A flue gas de - whitening device, an integrated device for boilers and waste heat recovery

Abstract

The present disclosure provides a flue gas de - whiting device, a boiler and waste heat recovery integrated device, which relates to the technical field of waste heat recovery. The flue gas de - whiting device includes: an economizer and a condensation heat recovery device installed in the flue; when the boiler connected to the flue burns, flue gas is generated and the flue gas flows through the flue; the economizer is installed closer to the boiler than the condensation heat recovery device; the flue gas exchanges heat with the economizer first in the flue and then exchanges heat with the condensation heat recovery device. The boiler and waste heat recovery integrated device includes: a boiler, a flue and a waste heat recovery device. The boiler includes a combustion chamber, a heat medium chamber and a steam chamber. The combustion chamber is connected to the flue. The flue gas generated by the combustion of fuel in the combustion chamber exchanges heat with the heat medium in the heat medium chamber once and then enters the flue. The flue gas exchanges heat with the economizer first in the flue and then exchanges heat with the condensation heat recovery device. The present disclosure reduces the discharge temperature of the flue gas to below 20 °C, recovers the latent heat and sensible heat in the flue gas, and reduces carbon emissions and energy waste.

Description

Technical Field

[0001] The present disclosure relates to the field of waste heat recovery, and particularly to an integrated device for flue gas de - whitening, boiler and waste heat recovery. Background Art

[0002] Since the high - temperature flue gas discharged from small and medium - sized gas boilers in civil and industrial buildings is not subjected to waste heat recovery, a large amount of high - grade energy is wasted. At the same time, the high - temperature flue gas contains a large amount of water vapor. During the process of discharging to the outside, the water vapor in the flue gas will gradually condense into fog, resulting in the phenomenon of "white smoke" coming out of the chimney. This not only affects the appearance but also causes problems such as rain and mist near the chimney and the risk of icing on the ground. Summary of the Invention

[0003] Embodiments of the present invention provide an integrated device for flue gas de - whitening, boiler and waste heat recovery, which recovers the waste heat of the flue, reduces the discharge temperature of the flue gas to below 20°C, recovers the latent heat and sensible heat in the flue gas, and reduces carbon emissions and energy waste.

[0004] To achieve the above - mentioned purpose, the embodiments of the present invention adopt the following technical solutions:

[0005] On the one hand, a flue gas de - whitening device is provided, including: an economizer and a condensation heat recovery device installed in the flue;

[0006] When the boiler connected to the flue burns, flue gas is generated and the flue gas flows through the flue;

[0007] The economizer is installed closer to the boiler than the condensation heat recovery device;

[0008] The flue gas exchanges heat with the economizer first and then with the condensation heat recovery device in the flue.

[0009] For the commercially available vacuum gas boiler, the flue gas is reduced from about 180°C to about 60°C after heat exchange with the economizer, and the flue gas is reduced from 60°C to 20°C after passing through the condensation heat recovery device. When the flue gas temperature sensor on the boiler exhaust pipe monitors that the flue gas is higher than 20°C, the flue gas temperature sensor will transmit the temperature signal to the PLC controller. The PLC controller will judge whether the temperature signal is higher than 20°C. If it exceeds 20°C, the PLC controller will output an electrical signal to increase the rotational speed of the compressor motor, thereby increasing the flow rate of the refrigerant in the compressor, and thus strengthening the heat exchange capacity of the condensation heat recovery device, so as to achieve the purpose of reducing the flue gas temperature to 20°C.

[0010] Based on one aspect, in some embodiments, it further includes: a heat medium flow channel installed on the outer peripheral wall of the flue, and the heat medium in the heat medium flow channel exchanges heat with the flue gas.

[0011] Based on one aspect, in some embodiments, the heat medium flow channel extends along the flue from the boiler until it extends beyond the condensation heat recovery device.

[0012] For a 1-ton gas boiler with a capacity of 700 Kw, the thermal efficiency of a general gas boiler is about 90%, and the calorific value of natural gas is about 33,000 KJ / Nm 3 , and the hourly consumption of natural gas is about 84.6 Nm 3 / h, the hourly flue gas emission is about 1,060 m 3 / h, the flue gas density is about 1.02 kg / m 3 , the specific heat capacity of the flue gas at constant pressure is about 1.133 KJ / (kg·°C), and the latent heat value of water vapor in the flue gas is about 2,368 KJ / kg. Therefore, in the present invention, the heat medium absorbs about 700 Kw of heat from the flue; the temperature of the flue gas is reduced from about 180 °C to about 60 °C through the economizer. At this time, since the partial pressure of water vapor in the flue gas does not reach the saturation state, no water vapor condensation occurs, so the economizer only absorbs the sensible heat of the flue gas. At this time, the economizer absorbs about 40.6 Kw of heat from the flue; the temperature of the flue gas is reduced from about 60 °C to about 20 °C through the condensing heat recovery device. Since the partial pressure of water vapor in the flue gas reaches the saturation state at 55.4 °C, water vapor condensation occurs in the flue gas at 55.4 °C. Therefore, the condensing heat recovery device absorbs both the sensible heat and the latent heat of the flue gas. The condensing heat recovery device absorbs about 75.6 Kw of heat from the flue, and the condensation water volume of the condensing heat recovery device is about 94.4 kg / h. From the above calculations, it can be seen that the proportions of the heat medium, the economizer, and the condensing heat recovery device in digesting the heat from the flue are 85.76%, 4.97%, and 9.27% respectively. According to this proportion, it can be found that the economizer only recovers the sensible heat of the flue gas and does not eliminate the water vapor in the flue gas, while the heat recovery amount of the condensing heat recovery device is almost twice that of the economizer, and the water vapor in the flue gas is deeply condensed, making the proportion of water vapor in the flue gas extremely small, thus realizing the "de-white" effect during the emission of the flue gas to the external environment.

[0013] On the one hand, in some embodiments, the heat medium flow channel is communicated with the heat medium chamber inside the boiler;

[0014] The heat medium flows in the heat medium chamber and the heat medium flow channel.

[0015] On the one hand, in some embodiments, it further includes: a compressor and a heat exchanger installed close to the flue;

[0016] Refrigerant flows on one side of the heat exchanger. The heat exchanger, the compressor, and the condensing heat recovery device are interconnected, and the refrigerant circulates among the heat exchanger, the compressor, and the condensing heat recovery device. The refrigerant exchanges heat with the flue gas in the condensing heat recovery device;

[0017] Domestic water flows on the other side of the heat exchanger, and the other side of the heat exchanger is also connected to the energy saver. After the domestic water exchanges heat with the refrigerant once in the heat exchanger, it enters the energy saver to exchange heat with the flue gas in the flue for the second time.

[0018] On the other hand, a boiler and waste heat recovery integrated device is provided, including: a boiler, a flue, and a waste heat recovery device. The waste heat recovery device is a flue gas dewhiting device of the above solution;

[0019] The boiler includes a combustion chamber, a heat medium chamber, and a steam chamber. The combustion chamber is connected to the flue. The flue gas generated by burning fuel in the combustion chamber exchanges heat with the heat medium in the heat medium chamber once and then enters the flue. The flue gas exchanges heat with the energy saver first and then with the condensation heat recovery device in the flue;

[0020] While the heat medium in the heat medium chamber exchanges heat with the flue gas, it also exchanges heat with the heat generated by the combustion of the fuel in the combustion chamber.

[0021] Based on the other hand, in some embodiments, the boiler further includes a blower;

[0022] The air duct of the blower is connected to the combustion chamber.

[0023] Based on the other hand, in some embodiments, the boiler and waste heat recovery integrated device further includes a tubular heat exchange module;

[0024] The steam chamber is connected to the heat medium chamber;

[0025] The tubular heat exchange module is installed in the steam chamber, and the water medium flowing in the tubular heat exchange module exchanges heat with the hot steam in the steam chamber.

[0026] Based on the other hand, in some embodiments, natural gas and air enter the combustion chamber through the blower to burn and generate high-temperature flue gas;

[0027] The high-temperature flue gas exchanges heat with the hot water in the heat medium chamber, and the hot water absorbs heat to form high-temperature steam;

[0028] The high-temperature steam enters the steam chamber and heats the circulating hot water in the tubular heat exchange module;

[0029] After the high-temperature steam releases heat, it forms condensed water and enters the heat medium chamber to continue exchanging heat with the high-temperature flue gas.

[0030] Based on the other hand, in some embodiments, the tubular heat exchange module includes a first tubular heat exchanger and a second tubular heat exchanger;

[0031] The first tubular heat exchanger and the second tubular heat exchanger are installed in parallel in the steam chamber;

[0032] The second tubular heat exchanger is connected to the other side of the heat exchanger of the flue gas dewhiting device;

[0033] The temperature of the hot water flowing out of the second tubular heat exchanger is higher than that of the hot water flowing out of the first tubular heat exchanger.

[0034] On the other hand, in some embodiments, heating water flows in the first tubular heat exchanger, and domestic water flows in the second tubular heat exchanger;

[0035] The temperature of the heating water flowing out of the first tubular heat exchanger is lower than that of the domestic water flowing out of the second tubular heat exchanger;

[0036] The heating water exchanges heat with high-temperature steam in the first tubular heat exchanger;

[0037] After the domestic water exchanges heat with the refrigerant once in the heat exchanger, it enters the economizer of the flue gas dewhitening device; after the domestic water exchanges heat with the flue gas in the economizer for the second time, it enters the second tubular heat exchanger; the domestic water exchanges heat with high-temperature steam three times in the second tubular heat exchanger.

[0038] In the present disclosure, there are at least the following technical effects or advantages:

[0039] In the embodiments of the present invention, the waste heat of the flue is recovered through the economizer and the condensation heat recovery device, the discharge temperature of the flue gas is reduced to below 20°C, the latent heat and sensible heat in the flue gas are recovered, and carbon emissions and energy waste are reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for describing the embodiments of the present invention or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0041] Figure 1 Schematic diagram of the integrated boiler and waste heat recovery device according to some embodiments of the present disclosure Figure One ;

[0042] Figure 2 Schematic diagram of the integrated boiler and waste heat recovery device according to some embodiments of the present disclosure Figure Two ;

[0043] Figure 3 Boiler sectional view according to some embodiments of the present disclosure;

[0044] Figure 4 Condensation heat recovery device sectional view according to some embodiments of the present disclosure;

[0045] Reference Numerals: 100 - flue; 200 - boiler; 300 - heat medium flow channel; 400 - first tubular heat exchanger; 500 - second tubular heat exchanger; 1 - base; 2 - blower; 3 - heat medium chamber; 4 - combustion chamber; 5 - steam chamber; 6 - economizer; 7 - electronic expansion valve; 8 - compressor; 9 - condensation heat recovery device; 10 - flue gas temperature sensor; 11 - first flue; 12 - U-shaped drain bend; 13 - second flue; 14 - angle steel flange; 15 - roof panel; 16 - conical hood; 17 - fixed support; 18 - round umbrella-shaped wind cap; 19 - flowmeter; 20 - pressure gauge 1; 21 - thermometer 1; 22 - PLC controller; 23 - thermometer 2; 24 - pressure gauge 2; 25 - plate heat exchanger; 26 - waste heat recovery equipment room; 27 - water level gauge; 30 - vacuum pump; 31 - stop valve; 32 - explosion-proof valve; 33 - digital vacuum gauge; 35 - hot water heat exchange tube; 36 - tube box; 37 - tube sheet; 38 - split partition; 39 - control thermometer; 40 - safety thermometer; 41 - flue gas heat exchange tube; 42 - cylinder body; 43 - fin; 44 - finned tube; 45 - connecting pipe. Detailed Embodiments

[0046] The present disclosure will be described in detail below with reference to the embodiments shown in the drawings. However, it should be noted that these embodiments do not limit the present disclosure, and any equivalent transformation or substitution in terms of function, method, or structure made by those of ordinary skill in the art based on these embodiments shall fall within the protection scope of the present disclosure.

[0047] Currently, there is no mature technology for recovering the waste heat of flue gas from small and medium-sized gas boilers and achieving the whitening of flue gas. With the continuous improvement of the country's energy conservation and emission reduction requirements and the continuous improvement of scientific and technological levels, the technology of using heat pumps for efficient recovery of flue gas waste heat can achieve deep recovery of the sensible heat and latent heat of the flue gas of natural gas boilers. At the same time, the process of whitening the flue gas before emission is completed during the cooling and condensation process of flue gas heat recovery.

[0048] Although the technology of using heat pumps for efficient recovery of flue gas waste heat has certain R & D and application experiences, there are still a series of problems that need to be solved through further technological R & D and product upgrades.

[0049] 1) Existing waste heat recovery heat pumps can only reduce the flue gas temperature to about 60°C, which only recovers most of the sensible heat of the flue gas, while the latent heat of the flue gas is not recovered, resulting in the neglect of this part of the invisible energy.

[0050] 2) Existing technologies for efficient recovery of flue gas waste heat using heat pumps are mostly applied to large boilers, which are not easy to install and have a large initial investment, and are not suitable for medium and small boilers.

[0051] 3) There are relatively few standardized, modeled, and directly selectable flue gas waste heat recovery products, and it is somewhat difficult for users to select products.

[0052] Embodiments of the present disclosure provide a flue gas de - whitening device. Please refer to Figure 1 and Figure 2 , including: an economizer 6 and a condensation heat recovery device 9 installed in the flue 100; when the boiler 200 connected to the flue 100 burns, flue gas is generated and flows through the flue 100; the economizer 6 is installed closer to the boiler 200 than the condensation heat recovery device 9; the flue gas exchanges heat with the economizer 6 first and then with the condensation heat recovery device 9 in the flue 100.

[0053] Embodiments of the present disclosure recover the waste heat of the flue 100 through the economizer 6 and the condensation heat recovery device 9, reduce the flue gas discharge temperature to below 20°C, recover the latent heat and sensible heat in the flue gas, and reduce carbon emissions and energy waste.

[0054] More specifically, please refer to Figure 2 , Figure 3 and Figure 4, in practical applications, the air duct of the blower 2 is connected to the combustion chamber 4 inside the boiler. The combustion chamber 4 is connected to the inlet of the flue gas heat exchange tube 41. The outlet of the flue gas heat exchange tube 41 is connected to the inlet of the first flue 11. The economizer 6 and the condensing heat recovery device 9 are installed in the first flue 11. The outlet of the first flue 11 is connected to the second flue 13. The second flue 13 passes through the roof panel 15. The conical cover 16 is connected to the roof panel 15 around the second flue 13. The angle steel flange 14 is connected to the second flue 13. The fixed support 17 is mounted on the second flue 13. The round umbrella-shaped wind cap 18 is mounted on the fixed support 17. The boiler is installed on the base 1 through supports. The blower 2 is installed on the base 1. The air duct of the blower 2 is connected to the combustion chamber 4 inside the boiler. The heat medium chamber 3 is filled with heat medium water. The flue gas heat exchange tube 41 and the combustion chamber 4 are arranged in the heat medium chamber 3. Above the heat medium chamber 3 is the steam chamber 5. The control thermometer 39, the safety thermometer 40 and the water level gauge 27 are installed at the junction of the heat medium chamber 3 and the steam chamber 5. The hot water heat exchange tubes 35 of the first tubular heat exchanger 400 and the second tubular heat exchanger 500 are installed in the steam chamber 5. The tube boxes 36 and tube plates 37 of the first tubular heat exchanger 400 and the second tubular heat exchanger 500 are installed outside the steam chamber 5. The partition plates 38 of the first tubular heat exchanger 400 and the second tubular heat exchanger 500 are installed between the tube boxes 36 and the tube plates 37. The stop valve 31, the explosion-proof valve 32 and the digital vacuum gauge 33 are installed on the top of the steam chamber 5. The outlet of the stop valve 31 is connected to the inlet of the vacuum pump 30. The outlet of the vacuum pump 30 leads directly to the external environment. The economizer 6 and the condensing heat recovery device 9 are installed in the first flue 11. The electronic expansion valve 7, the flow meter 19, the pressure gauge 1 20, the thermometer 1 21, the PLC controller 22, the thermometer 2 23, the pressure gauge 2 24 and the plate heat exchanger 25 are installed in the waste heat recovery equipment room 26. The refrigerant outlet side port of the compressor 8 is connected to the Ri port of the plate heat exchanger 25. The Ro port of the plate heat exchanger 25 is connected to the refrigerant inlet side port of the electronic expansion valve 7. The refrigerant outlet side port of the electronic expansion valve 7 is connected to the refrigerant inlet side port of the condensing heat recovery device 9. The refrigerant outlet side port of the condensing heat recovery device 9 is connected to the refrigerant inlet side port of the compressor 8. The Wi port of the plate heat exchanger 25 is connected to the return water port of the domestic hot water. The Wo port of the plate heat exchanger 25 is connected to the domestic hot water inlet side port of the economizer 6. The domestic hot water outlet side port of the economizer 6 is connected to the domestic hot water inlet side port of the second tubular heat exchanger 500.

[0055] Based on the above solution, please continue to refer to Figure 1 and Figure 2 , in addition to the economizer 6 and the condensing heat recovery device 9, the flue gas dewhitening device of the present disclosure embodiment further includes a heat medium flow channel 300 installed on the outer peripheral wall of the flue 100, and the heat medium in the heat medium flow channel 300 exchanges heat with the flue gas.

[0056] Please continue to refer toFigure 1 and Figure 2 Preferably, the heat medium flow channel 300 extends along the flue 100 from the boiler 200 until it extends beyond the condensation heat recovery device 9. Please continue to refer to Figure 1 and Figure 2 In practical applications, the heat medium flow channel 300 of the embodiment of the present disclosure communicates with the heat medium chamber 3 inside the boiler 200; the heat medium flows in the heat medium chamber 3 and the heat medium flow channel 300.

[0057] Based on the above solution, please continue to refer to Figure 1 and Figure 2 In addition to the economizer 6, the condensation heat recovery device 9 and the heat medium flow channel 300, the flue gas de - whitening device of the embodiment of the present disclosure further includes: a compressor 8 and a heat exchanger installed near the flue 100; refrigerant flows on one side of the heat exchanger, and the heat exchanger, the compressor 8 and the condensation heat recovery device 9 are interconnected, and the refrigerant circulates between the heat exchanger, the compressor 8 and the condensation heat recovery device 9, and the refrigerant exchanges heat with the flue gas in the flue 100 in the condensation heat recovery device 9; domestic water flows on the other side of the heat exchanger, and the other side of the heat exchanger is also connected to the economizer 6, and the domestic water exchanges heat with the refrigerant once in the heat exchanger and then enters the economizer 6 to exchange heat with the flue gas in the flue 100 a second time.

[0058] Please continue to refer to Figure 2 、 Figure 3 and Figure 4 In the embodiment of the present disclosure, the hot water heat exchange tubes 35 of the first tubular heat exchanger 400 and the second tubular heat exchanger 500 are installed in the steam chamber 5, the ports of the hot water heat exchange tubes 35 of the first tubular heat exchanger 400 and the second tubular heat exchanger 500 are inserted into the tube sheet 37, wherein the second tubular heat exchanger 500 is located above the first tubular heat exchanger 400, the tube boxes 36 and the tube sheet 37 of the first tubular heat exchanger 400 and the second tubular heat exchanger 500 are installed outside the steam chamber 5, the partition plates 38 for dividing the flow path of the first tubular heat exchanger 400 and the second tubular heat exchanger 500 are installed between the tube boxes 36 and the tube sheet 37, the hot water inlet and outlet of the first tubular heat exchanger 400 are located on the left side of the boiler, the hot water inlet and outlet of the second tubular heat exchanger 500 are located on the right side of the boiler, and the port of the side where the domestic hot water of the second tubular heat exchanger 500 flows in is connected to the port of the side where the domestic hot water flows out of the economizer 6.

[0059] Please refer to Figure 1 、 Figure 2 、 Figure 3 and Figure 4, embodiments of the present disclosure further provide an integrated boiler and waste heat recovery device, including: a boiler 200, a flue 100, and a waste heat recovery device, where the waste heat recovery device is a flue gas dewhitening device of the above solution; the boiler 200 includes a combustion chamber 4, a heat medium chamber 3, and a steam chamber 5. The combustion chamber 4 is communicated with the flue 100. The flue gas generated by burning fuel in the combustion chamber 4 exchanges heat with the heat medium in the heat medium chamber 3 once and then enters the flue 100. The flue gas exchanges heat with the economizer 6 first and then with the condensation heat recovery device 9 in the flue 100. The heat medium in the heat medium chamber 3 exchanges heat with the flue gas and also exchanges heat with the heat generated by the fuel combustion in the combustion chamber 4. In practical applications, the boiler is supported and installed on a base 1, a blower 2 is installed on the base 1, the air duct of the blower 2 is connected to the combustion chamber 4 inside the boiler, the heat medium chamber 3 is filled with heat medium water, the flue gas heat exchange tubes 41 and the combustion chamber 4 are arranged in the heat medium chamber 3, the steam chamber 5 is above the heat medium chamber 3, a control thermometer 39, an insurance thermometer 40, and a water level gauge 27 are installed at the junction of the heat medium chamber 3 and the steam chamber 5, the hot water heat exchange tubes 35 of the first tubular heat exchanger 400 and the second tubular heat exchanger 500 are installed in the steam chamber 5, the tube boxes 36 and tube plates 37 of the first tubular heat exchanger 400 and the second tubular heat exchanger 500 are installed outside the steam chamber 5, the partition plates 38 of the first tubular heat exchanger 400 and the second tubular heat exchanger 500 are installed between the tube box 36 and the tube plate 37, a stop valve 31, an explosion-proof valve 32, and a digital vacuum gauge 33 are installed on the top of the steam chamber 5, the outlet of the stop valve 31 is connected to the inlet of a vacuum pump 30, and the outlet of the vacuum pump 30 leads directly to the external environment. The economizer 6 and the condensation heat recovery device 9 are installed in the first flue 11. An electronic expansion valve 7, a flow meter 19, a pressure gauge 1 20, a thermometer 1 21, a PLC controller 22, a thermometer 2 23, a pressure gauge 2 24, and a plate heat exchanger 25 are installed in the waste heat recovery equipment chamber 26. The refrigerant outflow side port of a compressor 8 is connected to the Ri port of the plate heat exchanger 25. The Ro port of the plate heat exchanger 25 is connected to the refrigerant inflow side port of the electronic expansion valve 7. The refrigerant outflow side port of the electronic expansion valve 7 is connected to the refrigerant inflow side port of the condensation heat recovery device 9. The refrigerant outflow side port of the condensation heat recovery device 9 is connected to the refrigerant inflow side port of the compressor 8. The Wi port of the plate heat exchanger 25 is connected to the return water port of domestic hot water. The Wo port of the plate heat exchanger 25 is connected to the domestic hot water inflow side port of the economizer 6. The domestic hot water outflow side port of the economizer 6 is connected to the domestic hot water inflow side port of the second tubular heat exchanger 500.

[0060] Further, the boiler in the embodiments of the present disclosure is a vacuum gas boiler, which may include a blower 2, a heat medium chamber 3, a combustion chamber 4, an economizer 6, a first flue 11, a water level gauge 27, a vacuum pump 30, a stop valve 31, a relief valve 32, a digital vacuum gauge 33, a steam chamber 5, a control thermometer 39, a safety thermometer 40, a flue gas heat exchange tube 41 and a cylinder body 42. Natural gas and air enter the combustion chamber 4 through the blower 2 for combustion to generate high-temperature flue gas. The high-temperature flue gas exchanges heat with the hot water in the heat medium chamber 3 through the flue gas heat exchange tube 41. The hot water absorbs heat to form high-temperature steam. The high-temperature steam enters the steam chamber 5 and heats the circulating hot water in the first tubular heat exchanger 400 and the second tubular heat exchanger 500 through the hot water heat exchange tube 35. After the high-temperature steam releases heat, it forms condensed water and enters the heat medium chamber 3 to continue exchanging heat with the high-temperature flue gas, thus completing the cycle. After the flue gas completes the heat exchange with the hot water in the heat medium chamber 3, its temperature drops to 180 - 250 °C. Then, the flue gas exchanges heat with the domestic hot water in the economizer 6 again, and the temperature drops to about 60 °C. The inlet of the economizer 6 is connected to the Wo port of the plate heat exchanger 25, and the outlet of the economizer 6 is connected to the inlet of the second tubular heat exchanger 500. During the whole process of the boiler operation, the heat medium in the boiler does not enter, exit, increase or decrease, and is only enclosed in the heat medium chamber 3 and the steam chamber 4. This invention patent is for small and medium-sized vacuum gas boilers with a heating capacity of 1 to 10 tons per hour, forming 10 grades (1 ton per hour, 2 tons per hour, 3 tons per hour..., 10 tons per hour). The flue gas volume discharged by the vacuum gas boilers of each grade is also corresponding. Therefore, the compressor 8, the economizer 6, the condensing heat recovery device 9, the plate heat exchanger 25, and the electronic expansion valve 7 also form 10 corresponding selections according to the 10 grades of the boiler.

[0061] Please continue to refer to Figure 1 、 Figure 2 、 Figure 3 and Figure 4 As shown in FIGS. 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10, in addition to including a combustion chamber 4, a heat medium chamber 3, and a steam chamber 5, the boiler 200 in the embodiments of the present disclosure further includes a blower 2; the air duct of the blower 2 is connected to the combustion chamber 4. The air duct of the blower 2 is connected to the combustion chamber 4 inside the boiler. The combustion chamber 4 is connected to the inlet of the flue gas heat exchange tube 41. The outlet of the flue gas heat exchange tube 41 is connected to the inlet of the first flue 11. The economizer 6 and the condensing heat recovery device 9 are installed in the first flue 11. The outlet of the first flue 11 is connected to the second flue 13. The second flue 13 passes through the roof panel 15. The conical cover 16 surrounds the second flue 13 and is connected to the roof panel 15. The angle steel flange 14 is connected to the second flue 13. The fixed support 17 is mounted on the second flue 13. The round umbrella-shaped wind cap 18 is mounted on the fixed support 17.

[0062] Based on the above solution, the boiler 200 and the waste heat recovery integrated device of the embodiments of the present disclosure further include a tubular heat exchange module; the steam chamber 5 is communicated with the heat medium chamber 3; the tubular heat exchange module is installed in the steam chamber 5, and the water medium flowing in the tubular heat exchange module exchanges heat with the hot steam in the steam chamber 5.

[0063] Please refer to Figure 1 、 Figure 2 、 Figure 3 and Figure 4 , preferably, natural gas and air enter the combustion chamber 4 through the blower 2 for combustion to generate high-temperature flue gas; the high-temperature flue gas exchanges heat with the hot water in the heat medium chamber 3, and the hot water absorbs heat to form high-temperature steam; the high-temperature steam enters the steam chamber 5 to heat the circulating hot water in the tubular heat exchange module; after releasing heat, the high-temperature steam forms condensed water and enters the heat medium chamber 3 to continue to exchange heat with the high-temperature flue gas.

[0064] Please refer to Figure 1 、 Figure 2 、 Figure 3 and Figure 4 , in practical applications, the tubular heat exchange module of the embodiments of the present disclosure includes a first tubular heat exchanger 400 and a second tubular heat exchanger 500; the first tubular heat exchanger 400 and the second tubular heat exchanger 500 are installed in parallel in the steam chamber 5; the second tubular heat exchanger 500 is communicated with the other side of the heat exchanger of the flue gas dewhitening device; the temperature of the hot water flowing out of the second tubular heat exchanger 500 is higher than the temperature of the hot water flowing out of the first tubular heat exchanger 400. Preferably, the hot water heat exchange tubes 35 of the first tubular heat exchanger 400 and the second tubular heat exchanger 500 are installed in the steam chamber 5, and the ports of the hot water heat exchange tubes 35 of the first tubular heat exchanger 400 and the second tubular heat exchanger 500 are inserted into the tube sheet 37, wherein the second tubular heat exchanger 500 is located above the first tubular heat exchanger 400, the tube boxes 36 and the tube sheet 37 of the first tubular heat exchanger 400 and the second tubular heat exchanger 500 are installed outside the steam chamber 5, the partition plates 38 for dividing the flow paths of the first tubular heat exchanger 400 and the second tubular heat exchanger 500 are installed between the tube boxes 36 and the tube sheet 37, the hot water inlet and outlet of the first tubular heat exchanger 400 are located on the left side of the boiler, the hot water inlet and outlet of the second tubular heat exchanger 500 are located on the right side of the boiler, and the port of the side where the domestic hot water of the second tubular heat exchanger 500 flows in is connected to the port of the side where the domestic hot water of the economizer 6 flows out.

[0065] More specifically, the heated medium in the first tubular heat exchanger 400 is the return water of the user heating system, the hot water heat exchange tubes 35 are arranged in the steam chamber 5, and the heating return water in the hot water heat exchange tubes 35 exchanges heat with the high-temperature steam to become the supply water of the user heating system, wherein the structural form of the heat exchange tubes is U-shaped heat exchange tubes.

[0066] The heat-absorbing medium in the second tubular heat exchanger 500 is the return water of the user's domestic hot water system. The return water of the domestic hot water system first enters the plate heat exchanger 25 to exchange heat with the refrigerant, absorbs heat and then enters the economizer 6 to continue absorbing the heat of the high-temperature flue gas, and then enters the second tubular heat exchanger 500 again. The hot water heat exchange tubes of the second tubular heat exchanger 500 are arranged in the steam chamber 5. The return water of the domestic hot water in the hot water heat exchange tubes 35 exchanges heat with the high-temperature steam and becomes the supply water of the user's domestic hot water system. The structural form of the heat exchange tubes is U-shaped heat exchange tubes. The U-shaped drain bend 12 is used to collect the condensed water generated by the latent heat released by the flue gas and prevent the flue gas from escaping. There is a water column with a certain height in the U-shaped drain bend 12.

[0067] In the first tubular heat exchanger 400 of the embodiment of the present disclosure, heating water flows, and in the second tubular heat exchanger 500, domestic water flows; the temperature of the heating water flowing out of the first tubular heat exchanger 400 is lower than the temperature of the domestic water flowing out of the second tubular heat exchanger 500; the heating water exchanges heat with the high-temperature steam in the first tubular heat exchanger 400; the domestic water exchanges heat with the refrigerant once in the heat exchanger and then enters the economizer 6 of the flue gas dewhitening device; the domestic water exchanges heat with the flue gas in the economizer 6 and the flue 100 for the second time and then enters the second tubular heat exchanger 500; the domestic water exchanges heat with the high-temperature steam three times in the second tubular heat exchanger 500.

[0068] In practical applications, the waste heat recovery device of the present disclosure embodiment includes a compressor 8, a plate heat exchanger 25, an electronic expansion valve 7, and a condensation heat recovery device 9. Among them, the compressor 8, the plate heat exchanger 25, and the electronic expansion valve 7 are all arranged in the waste heat recovery device chamber 26 and integrated with a vacuum gas boiler. After the flue gas passes through the condensation heat recovery device 9, the medium temperature of about 60 °C is reduced to a low temperature of about 20 °C, and the sensible heat and latent heat of the flue gas are deeply recovered. The refrigerant used in the flue gas waste heat recovery device is R134a, which is a new type of environmentally friendly refrigerant that does not damage the ozone layer and has the characteristics of stability, non-toxicity, and high refrigeration efficiency. Through calculation, when the boiler is within 3 tons of steam, it is more economical to select a variable frequency scroll compressor; when the boiler is between 3 and 10 tons of steam, it is more economical to select a variable frequency screw compressor. Pressure gauges (20, 24) and thermometers (21, 23) are arranged at the inlet and outlet of the compressor 8 to monitor the pressure and temperature of the refrigerant at the inlet and outlet of the compressor 8, prevent the compressor 8 from being damaged due to excessive refrigerant pressure and temperature, and a flow meter 19 is arranged at the inlet of the compressor 8 to monitor the real-time flow rate of the refrigerant. The condensation heat recovery device 9 is a stainless steel finned tube heat exchanger, which is treated with an anti-corrosion and heat-conducting ceramic coating on the surface, and the inside of the first flue 11 is treated with a corrosion-resistant coating. The structural parameters of the condensation heat recovery device 9 are: the finned tube 44 has a tube pitch of 38 mm, a row pitch of 32 mm, an outer diameter of the finned tube 44 of 15.5 mm, a wall thickness of the finned tube 44 of 0.4 mm, a thickness of the fin 43 of 0.11 mm, a fin 43 spacing of 3.2 mm, and the finned tubes 44 are arranged in an isosceles or equilateral cross arrangement (enhancing the internal turbulence of the flue gas to strengthen heat transfer), and the inlet and outlet of the finned tubes 44 are connected by a connecting pipe 45. The condensation heat recovery device 9 is arranged in the first flue 11 and as close to the compressor 8 as possible to avoid the temperature of the refrigerant entering the compressor 8 being too high. In addition, the cross-section of the condensation heat recovery device 9 is made as large as possible and the length is made as short as possible to prevent the flue gas pressure drop from being too large and causing problems with difficult exhaust. A flue gas temperature sensor 10 is arranged at the rear of the condensation heat recovery device 9 to transmit the exhaust gas temperature signal to the PLC controller 22, and the PLC controller 22 controls the motor speed of the compressor 8 according to the exhaust gas temperature signal, thereby adjusting the refrigerant flow rate to control the exhaust gas temperature at about 20 °C. The flue 13, the fixed support 17, and the round umbrella-shaped wind cap 18 form a flue gas discharge device, and a thermal expansion gap is left between the conical cover 16 and the roof panel 15 for rain shielding.

[0069] The embodiment of the present disclosure reduces the discharge temperature of the flue gas to below 20 °C, deeply recovers the latent heat and sensible heat in the flue gas, and integrates the gas boiler with the waste heat recovery heat pump, making the equipment compact, light in structure, small in floor area, and convenient for modular selection. In addition, it can also improve the energy utilization efficiency, reduce the consumption of natural gas, alleviate the contradiction between the supply and demand of natural gas in China, recover a considerable amount of moisture, reduce the emission of environmental pollutants, and achieve the three goals of energy conservation, water conservation, and emission reduction.

[0070] The series of detailed descriptions listed above are only specific descriptions of the feasible implementation manners of the present disclosure, and they are not intended to limit the protection scope of the present disclosure. Any equivalent implementation manners or modifications made without departing from the technical spirit of the present disclosure should be included within the protection scope of the present disclosure.

[0071] For those skilled in the art, it is obvious that the present disclosure is not limited to the details of the above exemplary embodiments, and the present disclosure can be implemented in other specific forms without departing from the spirit or basic characteristics of the present disclosure. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present disclosure is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present disclosure. Any reference signs in the claims should not be construed as limiting the claimed rights.

[0072] In addition, it should be understood that although this specification is described in terms of embodiments, not every embodiment only contains an independent technical solution. This narrative manner of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A flue gas de - whitening device, characterized in that, Comprising: An energy saver and a condensation heat recovery device installed in the flue; When the boiler burns, flue gas is generated and the flue gas flows through the flue which is connected to the boiler; The energy saver is installed closer to the boiler than the condensation heat recovery device; The flue gas exchanges heat with the energy saver first and then with the condensation heat recovery device in the flue; A heat medium flow channel is installed on the outer peripheral wall of the flue, and the heat medium in the heat medium flow channel exchanges heat with the flue gas; the heat medium flow channel extends along the flue from the boiler until it exceeds the condensation heat recovery device; the heat medium flow channel is connected to the heat medium chamber inside the boiler; the heat medium flows in the heat medium chamber and the heat medium flow channel; a compressor and a heat exchanger are installed close to the flue; refrigerant flows on one side of the heat exchanger, the heat exchanger, the compressor and the condensation heat recovery device are interconnected, and the refrigerant circulates between the heat exchanger, the compressor and the condensation heat recovery device, and the refrigerant exchanges heat with the flue gas in the condensation heat recovery device; Domestic water flows on the other side of the heat exchanger, and the other side of the heat exchanger is also connected to the energy saver. After the domestic water exchanges heat with the refrigerant once in the heat exchanger, it enters the energy saver to exchange heat with the flue gas in the flue for the second time; For small and medium-sized vacuum gas boilers with a heating capacity of 1 ton to 10 tons of steam, 10 grades are formed.

2. An integrated device for a boiler and waste heat recovery, characterized in that, Comprising: A boiler, a flue and a waste heat recovery device, and the waste heat recovery device is a flue gas dewhitening device as described in claim 1; The boiler includes a combustion chamber, a heat medium chamber and a steam chamber. The combustion chamber is connected to the flue. The flue gas generated by the combustion of fuel in the combustion chamber exchanges heat with the heat medium in the heat medium chamber once and then enters the flue. The flue gas exchanges heat with the energy saver first and then with the condensation heat recovery device in the flue; The heat medium in the heat medium chamber exchanges heat with the flue gas and also exchanges heat with the heat generated by the combustion of fuel in the combustion chamber.

3. The integrated boiler and waste heat recovery device according to claim 2, wherein The boiler further includes a blower; The air duct of the blower is connected to the combustion chamber.

4. The integrated boiler and waste heat recovery device according to claim 3, characterized in that The boiler and the waste heat recovery integrated device further include a tubular heat exchange module; The steam chamber is connected to the heat medium chamber; The tubular heat exchange module is installed in the steam chamber, and the water medium flowing in the tubular heat exchange module exchanges heat with the hot steam in the steam chamber.

5. The integrated boiler and waste heat recovery device according to claim 4, characterized in that, Natural gas and air enter the combustion chamber through the blower for combustion to generate high-temperature flue gas; The high-temperature flue gas exchanges heat with the hot water in the heat medium chamber, and the hot water absorbs heat to form high-temperature steam; The high-temperature steam enters the steam chamber and heats the circulating hot water in the tubular heat exchange module; After the high-temperature steam releases heat, it forms condensed water and enters the heat medium chamber to continue to exchange heat with the high-temperature flue gas.

6. The integrated boiler and waste heat recovery device according to claim 4, characterized in that The tubular heat exchange module includes a first tubular heat exchanger and a second tubular heat exchanger; The first tubular heat exchanger and the second tubular heat exchanger are installed in parallel in the steam chamber; The second tubular heat exchanger is connected to the other side of the heat exchanger of the flue gas dewhitening device; The temperature of the hot water flowing out of the second tubular heat exchanger is higher than the temperature of the hot water flowing out of the first tubular heat exchanger.

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