Stepped countercurrent sectional heat exchange device and water heater thereof

Abstract

The invention relates to the technical field of heat exchangers, and provides a stepped countercurrent segmented heat exchange device and application of a water heater thereof.The stepped countercurrent segmented heat exchange device comprises a heat exchange body, and the heat exchange body comprises a heat exchange area and a heat exchange pipeline; the heat exchange area is provided with a plurality of sections, the plurality of sections of heat exchange area are mutually communicated and mutually independently arranged at intervals, and heat exchange pipelines which are mutually connected are arranged in each section of heat exchange area; the heat exchange pipeline is provided with a heat insulation pipe used for preventing heat transfer from being generated between two adjacent heat exchange areas, so that cold fluid and hot fluid of each heat exchange area can achieve non-interference and independent heat exchange in the heat exchange process, each heat exchange area forms heat transfer separation through the heat insulation pipe, and stepped temperature difference is formed between the heat exchange areas. The segmented design of the heat exchange area avoids the problem of overall temperature difference homogenization caused by heat diffusion of a traditional device, the heat exchange pipeline independently completes efficient heat exchange in each segment of the heat exchange area, and the overall heat exchange efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of heat exchangers, and particularly to a stepped countercurrent segmented heat exchange device and a water heater thereof; by changing the flow groove pipes or pipeline designs of cold and hot fluids, it can also be used in the heat exchange fields of various fluids or gases. Background Art

[0002] Various shower water heaters used in modern society are devices with relatively high household energy consumption, and their power is generally 2.5KW - 8.5KW and above. Taking each person's 5-minute shower, using 30 liters of water, and heating the average water temperature by 30°C, that is: heat capacity 4200J × mass 30Kg × temperature 30K ÷ 3600J.S = 1050W. For an instant water heater, the instantaneous power must be 12.6KW; for a storage water heater, it needs to be pre-heated and insulated in advance, resulting in more heat energy loss; at the same time, it seriously affects the power grid load, and both households and power plants are discharging heat, polluting the environment.

[0003] Existing air energy water heaters have reduced energy efficiency in environments that require heating more in low-temperature weather, and about 3KW of electric auxiliary heating is required. Due to the generally used outdoor storage water tank and water supply pipeline of more than 100 liters, the temperature difference is large, the temperature drops quickly, and it needs to run intermittently for heat preservation, resulting in high energy consumption, mechanical noise and wear, limited service life, and high production, installation and maintenance costs.

[0004] Other heat exchange energy-saving devices take effect slowly. Because the heat exchange heat regeneration ratio lags behind the heat energy output, the time required for water to conduct heat exchange through a metal pipe medium = water heat capacity × mass × temperature ÷ heat conduction power (temperature difference × heat conduction rate × heat conduction area ÷ heat conduction distance × metal heat conduction efficiency). Hot water needs to be pre-heated in advance to meet the instantaneous heat output, and it is impossible to reduce the heating power of the water heater; for example, for a shower time of about 5 minutes / 30 liters of water, it may stop using before reaching the designed heat exchange efficiency, and the heat energy of the hot waste water needs to be discharged without being utilized, and leaving it will also cause heat dissipation and temperature drop, resulting in losses, and the energy-saving effect is poor. For an infinitely long heat preservation exchange area, the heat exchange efficiency is 100% (materials also consume heat energy and cannot be achieved), that is, the output energy = the input energy, with a 30°C temperature difference, the same mass of water, the cold water is heated by 15°C, and the hot water is cooled by 15°C. The actual heat regeneration efficiency ≤ 0.5 (because of heat dissipation loss during long-term soaking, and the direct mixing has a short time and high efficiency).

[0005] Such as Figure 1 the straight pipe or annular pipe heat exchange device, its heat exchange speed is slow. If the efficiency is to be improved, the exchange area needs to be lengthened, the volume is large, and the heat loss is also large; Figure 2 the parallel pipe heat exchange device uses a lot of metal materials, has fast heat conduction, is difficult to form a temperature difference between the water inlet and outlet ends, and has low efficiency; Figure 3 the plate heat exchange device has a large area, needs to increase the material strength to withstand the water pressure, is difficult to clean and maintain, and the efficiency gradually decreases; Figure 4Due to manufacturing technology limitations, the spiral pipe heat exchange device has a large bending diameter, a large volume of the outer groove pipe of the pipe, a long hydrothermal exchange time with the center of the circle, low efficiency, and is difficult to clean and maintain.

[0006] In the existing countercurrent heat exchange device, since the liquid flows longitudinally in the exchange area in opposite directions, and at the same time, the directions of liquid flow, liquid heat conduction, and heat conduction of the heat exchange pipe are all longitudinally opposite to each other in the exchange area, the high- and low-temperature fluids flow out of the exchange area within a few seconds. The time is short and 100% heat exchange cannot be achieved. The temperature of the high-temperature fluid outlet is higher than that of the low-temperature fluid outlet; if the time is long, the temperature in the exchange area is consistent, and 100% heat exchange can be achieved. The outlet temperatures of the high- and low-temperature fluids are the same, that is, each obtains a 50% temperature rise and fall of the temperature difference. Therefore, the heat regeneration rate cannot exceed 0.5.

[0007] If the exchange area is increased to an infinite length, the flow rate is stabilized to an appropriate speed, and low-thermal-conductivity materials are selected for the heat exchange pipe and the exchange water tank, it is possible to achieve a higher temperature at the outlet of the low-temperature fluid than at the outlet of the high-temperature fluid, but the heat exchange power is low, the volume is large, and the heat recovery amount is small, which has no practical value; when the flow rate is unstable, 100% heat exchange cannot be achieved, and the stable heat regeneration rate of 0.5 cannot be exceeded. Summary of the Invention

[0008] The present invention provides a stepped countercurrent segmented heat exchange device and a water heater thereof. In the stepped countercurrent segmented heat exchange device, a plurality of heat exchange zones are arranged in the heat exchange main body in a communicating and mutually independent and spaced manner. Each heat exchange zone is provided with a heat exchange pipe. The heat transfer between adjacent two heat exchange zones is separated by an adiabatic pipe, ensuring that each heat exchange zone forms an independent temperature zone, thereby establishing a stepped temperature difference. The segmented design of the heat exchange zone avoids the problem of overall temperature difference equalization caused by heat diffusion in the traditional device. The cold and hot fluids independently complete efficient heat exchange in each heat exchange zone, and each heat exchange zone does not interfere with each other, significantly improving the overall heat exchange efficiency.

[0009] A stepped countercurrent segmented heat exchange device designed according to this purpose includes a heat exchange main body, and the heat exchange main body includes a heat exchange zone for heat exchange between cold and hot fluids; The heat exchange zone is provided with a plurality of segments, and the plurality of heat exchange zones are communicated with each other and arranged in a mutually independent and spaced manner. Each heat exchange zone is provided with heat exchange pipes connected to each other, and a cold fluid flow gap is formed between the heat exchange zone and the heat exchange pipes; An adiabatic pipe for preventing heat transfer between adjacent two heat exchange zones is provided on the heat exchange pipe, so that the cold and hot fluids in each heat exchange zone do not interfere with each other and perform independent heat exchange during the heat exchange process, and each heat exchange zone forms a heat transfer separation through the adiabatic pipe, and a stepped temperature difference is formed between each heat exchange zone.

[0010] The adiabatic pipe is arranged at the connection between adjacent two heat exchange zones.

[0011] The hot fluid flows forward in sequence along each heat exchange zone, and the cold fluid flows in the opposite direction to the hot fluid in the heat exchange pipeline, so that a stepped countercurrent segmented heat exchange is formed between the cold and hot fluids on each heat exchange zone.

[0012] A transverse heat exchange zone and a longitudinal heat exchange zone are provided between each heat exchange zone and the heat exchange pipeline. The heat exchange pipeline is arranged in a circuitous manner on each heat exchange zone to effectively increase the transverse heat conductivity of the transverse heat exchange zone in each heat exchange zone and relatively reduce the longitudinal heat conductivity of the longitudinal heat exchange zone in each heat exchange zone, so that a gradient temperature difference from high to low is formed in the reverse fluid in each heat exchange zone.

[0013] The heat exchange pipelines between two adjacent heat exchange zones are connected by an insulating pipe made of insulating material or material with low heat conductivity.

[0014] A number of partitions are provided in the heat exchange main body. One end of the partition is connected to the inner side of the heat exchange main body, and a flow-limiting gap is provided between the other end of the partition and the heat exchange main body, so that the heat exchange main body is divided into a number of heat exchange zones that are connected to each other and are arranged at independent intervals through a number of partitions.

[0015] A heat exchange zone in the shape of a water tank is formed between the inner side of the heat exchange main body and the partition. The flow-limiting gap at the connection between two adjacent heat exchange zones forms a reduced-section flow-limiting heat preservation design. The flow-limiting gap forms a small-area transition zone for the hot fluid to enter another heat exchange zone from the heat exchange zone. The flow-limiting gap is used to maintain the temperature difference during the transition connection between each heat exchange zone and to maintain the stepped temperature difference between each heat exchange zone.

[0016] A stable water level flow-limiting device is provided on the heat exchange main body. The stable water level flow-limiting device includes a water retaining ring that extends upward along the upper direction of the heat exchange main body and forms a block to slow down the discharge flow rate of the hot fluid. A drainage channel for discharging waste water is provided in the water retaining ring. The drainage channel penetrates the water retaining ring up and down, and a drainage port is provided on one side at the upper part of the water retaining ring.

[0017] The heat exchange main body includes a seat body and a cover body covering the seat body. The partition and the seat body are respectively sealed and cooperated with the cover body through a sealing member, so that only adjacent two heat exchange zones are connected to each other through the flow-limiting gap; A heat preservation and heat insulation layer is provided on the periphery of the seat body and on the partition. The heat preservation and heat insulation layer and the insulating pipe form a heat preservation and heat insulation device of the heat exchange main body, so that each heat exchange zone does not interfere with each other and conducts independent heat exchange, and maintains the heat exchange efficiency and the instantaneous state of stabilizing the temperature of each heat exchange zone when the flow rate of the hot fluid is unstable. There will be no phenomenon that heat energy is transferred between each heat exchange zone to cause a decrease in temperature difference; An inlet for guiding the hot fluid into the heat exchange zone is provided on the cover body.

[0018] A water heater designed for this purpose includes a water heater main body, and the above-mentioned stepped countercurrent segmented heat exchange device is provided on the water heater main body. The heat exchange main body is arranged at the lower part of the water heater main body and is used to collect the hot fluid output by the water heater main body.

[0019] The beneficial technical effects of the present invention are as follows: In the stepped countercurrent segmented heat exchange device, several heat exchange zones are arranged in the heat exchange main body to be communicated with each other and are arranged at independent intervals. Each heat exchange zone is provided with a heat exchange pipeline, and the heat transfer between adjacent two heat exchange zones is separated by the cooperation of the heat insulation pipe, ensuring that each heat exchange zone forms an independent temperature zone, thereby establishing a stepped temperature difference. The segmented design of the heat exchange zone avoids the problem of overall temperature difference equalization caused by heat diffusion in the traditional device. The cold and hot fluids independently complete efficient heat exchange in each heat exchange zone, and each heat exchange zone does not interfere with each other, significantly improving the overall heat exchange efficiency. Description of the Drawings

[0020] Figure 1 It is a straight pipe or annular pipe heat exchange device of the prior art.

[0021] Figure 2 It is a parallel pipe heat exchange device of the prior art.

[0022] Figure 3 It is a plate heat exchange device of the prior art.

[0023] Figure 4 It is a spiral pipe heat exchange device of the prior art.

[0024] Figure 5 It is a schematic plan view of the stepped countercurrent segmented heat exchange device according to an embodiment of the present invention.

[0025] Figure 6 It is a schematic structural view of the tortuous arrangement of the heat exchange pipeline according to an embodiment of the present invention.

[0026] Figure 7 It is a schematic three-dimensional view of the stable water level current limiting device according to an embodiment of the present invention.

[0027] Figure 8 It is a schematic structural view of the cover body according to an embodiment of the present invention.

[0028] Figure 9 It is a segmented adiabatic conduction heat exchange curve graph of the stepped countercurrent segmented heat exchange device according to an embodiment of the present invention.

[0029] Figure 10 It is an ideal heat exchange state that conforms to the law of conservation of energy according to an embodiment of the present invention.

[0030] Figure 11Schematic diagram of the heat exchange structure of the cold and hot fluids of the stepped countercurrent segmented heat exchange device according to an embodiment of the present invention.

[0031] Figure 12 Schematic diagram of the heat exchange structure of the cold and hot fluids of the stepped countercurrent segmented heat exchange device according to an embodiment of the present invention from another perspective.

[0032] Figure 13 Schematic diagram of the heat exchange curve structure of the cold and hot fluids of the stepped countercurrent segmented heat exchange device according to an embodiment of the present invention.

[0033] Figure 14 Schematic diagram of the three-dimensional structure of the stepped countercurrent segmented heat exchange device according to an embodiment of the present invention applied to a water heater.

[0034] Figure 15 Schematic diagram of the planar structure of the stepped countercurrent segmented heat exchange device according to an embodiment of the present invention applied to a water heater.

[0035] Figure 16 Schematic diagram of the three-dimensional structure of the stepped countercurrent segmented heat exchange device according to an embodiment of the present invention applied to a water heater from another perspective, and the schematic diagram of the structure where the cover body is separated from the seat body.

[0036] Figure 17 Heat exchange curve graph of the first liquid and the second liquid with the same reverse flow rate in the liquid heat exchange device of the present invention when they conduct heat to no temperature difference with each other.

[0037] Figure 18 Curve graph of the present invention when initially used or restarted after a long-term stop, when the first liquid fills the first heat exchange area.

[0038] Figure 19 Curve graph of the present invention when the first liquid fills each heat exchange area.

[0039] Figure 20 Curve graph of the present invention when the liquid heat exchange device of the water heater stops using after continuous and stable use. Detailed implementation manners

[0040] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. In order to make the above objects, features, and advantages of the present application more obvious and understandable, many specific details are set forth in the following description for a thorough understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0041] See Figures 5 - 20 , a stepped countercurrent segmented heat exchange device, comprising a heat exchange main body 1, wherein the heat exchange main body 1 includes a heat exchange area 2 for heat exchange between cold and hot fluids; The heat exchange area 2 is provided with several segments, and the several segments of the heat exchange area 2 are communicated with each other and are arranged at independent intervals. Heat exchange pipes 3 connected to each other are arranged in each segment of the heat exchange area 2, and a heat fluid flow gap is formed between the heat exchange area 2 and the heat exchange pipes 3; An adiabatic pipe 4 for preventing heat transfer between adjacent two segments of the heat exchange area 2 is arranged on the heat exchange pipe 3, so that the cold and hot fluids in each segment of the heat exchange area 2 can achieve non-interference and independent heat exchange during the heat exchange process, and each segment of the heat exchange area 2 forms a heat transfer separation through the adiabatic pipe 4, and a stepped temperature difference is formed between each segment of the heat exchange area 2.

[0042] In the stepped countercurrent segmented heat exchange device, several segments of the heat exchange area 2 are arranged in the heat exchange main body 1 to be communicated with each other and are arranged at independent intervals. Each segment of the heat exchange area 2 is provided with a heat exchange pipe 3, and the heat transfer separation of the adjacent two segments of the heat exchange area 2 is coordinated with the adiabatic pipe 4 to ensure that each segment of the heat exchange area 2 forms an independent temperature zone, thereby establishing a stepped temperature difference. The segmented design of the heat exchange area 2 avoids the problem of overall temperature difference equalization caused by heat diffusion in the traditional device. The cold and hot fluids independently complete efficient heat exchange in each segment of the heat exchange area 2, and each segment of the heat exchange area 2 does not interfere with each other, significantly improving the overall heat exchange efficiency.

[0043] The adiabatic pipe 4 can effectively prevent heat transfer between adjacent heat exchange areas 2, ensuring that the cold and hot fluids in each segment of the heat exchange area 2 complete efficient heat exchange in an independent space. This segmented design enables each segment of the heat exchange area 2 to form an independent temperature gradient, forming a stepped temperature difference as a whole, thereby significantly improving the heat exchange efficiency, making the heat exchange process more stable and controllable, and ensuring that the temperature states of each segment of the heat exchange area 2 are not interfered.

[0044] The adiabatic pipe 4 is arranged at the connection between two adjacent heat exchange areas 2.

[0045] By arranging the adiabatic pipe 4 at the connection of adjacent heat exchange areas 2, the heat transfer through the connection area can be accurately blocked. This layout ensures that when the cold and hot fluids perform heat exchange in different heat exchange areas 2, the heat conduction paths between each segment are physically isolated, thereby maintaining the independent temperature difference of each segment of the heat exchange area 2. The position design of the adiabatic pipe 4 takes into account the continuity of fluid flow and the effectiveness of heat blocking, avoiding the problem of overall temperature difference convergence caused by heat conduction in the connection area in the traditional structure, and further strengthening the design goal of the stepped temperature difference.

[0046] The hot fluid flows forward in sequence along each heat exchange zone 2, and the cold fluid flows in the opposite direction to the hot fluid in the heat exchange pipe 3, so that a stepped countercurrent segmented heat exchange is formed between the cold and hot fluids on each heat exchange zone 2.

[0047] Through the design of the forward flow of the hot fluid and the reverse countercurrent of the cold fluid in the heat exchange pipe 3, the cold and hot fluids form the maximum temperature difference contact in each heat exchange zone 2, significantly improving the heat exchange efficiency. The countercurrent flow mode enables the high-temperature hot fluid and the low-temperature cold fluid to conduct efficient heat exchange in each heat exchange zone 2. As the flow progresses, a temperature gradient is gradually formed, and the segmented design further decomposes the overall temperature difference into multiple stepped temperature differences. This synergistic effect not only prolongs the effective heat exchange time but also ensures the stability of the temperature difference in each heat exchange zone 2 through staged heat exchange.

[0048] A transverse heat exchange zone 5 and a longitudinal heat exchange zone 6 are provided between each heat exchange zone 2 and the heat exchange pipe 3. The heat exchange pipe 3 is arranged in a meandering manner on each heat exchange zone 2 to effectively increase the transverse heat conductivity of the transverse heat exchange zone 5 in each heat exchange zone 2 and relatively reduce the longitudinal heat conductivity of the longitudinal heat exchange zone 6 in each heat exchange zone 2, so that the reverse fluid in each heat exchange zone 2 forms a gradient temperature difference from high to low.

[0049] The division of the transverse heat exchange zone 5 and the longitudinal heat exchange zone 6 combined with the meandering arrangement of the heat exchange pipe 3 significantly increases the transverse heat transfer area. At the same time, the longitudinal heat conductivity is reduced by reducing the longitudinal flow path length. This design enables the cold and hot fluids to fully contact in the transverse heat exchange zone 5, and the heat is quickly transferred horizontally. The metal pipe in the longitudinal heat exchange zone 6 has a long distance and slow heat conduction, maintaining a large stepped temperature difference longitudinally and reducing heat conduction. Thus, a gradient temperature difference from high to low is formed in each heat exchange zone 2, effectively avoiding temperature homogenization. At the same time, the meandering pipe enhances fluid disturbance, further improving the heat exchange efficiency.

[0050] The heat exchange pipes 3 between two adjacent heat exchange zones 2 are connected by an insulating pipe 4 made of insulating material or material with low heat conductivity.

[0051] Using an insulating material or a material with low heat conductivity to make the insulating pipe 4 between adjacent heat exchange zones 2 can block the longitudinal transfer of heat through the pipe wall at the material level. This design not only reduces heat loss but also ensures that the temperature difference in each heat exchange zone 2 is independently controllable. The material selection and structural design of the insulating pipe 4 work together to solve the problem of segmented temperature difference failure caused by heat conduction of traditional metal pipes, enabling the stepped temperature difference to be maintained for a long time, especially suitable for high-temperature or large-temperature-difference application scenarios.

[0052] A plurality of partition plates 7 are provided inside the heat exchange main body 1. One end of the partition plate 7 is connected to the inner side of the heat exchange main body 1, and a current-limiting gap 8 is provided between the other end of the partition plate 7 and the heat exchange main body 1, so that the heat exchange main body 1 is divided into several heat exchange zones 2 that communicate with each other and are arranged at independent intervals through the plurality of partition plates 7.

[0053] A heat exchange zone 2 in the shape of a water tank is formed between the inner side of the heat exchange main body 1 and the partition plate 7. The current-limiting gap 8 at the communication part between two adjacent heat exchange zones 2 forms a reduced cross-section current-limiting heat preservation design. The current-limiting gap 8 forms a small-area transition zone for the hot fluid to enter another heat exchange zone 2 from the heat exchange zone 2. The current-limiting gap 8 is used to maintain the temperature difference when the heat exchange zones 2 in each section are connected in transition, and is used to maintain the stepped temperature difference between the heat exchange zones 2 in each section.

[0054] The partition plate 7 divides the heat exchange main body 1 into multiple independent heat exchange zones 2. The design of the current-limiting gap 8 limits the liquid flow cross-sectional area between adjacent regions while ensuring the continuous flow of the fluid. The physical isolation effect of the partition plate 7 effectively reduces the direct heat conduction between the heat exchange zones 2, and the small cross-section design of the current-limiting gap 8 reduces the longitudinal transfer of heat through the liquid itself by restricting the fluid flow cross-sectional area. This structure not only maintains the connectivity of the overall flow channel, but also realizes the physical isolation of the segmented temperature difference, ensuring the independent working state of each heat exchange zone 2.

[0055] The reduced cross-section current-limiting heat preservation design formed by the water tank-shaped heat exchange zone 2 and the current-limiting gap 8 restricts the flow cross-sectional area of the fluid transition region, increases the flow velocity, and reduces the transition heat exchange rate between adjacent heat exchange zones 2. The current-limiting gap 8, as a small-area transition zone, allows the fluid to flow along a predetermined path and reduces the longitudinal transfer of heat with the fluid migration through the flow velocity control. This design maximally maintains the temperature difference between the heat exchange zones 2 in each section while ensuring the continuous operation of the system.

[0056] A stable water level current-limiting device 9 is provided on the heat exchange main body 1. The stable water level current-limiting device 9 includes a water retaining ring 10 that extends upward along the heat exchange main body 1 and forms a block to slow down the discharge flow rate of the hot fluid. A drainage channel 11 for discharging waste water is provided inside the water retaining ring 10. The drainage channel 11 penetrates the water retaining ring 10 up and down, and a drainage port 12 is provided on one side of the upper part of the water retaining ring 10.

[0057] The stable water level current-limiting device 9 slows down the discharge speed of the hot fluid through the water retaining ring 10 to ensure the stable water level in the heat exchange zone 2. The combined design of the drainage channel 11 and the drainage port 12 precisely controls the fluid discharge rate and prevents temperature fluctuations caused by sudden changes in flow rate. This structure can still maintain the water level balance of each heat exchange zone 2 when the fluid flow rate is unstable, avoid the decrease in heat exchange efficiency caused by water level changes, and further consolidate the stepped temperature difference through the current-limiting effect.

[0058] The heat exchange main body 1 includes a base body 13 and a cover body 14 covering the base body 13. The partition plate 7 and the base body 13 are respectively in sealed cooperation with the cover body 14 through sealing members, so that only the adjacent two heat exchange zones 2 communicate with each other through the flow-limiting notch 8; A heat insulation layer is provided on the peripheral side of the base body 13 and on the partition plate 7. The heat insulation layer and the heat insulation pipe 4 form a heat insulation device of the heat exchange main body 1, so that each heat exchange zone 2 does not interfere with each other and conducts independent heat exchange, and when the flow rate of the hot fluid is unstable, the heat exchange efficiency is maintained and the instantaneous state of the temperature of each heat exchange zone 2 is stabilized. There will be no phenomenon that the heat energy is transmitted between each heat exchange zone 2 to cause the temperature difference to decrease; The cover body 14 is provided with a water inlet 15 for guiding the hot fluid into the heat exchange zone 2.

[0059] The sealed cooperation between the base body 13 and the cover body 14 and the design of the heat insulation layer block the heat interference of the external environment from the overall structure, and at the same time ensure that the adjacent heat exchange zones 2 are only connected through the flow-limiting notch 8. The combination of the sealing member and the partition plate 7 completely eliminates the risk of fluid cross-flow and leakage. The heat insulation layer and the heat insulation pipe 4 cooperate to form multiple heat insulation barriers. This design can still maintain the instantaneous stability of the temperature of each section when the flow rate of the hot fluid fluctuates, and eliminates the temperature difference loss caused by structural heat conduction or environmental heat dissipation.

[0060] A water heater includes a water heater main body 16. The above-mentioned stepped countercurrent segmented heat exchange device is provided on the water heater main body 16. The heat exchange main body 1 is arranged at the lower part of the water heater main body 16 and is used for collecting the hot fluid output by the water heater main body 16.

[0061] Integrating the stepped countercurrent segmented heat exchange device at the lower part of the water heater main body 16 can efficiently recover and utilize the high-temperature waste heat discharged from the water heater. One end of the heat exchange pipe 3 is connected to the tap water pipe, and the other end is connected to the heating device. The tap water entering the heat exchange pipe 3 exchanges heat with the high-temperature waste hot water discharged from the water heater and then enters the heating device for heating, reducing the heating time and improving the energy efficiency.

[0062] With hot water (heat capacity 4200 J / Kg.℃, thermal conductivity 0.59 W / m.K) at a temperature of 40℃, cold water at 10℃, and a consistent flow rate of 6L / minute. The heat exchange pipe material is copper (heat capacity 390 J / Kg.℃, thermal conductivity about 400W / m.K), or stainless steel (heat capacity 500 J / Kg.℃, thermal conductivity about 16W / m.K). The outer diameter of the pipe is 20mm and the inner diameter is 18mm. Through experimental testing: Taking the traditional countercurrent heat exchange device as an example, when the reverse water flow passes through a straight or large arc smooth pipe and exchanges heat with a low-flow immersion water tank until 100%, it takes more than 60 seconds. When the reverse water flow uses a stirring forward method for heat exchange until 100%, it takes more than 7 seconds, depending on the stirring intensity. Since the metal cross-sectional area of the pipe is the same as the perimeter area, and the longitudinal and transverse thermal conductivities are the same, there is currently no suitable manufacturing material in reality that only has high transverse thermal conductivity, low longitudinal thermal conductivity, or no thermal conductivity. The heat capacity of water is higher than that of steel or copper (4200J÷500J or 390J), approximately 10 times. That is, the time required to heat and cool water is about 10 times more than that of steel or copper. The thermal conductivity of steel or copper is much higher than that of water. Therefore, when exchanging heat laterally to the water at a distance of 9mm from the pipe center and 9mm from the outer diameter, the copper pipe has longitudinally conducted heat to a distance of (400W / 0.59W*18mm)=12203mm with the same amount of heat. At the same time of heat exchange, water also transfers heat in all directions at the same thermal conductivity. The heat transferred by the longitudinal reverse fluid flow is always much greater than the heat transferred by the lateral heat exchange. The heat energy quickly diffuses and transfers to the large temperature difference area, causing the temperature in the heat exchange area to be close to the same (6L×40℃+6L×10℃)÷(6L+6L)=25℃. When the hot and cold water exchanges heat to 25℃ without temperature difference, the energy exchange stops, and no more heat energy is output or absorbed, and it is impossible to break through 100% (i.e., 50% of the total temperature difference for heating and cooling) physical heat exchange efficiency. Moreover, the above various exchange areas are designed to be smooth and flat, the water flow is stable without impact, tumbling, or stirring, and the heat exchange speed is slow. When the water is filled, when the 100% heat exchange reaches no temperature difference inside and outside the pipe and stops, the outlet water temperatures at both ends are infinitely close to 25℃. The heat recovery efficiency = temperature rise (25℃ - cold water 10℃) / temperature difference (hot water 40℃ - cold water 10℃)=0.5. When the flow rate is high, the heat exchange time is insufficient and the efficiency is lower. It is impossible to exceed 50% of the temperature difference heat exchange efficiency, and it is impossible to achieve the temperature interchange of the two, and it is impossible to approach the ideal heat exchange state that conforms to the law of conservation of energy, as Figure 10 shown.

[0063] When two liquids with different temperatures of the same mass are directly mixed for 100% heat exchange, only 50% heat exchange efficiency can be obtained for each. For example, when changing 100℃ to 50℃ output and 0℃ to 50℃ output, the efficiency is 0.5, and it is impossible to achieve Figure 10 the shown effect. For example, for two cups of water with the same mass and a temperature difference of 100℃, one is hot at 100℃ and the other is cold at 0℃. When the two cups are poured together for 100% heat exchange, two cups of water at 50℃ are obtained, with 50% temperature rise and fall for each.

[0064] If the total temperature difference is partitioned into three sections of heat preservation and adiabatic exchange using a stepped temperature difference, and three cups are arranged in the order of high temperature → empty middle cup → low temperature, the exchange process is not affected by heat conduction interference and heat dissipation loss, and the exchange is carried out in sections and sub - times. Pour 0.5 cups of water from each of the high - temperature and low - temperature cups into the empty middle cup for 100% heat exchange, (100°C + 0°C)÷2 = 50°C. The process is equivalent to the high temperature flowing towards the low temperature direction and the low temperature flowing towards the high temperature direction, which are reverse to each other. The temperature of the water in the middle cup is 50°C. Then pour 0.5 cups of water from the middle cup into the high - temperature and low - temperature cups respectively for 100% heat exchange. After the exchange, the temperature of the high - temperature cup is (100°C + 50°C)÷2 = 75°C, and the temperature of the low - temperature cup is (50°C + 0°C)÷2 = 25°C. Then pour 0.5 cups of water from each of the high - temperature and low - temperature cups into the middle cup, (75°C + 25°C)÷2 = 50°C. The process is also reverse. At this time, the water in the low - temperature cup is 25°C → the water in the middle cup is 50°C → the water in the high - temperature cup is 75°C, that is, the water at 0°C is heated to 75°C after three - stage exchange; the water in the high - temperature cup is 100°C → the water in the middle cup is 50°C → the water in the low - temperature cup is cooled to 25°C, that is, the water at 100°C is cooled to 25°C after three - stage exchange. Continuing the reverse continuous cycle of input and output, the exchange remains stable, and the heat exchange rate is 150%, and the heat exchange rate of each is 75%. The high - temperature input is converted into low - temperature output, and the low - temperature input is converted into high - temperature output. If more adiabatic heat - preservation heat exchanges are connected in series to form smaller and more stepped temperature differences, the effective heat exchange rate is infinitely close to 1, realizing temperature interchange. The exchange process is as Figure 9 shown Figure 9 a graph of sectional adiabatic conduction heat exchange.

[0065] The low heat exchange and regeneration efficiency described above are caused by the physical properties and structural forms of the material. The stepped counter - current sectional heat exchange device in this embodiment aims to change the heat exchange method and improve the efficiency. Through the design of adiabatic heat preservation, sectionalization, and efficient heat exchange process, it solves the problems of low temperature difference, close temperature, and low efficiency in the heat exchange area caused by the forward and backward longitudinal heat transfer of the heat exchange device. The main features are: the heat exchange pipeline adopts an S - shaped design, effectively increasing the lateral heat conductivity and reducing the longitudinal heat conductivity in the heat exchange area, so that the reverse fluid in the heat exchange area forms a gradient temperature difference from high to low; the liquid inside and outside the pipeline continuously impacts, squeezes, rubs, and turns over during the flow to improve the heat exchange speed; the heat exchange area works independently in sections, and the connecting pipelines between the heat exchange sections are connected by adiabatic or low - heat - conductivity connectors, and the connecting water tanks between the heat exchange sections adopt a design of reducing the liquid heat - conducting cross - sectional area to limit the flow, reducing the longitudinal heat transfer of heat energy through the pipeline material and the liquid at the same time, forming a stepped temperature difference between the heat exchange sections; the heat exchange water tank is equipped with a stable water - level limiting and heat - preservation and heat - insulation device, so that each heat exchange area does not interfere with each other and conducts independent heat exchange, maintaining the heat exchange efficiency and the instantaneous state of stabilizing the temperature of each section when the flow rate is unstable, and not transferring heat energy to each other to cause a decrease in temperature difference.

[0066] The schematic diagram of cascade temperature heat exchange is asFigure 5 , Figure 11 and Figure 12 as shown.

[0067] In this embodiment, a series-parallel segmented adiabatic cascade method is adopted to enable the remaining temperature difference fluid to continue to perform countercurrent heat exchange, further improving the heat exchange efficiency. The schematic diagram of the stepped countercurrent segmented heat exchange is as Figure 5 shown.

[0068] Referring to Figure 13 , according to theoretical analysis and calculation, when the heat exchange efficiency of the same mass of fluid through each heat exchange device is the same, through multi-stage series connection, the total heat exchange efficiency = (stage efficiency × number of stages) ÷ [stage efficiency × number of stages + loss efficiency (1 - stage efficiency)]. For example, when the heat exchange efficiency of each stage is 0.5 (i.e., the heat exchange efficiency = 100%), the total heat exchange efficiency of 10-stage series connection is approximately equal to 0.909 (i.e., the heat exchange efficiency is 181.8%). Ignoring the natural heat dissipation loss, it is equivalent to saving 90.9% of the heating power. The principle is shown in the figure: Taking the 3-stage series heat exchange as an example, in the initial state, the high-temperature fluid is 40°C and the low-temperature fluid is 10°C. They flow in opposite directions and meet in their respective tank pipes. After 100% heat exchange through the heat exchange section 2, at this time, the outlet temperatures of the high- and low-temperature fluids are the same at 25°C. The temperature drop of the high-temperature fluid outlet is 50% of the temperature difference between the two fluids, and the temperature rise of the low-temperature fluid outlet is 50% of the temperature difference between the two fluids. The counter-temperature difference fluids continue to enter their respective next stages for 100% heat exchange. The 25°C cold fluid enters and exchanges heat with the 40°C hot fluid, and the outlet temperature is 32.5°C. The 25°C hot fluid enters and exchanges heat with the 10°C cold fluid, and the outlet temperature is 17.5°C. At the same time, the fluids flow in opposite directions to continuously supplement heat energy to increase the temperature difference and exchange heat energy to reduce the temperature difference, gradually reaching a stable equilibrium state. After each stage of heat exchange of the counter-flowing fluids, the temperature difference gradually decreases. The cold fluid is raised to 32.5°C and the hot fluid is lowered to 17.5°C. Finally, the temperatures of the two outputs are interchanged, the high temperature is changed to low temperature, and the low temperature is changed to high temperature. The obtained heating and cooling efficiencies are both 0.75 (equivalent to a heat exchange efficiency of 150%). If an infinite cascade is added, the high-temperature fluid gradually cools down to close to the initial input temperature of the low-temperature fluid and is discharged, and the low-temperature fluid gradually warms up to close to the initial input temperature of the high-temperature fluid and enters the water storage tank to achieve the purpose of energy conservation and emission reduction.

[0069] According to the design embodiment of the stepped countercurrent segmented heat exchange device in this embodiment, the energy-saving heat exchange integrated shower water heater has remarkable energy-saving and emission-reduction effects. Due to the limitation of the test product size, the heat regeneration efficiency of the stepped countercurrent segmented heat exchange device is tested: when the water flow rate is 3 to 6 liters per minute, it is between 0.84 and 0.82, that is, the heat exchange efficiency is between 168% and 164%, which is equivalent to the energy efficiency ratio between 1:6.25 and 1:5.55; due to the integrated design, the installation and maintenance are simple, it can be disassembled and cleaned to maintain the heat exchange efficiency, and it can be continuously used infinitely after 20 minutes of water supply and power on; the water storage capacity is small, the instantaneous maximum heating power is low, and when used simultaneously, the impact on the power grid is small; there is no mechanical operation wear and noise, and the service life is long; the efficiency of the heat exchange device is stable, and the water temperature has no effect on the heat exchange efficiency; the small-volume heat preservation heating water storage tank has less heat dissipation loss, fast heating, and high heat preservation efficiency. The structure and principle are described as Figures 14 - 20 shown.

[0070] See Figure 15 , for the working process and principle: Taking the tap water temperature of 12°C and the semi-closed space of the shower room as an example, because the device is equipped with an approximately 24.3L vertical cuboid heat preservation heating water storage tank, the cold water inlet is located at the bottom, and the hot water outlet is located at the top. The heat conduction area in the 1.8-meter height direction is small, and about 22L of hot water with stable temperature can be continuously discharged. Using the 2.18KW electric heating method, after filling with water and power on for about 23.5 minutes, the water temperature rises by 30°C, and the power consumption is about 850.5W. The water temperature in the water storage tank is 42°C. At this time, the shower valve is opened. Since the heating control temperature measuring device is located near the cold water inlet of the heat preservation heating water storage tank, the cold water is immediately powered on for heating after entering and cooling, and at the same time, the hot water is about 39.5°C after absorbing heat and cooling through the 37°C surface of the human body. After a period of time, the surface temperature of the human body rises and the air humidity in the shower room reaches saturation, and the vaporization heat absorption cooling rate gradually decreases, and the energy loss of the hot water decreases. The hot water converges from the platform board into the stepped countercurrent segmented heat exchange device (such as Figure 16As shown in the figure, the total regenerative efficiency of the 8-stage design theory is 0.888. After actual measurement, it is about 0.84 - 0.82 when the water flow rate is 3L / min to 6L / min, and the regenerative efficiency of each stage is about 0.4. When the heat exchange water tank is filled with water (about 14L, and the time is about 2.33 minutes), it gradually enters the highest-efficiency heat exchange (calculated according to the average efficiency of 0.82). The tap water is heated to (39.5°C - 12°C) × 0.82 + 12°C = 34.55°C and enters the water storage tank. When continuously using 30L of water, the consumed heat energy is 30°C × 30Kg × 4.2KJ = 3780KJ, and the exchanged regenerative energy is 22.55°C × 30Kg × 4.2KJ = 2841.3KJ. When in use, the consumed electric energy for heat supplement is 3780KJ - 2841.3KJ = 938.7KJ, and the power consumption is 938.7KJ ÷ 3.6KJ.S = 260.75W. The electric heating time is about 7.18 minutes. The power consumption for the initial heating and temperature rise is 850.5W + heat supplement 260.75W = 1111.25W. If there is no regenerative heat exchange, the normal required power is: (24.3L of water in the water storage tank + 30L of used water) × temperature rise of 30°C × 4.2KJ ÷ 3.6KJ.s = 1900.5W. For the first use, the energy saving is 1900.5W - 1111.25W = 789.25W, and the energy saving efficiency is 789.25 ÷ 1900.5 = 0.415. After the water in the water storage tank is heated for the first time, when continuously using, for every 30L of water, the energy saving efficiency of regenerative heat exchange is 2841.3kJ ÷ 3780KJ = 0.7516, that is, the energy saving is 75.16%. After heat exchange, the hot waste water is cooled to 39.5°C - 22.55°C = 16.95°C, which is 4.95°C higher than the initial temperature of the tap water and is discharged into the environment, reducing the heat discharge by 75.16%.

[0071] According to the experimental test data, when the bathing flow rate is 6L / min and continuously using 30L of water for 5 minutes, it is necessary to simultaneously electrically heat for 7.18 minutes. When the bathing flow rate ≤ 5L / min and continuously using, when electrically heating simultaneously, the hot water temperature can be kept stable. In areas where the tap water temperature is lower than 12°C, just appropriately increase the heating control temperature (the highest design limit temperature of the equipment is 55°C to prevent high-temperature scalding and scale formation in the heat preservation heating box). Through the mixing valve and flow regulation, various bathing temperatures can be satisfied for use.

[0072] If the volume is increased to improve the regenerative efficiency of the stepped countercurrent segmented heat exchange device to 0.9, in summer when the tap water temperature ≥ 26°C and the bathing temperature is 35°C, the regenerative temperature is [((human body temperature 37°C + 35°C) ÷ 2 - 26°C)] × 0.9 + 26°C = 35°C, and the hot water output temperature = the entering temperature of the tap water after heat exchange. When continuously using until the human body cools down, there is no need to supplement energy to raise the tap water temperature by 9°C. Only by providing the initial temperature of the water storage tank for full-efficiency heat exchange can it be continuously used without energy consumption. This is an energy-saving effect that cannot be achieved by existing heating devices.

[0073] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A stepped countercurrent segmented heat exchange device, comprising a heat exchange body (1), characterized in that: The heat exchange body (1) comprises a heat exchange area (2) for supplying cold and hot fluid heat exchange; The heat exchange area (2) is provided with a plurality of sections, the plurality of heat exchange areas (2) are interconnected and arranged at independent intervals, each heat exchange area (2) is provided with a heat exchange pipe (3) connected to each other, and a gap for hot fluid flow is formed between the heat exchange area (2) and the heat exchange pipe (3); The heat exchange pipe (3) is provided with an insulating pipe (4) for preventing heat transfer between two adjacent heat exchange areas (2), so that the cold and hot fluids in each heat exchange area (2) do not interfere with each other and can exchange heat independently during the heat exchange process. Each heat exchange area (2) is separated by the insulating pipe (4) to form a step-type temperature difference between each heat exchange area (2).

2. The stepped countercurrent segmented heat exchange device according to claim 1, characterized in that: The heat-insulating pipe (4) is arranged at a connection point between two adjacent heat exchange areas (2).

3. The stepped countercurrent segmented heat exchange device according to claim 1, characterized in that: The hot fluid flows in a forward direction along each heat exchange zone (2) in sequence, and the cold fluid flows in a reverse direction relative to the hot fluid in the heat exchange pipe (3), so that a stepped countercurrent segmented heat exchange is formed between the cold and hot fluids in each heat exchange zone (2).

4. The stepped countercurrent segmented heat exchange device according to claim 3, characterized in that: A transverse heat exchange zone (5) and a longitudinal heat exchange zone (6) are provided between each heat exchange zone (2) and the heat exchange pipe (3), and the heat exchange pipe (3) is arranged in a circuitous manner on each heat exchange zone (2) to effectively increase the transverse thermal conductivity of the transverse heat exchange zone (5) in each heat exchange zone (2) and relatively reduce the longitudinal thermal conductivity of the longitudinal heat exchange zone (6) in each heat exchange zone (2), so that the reverse fluid in each heat exchange zone (2) forms a gradient temperature difference from high to low.

5. The stepped countercurrent sectional heat exchange device according to claim 1, characterized in that: The heat exchange pipes (3) between the two adjacent heat exchange areas (2) are connected by using a heat-insulating pipe (4) made of a heat-insulating material or a low-thermal-conductivity material.

6. The stepped countercurrent segmented heat exchange device according to claim 1, characterized in that: The heat exchange body (1) is provided with a plurality of partitions (7), one end of the partition (7) is connected to the inner side of the heat exchange body (1), and a flow limiting notch (8) is provided between the other end of the partition (7) and the heat exchange body (1), so that the heat exchange body (1) is divided into a plurality of heat exchange areas (2) which are interconnected and arranged independently of each other through the plurality of partitions (7).

7. The stepped countercurrent sectional heat exchange device according to claim 6, characterized in that: A water trough-shaped heat exchange area (2) is formed between the inner side of the heat exchange body (1) and the partition (7), and a flow-limiting notch (8) adjacent to the connection between the two heat exchange areas (2) forms a cross-section-reducing flow-limiting and heat-insulating design. The flow-limiting notch (8) forms a small-area transition area for the hot fluid to enter another heat exchange area (2) from one heat exchange area (2). The flow-limiting notch (8) is used to maintain the temperature difference between the various heat exchange areas (2) during the transition connection, and is used to maintain the stepped temperature difference between the various heat exchange areas (2).

8. The stepped countercurrent sectional heat exchange device according to claim 6, characterized in that: The heat exchange body (1) is provided with a stable water level flow limiting device (9), which comprises a water retaining ring (10) extending upwardly from the heat exchange body (1) and forming a barrier to slow down the discharge flow speed of the hot fluid, a drainage channel (11) for discharging waste water is provided in the water retaining ring (10), the drainage channel (11) passes through the water retaining ring (10) from top to bottom, and a drainage port (12) is provided on one side of the upper part of the water retaining ring (10).

9. The stepped countercurrent sectional heat exchange device according to claim 6, characterized in that: The heat exchange body (1) comprises a seat (13) and a cover (14) covering the seat (13); the partition (7) and the seat (13) are respectively sealed with the cover (14) via a sealing member, so that two adjacent heat exchange areas (2) are connected to each other only via a flow limiting notch (8); A heat-insulating layer is provided on the periphery of the seat body (13) and the partition (7), and the heat-insulating layer and the heat-insulating pipe (4) form a heat-insulating device for the heat exchange body (1), so that each heat exchange area (2) does not interfere with each other and exchanges heat independently, and maintains the heat exchange efficiency and stabilizes the instantaneous state of the temperature of each heat exchange area (2) when the flow rate of the hot fluid is unstable, and the phenomenon of mutual transfer of heat energy between each heat exchange area (2) causing a decrease in temperature difference will not occur; The cover body (14) is provided with a water inlet (15) for guiding hot fluid into the heat exchange area (2).

10. A water heater, comprising a water heater body (16), characterized in that: The water heater body (16) is provided with a stepped countercurrent segmented heat exchange device according to any one of claims 1 to 9, and the heat exchange body (1) is arranged at the lower part of the water heater body (16) and is used to collect the hot fluid output by the water heater body (16).

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