Device for absorbing heat from low-temperature heat source and generating electric energy

Abstract

The invention relates to the technical field of energy conversion, in particular to a device for absorbing heat energy from the environment through a heat pump and converting the heat energy into electric energy, and belongs to the cross application technology of new energy and heat energy and electric energy conversion. According to the efficient device for converting the low-temperature heat energy into the electric energy, after heat is enriched through the heat pump, the expansion device, the hydraulic device and the capacitor structure are sequentially utilized, the heat energy is converted into the available electric energy, and therefore cyclic utilization of the energy is achieved, and the energy utilization efficiency is improved. And a cold source generated at the cold end of the heat pump is a by-product of the product.

Description

Technical Field

[0001] The present invention relates to the technical field of energy conversion, in particular to a device that absorbs heat energy from the environment through a heat pump and converts it into electrical energy, belonging to the cross - application technology of new energy and heat - energy - to - electrical - energy conversion. Background Art

[0002] Currently, heat pumps are widely used in scenarios such as refrigeration and heating, with characteristics such as high efficiency and energy conservation. However, their efficiency for direct power generation is relatively low. Traditional heat - energy power generation methods rely on high - temperature heat sources, and low - temperature heat sources are often wasted due to their low energy density. How to effectively utilize low - temperature heat sources to extract electrical energy from low - temperature environments is an important technical issue. Summary of the Invention

[0003] The purpose of the present invention is to provide a device for efficiently converting low - temperature heat energy into electrical energy. After enriching heat through a heat pump, it sequentially utilizes an expansion device, a hydraulic device, and a capacitive structure to convert heat energy into available electrical energy, thereby realizing the recycling of energy and improving energy utilization efficiency. Moreover, the cold source generated at the cold end of the heat pump is a by - product of this product.

[0004] [Technical Solution] The device of the present invention includes the following four parts: 1. Heat pump unit: It is used to absorb heat from the surrounding environment and enrich the heat to a high - temperature end, forming a high - low temperature heat source difference. The heat pump consumes a small amount of electrical energy and can obtain several times more heat than the input electrical energy. Its coefficient of performance COP is greater than 1, preferably 3 or above.

[0005] 2. Thermal expansion unit: It includes a rigid container and an expansion medium (such as kerosene), which expands after absorbing the heat conducted by the heat pump, pushing the piston to form mechanical energy. The piston is connected to a hydraulic system to achieve energy output. The expansion process involves two stages: heat - capacity temperature rise and volume expansion. Through the design of the container structure, the output pressure and displacement are controlled.

[0006] 3. Hydraulic amplification unit: It uses a hydraulic structure to convert a small amount of high - pressure liquid output by the expansion unit into a large - volume, low - pressure liquid motion, reducing the pressure while amplifying the stroke, facilitating the subsequent driving of the capacitor plates to move.

[0007] 4. Electrical energy conversion unit: It adopts a multi - layer variable - capacity capacitive structure. Assuming the initial distance between the plates is 1μm, after injecting liquid, the distance becomes 2μm, the capacitance capacity decreases, and under the condition of constant charge, the voltage rises, realizing the release of electrical energy.

[0008] The present invention also includes a liquid discharge and cooling circulation system to cool and recycle the expansion medium for repeated use, realizing a closed - loop cycle. Advantageous Effects

[0009] 1. Achieve effective extraction of electric energy from low-temperature heat sources and improve the utilization rate of thermal energy; 2. The structure is designed to be enclosed, with strong energy recyclability and sustainable operation; 3. When used in combination with traditional air conditioners, it can achieve cooling without additional energy consumption; 4. Modular design, multiple units can be connected in series to achieve continuous power supply. Description of the Drawings Figure 1 : Overall structure diagram of the 1-3 part system. Figure 2 : Schematic diagram of the multi-layer capacitor structure. Detailed Implementation Manner The present invention will be further described below in conjunction with specific data and embodiments: I. Using a heat pump to absorb heat from normal temperature and generate electricity 1. Assume that the input electric energy of the heat pump is 10 kJ and the coefficient of performance COP is 3, then the heat absorbed from the environment is 30 kJ.

[0012] 2. The thermal expansion unit uses a rigid container with a side length of 0.1 m and contains 1 L of kerosene. The specific heat capacity of kerosene is about 2100 J / (kg·°C). Assume that the density of kerosene is about 0.8 kg / L, then its mass is 0.8 kg.

[0013] Here, due to the law of conservation of energy, we make two assumptions. Assumption 1: During the expansion work process of the medium, part of the energy is used for its own temperature increase and part is for external work output. Assumption 2: During the expansion work process of the medium, the energy does not affect the external work output while increasing its own temperature, that is, while increasing the temperature, kinetic energy can be output externally. In actual application scenarios, the situation should be between the two.

[0014] ○ Assumption 1: 20 kJ is used for temperature increase, and the temperature rise ΔT = Q / (mc) = 20000 / (0.8×2100) ≈ 11.9 °C; the remaining 10 kJ generates expansion work; ○ Assumption 2: 30 kJ is all used for temperature increase and expansion, and the temperature rise ΔT ≈ 17.8 °C.

[0015] ○ The thermal expansion coefficient of kerosene is about 0.1% / °C, then the volume expansion is: § Assumption 1: 12 ml; § Assumption 2: 17.8 ml.

[0016] ○ The piston area is 0.01 m² (0.1 m×0.1 m), and the displacement is 1.2 mm or 1.78 mm.

[0017] ○ If the expansion outputs 10 kJ of mechanical energy, then the acting force F = W / S = 10 kJ / 0.0012 m ≈ Hypothesis 1: 833 kN, and the pressure is 833 MPa; Hypothesis 2: 5617 kN, and the pressure is 561.7 MPa (theoretical value).

[0018] 3. The hydraulic device amplifies the high-pressure small-volume liquid to 1000 ml, and reduces the output pressure to about 10 MPa, achieving low-pressure large-stroke drive with energy conservation.

[0019] 4. Capacitor unit: The initial distance between the capacitor plates of each layer is 1 μm, the capacitance is 0.001 F, the initial charging voltage is 100 V, and the electric charge is 0.1 C. After injecting the electrolyte, the initial distance between the plates changes from 1 μm to 2 μm, the capacitance decreases to 0.0005 F, and the electric charge remains unchanged Q = 0.1 C (when U = 100 V), and the new voltage U = Q / C = 200 V.

[0020] ○ The energy released by each layer of capacitor is ΔW = Q×ΔU = 0.1 C×100 V = 10 J; the total energy released by 1000 layers is 10 kJ.

[0021] ○ When the liquid is injected, it pushes the plate to rise 1 μm. The total stroke of 1000 layers is 1 mm, and the corresponding work done is W = F×S = 1 MN×0.001 m = 1 kJ; multiplied by 1000 layers, it is 10 kJ, which is consistent with the released electric energy.

[0022] 5. A liquid discharge port is provided between the capacitor layers. It is opened after the capacitor discharges. The plates are reset by the Coulomb force between the plates, the liquid is discharged, and the original distance is restored to complete the cycle.

[0023] II: Waste heat recovery application** Using the 80°C waste water from the power plant as the high-temperature heat source, omitting the heat pump module, and directly outputting electric energy through the expansion power generation module and the capacitor module.

Claims

1. A device that absorbs heat from a low-temperature heat source and generates electric energy It is characterized in that Comprising: • A heat pump unit for absorbing heat from the environment and outputting a high-temperature heat source; • A thermal expansion unit including a rigid container and an expansion medium, which generates mechanical energy after absorbing heat; • A hydraulic amplification unit for converting the mechanical energy of a high pressure and small stroke into a low pressure and large stroke output; • An electric energy conversion unit including a multi-layer variable-capacity capacitor structure, which realizes the change of the capacitor capacity by mechanical pushing and outputs electric energy.

2. Removing the heat pump unit, and using the thermal expansion unit, the hydraulic amplification unit, and the electric energy conversion unit to realize waste heat recovery power generation in factories such as power plants.

3. An energy-saving refrigeration device using the cold source of this patent as a refrigeration device.

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