Energy-saving dish washing machine

Abstract

The invention relates to the technical field of dish-washing machine equipment, and discloses an energy-saving dish-washing machine which comprises a machine body of the dish-washing machine, the machine body is provided with a first waste heat recovery part, a second waste heat recovery part, a flushing part, a heating water tank and a preheating part, and the heating water tank and the preheating part are connected with the first waste heat recovery part and the second waste heat recovery part respectively. The first waste heat recovery part is used for recovering hot air in the drying area, the second waste heat recovery part is used for recovering waste heat of circulating water, and the water inlet end of the flushing part extends into the heating water tank. Through cooperative work of the two waste heat recovery parts, the hot air in the drying area and the waste heat of the circulating water are efficiently recovered, and waste caused by direct discharge of the waste heat is avoided; meanwhile, waste heat is directionally distributed for preheating cold water, power consumption of a heating water tank is reduced, circulating water is subjected to closed-loop backflow after heat exchange, the energy utilization rate is further increased, and comprehensive operation energy consumption of equipment is remarkably reduced.

Description

Technical Field

[0001] This invention relates to the field of dishwasher equipment technology, and more particularly to an energy-saving dishwasher. Background Technology

[0002] Long-line dishwashers are core equipment for batch processing of tableware in the catering industry. Their workflow typically includes continuous processes such as pre-washing, main washing, rinsing, and drying. During operation, there are two types of high-value medium- and low-temperature waste heat resources: First, the hot and humid air discharged from the drying process carries the latent heat of vaporization released during the drying process of the tableware and the sensible heat from the hot air circulation; Second, the circulating water from the main washing and rinsing processes. Both types of circulating water release a large amount of waste heat into the environment during the continuous spraying and circulation process.

[0003] Currently, most existing long-line dishwashers lack effective waste heat recovery devices, directly venting hot air from the dryer to the outside and wasting the waste heat from the circulating water. This results in a significant amount of energy being consumed meaninglessly, leading to high energy consumption and low waste heat utilization efficiency. Furthermore, in winter when ambient temperatures are low, animal fats (such as lard and tallow) adhering to the surface of tableware tend to solidify and harden, significantly increasing their hardness. The high-pressure water flow and detergent in the existing pre-wash and main wash processes are insufficient to quickly soften and remove the grease. Current technologies often address this by increasing detergent concentration, extending the main wash time, or raising the washing water temperature, which not only increases detergent consumption but also energy consumption. Summary of the Invention

[0004] This invention addresses the shortcomings of existing technologies by providing an energy-saving dishwasher. By incorporating dual waste heat recovery components, it efficiently recovers heat from the drying zone and circulating water. Combined with a directional distribution structure and condition-adaptive control, the waste heat can be selectively used for cold water preheating or pre-softening of grease in dishes, thus solving the problems of waste heat waste, difficulty in handling grease in winter, and limited utilization of waste heat.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: An energy-saving dishwasher includes a dishwasher body, on which are provided a waste heat recovery component one, a waste heat recovery component two, a rinsing component, and a heating water tank and a preheating component respectively connected to the waste heat recovery component one and the waste heat recovery component two. The waste heat recovery component one is used to recover heat from the drying zone, and the waste heat recovery component two is used to recover waste heat from the circulating water. The water inlet end of the rinsing component extends into the heating water tank. The waste heat recovery components one and two can selectively distribute the recovered waste heat to the heating water tank to preheat cold water or to the preheating component to preheat the dishes to soften grease. The rinsing component adopts an existing high-pressure spray structure.

[0006] Preferably, the waste heat recovery component includes a recovery hood fixed above the drying area of ​​the machine body at the hot air backflow opening. A pipe is connected to the recovery hood, and a fan and a temperature sensor are mounted on the pipe. A three-way valve is also mounted on the pipe, with its two output ports connected to a second pipe and a connecting pipe, respectively. The second pipe connects to a preheating component, and the connecting pipe connects to a heating water tank. The recovery hood is made of stainless steel and equipped with a sealing rubber ring, sealing it securely to the machine body to prevent hot air leakage. The first pipe is made of insulated stainless steel and wrapped with an insulation layer to reduce waste heat transfer loss. The fan can be a small centrifugal blower to stably extract hot air. The temperature sensor is a waterproof thermocouple sensor to ensure accurate detection. The three-way valve is an electromagnetic reversing valve for rapid path switching. In summer, although the temperature sensor detects the temperature in real time, it does not participate in the control logic.

[0007] Preferably, the heating water tank is composed of an inner tank and an outer tank, forming a heat exchange space between the inner and outer tanks. A heat exchange component surrounds the inner tank within this space. The outer tank has an air inlet connected to the heat exchange space and an air outlet with a solenoid valve. The air inlet connects to a second waste heat recovery component. One end of the heat exchange component has an inlet pipe connected to an external cold water source, and the other end extends into the inner tank. The outer tank has a third pipe connected to the heat exchange space and connects to both the first and second waste heat recovery components. The outer tank is made of welded stainless steel. The heat exchange space is filled with an insulation layer to reduce heat loss. The inner tank is a conventional heating water tank with an electric heating element for water heating. The solenoid valve is a normally closed solenoid shut-off valve used to control the orderly discharge of waste gas from the heat exchange space. The inner tank contains a liquid level sensor structure electrically connected to a controller to provide a water shortage warning (this liquid level sensor tank is a conventional technology).

[0008] Preferably, the second waste heat recovery component includes a heat exchanger and a circulating water pipe for conveying filtered circulating water to the heat exchanger. The circulating water pipe is connected to a bypass pipe via a three-way connector. A bypass valve is installed on the bypass pipe. The heat exchanger is connected to an air inlet pipe, and a second fan is installed on the air inlet pipe. A second three-way valve and a second temperature sensor are installed on the third pipe. The output ends of the circulating water pipe and the second heat exchanger are both connected to the heating water tank. The output port of the second three-way valve is connected to the preheating component. The heat exchanger can be a finned tube heat exchanger to improve the heat exchange efficiency between the circulating water and the air. The circulating water pipe is made of stainless steel. The bypass valve is an electromagnetic shut-off valve, which can flexibly control whether the circulating water enters the heat exchanger. The second fan can be an axial flow exhaust fan, used to draw ambient temperature air for heat exchange with the circulating water. The second temperature sensor is the same model as the first temperature sensor to ensure consistent detection. The second three-way valve has the same structure as the first three-way valve to achieve rapid switching of the circuit. Under summer operating conditions, the second fan and the second temperature sensor are both in a stopped / dormant state and do not participate in operation.

[0009] Preferably, the preheating component includes an air outlet hood located at the air inlet at the end of the bowl-placement part of the machine body. The air outlet hood is connected to a pipe four, and a fan three is mounted on the pipe four. The pipe four is connected to both the pipe two of the waste heat recovery component one and the three-way valve two of the waste heat recovery component two. The air outlet hood faces downwards from the bowl-placement conveying track. The pipe four is made of the same material and has the same insulation structure as the pipe one to reduce waste heat transmission loss. A sealing gasket is provided at the connection point between the pipe four and the pipe two and the three-way valve two to prevent hot air leakage. The fan three can be a centrifugal blower used to pressurize the hot air and stably deliver it to the air outlet hood. In summer operating conditions, the fan three is in a stopped state, and the preheating component as a whole does not work.

[0010] Preferably, it also includes a controller. Temperature sensor one of the waste heat recovery component one and temperature sensor two of the waste heat recovery component two are electrically connected to the controller. The controller is also electrically connected to fan one, fan two, fan three, three-way valve one, three-way valve two, and solenoid valve. The controller is a PLC programmable controller, which is installed in a control box on the side wall of the machine body. The controller realizes the linkage control of each component through control lines.

[0011] Preferably, in winter, the controller controls three-way valves one and two based on the detection results of temperature sensor one and temperature sensor two, according to the grease softening requirements, to direct the higher-temperature residual heat to the preheating element, so as to preheat the bowls and plates to soften the grease.

[0012] Preferably, in summer conditions, the controller, based on the requirement of no need for grease preheating, controls the bypass valve to close and distributes all the heat recovered by the waste heat recovery unit to the heating water tank to preheat the cold water.

[0013] Preferably, the output end two of the heat exchanger is connected to the inner tank of the heating water tank through a delivery pipe, which is used to transport the circulating water after heat exchange back to the inner tank.

[0014] Preferably, the heat exchanger is a copper heat exchange tube, which is arranged around the inner casing within the heat exchange space.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention utilizes dual waste heat recovery components to efficiently recover the heat from the drying zone and the waste heat from the circulating water, avoiding the direct discharge and waste of waste heat. At the same time, the waste heat is directed to be used for cold water preheating, reducing the power consumption of the heating water tank. The circulating water is returned in a closed loop after heat exchange, further improving the energy utilization rate and significantly reducing the overall energy consumption of the equipment. Furthermore, it is adaptable to different working conditions in winter and summer. In winter, the high-temperature waste heat is directed to the preheating parts to soften solidified grease, reducing the amount of detergent and cleaning time, and improving the cleaning qualification rate. In summer, unnecessary parts are shut down, and the waste heat is concentrated to preheat cold water, taking into account both energy saving and practicality. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 These are structural views of the various components of the present invention; Figure 3 This is a cross-sectional view of the heating water tank of the present invention; Figure 4 This is a schematic diagram of the overall system of the present invention; Figure 5 This is a schematic diagram of heat distribution in the waste heat recovery component of the present invention when the temperature is high; Figure 6 This is a schematic diagram of heat distribution when the temperature of the waste heat recovery component 2 of the present invention is high; Figure 7 This is a schematic diagram of the path system for summer use according to the present invention.

[0018] Drawing number explanation: 1. Main body; 2. Waste heat recovery component one; 21. Recovery hood; 22. Pipe one; 23. Fan one; 24. Temperature sensor one; 25. Three-way valve one; 26. Pipe two; 3. Waste heat recovery component two; 31. Circulating water pipe; 32. Heat exchanger; 33. Temperature sensor two; 34. Three-way valve two; 35. Air inlet pipe; 36. Fan two; 37. Bypass pipe; 38. Bypass valve; 39. Delivery pipe; 4. Heating water tank; 41. Housing; 411. Inner housing; 412. Heat exchange component; 413. Outer housing; 42. Solenoid valve; 43. Pipe three; 44. Water inlet pipe; 5. Preheating component; 51. Air outlet hood; 52. Pipe four; 53. Fan three; 6. Flushing components. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to the accompanying drawings.

[0020] The following description is intended to disclose the invention so that those skilled in the art can implement it. The preferred embodiments described below are merely examples, and other obvious modifications will be apparent to those skilled in the art. The basic principles of the invention defined in the following description can be used in other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the invention.

[0021] Those skilled in the art should understand that, in the disclosure of this invention, the terms "longitudinal," "lateral," "upper," "lower," "left," "right," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or position based on the orientation or positional relationship shown in the accompanying drawings. They are merely simplified descriptions for the convenience of describing this invention and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limitations on this invention.

[0022] It is understood that the term "a" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple, and the term "a" should not be understood as a limitation on the number.

[0023] Example: Please see Figure 1-7 An energy-saving dishwasher includes a dishwasher body 1, on which a waste heat recovery component 2, a waste heat recovery component 3, a rinsing component 6, and a heating water tank 4 and a preheating component 5 respectively connected to the waste heat recovery component 2 and the waste heat recovery component 3. The waste heat recovery component 2 is used to recover heat from the drying zone, and the waste heat recovery component 3 is used to recover waste heat from the circulating water. The water inlet end of the rinsing component 6 extends into the heating water tank 4. The waste heat recovery components 2 and 3 can selectively distribute the recovered waste heat to the heating water tank 4 to preheat cold water or to the preheating component 5 to preheat the dishes and soften grease. The rinsing component 6 adopts an existing high-pressure spray structure.

[0024] Waste heat recovery component 2 includes a recovery cover 21 fixed above the drying area of ​​the machine body 1 at the hot air backflow opening. The recovery cover 21 is connected to a pipe 22, which is equipped with a fan 23 and a temperature sensor 24. The pipe 22 is also equipped with a three-way valve 25. The two output ports of the three-way valve 25 are respectively connected to a pipe 26 and a connecting pipe. The pipe 26 is connected to the preheating component 5, and the connecting pipe is connected to the heating water tank 4. The recovery cover 21 is made of stainless steel and is equipped with a sealing rubber ring to seal and fix it to the machine body 1 to prevent hot air leakage. The pipe 22 is made of insulated stainless steel pipe and wrapped with an insulation layer to reduce waste heat transmission loss. The fan 23 can be a small centrifugal blower to stably extract hot air. The temperature sensor 24 is a waterproof thermocouple sensor to ensure accurate detection. The three-way valve 25 is an electromagnetic reversing valve to realize rapid path switching. In summer operation, the temperature sensor 24 detects the temperature in real time but does not participate in the control logic.

[0025] The heating water tank 4 has a casing 41 consisting of an inner casing 411 and an outer casing 413. A heat exchange space is formed between the inner casing 411 and the outer casing 413. A heat exchange element 412 surrounds the inner casing 411 within the heat exchange space. The outer casing 413 has an air inlet end communicating with the heat exchange space and an air outlet end equipped with a solenoid valve 42. The air inlet end is connected to the waste heat recovery element 3. One end of the heat exchange element 412 has a water inlet pipe 44 connected to an external cold water source, and the other end extends into the inner casing 411. The outer casing 413 has a pipe 43 communicating with the heat exchange space. It is connected to waste heat recovery component 1 2 and waste heat recovery component 2 3 through pipe 3 43. Its outer casing 413 is made of stainless steel welded and formed. The heat exchange space is filled with an insulation layer to reduce heat loss. Its inner casing 411 is a heating water tank 4 with electric heating tube for water heating in the prior art. The solenoid valve 42 is a normally closed solenoid shut-off valve used to control the orderly discharge of waste gas in the heat exchange space. Its inner casing 411 is equipped with a liquid level sensing structure, which is electrically connected to the controller to realize water shortage warning (this water tank with liquid level sensing structure is the prior art).

[0026] Waste heat recovery component 2 3 includes a heat exchanger 32 and a circulating water pipe 31 for conveying filtered circulating water to the heat exchanger 32. The circulating water pipe 31 is connected to a bypass pipe 37 via a three-way connector. A bypass valve 38 is installed on the bypass pipe 37. The heat exchanger 32 is connected to an air inlet pipe 35, and a fan 2 36 is installed on the air inlet pipe 35. A three-way valve 2 34 and a temperature sensor 2 33 are installed on the pipe 3 43. The output ends of the circulating water pipe 31 and the heat exchanger 32 are both connected to the heating water tank 4. The output port of the three-way valve 2 34 is connected to the preheating component 5. The heat exchanger 32 can be finned. The tubular heat exchanger improves the heat exchange efficiency between circulating water and air. The circulating water pipe 31 is made of stainless steel. The bypass valve 38 is an electromagnetic shut-off valve, which can flexibly control whether circulating water enters the heat exchanger 32. The second fan 36 can be an axial flow fan, used to draw ambient temperature air for heat exchange with circulating water. The second temperature sensor 33 is the same model as the first temperature sensor 24 to ensure consistent detection. The second three-way valve 34 has the same structure as the first three-way valve 25 to achieve rapid switching of the passage. Under summer conditions, the second fan 36 and the second temperature sensor 33 are both in a stopped / dormant state and do not participate in the operation.

[0027] The preheating component 5 includes an air outlet hood 51 located at the air inlet at the end of the bowl of the machine body 1. The air outlet hood 51 is connected to a pipe 4 52, and a fan 3 53 is mounted on the pipe 4 52. The pipe 4 52 is connected to the pipe 2 26 of the waste heat recovery component 1 and the three-way valve 2 34 of the waste heat recovery component 2. The air outlet hood 51 faces downwards from the bowl conveying track. The pipe 4 52 is made of the same material and has the same insulation structure as the pipe 1 22 to reduce waste heat transmission loss. A sealing gasket is provided at the connection between the pipe 4 52 and the pipe 2 26 and the three-way valve 2 34 to prevent hot air leakage. The fan 3 53 can be a centrifugal blower, which is used to pressurize the hot air and stably deliver it to the air outlet hood 51. In summer, the fan 3 53 is in a stopped state, and the preheating component 5 as a whole does not work.

[0028] It also includes a controller. Temperature sensor 24 of waste heat recovery component 1 and temperature sensor 33 of waste heat recovery component 2 are electrically connected to the controller. The controller is also electrically connected to fan 1 23, fan 2 36, fan 3 53, three-way valve 1 25, three-way valve 2 34, and solenoid valve 42. The controller is a PLC programmable controller, which is installed in the control box on the side wall of the machine body 1. The controller realizes the linkage control of each component through control lines. Among them, three-way valve 1 25 and three-way valve 2 34 can be electric three-way ball valves when in use.

[0029] In winter, the controller, based on the detection results of temperature sensor 24 and temperature sensor 33, controls three-way valve 25 and three-way valve 34 according to the grease softening requirements, directs the higher-temperature residual heat to the preheating component 5 to preheat the bowls and plates for grease softening.

[0030] In summer, based on the requirement that no grease preheating is needed, the controller controls the bypass valve 38 to close and distributes all the heat recovered by the waste heat recovery unit 2 to the heating water tank 4 to preheat the cold water.

[0031] The output end of the heat exchanger 32 is connected to the inner box 411 of the heating water tank 4 through the conveying pipe 39, which is used to transport the circulating water after heat exchange back to the inner box 411. The heat exchange element 412 is a copper heat exchange tube, which is arranged around the inner box 411 in the heat exchange space.

[0032] Winter start-up preparation: After the dishwasher starts up, the controller recognizes the winter operating conditions (which can be manually set or automatically recognized by the ambient temperature sensor; in this embodiment, the operating mode can be manually switched), controls the bypass valve 38 to open, allowing some circulating water to enter the heat exchanger 32, and simultaneously starts the first fan 23, the second fan 36, and the third fan 53 to enter the waste heat recovery and distribution state.

[0033] Waste heat recovery: When the hot air in the drying zone is backflowed, the fan 23 starts and draws the backflowing hot air into the pipe 22. The temperature sensor 24 detects the temperature of the hot air in the pipe 22 and transmits the data to the controller. After filtration, the circulating water flows through the circulating water pipe 31. Part of the circulating water enters the input end 1 of the heat exchanger 32 through the bypass valve 38. The second fan 36 starts and draws in ambient temperature air into the input end 2 of the heat exchanger 32. The air and the circulating water exchange heat fully in the heat exchanger 32. The air absorbs heat and becomes hot air, which enters the third pipe 43 from the output end 1 of the heat exchanger 32. The second temperature sensor 33 detects the temperature of the hot air output by the heat exchanger 32 and transmits the data to the controller. The circulating water after heat exchange flows back from the output end 2 of the heat exchanger 32 to the inner tank 411 of the heating water tank 4 through the delivery pipe 39.

[0034] Waste heat temperature comparison and path switching: If the controller receives data showing that the hot air temperature detected by temperature sensor 24 is greater than the hot air temperature detected by temperature sensor 33, the controller controls the three-way valve 25 to switch, connecting pipe 22 and pipe 26. At the same time, the controller controls the three-way valve 34 to switch, connecting the output end of heat exchanger 32 to the air inlet of heating water tank 4. At this time, the hot air from waste heat recovery component 2 enters pipe 4 52 through pipe 22, three-way valve 25, and pipe 26, and the hot air from waste heat recovery component 3 enters the heat exchange space of heating water tank 4 through pipe 3 43, three-way valve 34, and connecting pipe.

[0035] If the controller receives data showing that the hot air temperature detected by temperature sensor 233 is greater than the hot air temperature detected by temperature sensor 124, the controller controls the three-way valve 234 to switch, connecting pipe 343 and pipe 452. At the same time, the controller controls the three-way valve 125 to switch, connecting pipe 122 and connecting pipe. At this time, the hot air from waste heat recovery component 23 flows through pipe 343 and three-way valve 234 into pipe 452, and the hot air from waste heat recovery component 12 flows through pipe 122, three-way valve 125, and connecting pipe into the heat exchange space of heating water tank 4.

[0036] Waste heat utilization: Grease pre-softening: The high-temperature waste heat in pipe 4 52 is blown by the fan 3 53 through the air outlet 51 to the bowl at the end of the bowl in the machine body 1. The hot air evenly covers the surface of the bowl and preheats and softens the solidified grease. The softened grease is easier to remove by the subsequent rinsing of the component 6. Cold water preheating: The waste heat gas entering the heat exchange space of the heating water tank 4 exchanges heat with the copper heat exchange tubes surrounding the inner box 411. The cold water from the outside enters the heat exchange tube through one end of the heat exchange component 412, absorbs the waste heat of the hot air and becomes warm water. The warm water flows into the inner box 411 from the other end of the heat exchange tube. When the pressure in the heat exchange space is too high, the solenoid valve 42 can be opened by the controller to discharge the waste gas after heat exchange.

[0037] The electric heating element in the inner chamber 411 heats the preheated warm water to the required washing temperature. The chamber 41 is equipped with a device to detect and monitor the water level (water level monitoring is a publicly available technology and will not be described in detail). When the water level is insufficient, preheated cold water is automatically added. The water inlet of the rinsing component 6 draws hot water from the inner chamber 411 to spray and clean the preheated dishes. The circulating water after cleaning is filtered by the filter system on the dishwasher and then circulated again through the circulating water pipe 31. Some of the circulating water continues to participate in waste heat recovery, forming a closed-loop operation.

[0038] Summer operating procedures: In summer when the temperature is high, there is no need for grease pre-softening. After the dishwasher is started, the controller recognizes the summer operating conditions (manual setting or automatic recognition) and controls the bypass valve 38 to close. The circulating water does not enter the heat exchanger 32 and flows directly back to the inner chamber 411 of the heating water tank 4 through the circulating water pipe 31. At the same time, the fan 1 23 is started, while the fan 2 36 and the fan 3 53 are in the off state. The three-way valve 1 25 is switched to the state of waste heat guiding the heating water tank 4 by default.

[0039] Waste heat recovery: When the hot air in the drying zone is backflushed, the fan 23 starts and draws the backflushed hot air into the pipe 22. The waste heat in the pipe 22 enters the heat exchange space of the heating water tank 4 through the three-way valve 25 and the connecting pipe. The cold water from the outside enters the copper heat exchange tube through one end of the heat exchange component 412. After absorbing the waste heat of the hot air in the heat exchange space, it becomes warm water. The warm water flows into the inner box 411. The exhaust gas after heat exchange is discharged through the solenoid valve 42 (opens when the pressure is too high).

[0040] The electric heating element in the inner chamber 411 heats the preheated warm water to the required cleaning temperature. The liquid level sensor monitors the water level and replenishes cold water. The rinsing component 6 draws hot water from the inner chamber 411 to spray and clean the dishes. The circulating water is filtered and then circulated back. No residual heat is used for grease preheating, and the focused cold water preheating saves energy.

[0041] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the accompanying drawings are merely examples and do not limit the present invention. The objectives of the present invention have been fully and effectively achieved. The functions and structural principles of the present invention have been shown and explained in the embodiments, and any modifications or variations of the embodiments of the present invention may be made without departing from the stated principles.

Claims

1. An energy-saving dishwasher, characterized in that, The dishwasher includes a body (1), which is provided with a waste heat recovery component 1 (2), a waste heat recovery component 2 (3), a rinsing component (6), and a heating water tank (4) and a preheating component (5) respectively connected to the waste heat recovery component 1 (2) and the waste heat recovery component 2 (3); The first waste heat recovery component (2) is used to recover the heat from the drying zone, the second waste heat recovery component (3) is used to recover the waste heat from the circulating water, and the inlet end of the flushing component (6) extends into the heating water tank (4). The waste heat recovery components 1 (2) and 2 (3) can selectively distribute the recovered waste heat to the heating water tank (4) to preheat cold water or to the preheating component (5) to preheat the dishes and soften the grease.

2. The energy-saving dishwasher according to claim 1, characterized in that, The waste heat recovery component 1 (2) includes a recovery cover (21) fixed above the drying area of ​​the machine body (1) at the corresponding hot air backflow opening. The recovery cover (21) is connected to a pipe 1 (22). The pipe 1 (22) is equipped with a fan 1 (23) and a temperature sensor 1 (24). The pipe 1 (22) is also equipped with a three-way valve 1 (25). The two output ports of the three-way valve 1 (25) are respectively connected to a pipe 2 (26) and a connecting pipe. The pipe 2 (26) is connected to the preheating component (5), and the connecting pipe is connected to the heating water tank (4).

3. An energy-saving dishwasher according to claim 2, characterized in that, The heating water tank (4) is composed of an inner tank (411) and an outer tank (413). A heat exchange space is formed between the inner tank (411) and the outer tank (413). A heat exchange element (412) surrounding the inner tank (411) is provided in the heat exchange space. The outer casing (413) is provided with an air inlet end that communicates with the heat exchange space and an air outlet end with a solenoid valve (42). The air inlet end is connected to the second waste heat recovery component (3). One end of the heat exchange component (412) is provided with a water inlet pipe (44) connected to an external cold water source, and the other end extends into the inner casing (411). The outer casing (413) is provided with a third pipe (43) that communicates with the heat exchange space, and is connected to the first waste heat recovery component (2) and the second waste heat recovery component (3) through the third pipe (43).

4. An energy-saving dishwasher according to claim 3, characterized in that, The waste heat recovery component 2 (3) includes a heat exchanger (32) and a circulating water pipe (31) for conveying filtered circulating water to the heat exchanger (32). The circulating water pipe (31) is connected to a bypass pipe (37) through a three-way connector. A bypass valve (38) is provided on the bypass pipe (37). The heat exchanger (32) is connected to an air inlet pipe (35). A second fan (36) is installed on the air inlet pipe (35). A second three-way valve (34) and a second temperature sensor (33) are provided on the third pipe (43). The output ends of the circulating water pipe (31) and the heat exchanger (32) are both connected to the heating water tank (4). The output port of the second three-way valve (34) is connected to the preheating component (5).

5. An energy-saving dishwasher according to claim 1, characterized in that, The preheating component (5) includes an air outlet hood (51) located at the air inlet at the end of the bowl of the machine body (1). The air outlet hood (51) is connected to a pipe four (52), and a fan three (53) is installed on the pipe four (52). The pipe four (52) is connected to the pipe two (26) of the waste heat recovery component one (2) and the three-way valve two (34) of the waste heat recovery component two (3).

6. An energy-saving dishwasher according to claim 5, characterized in that, It also includes a controller. Temperature sensor 1 (24) of the waste heat recovery component 1 (2) and temperature sensor 2 (33) of the waste heat recovery component 2 (3) are both electrically connected to the controller. The controller is also electrically connected to fan 1 (23), fan 2 (36), fan 3 (53), three-way valve 1 (25), three-way valve 2 (34), and solenoid valve (42).

7. An energy-saving dishwasher according to claim 6, characterized in that, In winter, the controller controls three-way valves one (25) and two (34) based on the detection results of temperature sensor one (24) and temperature sensor two (33) and the grease softening requirement, directing the higher temperature residual heat to the preheating component (5) to preheat the bowls and plates to soften the grease.

8. An energy-saving dishwasher according to claim 6, characterized in that, In summer, the controller controls the bypass valve (38) to close based on the working condition requirement of not needing grease preheating, and distributes all the heat recovered by the waste heat recovery component (2) to the heating water tank (4) to preheat the cold water.

9. An energy-saving dishwasher according to claim 4, characterized in that, The output end of the heat exchanger (32) is connected to the inner tank (411) of the heating water tank (4) through the delivery pipe (39) to transport the circulating water after heat exchange back to the inner tank (411).

10. An energy-saving dishwasher according to claim 3, characterized in that, The heat exchanger (412) is a copper heat exchange tube, which is arranged around the inner box (411) in the heat exchange space.

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