Biomass boiler flue gas deep waste heat recovery heat supply unit

Abstract

The utility model discloses a biomass boiler flue gas deep waste heat recovery heat supply unit, and belongs to the technical field of new energy heat supply and waste heat recovery. High-temperature and high-humidity flue gas is respectively fed into a front energy saver and a graded flue gas deep waste heat recovery tower for heat exchange and graded utilization, a washing heat exchange section, a medium-temperature heat exchange section and a low-temperature heat exchange section are respectively arranged in the tower from bottom to top, the flue gas is cooled to 7-35 DEG C, and meanwhile, flue gas pollutants are greatly reduced to near zero emission; the heated water is heated to 60-90 DEG C step by step by using the second heat exchanger, the first heat exchanger, the heat pump and the front-mounted energy saver respectively and is heated to 60-90 DEG C by the waste heat of the flue gas at each stage; a first heat exchanger and a front energy saver are adopted for air inlet of the biomass boiler, and flue gas waste heat of all high-temperature sections is heated to 100-150 DEG C; according to the technical system, deep waste heat recovery of the flue gas of the biomass boiler is achieved, and driving energy consumption and cost are greatly reduced through graded heat exchange.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of biomass boiler flue gas depth waste heat recovery heating unit, belong to new energy heating and waste heat recovery technical field. BACKGROUND

[0002] There are a large amount of water vapor in the flue gas of urban biomass boiler, and its latent heat and sensible heat are all wasted with flue gas. To recover the waste heat of such high-humidity flue gas deeply, the commonly used waste heat utilization methods include: low-low temperature economizer or energy saver with partition, flue gas condensing heat recovery device based on absorption heat pump heat exchange, etc. However, the former has problems of corrosion, high cost of heat exchange materials, etc.; the latter has problems of large amount of driving heat source required by absorption heat pump, high cost leading to long investment recovery period, etc.

[0003] The air for the boiler, process water or return water of heat supply network from outside the plant needs to be heated by high-grade heat energy such as steam, which can be saved by using flue gas waste heat.

[0004] In addition, the flue gas contains a large amount of water vapor and soluble fine particulate matter, so it is necessary to purify deeply and even achieve near-zero emission of flue gas pollutants and substantial "flue gas white" treatment. CONTENT OF THE UTILITY MODEL

[0005] The purpose and task of the utility model are to recover the waste heat of high-temperature and high-humidity flue gas of biomass boiler by using multi-stage heat exchange method, to heat the water of heat supply network, air for the boiler or process water, so as to realize deep waste heat recovery and substantial white elimination treatment of flue gas from the boiler.

[0006] The utility model discloses a specific description is: a kind of biomass boiler flue gas depth waste heat recovery heating unit, the unit is formed flue gas depth waste heat recovery integrated system with auxiliary system for biomass boiler, wherein biomass boiler and auxiliary system include biomass boiler 101, furnace rear flue gas treatment equipment 102, high temperature warm air blower 103, induced draft fan 104, air supply fan 105, it is characterized in that: the flue gas depth waste heat recovery heating and process heating unit including flue gas depth waste heat recovery tower 1, first heat exchanger 2, second heat exchanger 3, third heat exchanger 4, flue gas waste heat warm air blower 5 and front economizer 6, wherein the flue gas depth waste heat recovery tower 1 adopts vertical integral type grading heat exchange structure, it is from below to above respectively washes heat exchange section 12, medium-temperature heat exchange section 15, low-temperature heat exchange section 17, wherein the lower part of washes heat exchange section 12 is flue gas tower bottom pool 11, the upper portion of washes heat exchange section 12 is provided with high-temperature spray device 13, the upper portion of high-temperature spray device 13 is provided with gas-liquid separator 14, the upper portion of gas-liquid separator 14 is medium-temperature heat exchange section 15 for spraying heat exchange of high-humidity flue gas L of medium temperature, the upper portion of medium-temperature heat exchange section 15 is provided with medium-temperature spray device 16, the upper portion of medium-temperature spray device 16 is low-temperature heat exchange section 17 for spraying heat exchange of medium-low-temperature flue gas M, the upper portion of low-temperature heat exchange section 17 is provided with low-temperature spray device 18, the upper portion of low-temperature spray device 18 is provided with flue gas humidity adjusting device 19, the upper portion of flue gas humidity adjusting device 19 is communicated with flue gas outlet section 20, and the low-temperature near-zero emission flue gas N at the flue gas outlet section 20 is communicated with atmosphere;The high-temperature waste heat water outlet of the flue gas tower bottom pool 11 is connected with the high-temperature side inlet of first heat exchanger 2, and the high-temperature side outlet of first heat exchanger 2 is connected with the water inlet of high-temperature spray device 13, the water outlet of gas-liquid separator 14 is connected with the high-temperature side inlet of second heat exchanger 3, the high-temperature side outlet of second heat exchanger 3 is connected with the water inlet of medium-temperature spray device 16, and the high-temperature side outlet of second heat exchanger 3 is also connected with the low-temperature heat source side water inlet of third heat exchanger 4, and the low-temperature heat source side water outlet of third heat exchanger 4 is connected with the water inlet of low-temperature spray device 18;The low-temperature side inlet of second heat exchanger 3 is communicated with the return water pipe of heated return water H, and the low-temperature side outlet of second heat exchanger 3 is connected with the low-temperature side inlet of first heat exchanger 2, and the low-temperature side outlet of first heat exchanger 2 is respectively communicated with the water supply pipe of heated water supply G, connected with the high-temperature heat source side water inlet of third heat exchanger 4, and connected with the water inlet of front economizer 6, the high-temperature heat source side water outlet of third heat exchanger 4 is communicated with the water supply pipe of heated water supply G, and the water outlet of front economizer 6 is respectively communicated with the water supply pipe of heated water supply G, connected with the water inlet of flue gas waste heat warm air blower 5, and the water outlet of flue gas waste heat warm air blower 5 is connected with the low-temperature side inlet of first heat exchanger 2.

[0007] The third heat exchanger 4 adopts a compression heat pump structure, and is provided with a low-temperature heat source heat exchanger 41 and a high-temperature heat source heat exchanger 42. The low-temperature heat source heat exchanger 41 adopts a compression heat pump evaporator structure, and is provided with low-temperature heat source side water inlets and outlets. The high-temperature heat source heat exchanger 42 adopts a compression heat pump condenser structure, and is provided with high-temperature heat source side water inlets and outlets. The high-temperature heat source side inlet is connected with the high-temperature side outlet of the first heat exchanger 2, and the high-temperature heat source side outlet is communicated with the water supply pipe of the heated water G.

[0008] The third heat exchanger 4 adopts an absorption heat pump structure, and is provided with a low-temperature heat source heat exchanger 41 and a high-temperature heat source heat exchanger 42. The low-temperature heat source heat exchanger 41 adopts an absorption heat pump evaporator structure, and is provided with low-temperature heat source side water inlets and outlets. The high-temperature heat source heat exchanger 42 adopts an absorption heat pump condenser and absorber combined structure, and is provided with high-temperature heat source side water inlets and outlets. The high-temperature heat source side inlet is connected with the high-temperature side outlet of the first heat exchanger 2, and the high-temperature heat source side outlet is communicated with the water supply pipe of the heated water G.

[0009] The air inlet of the flue gas waste heat air heater 5 is connected with the air outlet of the air supply fan 105, the air inlet of the air supply fan 105 is communicated with the combustion air A, the air outlet of the flue gas waste heat air heater 5 is connected with the air inlet of the high-temperature air heater 103 through the flue gas preheated air C air pipe, the air outlet of the high-temperature air heater 103 is connected with the air inlet of the biomass boiler 101 through the high-temperature air inlet D air pipe, the high-temperature side inlet of the high-temperature air heater 103 is connected with the main pipe of the high-temperature heat source flow B1, the high-temperature side outlet of the high-temperature air heater 103 is connected with the main pipe of the high-temperature heat source flow B2, the outlet of the original flue gas E of the biomass boiler 101 is connected with the smoke inlet of the post-flue gas treatment device 102, the smoke outlet of the post-flue gas treatment device 102 is connected with the smoke inlet of the induced draft fan 104, the smoke outlet of the induced draft fan 104 is connected with the smoke inlet of the pre-positioned economizer 6 through the original flue gas F air pipe, and the smoke outlet of the pre-positioned economizer 6 is connected with the lateral smoke inlet of the washing and heat exchange section 12 of the flue gas deep waste heat recovery tower 1 through the high-humidity flue gas J air pipe.

[0010] The water inlets and outlets of the pre-positioned economizer 6 and the high-temperature heat source heat exchanger 42 of the third heat exchanger 4 adopt a parallel structure or a series structure. If the series structure is adopted, the water inlet of the pre-positioned economizer 6 is connected with the water outlet of the high-temperature heat source heat exchanger 42.

[0011] The third heat exchanger 4 adopts a partition wall type heat exchanger structure, and is further provided with process water side water inlets and outlets. The process water side inlet is connected with the water inlet pipe of the low-temperature process water flow H1, and the process water side outlet is communicated with the water supply pipe of the heated water G.

[0012] The flue gas tower bottom water pool 11 is further provided with a dosing opening, the dosing opening is connected with the discharge opening of the water quality adjusting device 7, and the water quality adjusting device 7 is further provided with a water quality adjusting agent K feeding opening.

[0013] The washing heat exchange section 12, the medium temperature heat exchange section 15 and the low temperature heat exchange section 17 are vertical counter-flow heat exchange structures composed of flue gas and spraying water, wherein an empty section or a filler structure is used inside.

[0014] The washing heat exchange section 12, the medium temperature heat exchange section 15 and the low temperature heat exchange section 17 adopt single-layer groove tray water distribution structure, groove structure or water distribution structure composed of N layers of spraying structure, wherein N is greater than or equal to 1.

[0015] The flue gas waste heat air heater 5 and the front energy saver 6 adopt fluoroplastic coil heat exchanger, carbon-based material coil heat exchanger, fluoroplastic steel coil heat exchanger, stainless steel heat exchanger or ND steel heat exchanger structure for wind and smoke side corrosion prevention.

[0016] The utility model discloses a high-temperature and high-humidity flue gas of biomass boiler is carried out grading heat recovery, realizes grading utilization, wherein the flue gas waste heat is used for the heating of heated return water, including the heating of heat network return water or process return water etc., respectively passes through second heat exchanger 3, first heat exchanger 2, high temperature heat source heat exchanger 42 and / or front energy saver 6 heating, can usually heat to 60~70 DEG C or higher, sends to downstream again.The flue gas waste heat can also be used as the air preheating of biomass boiler to save the high-grade heat energy of original high-temperature air heater 103, at this time, the source of high-temperature heat source water of flue gas waste heat air heater 5 is the outlet water of front energy saver 6 or the low-temperature side outlet water of first heat exchanger 2, and the outlet water of high-temperature heat source water of flue gas waste heat air heater 5 returns the low-temperature side inlet of first heat exchanger 2, wherein the front energy saver 6 can switch between the air preheating and the heating of heated return water, or simultaneously carry out.In addition, the patent can finally reduce the flue gas temperature to 7~35 DEG C, realizes deep waste heat recovery and near-zero emission of pollutants. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is the system schematic diagram of the utility model.

[0018] Figure 1 The numbers and names of various components are as follows.

[0019] The flue gas deep waste heat recovery tower 1, the first heat exchanger 2, the second heat exchanger 3, the third heat exchanger 4, the flue gas waste heat air heater 5, the front energy economizer 6, the water quality adjusting device 7, the flue gas tower bottom water pool 11, the flue gas inlet pipe of the washing heat exchange section 12 are communicated, the washing heat exchange section 12, the high-temperature spraying device 13, the gas-liquid separator 14, the medium-temperature heat exchange section 15, the medium-temperature spraying device 16, the low-temperature heat exchange section 17, the low-temperature spraying device 18, the flue gas humidity adjusting device 19, the flue gas outlet section 20, the low-temperature heat source heat exchanger 41, the high-temperature heat source heat exchanger 42, the biomass boiler 101, the post-furnace flue gas treatment equipment 102, the high-temperature air heater 103, the induced draft fan 104, the supply fan 105, the combustion air A, the high-temperature heat source inflow B1, the high-temperature heat source outflow B2, the flue gas preheated air C, the high-temperature air inlet D, the original flue gas E, the original flue gas discharge F, the heated water supply G, the heated water return H, the high-humidity flue gas J, the water quality adjusting agent K, the medium-temperature high-humidity flue gas L, the medium-low-temperature flue gas M and the low-temperature near-zero emission flue gas N. DETAILED DESCRIPTION

[0020] Figure 1 The system schematic diagram and the embodiment of the utility model are as follows.

[0021] The specific embodiment 1 of the utility model is as follows.

[0022] The utility model discloses a specific description is: a kind of biomass boiler flue gas depth waste heat recovery heating unit, the unit is formed flue gas depth waste heat recovery integrated system with auxiliary system for biomass boiler, wherein biomass boiler and auxiliary system include biomass boiler 101, furnace rear flue gas treatment equipment 102, high temperature warm air blower 103, induced draft fan 104, air supply fan 105, it is characterized in that: the flue gas depth waste heat recovery heating and process heating unit including flue gas depth waste heat recovery tower 1, first heat exchanger 2, second heat exchanger 3, third heat exchanger 4, flue gas waste heat warm air blower 5 and front economizer 6, wherein the flue gas depth waste heat recovery tower 1 adopts vertical integral type grading heat exchange structure, it is from below to above respectively washes heat exchange section 12, medium-temperature heat exchange section 15, low-temperature heat exchange section 17, wherein the lower part of washes heat exchange section 12 is flue gas tower bottom pool 11, the upper portion of washes heat exchange section 12 is provided with high-temperature spray device 13, the upper portion of high-temperature spray device 13 is provided with gas-liquid separator 14, the upper portion of gas-liquid separator 14 is medium-temperature heat exchange section 15 for spraying heat exchange of high-humidity flue gas L, the upper portion of medium-temperature heat exchange section 15 is provided with medium-temperature spray device 16, the upper portion of medium-temperature spray device 16 is low-temperature heat exchange section 17 for spraying heat exchange of medium-low-temperature flue gas M, the upper portion of low-temperature heat exchange section 17 is provided with low-temperature spray device 18, the upper portion of low-temperature spray device 18 is provided with flue gas humidity adjusting device 19, the upper portion of flue gas humidity adjusting device 19 is communicated with flue gas outlet section 20, and the low-temperature near-zero emission flue gas N at the flue gas outlet section 20 is communicated with atmosphere;The high-temperature waste heat water outlet of the flue gas tower bottom pool 11 is connected with the high-temperature side inlet of first heat exchanger 2, the high-temperature side outlet of first heat exchanger 2 is connected with the water inlet of high-temperature spray device 13, the water outlet of gas-liquid separator 14 is connected with the high-temperature side inlet of second heat exchanger 3, the high-temperature side outlet of second heat exchanger 3 is connected with the water inlet of medium-temperature spray device 16, the high-temperature side outlet of second heat exchanger 3 is also connected with the low-temperature heat source side water inlet of third heat exchanger 4, and the low-temperature heat source side water outlet of third heat exchanger 4 is connected with the water inlet of low-temperature spray device 18;The low-temperature side inlet of second heat exchanger 3 is communicated with the return water pipe of heated return water H, the low-temperature side outlet of second heat exchanger 3 is connected with the low-temperature side inlet of first heat exchanger 2, the low-temperature side outlet of first heat exchanger 2 is respectively communicated with the water supply pipe of heated water supply G, connected with the high-temperature heat source side water inlet of third heat exchanger 4, connected with the water inlet of front economizer 6, the high-temperature heat source side water outlet of third heat exchanger 4 is communicated with the water supply pipe of heated water supply G, and the water outlet of front economizer 6 is respectively communicated with the water supply pipe of heated water supply G, connected with the water inlet of flue gas waste heat warm air blower 5, and the water outlet of flue gas waste heat warm air blower 5 is connected with the low-temperature side inlet of first heat exchanger 2.

[0023] The third heat exchanger 4 adopts a compression heat pump structure, and is provided with a low-temperature heat source heat exchanger 41 and a high-temperature heat source heat exchanger 42. The low-temperature heat source heat exchanger 41 adopts a compression heat pump evaporator structure, and is provided with low-temperature heat source side water inlets and outlets. The high-temperature heat source heat exchanger 42 adopts a compression heat pump condenser structure, and is provided with high-temperature heat source side water inlets and outlets. The high-temperature heat source side inlet is connected with the high-temperature side outlet of the first heat exchanger 2, and the high-temperature heat source side outlet is communicated with the water supply pipe of the heated water G.

[0024] The third heat exchanger 4 adopts an absorption heat pump structure, and is provided with a low-temperature heat source heat exchanger 41 and a high-temperature heat source heat exchanger 42. The low-temperature heat source heat exchanger 41 adopts an absorption heat pump evaporator structure, and is provided with low-temperature heat source side water inlets and outlets. The high-temperature heat source heat exchanger 42 adopts an absorption heat pump condenser and absorber combined structure, and is provided with high-temperature heat source side water inlets and outlets. The high-temperature heat source side inlet is connected with the high-temperature side outlet of the first heat exchanger 2, and the high-temperature heat source side outlet is communicated with the water supply pipe of the heated water G.

[0025] The air inlet of the flue gas waste heat air heater 5 is connected with the air outlet of the air supply fan 105, the air inlet of the air supply fan 105 is communicated with the combustion air A, the air outlet of the flue gas waste heat air heater 5 is connected with the air inlet of the high-temperature air heater 103 through the flue gas preheating air C air pipe, the air outlet of the high-temperature air heater 103 is connected with the air inlet of the biomass boiler 101 through the high-temperature air inlet D air pipe, the high-temperature side inlet of the high-temperature air heater 103 is connected with the main pipe of the high-temperature heat source flow B1, the high-temperature side outlet of the high-temperature air heater 103 is connected with the main pipe of the high-temperature heat source flow B2, the outlet of the original flue gas E of the biomass boiler 101 is connected with the smoke inlet of the post-flue gas treatment device 102, the smoke outlet of the post-flue gas treatment device 102 is connected with the smoke inlet of the induced draft fan 104, the smoke outlet of the induced draft fan 104 is connected with the smoke inlet of the pre-positioned economizer 6 through the original flue gas F air pipe, and the smoke outlet of the pre-positioned economizer 6 is connected with the lateral smoke inlet of the washing and heat exchange section 12 of the flue gas deep waste heat recovery tower 1 through the high-humidity flue gas J air pipe.

[0026] The water inlets and outlets of the pre-positioned economizer 6 and the high-temperature heat source heat exchanger 42 of the third heat exchanger 4 adopt a parallel structure or a series structure. If the series structure is adopted, the water inlet of the pre-positioned economizer 6 is connected with the water outlet of the high-temperature heat source heat exchanger 42.

[0027] The third heat exchanger 4 adopts a partition wall type heat exchanger structure, and is further provided with process water side water inlets and outlets. The process water side inlet is connected with the water inlet pipe of the low-temperature process water flow H1, and the process water side outlet is communicated with the water supply pipe of the heated water G.

[0028] The flue gas tower bottom water pool 11 is further provided with a dosing opening, the dosing opening is connected with the discharge opening of the water quality adjusting device 7, and the water quality adjusting device 7 is further provided with a water quality adjusting agent K feeding opening.

[0029] The washing heat exchange section 12, the medium temperature heat exchange section 15 and the low temperature heat exchange section 17 are vertical counter-flow heat exchange structures composed of flue gas and spraying water, wherein an empty section or a filler structure is used inside.

[0030] The washing heat exchange section 12, the medium temperature heat exchange section 15 and the low temperature heat exchange section 17 adopt single-layer groove tray water distribution structure, groove structure or water distribution structure composed of N layers of spraying structure, wherein N is greater than or equal to 1.

[0031] The flue gas waste heat air heater 5 and the front energy economizer 6 adopt fluorine plastic coil heat exchanger, carbon-based material coil heat exchanger, fluorine plastic steel coil heat exchanger, stainless steel heat exchanger or ND steel heat exchanger structure with wind and smoke side corrosion resistance.

[0032] It should be noted that the utility model provides a flue gas waste heat recovery integrated unit structure to realize deep condensation heat recovery of boiler flue gas and to be used for heating and humidifying boiler air inlet and heating heated water, according to the overall solution, different specific implementation measures and different structure specific implementation devices can be used, the above specific implementation mode is only one of them, any other similar simple transformation mode, for example, increasing or reducing one or two levels in the multi-stage heat exchanger, simple adjustment of the series or parallel relationship between the levels on the heated water side, using different heat exchange element structures and simple transformation, or simple adjustment of waste heat water inlet and outlet water parameters and grading number, or the transformation mode that ordinary professionals can think of, or the same or similar structure is applied to different flue gas or exhaust air types and other similar application occasions, all fall within the protection scope of the utility model.

Claims

1. A biomass boiler flue gas deep waste heat recovery heating unit, which is matched with a biomass boiler and auxiliary system to form a flue gas deep waste heat recovery integrated system, wherein the biomass boiler and auxiliary system comprises a biomass boiler (101), a post-furnace flue gas treatment device (102), a high-temperature warm air blower (103), an induced draft fan (104), and a forced draft fan (105), and the unit is characterized in that: The flue gas deep waste heat recovery heating and process heating unit comprises a flue gas deep waste heat recovery tower (1), a first heat exchanger (2), a second heat exchanger (3), a third heat exchanger (4), a flue gas waste heat air heater (5) and a pre-energizer (6), wherein the flue gas inlet of the pre-energizer (6) is connected with the flue gas outlet of the induced draft fan (104) through the flue gas pipe of the original flue gas (F), the flue gas outlet of the pre-energizer (6) is connected with the flue gas inlet of the flue gas deep waste heat recovery tower (1) through the flue gas pipe of the high-humidity flue gas (J), the flue gas deep waste heat recovery tower (1) adopts a vertical integral type staged heat exchange structure, which comprises a washing heat exchange section (12), a medium-temperature heat exchange section (15) and a low-temperature heat exchange section (17) from bottom to top, wherein the lower part of the washing heat exchange section (12) is a flue gas tower bottom pool (11), the upper part of the washing heat exchange section (12) is provided with a high-temperature spraying device (13), the upper part of the high-temperature spraying device (13) is provided with a gas-liquid separator (14), the upper part of the gas-liquid separator (14) is the medium-temperature heat exchange section (15) for spraying heat exchange of the medium-temperature high-humidity flue gas (L), the upper part of the medium-temperature heat exchange section (15) is provided with a medium-temperature spraying device (16), the upper part of the medium-temperature spraying device (16) is the low-temperature heat exchange section (17) for spraying heat exchange of the medium-low-temperature flue gas (M), the upper part of the low-temperature heat exchange section (17) is provided with a low-temperature spraying device (18), the upper part of the low-temperature spraying device (18) is provided with a flue gas humidity adjusting device (19), the upper part of the flue gas humidity adjusting device (19) is communicated with a flue gas outlet section (20), and the low-temperature near-zero emission flue gas (N) at the flue gas outlet of the flue gas outlet section (20) is communicated with the atmosphere; the high-temperature waste heat water outlet of the flue gas tower bottom pool (11) is connected with the high-temperature side inlet of the first heat exchanger (2), the high-temperature side outlet of the first heat exchanger (2) is connected with the water inlet of the high-temperature spraying device (13), the water outlet of the gas-liquid separator (14) is connected with the high-temperature side inlet of the second heat exchanger (3), the high-temperature side outlet of the second heat exchanger (3) is connected with the water inlet of the medium-temperature spraying device (16), the high-temperature side outlet of the second heat exchanger (3) is also connected with the low-temperature heat source side water inlet of the third heat exchanger (4), and the low-temperature heat source side water outlet of the third heat exchanger (4) is connected with the water inlet of the low-temperature spraying device (18); the low-temperature side inlet of the second heat exchanger (3) is communicated with the return water pipe of the heated return water (H), the low-temperature side outlet of the second heat exchanger (3) is connected with the low-temperature side inlet of the first heat exchanger (2), the low-temperature side outlet of the first heat exchanger (2) is respectively communicated with the water supply pipe of the heated water supply (G), connected with the high-temperature heat source side water inlet of the third heat exchanger (4) and connected with the water inlet of the pre-energizer (6), the high-temperature heat source side water outlet of the third heat exchanger (4) is communicated with the water supply pipe of the heated water supply (G), the water outlet of the pre-energizer (6) is respectively communicated with the water supply pipe of the heated water supply (G) and connected with the water inlet of the flue gas waste heat air heater (5), and the water outlet of the flue gas waste heat air heater (5) is connected with the low-temperature side inlet of the first heat exchanger (2).

2. A biomass boiler flue gas deep heat recovery heating unit according to claim 1, characterized in that The third heat exchanger (4) adopts an electric compression heat pump structure and is provided with a low-temperature heat source heat exchanger (41) and a high-temperature heat source heat exchanger (42), wherein the low-temperature heat source heat exchanger (41) adopts a compression heat pump evaporator structure and is provided with low-temperature heat source side water inlets and outlets; the high-temperature heat source heat exchanger (42) adopts a compression heat pump condenser structure and is provided with high-temperature heat source side water inlets and outlets, wherein the high-temperature heat source side inlet is connected with the high-temperature side outlet of the first heat exchanger (2), and the high-temperature heat source side outlet is communicated with a water supply pipe of the heated water (G).

3. A biomass boiler flue gas deep heat recovery heating unit according to claim 1, characterized in that The third heat exchanger (4) adopts an absorption heat pump structure and is provided with a low-temperature heat source heat exchanger (41) and a high-temperature heat source heat exchanger (42), wherein the low-temperature heat source heat exchanger (41) adopts an absorption heat pump evaporator structure and is provided with low-temperature heat source side water inlets and outlets; the high-temperature heat source heat exchanger (42) adopts an absorption heat pump condenser and absorber combined structure and is provided with high-temperature heat source side water inlets and outlets, wherein the high-temperature heat source side inlet is connected with the high-temperature side outlet of the first heat exchanger (2), and the high-temperature heat source side outlet is communicated with a water supply pipe of the heated water (G).

4. A biomass boiler flue gas deep heat recovery heating unit according to claim 1, characterized in that The air inlet of the flue gas waste heat air heater (5) is connected with the air outlet of the air supply fan (105), the air inlet of the air supply fan (105) is communicated with the combustion air (A), the air outlet of the flue gas waste heat air heater (5) is connected with the air inlet of the high-temperature air heater (103) through an air pipe of the flue gas preheated air (C), the air outlet of the high-temperature air heater (103) is connected with the air inlet of the biomass boiler (101) through an air pipe of the high-temperature air (D), the high-temperature side inlet of the high-temperature air heater (103) is connected with a main pipe of the high-temperature heat source flow (B1), the high-temperature side outlet of the high-temperature air heater (103) is connected with a main pipe of the high-temperature heat source return flow (B2), the outlet of the original flue gas (E) of the biomass boiler (101) is connected with the flue gas inlet of the post-boiler flue gas treatment device (102), the flue gas outlet of the post-boiler flue gas treatment device (102) is connected with the flue gas inlet of the induced draft fan (104), the flue gas outlet of the induced draft fan (104) is connected with the flue gas inlet of the pre-positioned economizer (6) through an air pipe of the original flue gas (F), and the flue gas outlet of the pre-positioned economizer (6) is connected with the lateral flue gas inlet of the washing and heat exchange section (12) of the flue gas deep waste heat recovery tower (1) through an air pipe of the high-humidity flue gas (J).

5. A biomass boiler flue gas deep heat recovery heating unit as claimed in claim 4 in combination with claim 2 or claim 3, characterized in that The water inlets and outlets of the pre-positioned economizer (6) and the high-temperature heat source heat exchanger (42) of the third heat exchanger (4) adopt a parallel structure or a series structure; if the series structure is adopted, the water inlet of the pre-positioned economizer (6) is connected with the water outlet of the high-temperature heat source heat exchanger (42).

6. A biomass boiler flue gas deep heat recovery heating unit according to claim 1, characterized in that The third heat exchanger (4) adopts a partition wall heat exchanger structure, and is further provided with process water side water inlets and outlets, wherein the process water side inlet is connected with a water inlet pipe of the low-temperature process water (H1), and the process water side outlet is communicated with a water supply pipe of the heated water (G).

7. A biomass boiler flue gas deep heat recovery heating unit according to claim 1, characterized in that The flue gas tower bottom water pool (11) is further provided with a dosing port, the dosing port is connected with a discharge port of the water quality adjusting device (7), and the water quality adjusting device (7) is further provided with a water quality adjusting agent (K) feeding port.

8. A biomass boiler flue gas deep heat recovery heating unit according to claim 1, characterized in that The washing heat exchange section (12), the medium temperature heat exchange section (15) and the low temperature heat exchange section (17) are countercurrent heat exchange structures arranged vertically and composed of flue gas and spraying water, wherein an empty section or a filler structure is used inside.

9. A biomass boiler flue gas deep heat recovery heating unit according to claim 1, characterized in that The washing heat exchange section (12), the medium temperature heat exchange section (15) and the low temperature heat exchange section (17) adopt single-layer slot tray water distribution structure, slot structure or water distribution structure composed of N layers of spraying structure, wherein N is greater than or equal to 1.

10. A biomass boiler flue gas deep heat recovery heating unit according to claim 1, characterized in that The flue gas waste heat air heater (5) and the front energy-saving device (6) adopt fluoroplastic coil heat exchanger, carbon-based material coil heat exchanger, fluoroplastic steel coil heat exchanger, stainless steel heat exchanger or ND steel heat exchanger structure on the air and flue gas side.

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