Alkali liquor waste heat flexible recovery system
By designing a flexible heat recovery system for alkali solution waste heat, the problem of unutilized thermal energy in alkali water hydrogen production was solved, achieving efficient energy utilization and improving the system's economic efficiency.
Patent Information
- Application Number
- CN202520209638.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-11
- Publication Date
- 2025-11-21
- Estimated Expiration
- 2035-02-11
AI Technical Summary
In existing alkaline water hydrogen production technology, thermal energy is not effectively utilized, resulting in energy waste and low energy conversion efficiency.
A flexible alkali waste heat recovery system was designed, including an electrolytic cell, a gas-liquid separation system, a circulating alkali pump, a refrigeration system, a heat storage system, and a heating system. The system components are flexibly adjusted to achieve efficient utilization of waste heat and adapt to seasonal and light changes.
This improved the energy efficiency of the hydrogen production process, reduced dependence on external energy sources, lowered overall energy costs, and achieved efficient utilization of alkaline thermal energy and system economy.
Smart Images
Figure CN223580270U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to alkali water hydrogen production technical field, concretely relates to a flexible recovery system of alkali liquor waste heat. BACKGROUND
[0002] Alkali water hydrogen production technology is formed under the background of global energy transformation and climate change response. With the increasing attention to reducing greenhouse gas emissions and achieving sustainable development, hydrogen energy as a clean energy has received widespread attention. Alkali water hydrogen production technology has become one of the most mature water electrolysis hydrogen production technologies due to its simple structure, low cost and mature technology.
[0003] Although alkali water hydrogen production technology (AWE) is widely used due to its maturity and low equipment cost, it still faces some challenges, including relatively low energy conversion efficiency and high energy consumption caused by it. In the traditional alkali water electrolysis hydrogen production process, a large amount of heat energy cannot be effectively utilized, resulting in energy waste. SUMMARY
[0004] The utility model discloses a flexible recovery system of alkali liquor waste heat, which realizes efficient utilization of alkali liquor heat energy.
[0005] To achieve the above-mentioned purpose, the utility model provides a flexible recovery system of alkali liquor waste heat, which comprises an electrolytic cell, a gas-liquid separation system, a circulating alkali liquor pump, a refrigeration system, a heat storage system and a heating system. After the alkali liquor and gas mixture produced by the electrolytic cell are separated by the hydrogen separator and oxygen separator of the gas-liquid separation system, the alkali liquor is adjusted in flow by the flow meter and the regulating valve through the alkali liquor circulating pump, and is delivered to the refrigeration system, the heat storage system and the heating system respectively.
[0006] Further, the refrigeration system comprises a refrigerated water tank, a refrigerated water circulating pump and a lithium bromide unit. The alkali liquor outlet of the gas-liquid separation system is connected to the tube inlet of the lithium bromide unit through the flow meter and the regulating valve by the alkali liquor circulating pump. The refrigerated water outlet of the refrigerated water tank is connected to the shell inlet of the lithium bromide unit through the refrigerated water circulating pump. The shell outlet of the lithium bromide unit is connected to the refrigerated water inlet of the gas-liquid separation system. The refrigerated water outlet of the gas-liquid separation system is connected to the refrigerated water inlet of the refrigerated water tank.
[0007] Further, the heat storage system comprises a cold water tank, a heat storage water tank, a heat storage water pump and an electrolytic tank heat preservation heat exchanger; the alkali liquor outlet of the gas-liquid separation system is connected with the pipe passage inlet of the electrolytic tank heat preservation heat exchanger through a flow meter and a regulating valve through an alkali liquor circulating pump, the outlet of the cold water tank is connected with the first shell passage inlet of the electrolytic tank heat preservation heat exchanger through a heat storage water pump, the first shell passage outlet of the electrolytic tank heat preservation heat exchanger is connected with the inlet of the heat storage water tank, the outlet of the heat storage water tank is connected with the second shell passage inlet of the electrolytic tank heat preservation heat exchanger through a heat storage water pump, and the second shell passage outlet of the electrolytic tank heat preservation heat exchanger is connected with the inlet of the cold water tank; meanwhile, the other way of the alkali liquor circulating pump is connected with the heat storage water inlet of the plant heating pipe network through a valve, and the heat storage backwater outlet of the plant heating pipe network is connected with the inlet of the cold water tank.
[0008] Further, the heating system comprises a hot water tank, a hot water pump and a heating heat exchanger, the alkali liquor outlet of the gas-liquid separation system is connected with the pipe passage inlet of the heating heat exchanger through a flow meter and a regulating valve through an alkali liquor circulating pump, the hot water outlet of the hot water tank is connected with the shell passage inlet of the heating heat exchanger through a hot water pump, the shell passage outlet of the heating heat exchanger is connected with the inlet of the plant heating pipe network, and the outlet of the plant heating pipe network is connected with the hot water inlet of the hot water tank.
[0009] Further, the shell passage outlet of the heating heat exchanger is directly connected with the hot water inlet of the hot water tank through a valve.
[0010] Further, the pipe passage outlet of the lithium bromide unit is returned to the electrolytic tank through a switch valve or is transported to the electrolytic tank after being air-cooled through an air cooling system through a switch valve.
[0011] Further, the pipe passage outlet of the electrolytic tank heat preservation heat exchanger is returned to the electrolytic tank through a switch valve or is transported to the electrolytic tank after being air-cooled through an air cooling system through a switch valve.
[0012] Further, the heating heat exchanger is returned to the electrolytic tank through a switch valve or is transported to the electrolytic tank after being air-cooled through an air cooling system through a switch valve.
[0013] Compared with the prior art, the alkali liquor waste heat flexible recycling system considers seasonal changes and different daily light intensities, and can be flexibly adjusted. In summer, when the plant does not need heating and the electrolytic tank does not need heat standby, the waste heat recycling system only runs the refrigeration system, and the air cooling system is responsible for taking away the excess heat; in winter, in order to meet the needs of plant heating and electrolytic tank heat standby, the refrigeration system, the heating system and the heat storage system will be operated at the same time, ensuring efficient use of energy; the system not only improves the energy efficiency of the hydrogen production process, but also reduces the dependence on external energy, effectively reduces the overall energy cost, realizes efficient use of alkali liquor heat energy, and improves the overall performance and economy of the system. BRIEF DESCRIPTION OF DRAWINGS
[0014] Figure 1The alkali liquor waste heat flexible recycling system process chart of the utility model. DETAILED DESCRIPTION
[0015] The utility model will be further explained in connection with the drawings and specific embodiments.
[0016] As Figure 1 The alkali liquor waste heat flexible recycling system, including electrolytic cell R101, gas-liquid separation system K201, circulating alkali liquor pump P101, refrigeration system K301, heat storage system K401, heating system K501 and air cooling system K601. The inlet alkali liquor temperature of electrolytic cell R101 is maintained at about 70 DEG C, and the alkali liquor temperature of electrolytic cell R101 outlet is controlled to not more than 100 DEG C. The alkali liquor and gas mixture produced by electrolytic cell R101 is separated by hydrogen separator and oxygen separator of gas-liquid separation system K201, and the temperature of alkali liquor is about 95 DEG C. The high-temperature alkali liquor is adjusted in flow by flow meter and regulating valve through circulating alkali liquor pump P101, and is transported to refrigeration system K301, heat storage system K401 and heating system K501 according to requirement.
[0017] The refrigeration system is used for cooling hydrogen and oxygen in the gas-liquid separation system. Refrigeration system K301 includes chilled water tank V301, chilled water circulating pump P301 and lithium bromide unit C301. The alkali liquor outlet of gas-liquid separation system K201 is connected with the pipe passage inlet of lithium bromide unit C301 through circulating alkali liquor pump P101, flow meter and regulating valve. The chilled water outlet of chilled water tank V301 is connected with the shell passage inlet of lithium bromide unit C301 through chilled water circulating pump P301. The shell passage outlet of lithium bromide unit C301 is connected with the chilled water inlet of gas-liquid separation system K201. The chilled water outlet of gas-liquid separation system K201 is connected with the chilled water inlet of chilled water tank V301. Refrigeration system K301 can adjust the chilled water return flow through the regulating valve of lithium bromide unit C301 outlet to match the load adjustment of hydrogen production device.
[0018] During the daytime electrolytic cell operation, high-temperature alkali liquor enters lithium bromide unit C301 through circulating alkali liquor pump P101, flow meter and regulating valve. The chilled water return water of chilled water tank V301 is transported to lithium bromide unit C301 through chilled water circulating pump P301. The high-temperature alkali liquor is used as heat source, and lithium bromide unit is used to produce chilled water of about 7-12 DEG C. The prepared chilled water is transported to gas-liquid separation system K201 to cool hydrogen and oxygen. The heat-exchanged chilled water return water returns to chilled water tank V301. If the prepared chilled water is reduced, it directly returns to chilled water tank V301 through the valve. The chilled water return water of chilled water tank V301 is transported to lithium bromide unit C301 to prepare chilled water through chilled water circulating pump P301. The refrigeration system K301 does not operate at night without light.
[0019] The heat storage system is responsible for recovering the heat in the remaining high-temperature lye. The heat storage system K401 comprises a cold water tank V401, a heat storage water tank V402, a heat storage water pump P401, and an electrolytic tank heat preservation heat exchanger E401. The lye outlet of the gas-liquid separation system K201 is connected to the tube-side inlet of the electrolytic tank heat preservation heat exchanger E401 through a lye circulating pump P101, a flow meter, and a regulating valve. The outlet of the cold water tank V401 is connected to the first shell-side inlet of the electrolytic tank heat preservation heat exchanger E401 through the heat storage water pump P401. The first shell-side outlet of the electrolytic tank heat preservation heat exchanger E401 is connected to the inlet of the heat storage water tank V402. The outlet of the heat storage water tank V402 is connected to the second shell-side inlet of the electrolytic tank heat preservation heat exchanger E401 through the heat storage water pump P401. The second shell-side outlet of the electrolytic tank heat preservation heat exchanger E401 is connected to the inlet of the cold water tank V401. Meanwhile, the other path of the lye circulating pump P101 is connected to the heat storage water inlet of the plant heating pipe network through a valve. The heat storage return water outlet of the plant heating pipe network is connected to the inlet of the cold water tank V401.
[0020] During the daytime when the electrolytic tank is running, the high-temperature lye enters the electrolytic tank heat preservation heat exchanger E401 through the lye circulating pump P101, the flow meter, and the regulating valve. Through the electrolytic tank heat preservation heat exchanger E401, the low-temperature water in the cold water tank V401 is heated to high-temperature hot water at about 70°C and stored in the heat storage water tank V402. At night when the electrolytic tank is not running, the hot water in the heat storage water tank V402 enters the electrolytic tank heat preservation heat exchanger E401 through the heat storage water pump P401 to heat the low-temperature lye for lye heat preservation, ensuring that the electrolytic system is maintained in a high-temperature state to protect the electrolytic tank and ensure the rapid start of the electrolytic tank. The hot water in the heat storage water tank V402 enters the plant heating pipe network through the heat storage water pump P401 to heat the plant, and the heat-exchanged 50°C hot water is stored in the cold water tank V401.
[0021] The heating system is used for heating the plant. The heating system K501 comprises a hot water tank V501, a hot water pump P501, and a heating heat exchanger E501. The lye outlet of the gas-liquid separation system K201 is connected to the tube-side inlet of the heating heat exchanger E501 through the lye circulating pump P101, the flow meter, and the regulating valve. The hot water outlet of the hot water tank V501 is connected to the shell-side inlet of the heating heat exchanger E501 through the hot water pump P501. The shell-side outlet of the heating heat exchanger E501 is connected to the inlet of the plant heating pipe network. The outlet of the plant heating pipe network is connected to the hot water inlet of the hot water tank V501. If the plant does not need to be heated, the shell-side outlet of the heating heat exchanger E501 is directly connected to the hot water inlet of the hot water tank V501 through a valve.
[0022] When the electrolytic cell is running in the daytime, the high-temperature alkali solution is pumped by the alkali solution circulating pump P101 into the heating heat exchanger E501 through the flow meter and the regulating valve. The high-temperature alkali solution exchanges heat with the hot water in the hot water tank V501 to form heating hot water at about 70℃. The heating hot water is returned to the hot water tank V501 through the plant heating pipe network. When there is no light at night, the heating system K501 does not run.
[0023] The tube side outlet of the lithium bromide unit C301, the tube side outlet of the electrolytic cell heat preservation heat exchanger E401 and the heating heat exchanger E501 can be directly returned to the electrolytic cell R101 through the switch valve, or can be transported to the electrolytic cell R101 through the air cooling system K601 after air cooling through the switch valve.
[0024] The alkali solution after heat exchange can be directly returned to the electrolytic cell R101 through the switch valve if the temperature is not high, or can be transported to the electrolytic cell R101 through the air cooling system K601 after air cooling through the switch valve if the temperature is high.
[0025] The air cooling system can remove the excess heat and maintain the heat balance of the hydrogen production system to ensure the stable operation of the electrolytic device when the plant does not need heating and the electrolytic cell does not need heat backup in summer, so that the remaining heat of the circulating alkali solution can be recovered.
[0026] The alkali solution waste heat flexible recovery system can be flexibly adjusted according to the seasonal changes and the different daily light intensities. In summer, when the plant does not need heating and the electrolytic cell does not need heat backup, the waste heat recovery system only runs the refrigeration system, and the air cooling system is responsible for removing the excess heat. In winter, in order to meet the needs of plant heating and electrolytic cell heat backup, the refrigeration system, the heating system and the heat storage system will run at the same time to ensure efficient use of energy.
Claims
1. A flexible alkali waste heat recovery system, characterized in that: The system includes an electrolytic cell (R101), a gas-liquid separation system (K201), a circulating alkali pump (P101), a refrigeration system (K301), a heat storage system (K401), and a heating system (K501). The alkali solution and gas mixture produced by the electrolytic cell (R101) are separated by the hydrogen separator and oxygen separator in the gas-liquid separation system (K201). The alkali solution is then circulated by the alkali circulating pump (P101) and its flow rate is regulated by a flow meter and a regulating valve, and then delivered to the refrigeration system (K301), the heat storage system (K401), and the heating system (K501), respectively.
2. The flexible alkali waste heat recovery system according to claim 1, characterized in that: The refrigeration system (K301) includes a chilled water tank (V301), a chilled water circulation pump (P301), and a lithium bromide unit (C301). The alkaline solution outlet of the gas-liquid separation system (K201) is connected to the tube-side inlet of the lithium bromide unit (C301) via the alkaline solution circulation pump (P101) through a flow meter and a regulating valve. The chilled water outlet of the chilled water tank (V301) is connected to the shell-side inlet of the lithium bromide unit (C301) via the chilled water circulation pump (P301). The shell-side outlet of the lithium bromide unit (C301) is connected to the chilled water inlet of the gas-liquid separation system (K201), and the chilled water outlet of the gas-liquid separation system (K201) is connected to the chilled water inlet of the chilled water tank (V301).
3. The flexible alkali waste heat recovery system according to claim 1, characterized in that: The heat storage system (K401) includes a cold water tank (V401), a hot water tank (V402), a hot water pump (P401), and an electrolytic cell heat exchanger (E401). The alkali outlet of the gas-liquid separation system (K201) is connected to the tube-side inlet of the electrolytic cell heat exchanger (E401) via an alkali circulation pump (P101) through a flow meter and a regulating valve. The outlet of the cold water tank (V401) is connected to the first shell-side inlet of the electrolytic cell heat exchanger (E401) via the hot water pump (P401). The outlet of the first shell side of the E401 is connected to the inlet of the hot water storage tank (V402). The outlet of the hot water storage tank (V402) is connected to the inlet of the second shell side of the electrolytic cell heat exchanger (E401) via the hot water storage pump (P401). The outlet of the second shell side of the electrolytic cell heat exchanger (E401) is connected to the inlet of the cold water tank (V401). Meanwhile, another branch of the alkali circulation pump (P101) is connected to the inlet of the heat storage water supply of the plant heating network via a valve. The outlet of the heat storage water return of the plant heating network is connected to the inlet of the cold water tank (V401).
4. The flexible alkali waste heat recovery system according to claim 1, characterized in that: The heating system (K501) includes a hot water tank (V501), a hot water pump (P501), and a heating heat exchanger (E501). The alkaline outlet of the gas-liquid separation system (K201) is connected to the tube-side inlet of the heating heat exchanger (E501) via an alkaline circulation pump (P101) through a flow meter and a regulating valve. The hot water outlet of the hot water tank (V501) is connected to the shell-side inlet of the heating heat exchanger (E501) via the hot water pump (P501). The shell-side outlet of the heating heat exchanger (E501) is connected to the inlet of the plant heating network, and the outlet of the plant heating network is connected to the hot water inlet of the hot water tank (V501).
5. The flexible alkali waste heat recovery system according to claim 4, characterized in that: The shell-side outlet of the heating heat exchanger (E501) is directly connected to the hot water inlet of the hot water tank (V501) via a valve.
6. The flexible alkali waste heat recovery system according to claim 2, characterized in that: The tube-side outlet of the lithium bromide unit (C301) returns to the electrolyzer (R101) via a switching valve, or is air-cooled by the air-cooling system (K601) via a switching valve and then transported to the electrolyzer (R101).
7. The flexible alkali waste heat recovery system according to claim 3, characterized in that: The tube-side outlet of the electrolytic cell heat exchanger (E401) returns to the electrolytic cell (R101) via a switching valve, or is air-cooled by the air-cooling system (K601) via a switching valve and then transported to the electrolytic cell (R101).
8. The flexible alkali waste heat recovery system according to claim 4, characterized in that: The heating heat exchanger (E501) returns to the electrolytic cell (R101) via a switch valve, or is sent to the electrolytic cell (R101) after being air-cooled by the air-cooling system (K601) via a switch valve.