KR101911139B1 - Fuel efficiency improvement system by recovering waste heat of construction machinery - Google Patents

Abstract

The present invention provides a construction machine having a hydraulic system, a cooling system, and an engine, comprising: a first heat exchanger for exchanging heat between the hydraulic fluid and the working fluid; And a second heat exchanger that exchanges heat between the working fluid from the first heat exchanger and the cooling water in the cooling system and circulates the working fluid to heat exchange with the hydraulic system, the cooling system, An organic Rankine cycle; A radiator provided at one side of the engine and supplied with cooling water of the cooling system; And the cooling water of the cooling system from the engine can be selectively distributed to the radiator or the second heat exchanger. The system for improving fuel economy through the recovery of the piping of the construction machine according to the present invention can convert the waste heat of the operating oil, the cooling water, and the waste gas to a driving source capable of driving the construction machine . As a result, the fuel consumption of the construction machine can be reduced.

Description

FIELD EFFICIENCY IMPROVEMENT SYSTEM RECOVERING WASTE HEAT OF CONSTRUCTION MACHINERY BACKGROUND OF THE INVENTION [0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a construction machine, and more particularly, to a construction machine having a hydraulic system, which recovers thermal energy from an abandoned operating oil, cooling water or waste gas, The present invention relates to a system for improving the fuel economy by collecting the cooling water flow path of the radiator variously or omitting the radiator and recovering the heat of the construction machine.

Generally, a diesel engine of a construction machine generates a lot of heat during operation. At this time, some of the generated heat energy is reduced to mechanical energy, but a lot of waste heat energy that can not be reduced to mechanical energy is generated.

Accordingly, in recent years, research and development have been actively conducted on technologies for recovering waste energy such as waste heat, which is discharged from exhaust gas, operating oil, cooling water, etc. of an engine, and regenerating the waste energy as electric energy or mechanical energy.

The main reason for the interest in such waste energy recovery technology is that the heat energy that is abandoned even in a high efficiency engine is still considerable, and that the development of combustion and engine peripherals for fuel efficiency has reached a certain limit Because.

In particular, in the case of a construction machine equipped with a hydraulic system using hydraulic oil, the temperature of the hydraulic oil is low, but a large amount of heat is included.

On the other hand, a power generation apparatus using an Organic Rankine Cycle (ORC) has been extensively tried as a method of recovering heat energy of middle and low temperature discharged from the exhaust gas of a diesel engine of a construction machine. A typical Rankine cycle is to rotate a turbine using high pressure steam while passing through an evaporator, and converting the generated thrust into electric energy. In addition, many generators using an organic Rankine cycle have been attempted. Unlike ordinary Rankine cycles, water is not used as an operating fluid. Instead of using water as an operating fluid, an organism such as ammonia or alcohol (or an organic mixture ) Is used.

In recent years, major advanced countries and manufacturers have been developing technologies to utilize the waste energy of diesel engines using organic Rankine cycle. However, currently developed technologies do not recover much heat from waste energy such as exhaust gas or cooling water of diesel engine There is a problem in that the electric power that can be utilized for the development of the diesel engine is not large.

The applicant of the present invention has proposed the present invention in order to solve the above-mentioned problems. As a prior art document related thereto, Korean Patent Registration No. 10-1290289 entitled " Temperature Induced Organic Rankine Cycle Generating Device for Ship, Posted on: July 22, 2013).

SUMMARY OF THE INVENTION An object of the present invention is to provide a method and apparatus for recovering thermal energy of operating oil, cooling water, and waste gas discarded in a construction machine having a hydraulic system and recovering the heat energy of a construction machine capable of converting it into electric power or mechanical energy that can be used as a driving source of a construction machine Fuel efficiency improvement system.

It is another object of the present invention to provide a system for improving fuel economy through the recovery of heat from a construction machine that can increase the amount of heat recovered from thermal energy of operating oil, cooling water, and waste gas discarded in a construction machine by utilizing a radiator as a heat exchanger will be.

It is another object of the present invention to provide a system for improving the fuel economy by eliminating the radiator of the cooling system for cooling the engine of the construction machine or replacing the role of the radiator with the heat exchanger of the organic Rankine cycle.

Further, it is an object of the present invention to provide a system for improving fuel economy through regeneration of a construction machine capable of regulating a circulation path of a working fluid by a state change, a temperature or a heat quantity of a working fluid of an organic Rankine cycle.

The problems to be solved by the present invention are not limited to the above-mentioned problems, and other matters not mentioned can be clearly understood by those skilled in the art from the following description.

According to the present invention, there is provided a construction machine comprising a hydraulic system, a cooling system and an engine, comprising: a first heat exchanger for exchanging heat between the hydraulic fluid of the hydraulic system and the working fluid; An organic Rankine cycle for circulating the working fluid to heat exchange with the hydraulic system, the cooling system and the waste heat or waste energy of the engine in order, the second Rankine cycle including heat exchange with the working fluid and the cooling water of the cooling system; A radiator provided at one side of the engine and supplied with cooling water of the cooling system; And the cooling water of the cooling system from the engine can be selectively distributed to the radiator or the second heat exchanger.

The cooling system may further include a cooling water distributing valve for selectively distributing cooling water of the cooling system from the engine to the radiator or the second heat exchanger.

The cooling water distributing valve may operate such that the cooling water from the engine flows into the radiator after passing through the second heat exchanger, or the cooling water from the engine flows directly into the radiator.

According to another embodiment of the present invention, there is provided a construction machine having a hydraulic system, a cooling system, and an engine, comprising: a first heat exchanger for exchanging heat between the hydraulic fluid of the hydraulic system and the working fluid; An organic Rankine cycle for circulating the working fluid to heat exchange with the hydraulic system, the cooling system and the waste heat or waste energy of the engine in order, comprising a second heat exchanger for exchanging the working fluid with the cooling water of the cooling system; A radiator provided at one side of the engine and supplied with cooling water of the cooling system; And the radiator may be connected in series to a cooling water passage of the cooling system connecting the engine and the second heat exchanger.

The cooling water flow path of the cooling system connecting the engine, the second heat exchanger, and the radiator may form a closed circulation flow path.

According to another embodiment of the present invention, there is provided a construction machine including a hydraulic system, a cooling system, and an engine, the construction machine comprising: a first heat exchanger for exchanging heat between the hydraulic fluid of the hydraulic system and the working fluid; And a second heat exchanger for exchanging heat between the working fluid from the cooling system and the cooling water of the cooling system, the system comprising an organic Rankine cycle for circulating the working fluid to heat exchange with the hydraulic system, the cooling system and the waste heat or waste energy of the engine And the cooling water flow path of the cooling system may serve as a radiator that connects the engine and the second heat exchanger in series to cool the engine by the second heat exchanger.

The cooling water flow path of the cooling system connecting the engine and the second heat exchanger may form a closed circulation flow path.

According to another embodiment of the present invention, there is provided a construction machine including a hydraulic system, a cooling system, and an engine, the construction machine comprising: a first heat exchanger for exchanging heat between the hydraulic fluid of the hydraulic system and the working fluid; And a second heat exchanger for exchanging heat between the working fluid from the cooling system and the cooling water of the cooling system, the system comprising an organic Rankine cycle for circulating the working fluid to heat exchange with the hydraulic system, the cooling system and the waste heat or waste energy of the engine And the first heat exchanger may also serve as an oil cooler for cooling the operating oil.

Wherein the organic Rankine cycle includes a third heat exchanger for exchanging heat between the working fluid from the second heat exchanger and the combustion gas of the engine; A turbine into which the working fluid from the third heat exchanger flows to generate mechanical energy; A condenser for condensing and liquefying the working fluid from the turbine; A storage tank for storing the working fluid from the condenser; And a pump for sending the working fluid stored in the storage tank to the first heat exchanger.

And a fourth heat exchanger provided between the third heat exchanger and the turbine for superheating the working fluid by exchanging heat between the working fluid from the third heat exchanger and the gas discharged from the exhaust gas recirculation system.

When the working fluid from the third heat exchanger or the fourth heat exchanger is not completely vaporized, the working fluid can be bypassed to the first heat exchanger without flowing into the turbine.

The present invention relates to a system for improving fuel economy through recovery of a construction machine by converting the thermal energy of operating oil, cooling water and waste gas discarded in a construction machine having a hydraulic system to a drive source capable of driving the construction machine, The fuel consumption of the construction machine can be reduced.

The system for improving the fuel economy of the construction machine according to the present invention can recover the thermal energy of the operating oil, the cooling water, and the waste gas discharged from the construction machine having the hydraulic system to convert it into a driving source capable of driving the construction machine. The use of the radiator as a heat exchanger not only simplifies the configuration of the fuel consumption improvement system but also increases the amount of heat recovered from the operating oil, cooling water and waste gas.

Furthermore, since the system for improving the fuel economy through the recovery of the piping heat of the construction machine of the present invention can selectively determine the position or the presence or absence of the radiator according to the configuration or the form of the organic Rankine cycle for recovering the waste heat or the waste energy from the construction machine The organic Rankine cycle can be provided in the engine room without much restriction in the engine room of the construction machine.

FIG. 1 is a view showing a configuration of a fuel consumption improvement system through a heat recovery of a construction machine according to an embodiment of the present invention. FIG. 1 is a view showing a fuel consumption improvement system through a heat recovery of a construction machine in which a radiator and a heat exchanger are connected in parallel. to be.
FIG. 2 is a view showing a modification of the fuel consumption improving system through the heat recovery of the construction machine shown in FIG. 1, wherein the radiator is connected to the engine or heat exchanger in series, .
FIG. 3 is a view showing another modification of the fuel consumption improvement system through the heat recovery of the construction machine shown in FIG. 1. FIG. 3 is a view showing a fuel consumption improvement system through the heat recovery of the construction machine in which the radiator is integrated with the heat exchanger.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art to which the present invention pertains. The present invention may be embodied in many different forms and is not limited to the embodiments described herein.

The drawings are schematic and illustrate that they are not drawn to scale. The relative dimensions and ratios of the parts in the figures are shown exaggerated or reduced in size for clarity and convenience in the figures, and any dimensions are merely illustrative and not restrictive. And to the same structure, element or component appearing in more than one drawing, the same reference numerals are used to denote similar features.

The embodiments of the present invention specifically illustrate ideal embodiments of the present invention. As a result, various variations of the drawings are expected. Thus, the embodiment is not limited to any particular form of the depicted area, but includes modifications of the form, for example, by manufacture.

Hereinafter, a fuel efficiency improvement system 100 (hereinafter, referred to as a fuel efficiency improvement system) for recovering heat from a construction machine according to an embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a view showing a configuration of a fuel consumption improvement system through a heat recovery of a construction machine according to an embodiment of the present invention. FIG. 1 is a view showing a fuel consumption improvement system through a heat recovery of a construction machine in which a radiator and a heat exchanger are connected in parallel. And FIG. 2 is a view showing a modified example of the fuel consumption improving system through the heat recovery of the construction machine shown in FIG. 1, wherein the radiator is connected to the engine or heat exchanger in series, And FIG. 3 is a view showing another modified example of the fuel consumption improving system through the heat recovery of the construction machine shown in FIG. 1, wherein the radiator is constructed as a unit with the heat exchanger, .

The fuel economy improvement system 100 according to an embodiment of the present invention to be described below is a system mounted on a construction machine (not shown). Generally, a construction machine includes a lower traveling body having a traveling device driven by a traveling hydraulic motor, a pivoting device driven by a pivoting hydraulic motor, an upper pivoting body provided on the lower traveling body through a pivoting device, A working machine mounted at a central position of the front part of the body, and a cab installed at a left side of the front part of the upper revolving body.

Here, the working machine may include a boom pivotably connected to the upper revolving body, an arm pivotally connected to the boom, and a bucket pivotally connected to the arm. Further, the working machine may have hydraulic cylinders for operating the boom, the arm and the bucket respectively, that is, the boom cylinder, the arm cylinder and the bucket cylinder.

In addition, the construction machine is provided with an engine capable of driving each hydraulic motor, and may be provided with a cooling device capable of cooling the engine.

Such a construction machine includes a hydraulic cylinder including a hydraulic cylinder and a hydraulic motor, and the hydraulic system can operate the working machine by the hydraulic pressure of the operating fluid.

Furthermore, the construction machine has a cooling system for cooling the engine using cooling water, and the cooling system can cool the engine by circulating the cooling water in a radiator provided at one side of the engine or the engine.

The fuel economy enhancement system 100 according to an embodiment of the present invention recovers the hydraulic system of the construction machine, the cooling system, and the engine oil generated or abandoned by the engine to regenerate to electrical energy or mechanical energy, The fuel economy of the construction machine can be increased. At this time, the temperature of the working fluid of the organic Rankine cycle used for waste heat recovery can be sequentially increased by sequentially recovering the waste heat according to the temperature of the waste heat from the hydraulic system, the cooling system and the engine.

1 to 3, a fuel consumption improvement system 100 according to an embodiment of the present invention includes an engine 110 of a construction machine, an engine 110 for heating a working fluid by heat exchange with hydraulic oil of a construction machine, A second heat exchanger 122 that heats the working fluid that has passed through the first heat exchanger 120 by heat exchange with the cooling water of the cooling system of the engine 110, A third heat exchanger 124, a first heat exchanger 120, a second heat exchanger 122 and a third heat exchanger 124 for sequentially heating the working fluid passing through the second heat exchanger 122, A condenser 140 for cooling and condensing the working fluid through the turbine, a storage tank 144 for storing the liquefied working fluid in the condenser 140, And a pump 142 for sending the working fluid of the tank 144 to the first heat exchanger 120.

For reference, the dashed lines shown in Figs. 1 to 3 mean the movement path of the working fluid.

1 to 3, the engine 110 may be a driving source of a construction machine such as an excavator or a wheel loader. In this engine 110, exhaust gas, that is, waste gas may be generated. Further, the engine 110 is provided with a cooling device (not shown) including a cooling water for driving a hydraulic motor (not shown) for driving each component of the construction machine and capable of cooling the engine 110 .

In addition, the fuel efficiency improvement system 100 according to an embodiment of the present invention recovers waste energy of all construction machines driven by a hydraulic pressure system using an Organic Rankine Cycle (ORC) It can be utilized as power of machine.

The organic Rankine cycle may include a storage tank 144, a pump 142, an evaporator (or a boiler), a turbine 130, a condenser 140, etc. in which the working fluid is stored.

The evaporator or boiler of the organic Rankine cycle may be implemented with a first heat exchanger 120, a second heat exchanger 122, and a third heat exchanger 124.

At this time, the organic Rankine cycle uses an organic fluid, which is lower than the boiling point of water, as the operating fluid of the working fluid, such as ammonia, alcohol, R134A, R245FA, organic refrigerant and the like.

The fuel economy improvement system 100 according to an embodiment of the present invention includes an organic Rankine cycle that circulates a working fluid that can exchange heat with hydraulic oil hydraulic oil, cooling water of a cooling system, exhaust gas of an engine, Waste heat can be recycled.

In general, the temperature of the operating oil and the cooling water of the construction machine is not high but has a large amount of heat. Therefore, it is preferable to use a working fluid having a low boiling point at which the working fluid, which exchanges heat with the low-temperature operating fluid or the cooling water, is vaporized. In other words, since the working fluid of the organic Rankine cycle uses an organic refrigerant having low boiling point as a working fluid, the waste heat generated in the construction machine can be efficiently recycled.

The working fluid of the organic Rankine cycle is discharged from the pump 142 and is first subjected to heat exchange with the hydraulic fluid of the hydraulic system. The hydraulic oil pressure of the hydraulic system of the construction machine can be used as the driving source of the pump 142 of the organic Rankine cycle. Therefore, there is no need to generate additional energy to circulate the working fluid of the organic Rankine cycle. For this purpose, it is desirable to configure the hydraulic system of the construction machine to be connected to the pump 142 of the organic Rankine cycle.

To this end, the first heat exchanger 120 may be installed on the hydraulic oil passage of the hydraulic system of the construction machine.

Since the temperature of the working fluid of the organic Rankine cycle is lower than that of the working oil flowing into the first heat exchanger 120, the working fluid obtains heat from the working oil to raise the temperature. On the other hand, do.

The working fluid absorbing the heat of the operating oil in the first heat exchanger (120) flows into the second heat exchanger (122). The second heat exchanger 122 is a place where heat exchange occurs between the cooling water of the cooling system of the construction machine and the working fluid of the organic Rankine cycle. To this end, the second heat exchanger 122 is preferably provided at one side of the cooling system. That is, the second heat exchanger 122 is installed on the cooling water flow path of the cooling system of the construction machine.

Since the temperature of the working fluid is lower than the temperature of the cooling water flowing into the second heat exchanger 122, the working fluid in the second heat exchanger 122 absorbs a lot of heat from the cooling water. Therefore, it can be seen that the cooling water has higher or more heat than the working oil.

The working fluid heat exchanged with the working oil and the cooling water in the first heat exchanger 120 and the second heat exchanger 122 is higher in temperature than the working fluid flowing out of the storage tank 144 but still in a liquid state.

The fuel economy improving system 100 according to an embodiment of the present invention performs heat exchange between the working fluid of the organic Rankine cycle in the liquid state and the waste heat of the construction machine to convert the working fluid into a complete gas state, And the turbine 130 is rotated by the fluid to obtain energy. Therefore, in order to make the working fluid into a gaseous state, there is a necessity to exchange heat with an object having a higher temperature than the working fluid

Here, the fuel efficiency improvement system 100 according to an embodiment of the present invention may further include a radiator 160.

The radiator 160 may be a part of a cooling system that receives cooling water from the cooling system of the construction machine and cools the engine 110.

1, the radiator 160 is provided on the cooling water flow path of the cooling system, and may be provided on one side of the engine 110 so as to be adjacent to the engine 110. [

As described above, the cooling water of the cooling system flows into the second heat exchanger 122, and heat exchange occurs between the working fluid and the cooling water. Here, the cooling water of the cooling system may be introduced into the second heat exchanger 122 or into the radiator 160 after cooling the engine 110. That is, after the engine 110 is cooled, the cooling water may be branched in parallel to flow into the second heat exchanger 122 or the radiator 160.

The radiator 160 and the second heat exchanger 122 may be connected in parallel with the cooling water flow path of the cooling system. A cooling water distributing valve 162 may be provided on the cooling water flow path of the cooling system to branch the cooling water that has cooled the engine 110 to the second heat exchanger 122 or the lidar 160. [ The cooling water in the cooling system can be selectively distributed to the radiator 160 or the second heat exchanger 122 by the cooling water distributing valve 162.

As described above, the cooling water flowing into the second heat exchanger 122 is heat-exchanged with the working fluid and is discharged from the second heat exchanger 122 after the heat is lost. The cooling water discharged from the second heat exchanger 122 And may be introduced into the radiator 160. That is, the cooling water that has cooled the engine 110 or the cooling water that has lost heat in the second heat exchanger 122 may be introduced into the radiator 160.

If the cooling water in the cooling system is not supplied to the radiator 160 and is supplied only to the second heat exchanger 122, the cooling water supplied to the second heat exchanger 122 is supplied to the working fluid from the first heat exchanger 120 Lt; / RTI > At this time, the cooling water flowing into the second heat exchanger 122 exchanges heat with the working fluid to lose heat and the temperature is lowered. The cooling water in this state flows into the radiator 160 and contributes to the heat radiation of the engine 110 do.

On the other hand, the cooling water distributing valve 162 can be opened and closed by comparing the temperature of the cooling water from the engine 110 with the temperature of the cooling water flowing into the radiator 160 or the cooling water coming from the second heat exchanger 122. For example, when the temperature of the cooling water flowing into the radiator 160 or the cooling water emerging from the second heat exchanger 122 is lower than the cooling water emerging from the engine 110, the cooling water distributing valve 162 is opened from the engine 110 And the cooling water can be opened and closed to flow into the second heat exchanger 122. If the temperature of the cooling water flowing into the radiator 160 or the cooling water emerging from the second heat exchanger 122 is higher than the cooling water from the engine 110, And may be opened and closed to contribute to the cooling of the engine 110.

2, one end of the radiator 160 may be connected to the engine 110, that is, the cooling system, and the other end may be connected to the second heat exchanger 122. As shown in FIG. In other words, after the engine 110 is cooled, the cooling water from the engine 110 is directly supplied to the second heat exchanger 122 to perform heat exchange with the working fluid from the first heat exchanger 120, Exchanged cooling water in the radiator 122 is transferred to the radiator 160. The radiator 160, which has received heat from the second heat exchanger 122 and has lost heat and has been cooled down, sends the cooling water to the engine 110 to cool the engine 110. The radiator 160 is connected in series to the cooling system connecting the engine 110 and the second heat exchanger 122 to connect the engine 110, the second heat exchanger 122, and the radiator 160 The cooling water flow path of the cooling system forms a closed circulating flow path so that the heat exchange efficiency in the second heat exchanger 122 can be increased and the engine 110 can be effectively cooled.

Here, a cooling water tank (not shown) may be connected to the cooling water channel of the cooling system into which the cooling water from the second heat exchanger 122 flows into the radiator 160. At this time, it is preferable that a separate valve (not shown) for opening and closing the charge of the cooling water is provided in the cooling water channel connected to the cooling water tank.

3, the radiator 160 is not provided separately from the cooling system or the heat exchangers, but may be provided integrally with the second heat exchanger 122. In other words, as described above, the radiator 160 is not provided separately because it functions as a kind of heat exchanger, and the second heat exchanger 122 may be provided to serve as a radiator. Accordingly, the cooling water in the cooling system is supplied to the second heat exchanger 122, and is directly transferred to the engine 110, that is, cooling water in the cooling system through the second heat exchanger 122. That is, as shown in FIG. 3, since the radiator 160 is not provided separately, the fuel efficiency improvement system 100 can be simply implemented.

Although not shown in the drawing, an oil cooler (not shown) may be provided to cool the operating oil flowing into the first heat exchanger 120. However, in the fuel economy improvement system 100 according to the embodiment of the present invention, the cooling system or the heat exchangers for cooling the operating oil may be provided separately from the cooling system or the heat exchangers, but may be provided integrally with the first heat exchanger 120. In other words, as described above, the oil cooler (not shown) serves as a kind of heat exchanger. Therefore, the first heat exchanger 120 may be provided to serve as an oil cooler have.

The fuel economy improvement system 100 shown in FIG. 3 is the same as the configuration in which the radiator is removed from the fuel economy improvement system 100 shown in FIG. The cooling water that has absorbed the heat of the engine 110 after the engine 110 is cooled and the temperature of which has been increased is directly supplied to the engine 110 and the second heat exchanger 122 122) can form a closed loop flow path.

The cooling water flowing into the second heat exchanger 122 is heat-exchanged with the working fluid to lose heat, and the temperature is lowered, and then the cooling water flows out from the second heat exchanger 122. The cooling water flowing out of the second heat exchanger 122 flows into the engine 110 because the cooling water is sufficiently low enough to cool the engine 110 and can be used for cooling the engine 110.

Here, a cooling water tank (not shown) may be connected to the cooling water channel of the cooling system into which the cooling water from the second heat exchanger 122 flows into the engine 110. At this time, it is preferable that the cooling water channel connected to the cooling water tank is provided with a separate valve (not shown) for opening and closing the channel of the cooling water and a valve driving sensor (not shown) for controlling the opening and closing operation of the valve. The valve drive sensors may be provided in the cooling water flow path from the engine 110 to the second heat exchanger 122 and the cooling water flow path from the second heat exchanger 122 to the engine 110, respectively. The valve driving sensor detects the temperature of the cooling water flowing out of the engine 110 and the cooling water flowing out of the second heat exchanger 122 and compares the detected temperature with each other to operate the valve when the temperature difference is not large enough to cool the cooling water Or may supply the cooling water of the cooling water tank to the engine 110. [

Meanwhile, in the fuel economy improvement system 100 shown in Figs. 1 to 3, the working fluid from the second heat exchanger 122 flows into the third heat exchanger 124. In the third heat exchanger (124), the gas discharged from the engine (110) and the working fluid from the second heat exchanger (122) exchange heat with each other. To this end, the third heat exchanger 124 may be installed on the exhaust gas flow path of the engine 110. Since the temperature of the gas discharged from the engine 110 is higher than the temperature of the working fluid flowing out of the second heat exchanger 122, the working fluid is discharged from the exhaust gas of the engine 110 in the third heat exchanger 124 .

That is, the working fluid is heat-exchanged sequentially with the operating oil, the cooling water, and the exhaust gas from the first heat exchanger 120 through the second heat exchanger 122 and the third heat exchanger 124, thereby increasing the temperature. Since the temperature of the working fluid gradually increases due to the heat exchange with the first heat exchanger 120 and the second heat exchanger 122 as described above, the condition favorable for vaporizing the working fluid through the third heat exchanger 124 .

The first heat exchanger 120 heats the working fluid by exchanging heat from the hydraulic fluid of the hydraulic system and the second heat exchanger 122 performs heat exchange from the cooling water of the cooling system and operates through the first heat exchanger 120 And the third heat exchanger 124 can heat the working fluid passing through the second heat exchanger 122 by heat exchange from the exhaust gas discharged from the engine 110. [

At this time, the temperature T ₃ of the organic working fluid in the third heat exchanger 124 is higher than the temperature T ₂ of the organic working fluid in the second heat exchanger 122, The temperature T ₂ of the organic working fluid in the first heat exchanger 120 may be higher than the temperature T ₁ of the organic working fluid in the first heat exchanger 120. That is, the temperature of the organic working fluid passing through the first heat exchanger 120, the second heat exchanger 122 and the third heat exchanger 124 may be in the order of T ₃ > T ₂ > T ₁ , It means that the state can be changed from the initial liquid state to the gaseous state.

The working fluid vaporized in the first heat exchanger 120, the second heat exchanger 122 and the third heat exchanger 124 flows into the turbine 130 and flows into the turbine 130 via a blade (not shown) Not shown). In other words, the turbine 130 passes the pressure energy of the vaporized working fluid through the first heat exchanger 120, the second heat exchanger 122, and the third heat exchanger 124 in order, It can be converted into mechanical energy.

Meanwhile, a generator (not shown) for generating electric energy may be connected to one side of the rotary shaft of the turbine 130, and a capacitor (not shown) for storing electricity generated from the generator may be provided at one side of the generator. The electrical energy stored in the capacitor can be used to operate the construction machine, thereby improving the fuel economy of the construction machine. In addition, the efficiency of the engine 110 can be increased by connecting rotational energy, i.e., mechanical energy, generated from the rotational axis of the turbine 130 to the engine 110 of the construction machine.

The gaseous working fluid flowing into the turbine 130 rotates the blades of the turbine 130 and the temperature is lowered. The working fluid working in the turbine 130 exits the turbine 130 and flows into the storage tank 144. At this time, the working fluid from the turbine 130 is not a completely liquid state but a mixed state of a gaseous state and a liquid state working fluid and has a certain degree of heat. Therefore, the working fluid must be completely converted to the liquid state before entering the storage tank 144. To this end, the organic Rankine cycle according to one embodiment of the present invention may include a condenser 140 between the turbine 130 and the storage tank 144

The condenser 140 can cool and condense the working fluid through the turbine 130 to liquefy it. In other words, the condenser 140 can change the state of the working fluid through the turbine 130 from the gas state to the liquid state. The working fluid that has been cooled and condensed by the condenser 140 and thus liquefied can be collected and stored in the storage tank 144.

The working fluid in the liquid state collected and stored in the storage tank 144 is sent to either the first heat exchanger 120 or the second heat exchanger 122 or the third heat exchanger 124 by the pump 142 . The pump 142 discharges the organic working fluid stored in the storage tank 144 to the first heat exchanger 120 so that the working fluid flows from the working fluid of the construction machine, the cooling water of the engine 110, Heat exchange with the gas can be made. In this way, the working fluid of the organic Rankine cycle is continuously circulated and heat exchanged in the process to change its state to a gaseous state. By using the waste fluid in the turbine 130, It can be recycled.

In the fuel efficiency improvement system 100 according to an embodiment of the present invention, the working fluid passing through the turbine 130 may be directly transferred to the condenser 140, and the heat energy of the working fluid passing through the turbine 130 may be recovered The first regenerative heat exchanger 150 or the second regenerative heat exchanger 152 can be recycled. That is, if the working fluid from the turbine 130 is not fully liquefied and has some heat, it may be unsuitable for entering the condenser 140 directly. This is because, if the working fluid flowing into the condenser 140 has a certain amount of heat, the condenser 140 must be large in order for the working fluid to be completely liquefied in the condenser 140. However, The condenser 140 may not be used. The temperature of the working fluid flowing into the first heat exchanger 120 or the third heat exchanger 124 may be increased by heat exchange using the heat of the working fluid from the turbine 130. To this end, the fuel economy enhancement system 100 according to an embodiment of the present invention may further include a first regenerative heat exchanger 150 or a second regenerative heat exchanger 152.

1 to 3, the first regenerative heat exchanger 150 can exchange heat between the working fluid passing through the turbine 130 and the working fluid sent out to the pump 142. When it is determined that the temperature of the working fluid that has generated the rotational energy by the turbine 130, that is, the working fluid passing through the turbine 130, is higher than the temperature of the working fluid stored in the storage tank 144, It may be difficult to compress or cool the organic working fluid through the turbine 130. In this case, the first regenerative heat exchanger 150 can be used to exchange heat between the working fluid passing through the turbine 130 and the working fluid sent out from the pump 142. The working fluid sent out from the pump 142, which has been heat-exchanged with the working fluid from the turbine 130 by the first regeneration heat exchanger 150, can be transferred to the first heat exchanger 120 .

The second regenerative heat exchanger 152 can exchange heat between the working fluid passing through the turbine 130 and the working fluid from the second heat exchanger 122. At this time, when the temperature of the working fluid passing through the turbine 130, that is, the working fluid that generates the rotational force to the turbine 130, is higher than the temperature of the working fluid heated in the second heat exchanger 122, The working fluid passing through the turbine 130 and the working fluid passing through the second heat exchanger 122 can be heat exchanged again using the second heat exchanger 152. Thus, the working fluid whose temperature has been increased by the heat exchange by the second regenerative heat exchanger 152 can be transferred to the third heat exchanger 124.

The first regenerative heat exchanger 150 and the second regenerative heat exchanger 152 can not only recycle the thermal energy included in the working fluid from the turbine 130 but also flow into the condenser 140 The working fluid can be completely liquefied in the condenser 140 by sufficiently cooling the working fluid beforehand.

The first regenerative heat exchanger 150 or the second regenerative heat exchanger 152 may be connected to the first regenerative heat exchanger 150 and the second regenerative heat exchanger 152 depending on the size or capacity of the condenser 140. [ All of them may be provided, or only one of them may be provided.

In addition, when the temperature of the working fluid after rotating the turbine 130 is low enough that the working fluid in the condenser 140 is completely liquefied, both the first regenerative heat exchanger 150 and the second regenerative heat exchanger 152 It may not be provided.

On the other hand, the temperature T ₁ 'of the working fluid on the first regenerative heat exchanger 150 may be lower than the temperature T ₂ ' of the working fluid on the second regenerative heat exchanger 152. The temperature of the working fluid on the first regenerative heat exchanger 150 is lower than the working fluid temperature on the first heat exchanger 120 and the temperature of the working fluid on the second regenerative heat exchanger 152 is lower than that of the second heat exchanger 122 Is higher than the temperature of the working fluid.

Meanwhile, the recycling system 100 according to an embodiment of the present invention may further include a fourth heat exchanger 126.

1 to 3, the fourth heat exchanger 126 exchanges heat with the exhaust gas discharged from the engine 110 in the third heat exchanger 124, and thereafter, performs an operation from the third heat exchanger 124 The fluid can be re-heat exchanged. Here, the fourth heat exchanger 126 exchanges heat between the gas discharged from the exhaust gas recirculation (EGR) (not shown) of the engine 110 and the working fluid from the second heat exchanger 122 do. Specifically, the fourth heat exchanger 126 performs superheating of the working fluid by heat exchange between the gas from the exhaust gas recirculation system (EGR) of the engine 110 and the working fluid from the third heat exchanger 124, . In this way, the working fluid that has been heat exchanged again through the fourth heat exchanger 126 is completely vaporized, and the turbine 130 can be rotated.

The temperature T ₄ of the working fluid passing through the fourth heat exchanger 126 may be higher than the temperature T ₃ of the organic working fluid passing through the third heat exchanger 124. Thus, even if the organic working fluid is not completely vaporized by the first heat exchanger 120, the second heat exchanger 122, and the third heat exchanger 124, it can be completely vaporized by the fourth heat exchanger 126 .

Although the working fluid that has been heat-exchanged with the waste gas of the engine 110 in the third heat exchanger 124 is completely vaporized, the working fluid that has passed through the third heat exchanger 124 flows into the fourth heat exchanger 126 To be bypassed to the turbine (130).

Specifically, even if it is determined that the liquid working fluid has been completely converted to the gaseous state through the first heat exchanger 120, the second heat exchanger 122, and the third heat exchanger 124, The working fluid may be introduced into the turbine 130 after the superheating via the fourth heat exchanger 126 is performed. In this case, as the working fluid from the third heat exchanger 124 passes through the fourth heat exchanger 126, the temperature of the working fluid further increases and the energy value for rotating the turbine 130, that is, And as a result, the amount of work output from the turbine 130 can be increased. In other words, since the value of the energy of the rough working fluid through the third heat exchanger 124 to the fourth heat exchanger 126 is greater than the value of the energy of the working fluid passing through the third heat exchanger 124, Can be rotated more quickly. Therefore, even if the working fluid passing through the third heat exchanger 124 is completely converted to the gaseous state, the energy value of the working fluid may be made larger by allowing it to pass through the fourth heat exchanger 126.

However, when the working fluid, which is liquid, is completely converted to the gaseous state through the first heat exchanger 120, the second heat exchanger 122 and the third heat exchanger 124, the fourth heat exchanger 126 is omitted You may. That is, in the case where the working fluid is vaporized 100% even though only the third heat exchanger 124, it is possible to configure the fuel efficiency improvement system 100 according to the embodiment of the present invention without the fourth heat exchanger 126.

If it is detected that the working fluid that has been heat exchanged again with the exhaust gas of the engine 110 in the fourth heat exchanger 126 is not completely vaporized, the first regenerative heat exchanger 150 And can be bypassed to the second regenerative heat exchanger 152.

Specifically, when the working fluid in the liquid state is not completely converted to the gaseous state while passing through the first heat exchanger 120, the second heat exchanger 122, the third heat exchanger 124 and the fourth heat exchanger 126 The first regenerative heat exchanger 150 or the second regenerative heat exchanger 150 may be connected to the first regenerative heat exchanger 150 or the second regenerative heat exchanger 150 through the first bypass flow path 171. [ To be transmitted to the antenna 152. This is because the working fluid in the liquid state is completely vaporized through the first heat exchanger 120, the second heat exchanger 122, the third heat exchanger 124 and the fourth heat exchanger 126 as described above This is because when the working fluid enters the turbine 130 in a liquid state, there is a danger that the turbine 130 will not rotate properly and damage the blade (not shown) of the turbine 130. Accordingly, when it is determined that the working fluid passing through the fourth heat exchanger 126 is not completely vaporized by using the sensing sensor 170 provided between the fourth heat exchanger 126 and the turbine 130, The flow path to the turbine 130 is blocked using the path valve 172 and the working fluid from the fourth heat exchanger 126 flows toward the first regenerative heat exchanger 150 or the second regenerative heat exchanger 152 Only the Euro shall be opened.

As described above, the sensing sensor 170 may be provided as a sensor capable of sensing the state of the working fluid. In other words, the sensing sensor 170 may be a temperature sensing sensor that senses the temperature of the working fluid or may be a pressure sensing sensor capable of sensing a phase change of the working fluid, that is, the volume or pressure of the working fluid . However, the present invention is not limited thereto, and may be various types of detection sensors depending on the physical properties of the working fluid.

Referring to FIGS. 1 to 3, the flow of the working fluid and the heat exchange with the operating oil, the cooling water, and the exhaust gas discharged from the construction machine in the fuel consumption improving system 100 through the pyrolysis recovery of the construction machine according to the embodiment of the present invention Will be described.

First, the working fluid stored in the storage tank 144 may be sent to the first heat exchanger 120 by the pump 142. At this time, the delivered working fluid may be in a liquid state. At this time, the pump 142 can be operated by the hydraulic oil pressure of the hydraulic system of the construction machine.

Then, the liquid working fluid sent to the first heat exchanger 120 by the pump 142 can be heat-exchanged with the working fluid after being used in the hydraulic system of the construction machine. At this time, the use of the working fluid of the construction machine as the waste energy is because the waste fluid energy of the construction machine has the lowest temperature but has a lot of heat. On the other hand, the operating fluid after heat exchange with the working fluid can be recovered to a drain tank (not shown) of the construction machine.

The working fluid heat exchanged in the first heat exchanger 120 may then be transferred to the second heat exchanger 122. In the second heat exchanger (122), the working fluid passing through the first heat exchanger (120) and the cooling system cooling the heat of the engine (110) of the construction machine can be heat exchanged. At this time, utilizing the cooling water used for cooling the engine 110 as waste energy has the next higher temperature than the above-mentioned operating oil. On the other hand, the cooling water exchanged with the working fluid through the first heat exchanger 120 can be drained to a cooling water tank (not shown) of the cooling system of the construction machine.

The working fluid that has been heat exchanged in the second heat exchanger 122 may then be transferred to the third heat exchanger 124. In the third heat exchanger (124), the working fluid passing through the second heat exchanger (122) and the exhaust gas discharged from the engine (110) of the construction machine can be heat exchanged. At this time, the exhaust gas discharged from the engine 110 is utilized as waste energy because it has the next higher temperature than the above-mentioned cooling water. In addition, since the waste gas discharged from the engine 110 has a considerably high temperature, there is a risk that the exhaust gas discharged from the engine 110 may be injured by the exhaust gas. On the other hand, the exhaust gas that has been heat-exchanged with the working fluid transferred through the second heat exchanger 122 can be discharged to the outside of the construction machine.

The working fluid, which has been heat exchanged in the third heat exchanger (124) and is in a gaseous state, may then be transferred to the turbine (130) to rotate the turbine (130).

At this time, when the temperature of the working fluid after generating the electric power by rotating the turbine 130 is higher than the temperature of the working fluid stored in the storage tank 144, electric power is generated using the first regenerative heat exchanger 150 The working fluid after the heating operation and the working fluid sent out by the pump 142 can be heat-exchanged again.

When the temperature of the working fluid after generating the electric power is higher than the temperature of the working fluid heated in the second heat exchanger 122, the working fluid passing through the turbine 130 and the working fluid passing through the second heat exchanger 122 The working fluid can be heat-exchanged again.

The first regenerative heat exchanger 150 or the second regenerative heat exchanger 152 may be installed in the first regenerative heat exchanger 150 and the second regenerative heat exchanger 152 depending on the size and the capacity of the condenser 140, Or only one of the first regenerative heat exchanger 150 or the second regenerative heat exchanger 152 may be provided.

When it is judged that the working fluid passing through the third heat exchanger 124 has not been converted from the initial liquid state to the complete gas state, it is discharged from the exhaust gas recirculation system (EGR) having a higher temperature than the exhaust gas of the engine 110 And a fourth heat exchanger 126 provided for exchanging heat between the gas and the working fluid. In the fourth heat exchanger 126, the working fluid passing through the third heat exchanger 124 and the gas discharged from the exhaust gas recirculation system (EGR) of the construction machine can be heat-exchanged.

For reference, the operating fluid passing through the third heat exchanger 124 may pass through the fourth heat exchanger 126 even if it is determined that the working fluid passing through the third heat exchanger 124 is completely vaporized. This is because when the working fluid passing through the third heat exchanger 124 is superheated through the fourth heat exchanger 126, the amount of work or the turning force from the turbine 130 becomes larger. Therefore, even if it is determined that the working fluid has completely vaporized after passing through the third heat exchanger 124, it is preferable that the working fluid passing through the third heat exchanger 124 passes through the fourth heat exchanger 126.

Next, the working fluid after rotating the turbine 130 to generate electric power is immediately transferred to the condenser 140 and stored in the storage tank 144 as a working fluid in liquid state, or the first regenerative heat exchanger 150, Or the second regenerative heat exchanger 152 and then transferred to the condenser 140 and stored in the storage tank 144 as a liquid working fluid.

According to the above-described configuration, the system 100 for improving the fuel economy of the construction machine according to the embodiment of the present invention recovers the thermal energy of the operating oil, the cooling water, and the waste gas discarded in the construction machine having the hydraulic system It can be converted into a drive source capable of driving the construction machine. As a result, the fuel consumption of the construction machine can be reduced.

In addition, since the system 100 for improving the fuel economy of the construction machine according to the embodiment of the present invention does not require a separate radiator by utilizing the heat exchanger constituting the organic Rankine cycle as a radiator, Can be simplified.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Accordingly, the spirit of the present invention should not be construed as being limited to the embodiments described, and all of the equivalents or equivalents of the claims, as well as the following claims, belong to the scope of the present invention .

100: Fuel economy improvement system through recovery of construction machinery
110: engine
120: first heat exchanger 122: second heat exchanger
124: third heat exchanger 126: fourth heat exchanger
130: Turbine
140: condenser 142: pump
144: Storage tank
150: first regenerative heat exchanger 152: second regenerative heat exchanger
160: radiator 162: cooling water distribution valve
170: Detection sensor
171: first bypass passage 172: first bypass valve

Claims (11)

1. A construction machine comprising a hydraulic system, a cooling system, and an engine,
A first heat exchanger for exchanging heat between the working fluid and the working fluid of the hydraulic system and a second heat exchanger for exchanging heat between the working fluid from the first heat exchanger and the cooling water of the cooling system, An organic Rankine cycle for circulating the working fluid so as to cause heat exchange with the system and the waste heat or waste energy of the engine in order so that the temperature of the working fluid becomes gradually higher and is favorable for vaporization; And
A radiator provided at one side of the engine and supplied with cooling water of the cooling system;
/ RTI >
The cooling water in the cooling system flows into the second heat exchanger to cause heat exchange between the working fluid and the cooling water. The cooling water in the cooling system is branched in parallel after cooling the engine, Lt; / RTI >
The temperature of the cooling water coming from the engine and the cooling water flowing into the radiator or the cooling water coming out of the second heat exchanger is compared with the temperature of the cooling system flowing out from the engine, A cooling water distribution valve for selectively distributing the cooling water to the radiator or the second heat exchanger is provided,
When the temperature of the cooling water flowing into the radiator or the cooling water emerging from the second heat exchanger is lower than the cooling water emerging from the engine, the cooling water distribution valve is opened and closed so that the cooling water from the engine flows into the second heat exchanger, When the temperature of the cooling water flowing into the radiator or the cooling water flowing out of the second heat exchanger is higher than the cooling water flowing out of the radiator, the cooling water distributing valve is opened and closed so that cooling water from the engine flows into the radiator and contributes to cooling of the engine A system to improve fuel efficiency through recovery of waste heat from construction machinery.
delete delete 1. A construction machine comprising a hydraulic system, a cooling system, and an engine,
A first heat exchanger for exchanging heat between the hydraulic fluid of the hydraulic system and the working fluid, and a second heat exchanger for exchanging the working fluid from the first heat exchanger with the cooling water of the cooling system, wherein the hydraulic system, An organic Rankine cycle in which the working fluid is circulated such that heat exchange with the waste heat or the waste energy of the engine is carried out successively so that the temperature of the working fluid becomes gradually higher and is favorable for vaporization;
A radiator provided at one side of the engine and supplied with cooling water of the cooling system; / RTI >
One end of the radiator is connected to the engine and the other end is connected to the second heat exchanger to cool the engine and then the cooling water from the engine is supplied directly to the second heat exchanger and the working fluid from the first heat exchanger Exchanged with the radiator, and the cooling water subjected to heat exchange and heat-exchanged in the second heat exchanger is transferred to the radiator,
The radiator, which has been heat-exchanged in the second heat exchanger and has received the cooling water whose temperature has been decreased, is sent to the engine to cool the engine, and the radiator is connected in series to the cooling system connecting the engine and the second heat exchanger And the cooling water flow path of the cooling system connecting the engine, the second heat exchanger, and the radiator forms a closed circulation flow path.
delete 1. A construction machine comprising a hydraulic system, a cooling system, and an engine,
A first heat exchanger for exchanging heat between the hydraulic fluid of the hydraulic system and the working fluid, and a second heat exchanger for exchanging the working fluid from the first heat exchanger with the cooling water of the cooling system, wherein the hydraulic system, An organic Rankine cycle in which the working fluid is circulated such that heat exchange with the waste heat or the waste energy of the engine is carried out successively so that the temperature of the working fluid becomes gradually higher and is favorable for vaporization;
A cooling water tank in which cooling water from the second heat exchanger is connected to a cooling water flow path of a cooling system into which the cooling water flows;
A valve provided in a cooling water passage connected to the cooling water tank to open and close a cooling water passage; And
A valve drive sensor for controlling the opening and closing operation of the valve;
/ RTI >
The cooling water of the cooling system is supplied to the second heat exchanger and then directly from the second heat exchanger to the engine so that the second heat exchanger serves as a radiator,
The cooling water flow path of the cooling system connecting the engine and the second heat exchanger forms a closed circulation flow path so that the cooling water introduced into the second heat exchanger exchanges heat with the working fluid to lose heat and the temperature is lowered, And the cooling water flowing out of the second heat exchanger flows into the engine immediately to cool the engine and is used for cooling the engine,
Wherein the valve driving sensor is provided in each of a cooling water flow path from the engine to the second heat exchanger and a cooling water flow path from the second heat exchanger to the engine and includes cooling water flowing out from the engine and cooling water flowing out from the second heat exchanger And when the temperature difference is not large, the valve is operated to supply the cooling water to the cooling water tank or to supply the cooling water of the cooling water tank to the engine. Fuel economy improvement system.
delete The method according to claim 6,
And the first heat exchanger also serves as an oil cooler for cooling the operating oil.
The method according to any one of claims 1, 4, 6, and 8,
The organic Rankine cycle may comprise:
A third heat exchanger for exchanging heat between the working fluid from the second heat exchanger and the combustion gas of the engine;
A turbine into which the working fluid from the third heat exchanger flows to generate mechanical energy;
A condenser for condensing and liquefying the working fluid from the turbine;
A storage tank for storing the working fluid from the condenser; And
A pump for sending the working fluid stored in the storage tank to the first heat exchanger;
Wherein the system further comprises a control unit for controlling the operation of the engine.
10. The method of claim 9,
And a fourth heat exchanger provided between the third heat exchanger and the turbine for superheating the working fluid by exchanging heat between the working fluid from the third heat exchanger and the gas discharged from the exhaust gas recirculation system Fuel economy improvement system through the recovery of construction machinery.
11. The method of claim 10,
When the working fluid from the third heat exchanger or the fourth heat exchanger is not completely vaporized, bypasses the first heat exchanger to the first heat exchanger without flowing into the turbine. Enhancement system.

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