromagnetic induction heating device, and the electromagnetic induction heating device includes an electromagnetic heating controller and an electromagnetic induction coil connected to the electromagnetic heating controller, and the electromagnetic induction coil is provided outside a pipe between the first evaporator and the expander. Alternatively, the heating device is a combustion heating device or a heat radiation device.

[0008] Furthermore, the Rankine circulation system further includes a detection device provided between the heating device and the expander, which detects a temperature and / or a pressure of the refrigerant.

[0009] Furthermore, the refrigerant pump is an inverter-controlled refrigerant pump.

[0010] The present invention also relates to a Rankine refrigeration cycle, comprising a refrigeration cycle in which a compressor, a first heat exchanger, a throttling mechanism, and a second evaporator are connected in sequence in a circulating manner, and the Rankine circulation system according to claim 1, and further comprising a transmission mechanism connecting the expander and the compressor.

[0011] Further, the first heat exchanger includes a first fluid passage and a second fluid passage, the first fluid passage being connected between the compressor and the throttling mechanism, and the second fluid passage being connected between the refrigerant pump and the first evaporator, The compressor further includes a second heat exchanger, the second heat exchanger including a first fluid passage and a second fluid passage, the first fluid passage being connected between the second evaporator and the compressor, and the second fluid passage being connected between the expander and the condenser.

[0012] Furthermore, the compressor has a first operating state in which it is connected to the expander via the transmission mechanism, and a second operating state in which it is connected to an electric power drive mechanism.

[0013] Furthermore, the transmission mechanism includes a main drive shaft connected to the expander and an auxiliary drive shaft connected to the compressor, and the main drive shaft and the auxiliary drive shaft are detachably connected to each other, The electric power drive mechanism includes a first clutch attached to the auxiliary drive shaft, a drive motor cooperating with the first clutch, and a connection structure connecting the first clutch and the drive motor.

[0014] Furthermore, the transmission mechanism further includes a connection device for connecting the main drive shaft and the auxiliary drive shaft, the connection device including a coupling fixed to one of the main drive shaft and the auxiliary drive shaft, and a second clutch cooperating with the other of the main drive shaft and fixed to the coupling. Alternatively, the transmission mechanism further includes a connection device for connecting the main drive shaft and the auxiliary drive shaft, the connection device including a coupling fixed to one of the main drive shaft and the auxiliary drive shaft, and a second clutch cooperating with the other of the main drive shaft and fixed to the coupling, the connection device including a first gear attached to the main drive shaft and a second gear attached to the auxiliary drive shaft and cooperating with the first gear, the first gear and the second gear having different diameters. Alternatively, the transmission mechanism further includes a connection device for connecting the main drive shaft and the auxiliary drive shaft, the connection device including a coupling fixed to one of the main drive shaft and the auxiliary drive shaft, and a second clutch cooperating with the other of the main drive shaft and fixed to the coupling, the connection device including a first gear attached to the main drive shaft, a second clutch fixed to the first gear, and a second gear attached to the auxiliary drive shaft and cooperating with the first gear, the first gear and the second gear have different diameters, and the first gear rotates and drives the main drive shaft via the second clutch.

[0015] Furthermore, the first clutch is an energized on-coming clutch, and the second clutch is an energized on-coming clutch.

[0016] Furthermore, the electric power drive mechanism further includes a power supply module that supplies electric power to the first clutch, the second clutch, and the drive motor.

[0017] The cooling system further includes a subcooling degree controller connected between the first heat exchanger and the throttling mechanism.

[0018] The present invention also provides a refrigerated car having a refrigerated box, The Rankine cycle refrigeration system further comprises a first evaporator of the Rankine cycle refrigeration system thermally connected to the waste heat source of the refrigerated vehicle through a heat conduction structure, and the evaporator of the refrigeration cycle supplies cold to the refrigerated box through a cooling unit.

[0019] The present invention further includes an engine and a cooling mechanism for cooling the engine, the heat transfer mechanism connecting the cooling mechanism and the first evaporator. Alternatively, the refrigerator may further include a cold storage device for supplying cold heat to the refrigerated box, and the second evaporator is thermally conductively connected to the cold storage device.

[0020] By providing an electric heating device between the refrigerant pump and the expander, the Rankine cycle system of the present invention can continue to supply energy to the Rankine cycle via the electric heating device even when there is no waste heat source, allowing the expander to output mechanical work continuously and effectively. Furthermore, even when there is no waste heat source, the Rankine cycle can operate normally, making it possible to adapt to a wider range of operating conditions. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is a schematic diagram of a Rankine refrigeration cycle of the present invention. [Diagram 2] 1 is a perspective view of a first embodiment of an expander and a compressor of the present invention; [Diagram 3] FIG. 2 is an exploded perspective view of FIG. [Figure 4] FIG. 2 is a perspective view of a second embodiment of the expander and compressor of the present invention. [Diagram 5] FIG. 5 is an exploded perspective view of FIG. [Figure 6] FIG. 11 is a perspective view of a third embodiment of the expander and compressor of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] The present invention will be described in detail below with reference to the embodiments shown in the drawings, however, the present invention is not limited to these embodiments, and any structural, method or functional modifications made by those skilled in the art based on these embodiments are within the scope of protection of the present invention.

[0023] 1 to 6, in the Rankine circulation system 1 of the present invention, a first evaporator 11, an expander 12, a condenser 13, and a refrigerant pump 14 are connected in sequence in a circulating manner. The Rankine circulation system 1 further includes a heating device 15 connected between the refrigerant pump 14 and the expander 12 to heat the refrigerant. This allows the Rankine circulation to operate stably even in an initial operation stage, allows mechanical work to be output effectively, and at the same time, prevents liquid refrigerant from entering the expander 12.

[0024] In this embodiment, as shown in FIG. 1, the Rankine cycle system 1 is an organic Rankine cycle system, which is mainly used to convert waste heat energy (waste heat) into mechanical work. The expander 12 can be connected to other devices such as a generator and a compressor 21 through a transmission device, so that the mechanical work of the expander 12 can be converted into a power source for other devices, and electrical energy or other forms of energy can be obtained to meet corresponding needs.

[0025] Specifically, as shown in Figures 1 to 5, the refrigerant pump 14 and the first evaporator 11 are connected to form a circulation, and the first evaporator 11 absorbs waste heat energy to evaporate the refrigerant, which then enters the expander 12 to perform work, and the refrigerant flows from the expander 12 to the condenser 13 to release heat, and the refrigerant is further pressurized and driven by the refrigerant pump 14 to enter the first evaporator 11, thereby forming a complete circulation.

[0026] In this embodiment, the heating device 15 is an electromagnetic induction heating device, so that the heating device 15 is easy to obtain and easy to install. Specifically, the electromagnetic induction heating device includes an electromagnetic heating controller and an electromagnetic induction coil connected to the electromagnetic heating controller. The electromagnetic induction coil is disposed outside the piping between the first evaporator 11 and the expander 12. Of course, the electric heating method is not limited to the electromagnetic induction heating device.

[0027] When an electromagnetic induction heating device is in operation, the alternating current generated after electricity is passed through an electromagnetic induction coil, generating an alternating magnetic field, and a pipe is placed inside it to cut the alternating magnetic field lines, thereby generating alternating currents (i.e., eddy currents) inside the object. The eddy currents cause the atoms inside the object to move at high speed and irregularly, causing collisions and friction between the atoms, generating thermal energy and resulting in a heating effect.

[0028] The present invention further provides another heating device 15. For example, the heating device 15 may be a combustion heating device or a heat radiation device. The combustion heating device is a device that generates heat by burning other combustible substances such as fossil fuels and biofuels. The heat radiation device is a device that transfers heat from a high temperature side to a refrigerant by a thermal conduction method to perform heat exchange and heat the refrigerant, and heats the refrigerant by heat exchange between the refrigerant and other heat sources such as waste heat, residual heat, biomass heat, and hot spring heat.

[0029] Of course, in other embodiments, the heating device 15 may be another device as long as it can heat the refrigerant in the pipe between the first evaporator 11 and the expander 12.

[0030] Furthermore, the Rankine circulation system 1 has at least two types of heating methods for supplying heat to the first evaporator 11. Specifically, the heating methods may be other heating methods such as waste heat heating, electric heating, combustion heating, geothermal heating, or residual heat heating, and are not limited to the above heating methods as long as they can supply heat to the first evaporator 11.

[0031] The Rankine circulation system 1 further includes a detection device 16 disposed between the heating device 15 and the expander 12 and detecting the temperature and / or pressure of the refrigerant. The detection device 16 can detect whether the refrigerant has sufficiently evaporated. In this embodiment, the detection device 16 is a temperature sensor disposed between the first evaporator 11 and the expander 12 and detects the temperature at the outlet of the first evaporator 11 or the inlet of the expander 12, and determines whether the refrigerant has sufficiently evaporated by detecting the temperature when the refrigerant leaves the first evaporator 11 or before entering the expander 12. This makes it possible to timely and effectively determine whether heating is necessary and the heating time based on the state of the refrigerant, reducing the risk that the expander 12 will not be able to operate normally due to insufficiently evaporated refrigerant entering the expander 12, and further ensuring stable operation of the expander 12.

[0032] In this embodiment, the piping of the Rankine circulation system 1 is generally made of copper, and since copper has good thermal conductivity, the temperature of the copper surface can represent the temperature of the refrigerant. Therefore, the temperature sensor only needs to measure the temperature of the piping surface, and therefore the installation of the temperature sensor is very simple, and it is only necessary to install the temperature sensor on the piping and measure the piping surface temperature.

[0033] Of course, in other embodiments, the temperature sensor can be installed on the electromagnetic induction heating device, i.e., the temperature sensor can be integrated with the electromagnetic induction heating device. The detection device 16 can be a pressure sensor, but the pressure sensor needs to be installed inside the piping, which is more difficult to install than a temperature sensor.

[0034] When the Rankine cycle is in the initial operating stage, the energy of the waste heat source is not sufficiently stable, so that the refrigerant can be heated by the heating device 15 to ensure sufficient evaporation. Of course, in other embodiments, a valve can be provided on the piping downstream of the first evaporator 11, and the valve can be opened after the first evaporator 11 has absorbed a sufficient amount of heat and sufficiently evaporated the refrigerant, thereby similarly enabling the expander 12 to operate stably.

[0035] The refrigeration cycle 2 includes a compressor 21, a first heat exchanger 4, a throttling mechanism 23, and a second evaporator 24, which are connected in a circulating manner in sequence.

[0036] Furthermore, the refrigeration cycle 2 includes a subcooling controller 22. The subcooling controller 22 can further adjust the subcooling degree of the refrigerant in the refrigeration cycle to meet requirements.

[0037] In this embodiment, due to the presence of the first heat exchanger 4, the subcooling controller 22 has a slightly different function from the condenser in a general refrigeration system. In a general refrigeration system, a condenser converts a high-temperature, high-pressure gas refrigerant from a compressor into a liquid refrigerant, and a phase change occurs during the process. In this embodiment, the high-temperature, high-pressure refrigerant from the compressor 21 first passes through the first heat exchanger 4, and a part of the heat has already been thermally coupled to the refrigerant in the Rankine cycle. Furthermore, since the refrigerant flow rate in the Rankine cycle is greater than the refrigerant flow rate in the refrigeration cycle, the refrigerant in the refrigeration cycle has already undergone a phase change process from gas phase to liquid phase in the first heat exchanger 4. Therefore, the subcooling controller 22 only further adjusts the subcooling degree of the refrigerant in the refrigeration cycle, and no phase change process occurs.

[0038] In this embodiment, the refrigerant used in the Rankine circulation system 1 is different from the refrigerant used in the refrigeration cycle. As the refrigerant in the Rankine circulation system 1, refrigerants such as R245fa, R134a, R123, and R1233zd can be used, and as the refrigerant in the refrigeration cycle 2, refrigerants such as R134a, R404A, R448A, R455A, and R32 can be used.

[0039] This is due to the characteristics of the system itself. For example, the refrigerant evaporation temperature of the refrigeration cycle 2 is relatively low, usually several tens of degrees below zero. If this refrigerant is used in the Rankine cycle, it will already be in an evaporated state at room temperature, and the pressure will rise rapidly due to heating by waste heat energy, making the pipes of the Rankine cycle more likely to burst. In addition, using a high-strength material to prevent the pipes from bursting will increase costs. Conversely, the refrigerant evaporation temperature of the Rankine cycle system 1 is relatively high, usually above zero degrees, and if this refrigerant is used in the refrigeration cycle, it will not evaporate easily and will not provide a cooling effect.

[0040] In order to fully utilize the waste heat generated during the Rankine circulation and refrigeration cycle and to reduce the impact on the environment, the piping between the refrigerant pump 14 and the first evaporator 11 is thermally conductively connected to the first heat exchanger 4, and the piping between the expander 12 and the condenser 13 is thermally conductively connected to the piping between the second evaporator 24 and the compressor 21. In this embodiment, the piping between the expander 12 and the condenser 13 is thermally conductively connected to the piping between the second evaporator 24 and the compressor 21 via the second heat exchanger 3, but of course in other embodiments, it can also be connected via other structures such as heat pipes.

[0041] The first heat exchanger 4 includes a first fluid passage and a second fluid passage, the first fluid passage being connected between the compressor 21 and the throttling mechanism 23, and the second fluid passage being connected between the refrigerant pump 14 and the first evaporator 11. In this embodiment, the first fluid passage is connected between the compressor 21 and the subcooling degree controller 22.

[0042] The second heat exchanger 3 includes a first fluid passage and a second fluid passage, the first fluid passage is connected between the second evaporator 24 and the compressor 21, and the second fluid passage is connected between the expander 12 and the condenser 13. Here, the refrigerant in the first fluid passage of the first heat exchanger 4 and the first fluid passage of the second heat exchanger 3 is both a refrigerant of the refrigeration cycle 2, and the refrigerant in the second fluid passage of the first heat exchanger 4 and the second fluid passage of the second heat exchanger 3 is both a refrigerant of the Rankine circulation system 1.

[0043] First, the first heat exchanger 4 is used to cool the refrigerant flowing out from the compressor 21. That is, the refrigerant undergoes a heat dissipation process in the first heat exchanger 4, and the first heat exchanger 4 can recover the heat released from the refrigerant. In the Rankine circulation system 1, this heat can be used to heat the medium-temperature and medium-pressure refrigerant flowing out from the refrigerant pump 14. In this way, the temperature and pressure of the refrigerant can be increased, and the internal energy of the refrigerant entering the first evaporator 11 can be increased. When the low-quality heat source is unstable, a part of the insufficient heat can be compensated for. In the refrigeration cycle 2, the temperature of the refrigerant entering the subcooling controller 22 can be lowered, and the heat load of the subcooling controller 22 can be reduced.

[0044] Next, the second heat exchanger 3 is used to cool the refrigerant flowing out from the expander 12. That is, the refrigerant also undergoes a heat dissipation process in the second heat exchanger 3, and the second heat exchanger 3 can recover the heat released from the refrigerant. In the Rankine circulation process, the temperature of the refrigerant at the outlet of the expander 12 can be lowered, and the heat load of the condenser 13 can be reduced. In the refrigeration cycle 2, this heat is used to heat the low-temperature, low-pressure refrigerant flowing out from the second evaporator 24, and the refrigerant has a certain degree of superheat. That is, the refrigerant is further evaporated to a gas phase, the risk of liquid hammer in the compressor 21 can be reduced, and the reliability of the compressor 21 can be improved.

[0045] The first heat exchanger 4 and the second heat exchanger 3 sufficiently improve the operating reliability of the Rankine circulation system 1 and the refrigeration cycle 2, and enable mutual utilization of the waste heat generated by both systems, thereby improving the waste heat utilization rate, reducing the thermal load of the condenser 13 and the subcooling degree controller 22 themselves, as well as reducing the environmental impact of some of the waste heat, and reducing the energy consumption of additional devices required to absorb the thermal load.

[0046] The present invention further provides a waste heat recovery device (not shown). The waste heat recovery device is a heat exchanger that connects a pipe between the expander 12 and the condenser 13 and a pipe between the refrigerant pump 14 and the first evaporator 11. That is, the heat exchanger connects the pipe between the expander 12 and the condenser 13 and the pipe between the refrigerant pump 14 and the first evaporator 11, and is mainly used to cool the refrigerant flowing out from the expander 12.

[0047] In the Rankine circulation process, the temperature of the refrigerant at the outlet of the expander 12 can be reduced to reduce the heat load of the condenser 13, and at the same time, this heat can be used to heat the medium-temperature and medium-pressure refrigerant flowing out of the refrigerant pump 14. In this way, the temperature and pressure of the refrigerant can be increased, the internal energy of the refrigerant entering the first evaporator 11 can be increased, and a part of the heat shortage can be compensated for when the low-quality heat source is unstable.

[0048] The Rankine refrigeration cycle according to the refrigeration cycle 2 further includes a transmission mechanism 25 that connects the expander 12 and the compressor 21. The transmission mechanism 25 includes a drive shaft 251 that connects the expander 12 and the compressor 21. Therefore, the mechanical work generated by the expander 12 can be directly used as a power source for the compressor 21, and the energy efficiency can be maximized, the energy loss can be reduced, and the cooling effect can be improved. In addition, since the expander 12 and the compressor 21 are directly connected by the drive shaft 251, the Rankine refrigeration cycle can be made more compact, that is, the system can be made smaller, and the space occupied by the entire system can be reduced. In this embodiment, the drive shaft 251 has a split structure, but of course, in other embodiments, it may have an integral structure.

[0049] In order to enable the refrigeration cycle 2 to operate normally even when waste heat energy is not supplied to the Rankine cycle, i.e., when the refrigeration cycle loses its power source, the Rankine refrigeration cycle of the present invention further includes an electric power drive mechanism 26 mounted on the transmission mechanism 25 to drive the compressor 21. In this embodiment, the electric power drive mechanism 26 refers to a device that converts electric energy into mechanical energy.

[0050] As shown in Fig. 2 and Fig. 3, the electric power drive mechanism 26 includes a first clutch 261 attached to the drive shaft 251, a drive motor 262 cooperating with the first clutch 261, and a connection structure 263 connecting the first clutch 261 and the drive motor 262. The connection structure 263 may be two gears that mesh with each other, and the gears of the first clutch 261 and the drive shaft 251 are fixed to each other, but of course the two gears may be connected by a chain. Therefore, by connecting the electric power drive mechanism 26 to an external power source, the compressor 21 can be directly operated, and the refrigeration cycle 2 can be normally operated. Of course, the electric power drive mechanism 26 may be provided with its own power supply module (not shown).

[0051] In order to facilitate the normal operation of the first clutch 261, the power drive mechanism 26 further includes a cooperating structure 264 fixed to the first clutch 261. The cooperating structure 264 can be connected to the drive motor 262 via a structure such as a chain or a belt. In order to avoid interference of the first clutch 261 when the Rankine cycle supplies power to the refrigeration cycle, the cooperating structure 264 can be fixed in a predetermined position. Therefore, the drive shaft 251 is not interfered with when the first clutch 261 is not operating.

[0052] Specifically, in this embodiment, the drive shaft 251 includes a main drive shaft 2511 and a sub drive shaft 2512 which are connectable and separable from each other, the main drive shaft 2511 is connected to the expander 12, and the sub drive shaft 2512 is connected to the compressor 21, and the sub drive shaft 2512 may be the rotating shaft of the compressor 21 itself, or may be another structure connected to the rotating shaft of the compressor 21. The transmission mechanism 25 further includes a connecting device 252 for fixedly connecting the main drive shaft 2511 and the sub drive shaft 2512.

[0053] When it is necessary to operate the refrigeration cycle 2, the connecting device 252 can be controlled to fix the main drive shaft 2511 and the auxiliary drive shaft 2512. Then, when the expander 12 works, the compressor 21 also works at the same time. When it is not necessary to operate the refrigeration cycle 2, the connecting device 252 can be controlled to open so that the expander 12 works alone without affecting the compressor 21.

[0054] In this embodiment, the connecting device 252 includes a coupling 2521 fixed to one of the main driving shaft 2511 and the auxiliary driving shaft 2512, and a second clutch 2522 which cooperates with the other and is fixed to the coupling 2521. That is, when the coupling 2521 is fixed to the main driving shaft 2511, the second clutch 2522 is used to fix the auxiliary driving shaft 2512, and when the coupling 2521 is fixed to the auxiliary driving shaft 2512, the second clutch 2522 is used to fix the main driving shaft 2511.

[0055] Of course, in other embodiments, the drive shaft 251 may be an integral structure that directly connects the expander 12 and the compressor 21. That is, the expander 12 and the compressor 21 always operate or stop simultaneously. In this case, the connection device 252 is not necessary.

[0056] In this embodiment, when the first clutch 261 is mounted on the auxiliary drive shaft 2512 and the Rankine circulation system 1 cannot supply power to the refrigeration cycle 2, the connection device 252 is controlled to release the fixation between the main drive shaft 2511 and the auxiliary drive shaft 2512 to separate them, and then the first clutch 261 is controlled to fix the auxiliary drive shaft 2512, and the first clutch 261 and the auxiliary drive shaft 2512 are rotated by the drive motor 262, so that the compressor 21 can finally operate normally.

[0057] Another embodiment of a connecting device 252 according to the present invention is provided as shown in Fig. 4 to Fig. 6. The connecting device 252 includes a first gear 2523 mounted on a main driving shaft 2511 and a second gear 2524 mounted on a secondary driving shaft 2512 and cooperating with the first gear 2523. The first gear 2523 and the second gear 2524 have different diameters. The second clutch 2522 is fixed to the first gear 2523, and the first gear 2523 drives the main driving shaft 2511 to rotate through the second clutch 2522.

[0058] The first gear 2523 and the second gear 2524 can be directly meshed with each other or connected via a structure such as a chain. In the connection device 252 of the second embodiment of the present invention shown in Figures 4 and 5, when the diameter of the first gear 2523 is larger than that of the second gear 2524, an acceleration effect is obtained, and in the connection device 252 of the third embodiment of the present invention shown in Figure 6, when the diameter of the second gear 2524 is smaller than that of the first gear 2523, a deceleration effect is obtained.

[0059] Therefore, different connection devices 252 can be selected according to the actual situation, and of course the transmission can be selected, and the speed can be freely adjusted, so that the rotation speed of the compressor 21 can be adjusted, and the cooling efficiency can be further adjusted. In addition, when the torque of the auxiliary drive shaft 2512 of the compressor 21 is large, the compressor 21 can be prevented from being damaged by the deceleration.

[0060] In this embodiment, the first clutch 261 and the second clutch 2522 are both electromagnetic clutches, of which the first clutch 261 is an energized clutch and the second clutch 2522 is an energized clutch. That is, the first clutch 261 is fixed to the auxiliary drive shaft 2512 only when energized, and the second clutch 2522 is fixed to the main drive shaft 2511 only when de-energized. Therefore, the first clutch 261 and the second clutch 2522 can share an external power source or can be centrally powered by the power source module of the electric drive mechanism 26. Therefore, the control is very simple. Of course, the first clutch 261 and the second clutch 2522 can be powered by different power sources, that is, they do not need to be centrally powered.

[0061] Specific operation process: When the Rankine cycle is operating normally, no power supply is required, and the expander 12 can directly drive the compressor 21. When the Rankine cycle cannot operate normally, power is supplied to the first clutch 261, the second clutch 2522, and the electric power drive mechanism 26. At this time, the first clutch 261 is fixed to the auxiliary drive shaft 2512, and the second clutch 2522 is released from the fixation to the main drive shaft 2511. As a result, the drive motor 262 can rotate and drive the compressor 21, and the expander 12 does not rotate.

[0062] In the present invention, when the Rankine circulation system 1 does not have a waste heat source, in addition to the above-mentioned method, the refrigerant can be continuously evaporated by the heating device 15 to continuously operate the Rankine circulation. That is, the expander 12 outputs power continuously and effectively. The heating device 15 here is a representative heating method, and can be replaced with other heating methods, so that the Rankine circulation can be normally operated and power output can be maintained even when there is no waste heat source.

[0063] Through research by the inventors, it was found that in conventional refrigerated vehicles, a damper is provided to control the supply of cold heat from the refrigeration cycle 2 to the refrigerated box, but the damper is an electronic component and has poor stability during transportation. In this embodiment, an inverter-controlled refrigerant pump is adopted as the refrigerant pump 14, and according to the required amount of cooling, the refrigerant flow rate is adjusted by the refrigerant pump 14 to adjust the output of the expander 12, and the operating output of the compressor 21 is further controlled to achieve the purpose of adjusting the amount of cooling.

[0064] Specifically, the use of the inverter-controlled refrigerant pump 14 allows for appropriate adjustment within a certain range according to actual operating requirements, thereby improving the practicality of the Rankine circulation system-refrigeration system. By adjusting the refrigerant flow rate of the Rankine circulation, the amount of high-temperature, high-pressure refrigerant supplied to the expander 12 can be adjusted, and the rotation speed of the expander 12 can be adjusted in real time, and further the rotation speed of the compressor 21 can be adjusted, ultimately adjusting the cooling effect.

[0065] In addition, the refrigerant pump 14 can determine how much refrigerant can be evaporated based on the current amount of waste heat energy, and adjust the rotation speed of the refrigerant pump 14 based on the amount of refrigerant that can be evaporated, so that the entire system can be in an optimal operating state. On the one hand, the waste heat energy in the current circulation can be fully utilized, and the amount of evaporation of the refrigerant can be maximized under the waste heat energy conditions, thereby ensuring that the expander 12 can stably generate the maximum mechanical work under those conditions. On the other hand, it can be avoided that the refrigerant cannot be sufficiently evaporated due to an excessive refrigerant flow rate, which further affects the stable operation of the expander 12.

[0066] In addition, when the refrigerant flow rate is excessive, the refrigerant can be further heated by the electric heating device 15 of the present invention to ensure sufficient evaporation of the refrigerant entering the expander 12, but this method requires additional power consumption and increases costs. Therefore, by providing the inverter-controlled refrigerant pump 14, in the subsequent circulation process (other than the initial operation stage), when the waste heat energy is relatively stable, it is not necessary to use the electric heating device 15, thereby saving power and reducing costs.

[0067] The Rankine refrigeration cycle of the present invention can also be applied to cold chain transportation equipment. In this embodiment, the Rankine refrigeration cycle is applied to a refrigerated car (not shown), which includes a refrigerated car body and a refrigerated box 5 installed on the refrigerated car body, and the refrigerated car further includes the above-mentioned Rankine refrigeration cycle 2 for supplying cold heat to the refrigerated box 5, and a heat transfer mechanism for connecting the waste heat source of the refrigerated car and the first evaporator 11.

[0068] The refrigerated vehicle includes an engine and a heat dissipation mechanism for cooling the engine, the heat dissipation mechanism includes a pipe through which a coolant flows, and the heat transfer mechanism connects the pipe and the first evaporator 11. The heat transfer mechanism may be a heat transfer tube (i.e., indirect connection), or may have a structure that directly connects the pipe and the first evaporator 11 (i.e., direct connection). In this case, the coolant is an antifreeze liquid.

[0069] When the refrigerated vehicle is in the process of transportation, the engine generates a large amount of waste heat, so the waste heat is recovered by the Rankine refrigeration cycle 2, and the waste heat is converted into the power of the refrigeration cycle to supply cold heat to the refrigerated box 5, and the thermal energy is converted into mechanical energy to realize the power combination. This allows the cold heat to be continuously supplied to the refrigerated box 5 to ensure the refrigeration effect, and further reduces the emission of waste heat to reduce the impact on the environment. At the same time, there is no need to use the electricity of the refrigerated vehicle itself, and energy consumption can be reduced. Of course, heat can also be taken from the exhaust pipe. For example, the waste heat source temperature of 100°C can be converted to a refrigerant temperature of -18°C, so that the refrigerant can supply cold heat to the refrigerated box 5. In addition, the energy of a Rankine circulation refrigerant with a refrigeration capacity of 30 kW or more and the energy of a refrigeration cycle with a refrigeration capacity of 3 kW are generally complementary to each other.

[0070] The specific process is as follows: First, after the high-temperature antifreeze exchanges heat with the refrigerant in the first evaporator 11, the refrigerant vapor enters the expander 12 and rotates the scroll plate at high speed. Since the scroll plate rotating at high speed and the main shaft of the compressor 21 are coaxial, the expander 12 drives the compressor 21 to operate.

[0071] Secondly, after the compressor 21 compresses the refrigerant, the refrigerant is discharged in a high-temperature, high-pressure state. The high-temperature, high-pressure refrigerant enters the first heat exchanger 4 and exchanges heat with the low-temperature refrigerant in the Rankine cycle. The refrigerant in the refrigeration cycle condenses into liquid and releases heat to preheat the low-temperature refrigerant in the Rankine cycle. As a result, the refrigerant in the Rankine cycle enters the first evaporator 11 at a higher temperature.

[0072] Thirdly, the refrigerant of the refrigeration cycle enters the second evaporator 24, exchanges heat with the refrigerant in the second evaporator 24, then enters the second heat exchanger 3 to exchange heat with the refrigerant from the outlet of the expander 12, and ensures that the refrigerant entering the compressor 21 in the refrigeration cycle has a certain degree of superheat before entering the compressor 21. The refrigerant of the Rankine cycle that is not sufficiently cooled in the second heat exchanger 3 further enters the condenser 13 to be cooled, and after being cooled to a saturated liquid state, the liquid refrigerant is sent to the first evaporator 11 by the refrigerant pump 14, where it further absorbs heat from the high-temperature antifreeze liquid to complete the circulation.

[0073] In this embodiment, the refrigerated vehicle further includes a cold storage device 6 arranged in cooperation with the refrigerated box 5, and the second evaporator 24 is connected to the cold storage device 6 to store cold energy in the cold storage device. Therefore, even if the temperature in the refrigerated box 5 is appropriate and no cooling is required, the Rankine refrigeration cycle 2 can still store cold energy in the cold storage device 6. Therefore, when cold energy is stored in the cold storage device 6 and the temperature in the refrigerated box 5 rises, the cold energy can be released to the refrigerated box 5 through the cold storage device 6 to lower the temperature, and at the same time, the Rankine refrigeration cycle 2 can continue to store and replenish cold energy in the cold storage device 6. In this way, the refrigeration time can be effectively extended and the quality of goods and ingredients can be ensured during long-distance transportation.

[0074] When the refrigerated vehicle is operating, it can absorb waste heat to supply energy to the Rankine circulation system 1; when the refrigerated vehicle is stopped, power can be continuously supplied to the electric heating device 15 via a commercial power source or a standby power source, thereby ensuring the continuous operation of the Rankine circulation system 1 and the normal operation of the refrigeration cycle 2, thereby maintaining the temperature inside the refrigerated box 5 at a low level, and ensuring the freshness of the transported products.

[0075] Generally, since a refrigerated vehicle is mostly in operation, the first evaporator 11 can be a regular evaporator. In comparison, since the stop time of the refrigerated vehicle is short, the operation time of the electric heating device 15 is much shorter than that of the first evaporator 11, and since both the electric heating device 15 and the first evaporator 11 supply energy to the refrigerant, the electric heating device 15 can also be considered as an emergency evaporator.

[0076] Of course, when the refrigerated car is started or for a short time immediately after it is started, the generated waste heat is insufficient to drive the expander 12, and at this time, the refrigerant can be heated by the electric heating device 15, thereby ensuring normal operation of the Rankine circulation in the initial stage, and when the refrigerated car starts to generate sufficient waste heat, the electric heating device 15 can be stopped. Also, since the time until the refrigerated car generates sufficient waste heat is relatively short, the required operating time of the electric heating device 15 is also relatively short, and excessive power is not wasted.

[0077] Therefore, the waste heat generated when the refrigerated vehicle starts is already utilized by the Rankine circulation, which maximizes the utilization of the waste heat and greatly reduces environmental pollution. Also, the provision of the electric heating device 15 allows the effective utilization of the small amount of waste heat in the initial stage and prevents it from being wasted.

[0078] Of course, in other embodiments, for example when the transit time of the refrigerated vehicle is relatively short, the Rankine cycle can also be used to generate electricity to power equipment on the refrigerated vehicle, thereby reducing energy consumption.

[0079] In summary, by providing the electric heating device 15 between the refrigerant pump 14 and the expander 12, the Rankine cycle system 1 of the present invention can continue to supply energy to the Rankine cycle via the electric heating device 15 even when there is no waste heat source, thereby enabling the expander 12 to output mechanical work continuously and effectively, and also enabling the Rankine cycle to operate normally even when there is no waste heat source, and further enabling it to adapt to a wider range of operating conditions.

[0080] The above embodiments are for illustrating the technical solutions of the present invention, and are not intended to limit the same. Although the present invention has been described in detail with reference to more preferred embodiments, it should be understood that those skilled in the art can make modifications or equivalent substitutions to the technical solutions of the present invention, none of which departs from the spirit and scope of the technical solutions of the present invention.

Claims

1. A Rankine circulation system in which a first evaporator, an expander, a condenser, and a refrigerant pump are sequentially connected in a circulating manner, A Rankine circulation system having at least two types of heating methods for supplying heat to the first evaporator.

2. 2. The Rankine circulation system according to claim 1, wherein the heating method is waste heat heating, electric heating, combustion heating, geothermal heating, or residual heat heating.

3. The compressor further includes a heating device connected between the refrigerant pump and the expander to heat the refrigerant. The heating device is an electromagnetic induction heating device, and the electromagnetic induction heating device includes an electromagnetic heating controller and an electromagnetic induction coil connected to the electromagnetic heating controller, and the electromagnetic induction coil is disposed outside a pipe between the first evaporator and the expander.

2. The Rankine circulation system according to claim 1, wherein the heating device is a combustion heating device or a heat radiation device.

4. The Rankine circulation system according to claim 1 , further comprising a detection device disposed between the heating device and the expander and detecting a temperature and / or a pressure of the refrigerant.

5. 2. The Rankine circulation system according to claim 1, wherein the refrigerant pump is an inverter-controlled refrigerant pump.

6. A Rankine refrigeration cycle comprising: a refrigeration cycle in which a compressor, a first heat exchanger, a throttling mechanism, and a second evaporator are sequentially connected in a circulating manner; and the Rankine circulation system according to claim 1, further comprising a transmission mechanism connecting the expander and the compressor.

7. the first heat exchanger includes a first fluid passage and a second fluid passage, the first fluid passage being connected between the compressor and the throttling mechanism, and the second fluid passage being connected between the refrigerant pump and the first evaporator; 7. The Rankine-refrigeration cycle according to claim 6, further comprising a second heat exchanger, the second heat exchanger including a first fluid passage and a second fluid passage, the first fluid passage being connected between the second evaporator and the compressor, and the second fluid passage being connected between the expander and the condenser.

8. The Rankine refrigeration cycle according to claim 6, wherein the compressor has a first operating state in which it is connected to the expander via the transmission mechanism, and a second operating state in which it is connected to an electric power driving mechanism.

9. The transmission mechanism includes a main drive shaft connected to the expander and an auxiliary drive shaft connected to the compressor, the main drive shaft and the auxiliary drive shaft being detachably connected to each other, The Rankine-refrigeration cycle according to claim 8, wherein the electric power drive mechanism comprises a first clutch attached to the auxiliary drive shaft, a drive motor cooperating with the first clutch, and a connection structure connecting the first clutch and the drive motor.

10. The transmission mechanism further includes a connection device for connecting the main drive shaft and the auxiliary drive shaft, the connection device including a coupling fixed to one of the main drive shaft and the auxiliary drive shaft, and a second clutch cooperating with the other of the main drive shaft and fixed to the coupling. Alternatively, the transmission mechanism further includes a connection device for connecting the main drive shaft and the auxiliary drive shaft, the connection device including a coupling fixed to one of the main drive shaft and the auxiliary drive shaft, and a second clutch cooperating with the other of the main drive shaft and fixed to the coupling, the connection device including a first gear attached to the main drive shaft and a second gear attached to the auxiliary drive shaft and cooperating with the first gear, the first gear and the second gear having different diameters. Alternatively, the transmission mechanism further includes a connection device for connecting the main drive shaft and the auxiliary drive shaft, the connection device including a coupling fixed to one of the main drive shaft and the auxiliary drive shaft, and a second clutch cooperating with the other of the main drive shaft and fixed to the coupling, the connection device including a first gear attached to the main drive shaft, a second clutch fixed to the first gear, and a second gear attached to the auxiliary drive shaft and cooperating with the first gear, the first gear and the second gear having different diameters, and the first gear rotates and drives the main drive shaft via the second clutch. The Rankine refrigeration cycle of claim 9.

11. 10. The Rankine refrigeration cycle according to claim 9, wherein the first clutch is an energized clutch, and the second clutch is an energized clutch.

12. The Rankine-refrigeration cycle according to claim 12, wherein the electric power drive mechanism further comprises a power supply module that supplies electric power to the first clutch, the second clutch, and the drive motor.

13. The Rankine refrigeration cycle according to claim 9, further comprising a subcooling controller connected between the first heat exchanger and the throttling mechanism.

14. A refrigerated car equipped with a refrigerated box, A refrigerated vehicle further comprising the Rankine refrigeration cycle according to claim 6, wherein a first evaporator of the Rankine circulation system is thermally connected to a waste heat source of the refrigerated vehicle via a heat conductive structure, and an evaporator of the refrigeration cycle supplies cold heat to the refrigerated box via a cooling unit.

15. an engine; and a cooling mechanism for cooling the engine, the heat transfer mechanism connecting the cooling mechanism and the first evaporator; Alternatively, the Rankine refrigeration cycle according to claim 14, further comprising a cold storage device for supplying cold heat to the refrigerated box, the second evaporator being thermally conductively connected to the cold storage device.

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