Hydraulic oil radiator, hydraulic oil heat recovery system and construction machine

Abstract

The present disclosure relates to a hydraulic oil radiator for a construction machine, a hydraulic oil heat recovery system, and a construction machine. The hydraulic oil radiator comprises: a plurality of hydraulic oil channels arranged in parallel at intervals, and a hydraulic oil inflow chamber and a hydraulic oil outflow chamber arranged at both ends of the hydraulic oil channels and communicated with them, wherein the hydraulic oil channels each comprise a first section located upstream and a second section located downstream along a flow direction of the hydraulic oil; in a region corresponding to the first sections, cooling liquid channels in which cooling liquid flows are arranged outside the hydraulic oil channels, and in the first sections, the hydraulic oil exchanges heat with the cooling liquid; in a region corresponding to the second sections, radiating fins that define cooling airflow channels are arranged outside the hydraulic oil channels, and in the second sections, the hydraulic oil exchanges heat with cooling airflow. The hydraulic oil radiator in the present disclosure can reduce the load of the hydraulic oil radiator, which is conducive to reducing the size of the radiator and achieving the energy-saving goal.

Description

[0001] 24-0317WO01

[0002] Description

[0003] HYDRAULIC OIL RADIATOR, HYDRAULIC OIL HEAT RECOVERY SYSTEM AND CONSTRUCTION MACHINE

[0004] Technical Field

[0005] The present disclosure relates to the technical field of heat dissipation of construction machines, in particular to a hydraulic oil radiator for a construction machine, a hydraulic oil heat recovery system comprising the hydraulic oil radiator and a construction machine comprising the hydraulic oil heat recovery system.

[0006] Background Art

[0007] A hydraulic oil radiator is used in a construction machine such as an excavator, a pile driver, a paver, an air compressor and a road roller, where hydraulic oil is used as a force transmission medium to supply power to a working device. The hydraulic oil radiator is mainly used in a circuit of a hydraulic system of a construction machine. When working, the high-temperature oil in the hydraulic system flows through the hydraulic oil radiator and exchanges heat efficiently in the radiator with the airflow passing through the radiator to reduce the oil temperature to the working temperature, thus ensuring continuous and normal operation of the machine.

[0008] The heat emitted from the hydraulic oil radiator is discharged into the air, resulting in energy waste. In addition, due to the limited space of the radiator, the hydraulic oil radiator requires a compact design. Requiring both compact design and high energy efficiency, the new energy construction machine faces a great challenge in the design of the hydraulic oil radiator. 24-0317WO01

[0009] Summary of the Invention

[0010] An object of the present disclosure is to solve at least one of the above problems and / or other problems existing in the prior art.

[0011] To achieve the above object, according to an aspect of the present disclosure, a hydraulic oil radiator for a construction machine is provided, comprising: a plurality of hydraulic oil channels arranged in parallel at intervals, and a hydraulic oil inflow chamber and a hydraulic oil outflow chamber arranged at both ends of the hydraulic oil channels and communicated with them, wherein the hydraulic oil channels each comprise a first section located upstream and a second section located downstream along a flow direction of the hydraulic oil; in a region corresponding to the first sections, cooling liquid channels in which cooling liquid flows are arranged outside the hydraulic oil channels, and in the first sections, the hydraulic oil exchanges heat with the cooling liquid; in a region corresponding to the second sections, radiating fins that define cooling airflow channels are arranged outside the hydraulic oil channels, and in the second sections, the hydraulic oil exchanges heat with cooling airflow.

[0012] The hydraulic oil radiator according to the present disclosure has a compact structure and enables effective recovery of a part of heat dissipated by the hydraulic oil. The hydraulic oil heat recovery portion and the hydraulic oil heat dissipation portion are integrated on a single heat exchanger entity, avoiding a complicated circuit involving a plurality of heat exchangers and the resulting complicated control, and providing great freedom for the arrangement of the hydraulic oil radiator and the construction machine cooling system. In addition, the existing hydraulic oil radiator can be retrofitted at low cost for a high energysaving effect.

[0013] According to an embodiment of the present disclosure, at two ends of the cooling liquid channels, a cooling liquid inflow chamber and a cooling liquid outflow chamber are provided, which are communicated with the cooling liquid channels, wherein the cooling liquid inflow chamber is close to 24-0317WO01 downstream ends of the first sections of the hydraulic oil channels, and the cooling liquid outflow chamber is close to upstream ends of the first sections of the hydraulic oil channels. Through this configuration, the size of the hydraulic oil radiator is reduced and the heat exchange efficiency is improved by using the efficient counter-current heat exchange method.

[0014] According to an embodiment of the present disclosure, the cooling liquid inflow chamber is arranged on a first face side of the hydraulic oil radiator, the cooling liquid outflow chamber is arranged on a second face side of the hydraulic oil radiator, and the first face side and the second face side are opposite to each other in a thickness direction of the hydraulic oil radiator that is perpendicular to an extension direction of the hydraulic oil channels and a parallel arrangement direction of the hydraulic oil channels. In this way, the cooling liquid inflow chamber and the cooling liquid outflow chamber can be arranged advantageously by employing the available space of the hydraulic oil radiator, making the structure of the entire hydraulic oil radiator more compact.

[0015] According to an embodiment of the present disclosure, a fan is arranged on the first face side of the hydraulic oil radiator in the region corresponding to the second sections of the hydraulic oil channels, so as to force the airflow to pass through cooling airflow channels and form a cross flow with a hydraulic oil flow in the second sections of the hydraulic oil channels.

[0016] According to an embodiment of the present disclosure, the hydraulic oil inflow chamber is located at an upper end of the hydraulic oil radiator, the hydraulic oil outflow chamber is located at a lower end of the hydraulic oil radiator, an outer wall of the hydraulic oil inflow chamber located on the first face side of the hydraulic oil radiator is provided with an oil inlet, and an outer wall of the hydraulic oil outflow chamber located on the first face side of the hydraulic oil radiator is provided with an oil outlet. In this way, the hydraulic oil pipelines can be connected conveniently. 24-0317WO01

[0017] According to a further aspect of the present disclosure, a hydraulic oil heat recovery system for a construction machine is provided, comprising a hydraulic oil radiator as described above and a heating device for heating a cab of the construction machine, wherein the heating device is in fluid connection with the hydraulic oil radiator, so that a heat-carrying medium flowing through the heating device flows into the cooling liquid channels of the hydraulic oil radiator as the cooling liquid, and the cooling liquid flowing out of the cooling liquid channels of the hydraulic oil radiator flows into the heating device as the heatcarrying medium. In this way, the recovered heat can be used for heating the cab, thus improving the energy-saving effect of the whole machine.

[0018] According to an embodiment of the present disclosure, a control valve is provided in a pipe section located upstream of the hydraulic oil radiator and downstream of the heating device, wherein the control valve is signal- connected to a controller of the hydraulic oil heat recovery system and is opened or closed according to an opening or closing instruction from the controller, thus achieving fluid communication or disconnection between the heating device and the hydraulic oil radiator.

[0019] According to an embodiment of the present disclosure, the hydraulic oil heat recovery system comprises: a first temperature sensor for detecting a hydraulic oil inflow temperature of the hydraulic oil entering the hydraulic oil radiator and a second temperature sensor for detecting a cooling liquid inflow temperature of the cooling liquid entering the cooling liquid channels of the hydraulic oil radiator, the controller being signal-connected to the first and second temperature sensors, and being adapted to close the control valve to disconnect the fluid communication between the heating device and the hydraulic oil radiator when a temperature difference between the hydraulic oil inflow temperature and the cooling liquid inflow temperature drops to a first preset value, and to open the control valve in response to a heating request to enable fluid communication between the heating device and the hydraulic oil 24-0317WO01 radiator when the temperature difference between the hydraulic oil inflow temperature and the cooling liquid inflow temperature rises to a second preset value, wherein the first preset value is less than the second preset value. In this way, certain control flexibility will be allowed, making the machine easy to adopt heating modes under different working conditions.

[0020] According to an embodiment of the present disclosure, the hydraulic oil heat recovery system comprises a third temperature sensor for detecting a hydraulic oil outflow temperature of the hydraulic oil radiator, the controller being adapted to increase a rotation speed of the fan for forcing the cooling airflow to pass through the cooling airflow channels in response to the hydraulic oil outflow temperature measured by the third temperature sensor reaching a first temperature limit when the control valve is in an open state, and to increase the rotation speed of the fan in response to the hydraulic oil outflow temperature measured by the third temperature sensor reaching a second temperature limit when the control valve is in a closed state, wherein the first temperature limit is greater than the second temperature limit. In this way, the outflow temperature of the hydraulic oil can be monitored conveniently to ensure normal operation of the hydraulic system.

[0021] According to an embodiment of the present disclosure, the hydraulic oil heat recovery system includes a PTC heater for auxiliary heating, which is arranged in a branch parallel to the branch where the cooling liquid channels of the hydraulic oil radiator is located. For a new energy construction machine, the hydraulic oil heat recovery system advantageously reduces the use frequency of the PTC heater, which is conducive to achieving the energy-saving goal.

[0022] According to a still further aspect of the present disclosure, a construction machine comprising a hydraulic oil heat recovery system as described above is provided. 24-0317WO01

[0023] The hydraulic oil radiator of the present disclosure integrates the function of hydraulic oil heat dissipation and the function of cab heating in one compact heat exchanger. The heat exchanger is designed with a first heat dissipation core portion in a hydraulic oil-cooling liquid counter-current heat exchange configuration and a second heat dissipation core portion in a hydraulic oil-air cross-flow heat exchange configuration, which is conducive to separate control of the heating demand and the hydraulic oil heat dissipation demand. Recycling part of the heat of the hydraulic oil effectively, the hydraulic oil heat recovery system according to the present disclosure reduces the load of the hydraulic oil radiator, improves its overall compactness, and avoids such problems as difficult arrangement and high control cost resulting from too many circuits or control valves existing in the prior art.

[0024] Brief Description of the Drawings

[0025] The features and advantages of the present disclosure will be clearly understood through a detailed description provided below with reference to the accompanying drawings. It will be appreciated that the following drawings are only schematic and not necessarily drawn to scale, so they cannot be regarded as limitations of the present disclosure.

[0026] Fig. l is a perspective view of a hydraulic oil radiator according to an exemplary embodiment of the present disclosure.

[0027] Fig. 2 is a perspective view from another angle of hydraulic oil channels of the hydraulic oil radiator shown in fig. 1.

[0028] Fig. 3 is a principle diagram of a hydraulic oil radiator with a composite configuration according to an embodiment of the present disclosure.

[0029] Fig. 4 is a schematic diagram of a hydraulic oil heat recovery system according to an exemplary embodiment of the present disclosure. 24-0317WO01

[0030] List of Reference Signs

[0031] 1. Hydraulic oil radiator; 10. Hydraulic oil channel; 101. First section; 102. Second section; 12. Hydraulic oil inflow chamber; 13. Hydraulic oil outflow chamber; 4. Fan; 5. Cooling liquid channel; 6. Cooling liquid inflow chamber; 7. Cooling liquid outflow chamber; 8. Cooling airflow channel; F. Radiating fins; 21. Oil inlet; 31. Oil outlet; 61. Liquid inlet; 71. Liquid outlet; S. Hydraulic oil heat recovery system; 200. Heating device; 300. First temperature sensor; 400. Second temperature sensor; 500. Control valve; 600. Third temperature sensor; 700. PTC heater; 800. Fourth temperature sensor; 101c. First heat dissipation core portion; 102c. Second heat dissipation core portion.

[0032] Detailed Description of the Embodiments

[0033] Embodiments of the present disclosure are described below with reference to the drawings. In the following description, numerous specific details are set forth in order to make those skilled in the art fully understand and implement the present disclosure. However, it will be apparent to those skilled in the art that the present disclosure may be implemented without some of these specific details. Furthermore, it will be appreciated that the present disclosure is not limited to the specific embodiments described herein. On the contrary, any combination of features and elements described below can be used to implement the present disclosure, regardless of whether they relate to different embodiments. Therefore, the following aspects, features, embodiments and advantages are for illustration only, and should not be regarded as elements or limitations of the claims, unless explicitly stated in the claims.

[0034] Terms such as "first" and "second" are used herein to describe the elements of the present application, but they are only used to distinguish individual elements, and are not used to limit the nature, order or number of the elements. The terms "comprising", "including" and “having” are used to indicate 24-0317WO01 an open-ended inclusion, and mean that there may be other elements / components besides the listed elements / components.

[0035] Figs. 1 and 2 show a hydraulic oil radiator 1 for a construction machine according to an embodiment of the present disclosure. With reference to fig. 3, the hydraulic oil radiator 1 according to this embodiment may include a plurality of hydraulic oil channels 10 arranged in parallel at intervals, and a hydraulic oil inflow chamber 12 and a hydraulic oil outflow chamber 13 respectively communicated with the plurality of hydraulic oil channels 10. In the embodiment shown in figs. 1 to 3, the hydraulic oil channel 10 extends in a Z direction (vertical direction) from top to bottom. The hydraulic oil channels 10 may, for example, be implemented as channels inside a plurality of flat tubes arranged in parallel in an X direction (parallel arrangement direction). The hydraulic oil inflow chamber 12 is arranged at upper ends of the plurality of hydraulic oil channels 10. The hydraulic oil inflow chamber 12 is provided with an oil inlet 21. As shown in fig. 1, the oil inlet 21 is provided on an outer wall of a first face side in a thickness direction (Y direction) of the hydraulic oil inflow chamber 12. The hydraulic oil outflow chamber 13 is arranged at lower ends of the plurality of hydraulic oil channels 10. The hydraulic oil outflow chamber 13 is provided with an oil outlet 31. As shown in fig. 1, the oil outlet 31 is provided on an outer wall of a first face side in a thickness direction of the hydraulic oil outflow chamber 13. Thus, the pipelines for hydraulic oil are connected with the oil inlet and the oil outlet respectively on the same side of the hydraulic oil radiator.

[0036] With reference to figs. 1 to 3, each hydraulic oil channel 10 may include a first section 101 located upstream and a second section 102 located downstream along the flow direction of the hydraulic oil (i.e., Z direction). In a region corresponding to the first sections 101, a cooling liquid channel 5 in which cooling liquid (for example, water) flows is provided between adjacent hydraulic oil channels 10, and the hydraulic oil in the first sections 101 of the hydraulic oil 24-0317WO01 channels 10 exchanges heat with the cooling liquid in the cooling liquid channels 5. Thereby, a first heat dissipation core portion 101c of the hydraulic oil radiator is formed. In a region corresponding to the second sections 102, radiating fins F defining cooling airflow channels 8 are provided between adjacent hydraulic oil channels 10. The cooling airflow channels 8 extend in the Y direction. The first face side in the thickness direction of the hydraulic oil radiator 1 is covered with a fan cover in the region corresponding to the second sections 102, and a fan 4 is arranged in the fan cover, and cooling airflow is forced into the cooling airflow channels 8 by the fan 4. When the cooling airflow passes through the cooling airflow channels 8, it exchanges heat with the hydraulic oil in the second sections 102 of the hydraulic oil channels in a cross-flow manner, so as to cool the hydraulic oil. Thereby, a second heat dissipation core portion 102a of the hydraulic oil radiator is formed.

[0037] The first heat dissipation core portion 101c and the second heat dissipation core portion 102c are formed as two portions of the integral hydraulic oil radiator 1, and there is no intermediate chamber for the circulation of hydraulic oil between the two portions. That is, the hydraulic oil channel 10 in the hydraulic oil radiator 1 or a tube or plate member for defining the hydraulic oil channel extends all the way from the hydraulic oil inflow chamber to the hydraulic oil outflow chamber without interruption or partition. In a preferred embodiment, the first heat dissipation core portion 101c can be designed as a plate-fin heat exchange core, wherein hydraulic oil channels are defined between plate pairs, and the space between adjacent plate pairs is partitioned into a plurality of cooling liquid channels (or microchannels) by vertically extending fins. The second heat dissipation core portion 102c can be designed as a plate-fin heat exchange core, in which the space between adjacent plate pairs is partitioned into a plurality of cooling airflow channels by radiating fins.

[0038] At two ends of the cooling liquid channels 5 along the cooling liquid flow direction, a cooling liquid inflow chamber 6 and a cooling liquid 24-0317WO01 outflow chamber 7 are provided, which are in fluid communication with the cooling liquid channels 5, as shown in figs. 1 to 3. In the illustrated embodiment, the first face side of the cooling liquid inflow chamber 6 adjacent to the downstream of the first section 101 of the hydraulic oil channels 10 in the thickness direction of the hydraulic oil radiator is provided with a liquid inlet 61. The second face side of the cooling liquid outflow chamber 7 adjacent to the upstream of the first section 101 of the hydraulic oil channel 10 in the thickness direction of the hydraulic oil radiator is provided with a liquid outlet 71. The first face side and the second face side are opposite to each other in the thickness direction of the hydraulic oil radiator. In an embodiment, the hydraulic oil radiator can be placed in a posture where the first face side and the second face side are the front side and the rear side, respectively. Thus the hydraulic oil flows from top to bottom in the hydraulic oil channels 10, the cooling liquid flows from bottom to top in the cooling liquid channels 5, and the cooling airflow flows in the front-rear direction. Because the flow direction of the cooling liquid is opposite to that of the hydraulic oil, the cooling liquid and hydraulic oil exchange heat in a counter-current manner. The counter-current heat exchange method significantly improves the heat exchange efficiency, and is conducive to the compact design of the radiator. The hydraulic oil and cooling airflow form a cross flow in the flow direction, which is conducive to producing a significant cooling effect at less fan power consumption.

[0039] Fig. 4 shows a hydraulic oil heat recovery system S according to the present disclosure. The hydraulic oil heat recovery system includes the aforesaid hydraulic oil radiator 1 and a heating device 200 for heating the cab of the construction machine. The cooling liquid channels of the hydraulic oil radiator 1 is fluidly connected with the heating device 200, so that the liquid (heat-carrying medium) flowing through the heating device 200 releases heat and flows out of the heating device 200, and flows into the first heat dissipation core portion 101c of the hydraulic oil radiator 1 as the cooling liquid. On the contrary, 24-0317WO01 the cooling liquid absorbs heat from the hydraulic oil in the hydraulic oil channels 10 when flowing through the cooling liquid channels of the first heat dissipation core portion 101c of the hydraulic oil radiator 1, and flows out of the hydraulic oil radiator 1 after being heated, and then flows into the heating device 200 as the heat-carrying medium. The heating device includes a heater core. The heater core and an evaporator in the cab air-conditioning system are both arranged in a ventilation duct in communication with the cab for adjusting the temperature in the cab. During heating, the heat-carrying medium gives off heat at the heater core, heating the airflow supplied to the cab and forming warm air.

[0040] In the hydraulic oil heat recovery system S, the cooling liquid circulates, absorbs heat at the hydraulic oil radiator 1, and releases heat at the heating device 200, thereby recycling part of heat released from the hydraulic oil. Therefore, while improving the cooling effect of the hydraulic oil, the hydraulic oil heat recovery system heats the cab, making the environment within the cab more comfortable.

[0041] With reference to fig. 4, the hydraulic oil from the hydraulic system of the construction machine enters the hydraulic oil radiator 1 along an inflow pipe section A. The inflow pipe section A leads into the hydraulic oil inflow chamber. A first temperature sensor 300 is provided on the inflow pipe section A for detecting the hydraulic oil inflow temperature of the hydraulic oil entering the hydraulic oil channels 10 of the hydraulic oil radiator 1. The hydraulic oil flowing out of the hydraulic oil outflow chamber of the hydraulic oil radiator 1 returns to the hydraulic system through an outflow pipe section B.

[0042] A control valve 500 is provided in the fluid pipe section C for the cooling liquid, which is connected between the downstream of the heating device 200 and the first heat dissipation core portion 101c of the hydraulic oil radiator 1. An exhaust tank / expansion tank is provided in the fluid pipe section D for the cooling liquid connected between the cooling liquid outflow chamber downstream of the first heat dissipation core portion 101c of the hydraulic oil 24-0317WO01 radiator and the heating device 200. The fluid pipe section C is further provided with a second temperature sensor 400 at a position adjacent to the cooling liquid inflow chamber 6, which is used to detect the cooling liquid inflow temperature of the cooling liquid entering the cooling liquid channels of the hydraulic oil radiator.

[0043] The hydraulic oil heat recovery system may further include a controller (not shown). The controller is in signaling connection with the control valve 500 to send an opening or closing command to the control valve to open or close the control valve, so that the heating device and the hydraulic oil radiator are in fluid connection or disconnected from each other.

[0044] The controller is in signaling connection with the first temperature sensor 300 and the second temperature sensor 400. The controller can store a first preset value and a second preset value, which represent the preset temperature difference between the hydraulic oil inflow temperature and the cooling liquid inflow temperature. The first preset value is used to represent a preset temperature difference threshold for disconnecting the fluid communication between the heating device 200 and the hydraulic oil radiator 1, and the second preset value is used to represent a preset temperature difference threshold for establishing the fluid communication between the heating device 200 and the hydraulic oil radiator 1, wherein the first preset value is less than the second preset value. Specifically, after receiving signals from the first temperature sensor 300 and the second temperature sensor 400, the controller compares the actual temperature difference between the hydraulic oil inflow temperature and the cooling liquid inflow temperature with the first preset value. When the actual temperature difference decreases to the first preset value, the controller closes the control valve 500 and thereby disconnects the fluid communication between the heating device 200 and the hydraulic oil radiator, which means stopping the use of heat of the hydraulic oil radiator for heating. This is because when the actual temperature difference between the hydraulic oil inflow temperature and the 24-0317WO01 cooling liquid inflow temperature decreases to the first preset value, the hydraulic oil inflow temperature is very low, and there is not much heat available for recovery. If this part of heat is forcibly recovered, the oil temperature in the hydraulic system may be very low, which is not conducive to normal operation of the hydraulic system. When the actual temperature difference between the hydraulic oil inflow temperature and the cooling liquid inflow temperature rises to the second preset value, if there is a heating demand at this time, the controller will open the control valve 500 in response to the heating request, making the heating device 200 be in fluid communication with the hydraulic oil radiator. Thereby part of the heat of the hydraulic oil is recovered to heat the cab. For example, the first preset value is set to 5 DC and the second preset value is set to 10 DC.

[0045] The hydraulic oil heat recovery system further includes a pump 900 for pumping the cooling liquid to circulate between the hydraulic oil radiator and the heating device.

[0046] In addition, the hydraulic oil heat recovery system can also include a third temperature sensor 600 in signaling connection with the controller. The third temperature sensor 600 can be arranged on the pipe section B in communication with the hydraulic oil outflow chamber 3 to detect the hydraulic oil outflow temperature of the hydraulic oil flowing out of the hydraulic oil radiator 1. A first temperature limit and a second temperature limit can be set in the controller, and the first temperature limit is greater than the second temperature limit. The first temperature limit indicates a control limit based on the hydraulic oil outflow temperature when the control valve 500 is in the open state (i.e., part of the heat of the hydraulic oil of the hydraulic oil radiator is used for heating), and the second temperature limit indicates a control limit based on the hydraulic oil outflow temperature when the control valve 500 is in the closed state. For example, the first temperature limit is set to 60 DC and the second temperature limit is set to 46 DC. Specifically, after receiving a signal from the 24-0317WO01 third temperature sensor 600, the controller compares this signal with the first temperature limit or the second temperature limit in view of the open or closed state of the control valve 500. When the control valve 500 is in the open state, the controller sends a control command to increase the rotational speed of the fan 4 to the fan control device when the hydraulic oil outflow temperature measured by the third temperature sensor 600 reaches 60 DC. When the control valve 500 is in the closed state, the controller sends a control command to increase the rotational speed of the fan 4 to the fan control device when the hydraulic oil outflow temperature measured by the third temperature sensor 600 reaches 46 DC.

[0047] In the illustrated embodiment, the hydraulic oil heat recovery system further includes a PTC (positive temperature coefficient) heater 700 for auxiliary heating. The PTC heater is arranged in a cooling liquid branch connected in parallel with the branch where the cooling liquid channels of the hydraulic oil radiator 1 are located. The control valve 500 is arranged on the branch where the cooling liquid channels of the hydraulic oil radiator 1 are located. The fourth temperature sensor 800 is arranged on the upstream pipe section of the heating device 200 for detecting the temperature of the cooling liquid flowing into the heating device (when the PTC heater is turned off, the cooling liquid temperature measured by the fourth temperature sensor 800 can also be regarded as the outflow temperature of the cooling liquid flowing out of the hydraulic oil radiator 1). The controller is in signaling connection with the PTC heater 700. The controller is suitable for sending a start instruction or a power adjustment instruction to the PTC heater when the cooling liquid temperature measured by the fourth temperature sensor 800 does not reach the preset value during heating.

[0048] In the illustrated embodiment, the hydraulic oil radiator is shown to have a single-pass design. It will be appreciated that the hydraulic oil channels can be designed to have multiple passes from the hydraulic oil inflow chamber to the hydraulic oil outflow chamber. The division of the hydraulic oil channels into 24-0317WO01 the first sections and the second sections can be carried out along the extension direction of the hydraulic oil channels. Therefore, the positional relationship between the first heat dissipation core portion and the second heat dissipation core portion is not limited to the upper and lower relationship as shown.

[0049] The cooling liquid channel in the hydraulic oil radiator of the present disclosure is also not limited to the configuration shown. For example, it can be designed as a sleeve-shaped fluid channel constructed around the hydraulic oil channel.

[0050] The present disclosure also provides a construction machine comprising the above-mentioned hydraulic oil heat recovery system. The construction machine is, for example, an excavator, in particular a new energy excavator. By means of the hydraulic oil radiator and the hydraulic oil heat recovery system, the construction machine advantageously integrates hydraulic oil cooling and air conditioning heating, which not only reduces the load of the hydraulic oil radiator, but also saves energy and improves comfort in the cab by combinedly using PTC heating.

[0051] Industrial Applicability

[0052] The hydraulic oil radiator according to the present disclosure is particularly suitable for a hydraulic oil heat recovery system of a construction machine with a hydraulic system. However, it will be appreciated that the hydraulic oil radiator according to the present disclosure can also be used for other equipment with a hydraulic system that requires heat collection and heat utilization.

[0053] Now the embodiments shown in Figs. 1 to 3 are used as an example to describe the hydraulic oil radiator with a composite configuration according to the present disclosure. First, there are provided a hydraulic oil inflow chamber, a hydraulic oil outflow chamber, and tubes vertically arranged between the two chambers for defining hydraulic oil channels. The tubes are arranged in parallel at intervals along the X direction. The tubes can be 24-0317WO01 constructed by pairs of plates with closed edge sides, that is, formed as flat tubes. The cross-sectional shape of the flat tube has a length extending in the Y direction and a width extending in the X direction. In the region corresponding to the upstream first sections 101 of the hydraulic oil channels, seals are arranged on the front and rear sides between adjacent plate pairs to form cooling liquid channels. A cooling liquid inflow box defining the cooling liquid inflow chamber is arranged at the inflow ends of the cooling liquid channels. A cooling liquid outflow box defining the cooling liquid outflow chamber is arranged at the outflow ends of the cooling liquid channels. Thus, a first heat dissipation core portion 101c of the hydraulic oil radiator is formed. In the region corresponding to the downstream second sections 102 of the hydraulic oil channels, radiating fins are provided between adjacent plate pairs. Thus, a second heat dissipation core portion 102c of the hydraulic oil radiator is formed. As can be seen, the hydraulic oil radiator according to the present disclosure has a simple and compact structure, a simple process, and a low manufacturing cost. The existing plate-fin type hydraulic oil radiator can be modified easily by arranging fins of different orientations between adjacent plate pairs in the upstream section and adding seals, a cooling liquid inflow box and a cooling liquid outflow box. Therefore, the modification cost is very low.

[0054] Now the embodiments illustrated in Figs. 1 to 3 are used as an example to briefly describe the working process of the hydraulic oil radiator 1 and the hydraulic oil heat recovery system.

[0055] When the hydraulic system is working, the hydraulic oil flows through the hydraulic oil radiator 1 from top to bottom. In response to the heating request, the controller first determines whether the hydraulic oil heat recovery heating mode is available. When the temperature difference between the first temperature sensor 300 and the second temperature sensor 400 rises to the second preset value (e.g., 10°C), the controller opens the control valve 500. Under the driving action of the pump 900, the cooling liquid circulates through the cooling 24-0317WO01 liquid channels of the hydraulic oil radiator 1, thereby exchanging heat with the hydraulic oil flowing through the first heat dissipation core portion 101c and taking away part of the heat of the hydraulic oil. The heated cooling liquid enters the heating device 200 for heating. That is, the hydraulic oil heat recovery heating mode is enabled for heating. When the hydraulic oil heat recovery heating mode is still insufficient to meet the heating demand, the PTC heating mode can be enabled to assist heating.

[0056] When the load of the hydraulic system decreases and the temperature of the hydraulic oil entering the hydraulic oil radiator decreases, the temperature difference between the first temperature sensor 300 and the second temperature sensor 400 will decrease. When the temperature difference between the first temperature sensor 300 and the second temperature sensor 400 drops to the first preset value (e.g., 5°C), the controller closes the control valve 500 and disconnects the fluid connection between the heating device 200 and the hydraulic oil radiator 1. At this time, it means that part of the heat of the hydraulic oil cannot be recovered (because its recovery efficiency is extremely low), and only the PTC heating mode can be enabled for heating.

[0057] Since the hydraulic oil flowing out of the hydraulic oil radiator needs to be returned to the hydraulic system for recycling, the hydraulic oil outflow temperature needs to be monitored. The controller first obtains the heating mode information of the hydraulic oil heat recovery system. When the system uses the hydraulic oil heat recovery heating mode for heating, it determines whether the hydraulic oil outflow temperature measured by the third temperature sensor 600 reaches the first temperature limit (e.g., 60°C). Once the hydraulic oil outflow temperature reaches the first temperature limit (indicating that the hydraulic oil flowing out of the hydraulic oil radiator has the risk of overheating), the controller sends a control command to the fan control device to increase the rotation speed of the fan. Thus, the second heat dissipation core portion 102c is used to significantly cool the hydraulic oil or suppress the 24-0317WO01 increase in the hydraulic oil outflow temperature. When the system only uses the PTC heating mode for heating or there is no heating demand, it determines whether the hydraulic oil outflow temperature measured by the third temperature sensor 600 reaches the second temperature limit (for example, 46°C). Once the hydraulic oil outflow temperature reaches the second temperature limit (which also indicates that the hydraulic oil flowing out of the hydraulic oil radiator has a risk of overheating), the controller sends a control command to the fan control device to increase the rotation speed of the fan.

[0058] As described above, the hydraulic oil radiator 1 according to the present disclosure includes a first heat dissipation core portion having a hydraulic oil-cooling liquid counter-current heat exchange configuration and a second heat dissipation core portion having a hydraulic oil-air crossflow heat exchange configuration, which effectively recycles part of the heat of the hydraulic oil, thereby reducing the load and improving the overall compactness of the hydraulic oil radiator, and avoiding such problems as difficult arrangement and high control cost resulting from too many circuits existing in the prior art. As for the application of the hydraulic oil radiator 1 in the hydraulic oil heat recovery system, optionally the hydraulic oil radiator 1 can be used with the PTC heater 700 to achieve the purpose of energy saving advantageously, which is particularly suitable for the integration of hydraulic oil heat dissipation and air conditioning heating in the hydraulic system of a new energy hydraulic excavator.

[0059] Those skilled in the art can make various modifications and variations to the embodiments disclosed herein without departing from the scope or spirit of the present disclosure. Other embodiments of the present disclosure will be apparent to those skilled in the art according to the practice of the disclosure disclosed in this specification. This specification and the examples disclosed herein are considered to be illustrative only, and the true scope of the present disclosure is determined by the appended claims and their equivalents.

Claims

24-0317WO01Claims1. A hydraulic oil radiator for a construction machine, comprising: a plurality of hydraulic oil channels arranged in parallel at intervals, and a hydraulic oil inflow chamber and a hydraulic oil outflow chamber arranged at both ends of the hydraulic oil channels and communicated with them, characterized in that the hydraulic oil channels each comprise a first section located upstream and a second section located downstream along a flow direction of the hydraulic oil; in a region corresponding to the first sections, cooling liquid channels in which cooling liquid flows are arranged outside the hydraulic oil channels, and in the first sections, the hydraulic oil exchanges heat with the cooling liquid; in a region corresponding to the second sections, radiating fins that define cooling airflow channels are arranged outside the hydraulic oil channels, and in the second sections, the hydraulic oil exchanges heat with cooling airflow.

2. The hydraulic oil radiator according to claim 1, characterized in that at two ends of the cooling liquid channels, a cooling liquid inflow chamber and a cooling liquid outflow chamber are provided, which are communicated with the cooling liquid channels, wherein the cooling liquid inflow chamber is close to downstream ends of the first sections of the hydraulic oil channels, and the cooling liquid outflow chamber is close to upstream ends of the first sections of the hydraulic oil channels.

3. The hydraulic oil radiator according to claim 2, characterized in that the cooling liquid inflow chamber is arranged on a first face side of the hydraulic oil radiator, the cooling liquid outflow chamber is arranged on a second face side of the hydraulic oil radiator, and the first face side and the second face side are opposite to each other in a thickness direction of the24-0317WO01 hydraulic oil radiator that is perpendicular to an extension direction of the hydraulic oil channels and a parallel arrangement direction of the hydraulic oil channels.

4. The hydraulic oil radiator according to claim 3, characterized in that a fan is arranged on the first face side of the hydraulic oil radiator in the region corresponding to the second sections of the hydraulic oil channels, so as to force the airflow to pass through cooling airflow channels and form a cross flow with a hydraulic oil flow in the second sections of the hydraulic oil channels.

5. The hydraulic oil radiator according to claim 3 or 4, characterized in that the hydraulic oil inflow chamber is located at an upper end of the hydraulic oil radiator, the hydraulic oil outflow chamber is located at a lower end of the hydraulic oil radiator, an outer wall of the hydraulic oil inflow chamber located on the first face side of the hydraulic oil radiator is provided with an oil inlet, and an outer wall of the hydraulic oil outflow chamber located on the first face side of the hydraulic oil radiator is provided with an oil outlet.

6. A hydraulic oil heat recovery system for a construction machine, comprising a hydraulic oil radiator according to any one of claims 1 to 5 and a heating device for heating a cab of the construction machine, wherein the heating device is in fluid connection with the hydraulic oil radiator, so that a heatcarrying medium flowing through the heating device flows into the cooling liquid channels of the hydraulic oil radiator as the cooling liquid, and the cooling liquid flowing out of the cooling liquid channels of the hydraulic oil radiator flows into the heating device as the heat-carrying medium.24-0317WO017. The hydraulic oil heat recovery system according to claim6, characterized in that a control valve is provided in a pipe section located upstream of the hydraulic oil radiator and downstream of the heating device, wherein the control valve is signal-connected to a controller of the hydraulic oil heat recovery system and is opened or closed according to an opening or closing instruction from the controller, thus achieving fluid communication or disconnection between the heating device and the hydraulic oil radiator.

8. The hydraulic oil heat recovery system according to claim7, characterized by comprising: a first temperature sensor for detecting a hydraulic oil inflow temperature of the hydraulic oil entering the hydraulic oil radiator and a second temperature sensor for detecting a cooling liquid inflow temperature of the cooling liquid entering the cooling liquid channels of the hydraulic oil radiator, the controller being signal-connected to the first and second temperature sensors, and being adapted to close the control valve to disconnect the fluid communication between the heating device and the hydraulic oil radiator when a temperature difference between the hydraulic oil inflow temperature and the cooling liquid inflow temperature drops to a first preset value, and to open the control valve in response to a heating request to enable fluid communication between the heating device and the hydraulic oil radiator when the temperature difference between the hydraulic oil inflow temperature and the cooling liquid inflow temperature rises to a second preset value, wherein the first preset value is less than the second preset value.

9. The hydraulic oil heat recovery system according to claim 7 or 8, characterized by comprising a third temperature sensor for detecting a hydraulic oil outflow temperature of the hydraulic oil radiator, the controller being adapted to increase a rotation speed of the fan for forcing the cooling airflow to pass through the cooling airflow channels in response to the hydraulic-22-24-0317WO01 oil outflow temperature measured by the third temperature sensor reaching a first temperature limit when the control valve is in an open state, and to increase the rotation speed of the fan in response to the hydraulic oil outflow temperature measured by the third temperature sensor reaching a second temperature limit when the control valve is in a closed state, wherein the first temperature limit is greater than the second temperature limit.

10. A construction machine, characterized by comprising a hydraulic oil heat recovery system according to any one of claims 6 to 9.

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