Steam supply system for energy comprehensive utilization

Abstract

This utility model belongs to the technical field of energy utilization, and specifically proposes a steam supply system for comprehensive energy utilization, including: an air source heat pump, a biomass boiler (8), a flash evaporation device (9), and a steam compressor. In this application, by coupling the air source heat pump with biomass, the ambient temperature feedwater can be heated by the air source heat pump and supplied to the biomass boiler (8). The biomass boiler (8) uses the heated water to prepare steam, which reduces energy consumption compared to directly heating the ambient temperature feedwater to prepare steam. When the biomass boiler (8) is not in use or lacks biomass fuel, the high temperature water prepared by the air source heat pump can be supplied to the flash evaporation device (9). The low temperature and low pressure steam prepared by the flash evaporation device (9) is pressurized and heated by the steam compressor and then transported to the external steam supply pipeline (23) to provide steam to users, which makes reasonable use of biomass fuel and meets the steam supply requirements.

Description

Technical Field

[0001] This application belongs to the technical field of energy utilization, and in particular relates to a steam supply system for comprehensive energy utilization. Background Technology

[0002] In areas with relatively abundant biomass, such as rural and mountainous regions, biomass boilers can be used to burn crop straw and branches to produce steam to meet daily heating needs. Air source heat pumps can also be used to produce hot water or hot air to meet daily heating requirements. However, the production and storage costs of biomass fuel give it a distinct seasonal characteristic; sometimes the supply of biomass fuel is low or the price is high, making biomass boilers unsuitable for all-weather operation. While air source heat pumps have a high energy conversion rate and low carbon emissions, due to technological and cost limitations, they can only raise the temperature of water within a certain range and are not suitable for direct steam production for daily use.

[0003] Therefore, how to couple air source heat pumps with biomass boilers and achieve steam supply while making reasonable use of biomass fuel has become a concern for technicians. Utility Model Content

[0004] Existing technologies present the challenge of how to couple air source heat pumps with biomass boilers to achieve steam supply while making rational use of biomass fuel.

[0005] To address the aforementioned technical problems, according to some embodiments, this application provides a steam supply system for comprehensive energy utilization, comprising:

[0006] An air source heat pump is used to heat the water supply using electricity and air energy, and its water supply inlet is connected to the water supply pipeline.

[0007] A biomass boiler, wherein its first water inlet is connected to the high-temperature water outlet of the air source heat pump, and its first steam outlet is connected to an external steam supply pipeline, is used to burn biomass fuel to produce steam from high-temperature water;

[0008] The flash evaporator has a second water inlet connected to the high-temperature water outlet of the air source heat pump for preparing steam and water using high-temperature water; the second water outlet of the flash evaporator is connected to the water supply inlet of the air source heat pump; and the second water inlet of the flash evaporator is connected to the water supply pipeline.

[0009] A steam compressor, the third steam inlet of which is connected to the second steam outlet of the flash evaporator, and the third steam outlet of which is connected to the external steam supply pipeline;

[0010] The steam compressors are connected in series, and the steam compressors are connected by a steam compression pipeline. The steam compression pipeline is provided with a cooling section, which is used to reduce the temperature of the steam flowing inside by using the water supply from the water supply pipeline.

[0011] Furthermore, the air source heat pump is a single unit or multiple units cascaded in series.

[0012] Furthermore, the air source heat pump consists of two cascaded units connected in series; wherein,

[0013] A first air source heat pump is formed by sequentially connecting a low-temperature evaporator, a low-temperature compressor, the heat release end of an overlapping heat exchanger, and a first throttling valve.

[0014] The heat absorption end of the overlapping heat exchanger, the high-temperature compressor, the high-temperature condenser, and the second throttle valve are sequentially and cyclically connected to form a second air source heat pump.

[0015] The water inlet of the high-temperature condenser is connected to the water supply pipeline, and the high-temperature water outlet of the high-temperature condenser is connected to the first water inlet of the biomass boiler and the second water inlet of the flash evaporator, respectively.

[0016] Furthermore, the second water outlet of the flash evaporator and the water inlet of the air source heat pump are equipped with a circulating water pump and a first valve.

[0017] Furthermore, the water supply pipeline is equipped with a water supply pump and a second valve;

[0018] The second water inlet of the flash evaporator is equipped with a third valve;

[0019] The biomass boiler is equipped with a fourth valve at its first water inlet.

[0020] Furthermore, a fifth valve is directly connected to the second water inlet and the water supply pipeline.

[0021] The above-mentioned technical solution of this utility model has at least the following beneficial technical effects:

[0022] This application utilizes an air-source heat pump coupled with biomass, enabling the use of air to heat ambient temperature feedwater for supply to a biomass boiler. The biomass boiler then uses this heated water to produce steam, reducing energy consumption and carbon emissions compared to directly heating ambient temperature feedwater in the biomass boiler. When the biomass boiler is shut down or its actual production capacity is reduced, the high-temperature water produced by the air-source heat pump can be supplied to a flash evaporator. The low-temperature, low-pressure steam produced by the flash evaporator is then pressurized and heated by a steam compressor and delivered to an external steam supply pipeline for steam users, thus making rational use of biomass fuel and ensuring steam supply. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application or in the conventional technology, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of a steam supply system for comprehensive energy utilization in one embodiment of this application.

[0025] in, Figure 1 The correspondence between the reference numerals and component names in the attached drawings is as follows:

[0026] 1. Low-temperature evaporator; 2. Low-temperature compressor; 3. Overlapping heat exchanger; 4. First throttle valve; 5. High-temperature compressor; 6. High-temperature condenser; 7. Second throttle valve; 8. Biomass boiler; 9. Flash evaporator; 10. Circulating water pump; 11. Feed water pump; 12. Flow valve; 13. First steam compressor; 14. Second steam compressor; 15. Third steam compressor; 16. First valve; 17. Second valve; 18. Third valve; 19. Fourth valve; 20. Fifth valve.

[0027] 21. Water supply pipeline; 22. Steam compression pipeline; 23. External steam supply pipeline.

[0028] 31. First water inlet; 32. First steam outlet; 33. Second water inlet one; 34. Second water inlet two; 35. Second steam outlet; 36. Second water outlet; 37. Third steam inlet; 38. Feed water inlet; 39. High-temperature water outlet. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the various embodiments of this application will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details are presented in the various embodiments of this application to facilitate a better understanding of the application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments. The division of the various embodiments below is for ease of description and should not constitute any limitation on the specific implementation of this application. The various embodiments can be combined with and referenced by each other without contradiction.

[0030] One embodiment of this application provides a steam supply system for comprehensive energy utilization, comprising:

[0031] An air source heat pump is used to heat the feedwater using electricity and air energy. Its feedwater inlet is connected to the feedwater pipeline 21. Existing air source heat pumps can convert ambient temperature feedwater into high temperature water of 80-90°C, which is used to supply biomass boiler 8.

[0032] It should be noted that, for ease of description, in this application, the names of the water and steam inlets and outlets on the biomass boiler 8 are prefixed with "first"; the water and steam inlets and outlets on the flash evaporator 9 are prefixed with "second"; the steam inlets and outlets on the steam compressor are prefixed with "third"; valves are not included in this naming convention.

[0033] The first water inlet 31 of the biomass boiler 8 is connected to the high-temperature water outlet 39 of the air source heat pump, and its first steam outlet 32 ​​is connected to the external steam supply pipeline 23 for burning biomass to produce steam from high-temperature water. Since the principle of the air source heat pump is to use electrical energy to transfer heat, while the biomass boiler 8 directly produces heat, the heat conversion rate of the air source heat pump is higher than that of the biomass boiler 8 or the electric boiler. Furthermore, the electrical energy of the air source heat pump may come from wind energy, solar energy, etc. Therefore, using the air source heat pump to heat the ambient temperature feedwater first saves energy and reduces carbon emissions compared to directly using the ambient temperature feedwater to produce steam in the biomass boiler 8.

[0034] The flash evaporator 9 has its second water inlet 33 connected to the high-temperature water outlet 39 of the air source heat pump for producing steam and water using high-temperature water. The second water outlet 37 of the flash evaporator 9 is connected to the feed water inlet 38 of the air source heat pump, and the second water inlet 34 of the flash evaporator 9 is connected to the feed water pipeline 21. When the biomass boiler 8 needs to be shut down or lacks biomass fuel, the system connects the air source heat pump to the flash evaporator 9. The flash evaporator 9 separates the high-temperature water into low-temperature, low-pressure saturated steam and low-temperature, low-pressure saturated water. The low-temperature, low-pressure saturated water is returned to the air source heat pump for recirculation to produce high-temperature water.

[0035] The steam compressor has its third steam inlet 37 connected to the second steam outlet 35 of the flash evaporator 9, and its third steam outlet connected to the external steam supply pipeline 23. The low-temperature, low-pressure saturated steam prepared by the flash evaporator 9 is compressed and its pressure and temperature increased by the steam compressor, and finally supplied to the steam user through the external steam supply pipeline 23.

[0036] In this application, by coupling an air source heat pump with biomass, the ambient temperature feedwater can be heated by an air source and supplied to the biomass boiler 8. The biomass boiler 8 then uses the heated high-temperature water to produce steam. Compared to directly heating ambient temperature feedwater with the biomass boiler 8 or directly using an electric boiler to produce steam, this reduces energy consumption and carbon emissions. When the biomass boiler 8 is not in use or lacks biomass fuel, the high-temperature water produced by the air source heat pump can be supplied to the flash evaporator 9. The low-temperature, low-pressure steam produced by the flash evaporator 9 is pressurized and heated by a steam compressor and then transported to the external steam supply pipeline 23 to provide steam to users. This rationally utilizes biomass fuel, ensuring steam supply while reducing carbon emissions.

[0037] In one embodiment of this application, multiple steam compressors are connected in series. The specific number is determined based on the required steam pressure, the parameters of each steam compressor, and the actual operating efficiency of each steam compressor. The multiple steam compressors are connected by a steam compression pipeline 22, which is equipped with a cooling section. If the steam temperature at the outlet of one steam compressor is too high, it will affect the operating efficiency of the next steam compressor. Therefore, water is sprayed from the feedwater pipeline 21 to cool the cooling section, thereby reducing the inlet temperature of the next steam compressor. Finally, the last steam compressor outputs steam at a suitable temperature and pressure into the external steam supply pipeline 23. Optionally, the cooling section is equipped with a heat exchanger to exchange heat between the feedwater and steam, thereby reducing the steam temperature.

[0038] In one embodiment of this application, the biomass boiler 8 mainly includes: a combustion chamber, an air distribution assembly, a flue gas emission assembly, and a heat exchange assembly. Biomass fuel accumulates in the combustion chamber to form a combustion layer. The air distribution assembly includes a primary air fan and a secondary air fan located outside the combustion chamber. The duct of the primary air fan extends into the combustion chamber near the combustion layer, providing main combustion air through the fuel layer. The duct of the secondary air fan extends into the combustion chamber above the combustion layer, providing oxygen for complete combustion, promoting turbulent mixing of flue gas, extending residence time, and reducing CO and unburned hydrocarbon emissions. The flue gas emission assembly includes a flue located at the top of the combustion chamber and connected to it a purification and dust removal device, an induced draft fan, and a chimney. The heat exchange assembly includes water-cooled walls and a steam drum. The water-cooled walls are heating surface pipes located around the combustion chamber, directly absorbing radiant heat from the flame and high-temperature flue gas, and are the main evaporative heating surface. One end of the heating surface pipe has a first water inlet 31, and the other end has a first steam outlet 32.

[0039] In one embodiment of this application, the air source heat pump can be a single unit or multiple units; currently, there are air source heat pumps that use carbon dioxide as the working fluid, and a single unit can directly heat room temperature water to 80-90°C. Optionally, a single air source heat pump can be a single-stage compression or multi-stage compression; multiple air source heat pumps can be cascaded in series or connected in parallel.

[0040] Preferably, the air source heat pump consists of two cascaded units connected in series. The first air source heat pump is formed by sequentially connecting the low-temperature evaporator 1, the low-temperature compressor 2, the heat-dissipating end of the cascaded heat exchanger 3, and the first throttling valve 4. The second air source heat pump is formed by sequentially connecting the heat-absorbing end of the cascaded heat exchanger 3, the high-temperature compressor 5, the high-temperature condenser 6, and the second throttling valve 7. The water inlet 38 of the high-temperature condenser 6 is connected to the water supply pipe 21, and the high-temperature water outlet 39 of the high-temperature condenser 6 is connected to the first water inlet 31 of the biomass boiler 8 and the second water inlet 33 of the flash evaporator 9. Optionally, a first working fluid, such as R410A or R32, circulates in the first air source heat pump, and a second working fluid, such as R134a or R245fa, circulates in the second air source heat pump.

[0041] The operating principle of the two air source heat pumps is as follows: In the first air source heat pump, the low-temperature evaporator 1 absorbs heat from the air and transfers the heat to the low-temperature, low-pressure first working fluid inside. The first working fluid then enters the low-temperature compressor 2, where it is pressurized and heated. The first working fluid then enters the heat-releasing end of the overlapping heat exchanger 3 and exchanges heat with the second working fluid at the heat-absorbing end of the overlapping heat exchanger 3. After heat exchange, the temperature of the first working fluid decreases, and it is then depressurized by the first throttling valve 4, resulting in a further decrease in pressure and temperature. After passing through the first throttling valve 4, it becomes the low-temperature, low-pressure first working fluid and returns to the low-temperature evaporator 1 for circulation. The principle of the second air source heat pump is the same as that of the first air source heat pump, except that the second working fluid is more adaptable to phase changes involving heat absorption and release at higher temperatures than the first working fluid. Furthermore, the second working fluid exchanges heat with the drainage from the second water outlet 36 of the feed water or flash evaporator 9 within the high-temperature condenser 6. The main components consuming electrical energy in both air source heat pumps are the low-temperature compressor 2 and the high-temperature compressor 5, which are connected to an external power supply system.

[0042] In one embodiment of this application, the main structure of the flash evaporator 9 consists of a tank, a throttling orifice located inside the tank, and a flash chamber. The throttling orifice is located above the flash chamber. A second water inlet 33 is located at the top of the tank and communicates with the throttling orifice. A second water inlet 34 is located on the side of the flash chamber and above the liquid surface, serving two purposes: to replenish water for the heat circulation and to maintain a low-temperature atmosphere in the space above the liquid surface of the flash chamber. A second steam outlet 35 is located at the upper part of the flash chamber. A second water outlet 36 is located at the bottom of the flash chamber. The operating principle is as follows: high-temperature water enters the tank and passes through the throttling orifice. The throttling orifice rapidly reduces the pressure of the high-temperature water, which lowers the boiling point of the water, allowing a small portion of the water to be converted into low-temperature, low-pressure saturated steam, while the majority is converted into low-temperature, low-pressure saturated water.

[0043] In one embodiment of this application, there may be three steam compressors, namely a first steam compressor 13, a second steam compressor 14, and a third steam compressor 15 connected in series. The steam ends of the three steam compressors are connected sequentially, and the steam outlet of the third steam compressor 15 is connected to the external steam supply pipeline 23. The steam compressors may be centrifugal steam compressors, mainly including a casing, an impeller and main shaft inside the casing, a diffuser and a volute, and a steam inlet and outlet provided on the casing. Low-temperature, low-pressure saturated steam enters from the inlet and its pressure is increased by the rotation of a single or multi-stage impeller. The diffuser is used to convert the kinetic energy of the high-speed steam at the outlet of the impeller section into static pressure energy, thereby increasing the steam pressure and temperature, and finally outputting the steam from the outlet.

[0044] Preferably, the second water inlet 34 of the flash evaporator 9 is connected to the water supply pipeline 21; the second water inlet 34 is equipped with a flow valve 12.

[0045] Preferably, a circulating water pump 10 and a first valve 16 are provided between the second water outlet 37 of the flash evaporator 9 and the water inlet 38 of the air source heat pump. Optionally, the circulating water pump 10 can be a booster pump, which can increase the pressure of the water circulation, so that the high-temperature water discharged by the air source heat pump has a certain pressure. The booster pump mainly includes a centrifugal impeller and a volute. A water inlet is provided at the center of one side of the volute, and a water outlet is provided on the outer periphery of the volute. The operating principle is as follows: water enters the volute from the water inlet and flows through the centrifugal impeller. The centrifugal impeller increases the kinetic energy of the water and throws the water from the center onto the inner wall of the volute, converting the kinetic energy into static pressure energy, thereby increasing the water pressure.

[0046] Preferably, the water supply pipeline 21 is equipped with a water supply pump 11 and a second valve 17; the second water inlet 33 of the flash evaporation device 9 is equipped with a third valve 18; and the first water inlet 31 of the biomass boiler 8 is equipped with a fourth valve 19.

[0047] The second water inlet 234 is directly connected to the water supply pipeline 21 and a fifth valve 20 is installed.

[0048] When steam is generated using the bio-boiler 8, close the first valve 16, the third valve 18 and 20, and open the second valve 17 and the fourth valve 19. When steam is generated using the flash evaporator 9, close the fourth valve 19 and the second valve 17, and open the fifth valve 20, the first valve 16, the third valve 18 and the flow valve 12.

[0049] In the description of this utility model, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this utility model. In this utility model, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0050] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of this application and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of this application should be included within the protection scope of this application. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A steam supply system for comprehensive energy utilization, characterized in that, include: An air source heat pump is used to heat the water supply by using electrical energy and air energy. Its water supply inlet (38) is connected to the water supply pipeline (21). The biomass boiler (8) has its first water inlet (31) connected to the high-temperature water outlet (39) of the air source heat pump and its first steam outlet (32) connected to the external steam supply pipeline (23) for burning biomass fuel to produce steam from high-temperature water. The flash evaporator (9) has its second water inlet (33) connected to the high-temperature water outlet (39) of the air source heat pump, and is used to prepare steam and water using high-temperature water; the second water outlet (36) of the flash evaporator (9) is connected to the water supply inlet (38) of the air source heat pump, and the second water inlet (34) of the flash evaporator (9) is connected to the water supply pipeline (21); The steam compressor has its third steam inlet (37) connected to the second steam outlet (35) of the flash evaporator (9), and its third steam outlet connected to the external steam supply pipeline (23).

2. The steam supply system for comprehensive energy utilization according to claim 1, characterized in that, The steam compressors are multiple units connected in series, and the multiple steam compressors are connected by a steam compression pipeline (22). The steam compression pipeline (22) is provided with a cooling section, which is used to reduce the temperature of the steam flowing inside by using the water supply from the water supply pipeline (21).

3. The steam supply system for comprehensive energy utilization according to claim 1, characterized in that, The air source heat pump is a single unit or multiple units cascaded in series.

4. The steam supply system for comprehensive energy utilization according to claim 1, characterized in that, The air source heat pump consists of two cascaded units connected in series. The low-temperature evaporator (1), the low-temperature compressor (2), the heat-dissipating end of the overlapping heat exchanger (3), and the first throttling valve (4) are sequentially connected in a loop to form the first air source heat pump; The heat absorption end of the superimposed heat exchanger (3), the high-temperature compressor (5), the high-temperature condenser (6), and the second throttle valve (7) are sequentially and cyclically connected to form a second air source heat pump; The water inlet of the high-temperature condenser (6) is connected to the water supply pipeline (21), and the high-temperature water outlet of the high-temperature condenser (6) is connected to the first water inlet (31) of the biomass boiler (8) and the second water inlet of the flash evaporator (9), respectively.

5. The steam supply system for comprehensive energy utilization according to claim 1, characterized in that, The second water outlet (36) of the flash evaporator (9) and the water inlet (38) of the air source heat pump are equipped with a circulating water pump (10) and a first valve (16).

6. The steam supply system for comprehensive energy utilization according to claim 1, characterized in that, The water supply pipeline (21) is equipped with a water supply pump (11) and a second valve (17); The second water inlet (33) of the flash evaporator (9) is equipped with a third valve (18); The first water inlet (31) of the biomass boiler (8) is equipped with a fourth valve (19).

7. The steam supply system for comprehensive energy utilization according to claim 2, characterized in that, The second water inlet (34) is directly connected to the water supply pipeline (21) by a fifth valve (20).

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