Heat recovery and utilization system and micro-pressure steam heat energy unit

Abstract

The utility model discloses a heat recovery and utilization system and a micro-pressure steam heat energy unit, and an efficient heat energy recovery and reutilization loop is constructed through equipment such as an evaporator, a screw compressor, a condenser, an expansion valve and a flash tank. The evaporator absorbs heat from heat source water and evaporates a refrigerant into low-pressure gas, then high-temperature hot water is generated through the compression and condensation process, meanwhile, the flash tank is used for converting the high-temperature hot water into micro-pressure steam so as to meet the requirement for low-pressure steam in the system, by efficiently recycling and utilizing waste heat, the dependence of the system on external steam and electric power is reduced, and the energy consumption of the system is reduced. Therefore, energy efficiency is improved, operation cost is reduced, and energy waste and environmental influence are reduced.

Description

Technical Field

[0001] The utility model relates to the field of energy conservation, in particular to a heat recovery and utilization system and a micro-pressure steam thermal energy unit. Background Art

[0002] In oil mills and oil refining plants, multiple production processes require cooling using circulating water from cooling towers. This process consumes significant amounts of water resources and electricity, while also requiring significant amounts of heating steam, stripping steam, and motive steam for system operation. For example, processes such as fatty acid circulation cooling, final oil cooling, neutralization and decolorization vacuum, filter cake blowing steam, and refrigerator cooling all utilize circulating water from cooling towers for heat transfer and dissipation. Furthermore, processes such as neutralization, decolorization, and deodorization in the plant have high demands for thermal energy, requiring large quantities of hot water or low-pressure steam to meet process requirements. However, the significant amount of heat generated in the system is not effectively recycled, resulting in inadequate energy circulation between the cooling and heating stages. This results in high overall energy consumption, impacting energy efficiency and production economics.

[0003] Therefore, how to combine the heat energy required for cooling in the production process with the steam demand to achieve effective recovery of heat energy needs to be urgently addressed. Utility Model Content

[0004] In order to overcome the deficiencies of the prior art, the utility model provides a heat recovery and utilization system and a micro-pressure steam thermal energy unit that can combine the heat energy required for cooling in the production process with the steam demand to form an effective recovery of heat energy.

[0005] The technical solution adopted by the utility model to solve its technical problems is:

[0006] A heat recovery and utilization system includes an evaporator, a screw compressor, a condenser, an expansion valve, a flash tank and a water supply device;

[0007] The evaporator has a heat source water inlet and a heat source water outlet, and the heat source water and the liquid refrigerant are heat-exchanged through the evaporator, so that the liquid refrigerant evaporates into a low-pressure gaseous refrigerant;

[0008] The screw compressor is connected between the evaporator and the condenser, and is used to compress the low-pressure gaseous refrigerant into a high-pressure gaseous refrigerant;

[0009] The condenser is connected between the screw compressor and the expansion valve, and is used to exchange heat between the high-pressure gaseous refrigerant and softened water, condense the refrigerant into high-pressure liquid refrigerant, and generate high-temperature hot water;

[0010] The expansion valve is used to reduce the pressure of the high-pressure liquid refrigerant into a low-pressure liquid refrigerant, and allow the low-pressure liquid refrigerant to re-enter the evaporator;

[0011] The flash tank is connected to the condenser and is used to receive high-temperature hot water and generate low-pressure steam through flash evaporation;

[0012] The water replenishing device is connected to the condenser and is used to replenish the water in the system.

[0013] Furthermore, it also includes a high-temperature hot water output port and a micro-pressure steam output port, which are used to output the high-temperature hot water in the condenser and the micro-pressure steam generated in the flash tank respectively.

[0014] Furthermore, the temperature range of the generated high-temperature hot water is 85-120°C, or the temperature range of the produced micro-pressure steam is 105-120°C.

[0015] Furthermore, the pressure of the produced steam is 2.5 bar.

[0016] Furthermore, a water treatment device and a water pump are connected between the water replenishing device and the condenser. After being processed by the water treatment device, the replenishing water enters the condenser through the water pump.

[0017] Furthermore, the water treatment device is a softening water device, the output end of the softening water device is connected to the water pump, and the water pump transports the treated softened water to the condenser.

[0018] Furthermore, the evaporator, the screw compressor and the condenser are connected via a conduit, and a refrigerant is provided in the conduit.

[0019] Furthermore, the refrigerant is R245fa.

[0020] Furthermore, the temperature range of the heat source water is 45-85°C.

[0021] A low-pressure steam thermal energy unit comprises the above-mentioned heat recovery and utilization system.

[0022] The beneficial effects of the utility model are:

[0023] This utility model describes a heat recovery and utilization system and a low-pressure steam thermal energy unit. This system utilizes an evaporator, screw compressor, condenser, expansion valve, and flash tank to create a highly efficient heat recovery and reuse circuit. The evaporator absorbs heat from the heat source water and evaporates the refrigerant into a low-pressure gas. This gas is then compressed and condensed to generate high-temperature hot water. The flash tank simultaneously converts the high-temperature hot water into low-pressure steam to meet the system's low-pressure steam requirements. By efficiently recovering and utilizing waste heat, the system reduces its reliance on external steam and electricity, thereby improving energy efficiency and lowering operating costs while minimizing energy waste and environmental impact. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0025] Figure 1 It is a connection diagram of the utility model;

[0026] Figure 2 It is a connection diagram of the water replenishing device of the present utility model. DETAILED DESCRIPTION

[0027] The following will clearly and completely describe the concept, specific structure and technical effects of the present invention in combination with the embodiments and drawings, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by technical personnel in this field without creative work are within the scope of protection of the present invention. In addition, all the connection / connection relationships involved in the patent do not refer to the direct connection of components, but refer to the fact that a better connection structure can be formed by adding or reducing connection accessories according to the specific implementation situation. The various technical features in the creation of the present invention can be combined interactively without conflicting with each other.

[0028] A heat recovery and utilization system, referring to Figure 1 , including an evaporator 1, a screw compressor 2, a condenser 3, an expansion valve 4, a flash tank 5 and a water supply device 6.

[0029] Among them, the evaporator 1 has a heat source water inlet 11 and a heat source water outlet 12, and the heat source water and the liquid refrigerant are heat exchanged through the evaporator 1, so that the liquid refrigerant is evaporated into a low-pressure gaseous refrigerant; the screw compressor 2 is connected between the evaporator 1 and the condenser 3, and is used to compress the low-pressure gaseous refrigerant into a high-pressure gaseous refrigerant; the condenser 3 is connected between the screw compressor 2 and the expansion valve 4, and is used to heat exchange the high-pressure gaseous refrigerant with softened water, condense it into a high-pressure liquid refrigerant, and generate high-temperature hot water; the expansion valve 4 is used to reduce the pressure of the high-pressure liquid refrigerant to a low-pressure liquid refrigerant, and allow the low-pressure liquid refrigerant to re-enter the evaporator 1; the flash tank 5 is connected to the condenser 3, and is used to receive high-temperature hot water and generate micro-pressure steam through flash evaporation; the water replenishment device 6 is connected to the condenser 3, and is used to replenish the water in the system.

[0030] Among them, reference Figure 1 The thermal energy unit includes: an evaporator 1, a screw compressor 2, a condenser 3, an expansion valve 4, a flash tank 5 and a water supply device 6.

[0031] The utility model realizes multi-stage heat utilization by combining heat source water with a heat energy unit to form a heat recovery and utilization system. In the system, the make-up water is connected through the fatty acid circulation system, the final oil cooling system, the neutralization and decolorization vacuum condensation system, the filter cake steam condensation system, and the refrigerator cooling system. The make-up water exchanges heat with the condenser 3 of these systems, is cooled or condensed, and its heat energy is recovered to form heat source water. The heat source water and the liquid refrigerant exchange heat in the evaporator 1. After the liquid refrigerant evaporates into a gaseous state, it is sucked away by the screw compressor 2 and compressed into a high-temperature and high-pressure gaseous refrigerant. The high-temperature gaseous refrigerant exchanges heat with the make-up water in the condenser 3 to generate high-temperature hot water, which can be directly used in the workshop or formed into low-pressure steam through the flash tank 5 for use as a heat source or clean steam, thereby improving the overall energy efficiency of the system. The system combines the heat energy of cooling and heating to achieve energy saving and consumption reduction, thereby achieving environmental protection.

[0032] Wherein, the temperature range of the heat source water is 45-85°C.

[0033] In some embodiments, the system further includes a high-temperature hot water output port 7 and a low-pressure steam output port 8, which are used to output the high-temperature hot water in the condenser 3 and the low-pressure steam generated in the flash tank 5, respectively. Specifically, the high-temperature hot water output port 7 is connected to the condenser 3 for delivering the high-temperature hot water generated in the condenser 3 to external heat-using equipment; the low-pressure steam output port 8 is connected to the flash tank 5 for delivering the low-pressure steam generated in the flash tank 5 to external steam-using equipment. These two output ports can respectively meet the hot water and steam needs of different industrial applications, achieving efficient energy utilization and diversified output. Furthermore, the system can adjust the output hot water temperature and steam pressure as needed to adapt to different industrial application scenarios, further enhancing the system's flexibility and practicality.

[0034] Furthermore, the temperature range of the generated high-temperature hot water is 85-120°C, or the temperature range of the produced micro-pressure steam is 105-120°C.

[0035] Furthermore, the pressure of the produced steam is 2-4 bar, preferably 2.5 bar.

[0036] In some embodiments, reference Figure 2A water treatment device 61 and a water pump 62 are connected between the water replenishment device 6 and the condenser 3. After being treated by the water treatment device 61, the replenishment water enters the condenser 3 via the water pump 62. Furthermore, the water treatment device 61 is a water softening device, the output of which is connected to the water pump 62, which delivers the treated softened water to the condenser 3. Specifically, the water treatment device 61 softens the replenishment water, removing minerals and impurities from the water and preventing scale formation within the system, thereby improving system efficiency and lifespan. Softened water serves as a source of clean steam. Using softened water can generate high-quality, low-pressure steam, making it particularly suitable for use as stripping steam in the oil refining process. Furthermore, the softened water is delivered to the condenser 3 via the water pump 62, ensuring a sufficient amount of water in the condenser 3 to maintain efficient heat exchange. Furthermore, the combined use of the water treatment device 61 and the water pump 62 allows for automatic adjustment of the replenishment water volume based on system needs, enabling precise control and efficient management.

[0037] In some embodiments, the water treatment device 61 may also include, but is not limited to: a reverse osmosis device: used to further remove dissolved salts and organic matter from the water to ensure water purity, suitable for systems with high water quality requirements; a filter: which may include sand filtration, carbon filtration, or ultrafiltration, used to remove suspended particles, sediment, and impurities from the water, protecting the equipment in the system from particle clogging; an electrodeionization (EDI) system: which uses electrodeionization technology to further remove ions from the water to produce ultrapure water, suitable for applications with extremely high water quality requirements. It is understood that these devices can be used individually or in combination according to the specific needs of the system to ensure that the quality of the make-up water meets the system requirements.

[0038] In some embodiments, the evaporator 1, screw compressor 2, and condenser 3 are connected by a conduit, and a refrigerant is provided in the conduit, forming a closed circulation system for transmitting and converting thermal energy. In this circulation system, the refrigerant absorbs heat and evaporates into a gas in the evaporator 1. After entering the screw compressor 2 through the conduit and being pressurized, it becomes a high-temperature and high-pressure gas, and then enters the condenser 3. In the condenser 3, the refrigerant releases heat through heat exchange, condenses into a liquid, and flows back to the evaporator 1 through the conduit, completing the cycle. The sealing performance of this circulation system and the thermal insulation performance of the conduit are crucial to the efficiency and stability of the system, ensuring that the refrigerant does not leak or dissipate heat during transmission between different components.

[0039] Furthermore, the conduit can be made of high-strength corrosion-resistant materials, suitable for high-temperature and high-pressure environments, to improve the safety and durability of the system.

[0040] Furthermore, the refrigerant is R245fa or another environmentally friendly refrigerant with appropriate medium-pressure characteristics, ensuring efficient system operation at different temperatures and reducing environmental impact. R245fa is pentafluoropropane with a chemical formula of C3H3F5. It is environmentally friendly, has a moderate system pressure, and operates within a temperature range selected to optimize the working fluid's performance.

[0041] A micro-pressure steam thermal energy unit, comprising the above-mentioned heat recovery and utilization system, and also comprising a cloud-based intelligent platform. The cloud-based intelligent platform is connected to the thermal energy unit through a data acquisition and transmission module, which can realize remote real-time monitoring of the unit's operating status, view historical data and alarms at any time, and use big data analysis and intelligent diagnosis functions to comprehensively evaluate the unit's operating status. Through the cloud-based intelligent platform, users can grasp the operating parameters of the equipment (such as temperature, pressure, flow, etc.) in real time, and receive alarm notifications when an abnormality occurs, so as to facilitate timely maintenance measures. The platform also has a big data analysis function. Through the long-term accumulation and analysis of equipment operation data, it predicts the potential failure points of the equipment, realizes predictive maintenance, and avoids downtime caused by sudden failures. At the same time, the platform can provide optimization suggestions to help improve the efficiency and energy-saving effect of the unit, thereby ensuring the safe, stable and efficient operation of the unit. The platform can also be interconnected with other energy management systems to form an intelligent energy management network to achieve optimal allocation of overall energy resources.

[0042] A specific case analysis is given in the application of a micro-pressure steam thermal unit: a 1,000-ton / day refinery.

[0043] 1. Heat recovery system design:

[0044] S1. First stage heat recovery:

[0045] Heat is recovered through the cooling tower to produce hot water at 65-70℃.

[0046] S2. Second stage heat pump heating system:

[0047] The 65-70℃ hot water recovered in the first stage is heated by the secondary heat pump to 120℃, directly producing 2.5bar steam.

[0048] 2. Energy consumption and cost comparison are shown in Table 1 below:

[0049] Table 1. Comparison of energy consumption between the original system and the new system

[0050] System Category Original system New system (micro-pressure steam thermal energy unit) Steam consumption 2.385 tons No change Steam costs 200 yuan / ton 200 yuan / ton Heat pump unit power consumption none 580 KWh Cooling tower fan power consumption 60 KWh 60 KWh electricity bill 0.7 yuan / KWh 0.7 yuan / KWh

[0051] 3. Cost accounting:

[0052] T1. Original system cost:

[0053] Steam cost: 2.385 tons x 200 yuan / ton = 477 yuan / hour

[0054] Cooling tower fan power consumption cost: 60KWh × 0.7 yuan / KWh = 42 yuan / hour

[0055] Total cost (original system): 519 yuan / hour

[0056] T2. New system cost (micro-pressure steam thermal energy unit)

[0057] Steam cost: 2.385 tons x 200 yuan / ton = 477 yuan / hour

[0058] Heat pump unit power consumption cost: 580KWh × 0.7 yuan / KWh = 406 yuan / hour

[0059] Cooling tower fan power consumption cost: 60KWh × 0.7 yuan / KWh = 42 yuan / hour

[0060] Total cost (new system): 406 yuan / hour

[0061] T3. Cost savings:

[0062] Hourly cost savings = total cost of the original system - total cost of the new system

[0063] Cost savings per hour = 519 yuan - 406 yuan = 113 yuan / hour

[0064] 4. Summary:

[0065] Through the application of micro-pressure steam thermal energy units, the factory saves 113 yuan per hour under the same steam consumption and output conditions, achieving more efficient energy utilization.

[0066] The above is a specific description of the preferred implementation of the present invention, but the invention of the present invention is not limited to the embodiments. Those skilled in the art can make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A heat recovery and utilization system, comprising an evaporator, a screw compressor, a condenser, an expansion valve, a flash tank and a water supply device, characterized in that: The evaporator has a heat source water inlet and a heat source water outlet, and the heat source water and the liquid refrigerant are heat-exchanged through the evaporator, so that the liquid refrigerant evaporates into a low-pressure gaseous refrigerant; The screw compressor is connected between the evaporator and the condenser, and is used to compress the low-pressure gaseous refrigerant into a high-pressure gaseous refrigerant; The condenser is connected between the screw compressor and the expansion valve, and is used to exchange heat between the high-pressure gaseous refrigerant and softened water, condense the refrigerant into high-pressure liquid refrigerant, and generate high-temperature hot water; The expansion valve is used to reduce the pressure of the high-pressure liquid refrigerant into a low-pressure liquid refrigerant, and allow the low-pressure liquid refrigerant to re-enter the evaporator; The flash tank is connected to the condenser and is used to receive high-temperature hot water and generate low-pressure steam through flash evaporation; The water replenishing device is connected to the condenser and is used to replenish the water in the system.

2. The heat recovery and utilization system according to claim 1, characterized in that: It also includes a high-temperature hot water output port and a micro-pressure steam output port, which are used to output the high-temperature hot water in the condenser and the micro-pressure steam generated in the flash tank respectively.

3. The heat recovery and utilization system according to claim 2, characterized in that: The temperature range of the generated high-temperature hot water is 85-120°C, or the temperature range of the produced micro-pressure steam is 105-120°C.

4. The heat recovery and utilization system according to claim 2, characterized in that: The pressure of the produced steam is 2.5 bar.

5. The heat recovery and utilization system according to claim 1, characterized in that: A water treatment device and a water pump are connected between the water replenishing device and the condenser. After being processed by the water treatment device, the replenishing water enters the condenser through the water pump.

6. The heat recovery and utilization system according to claim 5, characterized in that: The water treatment device is a softening water device, the output end of the softening water device is connected to the water pump, and the water pump transports the treated softened water to the condenser.

7. The heat recovery and utilization system according to claim 1, characterized in that The evaporator, the screw compressor and the condenser are connected via a conduit, and a refrigerant is arranged in the conduit.

8. The heat recovery and utilization system according to claim 7, characterized in that: The refrigerant is R245fa.

9. The heat recovery and utilization system according to claim 1, characterized in that: The temperature range of the heat source water is 45-85°C.

10. A micro-pressure steam thermal energy unit, characterized in that: The heat recovery and utilization system comprises the heat recovery and utilization system according to any one of claims 1 to 9.

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