Heat pump unit utilizing fuel cell power generation waste heat

Abstract

The utility model discloses a heat pump unit utilizing fuel cell power generation waste heat, which comprises a generator set, a heat pump unit, a heat exchanger set and a hot water storage tank, waste gas of the generator set is introduced into the heat exchanger set through a pipeline to exchange heat with water, heated hot water is introduced into the hot water storage tank from the heat exchanger set, and the hot water is stored in the hot water storage tank. A refrigerant in an indoor heat exchanger of the heat pump unit exchanges heat with water, and the heated water is communicated with the hot water storage tank through a pipeline. According to the utility model, the fuel cell generator set and the heat pump set are well combined, so that the utilization rate of fuel cell power generation waste heat resources is greatly improved, and the energy consumption of the heat pump set is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to refrigeration technical field especially relates to a kind of heat pump unit using fuel cell power generation waste heat. BACKGROUND

[0002] With the increasing consumption of fossil energy, energy crisis and environmental pollution problems are increasingly significant. Solid oxide fuel cell (Solid Oxide Fuel Cell, SOFC) can convert chemical energy in fuel into electrical energy directly through electrochemical reaction, reducing the intermediate energy loss, which is a clean and efficient power generation equipment, with working temperature of 600-800 ℃, high power generation efficiency, strong reliability, wide fuel adaptability, low emission and low noise and other advantages. As a kind of clean and efficient energy utilization mode, distributed energy system with fuel cell cogeneration as the core can alleviate energy crisis to a certain extent.

[0003] Solid oxide fuel cell will generate a large amount of waste heat in the process of power generation, which will greatly improve the energy utilization efficiency of fuel cell when combined with heat pump water heater unit. Chinese patent application CN114400351A discloses a device for generating electricity by using natural gas, charging energy storage battery pack, and providing power for heat pump unit. However, this power generation device uses proton exchange membrane fuel cell, and its electrolyte material can only conduct H+, so its fuel must be hydrogen gas with purity of 99.999% or above, and noble metal catalyst (platinum-based, ruthenium-based catalyst) is needed for multi-stage reforming of natural gas to obtain pure hydrogen gas during reaction process, resulting in complex system structure process and greatly increased production cost. Moreover, a large amount of waste heat generated by power generation device is only used for domestic hot water, and has not been combined with heat pump unit well to reduce the energy consumption of heat pump system. UTILITY MODEL CONTENTS

[0004] The utility model provides a kind of heat pump unit using fuel cell power generation waste heat, to solve the technical problem of reducing the energy consumption of heat pump unit.

[0005] The utility model provides a kind of heat pump unit using fuel cell power generation waste heat, including generator set and heat pump unit, further including a heat exchanger group and a hot water storage tank, the exhaust gas of the generator set is introduced into the heat exchanger group with water heat exchange by pipeline, and the hot water after heating is introduced into the hot water storage tank from the heat exchanger, the refrigerant in the indoor heat exchanger of the heat pump unit exchanges heat with water, and the heated water is communicated with the hot water storage tank by pipeline.

[0006] Preferably, the reaction stack of the generator set uses solid oxide fuel cell stack.

[0007] In an embodiment, the heat exchanger group is composed of a first heat exchanger and a second heat exchanger, and the generator group includes a combustor, a fuel gas heat exchanger, an air heat exchanger, a reformer, a fuel supply unit, an air supply unit, and a solid oxide fuel cell stack, etc., the high-temperature flue gas of the combustor is communicated with the fuel gas heat exchanger and the air heat exchanger through pipes respectively, the exhaust gas discharged from the fuel gas heat exchanger is introduced into the first heat exchanger, and the exhaust gas discharged from the air heat exchanger is introduced into the second heat exchanger.

[0008] Preferably, the combustor is further communicated with the air inlet pipe of the first heat exchanger through a first bypass and with the air inlet pipe of the second heat exchanger through a second bypass, and the first bypass and the second bypass are each provided with an electric valve.

[0009] The heat pump unit includes a compressor, an indoor heat exchanger, a four-way reversing valve, an electronic expansion valve, and an outdoor heat exchanger, and the water outlet pipe of the indoor heat exchanger is communicated with the hot water storage tank.

[0010] Preferably, the exhaust gas discharged from the heat exchanger group is introduced into the outdoor heat exchanger for defrosting and heat exchange with refrigerant.

[0011] Preferably, the first heat exchanger, the second heat exchanger, and the indoor heat exchanger are all double-pipe heat exchangers.

[0012] In the generator group, fuel gas is communicated with the fuel gas heat exchanger and the combustor through pipes respectively, and air is communicated with the air heat exchanger and the combustor through pipes respectively, the preheated fuel gas discharged from the fuel gas heat exchanger enters the fuel reformer for reforming treatment, and then, together with the air preheated by the air heat exchanger, performs an electrochemical reaction in the reaction stack of the generator group to generate electricity, and the exhaust gas generated by the electrochemical reaction is introduced into the combustor.

[0013] Preferably, the generator group further includes a power distribution module for charging the energy storage battery group, or supplying power to the heat pump unit or other loads through an inverter, and / or integrating the generated power into the power grid.

[0014] Further, the utility model also includes a control module, the control module includes:

[0015] A power distribution control module for monitoring and adjusting the power consumption conditions of each power load;

[0016] A power distribution control module for monitoring and adjusting the power consumption conditions of each power load;

[0017] A heat pump control module for monitoring the hot water temperature, pipe pressure, fan speed, and refrigerant flow rate;

[0018] A hot flue gas recovery control module is used for detecting the temperature and flow of the hot flue gas and the tail gas, detecting and adjusting the temperature of the hot water.

[0019] Compared with the prior art, the utility model has the following beneficial effects:

[0020] 1. The waste heat of the fuel cell power generation equipment is recovered, and the utilization rate of the waste heat resource of the fuel cell power generation is greatly improved.

[0021] 2. By increasing the heat exchanger group and the hot water storage tank between the generator set and the heat pump unit, the fuel cell power generation waste heat can be directly supplied to the indoor hot water, which not only improves the utilization of the power generation waste heat, but also reduces the energy consumption of the heat pump unit.

[0022] 3. The generator set uses solid oxide fuel cell stack power generation, does not need to use noble metal catalyst for multi-stage reforming to remove CO, greatly reduces the production manufacturing cost and system structure process complexity.

[0023] 4. The power output distribution is complete and reasonable, so that the fuel cell power generation efficiency is maximized, the excess power generation is connected to the power grid, and the deep peak regulation and power supply pressure relief of the power grid are realized. BRIEF DESCRIPTION OF DRAWINGS

[0024] The utility model will be described in detail below in combination with the drawings and specific embodiments, in which:

[0025] Figure 1 is the system diagram of an embodiment of the utility model;

[0026] Figure 2 is the schematic diagram of the control module of the utility model.

[0027] Among them:

[0028] 1 generator set, 11 fuel gas heat exchanger, 12 fuel reformer, 13 burner, 14 air heat exchanger, 15 solid oxide fuel cell stack, 16 electric valve, 17 first bypass, 18 second bypass;

[0029] 2 heat pump unit, 21 compressor, 22 four-way valve, 23 indoor heat exchanger, 24 electronic expansion valve, 25 outdoor heat exchanger;

[0030] 3 power distribution module, 31 inverter, 32 energy storage battery pack, 33 other electric load;

[0031] 4 power grid;

[0032] 5 hot water storage tank;

[0033] 6 first heat exchanger;

[0034] 7 second heat exchanger;

[0035] 8 control module. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical scheme and advantages of the utility model more clear, the following will make a detailed description of the utility model combining with the drawings and examples. It should be understood that the following specific examples are only used to explain the utility model, and do not limit the utility model.

[0037] The terms used in the specification are only for describing the specific embodiments, and are not intended to limit the utility model. Unless otherwise specified, the relative arrangement, numerical expression and numerical value of the components and steps set forth in these examples do not limit the protection scope of the utility model.

[0038] The technologies, methods and devices known to those skilled in the relevant art are not discussed in detail in the specification, but should be considered as part of the specification in appropriate cases. Any specific value in the specification should be interpreted as merely exemplary, and does not constitute a limitation on the utility model.

[0039] For ease of description, the terms used in the specification to describe the position, such as "above", "left", "front" and the like, are only used to describe the spatial positional relationship of a component with other components in the illustrated embodiment, and the relative position will change when the position of the component is placed, therefore the positional relationship of the embodiment of the drawings should not limit the utility model.

[0040] In addition, it should be noted that the use of "first", "second" and the like in the specification is only to distinguish similar components, and there is no sequence, therefore it should not be understood as limiting the scope of protection of the utility model.

[0041] The concept of the utility model is to build an intermediate structure between the generator set and the heat pump unit, so as to recover the waste heat generated by the generator set, directly supply heat to the indoor through the heat pump unit and defrost the outdoor heat exchanger, or exchange heat with the outdoor heat exchanger, so as to achieve the purpose of reducing the energy consumption of the heat pump unit.

[0042] The utility model uses a solid oxide fuel cell using natural gas as fuel, and the electrolyte material uses yttria-stabilized zirconia (8YSZ), which has good oxygen ion conductivity, so the fuel can be hydrogen, carbon monoxide and natural gas, coal gas, biomass gas and other hydrocarbon fuels. After preheating and reforming, natural gas can be directly introduced into the solid oxide fuel cell stack for power generation, without using precious metal catalyst for multi-stage reforming to remove CO, greatly reducing the production cost and system complexity.

[0043] AsFigure 1 As shown in the utility model, the heat pump unit using the waste heat of fuel cell power generation comprises a power generating set 1 and a heat pump unit 2. The power generating set 1 comprises a fuel gas heat exchanger 11, a fuel reformer 12, a burner 13, an air heat exchanger 14 and a solid oxide fuel cell stack 15. The fuel gas is communicated with the fuel gas heat exchanger 11 and the burner 13 through pipes respectively, and the air is communicated with the air heat exchanger 14 and the burner 13 through pipes respectively. In the starting stage, the electric valve 16 is opened to make the fuel gas and the air burn in the combustion chamber 13, the high-temperature flue gas generated by the burning is introduced into the fuel gas heat exchanger and the air heat exchanger respectively to preheat the fuel gas and the air, the preheated fuel gas discharged from the fuel gas heat exchanger is introduced into the fuel reformer 12 for reforming treatment, and then, together with the air preheated by the air heat exchanger, the fuel gas is subjected to electrochemical reaction in the solid oxide fuel cell stack 15 of the power generating set to generate electricity, and the waste gas generated by the electrochemical reaction is introduced into the burner 13. The burner is communicated with the fuel gas heat exchanger 11 and the air heat exchanger 14 through pipes respectively to provide the heat source required for preheating for the two heat exchangers.

[0044] The fuel cell used in the utility model is a solid oxide fuel cell with wide fuel applicability, the steps of removing CO in multiple stages by natural gas reforming are reduced, the use of noble metal catalyst is reduced, and the cost of the heat pump system for generating electricity by the proton exchange membrane fuel cell is reduced by 15%.

[0045] The heat pump unit 2 comprises a compressor 21, a four-way valve 22 (only schematically shown in the drawing, and the specific flow path is not drawn), an indoor heat exchanger 23, an electronic expansion valve 24 and an outdoor heat exchanger 25. In the heating mode, the high-temperature and high-pressure refrigerant gas discharged from the compressor 1 is introduced into the indoor heat exchanger 23, the indoor heat exchanger adopts a double-pipe heat exchanger, the fluid heated in the double pipe is water, the refrigerant discharged from the indoor heat exchanger 23 is introduced into the outdoor heat exchanger 25 after being cooled and decompressed by the electronic expansion valve 24, the refrigerant is gasified in the outdoor heat exchanger, and then returns to the compressor for circulation. In this embodiment, the outdoor heat exchanger adopts a finned heat exchanger.

[0046] The utility model still includes a heat exchanger group and a hot water storage tank 5, the heat exchanger group is made up of the first heat exchanger 6 and the second heat exchanger 7 in this embodiment. The exhaust gas discharged from the fuel gas heat exchanger 11 is introduced into the first heat exchanger 6 through a pipe, and the exhaust gas discharged from the air heat exchanger is introduced into the second heat exchanger 7 through a pipe. The fluid heated in the first heat exchanger and the second heat exchanger is water, and the heated water is introduced into the hot water storage tank 5 for storage respectively. In this embodiment, the first heat exchanger and the second heat exchanger both adopt double-pipe heat exchangers.

[0047] The hot water exchanged with the indoor heat exchanger is introduced into the hot water storage tank 5.

[0048] The utility model discloses a solid oxide fuel cell and heat pump unit are combined, realize user's heat and power cogeneration. Fuel cell power generation drives heat pump unit work, and the waste heat of fuel cell power generation is recovered simultaneously, and the recovery heat is not only used to produce hot water, but also can be used for accelerating the gasification of refrigerant in outdoor heat exchanger or defrosting outdoor heat exchanger, and then improve the use performance of heat pump unit. The energy utilization rate of fuel cell of the utility model reaches 90% or above.

[0049] When the generator set starts, first, open the electric valve 16 on the fuel gas delivery pipeline and air supply pipeline, make the natural gas burn steadily in the burner 13, the high-temperature flue gas produced by burning is introduced into the fuel gas heat exchanger 11 and the air heat exchanger 14 respectively, the low-temperature (25℃) fuel gas and air exchange heat with the hot flue gas in the fuel gas heat exchanger 11 and the air heat exchanger 13 respectively, the preheated air directly enters the cathode of the solid oxide fuel reaction cell 15, and the preheated natural gas first enters the fuel reformer 12 to be reformed into hydrogen (H2) and carbon monoxide (CO), the natural gas reforming adopts the nickel-based catalyst with a relatively low price, the reformed fuel gas directly enters the anode of the reaction cell 15, and then, under the action of hot air and fuel, the reaction cell is heated to a certain temperature, and at the same time, the cell is lifted to the working temperature for stable power generation by combining the heat generated by the electric discharge of the electrochemical reaction.

[0050] When the reaction cell generates part of the incompletely reacted combustible gas during stable power generation, the combustible gas is introduced into the burner 13 for combustion, and then part of the high-temperature flue gas is introduced into the fuel gas heat exchanger and the air heat exchanger as a heat source, the heat-exchanged hot flue gas is introduced into the first heat exchanger 6 and the second heat exchanger 7 respectively and exchanges heat with water, and the hot water from the first heat exchanger and the second heat exchanger is stored in the hot water storage tank 5. The tail gas (about 50℃) discharged from the first heat exchanger and the second heat exchanger can be introduced into the outdoor heat exchanger to accelerate the gasification of the refrigerant, so as to adjust the temperature of the outdoor heat exchanger and improve the use performance of the heat pump. The tail gas recovered from the first heat exchanger and the second heat exchanger can also be used for defrosting the outdoor heat exchanger.

[0051] In addition, according to the combustion condition in the burner, part of the high-temperature flue gas can be introduced into the first heat exchanger to heat water by adjusting the opening degree of the electric valve 16 on the first bypass 17, and part of the high-temperature flue gas can be introduced into the second heat exchanger to heat water by adjusting the opening degree of the electric valve 16 on the second bypass 18.

[0052] When the heat pump unit is used for heating, the electricity generated by the generator set drives the heat pump unit to work, and the refrigerant becomes high-temperature and high-pressure gaseous refrigerant under the action of the compressor 21, and then enters the indoor heat exchanger (acting as a condenser) to exchange heat with water, the generated hot water flows into the hot water storage tank 5 for storage, and the refrigerant is cooled by the water to become low-temperature liquid refrigerant, and then enters the electronic expansion valve 24 to become low-temperature and low-pressure liquid, and then absorbs the heat of the environment through the outdoor heat exchanger to evaporate into gaseous refrigerant, and finally returns to the compressor to complete a cycle. The hot water in the hot water storage tank 5 can be connected to the indoor terminal device (not shown in the figure) through a pipeline to supply heat to the indoor. When the heating load is not large, the hot water in the hot water storage tank can be used to directly heat the indoor, at this time the heat pump unit can be stopped, and the power consumption is reduced.

[0053] When the heat pump unit is used for cooling, the electricity generated by the generator set drives the heat pump unit to work, and the refrigerant becomes high-temperature and high-pressure gaseous refrigerant under the action of the compressor 21, and then enters the outdoor heat exchanger 25 (acting as a condenser) to exchange heat with the ambient air, and the refrigerant is cooled to become low-temperature liquid, and then is cooled and decompressed by the electronic expansion valve 24 to become low-temperature and low-pressure liquid, and then absorbs heat through the indoor heat exchanger 23 to evaporate into gaseous refrigerant, and then returns to the compressor to circulate. At this time, the indoor heat exchanger can produce ice water, and the ice water can be used for summer ice-cooled beverages and other applicable occasions.

[0054] In order to improve the system stability of the solid oxide fuel cell heat pump unit and maximize the fuel cell power generation efficiency, the utility model also sets up the power distribution module 3, the electricity generated by the generator set is distributed through the power distribution module, including converting direct current into alternating current through the inverter 31, driving the heat pump unit 2 to work, or supplying power to other electrical loads, charging the energy storage battery pack 32, or merging into the power grid to supply power to the power grid.

[0055] Figure 1 In the embodiment shown, the energy storage battery pack 32 can be a lithium battery pack or a lead-acid battery pack. The energy storage battery pack is used as a backup power supply for the heat pump unit, and the electricity generated by the generator set charges the energy storage battery pack. At the moment of starting the heat pump unit, the battery pack and the alternating current can be mixed to supply power, so as to reduce the peak demand of the fuel cell power generation. When the power generation is insufficient, the energy storage battery pack supplies power to the heat pump unit, so as to maintain the stability of the system. When the generator set is stably operated, the excess power can be merged into the power grid, so as to relieve the pressure of the power grid and maximize the power generation efficiency of the generator set.

[0056] The control module 8 of the utility model as shown in the figure comprises: Figure 2

[0057] The power generation control module is used for monitoring and controlling the flow and temperature of the fuel gas and air, and monitoring and controlling the reaction temperature of the electric pile;

[0058] ​A power distribution control module is used to monitor and regulate the power consumption of each electrical load.

[0059] A heat pump control module is used to monitor the hot water temperature, pipe pressure, fan speed and refrigerant flow rate.

[0060] A hot flue gas recovery control module is used to detect the temperature and flow rate of hot flue gas and tail gas, and to detect and regulate the temperature of hot water.

[0061] The utility model discloses a more complete power distribution module, and the electricity generated by natural gas as fuel not only supplies the heat pump unit, energy storage battery pack and other electrical appliances, and the excess electricity can also be integrated into the power grid, thereby achieving the purpose of maximizing fuel cell power generation efficiency and relieving the pressure of the power grid.

[0062] It should be noted that for those skilled in the art, without departing from the concept of the utility model, a number of modifications and changes can be made, and these modifications and changes shall belong to the protection scope of the utility model.

Claims

1. A heat pump unit utilizing waste heat from power generation by a fuel cell, comprising a generator unit and a heat pump unit, characterized in that: It also includes a heat exchanger group and a hot water storage tank. The exhaust gas of the generator set is introduced into the heat exchanger group through a pipeline to exchange heat with water. The heated hot water is introduced from the heat exchanger into the hot water storage tank. The refrigerant in the indoor heat exchanger of the heat pump unit exchanges heat with water, and the heated water is connected to the hot water storage tank through a pipeline.

2. The heat pump unit according to claim 1, wherein: The heat exchanger group consists of a first heat exchanger and a second heat exchanger. The generator set includes a burner, a fuel gas heat exchanger and an air heat exchanger. The high-temperature flue gas of the burner is connected to the fuel gas heat exchanger and the air heat exchanger through pipes respectively. The exhaust gas discharged from the fuel gas heat exchanger is introduced into the first heat exchanger, and the exhaust gas discharged from the air heat exchanger is introduced into the second heat exchanger.

3. The heat pump unit according to claim 2, characterized in that: The burner is also connected to the air inlet pipe of the first heat exchanger through a first bypass and to the air inlet pipe of the second heat exchanger through a second bypass. Both the first bypass and the second bypass are provided with electric valves.

4. The heat pump unit according to claim 1, wherein: The heat pump unit includes a compressor, an indoor heat exchanger, a four-way reversing valve, an electronic expansion valve and an outdoor heat exchanger. The water outlet pipe of the indoor heat exchanger is connected to the hot water storage tank.

5. The heat pump unit according to claim 1, wherein: The exhaust gas discharged from the heat exchanger group is introduced into the outdoor heat exchanger for defrosting and heat exchange with the refrigerant.

6. The heat pump unit according to claim 2, characterized in that: The first heat exchanger, the second heat exchanger and the indoor heat exchanger are all shell-and-tube heat exchangers.

7. The heat pump unit according to claim 2, characterized in that: The fuel gas used for power generation is connected to the fuel gas heat exchanger and the burner through pipelines respectively, and the air is connected to the air heat exchanger and the burner through pipelines respectively. The preheated fuel gas discharged from the fuel gas heat exchanger enters the fuel reformer for reforming, and then undergoes electrochemical reaction in the reactor stack of the generator set together with the air preheated by the air heat exchanger to generate electricity, and the exhaust gas generated by the electrochemical reaction is introduced into the burner.

8. The heat pump unit according to claim 7, characterized in that: The reactor stack adopts a solid oxide fuel cell stack.

9. The heat pump unit according to claim 1, wherein: The generator set further includes a power distribution module for charging the energy storage battery pack, or supplying power to the heat pump unit or other loads through the inverter, and / or integrating the generated power into the power grid.

10. The heat pump unit according to claim 9, characterized in that: Also included is a control module, the control module comprising: Power generation control module, used to monitor and control the flow and temperature of fuel gas and air, and monitor and control the reaction temperature of the fuel cell stack; Power distribution control module, used to monitor and adjust the power consumption of each power load; Heat pump control module, used to monitor hot water temperature, pipeline pressure, fan speed and refrigerant flow; The hot flue gas recovery control module is used to detect the temperature and flow of hot flue gas and exhaust gas, and to detect and adjust the temperature of hot water.

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