A low-grade waste heat recovery and utilization system for a gas power unit

Abstract

The present invention provides a low-grade waste heat recovery and utilization system for a gas-powered unit, which includes a hot blast stove. The hot blast stove includes a burner and a furnace chamber. The air inlet of the burner is connected with a combustion-supporting hot air input component that utilizes the radiant heat of the gas-powered unit, and the air inlet of the furnace chamber is connected with a flue gas input pipe, and the flue gas input pipe is connected with the smoke exhaust port of the gas-powered unit. The present invention converts various forms of waste heat of the gas-powered unit into a single form of heat for recovery and utilization, unifies the utilization ways of various waste heat forms, makes the waste heat utilization more convenient, has a higher waste heat utilization rate, and is more energy-saving and environment-friendly.

Description

Technical Field

[0001] The present invention relates to the technical field of natural distributed energy and waste heat recovery and utilization. Specifically, it relates to a low-grade waste heat recovery and utilization system for gas-powered units. Background Art

[0002] In a natural gas distributed energy station, the main equipment is a gas-powered unit. The gas-powered unit mainly includes two types, one is a gas turbine, and the other is a gas internal combustion engine. From the energy balance of the gas turbine, the output effective power generally accounts for about 33% of the total heat of fuel combustion, the flue gas heat accounts for about 50% of the total heat of fuel combustion, and the remaining about 17% of the energy is lost in the form of air radiation from the heat dissipation port. From the energy balance of the gas internal combustion engine, the output effective power generally accounts for 40% of the total heat of fuel combustion, the flue gas heat accounts for about 24% of the total heat of fuel combustion, the heat radiation energy carried away by the engine cooling jacket water is about 20%, and the remaining about 16% of the energy is lost in the form of air radiation from the heat dissipation port.

[0003] It can be seen that for both the gas turbine and the gas internal combustion engine, the low-grade waste heat is in two forms: flue gas and radiation heat (where the radiation heat of the gas turbine is mainly dissipated in the form of air radiation, and the radiation heat of the gas internal combustion engine is mainly dissipated in the form of cylinder jacket water cooling + air radiation). The proportion of low-grade waste heat is relatively large. In actual applications, the waste heat in these two forms often adopts different utilization methods and is applied in different scenarios (for example, in the traditional method, the flue gas waste heat can generally be used for heating, and the cylinder jacket water can generally be used as the driving heat source for a heat pump). The waste heat utilization is rather troublesome, and problems such as long-distance energy transmission losses are involved, and the effective utilization rate of waste heat is also relatively low. Summary of the Invention

[0004] The purpose of the present invention is to provide a low-grade waste heat recovery and utilization system for gas-powered units, which converts various forms of waste heat of the gas-powered unit into a single form of heat for recovery and utilization, unifies the utilization methods of various waste heat forms, makes waste heat utilization more convenient, has a higher waste heat utilization rate, and is more energy-saving and environmentally friendly.

[0005] The embodiments of the present invention are realized through the following technical solutions:

[0006] A low-grade waste heat recovery and utilization system for a gas-powered unit includes a hot blast stove. The hot blast stove includes a burner and a furnace chamber. The air inlet of the burner is connected to a combustion-supporting hot air input component that utilizes the radiation heat of the gas-powered unit, and the air inlet of the furnace chamber is connected to a flue gas input pipe, and the flue gas input pipe is connected to the smoke exhaust port of the gas-powered unit.

[0007] Optionally, the combustion-supporting hot air input component includes a combustion-supporting hot air input pipe, and the combustion-supporting hot air input pipe is connected to the heat dissipation port of the gas-powered unit.

[0008] Optionally, the combustion-supporting hot air input component includes a combustion-supporting hot air input pipe that communicates with the outside air. A heat exchange pipe is provided in the combustion-supporting hot air input pipe, and the heat exchange pipe is connected to the jacket water outlet of the gas power unit.

[0009] Optionally, the combustion-supporting hot air input component includes at least two combustion-supporting hot air input pipes. One of the combustion-supporting hot air input pipes is connected to the heat dissipation port of the gas power unit, and the other combustion-supporting hot air input pipe communicates with the outside air and is provided with a heat exchange pipe inside. The heat exchange pipe is connected to the jacket water outlet of the gas power unit.

[0010] Optionally, the heat exchange pipe is a serpentine coiled pipe.

[0011] Optionally, a first blower is provided at the inlet of the combustion-supporting hot air input pipe that communicates with the outside air.

[0012] Optionally, there are multiple combustion-supporting hot air input pipes and multiple flue gas input pipes.

[0013] Optionally, a normal-temperature air input pipe is further connected to the air inlet of the burner.

[0014] Optionally, a regulating damper is provided at the inlet of the normal-temperature air input pipe.

[0015] Optionally, a second blower is provided at the inlet of the normal-temperature air input pipe.

[0016] The present invention has at least the following advantages and beneficial effects:

[0017] 1. In the present invention, the combustion-supporting hot air input component can utilize the radiant heat of the gas power unit to input combustion-supporting hot air to the burner. When the burner burns to produce a hot flame of the same temperature, compared with inputting the same amount of normal-temperature combustion-supporting air, the amount of fuel used by the burner can be reduced.

[0018] 2. In the present invention, after the radiant heat of the gas power unit is input to the burner for combustion support in the form of hot air, the high-temperature hot flame generated by the burner's combustion is mixed and heat-exchanged with the flue gas discharged from the gas power unit in the hot blast stove. Finally, the temperature of the hot air output by the hot blast stove can be controlled between the flue gas temperature and the hot flame temperature. In practical applications, the temperature of the hot air output by the hot blast stove can also be controlled by controlling the ratio of the flue gas to the hot flame.

[0019] 3. In the present invention, the radiant heat of the gas-powered unit is input into the burner for combustion assistance in the form of hot air. After that, the high-temperature hot flame generated by the combustion of the burner is mixed with the flue gas discharged from the gas-powered unit in the hot blast stove, converting the waste heat in two forms into a single form of heat for recovery and utilization. This unifies the utilization path of the waste heat form, making the waste heat utilization more convenient, with a higher waste heat utilization rate, and being more energy-saving and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other relevant drawings can also be obtained based on these drawings.

[0021] Figure 1 FIG. is a schematic structural diagram of a low-grade waste heat recovery and utilization system for a gas-powered unit provided for Embodiment 1;

[0022] Figure 2 FIG. is a schematic structural diagram of a low-grade waste heat recovery and utilization system for a gas-powered unit provided for Embodiment 2;

[0023] Figure 3 FIG. is a schematic structural diagram of a low-grade waste heat recovery and utilization system for a gas-powered unit provided for Embodiment 3;

[0024] Figure 4 FIG. is a schematic structural diagram of a low-grade waste heat recovery and utilization system for a gas-powered unit provided for Embodiment 4;

[0025] Reference numerals: 1 - hot blast stove, 101 - burner, 102 - furnace chamber, 2 - combustion-assisting hot air input component, 201 - combustion-assisting hot air input pipe, 202 - heat exchange pipe, 203 - first blower, 3 - flue gas input pipe, 4 - normal-temperature air input pipe, 5 - regulating air damper, 6 - second blower. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] Embodiment 1

[0027] Please refer to Figure 1 , a low-grade waste heat recovery and utilization system for a gas-powered unit, including a hot blast stove 1. The hot blast stove 1 is a prior art. Generally, the hot blast stove 1 includes a burner 101 and a furnace chamber 102. Its working principle is that the nozzle of the burner 101 extends into the furnace chamber 102, and the hot flame generated by the combustion of the burner 101 exchanges heat with the air entering the furnace chamber 102, and finally the hot air is output from the air outlet of the furnace chamber 102.

[0028] The present invention combines a hot blast stove 1 with the waste heat utilization of a gas power unit. Specifically, an air inlet of a burner 101 is connected to a combustion-supporting hot air input component 2 that utilizes the radiant heat of the gas power unit, and an air inlet of a furnace chamber 102 is connected to a flue gas input pipe 3, and the flue gas input pipe 3 is connected to an exhaust port of the gas power unit.

[0029] In this embodiment, the combustion-supporting hot air input component 2 includes a combustion-supporting hot air input pipe 201, and the combustion-supporting hot air input pipe 201 is connected to a heat dissipation port of the gas power unit. On this basis, this embodiment is mainly applied to an energy distribution station where the gas power unit is mainly a gas turbine (the radiant heat of the gas turbine is mainly dissipated in the form of air radiation). Since the gas turbine is generally arranged inside a casing and there is a heat dissipation port on the casing, in this embodiment, the combustion-supporting hot air input pipe 201 is connected through a pipeline to collect the heat dissipation of the gas turbine. Further, a fan can be used to blow air into the inside of the gas turbine casing, and the blown air is heated by the radiant heat of the gas turbine and finally enters the combustion-supporting hot air input pipe 201 from the heat dissipation port to support the combustion of the burner 101.

[0030] Furthermore, in this embodiment, both the combustion-supporting hot air input pipe 201 and the flue gas input pipe 3 are provided with a plurality of them, and the specific quantity can be determined according to the number of gas power units in the energy distribution station, so as to fully utilize the waste heat of the gas power units in the energy distribution station.

[0031] It should be noted that the combustion-supporting hot air input component 2 can utilize the radiant heat of the gas power unit to input combustion-supporting hot air to the burner 101. When the burner 101 burns to produce a hot flame of the same temperature, compared with inputting the same amount of normal-temperature combustion-supporting air, the use amount of fuel of the burner 101 can be reduced. The high-temperature hot flame generated by the combustion of the burner 101 is mixed and heat-exchanged with the flue gas discharged from the gas power unit in the furnace chamber 102. Finally, the hot air temperature output by the hot blast stove 1 can be controlled between the flue gas temperature and the hot flame temperature, and the hot air finally output by the hot blast stove 1 can be utilized according to actual needs. For example, the hot air finally output by the hot blast stove 1 can be used as a heat source for a drying device. In practical applications, the hot air temperature output by the hot blast stove 1 can also be controlled by controlling the input amount of flue gas. For example, a damper is arranged at the air inlet of the furnace chamber 102 to adjust the air intake.

[0032] In addition, after the radiant heat of the gas power unit of the present invention is input to support combustion in the form of hot air by the burner, the high-temperature hot flame generated by the combustion of the burner is mixed with the flue gas discharged from the gas power unit in the hot blast stove, converting the waste heat in two forms into a single form of heat for recovery and utilization, unifying the utilization path of the waste heat form, making the waste heat utilization more convenient, having a higher waste heat utilization rate, and being more energy-saving and environmentally friendly.

[0033] Embodiment 2

[0034] Please refer toFigure 2 , the difference between this embodiment and the first embodiment lies in the specific structure of the combustion-supporting hot air input component 2. In this embodiment, the combustion-supporting hot air input component 2 includes a combustion-supporting hot air input pipe 201, the combustion-supporting hot air input pipe 201 is connected to the outside air, and a heat exchange pipe 202 is arranged inside the combustion-supporting hot air input pipe 201, and the heat exchange pipe 202 is connected to the cylinder jacket water outlet of the gas power unit.

[0035] On this basis, this embodiment is mainly applied to an energy distribution station where the gas power unit is mainly a gas internal combustion engine (mainly dissipating heat in the form of cylinder jacket water cooling + air radiation, and the proportion of cylinder jacket water cooling for heat dissipation is relatively large). When in use, the cylinder jacket water of the gas internal combustion engine enters the heat exchange pipe 202, and the outside air enters the combustion-supporting hot air input pipe 201 to exchange heat with the cylinder jacket water, so that the air entering the combustion-supporting hot air input pipe 201 is heated, and the heated air enters the burner 101 to support combustion.

[0036] The heat exchange pipe 202 is a serpentine coiled pipe, that is, it is in a serpentine disk shape, which can increase the heat exchange area and improve the heat exchange efficiency. In addition, after the cylinder jacket water is heat-exchanged, it can enter the gas power unit again for cooling again and be recycled, or it can be collected for other uses.

[0037] In this embodiment, a first blower 203 is arranged at the inlet of the combustion-supporting hot air input pipe 201 connected to the outside air. The setting of the first blower 203 can adjust the air inlet speed and facilitate better combustion support for the burner 101.

[0038] Embodiment Three

[0039] Please refer to Figure 3 , this embodiment provides a structure of the combustion-supporting hot air input component 2 different from that in the first and second embodiments. The combustion-supporting hot air input component 2 in this embodiment includes at least two combustion-supporting hot air input pipes 201. One of the combustion-supporting hot air input pipes 201 is connected to the heat dissipation port of the gas power unit, and the other combustion-supporting hot air input pipe 201 is connected to the outside air and a heat exchange pipe 202 is arranged inside, and the heat exchange pipe 202 is connected to the cylinder jacket water outlet of the gas power unit.

[0040] On this basis, one application scenario of this embodiment can be an energy distribution station where the gas power unit is mainly a gas internal combustion engine. In this scenario, one of the combustion-supporting hot air input pipes 201 is connected to the heat dissipation port of the gas power unit. Similar to the embodiment, the waste heat existing in the form of air heat dissipation of the gas power unit is directly utilized. A heat exchange pipe 202 is arranged in the other combustion-supporting hot air input pipe 201. Similar to the second embodiment, the cylinder jacket water of the gas power unit enters the heat exchange pipe 202, and the outside air enters this combustion-supporting hot air input pipe 201 to exchange heat with the cylinder jacket water, so that the air entering the combustion-supporting hot air input pipe 201 is heated, and the heated air enters the burner 101 to support combustion.

[0041] The second application scenario of this embodiment can be an energy distribution station where the gas power unit is a combination of a gas internal combustion engine and a gas turbine. In this scenario, multiple combustion air input pipes 201 can be provided. Among them, the combustion air input pipe 201 provided with the heat exchange pipe 202 is connected to the outside air, and the jacket water of the gas internal combustion engine enters the heat exchange pipe 202 to heat the air. The combustion air input pipe 201 without the heat exchange pipe 202 is directly connected to the heat dissipation port of the gas turbine or the gas internal combustion engine.

[0042] It is easy to understand that the heat exchange pipe 202 in this embodiment can also be a serpentine coil pipe, that is, in a serpentine disk shape, which can increase the heat exchange area and improve the heat exchange efficiency. Similarly, after the jacket water is heat-exchanged, it can enter the gas power unit again for cooling and recycling, or it can be collected for other uses.

[0043] In addition, similar to Embodiment 2, a first blower 203 is also provided at the inlet of the combustion air input pipe 201 that is connected to the outside air in this embodiment. The setting of the first blower 203.

[0044] Embodiment 4

[0045] Please refer to Figure 4 , this embodiment is further optimized on the basis of Embodiment 1. A normal temperature air input pipe 4 is also connected to the air inlet of the burner 101 in this embodiment. The normal temperature air input pipe 4 is directly connected to the outside air. The air entering from the normal temperature air input pipe 4 can be mixed with the hot air input from the combustion air input pipe 201 to achieve the purpose of adjusting the temperature of the combustion air. Moreover, with such a setting, when the gas power unit is not working, the gas burner 101 can be assisted by the air inlet of the normal temperature air input pipe 4 to ensure that the burner 101 can also work normally when the power unit is not working. Further, an air inlet pipe connected to the outside air can also be provided at the air inlet of the furnace chamber 102 to ensure that the outside air can be input at the air inlet of the furnace chamber 102 when the gas power unit is not working.

[0046] Further, a regulating damper 5 is provided at the inlet of the normal temperature air input pipe 4 to facilitate controlling the air intake volume of the normal temperature air input pipe 4; a second blower 6 is provided at the inlet of the normal temperature air input pipe 4 to facilitate adjusting the air intake speed of the normal temperature air input pipe 4.

[0047] On this basis, those skilled in the art should know that this embodiment can also be further optimized on the basis of Embodiment 2 or Embodiment 3.

[0048] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A low-grade waste heat recovery and utilization system for a gas-powered unit, characterized in that: It includes a hot blast stove (1), and the hot blast stove (1) includes a burner (101) and a furnace chamber (102). An air inlet of the burner (101) is connected with a combustion-supporting hot air input component (2) that utilizes the radiant heat of a gas power unit, and an air inlet of the furnace chamber (102) is connected with a flue gas input pipe (3). The flue gas input pipe (3) is connected with the smoke exhaust port of the gas power unit; After the radiant heat of the gas power unit is input in the form of hot air for burner combustion support, the high-temperature hot flame generated by the burner combustion is mixed with the flue gas discharged from the gas power unit in the hot blast stove, so as to convert the waste heat in two forms into a single form of heat; The high-temperature hot flame generated by the burner combustion is mixed and heat-exchanged with the flue gas discharged from the gas power unit in the hot blast stove, and can control the hot air temperature output by the hot blast stove between the flue gas temperature and the hot flame temperature.

2. The low-grade waste heat recovery and utilization system of a gas power unit according to claim 1, characterized in that: The combustion-supporting hot air input component (2) includes a combustion-supporting hot air input pipe (201), and the combustion-supporting hot air input pipe (201) is connected with the heat dissipation port of the gas power unit.

3. The low-grade waste heat recovery and utilization system of a gas-powered unit according to claim 1, wherein: The combustion-supporting hot air input component (2) includes a combustion-supporting hot air input pipe (201), the combustion-supporting hot air input pipe (201) communicates with the outside air, and a heat exchange pipe (202) is arranged in the combustion-supporting hot air input pipe (201). The heat exchange pipe (202) is connected with the cylinder jacket water outlet of the gas power unit.

4. The low-grade waste heat recovery and utilization system of a gas power unit according to claim 1, characterized in that: The combustion-supporting hot air input component (2) includes at least two combustion-supporting hot air input pipes (201). One of the combustion-supporting hot air input pipes (201) is connected with the heat dissipation port of the gas power unit, and the other combustion-supporting hot air input pipe (201) communicates with the outside air and is internally provided with a heat exchange pipe (202). The heat exchange pipe (202) is connected with the cylinder jacket water outlet of the gas power unit.

5. The low-grade waste heat recovery and utilization system of a gas power unit according to claim 3 or 4, characterized in that: The heat exchange pipe (202) is a serpentine coil.

6. The low-grade waste heat recovery and utilization system for a gas power unit according to claim 3 or 4, characterized in that: A first blower (203) is arranged at the inlet of the combustion-supporting hot air input pipe (201) that communicates with the outside air.

7. The low-grade waste heat recovery and utilization system of a gas power unit according to any one of claims 2-4, characterized in that: A plurality of the combustion-supporting hot air input pipes (201) are provided, and a plurality of the flue gas input pipes (3) are also provided.

8. The low-grade waste heat recovery and utilization system for a gas-powered unit according to any one of claims 1 to 4, characterized in that: An air inlet of the burner (101) is further connected with a normal temperature air input pipe (4).

9. The low-grade waste heat recovery and utilization system of a gas power unit according to claim 8, characterized in that: An adjusting air damper (5) is arranged at the inlet of the normal temperature air input pipe (4).

10. The low-grade waste heat recovery and utilization system for a gas-powered unit according to claim 9, characterized in that: A second blower (6) is arranged at the inlet of the normal temperature air input pipe (4).

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