Off-grid living cabin combined cooling heating and power system

Abstract

The utility model relates to a lithium bromide absorption refrigeration, solar heat collection and fuel cell waste heat utilization coupling energy supply system, in particular to an off-grid living cabin combined cooling heating and power supply system. The proton exchange membrane fuel cell, the medium-temperature solar heat collector and the single-effect lithium bromide absorption refrigeration unit are coupled to realize cold, heat and electricity combined supply. The system comprises a fuel cell cogeneration unit, a solar heat collector (5) and a lithium bromide absorption refrigeration unit.

Description

Technical Field

[0001] This patent relates to an off-grid living cabin combined cooling, heating and power system. Background Technology

[0002] In remote mountainous areas, rural villages, border outposts, and islands, where geographical constraints limit the cost of power grid installation or its coverage is insufficient, off-grid living pods can serve as a temporary or long-term accommodation solution. For example, they can provide shelter for personnel conducting geological exploration and ecological research in mountainous regions, workers in oil fields and mines, and those developing or stationed on uninhabited islands far from the mainland. They can provide the necessary heat and electricity for their living and working equipment (such as computers and communication devices). The independence of the living pods allows for greater flexibility in logistical support, such as material transportation, requiring only periodic replenishment of supplies.

[0003] Existing off-grid living quarters primarily use diesel generators, which can provide stable power for various electrical devices such as lighting, air conditioning, refrigerators, and televisions in the event of a mains power failure or lack of grid connection. However, the combustion of diesel fuel by these generators produces exhaust emissions, mainly including nitrogen oxides, particulate matter, and sulfur dioxide, which negatively impact air quality inside and around the living quarters. Small diesel engines under 10kW typically produce noise levels between 80 and 95 decibels. According to my country's "Environmental Noise Quality Standard" (GB 3096-2008), areas primarily used for industrial production and warehousing logistics, requiring measures to prevent severe environmental impacts from industrial noise, are classified as Class 3 acoustic environment functional zones, with a daytime equivalent sound level limit of 65 decibels and a nighttime limit of 55 decibels. Both of these factors significantly reduce the quality of life for users. Furthermore, the currently prevalent air conditioning systems are traditional compressor-type electric air conditioners, which primarily use CFC refrigerants, contributing to ozone layer depletion. Summary of the Invention

[0004] To address the above issues, this patent's fuel cell cogeneration waste heat utilization system and its control method can achieve waste heat redistribution and stable heat supply through dynamic control, solving the problems of large fluctuations in user-end heating temperature and stable fuel cell stack entry temperature. At the same time, it improves waste heat utilization efficiency, achieves a stable supply of hot water and heating temperatures at the user end, and ensures the stability of the fuel cell stack entry temperature.

[0005] The specific technical solution is as follows:

[0006] An off-grid living cabin combined cooling, heating, and power (CCHP) system is characterized by comprising: a fuel cell CCHP unit, a solar collector unit, and a lithium bromide absorption refrigeration unit, wherein...

[0007] The fuel cell cogeneration unit includes: fuel cell (1), PTC heater (2), cooling fan (3), first valve (11), second valve (12), third valve (13), and fourth valve (14); the solar collector unit includes: hot water storage tank (4), solar collector (5), temperature sensor (23), fifth valve (15), sixth valve (16), seventh valve (17), and eighth valve (18); the lithium bromide absorption refrigeration unit includes: cold water tank (6), generator (7), condenser (8), throttle valve (24), evaporator (9), absorber (10), ninth valve (19), and tenth valve (20). Hot water in the hot water storage tank (4) is fed into the generator (7), and the valves are opened and closed by the feedback signal of the temperature sensor (23).

[0008] Furthermore, the waste heat from the fuel cell (1) is supplied to the hot water storage tank (4); the solar collector (5) heats the water in the hot water storage tank (4), and the hot water flows to the generator (7) to heat the lithium bromide solution in the generator (7); water vapor enters the condenser (8), is cooled and condensed into liquid water by the cooling water in the cold water tank (6), and the liquid water enters the evaporator (9) through the throttle valve (24), the solution concentration in the generator (7) increases, and the solution enters the absorber (10); low-temperature water vapor enters the absorber (10), and after the solution concentration gradually decreases, it returns to the generator (7).

[0009] Beneficial effects

[0010] This patent couples a solar collector, a lithium bromide absorption refrigeration system, and a fuel cell combined heat and power system to provide combined cooling, heating, and power for an off-grid living cabin. Solar energy is the primary source of heat, with waste heat from the fuel cell serving as a supplement. Lithium bromide absorption refrigeration converts the solar energy into cooling, and the fuel cell provides the electrical power.

[0011] Solar energy is intermittent, fuel cells need to balance power generation and waste heat supply, and user-side cooling / heating demands fluctuate with environmental changes. Existing technologies cannot achieve dynamic coordination among these three factors. This patent addresses this by using dynamic valve control (such as temperature sensor-triggered valve opening and closing) to adjust energy flow in real time, thereby controlling the switching between heating and cooling modes. This enables functions such as energy priority switching, temperature protection, and load matching, significantly improving system robustness.

[0012] (1) Enhanced system stability and reliability

[0013] This coupled system offers multiple energy input options, saving power consumption in the fuel cell system while its heat can compensate for the fluctuations and instabilities of solar energy. When solar energy is abundant, the solar collector can provide the primary energy source, meeting some of the cooling and heating needs. In situations where solar energy is insufficient, such as on cloudy days or at night, the fuel cell combined heat and power (CHP) system can function, providing both electricity and heat. This complementary energy supply method ensures stable system operation and reduces system failures or performance degradation caused by insufficient supply of a single energy source.

[0014] (2) Environmental friendliness

[0015] Existing diesel generators produce pollutants such as nitrogen oxides, particulate matter, and sulfur dioxide when burning diesel fuel.

[0016] Solar energy is a clean energy source, producing almost no greenhouse gas emissions during its collection and utilization. Solar collectors operate without combustion, unlike traditional fossil fuel boilers which generate pollutants such as carbon dioxide and sulfur dioxide. Lithium bromide absorption chillers are driven by thermal energy, and the lithium bromide solution they use has a relatively low environmental impact. Compared to traditional Freon refrigeration systems, they avoid the use of ozone-depleting refrigerants like Freon, reducing negative impacts on the atmospheric environment. Proton exchange membrane fuel cells primarily produce water as a reaction byproduct during operation, without generating pollutants such as nitrogen oxides, which is of great significance for improving air quality and addressing climate change.

[0017] (3) Energy efficiency

[0018] Lithium bromide absorption refrigeration utilizes the waste heat from solar energy and fuel cell systems to replace traditional, high-power compressor-type air conditioners, resulting in significant energy savings when used in combined cooling, heating, and power systems.

[0019] (4) Quiet operation

[0020] The overall operating noise is 55-75 decibels, which is far lower than the 80-95 decibels of existing diesel engines. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the system in this patent.

[0022] Figure 2 This is the system control flowchart of this patent. Detailed Implementation

[0023] The technical solutions of this patent embodiment will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this patent, and not all of them. Based on the embodiments of this patent, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this patent.

[0024] In existing designs, proton exchange membrane fuel cell combined heat and power systems consist of a fuel cell stack, a hydrogen supply system, an air supply system, a cooling system, an electrical control system, and a waste heat recovery system. Their drawback is that the temperature at which waste heat can be recovered from proton exchange membrane fuel cells is relatively low (between 60 and 80°C). Typically, waste heat can only be recovered as hot water for heating and domestic hot water applications. This limits the efficiency and value of waste heat utilization, leading to situations where high cooling loads in summer result in insufficient electrical power while heating is not fully utilized, or insufficient waste heat in winter prevents adequate heating.

[0025] Lithium bromide absorption refrigeration mainly consists of a generator, condenser, evaporator, and absorber. The single-effect lithium bromide absorption chiller is the basic type of absorption chiller, typically using saturated steam (or hot water at 70-120°C) at 0.03~0.15 MPa (gauge pressure), but its thermal efficiency is relatively low, with a COP of approximately 0.65~0.7.

[0026] Solar collectors are classified into low-temperature solar collectors and medium-temperature solar collectors based on the range of hot water temperatures. Although solar collectors can utilize solar energy resources free of charge, the low solar irradiance under natural conditions limits the ratio of the collector's light-receiving area to the air-conditioned building area.

[0027] To address the shortcomings of existing technologies, this patent proposes a coupled system of solar absorption cooling and heating air conditioning and fuel cell cogeneration. The fuel cell utilizes a proton exchange membrane stack, the lithium bromide absorption cooling is a single-effect hot water type, and the solar collector is a medium-temperature heat pipe vacuum collector.

[0028] like Figure 1 As shown, a coupled system of solar absorption cooling and heating air conditioning and fuel cell cogeneration is disclosed, wherein 1 is a fuel cell cogeneration system, 2 is a PTC heater, 3 is a cooling fan, 4 is a thermal expansion tank, 5 is a solar collector, 6 is a cold water tank, 7 is a generator, 8 is a condenser, 9 is an evaporator, 10 is an absorber, 11 is a first valve, 12 is a second valve, 13 is a third valve, 14 is a fourth valve, 15 is a fifth valve, 16 is a sixth valve, 17 is a seventh valve, 18 is an eighth valve, 19 is a ninth valve, 20 is a tenth valve, 21 is a heat user, 22 is a cooling user, 23 is a temperature sensor, and 24 is a throttling valve.

[0029] Among them, the waste heat of fuel cell 1 is supplied to hot water storage tank 4;

[0030] The solar collector 5 heats the water in the hot water storage tank 4, and the hot water is sent to the generator 7 to heat the lithium bromide solution in the generator 7.

[0031] Water vapor enters the condenser 8 and is cooled and condensed into liquid water by the cooling water in the cold water tank 6; the liquid water enters the evaporator 9 through the throttle valve 24;

[0032] The solution concentration in generator 7 increases, and the solution enters absorber 10; low-temperature water vapor enters absorber 10, and the solution concentration gradually decreases before returning to generator 7.

[0033] Hot water from the hot water storage tank 4 flows into the generator 7, and the valve opening and closing is controlled by the feedback signal from the temperature sensor 23. This scheme couples the solar collector, lithium bromide absorption refrigeration, and fuel cell combined heat and power system to provide combined cooling, heating, and power for the off-grid living cabin. Solar energy is the primary source of heat supply, with waste heat from the fuel cell as an auxiliary source. Lithium bromide absorption refrigeration converts the solar heat into cooling, and the fuel cell provides the electricity.

[0034] More specifically, such as Figure 2 The system has five operating modes:

[0035] (1) When there is no heating or cooling demand from heat user 21 and cold user 22, the first valve 11, the second valve 12, the fifth valve 15, the sixth valve 16, the seventh valve 17, the eighth valve 18, the ninth valve 19, and the tenth valve 20 are closed during fuel cell operation, and the third valve 13 and the fourth valve 14 are opened. The cooling water outlet pipe of fuel cell system 1 is connected to the hot water storage tank 4 for heat exchange, and the waste heat of fuel cell system 1 is stored in the hot water storage tank 4.

[0036] (2) When there is sunshine, and the heat user 21 has a heating demand, the first valve 11 and the second valve 12 of the fuel cell system 1 are closed, and the third valve 13 and the fourth valve 14 are opened, supplying the waste heat of the fuel cell system 1 to the hot water storage tank 4. At the same time, the fifth valve 15 and the sixth valve 16 are opened, and the seventh valve 17, the eighth valve 18, the ninth valve 19, and the tenth valve 20 are closed. The water in the hot water storage tank 4 is further heated by the solar collector 5, and the hot water is supplied to the heat user 21 for heating. In summer at noon, in areas with strong sunshine and weather conditions, when the temperature sensor 23 detects that the temperature of the hot water in the hot water storage tank 4 exceeds 90°C, the third valve 13 and the fourth valve 14 are closed, and the first valve 11 and the second valve 12 are opened, so that the waste heat of the fuel cell system 1 is discharged into the environment through the cooling fan 3 to avoid the stack operating temperature from being too high. When the temperature detected by the temperature sensor 23 is lower than 80°C, the third valve 13 and the fourth valve 14 are reopened, and the first valve 11 and the second valve 12 are closed.

[0037] (3) When there is sunshine, and the user 22 has a cooling demand, the first valve 11 and the second valve 12 of the fuel cell system 1 are closed, and the third valve 13 and the fourth valve 14 are open, supplying the waste heat of the fuel cell system 1 to the hot water storage tank 4. The fifth valve 15 and the sixth valve 16 are closed, and the seventh valve 17, the eighth valve 18, the ninth valve 19, and the tenth valve 20 are open. The water in the hot water storage tank 4 is further heated by the solar collector 5. The hot water is sent to the generator 7. After the lithium bromide solution in the generator 7 is heated by the hot water, the water in the solution vaporizes. The water vapor enters the condenser 8. As the water continues to vaporize, the concentration of the solution in the generator 7 continues to increase and enters the absorber 10. The water vapor entering the condenser 8 is cooled by the cooling water in the cold water tank 6 and condenses into liquid water. It enters the evaporator 9 through the throttle valve 24, expands rapidly and vaporizes. During the vaporization process, it absorbs a large amount of heat from the refrigerant water in the evaporator 9. The cooled refrigerant water is sent to the user 22 for cooling. Low-temperature water vapor enters the absorber 10 and is absorbed by the concentrated lithium bromide solution inside the absorber 10. The solution concentration gradually decreases and is sent back to the generator 7.

[0038] (4) In the absence of sunlight, when heat user 21 has a heating demand, the first valve 11 and the second valve 12 of the fuel cell system 1 are closed, and the third valve 13 and the fourth valve 14 are open, supplying the waste heat of the fuel cell system 1 to the hot water storage tank 4. The fifth valve 15 and the sixth valve 16 are open, and the seventh valve 17, the eighth valve 18, the ninth valve 19, and the tenth valve 20 are closed. The hot water in the storage tank 4 is directly supplied to the heat user. When the temperature sensor 23 detects that the temperature of the storage tank 4 is lower than 60°C, the PTC heater 2 in the fuel cell system 1 is turned on to increase the temperature of the hot water supplied to the heat user 21.

[0039] (5) In the absence of sunlight, when the user 22 has a cooling demand, the first valve 11 and the second valve 12 of the fuel cell system 1 are closed, and the third valve 13 and the fourth valve 14 are open, supplying the waste heat of the fuel cell system 1 to the hot water storage tank 4. The fifth valve 15 and the sixth valve 16 are closed, and the seventh valve 17, the eighth valve 18, the ninth valve 19, and the tenth valve 20 are open. The hot water in the hot water storage tank 4 is directly supplied to the generator 7 for cooling according to the steps in situation (3). When the temperature sensor 23 detects that the temperature of the water storage tank 4 is lower than 60°C, the PTC heater 2 in the fuel cell system 1 is turned on to increase the temperature of the hot water supplied to the generator 7 and ensure the cooling efficiency.

[0040] The advantages of this patent are:

[0041] This patent couples a solar collector, a lithium bromide absorption refrigeration system, and a fuel cell combined heat and power system to provide combined cooling, heating, and power for an off-grid living cabin. Solar energy is the primary source of heat, with waste heat from the fuel cell serving as a supplement. Lithium bromide absorption refrigeration converts the solar energy into cooling, and the fuel cell provides the electrical power.

[0042] (1) Enhanced system stability and reliability

[0043] This coupled system offers multiple energy input options, saving power consumption in the fuel cell system while its heat can compensate for the fluctuations and instabilities of solar energy. When solar energy is abundant, the solar collector can provide the primary energy source, meeting some of the cooling and heating needs. In situations where solar energy is insufficient, such as on cloudy days or at night, the fuel cell combined heat and power (CHP) system can function, providing both electricity and heat. This complementary energy supply method ensures stable system operation and reduces system failures or performance degradation caused by insufficient supply of a single energy source.

[0044] (2) Environmental friendliness

[0045] Existing diesel generators produce pollutants such as nitrogen oxides, particulate matter, and sulfur dioxide when burning diesel fuel.

[0046] Solar energy is a clean energy source, producing almost no greenhouse gas emissions during its collection and utilization. Solar collectors operate without combustion, unlike traditional fossil fuel boilers which generate pollutants such as carbon dioxide and sulfur dioxide. Lithium bromide absorption chillers are driven by thermal energy, and the lithium bromide solution they use has a relatively low environmental impact. Compared to traditional Freon refrigeration systems, they avoid the use of ozone-depleting refrigerants like Freon, reducing negative impacts on the atmospheric environment. Proton exchange membrane fuel cells primarily produce water as a reaction byproduct during operation, without generating pollutants such as nitrogen oxides, which is of great significance for improving air quality and addressing climate change.

[0047] (3) Energy efficiency

[0048] Lithium bromide absorption refrigeration utilizes the waste heat from solar energy and fuel cell systems to replace traditional, high-power compressor-type air conditioners, resulting in significant energy savings when used in combined cooling, heating, and power systems.

[0049] (4) Quiet operation

[0050] The overall operating noise is 55-75 decibels, which is far lower than the 80-95 decibels of existing diesel engines.

[0051] It should be noted that the above embodiments are only used to illustrate the technical solutions of this patent, and not to limit them; although this patent has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this patent.

Claims

1. An off-grid living cabin combined cooling, heating, and power (CCHP) system, characterized in that, include: The fuel cell combined heat and power unit, the solar collector unit, and the lithium bromide absorption refrigeration unit, among which... The fuel cell cogeneration unit includes: fuel cell (1), PTC heater (2), cooling fan (3), first valve (11), second valve (12), third valve (13), and fourth valve (14); the solar collector unit includes: hot water storage tank (4), solar collector (5), temperature sensor (23), fifth valve (15), sixth valve (16), seventh valve (17), and eighth valve (18); the lithium bromide absorption refrigeration unit includes: cold water tank (6), generator (7), condenser (8), throttle valve (24), evaporator (9), absorber (10), ninth valve (19), and tenth valve (20). Hot water in the hot water storage tank (4) is fed into the generator (7), and the valves are opened and closed by the feedback signal of the temperature sensor (23).

2. The off-grid living cabin combined cooling, heating, and power system according to claim 1, characterized in that, The waste heat from the fuel cell (1) is supplied to the hot water storage tank (4); the solar collector (5) heats the water in the hot water storage tank (4), and the hot water is sent to the generator (7) to heat the lithium bromide solution in the generator (7); water vapor enters the condenser (8), is cooled and condensed into liquid water by the cooling water in the cold water tank (6), and the liquid water enters the evaporator (9) through the throttle valve (24), the solution concentration in the generator (7) increases, and the solution enters the absorber (10); low-temperature water vapor enters the absorber (10), and after the solution concentration gradually decreases, it returns to the generator (7).

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