A stepped counterflow sectional heat exchange device and a water heater thereof

Abstract

The utility model relates to the technical field of heat exchanger, propose a kind of stepped countercurrent subsection heat exchange device and the application of water heater thereof, stepped countercurrent subsection heat exchange device, including heat exchange main part, the heat exchange main part includes heat exchange area and heat exchange pipeline;Heat exchange area is equipped with several sections, several heat exchange areas are communicated with each other and mutually independent interval arrangement, and heat exchange pipeline connected with each other is equipped in each heat exchange area;Heat exchange pipeline is equipped with the heat insulation pipe for preventing the heat transfer between adjacent two heat exchange areas, to make the cold, hot fluid of each heat exchange area realize mutual non-interference in heat exchange process, and independent heat exchange, and each heat exchange area is formed heat transfer separation by heat insulation pipe, and the stepped temperature difference is formed between each heat exchange area.The subsection design of heat exchange area avoids the overall temperature difference homogenization problem caused by heat diffusion of traditional device, and heat exchange pipeline completes efficient heat exchange independently in each heat exchange area, improves overall heat exchange efficiency.

Description

Technical Field

[0001] This utility model relates to the technical field of heat exchangers, specifically to a stepped counter-current segmented heat exchange device and its water heater; by changing the design of the flow channel or pipe for cold and hot fluids, it can also be used in the heat exchange field of various fluids or gases. Background Technology

[0002] Modern water heaters are among the most energy-intensive household appliances, typically ranging from 2.5KW to 8.5KW and above. Assuming each person showers for 5 minutes, using 30 liters of water at an average temperature of 30℃, the energy consumption is calculated as follows: (Specific heat capacity of water 4200J / (kg·℃) × mass 30kg × temperature 30K ÷ 3600s = 1050W). Instantaneous water heaters require a power output of 12.6KW, while storage-type heaters require preheating and insulation, resulting in even greater heat loss. Furthermore, these heaters place a heavy load on the power grid, with both households and power plants emitting heat and polluting the environment.

[0003] Existing air source heat pump water heaters have reduced energy efficiency in environments requiring heating, especially in cold weather, and require about 3KW of electric auxiliary heating. Because they generally use outdoor water storage tanks and water supply pipes of more than 100 liters, the temperature difference is large and the temperature drops quickly, requiring intermittent operation 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 are slow to take effect because the heat recovery from heat exchange is slower than the heat output. The time required for water to exchange heat through the metal pipe medium is calculated as: water heat capacity × mass × temperature ÷ heat transfer power (temperature difference × thermal conductivity × heat transfer area ÷ heat transfer distance × metal heat transfer efficiency). Hot water must be preheated to meet the instantaneous heat output requirement, making it impossible to reduce the heating power of the water heater. If a shower lasts about 5 minutes with 30 liters of water, the water may stop being used before reaching the designed heat exchange efficiency. The heat energy of the wastewater will not be utilized and must be discharged. Keeping it will also cause heat loss and poor energy-saving effect. Even with an infinitely long heat exchange zone, the heat exchange efficiency is 100% (but the material also consumes heat energy, making it impossible to achieve), meaning the output energy equals the input energy. With a 30°C temperature difference, for the same mass of water, cold water heats up by 15°C while hot water cools down by 15°C. The actual heat recovery efficiency is ≤0.5 (because of heat loss during prolonged immersion, it is not as efficient as direct mixing due to shorter time).

[0005] like Figure 1 Straight or ring-shaped heat exchange devices have slow heat exchange rates. To improve efficiency, the exchange zone must be lengthened, resulting in a larger volume and greater heat loss. Figure 2 Parallel pipe heat exchange devices use a lot of metal materials, which conduct heat quickly, making it difficult to create a temperature difference between the inlet and outlet water ends, resulting in low efficiency. Figure 3 Plate heat exchangers have a large surface area, requiring increased material strength to withstand water pressure, making them difficult to clean and maintain, and their efficiency gradually decreases. Figure 4Due to manufacturing limitations, spiral pipe heat exchange devices have large bending diameters, large outer groove volumes, long water-heat exchange times with the center, low efficiency, and are difficult to clean and maintain.

[0006] Existing countercurrent heat exchange devices suffer from the following problem: the liquids flow longitudinally in opposite directions within the exchange zone, and the liquid flow, liquid heat conduction, and heat conduction of the heat exchange pipes are all in opposite directions within the longitudinal direction of the exchange zone. The high and low temperature fluids pass through the exchange zone and exit within a few seconds. Due to the short time, 100% heat exchange cannot be achieved, and the outlet temperature of the high temperature fluid is higher than that of the low temperature fluid. With a longer time, the temperature in the exchange zone becomes uniform, achieving 100% heat exchange, and the outlet temperatures of the high and low temperature fluids become uniform, meaning that each receives 50% of the temperature difference for heating and cooling. Therefore, the heat recovery rate cannot exceed 0.5.

[0007] If the exchange zone is extended to an infinite length and the flow rate is stabilized to a suitable speed, and low thermal conductivity materials are used for the heat exchange pipes and exchange water tank, the outlet temperature of the low-temperature fluid can be higher than that of the high-temperature fluid. However, the heat exchange power is low, the volume is large, and the heat recovery is small, making it impractical. When the flow rate is unstable, 100% heat exchange cannot be achieved, and the stable heat recovery rate of 0.5 cannot be broken. Utility Model Content

[0008] This invention proposes a stepped counter-current segmented heat exchange device and its water heater. The stepped counter-current segmented heat exchange device consists of several interconnected but independently spaced heat exchange zones within the main heat exchange body. Each heat exchange zone is equipped with heat exchange pipes, and adjacent heat exchange zones are separated by insulating pipes, ensuring that each heat exchange zone forms an independent temperature zone, thus establishing a stepped temperature difference. The segmented design of the heat exchange zones avoids the problem of overall temperature uniformity caused by heat diffusion in traditional devices. Cold and hot fluids independently complete efficient heat exchange within each heat exchange zone, with each zone not interfering with the others, significantly improving the overall heat exchange efficiency.

[0009] A stepped counter-current segmented heat exchange device designed for this purpose includes a heat exchange body, which includes a heat exchange zone for cooling and hot fluid heat exchange.

[0010] The heat exchange zone is provided in several sections. The heat exchange zones are interconnected and set at independent intervals. Each heat exchange zone is provided with heat exchange pipes that are connected to each other. A cold fluid flow gap is formed between the heat exchange zone and the heat exchange pipes.

[0011] The heat exchange pipe is equipped with an insulating pipe to prevent heat transfer between two adjacent heat exchange zones, so that the cold and hot fluids in each heat exchange zone can achieve independent heat exchange without interference during the heat exchange process, and each heat exchange zone is separated by an insulating pipe to form a heat transfer separation, and a stepped temperature difference is formed between each heat exchange zone.

[0012] The insulation pipe is installed at the connection point between two adjacent heat exchange zones.

[0013] The hot fluid flows sequentially in the forward direction along each heat exchange zone, while the cold fluid flows in the opposite direction to the hot fluid in the heat exchange pipe, so that the cold and hot fluids form a stepped counter-current segmented heat exchange in each heat exchange zone.

[0014] Each heat exchange zone is connected to a transverse heat exchange zone and a longitudinal heat exchange zone. The heat exchange zone is arranged in a meandering manner on each heat exchange zone to effectively increase the transverse thermal conductivity of the transverse heat exchange zone in each heat exchange zone and relatively reduce the longitudinal thermal conductivity of the longitudinal heat exchange zone in each heat exchange zone, so that the reverse fluid in each heat exchange zone forms a gradient temperature difference from high to low.

[0015] The heat exchange pipes between the two adjacent heat exchange zones are connected by insulated pipes made of insulating material or low thermal conductivity material.

[0016] The heat exchange body is provided with several partitions. One end of the partition is connected to the inside of the heat exchange body, and the other end of the partition is provided with a flow-limiting gap between it and the heat exchange body, so that the heat exchange body is divided into several interconnected and independently spaced heat exchange zones by the partitions.

[0017] The heat exchange body forms a water tank-shaped heat exchange zone between its inner side and the partition. The flow-limiting gap at the connection between two adjacent heat exchange zones forms a reduced cross-section flow-limiting and heat-insulating design. The flow-limiting gap forms a small transition zone for hot fluid to enter another heat exchange zone. The flow-limiting gap is used to maintain the temperature difference when the heat exchange zones are connected, and to maintain the stepped temperature difference between the heat exchange zones.

[0018] The heat exchange body is equipped with a water level stabilizing and flow limiting device. The water level stabilizing and flow limiting device includes a water baffle ring that extends upward along the heat exchange body and forms a water baffle ring to block and slow down the flow rate of the hot fluid. The water baffle ring is equipped with a drainage channel for discharging wastewater. The drainage channel runs through the water baffle ring from top to bottom. A drain outlet is provided on one side of the upper part of the water baffle ring.

[0019] The heat exchange body includes a base and a cover that is fitted onto the base. The partition and the base and the cover are respectively sealed together by a sealing element so that two adjacent heat exchange zones are connected to each other only through a flow-limiting gap.

[0020] The seat body and partition are provided with a heat insulation layer. The heat insulation layer and the heat insulation pipe form a heat insulation device for heat exchange, so that each heat exchange zone does not interfere with each other and exchanges heat independently. When the flow rate of the hot fluid is unstable, the heat exchange efficiency and the instantaneous temperature of each heat exchange zone are stable. There is no phenomenon of heat energy transfer between each heat exchange zone causing a decrease in temperature difference.

[0021] The cover is provided with an inlet for guiding hot fluid into the heat exchange zone.

[0022] A water heater designed for this purpose includes a water heater body, on which the aforementioned stepped counter-current segmented heat exchange device is provided. The heat exchange body is located at the lower part of the water heater body and is used to collect the hot fluid output by the water heater body.

[0023] The beneficial technical effects of this utility model are as follows:

[0024] The stepped counter-current segmented heat exchanger consists of several interconnected yet independently spaced heat exchange zones within the main heat exchange unit. Each zone is equipped with heat exchange pipes, and adjacent zones are separated by insulating pipes to ensure independent temperature zones within each zone, thus creating a stepped temperature difference. This segmented design avoids the problem of uniform temperature distribution caused by heat diffusion in traditional devices. Cold and hot fluids independently complete efficient heat exchange within each zone, with no interference between zones, significantly improving overall heat exchange efficiency. Attached Figure Description

[0025] Figure 1 This refers to existing straight or annular pipe heat exchange devices.

[0026] Figure 2 This is a parallel pipeline heat exchange device based on existing technology.

[0027] Figure 3 This refers to a plate heat exchange device based on existing technology.

[0028] Figure 4 This is a spiral pipe heat exchange device based on existing technology.

[0029] Figure 5 This is a schematic diagram of the planar structure of a stepped countercurrent segmented heat exchange device according to an embodiment of the present invention.

[0030] Figure 6 This is a schematic diagram of the tortuous arrangement of heat exchange pipes according to an embodiment of the present invention.

[0031] Figure 7 This is a three-dimensional structural diagram of a water level stabilizing flow limiting device according to an embodiment of the present invention.

[0032] Figure 8 This is a schematic diagram of the structure of the cover body according to an embodiment of the present invention.

[0033] Figure 9 This is a diagram showing the segmented adiabatic conduction heat exchange curves of a stepped countercurrent segmented heat exchange device according to an embodiment of this utility model.

[0034] Figure 10 This is an embodiment of the present invention that conforms to the law of conservation of energy, representing an ideal heat exchange state.

[0035] Figure 11 This is a schematic diagram of the cold and hot fluid heat exchange structure of a stepped countercurrent segmented heat exchange device according to an embodiment of the present invention.

[0036] Figure 12 This is a schematic diagram of the heat exchange structure of the cold and hot fluids in another direction of a stepped countercurrent segmented heat exchange device according to an embodiment of the present invention.

[0037] Figure 13 This is a schematic diagram of the heat exchange curve structure of the cold and hot fluids in a stepped countercurrent segmented heat exchange device according to an embodiment of this utility model.

[0038] Figure 14 This is a three-dimensional structural diagram of a stepped counter-current segmented heat exchange device applied to a water heater according to an embodiment of the present invention.

[0039] Figure 15 This is a schematic diagram of the planar structure of a stepped counter-current segmented heat exchange device applied to a water heater according to an embodiment of the present invention.

[0040] Figure 16 This is a three-dimensional structural diagram of a stepped counter-current segmented heat exchange device applied to a water heater according to an embodiment of the present invention, and a structural diagram showing the cover and the base separated.

[0041] Figure 17 This is a heat exchange curve of a first liquid and a second liquid with the same flow rate in opposite directions in a liquid heat exchanger when they conduct heat to each other until there is no temperature difference, according to an embodiment of this utility model.

[0042] Figure 18 This is a graph showing the initial use or reuse after a long period of inactivity of an embodiment of the present invention, when the first liquid fills the first heat exchange zone.

[0043] Figure 19 This is a graph showing the first liquid filling each heat exchange zone according to an embodiment of the present invention.

[0044] Figure 20 This is a graph showing the liquid heat exchange device of a water heater according to an embodiment of the present invention after continuous and stable use and then when it is no longer in use. Detailed Implementation

[0045] The technical solutions of the present utility model will be clearly and completely described below with reference to the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. In order to make the above-mentioned objects, features and advantages of the present application more apparent and understandable, many specific details are set forth in the following description in order to provide a full 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 spirit of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0046] See Figures 5-20 A stepped counter-current segmented heat exchange device includes a heat exchange body 1, wherein the heat exchange body 1 includes a heat exchange zone 2 for cooling and hot fluid heat exchange;

[0047] The heat exchange zone 2 is provided in several sections. The heat exchange zone 2 sections are interconnected and arranged independently at intervals. Each heat exchange zone 2 section is provided with heat exchange pipes 3 that are connected to each other. A hot fluid flow gap is formed between the heat exchange zone 2 and the heat exchange pipes 3.

[0048] The heat exchange pipe 3 is equipped with an insulating pipe 4 to prevent heat transfer between two adjacent heat exchange zones 2, so that the cold and hot fluids in each heat exchange zone 2 can achieve independent heat exchange without interference during the heat exchange process, and each heat exchange zone 2 is separated by the insulating pipe 4 to form a heat transfer separation, and a stepped temperature difference is formed between each heat exchange zone 2.

[0049] The stepped counter-current segmented heat exchange device consists of several interconnected but independently spaced heat exchange zones 2 within the heat exchange body 1. Each heat exchange zone 2 is equipped with a heat exchange pipe 3, and adjacent heat exchange zones 2 are separated by insulating pipes 4 to ensure that each heat exchange zone 2 forms an independent temperature zone, thus establishing a stepped temperature difference. The segmented design of the heat exchange zones 2 avoids the problem of overall temperature difference homogenization caused by heat diffusion in traditional devices. Cold and hot fluids independently complete efficient heat exchange within each heat exchange zone 2, and each heat exchange zone 2 does not interfere with the others, significantly improving the overall heat exchange efficiency.

[0050] The insulating pipe 4 effectively prevents heat transfer between adjacent heat exchange zones 2, ensuring that the cold and hot fluids in each heat exchange zone 2 complete efficient heat exchange in an independent space. This segmented design allows each heat exchange zone 2 to form an independent temperature gradient, creating a stepped temperature difference overall, thereby significantly improving heat exchange efficiency, making the heat exchange process more stable and controllable, and ensuring that the temperature state of each heat exchange zone 2 is not disturbed.

[0051] The insulation pipe 4 is installed at the connection between two adjacent heat exchange zones 2.

[0052] By placing the insulating pipe 4 at the connection point of adjacent heat exchange zones 2, heat transfer through the connecting area can be precisely blocked. This layout ensures that when cold and hot fluids exchange heat in different heat exchange zones 2, the heat conduction paths between each segment are physically isolated, thereby maintaining an independent temperature difference in each heat exchange zone 2. The placement design of the insulating pipe 4 balances the continuity of fluid flow with the effectiveness of heat blocking, avoiding the problem of overall temperature difference convergence caused by heat conduction in the connecting area in traditional structures, and further strengthening the design goal of stepped temperature difference.

[0053] The hot fluid flows sequentially in the forward direction along each heat exchange zone 2, while the cold fluid flows in the opposite direction to the hot fluid in the heat exchange pipe 3, so that the cold and hot fluids form a stepped counter-current segmented heat exchange in each heat exchange zone 2.

[0054] By employing a counter-current design where the hot fluid flows forward and the cold fluid flows in the opposite direction within the heat exchange pipe 3, the hot and cold fluids achieve maximum temperature difference contact within each heat exchange zone 2, significantly improving heat exchange efficiency. The counter-current flow pattern enables efficient heat exchange between the high-temperature hot fluid and the low-temperature cold fluid in each heat exchange zone 2. A temperature gradient gradually forms as the flow progresses, and the segmented design further decomposes the overall temperature difference into multiple stepped temperature differences. This synergistic effect not only extends the effective heat exchange time but also ensures stable temperature differences in each heat exchange zone 2 through staged heat exchange.

[0055] Each heat exchange zone 2 is provided with a transverse heat exchange zone 5 and a longitudinal heat exchange zone 6 between it 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 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.

[0056] The division into transverse heat exchange zone 5 and longitudinal heat exchange zone 6, combined with the meandering arrangement of heat exchange pipes 3, significantly increases the transverse heat conduction area while reducing the longitudinal thermal conductivity by shortening the longitudinal flow path length. This design allows for full contact between cold and hot fluids in the transverse heat exchange zone 5, with heat being transferred rapidly laterally. In contrast, the long distance of the metal pipes in the longitudinal heat exchange zone 6 results in slower heat conduction, maintaining a large, stepped temperature difference and reducing heat transfer. Consequently, a gradient temperature difference from high to low is formed within each section of the heat exchange zone 2, effectively preventing temperature homogenization. Furthermore, the meandering pipes enhance fluid turbulence, further improving heat exchange efficiency.

[0057] The heat exchange pipes 3 between the two adjacent heat exchange zones 2 are connected by insulated pipes 4 made of insulating material or low thermal conductivity material.

[0058] By using insulating materials or materials with low thermal conductivity to construct the insulating pipes 4 between adjacent heat exchange zones 2, the longitudinal transfer of heat through the pipe wall can be blocked at the material level. This design not only reduces heat loss but also ensures that the temperature difference of each heat exchange zone 2 is independently controllable. The synergistic effect of the material selection and structural design of the insulating pipes 4 solves the problem of segmented temperature difference failure caused by the heat conduction of traditional metal pipes, enabling the stepped temperature difference to be maintained for a long time, which is especially suitable for high-temperature or large-temperature-difference applications.

[0059] The heat exchange body 1 is provided with several partitions 7. One end of the partition 7 is connected to the inside of the heat exchange body 1, and the other end of the partition 7 is provided with a flow-limiting gap 8 between it and the heat exchange body 1, so that the heat exchange body 1 is divided into several interconnected and independently spaced heat exchange zones 2 by the partitions 7.

[0060] The heat exchange body 1 forms a water tank-shaped heat exchange zone 2 between its inner side and the partition 7. The flow-limiting gap 8 at the connection between two adjacent heat exchange zones 2 forms a reduced cross-section flow-limiting and heat-insulating design. The flow-limiting gap 8 forms a small transition area for hot fluid to enter another heat exchange zone 2 from the heat exchange zone 2. The flow-limiting gap 8 is used to maintain the temperature difference when the heat exchange zones 2 are connected, and to maintain the stepped temperature difference between the heat exchange zones 2.

[0061] The baffle 7 divides the heat exchange body 1 into multiple independent heat exchange zones 2. The design of the flow-limiting notch 8 ensures continuous fluid flow while restricting the liquid flow cross-sectional area of ​​adjacent areas. The physical isolation effect of the baffle 7 effectively reduces direct heat conduction between heat exchange zones 2, while the small cross-sectional design of the flow-limiting notch 8 reduces the longitudinal transfer of heat through the liquid itself by limiting the fluid flow cross-sectional area. This structure maintains the connectivity of the overall flow channel while achieving physical isolation of segmented temperature differences, ensuring the independent operation of each heat exchange zone 2.

[0062] The reduced cross-section flow-limiting insulation design formed by the water-trough-shaped heat exchange zone 2 and the flow-limiting gap 8 increases the flow velocity and reduces the transition heat exchange rate between adjacent heat exchange zones 2 by limiting the flow area of ​​the fluid transition region. The flow-limiting gap 8, as a small-area transition zone, allows the fluid to flow along a predetermined path while reducing longitudinal heat transfer with the fluid migration through flow velocity control. This design ensures continuous system operation while maximizing the maintenance of temperature differences between the various sections of the heat exchange zone 2.

[0063] The heat exchange body 1 is provided with a stable water level flow limiting device 9. The stable water level flow limiting device 9 includes a water baffle ring 10 that extends upward along the heat exchange body 1 and forms a water baffle ring to block and slow down the flow rate of hot fluid discharge. The water baffle ring 10 is provided with a drainage channel 11 for discharging wastewater. The drainage channel 11 passes through the water baffle ring 10 vertically. A drain outlet 12 is provided on one side of the upper part of the water baffle ring 10.

[0064] The stabilizing water level flow limiting device 9 slows down the discharge rate of hot fluid through the water-blocking ring 10, ensuring a stable water level within the heat exchange zone 2. The coordinated design of the drainage channel 11 and the drain outlet 12 precisely controls the fluid discharge rate, preventing temperature fluctuations caused by sudden changes in flow rate. This structure can maintain water level balance in each section of the heat exchange zone 2 even when the fluid flow rate is unstable, avoiding a decrease in heat exchange efficiency caused by water level changes, while further consolidating the stepped temperature difference through the flow limiting effect.

[0065] The heat exchange body 1 includes a base 13 and a cover 14 covering the base 13. The partition 7 is sealed to the base 13 and the cover 14 by a sealing element, so that the two adjacent heat exchange zones 2 are connected to each other only through the flow-limiting gap 8.

[0066] The seat 13 is provided with a heat insulation layer on its periphery and the partition 7. The heat insulation layer and the heat insulation pipe 4 form a heat insulation device for the heat exchange body 1, so that each heat exchange zone 2 does not interfere with each other and exchanges heat independently. When the flow rate of the hot fluid is unstable, the heat exchange efficiency is maintained and the instantaneous temperature of each heat exchange zone 2 is stabilized. There will be no phenomenon of heat energy transfer between each heat exchange zone 2 causing a decrease in temperature difference.

[0067] The cover 14 is provided with an inlet 15 for guiding hot fluid into the heat exchange zone 2.

[0068] The sealing fit between the seat 13 and the cover 14, along with the thermal insulation layer design, structurally blocks external environmental thermal interference while ensuring that adjacent heat exchange zones 2 are connected only through the flow-limiting gap 8. The combination of the seal and the partition 7 completely eliminates the risk of fluid cross-flow and leakage, and the thermal insulation layer, together with the insulation pipe 4, forms multiple thermal barriers. This design maintains the instantaneous temperature stability of each section even when the hot fluid flow rate fluctuates, eliminating temperature loss due to structural heat conduction or environmental heat dissipation.

[0069] A water heater includes a water heater body 16, on which the aforementioned stepped counter-current segmented heat exchange device is provided. The heat exchange body 1 is disposed 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.

[0070] The stepped counter-current segmented heat exchange device is integrated into the lower part of the water heater body 16, which can efficiently recover and utilize the high-temperature waste heat discharged by 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 water discharged by the water heater before entering the heating device for heating, reducing heating time and improving energy efficiency.

[0071] Using hot water [specific heat capacity 4200 J / (kg.℃), thermal conductivity 0.59 W / (mK)] at 40℃ and cold water at 10℃, with a consistent flow rate of 6 L / min, and the exchange pipes made of copper [specific heat capacity 390 J / (kg.℃), thermal conductivity approximately 400 W / (mK)] or stainless steel [specific heat capacity 500 J / (kg.℃), thermal conductivity approximately 16 W / (mK)], with an outer diameter of 20 mm and an inner diameter of 18 mm, experimental tests showed that, taking a traditional counter-current heat exchange device as an example, the heat exchange time to 100% for the counter-current water flow through a straight or large-arc smooth pipe and a low-flow-rate immersion tank exceeded 60 seconds. For the counter-current water flow using a stirring-forward method, the heat exchange time to 100% exceeded 7 seconds, depending on the intensity of the stirring. Because the cross-sectional area of ​​the pipe is the same as its perimeter, and its thermal conductivity is the same both longitudinally and laterally, there is currently no suitable material that has only high thermal conductivity laterally and low or no thermal conductivity longitudinally. Water's heat capacity is approximately 10 times higher than that of steel or copper (4200J ÷ 500J or 390J), meaning that heating and cooling water takes about 10 times longer than heating or cooling steel or copper. Furthermore, steel or copper has a much higher thermal conductivity than water. Therefore, for the water to be transferred laterally to a distance of 9mm between the pipe's center and outer diameter, the copper pipe has already transferred heat longitudinally to (400W / 0.59W * 18mm) = 1. For the same amount of heat at a distance of 2203mm, water also transfers heat in all directions with the same thermal conductivity during heat exchange. The heat transferred by the longitudinally opposing fluid flow is always much greater than the heat transferred by the transverse heat exchange. The heat energy is rapidly diffused and transferred to the large temperature difference zone, causing the temperature in the heat exchange zone to be close to uniform (6L×40℃+6L×10℃)÷(6L+6L)=25℃. When the heat exchange between the high and low temperature water reaches 25℃ with no temperature difference, the energy exchange stops, and no more heat energy is output or absorbed. It is impossible to break through 100% (i.e., 50% of the total temperature difference is heated and cooled) physical heat exchange efficiency. Furthermore, the aforementioned heat exchange zones are designed to be smooth and flat, with stable water flow and no impact or turbulence. This results in a slow heat exchange rate. When the pipe is full, and 100% heat exchange continues until there is no temperature difference between the inside and outside of the pipe, the outlet water temperature is very close to 25°C. The heat recovery efficiency = temperature rise (25°C - cold water 10°C) / temperature difference (hot water 40°C - cold water 10°C) = 0.5. At higher flow rates, the heat exchange time is insufficient, leading to even lower efficiency. It cannot exceed 50% of the temperature difference for heat exchange efficiency, thus failing to achieve true temperature exchange and failing to approach the ideal heat exchange state that conforms to the law of conservation of energy. Figure 10 As shown.

[0072] When two liquids of equal mass with different temperatures are directly mixed for 100% heat exchange, only 50% heat exchange efficiency can be achieved for each. This means the heat exchange from 100℃ to 50℃ is converted, and vice versa, resulting in an efficiency of 0.5, which is unrealistic. Figure 10 The effect shown is as follows. For example, two cups of water of equal mass with a temperature difference of 100°C (the hot one at 100°C and the cold one at 0°C), when poured together, exchange 100% heat and get two cups of water at 50°C, each with a 50% increase in temperature and a 50% decrease in temperature.

[0073] If a stepped temperature difference is used to divide the total temperature difference into three segments for heat exchange, and three cups are arranged in the order of high temperature → empty middle cup → low temperature, the exchange process will not cause heat conduction interference or heat loss. The exchange is done segment by segment. First, 0.5 cups of water from the high and low temperature cups are poured into the empty middle cup for 100% heat exchange (100℃ + 0℃) ÷ 2 = 50℃. This process is equivalent to the water flowing from high temperature to low temperature and vice versa, in opposite directions. The middle cup contains 1 cup of water at 50℃. Then, 0.5 cups of water are poured into both the high and low temperature cups for 100% heat exchange. After the exchange, the high temperature cup (100℃ + 50℃) ÷ 2 = 75℃ and the low temperature cup (50℃ + 0℃) ÷ 2 = 25℃ will each have 0.5 cups of water poured into the middle cup (75℃ + 0℃). (25℃) ÷ 2 = 50℃. The process is also reversible. At this point, the water in the low-temperature cup is 25℃ → the water in the middle cup is 50℃ → the water in the high-temperature cup is 75℃. That is, the water at 0℃ rises to 75℃ after three stages of exchange. The water in the high-temperature cup is 100℃ → the water in the middle cup is 50℃ → the water in the low-temperature cup cools down to 25℃. That is, the water at 100℃ cools down to 25℃ after three stages of exchange. This reverse cycle of input and output continues, and the exchange remains stable, with a heat exchange rate of 150%. Each has a heat exchange rate of 75%. The high-temperature input is replaced by the low-temperature output, and the low-temperature input is replaced by the high-temperature output. If more insulated heat exchangers are connected in series, smaller and more stepped temperature differences can be formed, and the effective heat exchange rate can approach 1, achieving temperature exchange. The exchange process is as follows: Figure 9 As shown, Figure 9 This is a segmented adiabatic conduction heat exchange curve.

[0074] The low heat exchange and regeneration efficiency mentioned above is caused by the physical properties and structural design of the materials. This embodiment of the stepped counter-current segmented heat exchange device aims to change the heat exchange method and improve efficiency. Through insulation, segmentation, and efficient heat exchange process design, it solves the problems of low temperature difference, near-uniform temperature, and low efficiency caused by the forward and backward longitudinal heat transfer in the heat exchange device. Its main features are: the heat exchange pipe adopts an S-shaped design, effectively increasing the lateral thermal conductivity and reducing the longitudinal thermal conductivity in the heat exchange zone, creating a gradient temperature difference from high to low for the counter-current fluid within the heat exchange zone; the liquids inside and outside the pipe flow continuously... The heat exchange rate is increased by continuous impact, extrusion, friction, and repositioning. The heat exchange sections work independently in segments. The connecting pipes between the heat exchange sections are connected by insulated or low thermal conductivity connectors. The water tanks connecting the heat exchange sections adopt a flow-limiting design that reduces the thermal conductivity of the liquid, thereby reducing the simultaneous longitudinal transfer of heat energy through the pipe material and the liquid, forming a stepped temperature difference between the heat exchange sections. The heat exchange water tank is equipped with a stable water level flow-limiting and heat insulation device, so that each heat exchange zone does not interfere with each other and can exchange heat independently. When the flow rate is unstable, the heat exchange efficiency and the instantaneous temperature of each section are stabilized, and heat energy is not transferred between them, which would cause the temperature difference to decrease.

[0075] A schematic diagram of stepped temperature heat exchange is shown below. Figure 5 , Figure 11 and Figure 12 As shown.

[0076] This embodiment employs a series segmented adiabatic cascade method to allow the remaining temperature difference fluid to continue counter-current heat exchange, further improving heat exchange efficiency. The schematic diagram of the stepped counter-current segmented heat exchange principle is shown below. Figure 5 As shown.

[0077] See Figure 13 According to theoretical analysis and calculation, when the heat exchange efficiency of the same mass of fluid is consistent in each heat exchange device, the total heat exchange efficiency is calculated as follows: (segment efficiency × number of segments) ÷ [segment efficiency × number of segments + loss efficiency (1 - segment efficiency)]. If the heat exchange efficiency of each segment is 0.5 (i.e., heat exchange efficiency = 100%), the total heat exchange efficiency of 10 segments in series is approximately 0.909 (i.e., heat exchange efficiency 181.8%). Ignoring natural heat loss, this is equivalent to saving 90.9% of heating power. The principle is shown in the figure: Taking a three-stage series heat exchanger as an example, initially, a high-temperature fluid of 40°C and a low-temperature fluid of 10°C meet in opposite directions in their respective heat exchange tubes. After 100% heat exchange in heat exchange section 2, the outlet temperatures of the high and low-temperature fluids are the same at 25°C. The temperature drop of the high-temperature fluid at the outlet is 50% of the temperature difference between the two fluids, and the temperature rise of the low-temperature fluid at the outlet is 50% of the temperature difference between the two fluids. The fluids with the opposite temperature difference continue to enter their respective next sections for 100% heat exchange. After the 25°C cold fluid exchanges heat with the 40°C hot fluid, its outlet temperature is 32.5°C. After the 25°C hot fluid exchanges heat with the 10°C cold fluid, its outlet temperature is 17.5°C. Simultaneously, the reverse flow of fluids continues to replenish heat energy, increasing the temperature difference, and exchanging heat energy to decrease the temperature difference, gradually reaching a stable equilibrium state. After each stage of heat exchange, the temperature difference of the reverse fluid gradually decreases, with the cold fluid increasing in temperature to 32.5℃ and the hot fluid decreasing in temperature to 17.5℃, ultimately resulting in the exchange of their output temperatures, with the high temperature becoming the low temperature and the low temperature becoming the high temperature. The resulting heating and cooling efficiencies are both 0.75 (equivalent to a heat exchange efficiency of 150%). If an infinite series is added, the high-temperature fluid gradually cools down to near the initial input temperature of the low-temperature fluid before being discharged, while the low-temperature fluid gradually heats up to near the initial input temperature of the high-temperature fluid before entering the water storage tank, achieving the goal of energy saving and emission reduction.

[0078] According to the stepped counter-current segmented heat exchange device design embodiment of this example, the energy-saving integrated heat exchange shower water heater has significant energy-saving and emission-reduction effects. Due to the size limitations of the test product, the experimental test showed that the heat recovery efficiency of the stepped counter-current segmented heat exchange device is between 0.84 and 0.82 when the water flow rate is 3-6 liters / minute, which is equivalent to a heat exchange efficiency of 168%-164%, or an energy efficiency ratio of 1:6.25-1:5.55. Due to the integrated design, installation and maintenance are simple, and it can be disassembled and cleaned to maintain heat exchange efficiency. It can be used continuously and indefinitely after 20 minutes of water and electricity connection. It has a small water storage capacity, low instantaneous maximum heating power, and minimal impact on the power grid when used simultaneously. There is no mechanical wear and noise, resulting in a long service life. The heat exchange device has stable efficiency, and high or low water temperature has no effect on the heat exchange efficiency. The small-volume insulated heating water tank has low heat loss, fast heating, and high heat preservation efficiency. The structure and principle are explained as follows. Figures 14-20 As shown.

[0079] See Figure 15 Working process and principle:

[0080] Taking a tap water temperature of 12℃ and a semi-enclosed shower room as an example, the equipment is equipped with a vertical rectangular insulated heating water tank of approximately 24.3L. The cold water inlet is located at the bottom, and the hot water outlet is located at the top. With a small heat conduction area at a height of 1.8 meters, it can continuously discharge approximately 22L of stable-temperature hot water. Using a 2.18KW electric heating method, after filling the tank and turning on the power, the water temperature rises by 30℃ in approximately 23.5 minutes, consuming approximately 850.5W of electricity. The water temperature in the tank is 42℃. At this point, when the shower valve is opened, because the heating control temperature measuring device is located near the inlet of the insulated heating water tank, the cold water enters and cools down, immediately after which the power is turned on for heating. Simultaneously, the hot water absorbs heat from the 37℃ surface of the human body, cooling down to approximately 39.5℃. After a period of time, as the surface temperature of the human body rises and the air humidity in the shower room becomes saturated, the vaporization heat absorption and cooling rate gradually decreases, reducing the energy loss of the hot water. The hot water flows from the platform into a stepped counter-current segmented heat exchange device (such as...). Figure 16As shown, the theoretical total regenerative efficiency of the 8 sections is 0.888. Actual measurements at 3L / min to 6L / min show an efficiency of approximately 0.84 to 0.82 (with each section having a regenerative efficiency of approximately 0.4). When the heat exchange tank is filled with water (approximately 14L, in about 2.33 minutes), it gradually enters the highest efficiency heat exchange stage (calculated based on an average efficiency of 0.82). The tap water is heated to (39.5℃ - 12℃) × 0.82 + 12℃ = 34.55℃ before entering the storage tank. When using 30L of water continuously, the heat energy consumed is 30℃ × 30kg × 4.2KJ = 3780KJ, and the regenerative energy exchanged is 22.55℃ × 30kg × 4.2KJ = 2841.3KJ. The power consumption for supplementary heating is 3780KJ - 2841.3KJ = 938.7KJ, and the power consumption is 938700J ÷ 3600s = 260.75W. The electric heating time is approximately 7.18 minutes. The initial heating power consumption is 850.5W + supplementary heating power consumption of 260.75W = 1111.25W. If there is no heat exchange, the power required for normal operation is: (24.3L of water in the storage tank + 30L of water used) × 30℃ × 4200J / (kg.℃) ÷ 3600s = 1900.5W. The initial 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 storage tank is heated for the first time, during continuous use, the energy-saving efficiency per 30L of water is: heat exchange and recuperation 2841.3kJ ÷ 3780kJ = 0.7516, which means an energy saving of 75.16%. After heat exchange, the hot wastewater is cooled to 39.5℃ - 22.55℃ = 16.95℃, which is 4.95℃ higher than the initial temperature of tap water before being discharged into the environment, reducing heat emissions by 75.16%.

[0081] According to experimental test data, with a shower flow rate of 6L / min, continuous use of 30L water for 5 minutes requires simultaneous electric heating for 7.18 minutes. When the shower flow rate is ≤5L / min, continuous use with simultaneous electric heating maintains a stable hot water temperature. In areas where the tap water temperature is below 12℃, the heating control temperature can be appropriately increased (the equipment is designed with a maximum temperature limit of 55℃ to prevent scalding and scale buildup in the heating tank). Various shower temperatures can be met through the mixing valve and flow rate adjustment.

[0082] If the volume is increased to improve the reheat efficiency of the stepped counter-current segmented heat exchange device to 0.9, the tap water temperature in summer is ≥26℃, the bathing temperature is 35℃, and the reheat temperature is [(human body temperature 37℃ + bathing temperature 35℃) ÷ 2 - tap water temperature 26℃] × 0.9 + tap water temperature 26℃ = 35℃. The hot water output temperature is equal to the inlet temperature of the tap water after heat exchange. It can raise the tap water temperature by 9℃ without replenishing energy before the human body cools down. It only needs to provide the initial temperature of the water tank to achieve full-efficiency heat exchange and can be used continuously without energy consumption. This is an energy-saving effect that existing heating devices cannot achieve.

[0083] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A stepped counterflow staged heat exchange device comprising a heat exchange body (1), characterised in that: The heat exchange body (1) includes a heat exchange zone (2) for cooling and heat exchange of hot fluids; The heat exchange zone (2) is provided in several sections. The heat exchange zones (2) are connected to each other and are set at independent intervals. Each heat exchange zone (2) is provided with heat exchange pipes (3) that are connected to each other. A hot fluid flow gap is formed between the heat exchange zone (2) and the heat exchange pipes (3). The heat exchange pipe (3) is provided with an insulating pipe (4) to prevent heat transfer between two adjacent heat exchange zones (2), so that the cold and hot fluids in each heat exchange zone (2) can achieve mutual non-interference and independent heat exchange during the heat exchange process, and each heat exchange zone (2) is separated by the insulating pipe (4), and a stepped temperature difference is formed between each heat exchange zone (2).

2. The stepped counterflow staged heat exchange device of claim 1, wherein: The insulation pipe (4) is located at the connection between two adjacent heat exchange zones (2).

3. The stepped counterflow staged heat exchange device of claim 1, wherein: The hot fluid flows sequentially in the forward direction along each heat exchange zone (2), while the cold fluid flows in the opposite direction to the hot fluid in the heat exchange pipe (3), so that the cold and hot fluids form a stepped counter-current segmented heat exchange in each heat exchange zone (2).

4. The stepped counterflow staged heat exchange device of claim 3, wherein: Each heat exchange zone (2) is provided with a transverse heat exchange zone (5) and a longitudinal heat exchange zone (6) between it 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 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 apparatus of claim 1 wherein: The heat exchange pipes (3) between the two adjacent heat exchange zones (2) are connected by insulated pipes (4) made of insulating material or low thermal conductivity material.

6. The stepped counter-current segmented heat exchange device according to claim 1, characterized in that: The heat exchange body (1) is provided with several partitions (7). One end of the partition (7) is connected to the inside of the heat exchange body (1), and the other end of the partition (7) is provided with a flow-limiting gap (8) between it and the heat exchange body (1), so that the heat exchange body (1) is divided into several interconnected and mutually independent heat exchange zones (2) by several partitions (7).

7. The stepped counter-current segmented heat exchange device according to claim 6, characterized in that: The heat exchange body (1) forms a water tank-shaped heat exchange zone (2) between the inner side and the partition (7). The flow-limiting gap (8) at the connection between two adjacent heat exchange zones (2) forms a reduced cross-section flow-limiting and heat-insulating design. The flow-limiting gap (8) forms a small-area transition zone for hot fluid to enter another heat exchange zone (2) from the heat exchange zone (2). The flow-limiting gap (8) is used to maintain the temperature difference when the heat exchange zones (2) are connected, and to maintain the stepped temperature difference between the heat exchange zones (2).

8. The stepped counter-current segmented heat exchanger according to claim 6, characterized in that: The heat exchange body (1) is provided with a stable water level flow limiting device (9). The stable water level flow limiting device (9) includes a water baffle ring (10) that extends upward along the heat exchange body (1) and forms a water baffle ring to block and slow down the flow rate of hot fluid discharge. The water baffle ring (10) is provided with a drainage channel (11) for discharging wastewater. The drainage channel (11) passes through the water baffle ring (10) from top to bottom. A drain outlet (12) is provided on one side of the upper part of the water baffle ring (10).

9. The stepped counter-current segmented heat exchange device according to claim 6, characterized in that: The heat exchange body (1) includes a base (13) and a cover (14) covering the base (13). The partition (7) is sealed to the base (13) and the cover (14) respectively by a sealing element so that the two adjacent heat exchange zones (2) are connected to each other only through the flow-limiting gap (8). The seat (13) is provided with a heat insulation layer on the periphery and the partition (7). The heat insulation layer and the heat insulation pipe (4) form a heat insulation device for the heat exchange body (1), so that each heat exchange zone (2) does not interfere with each other and exchanges heat independently. When the flow rate of the hot fluid is unstable, the heat exchange efficiency and the instantaneous state of the temperature of each heat exchange zone (2) are maintained. There will be no phenomenon of mutual transfer of heat energy between each heat exchange zone (2) causing a decrease in temperature difference. The cover (14) is provided with an inlet (15) for guiding hot fluid into the heat exchange zone (2).

10. A water heater, comprising a water heater body (16), characterized in that: The water heater body (16) is provided with a stepped counter-current segmented heat exchange device as described in any one of claims 1-9. The heat exchange body (1) is located 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).

Images