CN214887383U

CN214887383U - Waste heat recovery equipment

Info

Publication number: CN214887383U
Application number: CN202121047558.7U
Authority: CN
Inventors: 吴琼; 查万春; 周立宾
Original assignee: Yantai Jereh Petroleum Equipment and Technologies Co Ltd
Current assignee: Yantai Jereh Petroleum Equipment and Technologies Co Ltd
Priority date: 2021-05-17
Filing date: 2021-05-17
Publication date: 2021-11-26
Anticipated expiration: 2031-05-17

Abstract

The application provides a waste heat recovery device, relates to oil gas exploitation technical field, solves the technical problem that the mode of present gasification liquid nitrogen causes a large amount of fuel consumption. The waste heat recovery device comprises a liquid nitrogen storage tank, a first heat exchanger, an oil tank, a power assembly, a first liquid nitrogen conveying pipeline, an oil output pipeline and an oil input pipeline; the first heat exchanger is provided with a liquid nitrogen inlet, a liquid nitrogen outlet, an oil inlet and an oil outlet; an outlet of the liquid nitrogen storage tank is communicated with a liquid nitrogen inlet of the first heat exchanger through the first liquid nitrogen conveying pipeline; the outlet of the oil tank is communicated with the oil inlet of the power assembly through the oil output pipeline, the oil outlet of the power assembly is communicated with the oil inlet of the first heat exchanger, and the oil outlet of the first heat exchanger is communicated with the inlet of the oil tank through the oil input pipeline. The application provides a waste heat recovery equipment is used for gasifying liquid nitrogen.

Description

Waste heat recovery equipment

Technical Field

The application relates to the technical field of oil and gas exploitation, in particular to waste heat recovery equipment.

Background

In the field of oil and gas exploitation, nitrogen is increasingly widely applied in fracturing operations.

At present, nitrogen is generally obtained by heating and gasifying liquid nitrogen through a direct-fired evaporator. Since the direct-fired evaporator heats the liquid nitrogen by the heat generated by burning the fuel oil, this way of vaporizing the liquid nitrogen causes a large consumption of fuel.

SUMMERY OF THE UTILITY MODEL

The utility model provides a waste heat recovery equipment can be used for solving the technical problem that the mode of present gasification liquid nitrogen causes a large amount of consumptions of fuel.

The embodiment of the application provides waste heat recovery equipment, which comprises a liquid nitrogen storage tank, a first heat exchanger, an oil tank, a power assembly, a first liquid nitrogen conveying pipeline, an oil output pipeline and an oil input pipeline;

the first heat exchanger is provided with a liquid nitrogen inlet, a liquid nitrogen outlet, an oil inlet and an oil outlet;

an outlet of the liquid nitrogen storage tank is communicated with a liquid nitrogen inlet of the first heat exchanger through the first liquid nitrogen conveying pipeline;

the outlet of the oil tank is communicated with the oil inlet of the power assembly through the oil output pipeline, the oil outlet of the power assembly is communicated with the oil inlet of the first heat exchanger, and the oil outlet of the first heat exchanger is communicated with the inlet of the oil tank through the oil input pipeline.

Optionally, in one embodiment, the power assembly comprises a generator, a speed reducer and a gas turbine, and the oil tank is a lubricating oil tank;

the generator is connected with the gas turbine through the speed reducer, and an outlet of the lubricating oil tank is respectively communicated with a lubricating oil inlet of the generator, a lubricating oil inlet of the speed reducer and a lubricating oil inlet of the gas turbine through the oil output pipeline;

at least one of the lubricating oil outlet of the generator, the lubricating oil outlet of the speed reducer and the lubricating oil outlet of the gas turbine is communicated with the oil inlet of the first heat exchanger.

Optionally, in one embodiment, the waste heat recovery apparatus further comprises a second heat exchanger, a gas turbine air inlet pipeline and a second liquid nitrogen conveying pipeline;

the second heat exchanger is provided with a liquid nitrogen inlet, a liquid nitrogen outlet, an air inlet and an air outlet;

an outlet of the liquid nitrogen storage tank is communicated with a liquid nitrogen inlet of the second heat exchanger through the second liquid nitrogen conveying pipeline;

and the air outlet of the second heat exchanger is communicated with the air inlet of the gas turbine through the gas turbine air inlet pipeline.

Optionally, in an embodiment, the waste heat recovery apparatus further includes a first temperature sensor and a first valve;

the first temperature sensor is positioned at an air outlet of the second heat exchanger, and the first valve is arranged at a first position of the second liquid nitrogen conveying pipeline.

Optionally, in one embodiment, the waste heat recovery device further comprises a tank with a vent, a third heat exchanger, a tank inlet pipeline and a third liquid nitrogen conveying pipeline;

the generator, the speed reducer and the gas turbine are arranged inside the box body;

the third heat exchanger is provided with a liquid nitrogen inlet, a liquid nitrogen outlet, an air inlet and an air outlet;

an outlet of the liquid nitrogen storage tank is communicated with a liquid nitrogen inlet of the third heat exchanger through the third liquid nitrogen conveying pipeline;

and an air outlet of the third heat exchanger is communicated with a ventilation opening of the box body through the box body air inlet pipeline.

Optionally, in an embodiment, the waste heat recovery apparatus further includes a fourth heat exchanger, a tail gas output pipeline, and a fourth liquid nitrogen delivery pipeline;

the fourth heat exchanger is provided with a liquid nitrogen inlet, a liquid nitrogen outlet, a tail gas inlet and a tail gas outlet;

an outlet of the liquid nitrogen storage tank is communicated with a liquid nitrogen inlet of the fourth heat exchanger through the fourth liquid nitrogen conveying pipeline;

and a tail gas outlet of the gas turbine is communicated with a tail gas inlet of the fourth heat exchanger through the tail gas output pipeline.

Optionally, in an embodiment, the waste heat recovery apparatus further includes a tail gas output branch and a second valve;

and the inlet of the tail gas output branch is communicated with the second position of the tail gas output pipeline through the second valve.

Optionally, in an embodiment, the waste heat recovery apparatus further includes a second temperature sensor;

the second temperature sensor is arranged at a liquid nitrogen outlet of the fourth heat exchanger.

Optionally, in an embodiment, the waste heat recovery apparatus further includes a liquid nitrogen inflow pipe and a separation device;

and the liquid nitrogen outlet of the first heat exchanger, the liquid nitrogen outlet of the second heat exchanger, the liquid nitrogen outlet of the third heat exchanger and the liquid nitrogen outlet of the fourth heat exchanger are communicated with the inlet of the liquid nitrogen gathering pipeline, and the outlet of the liquid nitrogen gathering pipeline is communicated with the inlet of the separation device.

Optionally, in an embodiment, the waste heat recovery apparatus further comprises a delivery pump;

an outlet of the liquid nitrogen storage tank is communicated with an inlet of the delivery pump, and an outlet of the delivery pump is respectively communicated with an inlet of the first liquid nitrogen delivery pipeline, an inlet of the second liquid nitrogen delivery pipeline, an inlet of the third liquid nitrogen delivery pipeline and an inlet of the fourth liquid nitrogen delivery pipeline.

The utility model discloses the beneficial effect who brings as follows:

by adopting the waste heat recovery equipment provided by the embodiment of the application, the waste heat recovery equipment comprises a liquid nitrogen storage tank, a first heat exchanger, an oil tank, a power assembly, a first liquid nitrogen conveying pipeline, an oil output pipeline and an oil input pipeline; the first heat exchanger is provided with a liquid nitrogen inlet, a liquid nitrogen outlet, an oil inlet and an oil outlet; an outlet of the liquid nitrogen storage tank is communicated with a liquid nitrogen inlet of the first heat exchanger through the first liquid nitrogen conveying pipeline; an outlet of the oil tank is communicated with an oil inlet of the power assembly through the oil output pipeline, an oil outlet of the power assembly is communicated with an oil inlet of the first heat exchanger, and an oil outlet of the first heat exchanger is communicated with an inlet of the oil tank through the oil input pipeline; make the oil of carrying power component through oil output pipeline can absorb power component's waste heat, in first heat exchanger, the oil that has absorbed the waste heat can give the liquid nitrogen with the heat transfer in order to heat the liquid nitrogen to liquid nitrogen gasification obtains nitrogen gas, makes the liquid nitrogen can utilize the waste heat of recovery to gasify, has practiced thrift the use of the fuel energy.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts. In the drawings:

fig. 1 is a schematic structural diagram of a waste heat recovery apparatus according to an embodiment of the present disclosure;

fig. 2 is a schematic structural diagram of another waste heat recovery device provided in an embodiment of the present application;

fig. 3 is a schematic structural diagram of another waste heat recovery device provided in the embodiment of the present application;

fig. 4 is a schematic structural diagram of another waste heat recovery device provided in the embodiment of the present application;

fig. 5 is a schematic structural diagram of another waste heat recovery device provided in the embodiment of the present application;

FIG. 6 is a schematic structural diagram of another waste heat recovery device provided in the embodiment of the present application;

FIG. 7 is a schematic structural diagram of another waste heat recovery apparatus provided in the embodiment of the present application;

FIG. 8 is a schematic structural diagram of another waste heat recovery apparatus provided in the embodiment of the present application;

9-1 and 9-2 are schematic structural diagrams of still another waste heat recovery device provided by the embodiment of the application;

fig. 10 is a schematic structural diagram of another waste heat recovery device provided in the embodiment of the present application;

fig. 11 is a schematic structural diagram of another waste heat recovery apparatus provided in the embodiment of the present application;

fig. 12 is a schematic structural diagram of another waste heat recovery apparatus provided in the embodiment of the present application;

fig. 13 is a schematic structural diagram of another waste heat recovery apparatus provided in the embodiment of the present application;

fig. 14 is a schematic structural diagram of another waste heat recovery device provided in the embodiment of the present application;

fig. 15 is a schematic structural diagram of another waste heat recovery device according to an embodiment of the present application.

Reference numerals:

10-waste heat recovery equipment; 101-liquid nitrogen storage tank; 102 — a first heat exchanger; 103-oil tank; 104-a power assembly; 1041 — an electric generator; 1042 — a reducer; 1043 — gas turbine; 105-a first liquid nitrogen delivery line; 106-oil output line; 107-oil input line; 108 — a second heat exchanger; 109-gas turbine inlet line; 110-second liquid nitrogen delivery line; 111 — a first temperature sensor; 112 — a first valve; 113-a box body; 1131 — vent; 114 — a third heat exchanger; 115-tank inlet line; 116-a third liquid nitrogen delivery line; 117-blower; 118 — a fourth heat exchanger; 119-a tail gas output pipeline; 120-fourth liquid nitrogen delivery line; 121-tail gas output branch; 122 — a second valve; 123 — a second temperature sensor; 124, liquid nitrogen is collected into a pipeline; 125-a separation device; 126-pressure regulating means; 127-transfer pump.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the technical solutions of the present application will be described in detail and completely with reference to the following specific embodiments of the present application and the accompanying drawings. It should be apparent that the described embodiments are only some of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The features of the terms first and second in the description and in the claims of the present application may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more unless otherwise specified. In addition, "and/or" in the specification and claims means at least one of connected objects, a character "/" generally means that a preceding and succeeding related objects are in an "or" relationship.

In the description of the present application, it is to be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the present application and for simplicity in description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the present application.

In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

Based on the fact that the way of gasifying liquid nitrogen in the related art causes a large consumption of fuel as described in the background of the present application, the present embodiment provides a waste heat recovery apparatus 10 for solving the above technical problems. As shown in fig. 1, the waste heat recovery device 10 includes a liquid nitrogen storage tank 101, a first heat exchanger 102, an oil tank 103, a power assembly 104, a first liquid nitrogen conveying pipeline 105, an oil output pipeline 106, and an oil input pipeline 107; the first heat exchanger 102 has a liquid nitrogen inlet, a liquid nitrogen outlet, an oil inlet and an oil outlet; an outlet of the liquid nitrogen storage tank 101 is communicated with a liquid nitrogen inlet of the first heat exchanger 102 through the first liquid nitrogen conveying pipeline 105; an outlet of the oil tank 103 is communicated with an oil inlet of the power assembly 104 through the oil output pipeline 106, an oil outlet of the power assembly 104 is communicated with an oil inlet of the first heat exchanger 102, and an oil outlet of the first heat exchanger 102 is communicated with an inlet of the oil tank 103 through the oil input pipeline 107.

The liquid nitrogen storage tank 101 may be used to store liquid nitrogen, among other things.

The first heat exchanger 102 may be configured to exchange heat between oil and liquid nitrogen, specifically, the heat exchange process may be that the oil absorbing the waste heat enters the first heat exchanger 102 from an oil inlet of the first heat exchanger 102, and the liquid nitrogen enters the first heat exchanger 102 from a liquid nitrogen inlet of the first heat exchanger 102; the temperature difference exists between the oil absorbing the waste heat and the liquid nitrogen, and in the first heat exchanger 102, the liquid nitrogen absorbs heat and is gasified into nitrogen gas and then flows out of a liquid nitrogen outlet of the first heat exchanger 102; the oil transfers heat to the liquid nitrogen and then the temperature is reduced, and the oil with the reduced temperature flows out from the oil outlet of the first heat exchanger 102. The first heat exchanger 102 may be a dividing wall type heat exchanger, and specifically may be a shell-and-tube heat exchanger, a double-tube heat exchanger, or the like. It should be understood that the above-mentioned types of the first heat exchanger 102 are only examples, and do not represent a limitation to the types of the first heat exchanger 102, and in practical applications, the types of the first heat exchanger 102 may be selected according to actual needs.

The oil tank 103 may be used to temporarily store oil. The type of oil stored in the oil tank 103 may be set according to the type of the power module 104. For example, when the power assembly is a gas turbine generator set, lubricating oil can be stored in the oil tank 103, and the lubricating oil can take away waste heat when entering the gas turbine generator set; when the power assembly is a hydraulic assembly, the oil tank 103 stores hydraulic oil, and the hydraulic oil enters the hydraulic assembly to take away waste heat. It should be understood that the above examples are only examples, and do not represent a limitation on the type of oil stored in the oil tank 103 and the type of the power assembly 104, and in practical applications, the type of oil stored in the oil tank 103 and the type of the power assembly 104 may be set according to actual needs. The oil tank 103 has an outlet for feeding oil to the oil outlet line 106 and an inlet for feeding oil to the oil tank 103 via the oil feed line 107; the oil tank 103, the oil output line 106 and the oil input line 107 constitute a circulation loop in which oil circulates, and in order to facilitate the oil to be able to circulate in the circulation loop, an oil pump may be provided at an outlet position of the oil tank 103 to provide a delivery power.

The power assembly 104 may be an assembly that outputs power through energy conversion. For example, power assembly 104 may be a gas turbine power plant that converts chemical energy into electrical energy to provide electricity, an engine power plant that converts chemical energy into mechanical energy to provide power, and so forth. During the energy conversion process, a part of the energy is dissipated as heat, that is, the power assembly 104 generates heat during the operation.

The oil output line 106 may be used to input oil into the power module 104, which may absorb excess heat from the power module 104. The oil inlet line 107 may be used to transfer oil back to the tank 103 for the next circulation.

It can be understood that through the waste heat recovery device 10 that this application embodiment provided for the oil of carrying power component 104 through oil output pipeline 106 can absorb the waste heat of power component 104, and in first heat exchanger 102, the oil that has absorbed the waste heat can give the liquid nitrogen with heat transfer in order to heat the liquid nitrogen, thereby liquid nitrogen gasification obtains nitrogen gas, makes the liquid nitrogen can utilize the waste heat of recovery to gasify, has practiced thrift the use of the fuel energy.

The gas turbine generator set has the advantages of high output power, high energy density, low noise, low emission and the like, and has a wide application prospect in the field of oil and gas exploitation. In view of this, in the waste heat recovery apparatus 10 according to the embodiment of the present application, the power assembly 104 includes a generator 1041, a reducer 1042 and a gas turbine 1043, as shown in fig. 2, the oil tank 103 is a lubricating oil tank; the generator 1041 is connected to the gas turbine 1043 through the speed reducer 1042, and an outlet of the lubricating oil tank is respectively communicated with a lubricating oil inlet of the generator 1041, a lubricating oil inlet of the speed reducer 1042 and a lubricating oil inlet of the gas turbine 1043 through the oil output pipeline 106; at least one of the lubricant outlet of the generator 1041, the lubricant outlet of the decelerator 1042, and the lubricant outlet of the gas turbine 1043 is communicated with the oil inlet of the first heat exchanger 102.

The generator 1041, the reducer 1042 and the gas turbine 1043 are connected in sequence to form a gas turbine generator set. The gas turbine 1043 may convert chemical energy into mechanical energy; specifically, the gas turbine 1043 includes a compressor, a combustion chamber, and a turbine connected in sequence, the compressor is configured to continuously suck air and compress the air to supply the air to the combustion chamber, the compressed air and injected fuel are combusted in the combustion chamber to become high-temperature gas, and the high-temperature gas enters the turbine to perform expansion work, so as to convert internal energy into mechanical energy. Further, the gas turbine 1043 transmits mechanical energy to the generator 1041 through the speed reducer 1042, and the generator 1041 generates electricity by reusing the mechanical energy. The reducer 1042 can match the rotation speed and transmit torque between the gas turbine 1043 and the generator 1041, so that the generator 1041 can smoothly generate electricity by using mechanical energy. The reducer 1042 may generally be composed of a transmission part (gear or worm), a shaft, a bearing, a case, and the like.

The oil tank 103 is a lubricating oil tank, and it is understood that lubricating oil is stored in the oil tank 103, and the oil output pipeline 106 and the oil input pipeline are used for conveying lubricating oil. Lubricating oil which is input into the generator 1041, the reducer 1042 and the gas turbine 1043 through the oil output pipeline 106 can absorb waste heat in the process of lubricating various parts in the generator 1041, the reducer 1042 and the gas turbine 1043.

It should be noted that at least one of the lubricant outlet of the generator 1041, the lubricant outlet of the reducer 1042, and the lubricant outlet of the gas turbine 1043 is in communication with the oil inlet of the first heat exchanger 102, and specifically, may be:

in one embodiment, the lubricant outlet of the generator 1041 is in communication with the oil inlet of the first heat exchanger 102, the oil outlet of the first heat exchanger 102 is in communication with the inlet of the oil input line 107, the lubricant outlet of the reducer 1042 is in communication with the inlet of the oil input line 107, and the lubricant outlet of the gas turbine 1043 is in communication with the inlet of the oil input line 107, as shown in fig. 3. In the first heat exchanger 102, the liquid nitrogen exchanges heat with the lubricating oil absorbing the residual heat of the generator 1041, the nitrogen gas absorbing the heat vaporization flows out from the liquid nitrogen outlet of the first heat exchanger 102, and the lubricating oil with the reduced temperature flows out from the oil outlet of the first heat exchanger 102 and returns to the oil tank 103 through the oil input pipe 107. Meanwhile, the lubricating oil directly returns to the oil tank 103 through the oil input pipe 107 after absorbing the residual heat of the reducer 1042, and the lubricating oil directly returns to the oil tank 103 through the oil input pipe 107 after absorbing the residual heat of the gas turbine 1043. That is, in the first heat exchanger 102, the recovered waste heat of the generator 1041 is used to heat the liquid nitrogen.

In another embodiment, the lubricant outlet of the speed reducer 1042 is communicated with the oil inlet of the first heat exchanger 102, the oil outlet of the first heat exchanger 102 is communicated with the inlet of the oil input pipeline 107, the lubricant outlet of the generator 1041 is communicated with the inlet of the oil input pipeline 107, and the lubricant outlet of the gas turbine 1043 is communicated with the inlet of the oil input pipeline 107, as shown in fig. 4. In the first heat exchanger 102, the liquid nitrogen exchanges heat with the lubricating oil absorbing the residual heat of the reducer 1042, the nitrogen gas absorbing the heat and being gasified flows out from the liquid nitrogen outlet of the first heat exchanger 102, and the lubricating oil having the reduced temperature flows out from the oil outlet of the first heat exchanger 102 and returns to the oil tank 103 through the oil input pipe 107. Meanwhile, the lubricating oil directly returns to the oil tank 103 through the oil input pipeline 107 after absorbing the waste heat of the generator 1041, and the lubricating oil directly returns to the oil tank 103 through the oil input pipeline 107 after absorbing the waste heat of the gas turbine 1043. That is, in the first heat exchanger 102, the recovered waste heat of the decelerator 1042 is used to heat the liquid nitrogen.

In yet another embodiment, the lubricant outlet of the gas turbine 1043 is communicated with the oil inlet of the first heat exchanger 102, the oil outlet of the first heat exchanger 102 is communicated with the inlet of the oil input line 107, the lubricant outlet of the generator 1041 is communicated with the inlet of the oil input line 107, and the lubricant outlet of the reducer 1042 is communicated with the inlet of the oil input line 107, as shown in fig. 5. In the first heat exchanger 102, the liquid nitrogen exchanges heat with the lubricating oil that has absorbed the residual heat of the gas turbine 1043, the nitrogen gas that has absorbed the heat and has been vaporized flows out from the liquid nitrogen outlet of the first heat exchanger 102, and the lubricating oil that has been reduced in temperature flows out from the oil outlet of the first heat exchanger 102 and returns to the oil tank 103 through the oil inlet line 107. Meanwhile, the lubricating oil directly returns to the oil tank 103 through the oil input pipeline 107 after absorbing the waste heat of the generator 1041, and the lubricating oil directly returns to the oil tank 103 through the oil input pipeline 107 after absorbing the waste heat of the reducer 1042. That is, in the first heat exchanger 102, the recovered waste heat of the gas turbine 1043 is used to heat the liquid nitrogen.

Of course, the liquid nitrogen may be heated not only by the waste heat of any one of the generator 1041, the reducer 1042, and the gas turbine 1043, but also by the waste heat of any two of the generator 1041, the reducer 11042, and the gas turbine 1043. In a more preferable mode, the lubricant outlet of the generator 1041, the lubricant outlet of the reducer 1042, and the lubricant outlet of the gas turbine 1043 are all communicated with the oil inlet of the first heat exchanger 102, and the oil outlet of the first heat exchanger 102 is communicated with the inlet of the oil input pipeline 107, as shown in fig. 2. In the first heat exchanger 102, the liquid nitrogen exchanges heat with the lubricating oil absorbing the waste heat of the generator 1041, the waste heat of the reducer 1042 and the waste heat of the gas turbine 1043, the nitrogen gas absorbing the heat gasification flows out from the liquid nitrogen outlet of the first heat exchanger 102, and the lubricating oil with the reduced temperature flows out from the oil outlet of the first heat exchanger 102 and returns to the oil tank 103 through the oil input pipeline 107. That is, in the first heat exchanger 102, the recovered waste heat of the generator 1041, the reducer 1042, and the gas turbine 1043 is used to heat the liquid nitrogen.

It can be understood that, by the waste heat recovery apparatus 10 provided in the embodiment of the present application, the lubricating oil can absorb the waste heat of the generator 1041, the reducer 1042 and the gas turbine 1043, and transmit at least part of the absorbed waste heat to the liquid nitrogen through the first heat exchanger 102 to heat the liquid nitrogen, for example, the absorbed waste heat of at least one of the generator 1041, the reducer 1042 and the gas turbine 1043 can be transmitted to the liquid nitrogen, so that the liquid nitrogen can be gasified by using the recovered waste heat, and the use of fuel energy is saved.

On the other hand, in order to prevent overheating of the components of the generator 1041, the reducer 1042 and the gas turbine 1043, the lubricating oil input to the generator 1041, the reducer 1042 and the gas turbine 1043 needs to be able to take away the waste heat therefrom, that is, the temperature of the lubricating oil input to the generator 1041, the reducer 1042 and the gas turbine 1043 is low, and the lubricating oil input to the generator 1041, the reducer 1042 and the gas turbine 1043 is circulated by the lubricating oil (which has absorbed the waste heat and has a high temperature) flowing out from the generator 1041, the reducer 1042 and the gas turbine 1043, and therefore, the lubricating oil flowing out from the generator 1041, the reducer 1042 and the gas turbine 1043 needs to be cooled. Through the scheme that this application embodiment provided, the liquid nitrogen utilizes the waste heat of lubricating oil recovery to gasify the time, also can provide cold energy for lubricating oil, makes its cooling, need not additionally set up heat-dissipating equipment (if set up air cooling or water-cooled radiator etc.) to can effective saving equipment resource and cost.

In practical applications, if the air temperature is higher and the air density is reduced accordingly, the mass flow of air to the gas turbine 1043 is reduced accordingly, resulting in a reduction in the output power of the gas turbine 1043. Therefore, in one implementation, the waste heat recovery apparatus 10 provided by the embodiment of the present application further includes a second heat exchanger 108, a gas turbine intake line 109, and a second liquid nitrogen conveying line 110; as shown in fig. 6, the second heat exchanger 108 has a liquid nitrogen inlet, a liquid nitrogen outlet, an air inlet, and an air outlet; an outlet of the liquid nitrogen storage tank 101 is communicated with a liquid nitrogen inlet of the second heat exchanger 108 through the second liquid nitrogen conveying pipeline 110; the air outlet of the second heat exchanger 108 communicates with the air inlet of the gas turbine 1043 via the gas turbine inlet line 109.

The second heat exchanger 108 may be configured to exchange heat between air and liquid nitrogen, specifically, the heat exchange process may be that the air enters the second heat exchanger 108 from an air inlet of the second heat exchanger 108, and the liquid nitrogen enters the second heat exchanger 108 from a liquid nitrogen inlet of the second heat exchanger; temperature difference exists between the air and the liquid nitrogen, and in the second heat exchanger 108, the liquid nitrogen absorbs heat and is gasified into nitrogen gas and then flows out of a liquid nitrogen outlet of the second heat exchanger 108; the temperature of the air is reduced after transferring heat to the liquid nitrogen, and the reduced temperature air flows out from the air outlet of the second heat exchanger 108 and then enters the gas turbine 1043 through the gas turbine inlet line 109.

It can be understood that, by the above scheme, the liquid nitrogen exchanges heat with the air to be introduced into the gas turbine 1043, the temperature of the air to be introduced into the gas turbine 1043 can be reduced by using the cold energy of the liquid nitrogen, and the output power of the gas turbine 1043 can be further improved. On the other hand, liquid nitrogen can also absorb the heat of air to be gasified.

It is considered that if the temperature of the air cooled by the liquid nitrogen is too low, the air may be condensed and frozen after entering the gas turbine 1043, thereby causing damage to the gas turbine blade. Therefore, in one implementation, the waste heat recovery apparatus 10 provided by the embodiment of the present application further includes a first temperature sensor 111 and a first valve 112; as shown in fig. 7, the first temperature sensor 111 is located at the air outlet of the second heat exchanger 108, and the first valve 112 is disposed at the first position a of the second liquid nitrogen delivery pipe 110.

The first temperature sensor 111 may detect the temperature of the air cooled by the liquid nitrogen in real time.

A first valve 112 may control the flow of liquid nitrogen to the second heat exchanger 108, and the first valve 112 may be specifically a proportional valve.

It can be understood that, by the above-mentioned scheme, the opening degree of the first valve 112 can be controlled according to the temperature of the air cooled by the liquid nitrogen, which is detected by the first temperature sensor 111, so as to adjust the flow rate of the liquid nitrogen introduced into the second heat exchanger 108, so that the temperature of the air cooled by the liquid nitrogen can be within a target temperature range (for example, the target temperature range can be greater than or equal to 5 ℃), and thus, the air can be prevented from being too low in temperature, condensing and freezing after entering the gas turbine 1043, and causing damage to the gas turbine blades. Further, the waste heat recovery device 10 provided in the embodiment of the present application may further include a controller, where the controller is connected to the first temperature sensor 111 and the first valve 112, and is configured to automatically and timely control an opening of the first valve 112 according to the temperature of the air cooled by the liquid nitrogen and detected by the first temperature sensor 111.

In practical application, in order to reduce the noise of the gas turbine generator set, a box body made of a sound insulation material is generally arranged outside the gas turbine generator set, however, the gas turbine generator set can generate certain heat during working, the heat is accumulated in the box body to cause the temperature in the box body to rise, and the gas turbine generator set is easily damaged due to overhigh temperature in the box body. In the related art, a ventilation opening is generally formed in the box body, and air is sent into the box body through the ventilation opening by using a fan so as to take away heat in the box body. If the air temperature is higher, more air needs to be let into the box, which results in the fan needing to consume more electric power. Therefore, in one implementation, the waste heat recovery apparatus 10 provided by the embodiment of the present application further includes a tank 113 having a ventilation opening 1131, a third heat exchanger 114, a tank air inlet line 115, and a third liquid nitrogen conveying line 116; as shown in fig. 8, the generator 1041, the reducer 1042 and the gas turbine 1043 are disposed inside the casing 113; the third heat exchanger 114 has a liquid nitrogen inlet, a liquid nitrogen outlet, an air inlet and an air outlet; an outlet of the liquid nitrogen storage tank 101 is communicated with a liquid nitrogen inlet of the third heat exchanger 114 through the third liquid nitrogen conveying pipeline 116; the air outlet of the third heat exchanger 114 communicates with the vent 1131 of the tank 113 through the tank inlet duct 115.

The third heat exchanger 114 may be configured to exchange heat between air and liquid nitrogen, specifically, the heat exchange process may be that air enters the third heat exchanger 114 from an air inlet of the third heat exchanger 114, and liquid nitrogen enters the third heat exchanger 114 from a liquid nitrogen inlet of the third heat exchanger 114; temperature difference exists between the air and the liquid nitrogen, and in the third heat exchanger 114, the liquid nitrogen absorbs heat and is gasified into nitrogen gas and then flows out of a liquid nitrogen outlet of the third heat exchanger 114; the temperature of the air is reduced after the air transfers heat to the liquid nitrogen, and the air with the reduced temperature flows out from the air outlet of the third heat exchanger 114 and then enters the tank 113 through the tank inlet duct 115.

The casing 113 may further have a first opening, through which the gas turbine inlet line 109 may be connected to the gas turbine 1043, and the gas turbine inlet line 109 may be connected to an edge of the first opening in a sealing manner. The box 113 may also have a second opening therein, which may be used to carry air into the box 113 out of the box 113 so that the air may carry heat out of the box 113.

It can be understood that, through the above scheme, the liquid nitrogen and the air about to be introduced into the box body 113 are subjected to heat exchange, the temperature of the air about to be introduced into the box body 113 can be reduced by utilizing the cold energy of the liquid nitrogen, and then more air can be prevented from being introduced into the box body 113, so that more electric energy is prevented from being consumed. On the other hand, liquid nitrogen can also absorb the heat of air to be gasified.

Further, in order to smoothly introduce air into the box 113, in an embodiment, the waste heat recovery apparatus 10 provided in the embodiment of the present application further includes a fan 117; the blower 117 is disposed at an air inlet of the third heat exchanger 114, as shown in fig. 9-1; alternatively, the fan 117 is disposed at the vent 1131 of the case 113, as shown in fig. 9-2.

The electric power required by the fan 117 may be provided by a generator 1041.

It can be understood that, by the above-mentioned solution, the fan is arranged at the air inlet of the third heat exchanger 114 or the ventilation opening 1131 of the box 113, which can provide power for sucking air into the third heat exchanger 114 and then delivering the air into the box 113, so as to smoothly introduce air into the box 113.

In order to further recover more waste heat to gasify liquid nitrogen, in one embodiment, the waste heat recovery apparatus 10 provided in the embodiment of the present application further includes a fourth heat exchanger 118, a tail gas output pipeline 119, and a fourth liquid nitrogen conveying pipeline 120; as shown in fig. 10, the fourth heat exchanger 118 has a liquid nitrogen inlet, a liquid nitrogen outlet, a tail gas inlet, and a tail gas outlet; an outlet of the liquid nitrogen storage tank 101 is communicated with a liquid nitrogen inlet of the fourth heat exchanger 118 through the fourth liquid nitrogen conveying pipeline 120; the tail gas outlet of the gas turbine 1043 is communicated with the tail gas inlet of the fourth heat exchanger 118 through the tail gas output pipeline 119.

The tail gas generated after the gas turbine 1043 performs work contains a large amount of heat, the fourth heat exchanger 118 may be configured to exchange heat between the tail gas of the gas turbine 1043 and liquid nitrogen, specifically, the heat exchange process may be that the tail gas enters the fourth heat exchanger 118 from a tail gas inlet of the fourth heat exchanger 118, and the liquid nitrogen enters the fourth heat exchanger 118 from a liquid nitrogen inlet of the fourth heat exchanger 118; temperature difference exists between the tail gas and the liquid nitrogen, and in the fourth heat exchanger 118, the liquid nitrogen absorbs heat and is gasified into nitrogen gas and then flows out of a liquid nitrogen outlet of the fourth heat exchanger 118; the temperature of the tail gas is reduced after the heat is transferred to the liquid nitrogen, and the tail gas with the reduced temperature flows out from the tail gas outlet of the fourth heat exchanger 118 to be discharged. In practical applications, the exhaust gas of the gas turbine 1043 may also be subjected to a first heat recovery by the exhaust heat boiler, and then flows into the fourth heat exchanger 118 from the exhaust heat boiler through the exhaust gas output pipeline 119 to perform a second heat recovery.

The box 113 may further have a third opening, through which the exhaust gas output pipe 119 may be connected to the fourth heat exchanger 118, and the exhaust gas output pipe 119 may be connected to an edge of the third opening in a sealing manner. The third opening and the second opening may be different openings, i.e., the exhaust gas and the air introduced into the tank 113 may be discharged out of the tank 113 through different openings.

It can be understood that, through the above scheme, heat exchange is carried out between the liquid nitrogen and the tail gas of the gas turbine 1043 containing a large amount of heat, a large amount of waste heat can be recovered to gasify the liquid nitrogen, and the efficiency of gasifying the liquid nitrogen is improved.

In the field of oil and gas exploitation, in order to maintain the fracturing operation to be smoothly performed, the temperature of the nitrogen obtained by gasification cannot be too high (for example, cannot exceed a preset temperature, which can be set according to the actual fracturing operation requirement, for example, the value range of the preset temperature is 15-20 ℃). If the flow rate of the tail gas introduced into the fourth heat exchanger 118 is large and the tail gas contains a large amount of heat, the temperature of the nitrogen gas obtained by gasification in the fourth heat exchanger 118 may exceed a predetermined temperature. Therefore, in one implementation, the waste heat recovery apparatus 10 provided by the embodiment of the present application further includes an exhaust gas output branch 121 and a second valve 122; as shown in fig. 11, the inlet of the exhaust gas outlet branch 121 is communicated with the second position B of the exhaust gas outlet line 119 through the second valve 122.

The second valve 122 can control to introduce part of the tail gas into the tail gas output branch 121, and can further control the flow rate of the tail gas introduced into the tail gas output branch 121, so as to adjust the flow rate of the tail gas input from the tail gas output pipeline 119 to the fourth heat exchanger 118. The second valve 122 may be a three-way valve, a proportional valve. The outlet end of the tail gas output branch 121 may also be provided with an exhaust silencer.

It can be understood that, through the above scheme, the tail gas output branch 121 and the second valve 122 are provided, and the flow of the tail gas introduced into the fourth heat exchanger 118 can be adjusted by controlling the opening degree of the second valve 122, so that the temperature of the gasified liquid nitrogen is not too high, and the requirement of the fracturing operation is met.

Further, in order to accurately adjust the flow rate of the exhaust gas flowing into the fourth heat exchanger 118, in an embodiment, the waste heat recovery device 10 provided by the embodiment of the present application further includes a second temperature sensor 123; as shown in fig. 12, the second temperature sensor 123 is provided at the liquid nitrogen outlet of the fourth heat exchanger 118.

The second temperature sensor 123 may detect the temperature of the gasified liquid nitrogen in real time.

It can be understood that, by the above solution, the second valve 122 can be controlled according to the temperature of the nitrogen gas detected by the second temperature sensor 123 at the liquid nitrogen outlet of the fourth heat exchanger 118, so as to realize the precise adjustment of the flow rate of the tail gas to the fourth heat exchanger 118. Further, the second valve 122 and the second temperature sensor 123 may be respectively connected to the controller, and the controller may automatically and timely control the second valve 122 according to the temperature of the nitrogen gas detected by the second temperature sensor 123.

In practical applications, there may be situations where the liquid nitrogen entering the first heat exchanger 102, the second heat exchanger 108, the third heat exchanger 114 or the fourth heat exchanger 118 is not completely vaporized, i.e., there may be a mixture of liquid nitrogen and nitrogen gas flowing out of the liquid nitrogen outlet of the heat exchangers, and the mixture cannot meet the requirements of the fracturing operation. Therefore, in one implementation, the waste heat recovery apparatus 10 provided in the embodiment of the present application further includes a liquid nitrogen inflow line 124 and a separation device 125; as shown in fig. 13, the liquid nitrogen outlet of the first heat exchanger 102, the liquid nitrogen outlet of the second heat exchanger 108, the liquid nitrogen outlet of the third heat exchanger 114, and the liquid nitrogen outlet of the fourth heat exchanger 118 are all communicated with the inlet of the liquid nitrogen merging pipeline 124, and the outlet of the liquid nitrogen merging pipeline 124 is communicated with the inlet of the separation device 125.

Wherein liquid nitrogen inlet line 124 can be used to receive nitrogen gas, liquid nitrogen, or a mixture of liquid nitrogen and nitrogen gas from first heat exchanger 102, second heat exchanger 108, third heat exchanger 114, and fourth heat exchanger 118. The nitrogen gas, the liquid nitrogen or the mixture of the liquid nitrogen and the nitrogen gas flowing out of the liquid nitrogen outlet of the first heat exchanger 102, the liquid nitrogen outlet of the second heat exchanger 108, the liquid nitrogen outlet of the third heat exchanger 114 and the liquid nitrogen outlet of the fourth heat exchanger 118 are collected into a mixture of the liquid nitrogen and the nitrogen gas in a liquid nitrogen collecting pipeline 124.

The separation device 125 may be used to process the mixture of liquid nitrogen and nitrogen gas collected in the liquid nitrogen inlet line 124 to separate the liquid nitrogen from the nitrogen gas. The separation device 125 may specifically be a gas-liquid separator.

It can be understood that through the scheme, the liquid nitrogen inflow pipeline 124 and the separation device 125 are arranged, so that the mixed liquid nitrogen in the nitrogen can be removed, and the nitrogen can meet the requirements of the fracturing operation.

In practical applications, the fracturing operation may also have certain requirements on the pressure of nitrogen. Therefore, in one implementation, the waste heat recovery apparatus 10 provided by the embodiment of the present application further includes a pressure regulating device 126; as shown in fig. 14, the pressure adjusting device 126 is connected to the separation device 125.

The pressure regulating device 126 may be configured to regulate the pressure of the nitrogen gas, and the pressure regulating device 126 may be specifically a booster pump. The voltage regulating device 126 may be powered by a generator 1041.

The separation device 125 may have a nitrogen outlet from which separated nitrogen flows and enters the pressure regulating device 126. The separation device 125 may also have a liquid nitrogen outlet from which separated liquid nitrogen flows out into the liquid nitrogen storage tank 101.

It can be understood that, through above-mentioned scheme, set up pressure regulating device 126, pressure regulating device 126 is connected with separator 125 for pressure regulating device 126 can further carry out pressure adjustment to the nitrogen gas that is separated by separator 125, thereby makes nitrogen gas can satisfy fracturing operation demand.

In order to smoothly convey liquid nitrogen from the liquid nitrogen storage tank 101 to the first heat exchanger 102, the second heat exchanger 108, the third heat exchanger 114 and the fourth heat exchanger 118 for heat exchange, in an embodiment, the waste heat recovery apparatus 10 provided by the embodiment of the present application further includes a conveying pump 127; as shown in fig. 15, an outlet of the liquid nitrogen storage tank 101 communicates with an inlet of the transfer pump 127, and an outlet of the transfer pump 127 communicates with an inlet of the first liquid nitrogen transfer line 105, an inlet of the second liquid nitrogen transfer line 110, an inlet of the third liquid nitrogen transfer line 116, and an inlet of the fourth liquid nitrogen transfer line 120, respectively.

Wherein, the transfer pump 127 can provide power for transferring the liquid nitrogen from the liquid nitrogen storage tank 101 to the first heat exchanger 102, the second heat exchanger 108, the third heat exchanger 114 and the fourth heat exchanger 118. The transfer pump 127 may be powered by a generator 1041.

It can be understood that, by adopting the above scheme, the transfer pump 127 is arranged, so that the liquid nitrogen can be smoothly transferred from the liquid nitrogen storage tank 101 to the first heat exchanger 102, the second heat exchanger 108, the third heat exchanger 114 and the fourth heat exchanger 118 for heat exchange.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention in its corresponding aspects.

Claims

1. The waste heat recovery device is characterized by comprising a liquid nitrogen storage tank, a first heat exchanger, an oil tank, a power assembly, a first liquid nitrogen conveying pipeline, an oil output pipeline and an oil input pipeline;

2. The waste heat recovery apparatus of claim 1, wherein the power assembly includes a generator, a reducer, and a gas turbine, and the oil tank is a lubricating oil tank;

3. The heat recovery apparatus of claim 2, further comprising a second heat exchanger, a gas turbine inlet line, and a second liquid nitrogen delivery line;

4. The heat recovery device of claim 3, further comprising a first temperature sensor and a first valve;

5. The waste heat recovery apparatus of claim 3, further comprising a tank having a vent, a third heat exchanger, a tank inlet line, and a third liquid nitrogen delivery line;

6. The waste heat recovery device according to claim 5, further comprising a fourth heat exchanger, a tail gas output pipeline and a fourth liquid nitrogen conveying pipeline;

7. The heat recovery device of claim 6, further comprising a tail gas output branch and a second valve;

8. The heat recovery device of claim 7, further comprising a second temperature sensor;

9. The waste heat recovery apparatus according to claim 6, further comprising a liquid nitrogen inflow line and a separation device;

10. The heat recovery device of claim 6, further comprising a transfer pump;