Geothermal sewage waste heat solar energy coupling utilization device

Abstract

The invention discloses a geothermal sewage waste heat solar coupling utilization device which comprises a geothermal resource development system, a sewage waste heat exchange system, a solar reheating system, a heating furnace heat compensation system and a crude oil heating system. The water outlet end of the sewage waste heat exchange system is connected with the water inlet end of a plate heat exchanger of the solar reheating system through a circulating water pump, the water outlet end of the plate heat exchanger is connected with the water inlet end of a heating furnace heat compensation system or the water inlet end of a crude oil heating system, and the water outlet end of the heating furnace heat compensation system is connected with the water inlet end of the crude oil heating system. And the water outlet end of the crude oil heating system is connected back to the water inlet end of the geothermal resource development system. The device has the advantages of being high in sewage waste heat utilization rate, high in photothermal conversion efficiency, low in operation cost, high in automation degree, low in failure rate, safe, environmentally friendly, high in practical value and the like.

Description

Technical Field

[0001] The invention relates to a geothermal / waste heat from sewage / solar energy coupling utilization device, and in particular to a geothermal / waste heat from sewage / solar energy coupling utilization device based on a flat plate collector. Background Art

[0002] As a green, low-carbon, recyclable and renewable energy, geothermal energy has the characteristics of large reserves, wide distribution, clean and environmentally friendly, stable and reliable. However, due to the geological environment, there are few high-temperature geothermal resources suitable for exploitation in my country. The cost of high-temperature geothermal wells increases sharply with the increase of drilling depth, with large initial investment and high later operation and maintenance costs. Medium-temperature and low-temperature geothermal resources cannot directly reach the ideal temperature for oil field production, so they need to be heated by other means.

[0003] During crude oil extraction, a large amount of hot sewage is generated. If the waste heat of this sewage cannot be effectively utilized in the later sewage treatment process, it will cause a large energy loss. For example, a joint station receives 12,000 cubic meters of hot sewage every day, with an average temperature of 58.6℃. Most of this heat is released into the air or returned to the ground with sewage injection.

[0004] The joint station is a flammable and explosive place. It is not allowed to lay solar panels within 15 meters around oil and gas equipment, resulting in a large amount of high-quality solar energy resources being wasted. Taking a joint station as an example, the area available for laying solar panels in the station is only 6,300 square meters, of which about 11,300 square meters cannot be laid because the distance from the oil and gas equipment is less than 15 meters. Summary of the invention

[0005] The purpose of the present invention is to provide a geothermal sewage waste heat solar energy coupling utilization device, which combines geothermal technology, heat exchange technology and solar heating technology to achieve efficient and safe conversion of geothermal energy, sewage waste heat and solar energy.

[0006] To achieve the above-mentioned purpose, the technical solution of the present application is: a geothermal sewage waste heat and solar energy coupling utilization device, including a geothermal resource development system, a sewage waste heat exchange system, a solar energy reheating system, a heating furnace supplementary heat system, and a crude oil heating system. The water outlet of the geothermal resource development system is connected to the water inlet of the sewage waste heat exchange system, the water outlet of the sewage waste heat exchange system is connected to the water inlet of the plate heat exchanger of the solar energy reheating system through a circulating water pump, the water outlet of the plate heat exchanger is connected to the water inlet of the heating furnace supplementary heat system or the water inlet of the crude oil heating system, the water outlet of the heating furnace supplementary heat system is connected to the water inlet of the crude oil heating system, and the water outlet of the crude oil heating system is connected back to the water inlet of the geothermal resource development system.

[0007] Furthermore, the circulating water is heated for the first time by the geothermal resource development system, with the outlet water temperature at 38-42°C, and then the circulating water is heated for the second time by the sewage waste heat exchange system, with the temperature raised to 50-53°C; the heated hot water is pressurized by the circulating water pump and enters the plate heat exchanger of the solar energy reheating system, and after heat exchange with the medium of the plate heat exchanger, the temperature is raised to 65-68°C and then enters the crude oil heating system; the heating furnace supplementary heating system serves as a supplementary heat source for the solar energy reheating system, and automatically starts to heat the circulating water when there is insufficient light or no light; the circulating water heated to 65-68°C enters the crude oil heating system to heat the crude oil, and the heated circulating water flows into the geothermal resource development system again.

[0008] Furthermore, the solar energy reheating system includes a plate heat exchanger, a circulating water pump, and a flat plate collector, and the plate heat exchanger is connected to the flat plate collector via the circulating water pump.

[0009] Furthermore, a first automatic shut-off valve is provided between the solar energy reheating system and the heating furnace supplementary heat system, a second automatic shut-off valve is provided between the heating furnace supplementary heat system and the crude oil heating system, and a third automatic shut-off valve is provided between the solar energy reheating system and the crude oil heating system.

[0010] Furthermore, the solar reheating system has a built-in temperature sensor located at the outlet of the plate heat exchanger. When the medium temperature of the plate heat exchanger is lower than the required temperature, the valves at both ends of the plate heat exchanger are automatically closed; and the circulating water directly enters the heating furnace heating system.

[0011] Furthermore, the geothermal resource development system transforms idle and abandoned oil wells into geothermal wells. When the temperature inside the oil well is high, geothermal resources are directly extracted through casing heat exchange to increase the circulating water temperature; when the temperature inside the oil well is low, a water source heat pump is used to increase the circulating water temperature.

[0012] Furthermore, a tortuous heat exchange pipeline is installed inside the sewage tank of the sewage waste heat exchange system, and the sewage heat energy is transferred to the heat exchange pipeline by heat conduction. The heat exchange pipeline transfers the heat energy to the circulating water in the pipeline to increase the temperature of the circulating water.

[0013] Furthermore, the heating furnace supplementary heat system includes a heating furnace body, a temperature detector, and an intelligent burner. The intelligent burner is connected to the temperature detector and the heating furnace body. When the temperature detector detects that the circulating water temperature is lower than 65°, the intelligent burner starts working.

[0014] As a further step, the crude oil storage tank of the crude oil heating system is equipped with a tortuous heat exchange pipeline. The internal temperature of the crude oil storage tank is 28-32°C, and the liquid temperature of the medium in the heat exchange pipeline is 65-68°C. The heat energy of the heat exchange medium is transferred to the heat exchange pipeline through heat conduction, and the heat exchange pipeline then transfers the heat energy to the crude oil in the crude oil storage tank, thereby increasing the oil temperature in the storage tank.

[0015] As a further step, the circulating water entering the crude oil heating system heats the crude oil in the crude oil storage tank or heats the heat exchanger or heats the pipeline or heats the pipeline.

[0016] Due to the adoption of the above technical scheme, the present invention can achieve the following technical effects: this device can be used as an important supplement to geothermal resources, and the geothermal water source is heated for the first time by the waste heat of sewage, and the water source temperature is increased from 38-42℃ to 50-53℃; the geothermal water source is heated for the second time by solar energy, and the water source temperature is increased from 50-53℃ to 65-68℃. At the same time, considering the influence of light factors, a heating furnace is installed at the back end as a supplementary heat source. The comprehensive utilization of geothermal energy, waste heat from sewage, and solar energy is achieved; this device has the advantages of high waste heat utilization rate, high light-heat conversion efficiency, low operating cost, high degree of automation, low failure rate, safety and environmental protection, and high practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the structure of a device for coupling utilization of waste heat from geothermal sewage with solar energy;

[0018] Figure 2 This is a schematic diagram of the heat exchange principle of a water source heat pump;

[0019] Figure 3 This is a schematic diagram of the heat exchange pipeline in the sewage tank;

[0020] Explanation of the numbers in the figure: 1 - geothermal resource development system, 2 - wastewater waste heat exchange system, 3 - solar energy reheating system, 4 - heating furnace supplementary heat system, 5 - crude oil heating system. 301 - plate heat exchanger, 302 - circulating water pump, 303 - flat plate collector. DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0022] like Figure 1As shown, this embodiment provides a geothermal sewage waste heat solar energy coupling utilization device, a geothermal resource development system, a sewage waste heat heat exchange system 2, a solar energy reheating system 3, a heating furnace supplementary heat system 4, and a crude oil heating system 5;

[0023] Geothermal resource development system 1: Geothermal energy is an ancient energy source; it exists in rocks and fluids under the earth's crust. From the shallow ground to several kilometers or deeper below the surface, this energy can be brought to the surface by drilling to collect steam and high-temperature hot water for power generation, direct use, and heating and cooling. Oil and gas basins are rich in geothermal resources and have great potential for development and utilization. In the middle and late stages of oil field development, each oil field has many idle and abandoned oil and gas wells, which are distributed in different blocks of the oil field. Converting these oil and gas wells into geothermal wells can not only revitalize idle assets, but also provide heat sources for oil field crude oil dehydration, gathering and transportation heat tracing, and mining area heating and cooling. Conventional means of developing geothermal resources require a large investment, but by converting idle and abandoned oil wells into geothermal wells, it can not only reduce well drilling investment, but also revitalize oil field assets, which can be said to kill two birds with one stone.

[0024] Specifically, when the temperature inside the oil well is high, geothermal resources can be directly extracted through casing heat exchange. When the temperature inside the oil well is low, a water source heat pump can be used to further increase the circulating water temperature, such as Figure 2 As shown, the water source heat pump model can be R406A.

[0025] Wastewater heat exchange system 2: Figure 3 As shown, a tortuous heat exchange pipeline is installed inside the sewage tank. The internal temperature of the sewage tank is about 58.5°C. The heat energy of the sewage is transferred to the heat exchange pipeline through heat conduction, and the heat exchange pipeline transfers the heat energy to the circulating water in the pipeline to increase the temperature of the circulating water.

[0026] Solar reheating system 3: The solar reheating system includes a plate heat exchanger 301, a circulating water pump 302, and a flat plate collector 303; wherein the plate heat exchanger includes a group of corrugated metal plates with four corner holes for two heat transfer liquids to pass through. The metal plates are installed in a frame with a fixed plate and a movable clamping plate on the side and clamped with clamping bolts. Sealing gaskets are installed on the metal plates to seal the fluid channels and guide the fluids to flow alternately into their respective channels to form heat exchange.

[0027] Plate heat exchanger 301 has the following advantages:

[0028] ①High heat transfer coefficient.

[0029] The plate heat exchanger is composed of plates that are assembled inverted from each other. The corrugated shape of the plates forms a complex flow channel, which causes strong turbulence in the heat exchange medium, so the heat transfer coefficient is high.

[0030] ②Compact structure and small footprint.

[0031] The heat exchange area per unit volume can reach 250㎡.

[0032] ③The logarithmic mean temperature difference is large, and the terminal temperature difference is small.

[0033] Plate heat exchangers are mostly co-current or counter-current flow, and the logarithmic mean temperature difference correction coefficient is about 0.95. The flow of cold and hot fluids in the heat exchanger is parallel to the heat exchange surface, without bypass flow, the end temperature difference is small, and the water-to-water heat exchange can be less than 1°C.

[0034] ④Easy to change the heat exchange area or process combination.

[0035] If you want to increase or decrease the heat exchange area, you only need to add or reduce the plates; if you want to change the process combination, you only need to change the plate arrangement or replace a few plates to adapt to the new heat exchange conditions.

[0036] ⑤Low cost.

[0037] Plate heat exchangers are mainly made of metal plates, and the price of raw materials is lower than that of metal pipes.

[0038] ⑥Not easy to scale.

[0039] The fluid is greatly disturbed in the flow channel and dirt is not easy to deposit.

[0040] ⑦Easy to disassemble and clean

[0041] Just loosen the clamping bolts and move the movable end plate to remove the plate for cleaning. It is suitable for working conditions that require frequent cleaning and maintenance.

[0042] The circulating water pump 302 is mainly responsible for pressurizing the circulating water to form a forced water circulation. The circulating water pump in this device adopts a centrifugal pump. Advantages of centrifugal pumps:

[0043] ① The structure is simple and compact. For the same delivery volume, the centrifugal pump occupies a small area, is light in weight, consumes less material, and has higher foundation requirements than the double pump, so the manufacturing and installation costs are low.

[0044] ②It can run at high speed, and the transmission structure is simple and easy to install.

[0045] ③ Because of its simple structure, few parts, few failures, durability, low maintenance costs, easy management and reliable operation.

[0046] ④ The output volume can be adjusted arbitrarily or even fully closed by the discharge valve, and there will be no danger of unlimited increase in pressure head.

[0047] Flat plate collector 303:

[0048] It mainly includes several parts such as the heat absorbing plate, transparent cover plate, heat insulation layer, and shell. Sunlight shines through the transparent cover plate onto the heat absorbing plate coated with an absorption layer. Most of the solar radiation energy is absorbed by the heat absorbing plate, converted into heat energy, and transmitted to the working medium in the fluid channel. In this way, the cold working medium from the collector inlet is heated by solar energy in the fluid channel, and the temperature gradually increases. The heated hot working medium flows out from the collector outlet. Advantages of flat plate collector:

[0049] ① The core heat absorption part of the solar flat-plate collector adopts a whole heat absorption plate to form a partition inside the collector, limit heat convection, reduce heat loss, expand the heat absorption area, and the effect of heating hot water is more prominent.

[0050] ② The working fluid of the solar flat-plate collector and the system flows in the metal flow channel, so that it can operate under pressure, resist corrosion and prevent leakage.

[0051] ③ No scale is produced on the flat solar collector, which can maintain efficient heat collection for a long time without descaling and reducing maintenance.

[0052] ④The thermal efficiency of the flat-plate solar collector is high and the heat gain is the largest. The thermal efficiency of ordinary flat-plate solar collectors is generally higher than that of vacuum tube solar water heaters.

[0053] Heating furnace supplementary heat system 4: includes heating furnace body, temperature detector, intelligent burner, gas supply system, and the gas supply system is responsible for providing natural gas to the intelligent burner. The heating furnace body is a fire tube type heating furnace, including a cylinder, a pyrotechnic tube, a chimney, inlet and outlet pipes and a base, etc. The heated liquid enters the lower part of the furnace body through the inlet pipe and gradually fills the entire furnace body. The pyrotechnic tubes are immersed in the liquid. When the heating furnace is ignited, the heat is directly transferred to the heated liquid through the pyrotechnic tube. Under the effect of the specific gravity difference between the cold and hot liquids, the hot liquid floats up and flows out of the heating furnace from the outlet pipe to achieve the purpose of heating the liquid. The furnace body is always under pressure during the entire heating process. The fire tube type heating furnace has the following advantages:

[0054] ①High combustion efficiency

[0055] The fire tube heating furnace uses gas or liquid fuel as fuel, has high combustion efficiency, can heat quickly, and improves production efficiency.

[0056] ②Uniform heating

[0057] The design of the fire tube heating furnace ensures uniform heating, which can ensure the consistency of heating temperature and improve product quality.

[0058] ③Energy saving and environmental protection

[0059] The combustion system of the fire tube heating furnace is reasonably designed, which can maximize the use of fuel, reduce energy costs and reduce production costs. At the same time, the combustion system of the fire tube heating furnace adopts advanced combustion technology, which can reduce exhaust emissions and protect the environment.

[0060] ④Easy to operate

[0061] The fire tube heating furnace is easy to operate and maintain, and does not require professional technicians to operate and maintain it.

[0062] The temperature detector includes a thermocouple and a signal transmission line, which transmits the detected temperature signal to the intelligent burner. The intelligent burner automatically starts and stops and automatically adjusts the opening of the gas supply valve according to the detected temperature.

[0063] Crude oil heating system 5: A tortuous heat exchange pipeline is installed inside the crude oil storage tank. The internal temperature of the crude oil storage tank is 28-32°C, and the medium liquid temperature in the heat exchange pipeline is 65-68°C. The heat energy of the heat exchange medium is transferred to the heat exchange pipeline through heat conduction, and the heat exchange pipeline then transfers the heat energy to the crude oil in the crude oil storage tank to increase the oil temperature in the tank.

[0064] This device heats the circulating water for the first time through geothermal resources, and the outlet water temperature is about 38-42℃; the waste heat exchange system of sewage heats the circulating water for the second time, and the temperature is raised to 50-53℃; the heated hot water is pressurized by the circulating water pump and enters the plate heat exchanger 301 to exchange heat with the medium water heated by the 3 solar reheating system, and the temperature is raised to 65-68℃; the heating furnace supplementary heat system is used as a supplementary heat source for the solar reheating system, and automatically starts to heat the circulating water when the light resources are insufficient or there is no light; the circulating water heated to 65-68℃ enters the crude oil heating system to heat the crude oil. The solar reheating system has a built-in temperature sensor. When the medium temperature in the reheating system is lower than the required temperature, the valves at both ends are automatically closed, that is, the solar reheating system process is closed to prevent the heat loss of the water source. The crude oil heating system is not limited to the heating of crude oil in the storage tank, and can be heated by heat exchanger / pipeline heating / pipeline heating, etc.

[0065] The device has the advantages of high sewage waste heat utilization rate, high photothermal conversion efficiency, low operating cost, high degree of automation and low failure rate.

[0066] Take a joint station as an example:

[0067] The annual average temperature in the city is 10.5℃, and the annual solar irradiance per unit area is 5200MJ / m 2 a (Annual solar irradiance refers to the radiation energy received per unit area on the earth's surface each year after the solar radiation is absorbed, scattered and reflected by the atmosphere). The average thermal efficiency of the flat plate collector is 85% and the lighting area is 1000m 2, pipeline and heat exchanger heat loss 5%. Heating furnace thermal efficiency 52%, natural gas calorific value 36MJ / m 3 .

[0068] Solar heat exchanger generates heat energy per year:

[0069] Annual heat energy generated: 5200×106×1000×85%×(1-5%)=4.199×1012J

[0070] =4.199×106MJ

[0071] About 2-3 times of thermal energy can be extracted from the waste heat of sewage. Calculated at 2 times of thermal energy, 8.398×106MJ of thermal energy can be extracted.

[0072] Natural gas can be saved annually (4.199×106+8.398×106)÷52%÷36=67.3×104m 3 .

[0073] Saving one cubic meter of natural gas can reduce 1.96 kg of carbon dioxide emissions, and the total reduction in carbon dioxide emissions is:

[0074] 67.3×104×1.96=1318917 kg

[0075] ≈1319 tons

[0076] The cost of one cubic meter of gas is 3.3 yuan, which can save gas costs:

[0077] 67.3×104×3.3=2.22 million yuan.

[0078] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0079] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A geothermal sewage waste heat solar coupling utilization device, characterized in that: It includes a geothermal resource development system, a sewage waste heat exchange system, a solar energy reheating system, a heating furnace supplementary heat system, and a crude oil heating system. The water outlet of the geothermal resource development system is connected to the water inlet of the sewage waste heat exchange system. The water outlet of the sewage waste heat exchange system is connected to the water inlet of the plate heat exchanger of the solar energy reheating system through a circulating water pump. The water outlet of the plate heat exchanger is connected to the water inlet of the heating furnace supplementary heat system or the water inlet of the crude oil heating system. The water outlet of the heating furnace supplementary heat system is connected to the water inlet of the crude oil heating system. The water outlet of the crude oil heating system is connected back to the water inlet of the geothermal resource development system.

2. According to claim 1, a geothermal sewage waste heat solar coupling utilization device is characterized in that: The circulating water is heated for the first time by the geothermal resource development system, with the outlet water temperature at 38-42°C, and then the circulating water is heated for the second time by the sewage waste heat exchange system, with the temperature raised to 50-53°C; the heated hot water is pressurized by the circulating water pump and enters the plate heat exchanger of the solar reheating system, and after heat exchange with the medium of the plate heat exchanger, the temperature is raised to 65-68°C and then enters the crude oil heating system; the heating furnace supplementary heating system serves as a supplementary heat source for the solar reheating system, and automatically starts to heat the circulating water when there is insufficient light or no light; the circulating water heated to 65-68°C enters the crude oil heating system to heat the crude oil, and the heated circulating water flows into the geothermal resource development system again.

3. According to claim 1, a geothermal sewage waste heat solar coupling utilization device is characterized in that: The solar energy reheating system comprises a plate heat exchanger, a circulating water pump and a flat plate heat collector, wherein the plate heat exchanger is connected to the flat plate heat collector via the circulating water pump.

4. According to claim 1, a geothermal sewage waste heat solar coupling utilization device is characterized in that: A first automatic shut-off valve is provided between the solar energy reheating system and the heating furnace supplementary heat system, a second automatic shut-off valve is provided between the heating furnace supplementary heat system and the crude oil heating system, and a third automatic shut-off valve is provided between the solar energy reheating system and the crude oil heating system.

5. According to claim 3, a geothermal sewage waste heat solar coupling utilization device is characterized in that: The solar reheating system has a built-in temperature sensor located at the outlet of the plate heat exchanger. When the medium temperature of the plate heat exchanger is lower than the required temperature, the valves at both ends of the plate heat exchanger are automatically closed; the circulating water directly enters the heating furnace heating system.

6. The device for utilizing waste heat from geothermal sewage and solar energy by coupling according to claim 1, characterized in that: The geothermal resource development system transforms idle and abandoned oil wells into geothermal wells. When the temperature inside the oil well is high, geothermal resources are directly extracted through casing heat exchange to increase the circulating water temperature; when the temperature inside the oil well is low, a water source heat pump is used to increase the circulating water temperature.

7. The device for utilizing waste heat from geothermal sewage and solar energy coupling according to claim 1, characterized in that: The sewage tank of the sewage waste heat exchange system is equipped with a tortuous heat exchange pipeline, which transfers the heat energy of the sewage to the heat exchange pipeline through heat conduction, and the heat exchange pipeline transfers the heat energy to the circulating water in the pipeline to increase the temperature of the circulating water.

8. The device for utilizing waste heat from geothermal sewage and solar energy coupling according to claim 1, characterized in that: The heating furnace supplementary heat system includes a heating furnace body, a temperature detector, and an intelligent burner. The intelligent burner is connected to the temperature detector and the heating furnace body. When the temperature detector detects that the circulating water temperature is lower than 65°, the intelligent burner starts to work.

9. The device for utilizing waste heat from geothermal sewage and solar energy in coupling according to claim 1, characterized in that: The crude oil storage tank of the crude oil heating system is equipped with a tortuous heat exchange pipeline. The internal temperature of the crude oil storage tank is 28-32°C, and the medium liquid temperature in the heat exchange pipeline is 65-68°C. The heat energy of the heat exchange medium is transferred to the heat exchange pipeline through heat conduction, and the heat exchange pipeline then transfers the heat energy to the crude oil in the crude oil storage tank, thereby increasing the oil temperature in the storage tank.

10. The device for utilizing waste heat from geothermal sewage and solar energy coupling according to claim 1, characterized in that: The circulating water entering the crude oil heating system heats the crude oil in the crude oil storage tank or heats the heat exchanger or pipeline or pipeline tracing.

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