Afterburning water-mixing large-temperature-difference heat exchange unit

Abstract

The utility model discloses an afterburning water-mixing large-temperature-difference heat exchange unit which is characterized by comprising a generator, a condenser, an absorber and an evaporator, and the generator comprises a hot water heat exchange generator and an afterburning heating generator; the return water of the downstream heat users comprises a first return water path and a second return water path; supplied water of an upstream heat source is cooled through the hot water heat exchange generator, a first path of return water is heated through the absorber and the condenser, and the first path of return water and outlet water of the hot water heat exchange generator are converged to form converged water to be output to a downstream heat user; and the second return water is cooled by the evaporator and output to the upstream heat source. Large-temperature-difference heat supply can be carried out in the water mixing heat exchange station, and the temperature of primary return water is reduced on the premise that heat supply parameters of heat consumers are guaranteed; meanwhile, fuel gas energy existing in the heat exchange station is fully utilized, the return water temperature is further reduced, the supply and return water temperature difference is increased, the transmission and distribution energy consumption of a backbone network is reduced, and the fuel gas utilization efficiency is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of heating, and in particular relates to a supplementary combustion type mixed water type large temperature difference heat exchange unit. Background Art

[0002] With the continuous expansion of urban heating areas, heat load demand is rapidly increasing, and the existing pipeline network of centralized heating systems is struggling to meet this demand. To meet heating requirements, it is necessary to increase flow rate or improve temperature differentials. However, increasing flow rate requires re-laying pipes, which is very costly in densely populated cities. Therefore, only by increasing the supply and return water temperature differential can the pipeline network's transmission and distribution capacity be increased while maintaining the same flow rate and meeting the heat load demand. The supply water temperature of centralized heating systems is generally limited by the pressure capacity of the pipeline network and cannot be significantly increased. Therefore, significantly reducing the return water temperature is the primary approach to addressing the current pipeline network transmission and distribution bottleneck. Furthermore, heating systems use natural gas to directly heat the heating network water, which wastes the gas's energy quality. Therefore, there is an urgent need to develop a large temperature differential heat exchanger unit that can reduce the return water temperature while ensuring heating parameters for downstream heat users. At the same time, it can fully utilize the high-quality work capacity of natural gas to further reduce the return water temperature, widen the supply and return water temperature differential, and improve the transmission and distribution capacity of the backbone network. Utility Model Content

[0003] (1) Purpose of the utility model

[0004] The purpose of the utility model is to provide a supplementary combustion type large temperature difference heat exchange unit using gas.

[0005] (2) Technical solution

[0006] In order to solve the above problems, the utility model provides a supplementary combustion type mixed water large temperature difference heat exchange unit, including a generator, a condenser, an absorber, and an evaporator; the generator includes a hot water heat exchange generator and a supplementary combustion heating generator, the condenser includes a condensing heat exchanger, the absorber includes an absorption heat exchanger, and the evaporator includes an evaporation heat exchanger.

[0007] The secondary water return of the downstream heat user includes the first return water and the second return water; the water supply of the upstream heat source is cooled by the hot water heat exchange generator, and the first return water is heated in series through the absorption heat exchanger and the condensation heat exchanger, and merged with the outlet water of the hot water heat exchange generator to form the merged water output to the downstream heat user; the second return water is cooled by the evaporation heat exchanger and output to the upstream heat source.

[0008] To further increase the water supply temperature, a post-fired generator and post-fired condenser can be added. The generator only contains a hot water heat exchange generator. The first-line recovery of downstream users is heated in series through an absorption heat exchanger, a condensing heat exchanger, and a post-fired condensing heat exchanger. The water is then combined with the outlet water of the hot water heat exchange generator and delivered to the downstream heat users.

[0009] In order to improve the efficiency of gas utilization, a flue gas condensing heat exchanger can also be installed at the exhaust point, and the water outlet of the evaporative heat exchanger can be used to recover the low-temperature waste heat of the flue gas and reduce the exhaust temperature.

[0010] (3) Beneficial effects

[0011] The above-mentioned technical solution of the present invention has the following beneficial technical effects: The present invention heats or cools the supply water delivered from the upstream heat source and the return water from the downstream heat users, which is then returned to the upstream heat source or provided to the downstream heat users. Specifically, the low-temperature return water from the downstream heat users is split into two paths: one path is heated to a high temperature and delivered to the downstream heat users along with the supply water cooled by the hot water heat exchange generator. The other path is further cooled in the evaporator before being returned to the upstream heat source as return water. To further lower the return water temperature, supplementary combustion with gas is employed to enhance the cooling capacity of the heat exchanger unit. This allows the return water returning to the upstream heat source to be cooled while still providing high-temperature heating to the downstream heat users, significantly reducing the return water temperature, enabling heat transfer from low to high temperatures, and reducing transmission and distribution energy consumption in the main network. Furthermore, the flue gas condensing heat exchanger deeply recovers waste heat from the flue gas, improving gas utilization efficiency. The present invention enables large temperature differential heating within the heat exchange station, reducing the primary return water temperature while ensuring the heating parameters of the downstream heat users. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a structural diagram of the first embodiment of the supplementary combustion type mixed water type large temperature difference heat exchange unit of the present utility model;

[0013] Figure 2 It is a structural schematic diagram of the second embodiment of the supplementary combustion type mixed water type large temperature difference heat exchange unit of the present invention.

[0014] Reference numerals:

[0015] 1: Generator; 11: First heater; 12: Second heater; 13: First cooler; 2: Second heat pump; 21: Third heater; 22: Second cooler; 3: Reheater; 4: Third heat pump; 40: First generator; 41: First evaporator; 5: Heat exchanger; 51: Second generator.

[0016] 1: Generator; 1': Supplementary combustion generator; 2: Condenser; 2': Supplementary combustion condenser; 3: Absorber; 4: Evaporator; 5: Flue gas condensing heat exchanger; 6: Flue gas condensing pump; 11: Hot water heat exchange generator; 12: Supplementary combustion heating generator; 21: Condensing heat exchanger; 2'1: Supplementary combustion condensing heat exchanger; 31: Absorption heat exchanger; 41: Evaporation heat exchanger; 1-2: Condensation liquid blocking device; 3-4: Evaporation absorption liquid blocking device; 1'-2': Supplementary combustion condensing liquid blocking device. DETAILED DESCRIPTION

[0017] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are merely illustrative and are not intended to limit the scope of the present invention. Furthermore, descriptions of known structures and technologies are omitted in the following description to avoid unnecessary confusion regarding the concepts of the present invention.

[0018] Figure 1 It is a structural schematic diagram of the supplementary combustion type mixed water type large temperature difference heat exchange unit of the first embodiment of the present utility model.

[0019] like Figure 1 As shown, the heat exchange unit includes a generator 1, a condenser 2, an absorber 3, and an evaporator 4. Generator 1 is connected to condenser 2, with condensation-blocking devices 1-2 installed in the channels. Absorber 3 is connected to evaporator 4, with evaporation-absorption-blocking devices 3-4 installed in the channels. Generator 1 houses a hot water heat exchange generator 11 and a supplemental heating generator 12. Condenser 2 houses a condensing heat exchanger 21. Absorber 3 houses an absorption heat exchanger 31. Evaporator 4 houses an evaporation heat exchanger 41.

[0020] The water supply from the upstream heat source is cooled by the hot water heat exchange generator 11. The secondary return water from the downstream heat user includes a first return water path and a second return water path. The first return water is heated in series through the absorption heat exchanger 31 and the condensing heat exchanger 21, and then merges with the output water from the hot water heat exchange generator 11 to form the combined water, which is then output to the downstream heat user. The second return water is cooled by the evaporative heat exchanger 41 and then output to the upstream heat source.

[0021] A flue gas condensation heat exchanger 5 is provided on the exhaust flue of the supplementary combustion heating generator 12. A portion of the water from the evaporation heat exchanger 41 is pumped into the flue gas condensation heat exchanger 5 through a flue gas condensation pump 6 to cool the flue gas.

[0022] Figure 2 It is a structural schematic diagram of a supplementary combustion type mixed water type large temperature difference heat exchange unit according to the second embodiment of the present utility model.

[0023] like Figure 2 As shown, based on the first embodiment, the heat exchange unit also includes a supplemental-fired generator 1' and a supplemental-fired condenser 2'. The supplemental-fired generator 1' is connected to the supplemental-fired condenser 2', and a supplemental-fired condenser liquid blocking device 1'-2' is provided in the channel. A supplemental-fired heating generator 12 is provided within the supplemental-fired generator 1', and a supplemental-fired condensing heat exchanger 2'1 is provided within the supplemental-fired condenser 2'.

[0024] The first return water is heated in series through the absorption heat exchanger 31, the condensing heat exchanger 21 and the supplementary combustion condensing heat exchanger 2'1, and is combined with the outlet water of the hot water heat exchange generator 11 to form combined water that is output to the downstream heat user.

Claims

1. A supplementary combustion type water mixing type large temperature difference heat exchange unit, characterized in that: It includes a generator (1), a condenser (2), an absorber (3), and an evaporator (4); The generator (1) comprises a hot water heat exchange generator (11) and a supplementary combustion heating generator (12); The condenser (2) includes a condensing heat exchanger (21); The absorber (3) includes an absorption heat exchanger (31); The evaporator (4) includes an evaporative heat exchanger (41); The secondary water return of downstream heat users includes the first return water and the second return water; The water supply from the upstream heat source is cooled by the hot water heat exchange generator (11), and the first return water is heated in series by the absorption heat exchanger (31) and the condensation heat exchanger (21) in sequence, and is combined with the outlet water of the hot water heat exchange generator (11) to form combined water and output to the downstream heat user; The second return water is cooled by the evaporative heat exchanger (41) and output to the upstream heat source.

2. The heat exchange unit according to claim 1, characterized in that: It also includes a supplementary firing generator (1') and a supplementary firing condenser (2'); The supplementary combustion heating generator (12) is arranged in the cavity of the supplementary combustion generator (1'), and a supplementary combustion condensing heat exchanger (2'1) is arranged in the cavity of the supplementary combustion condenser (2'); The first return water is sequentially heated in series through the absorption heat exchanger (31), the condensing heat exchanger (21) and the supplementary combustion condensing heat exchanger (2'1), and is then combined with the outlet water of the hot water heat exchange generator (11) to form combined water that is output to downstream heat users.

3. The heat exchange unit according to claim 1 or 2, characterized in that: The generator (1) is communicated with the condenser (2), and a condensation liquid blocking device (1-2) is provided in the channel.

4. The heat exchange unit according to claim 1 or 2, characterized in that: The absorber (3) is communicated with the evaporator (4), and an evaporation absorption liquid blocking device (3-4) is provided in the channel.

5. The heat exchange unit according to claim 2, characterized in that: The afterburning generator (1') is communicated with the afterburning condenser (2'), and a afterburning condenser liquid blocking device (1'-2') is provided in the channel.

6. The heat exchange unit according to claim 1 or 2, characterized in that: Also includes: A flue gas condensing heat exchanger (5) is arranged on the flue gas exhaust duct of the supplementary combustion heating generator (12); The flue gas condensation pump (6) extracts part of the water from the evaporation heat exchanger (41) and enters the flue gas condensation heat exchanger (5) for heating, and then returns to the upstream heat source.

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