A self-driven thermal energy upgrading device and circulation method for an asymmetric piston cylinder
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- 袁伟
- Filing Date
- 2026-05-08
- Publication Date
- 2026-06-30
AI Technical Summary
Existing thermal energy upgrade devices require external power, resulting in high operating costs, and there is a lack of self-driven solutions that fully utilize thermal energy.
It adopts an asymmetric piston cylinder structure, and through the closed circulation of the working fluid and the isolation design of the steam circuit, it utilizes the piston area difference to achieve self-driven compression and expansion, realizing the upgrade of medium and low temperature thermal energy, including closed heat pump scheme and steam pressurization scheme.
It achieves the efficient conversion of medium and low temperature thermal energy into high-grade high temperature thermal energy, and the efficient recovery and utilization of waste heat resources, without the need for external power input.
Smart Images
Figure CN122305673A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the fields of thermal energy engineering, waste heat recovery and heat pump technology, and specifically to a thermal energy upgrading device and method that utilizes an asymmetric piston cylinder structure to achieve self-driving without a motor or compressor. Background Technology
[0002] Industrial production generates a large amount of medium- and low-temperature waste heat resources. Traditional heat pump technology requires electricity to drive the compressor, resulting in high operating costs. Current technology lacks a self-driven thermal energy upgrade device that utilizes thermal energy entirely and requires no external power input. To address the issue that existing thermal energy upgrading devices require external power, this invention provides two self-driven technical solutions relying on waste heat. These solutions respectively achieve closed-loop working fluid circulation thermal energy upgrading and direct compression and pressurization of low-pressure waste steam. By utilizing the asymmetric piston cylinder area difference, self-driven compression and expansion are achieved, directly converting medium- and low-temperature thermal energy into high-grade and high-temperature thermal energy, thus realizing efficient recovery and utilization of waste heat. Summary of the Invention
[0003] This invention provides two independent technical solutions that share the core structure of the asymmetric work unit, but the working fluid circuit and the steam circuit are completely isolated and do not mix: 1) Closed-loop heat pump solution: adopts a closed-loop working fluid circulation to upgrade medium and low temperature waste heat into high temperature heat energy / steam; 2) Steam pressurization scheme: The working fluid is introduced into the large cylinder to provide power, and the small cylinder independently compresses the external low-pressure waste steam to realize the high value of waste steam. The asymmetric work unit can adopt multiple parallel structures to increase the processing flow rate, or it can adopt a multi-stage series (cascade) structure to achieve step-by-step temperature and pressure increase, so as to meet the industrial heat demand of higher temperature and higher pressure. Device Composition An evaporator is used to heat a working fluid using a medium- or low-temperature heat source. An asymmetric working unit includes a first cylinder and a second cylinder, wherein the effective piston area of the first cylinder is larger than that of the second cylinder, and the pistons of the two cylinders are rigidly connected by the same piston rod. The high-pressure condenser has its inlet connected to the exhaust port of the second cylinder and is used to condense high-temperature and high-pressure working fluids or output pressurized steam. The low-pressure condenser has its inlet connected to the exhaust port of the first cylinder and is used to condense the low-pressure working fluid. Working fluid pump and throttling element. Connection Closed-loop heat pump solution: The evaporator outlet is simultaneously connected to the air inlets of the first and second cylinders; the high-pressure condenser outlet is connected to the evaporator inlet via a throttling element; the low-pressure condenser outlet is connected to the evaporator inlet via a working fluid pump. Steam pressurization scheme: The evaporator outlet is only connected to the air inlet of the first cylinder; the second cylinder is independently connected to external low-pressure waste steam and is not connected to the working fluid circuit. Multiple sets of asymmetric working units can be connected in parallel to increase the working fluid circulation flow rate; or they can be connected in series (cascaded) in multiple stages, with the high-temperature heat output from the front high-pressure condenser serving as the heat source for the subsequent evaporator, achieving step-by-step temperature and pressure increases. Working principle Closed-loop heat pump mode: The working fluid absorbs waste heat, evaporates, and becomes superheated in the evaporator; The superheated working fluid enters the first and second cylinders simultaneously; The piston is driven to move by the thrust difference generated by the piston area difference and the working fluid pressure, which adiabatically compresses the working fluid in the second cylinder, causing its temperature and pressure to rise. The high-temperature, high-pressure working fluid discharged from the second cylinder enters the high-pressure condenser to release heat and condense. The low-pressure working fluid discharged from the first cylinder enters the low-pressure condenser for condensation. The low-pressure condensate is pumped back to the evaporator via a working fluid pump, while the high-pressure condensate is pumped back to the evaporator after being throttled, cooled, and depressurized by a throttling element, thus completing a closed-loop cycle. Steam pressurization mode: The working fluid circulates in a closed loop only between the evaporator, the first cylinder, and the low-pressure condenser. The working fluid is heated and generates pressure, which drives the piston to move and provides compression power to the second cylinder. The second cylinder draws in low-pressure waste steam from the outside and performs adiabatic compression. The compressed high-temperature and high-pressure steam is directly output, realizing the high-value utilization of waste steam; The working fluid and the steam to be compressed are completely isolated and do not mix.
[0004] When a parallel structure is adopted, multiple sets of asymmetric work units operate synchronously, significantly improving the system's heat flow; when a multi-stage series (cascade) structure is adopted, the high-temperature heat energy output from the front stage drives the subsequent stage system, achieving a step-by-step increase in temperature and pressure. Attached Figure Description Figure 1 is a schematic diagram of the process flow of the present invention; The image is labeled as follows: E101: Evaporator (with superheater section) C101: Asymmetric power unit (large cylinder + small cylinder) E102: Low-pressure condenser E103: High-pressure condenser P101: Working fluid transfer pump Hot water inlet: Waste hot water inlet Cool water inlet: Cooling water inlet Steam outlet: High-temperature steam outlet Cooled water outlet Detailed Implementation
[0005] Example 1 (Closed-loop heat pump solution) The piston area of the first cylinder (large cylinder) is 400cm², and the piston area of the second cylinder (small cylinder) is 100cm², with an area ratio of 4:1; the working fluid is HFC-365mfc. Evaporator: 90℃ waste hot water heating, working fluid evaporation temperature 80℃, pressure 0.22MPa; The small cylinder compresses the air to a pressure of approximately 0.80 MPa and a temperature of approximately 135°C. The high-pressure condenser has a condensation temperature of approximately 130°C and produces saturated steam at 125°C. The low-pressure condenser maintains negative pressure operation to achieve automatic piston reset. The system upgrades the thermal energy of 90℃ low-temperature waste heat to 125℃ industrial steam, driven purely by heat, without motors or compressors. Example 2 (Steam pressurization scheme) The evaporator is connected to the first cylinder only, while the second cylinder is directly connected to external low-pressure waste steam, completely isolating the working fluid from the steam. Steam to be pressurized: 104℃, 0.115MPa low-pressure waste steam; Cylinder area ratio 4:1; The small cylinder compresses the steam to 0.46 MPa, forming superheated steam at about 170°C, which can be directly reused for industrial heating. The system is powered by a 90°C waste hot water-driven atmospheric cylinder, and the entire system is self-driving. The working fluid used is HFC-365mfc, n-pentane, etc. Example 3 (Parallel Capacity Expansion) By employing two or more sets of asymmetric working units operating in parallel, the evaporator simultaneously supplies gas to multiple working units, doubling the system's working fluid circulation flow rate under the same heat source conditions, significantly increasing the total steam production and heating capacity, and making it suitable for large-flow industrial waste heat scenarios. Example 4 (Series Cascade Heating) The system adopts a multi-stage series (cascade) structure: the first stage outputs 125℃ steam as the heat source for the second stage evaporator; the second stage continues to increase the temperature and pressure, eventually producing high-pressure steam above 160℃, and so on, to realize the step-by-step upgrade of medium and low temperature waste heat to ultra-high grade heat energy. Those skilled in the art will understand that the present invention can select different working fluids according to the heat source and condensation conditions, and achieve different pressurization and heating effects by adjusting the cylinder area ratio. The embodiments in this specification are merely illustrative and not exhaustive. Any technical solution employing an asymmetric piston cylinder self-driven structure to achieve thermal energy upgrading or steam pressurization falls within the protection scope of this invention.
Claims
1. An asymmetric piston cylinder self-driven thermal energy upgrading device, characterized in that, include: An evaporator is used to heat a working fluid using a medium- or low-temperature heat source. An asymmetric working unit includes a first cylinder and a second cylinder, wherein the effective piston area of the first cylinder is larger than that of the second cylinder, and the pistons of the two cylinders are rigidly connected by the same piston rod. The high-pressure condenser has its inlet connected to the exhaust port of the second cylinder, and is used to condense the high-temperature and high-pressure working fluid and output high-temperature heat energy. A low-pressure condenser, the inlet of which is connected to the exhaust port of the first cylinder, is used to condense a low-pressure working fluid; The outlet of the evaporator is connected to the air inlets of both the first and second cylinders; the outlet of the high-pressure condenser is connected to the working fluid inlet of the evaporator via a throttling element; and the outlet of the low-pressure condenser is connected to the working fluid inlet of the evaporator via a working fluid pump.
2. The apparatus according to claim 1, characterized in that, The effective piston area of the first cylinder is larger than that of the second cylinder. A preferred ratio is 2:1 to 6:
1.
3. The apparatus according to claim 1, characterized in that, The exhaust port of the first cylinder is equipped with an exhaust valve, which is configured to open and close when the piston moves to a predetermined position.
4. The apparatus according to claim 1, characterized in that, The low-pressure condenser is configured to operate at a negative or slightly positive pressure lower than the evaporator pressure.
5. The apparatus according to claim 1, characterized in that, The working fluid meets the following conditions: the condensing pressure of the low-pressure condenser is lower than the ratio of the suction pressure of the small cylinder to the cylinder area, which is more conducive to forming negative pressure.
6. The apparatus according to claim 1, characterized in that, The asymmetric work unit is provided in multiple sets and is connected in parallel to increase the circulation flow rate.
7. The apparatus according to claim 1, characterized in that, The device is configured with multiple stages and adopts a series (cascade) structure. The high-pressure condenser in the front stage provides a heat source for the evaporator in the back stage, realizing step-by-step temperature and pressure increase.
8. An asymmetric piston cylinder self-driven steam pressurization device, characterized in that, include: An evaporator is used to heat a working fluid using a medium- or low-temperature heat source. An asymmetric working unit includes a first cylinder and a second cylinder, wherein the effective piston area of the first cylinder is larger than that of the second cylinder, and the pistons of the two cylinders are rigidly connected by the same piston rod. An external steam source is connected to the air inlet of the second cylinder to supply low-pressure waste steam to be compressed. The high-pressure output end is connected to the exhaust port of the second cylinder and is used to output pressurized steam. A low-pressure condenser, the inlet of which is connected to the exhaust port of the first cylinder; The outlet of the evaporator is connected only to the air inlet of the first cylinder; the outlet of the low-pressure condenser is connected to the working fluid inlet of the evaporator via a working fluid pump.
9. A method for self-driven thermal energy upgrading cycle of an asymmetric piston cylinder, characterized in that, Based on the apparatus according to any one of claims 1-7, the method includes the following steps: S1. The working fluid absorbs waste heat, evaporates, and becomes superheated within the evaporator; S2. The superheated working fluid enters the first cylinder and the second cylinder simultaneously; S3. The piston is driven to move by the thrust difference generated by the piston area difference and the working fluid pressure, so as to perform adiabatic compression on the working fluid in the second cylinder, thereby increasing its temperature and pressure. S4. The high-temperature and high-pressure working fluid discharged from the second cylinder enters the high-pressure condenser to release heat and condense; S5. The low-pressure working fluid discharged from the first cylinder enters the low-pressure condenser for condensation; S6. The low-pressure condensate is pumped back to the evaporator via the working fluid pump, and the high-pressure condensate is pumped back to the evaporator after being throttled and depressurized by the throttling element, thus completing the cycle.