Hydraulic oil waste heat recovery system and construction machinery

Abstract

The present invention provides a hydraulic oil waste heat recovery system and engineering machinery, and relates to the technical field of engineering machinery. The hydraulic oil waste heat recovery system includes a hydraulic oil tank, a working device, a heat exchanger and a heating device. The hydraulic oil tank is connected to the working device, and a pump is arranged between the hydraulic oil tank and the working device so that the hydraulic oil tank can transport hydraulic oil to the working device. The working device and the heating device are both connected to the heat exchanger. The heat exchanger is used to exchange heat between the hydraulic oil passing through the working device and the heat-carrying medium flowing through the heating device, so as to transfer the waste heat of the hydraulic oil to the heat-carrying medium. The engineering machinery includes a hydraulic oil waste heat recovery system. The hydraulic oil waste heat recovery system can reduce the energy consumption of the pump when recovering the waste heat of the hydraulic oil, which is beneficial to energy saving.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering machinery, and in particular to a hydraulic oil waste heat recovery system and engineering machinery. Background Art

[0002] Hydraulic oil is used in construction machinery such as excavators to power the working device so that the working device can work normally. After the hydraulic oil flows out of the working device, it carries a lot of heat. Before the hydraulic oil is returned to the hydraulic oil tank, it is usually necessary to use a hydraulic oil radiator to dissipate the heat of the hydraulic oil, and this part of the heat is lost.

[0003] In the prior art, the heat carried by the hydraulic oil flowing out of the working device can be used to assist the air conditioner in heating the operating room, so as to recycle the heat of the hydraulic oil. However, since the hydraulic oil needs to be directly sent to the evaporator coil for heat transfer, the transportation distance is long, the hydraulic pipeline is long, and the energy consumption of the pump is large, which is not conducive to energy saving. Summary of the invention

[0004] The purpose of the present invention includes providing a hydraulic oil waste heat recovery system and engineering machinery, which can reduce pump energy consumption when recovering hydraulic oil waste heat, thereby facilitating energy saving.

[0005] The embodiments of the present invention can be implemented as follows:

[0006] In a first aspect, an embodiment of the present invention provides a hydraulic oil waste heat recovery system, which includes a hydraulic oil tank, a working device, a heat exchanger and a heating device. The hydraulic oil tank is connected to the working device, and a pump is arranged between the hydraulic oil tank and the working device to enable the hydraulic oil tank to transport hydraulic oil to the working device. The working device and the heating device are both connected to the heat exchanger. The heat exchanger is used to exchange heat between the hydraulic oil passing through the working device and the heat carrier medium flowing through the heating device, so as to transfer the waste heat of the hydraulic oil to the heat carrier medium.

[0007] In an optional embodiment, it includes a hydraulic oil radiator and a valve, the valve has a first interface, a second interface and a third interface, the first interface can be selectively connected to the second interface or the third interface, the first interface is connected to the working device, the second interface is connected to the hydraulic oil radiator, the hydraulic oil radiator is connected to the hydraulic oil tank, and the third interface is connected to the heat exchanger.

[0008] In an optional embodiment, the valve is a three-way solenoid valve.

[0009] In an alternative embodiment, the heat exchanger comprises a plate heat exchanger.

[0010] In an optional embodiment, the heat exchanger has a first inlet, a first outlet, a second inlet and a second outlet, the first inlet is connected to the first outlet, the second inlet is connected to the second outlet, the working device is connected to the first inlet, the hydraulic oil tank is connected to the first outlet, the heating device is connected to the second inlet and the second outlet, and a one-way valve is arranged between the first outlet and the hydraulic oil tank.

[0011] In an optional embodiment, the pump includes a plunger pump connected between the hydraulic oil tank and the working device.

[0012] In an optional embodiment, the heating device includes a heater core, which is connected to the heat exchanger and is used to allow a heat carrier medium to flow for heating.

[0013] In an optional embodiment, the heating device includes a storage box, the storage box is connected to the heat exchanger, the storage box is used to store the heat carrier medium, and the heater core is connected to the storage box.

[0014] In an alternative embodiment, the heat transfer medium comprises water.

[0015] In a second aspect, an embodiment of the present invention provides a construction machinery comprising a hydraulic oil waste heat recovery system according to any one of the aforementioned embodiments.

[0016] The beneficial effects of the embodiments of the present invention include:

[0017] The hydraulic oil waste heat recovery system adds a heat exchanger, so that the hydraulic oil flowing through the working device can first exchange heat with the heating device in the heat exchanger, transfer the waste heat of the hydraulic oil to the heat-carrying medium of the heating device, and then the heat-carrying medium releases heat at the heating device to heat the user, effectively recovering the waste heat of the hydraulic oil. In the prior art, the hydraulic oil is directly sent to the evaporator coil. Since the hydraulic oil pipeline is generally thin to ensure the oil pressure of the hydraulic oil, the energy consumption requirement of the pump is high. Compared with the prior art, the hydraulic oil waste heat recovery system can return the hydraulic oil to the hydraulic oil tank after sending it to the heat exchanger, and there is no need to set up a long hydraulic oil pipeline. Therefore, the energy consumption of the pump of the hydraulic oil waste heat recovery system is small, which is beneficial to energy saving and reducing the energy consumption of construction machinery. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 Schematic diagram of the structure of the hydraulic oil waste heat recovery system in an embodiment of the present invention.

[0020] Icons: 100-hydraulic oil waste heat recovery system; 110-hydraulic oil tank; 120-working device; 130-pump; 140-heat exchanger; 141-first inlet; 142-first outlet; 143-second inlet; 144-second outlet; 146-check valve; 150-heating device; 152-heater core; 154-storage tank; 156-water pump; 160-hydraulic oil radiator; 170-valve; 171-first interface; 172-second interface; 173-third interface; 190-air conditioning unit; 191-compressor; 192-condenser; 193-evaporator; 194-blower. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0022] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0024] In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear to indicate an orientation or position relationship, they are based on the orientation or position relationship shown in the accompanying drawings, or are the orientation or position relationship in which the product of the invention is usually placed when used. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0025] In addition, the terms “first”, “second”, etc., if used, are merely used to distinguish between the descriptions and should not be understood as indicating or implying relative importance.

[0026] It should be noted that, in the absence of conflict, the features in the embodiments of the present invention may be combined with each other.

[0027] Please refer to Figure 1This embodiment provides a hydraulic oil waste heat recovery system 100, including a hydraulic oil tank 110, a working device 120, a heat exchanger 140 and a heating device 150. The hydraulic oil tank 110 is connected to the working device 120, and a pump 130 is provided between the hydraulic oil tank 110 and the working device 120 so that the hydraulic oil tank 110 can deliver hydraulic oil to the working device 120. The working device 120 and the heating device 150 are both connected to the heat exchanger 140, and the heat exchanger 140 is used to exchange heat between the hydraulic oil passing through the working device 120 and the heat carrier medium flowing through the heating device 150, so as to transfer the waste heat of the hydraulic oil to the heat carrier medium.

[0028] The hydraulic oil waste heat recovery system 100 can be applied to various engineering machinery such as excavators, cranes, etc. In this embodiment, the excavator is mainly used as an example for explanation.

[0029] For an excavator, the working device 120 is a device that directly completes the excavation task, including multiple parts such as a boom, a dipper arm, and a bucket. The raising and lowering of the boom, the extension and retraction of the dipper arm, and the rotation of the bucket are all driven by hydraulic oil. When the excavator is working, the pump 130 delivers the hydraulic oil in the hydraulic oil tank 110 to the working device 120. After the hydraulic oil is energized in the working device 120, it will carry residual heat.

[0030] In this embodiment, the pump 130 includes a plunger pump 130, and the plunger pump 130 is connected between the hydraulic oil tank 110 and the working device 120. In other embodiments, the pump 130 may also be a gear pump 130, a vane pump 130 or other types of pumps 130.

[0031] The hydraulic oil waste heat recovery system 100 further includes a valve 170. Specifically, the valve 170 has a first interface 171, a second interface 172, and a third interface 173. The first interface 171 is connected to the working device 120, and the hydraulic oil flowing through the working device 120 enters the valve 170 from the first interface 171. The first interface 171 can be selectively connected to the second interface 172 or the third interface 173, so that the hydraulic oil entering the valve 170 from the first interface 171 can selectively flow out from one of the second interface 172 and the third interface 173.

[0032] The hydraulic oil waste heat recovery system 100 also includes a hydraulic oil radiator 160. The second interface 172 is connected to the hydraulic oil radiator 160. A fan is provided in the hydraulic oil radiator 160. After the hydraulic oil enters the hydraulic oil radiator 160, it can exchange heat with the air under the action of the fan, thereby realizing the heat dissipation of the hydraulic oil and reducing the oil temperature. The hydraulic oil radiator 160 is connected to the hydraulic oil tank 110. The cooled hydraulic oil finally returns to the hydraulic oil tank 110 to complete the hydraulic oil circulation.

[0033] The third interface 173 is connected to the heat exchanger 140, so that the hydraulic oil can enter the heat exchanger 140 after flowing out of the third interface 173 to exchange heat with the heat carrier medium in the heat exchanger 140, thereby transferring the waste heat to the heat carrier medium and finally being transferred to the heating device 150 for heating.

[0034] In this embodiment, the valve 170 is a three-way solenoid valve. The three-way solenoid valve is electrically connected to the controller of the excavator to facilitate the switching of the flow path. Usually in summer, the heating device 150 is not needed to work. At this time, the first interface 171 of the three-way solenoid valve can be controlled to be connected with the second interface 172, and the third interface 173 can be closed. The hydraulic oil flowing through the valve 170 enters the hydraulic oil radiator 160 for heat dissipation, and returns to the hydraulic oil tank 110 after cooling. In winter, the heating device 150 needs to be turned on to heat the cab of the excavator. At this time, the first interface 171 of the three-way solenoid valve can be controlled to be connected with the third interface 173, and the second interface 172 can be closed. The hydraulic oil flowing through the valve 170 enters the heat exchanger 140 to exchange heat with the heat carrier medium, thereby transferring the waste heat of the hydraulic oil to the heat carrier medium, and finally used for heating.

[0035] In other embodiments, the valve 170 may not be a three-way solenoid valve, but may be a four-way valve 170 or a five-way valve 170 . It only needs to have a first interface 171 , a second interface 172 , and a third interface 173 to achieve the required functions.

[0036] The heat exchanger 140 has a first inlet 141, a first outlet 142, a second inlet 143, and a second outlet 144. The first inlet 141 is connected to the first outlet 142, and the second inlet 143 is connected to the second outlet 144. The working device 120 is connected to the first inlet 141, the hydraulic oil tank 110 is connected to the first outlet 142, and the heating device 150 is connected to the second inlet 143 and the second outlet 144.

[0037] In this embodiment, the third interface 173 of the valve 170 is connected to the first inlet 141. The hydraulic oil with residual heat can flow out of the third interface 173 and enter the heat exchanger 140 through the first inlet 141, and then flow out of the heat exchanger 140 through the first outlet 142. In order to ensure the oil pressure of the hydraulic oil, a high-pressure hose must be used to connect between the first inlet 141 and the third interface 173, and between the first outlet 142 and the hydraulic oil tank 110. However, the diameter of the high-pressure hose is relatively thin, and certain energy consumption requirements are imposed on the pump 130.

[0038] In this embodiment, to prevent the hydraulic oil from flowing back, a one-way valve 146 is provided between the first outlet 142 and the hydraulic oil tank 110. The one-way valve 146 only allows the hydraulic oil to flow from the heat exchanger 140 to the hydraulic oil tank 110, and does not allow the hydraulic oil to flow from the hydraulic oil tank 110 to the heat exchanger 140. In other embodiments, the one-way valve 146 may also be provided between the first inlet 141 and the three-way solenoid valve to prevent the hydraulic oil from flowing back from the heat exchanger 140 to the three-way solenoid valve.

[0039] The heating device 150 is connected to the second inlet 143 and the second outlet 144. The heat medium with a lower temperature flows out of the heating device 150 and enters the heat exchanger 140 through the second inlet 143, exchanges heat with the hydraulic oil, and then flows back to the heating device 150 from the second outlet 144. The hydraulic oil and the heat medium can effectively exchange heat in the heat exchanger 140, and the residual heat of the hydraulic oil is transferred to the heat medium.

[0040] The heating device 150 includes a heater core 152, which is connected to the heat exchanger 140 and is used to flow a heat carrier medium for heating. Specifically, the heater core 152 is a part of an air conditioning unit 190 in the excavator. The air conditioning unit 190 also includes a compressor 191, a condenser 192 and an evaporator 193 connected in sequence, the evaporator 193 is connected to the compressor 191, the compressor 191, the condenser 192 and the evaporator 193 are used for cooling, and the evaporator 193 can provide cooling to the cab in summer.

[0041] The heater core 152 is generally a tubular structure, and a cavity is provided inside the heater core for the heat medium to flow. In this embodiment, the heat medium is water. In other embodiments, the heat medium may be other liquid media, such as water containing a substance with a large specific heat capacity, as long as it can meet the heat exchange requirements.

[0042] The heating device 150 further includes a storage box 154, which is connected to the heat exchanger 140. The storage box 154 is used to store a heat carrier medium, and the heater core 152 is connected to the storage box 154. Specifically, the inlet of the storage box 154 is connected to the second outlet 144 of the heat exchanger 140, and the heat carrier medium carrying the residual heat of the hydraulic oil flows out of the heat exchanger 140 and enters the storage box 154. The outlet of the storage box 154 is connected to one end of the heater core 152, and the other end of the heater core 152 is connected to the second inlet 143 of the heat exchanger 140. The heat carrier medium carrying the residual heat of the hydraulic oil dissipates heat in the heater core 152, and a blower 194 (the evaporator 193 and the heater core 152 share the blower 194) is provided near the heater core 152 in the air conditioning unit, so that warm air can be blown into the cab to achieve heating. The heat-carrying medium carrying the residual heat of the hydraulic oil can be mixed more evenly when entering the storage tank 154, so that the temperature of the heat-carrying medium is uniform and the flow rate is more stable.

[0043] In addition, a heat preservation layer is provided outside the storage box 154 to improve the heat preservation performance of the storage box 154. An exhaust hole is provided on the storage box 154 to allow excess gas in the box to escape. A water pump 156 is also connected between the storage box 154 and the warm air core 152 to provide water flow power.

[0044] The second outlet 144 and the storage box 154, and the second inlet 143 and the warm air core 152 are connected by an insulating hose. The diameter of the insulating hose is much larger than that of the high-pressure hose. The pipe resistance in the insulating hose is small, and the energy consumption requirements for the pump 130 and the water pump 156 are low, which is conducive to energy saving.

[0045] In this embodiment, the heat exchanger 140 adopts a plate heat exchanger. The plate heat exchanger is a high-efficiency heat exchanger formed by stacking a series of metal sheets with a certain corrugated shape. Thin rectangular channels are formed between various plates, and heat exchange is carried out through the plates. It has the characteristics of high heat exchange efficiency, small heat loss, compact and light structure, small footprint, wide application, and long service life. Under the same pressure loss, its heat transfer coefficient is 3-5 times higher than that of the tube heat exchanger, the footprint is one-third of the tube heat exchanger 140, and the heat recovery rate can be as high as 90% or more. In other embodiments, other types of heat exchangers such as shell and tube heat exchanger 140 can also be used.

[0046] Thus, the hydraulic oil waste heat recovery system 100 can exchange waste heat carried in the hydraulic oil passing through the working device 120 with the heat carrier medium in the heating device 150 in the heat exchanger 140, thereby recovering the waste heat of the hydraulic oil for heating, which is beneficial to energy saving.

[0047] In this embodiment, the hydraulic oil waste heat recovery system 100 connects the heat exchanger 140 and the hydraulic oil radiator 160 in parallel by means of a three-way solenoid valve, so that the original hydraulic system can selectively switch the destination of the hydraulic oil as needed. It can be understood that in other embodiments, the hydraulic oil waste heat recovery system 100 can also be set up separately to make it independent of the original hydraulic oil circulation system, and in this case, the switching valve 170 such as the three-way solenoid valve may no longer be set up.

[0048] An embodiment of the present invention provides a construction machinery, including the hydraulic oil waste heat recovery system 100 described above.

[0049] The working principle and process of the hydraulic oil waste heat recovery system 100 are as follows:

[0050] In winter, the cab needs to be heated. The control valve 170 is switched to a state where the first interface 171 is connected to the third interface 173 and the second interface 172 is closed, so that the hydraulic oil flowing through the working device 120 enters the heat exchanger 140. The hydraulic oil carries the residual heat and exchanges heat with the heat-carrying medium entering the heat exchanger 140, transferring the residual heat to the heat-carrying medium. The heat-carrying medium obtains the residual heat of the hydraulic oil in the heat exchanger 140 and flows out, and then enters the heater core 152 through the storage box 154. The heater core 152 can exchange heat with the air in the cab for heating. After the heated heat-carrying medium flows out from the heater core 152, it returns to the heat exchanger 140 through the second inlet 143 and exchanges heat with the hydraulic oil again, forming a cycle. In this way, the residual heat of the hydraulic oil is recovered for heating.

[0051] In summer, there is no need to heat the cab, and the control valve 170 is switched to a state where the first interface 171 is connected to the second interface 172 and the third interface 173 is closed. The hydraulic oil carrying residual heat enters the hydraulic oil radiator 160 for heat dissipation, and returns to the hydraulic oil tank 110 after cooling.

[0052] In summary, the hydraulic oil waste heat recovery system 100 can recover the waste heat of the hydraulic oil for heating when heating is needed. By setting the heat exchanger 140, the waste heat of the hydraulic oil is transferred to the heat carrier medium for heating. Since the heat exchanger 140 is provided, a conventional heat-insulating hose can be used between it and the heating device 150, instead of using a thinner high-pressure hose like the hydraulic oil circuit. The energy consumption requirements for the pump 130 and the water pump 156 are low, which is beneficial to energy saving. The pump 130 is connected to the engine of the excavator, which is beneficial to extending the life of the engine.

[0053] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A hydraulic oil waste heat recovery system, characterized in that: The invention comprises a hydraulic oil tank, a working device, a heat exchanger and a heating device, wherein the hydraulic oil tank is connected to the working device, and a pump is arranged between the hydraulic oil tank and the working device so that the hydraulic oil tank can deliver hydraulic oil to the working device, the working device and the heating device are both connected to the heat exchanger, and the heat exchanger and the heating device are connected via a heat-insulating hose, and the heat exchanger is used to exchange heat between the hydraulic oil passing through the working device and the heat-carrying medium passing through the heating device, so as to transfer the residual heat of the hydraulic oil to the heat-carrying medium; The hydraulic oil waste heat recovery system also includes a valve and a hydraulic oil radiator, the valve has a first interface, a second interface and a third interface, the first interface can be selectively connected to the second interface or the third interface, the first interface is connected to the working device, the second interface is connected to the hydraulic oil radiator, the hydraulic oil radiator is connected to the hydraulic oil tank, and the third interface is connected to the heat exchanger; Among them, when the cab is heated, the first interface of the valve is connected to the third interface, and the second interface is in a closed state; when the cab is not heated, the first interface of the valve is connected to the second interface, and the third interface is in a closed state.

2. The hydraulic oil waste heat recovery system according to claim 1, characterized in that: The valve is a three-way solenoid valve.

3. The hydraulic oil waste heat recovery system according to claim 1, characterized in that: The heat exchanger comprises a plate heat exchanger.

4. The hydraulic oil waste heat recovery system according to claim 1, characterized in that: The heat exchanger has a first inlet, a first outlet, a second inlet and a second outlet, the first inlet is connected to the first outlet, the second inlet is connected to the second outlet, the working device is connected to the first inlet, the hydraulic oil tank is connected to the first outlet, the heating device is connected to the second inlet and the second outlet, and a one-way valve is arranged between the first outlet and the hydraulic oil tank.

5. The hydraulic oil waste heat recovery system according to claim 1, characterized in that: The pump comprises a plunger pump connected between the hydraulic oil tank and the working device.

6. The hydraulic oil waste heat recovery system according to claim 1, characterized in that: The heating device comprises a heater core, the heater core is connected to the heat exchanger, and the heater core is used for allowing the heat carrier medium to flow to provide heat.

7. The hydraulic oil waste heat recovery system according to claim 6, characterized in that: The heating device comprises a storage box, the storage box is connected to the heat exchanger, the storage box is used to store the heat carrier medium, and the warm air core is connected to the storage box.

8. The hydraulic oil waste heat recovery system according to claim 1, characterized in that: The heat carrier medium includes water.

9. An engineering machine, characterized in that: A hydraulic oil waste heat recovery system comprising any one of claims 1-8.

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