Heat exchange system

Abstract

The embodiment of the invention relates to the technical field of heat exchange, in particular to a heat exchange system. The heat exchange system comprises a first evaporator, a first heat exchanger and a first water storage tank. The first evaporator is provided with a first inner cavity for containing water, the bottom of the first inner cavity communicates with a first switch valve for controlling air introduction, the top of the first inner cavity communicates with a first vacuum pump, and a first perforated plate is arranged on the side, close to the first switch valve, of the wall of the first inner cavity. Air introduced by the first switch valve passes through the first perforated plate and then generates a plurality of bubbles in water, the first vacuum pump extracts gas in the first inner cavity and enables the pressure in the first inner cavity to reach a preset condition, and the water in the first inner cavity generates a bubble enhanced evaporation phenomenon; the first heat exchanger communicates with the first vacuum pump. According to the heat exchange system, when the air source heat pump type water heater is used in a cold region, the liquidity of refrigerant water is guaranteed, and the application territorial range of the air source heat pump type water heater with water as the refrigerant is expanded.

Description

TECHNICAL FIELD

[0001] The embodiment of the present application relates to heat exchange technology field, especially relates to a heat exchange system. BACKGROUND

[0002] The air source heat pump type water heater is a kind of water heater that uses outdoor air as heat source, in operation, heat transfer working medium in evaporator absorbs heat from the environment in air when evaporating, working medium vapor rises in pressure and temperature after being compressed by compressor, high-temperature vapor condenses into liquid when passing through the special annular pipe of water storage tank, and the heat of high-temperature vapor is transferred to water in water storage tank, so that hot water is produced for production and life.

[0003] The refrigerant of the existing air source heat pump type water heater is the third generation of synthetic refrigerant, such as hydrogen fluoride carbon (HFC) compound, or even the second generation of refrigerant, such as chlorofluorocarbon (CFC) compound. Due to the adverse effects of fluorine-containing refrigerants on the environment, the use of fluorine-containing refrigerants is gradually limited worldwide. Water has the advantages of zero ODP (Ozone Depletion Potential), zero GWP (Global Warming Potential), high vaporization heat (44kJ / mol at room temperature), high theoretical COP (Coefficient Of Performance) value, non-toxic, no safety concerns, readily available, low price, no water quality requirements, no regulatory restrictions, high chemical stability and non-flammable, etc. It is a kind of excellent natural refrigerant, which has been proposed to be used as refrigerant in air source heat pump in recent years.

[0004] However, the freezing point of water is high, and it is easy to freeze in winter in cold regions, which causes the air source heat pump type water heater to be unable to be used in cold regions, and limits the application area of the air source heat pump type water heater using water as refrigerant. SUMMARY

[0005] The purpose of the embodiment of the present application is to provide a heat exchange system, which can ensure the flowability of refrigerant water when using air source heat pump type water heater in cold regions, and expand the application area of air source heat pump type water heater using water as refrigerant.

[0006] To solve the above technical problems, the embodiment of the present application provides a heat exchange system, which comprises a first evaporator, a first heat exchanger and a first water storage tank. The first evaporator is provided with a first inner cavity containing water, the bottom of the first inner cavity is communicated with a first switch valve for controlling air to enter, the top of the first inner cavity is communicated with a first vacuum pump, the cavity wall of the first inner cavity is provided with a first porous plate near the first switch valve, the air entering through the first switch valve generates a plurality of bubbles in the water after passing through the first porous plate, the first vacuum pump extracts the gas in the first inner cavity and makes the pressure in the first inner cavity reach a preset condition, and the water in the first inner cavity undergoes a bubble-enhanced evaporation phenomenon; the first heat exchanger is communicated with the first vacuum pump, and the gas extracted by the first vacuum pump is condensed into liquid water after passing through the first heat exchanger; the first water storage tank comprises a water inlet communicated with a water source and a water outlet for supplying hot water, the first water storage tank is provided with a first pipeline capable of exchanging heat with the first heat exchanger, and the water in the first water storage tank flows back into the first water storage tank after being heated by the first heat exchanger; the first evaporator and the first water storage tank are both double-layer insulation structures, the material of the first pipeline and the material of the first heat exchanger are both heat insulation materials, and the material of the pipeline communicated between the first evaporator and the first heat exchanger is a heat insulation material.

[0007] The heat exchange system provided by the embodiment of the present application can increase the contact area between the gas and the liquid water by setting the first evaporator containing water, introducing air into the first evaporator through the first switch valve, and generating a large number of bubbles after the air passes through the first porous plate, thereby greatly enhancing the evaporation rate of the water, and the water in the first evaporator undergoes a bubble-enhanced evaporation phenomenon. By using the physical principle of evaporation heat absorption, the heat of the water at the lower end of the first evaporator is absorbed to become cold water, and at the same time, the gas after evaporation passes through the first heat exchanger, and the absorbed heat is conducted to the water stored in the first water storage tank through the first pipeline, so that the water in the first water storage tank becomes hot water, and the hot water is obtained through the water outlet for daily use. By setting the first evaporator and the first water storage tank as double-layer insulation structures, and using heat insulation materials for the first pipeline, the first heat exchanger and the communicating pipeline, the heat insulation effect of the entire heat exchange system is improved, and the flowability of the refrigerant water is ensured when the air source heat pump type water heater is used in cold regions, thereby expanding the application region of the air source heat pump type water heater using water as the refrigerant.

[0008] In some embodiments, the heat exchange system further comprises a second water storage tank, one end of the second water storage tank is communicated with the first evaporator, and the other end of the second water storage tank is communicated with the first heat exchanger, the second water storage tank is used for providing liquid water to the first evaporator and receiving the liquid water condensed by the first heat exchanger.

[0009] In some embodiments, the heat exchange system further comprises a second evaporator and a second heat exchanger, the second evaporator is provided with a second inner cavity containing water, the bottom of the second inner cavity is communicated with a second switch valve for controlling air intake, the top of the second inner cavity is communicated with a second vacuum pump, the wall of the second inner cavity is provided with a second porous plate near the second switch valve, the air entering the second switch valve generates a plurality of bubbles in the water after passing through the second porous plate, the second vacuum pump extracts the gas in the second inner cavity and makes the pressure in the second inner cavity reach a preset condition, and the water in the second inner cavity undergoes bubble-enhanced evaporation; the second heat exchanger is communicated with the second vacuum pump, and the gaseous water extracted by the second vacuum pump is condensed into liquid water through the second heat exchanger; the first evaporator is provided with a second pipeline capable of exchanging heat with the second heat exchanger, and the cold water in the first evaporator is heated by the second heat exchanger and then flows back into the first evaporator.

[0010] In some embodiments, the heat exchange system further comprises a third water storage tank, one end of the third water storage tank is communicated with the second evaporator, and the other end of the third water storage tank is communicated with the second heat exchanger, the third water storage tank is used to provide liquid water to the second evaporator and receive liquid water condensed by the second heat exchanger.

[0011] In some embodiments, a water pump is arranged on the path from the third water storage tank to the second evaporator, and a third pipeline is arranged on the path from the second evaporator to the third water storage tank.

[0012] In some embodiments, the materials of the second pipeline and the third pipeline are all thermal insulation materials, the pipeline communicated between the second evaporator and the second heat exchanger is made of thermal insulation material, and the pipeline communicated between the first evaporator and the second heat exchanger is made of thermal insulation material.

[0013] In some embodiments, the second evaporator, the second water storage tank and the third water storage tank are all double-layer thermal insulation structures.

[0014] In some embodiments, a first exhaust valve is arranged on the path of the liquid water condensed by the first heat exchanger flowing back to the second water storage tank, and a second exhaust valve is arranged on the path of the liquid water condensed by the second heat exchanger flowing back to the third water storage tank.

[0015] In some embodiments, the outer edge of the first porous plate completely matches the inner wall of the first evaporator, and the outer edge of the second porous plate completely matches the inner wall of the second evaporator.

[0016] In some embodiments, the cavity wall below the air extraction port of the first vacuum pump and the cavity wall below the air extraction port of the second vacuum pump are respectively provided with a plurality of baffles.

[0017] In some embodiments, the baffles in the first evaporator are provided with two baffles which are installed staggered, and the baffles in the second evaporator are provided with two baffles which are installed staggered.

[0018] In some embodiments, the first switch valve and the second switch valve are both needle valves.

[0019] In some embodiments, the air pressure in the first inner cavity and the second inner cavity is between 150 mbar and 300 mbar.

[0020] In some embodiments, the heat exchange system further comprises a duct unit, the duct unit comprising a fan and a coil pipe, the coil pipe being in communication with the second evaporator or the first water tank, and the low-temperature or high-temperature fluid flowing into the coil pipe, the cold air or hot air emitted outside the coil pipe being blown into the environment by the fan.

[0021] In some embodiments, the heat exchange system further comprises a first four-way valve and a second four-way valve, two ports of the first four-way valve being in series on the communication path of the cold water in the second evaporator to the coil pipe, the other two ports of the first four-way valve being in series on the communication path of the hot water in the first water tank to the coil pipe; two ports of the second four-way valve being arranged on the communication path of the water in the coil pipe to the second evaporator, the other two ports of the second four-way valve being arranged on the communication path of the water in the coil pipe to the first water tank. BRIEF DESCRIPTION OF DRAWINGS

[0022] One or more embodiments are illustrated by way of example in the figures that form a part of this disclosure and which are shown by way of illustration in the drawings and are not intended to limit the scope of the embodiments. Like references numerals and descriptions used herein bear with them semantic relationships and can be intentionally repeated in different figures for the sake of clarity and conciseness.

[0023] Figure 1 is a structural schematic diagram of a heat exchange system provided by some embodiments of the present application;

[0024] Figure 2 is a phase diagram of water.

[0025] BRIEF DESCRIPTION OF DRAWINGS 11 - first evaporator; 111 - first inner cavity; 112 - first switch valve; 113 - first vacuum pump; 114 - first porous plate; 115 - second pipe; 12 - first heat exchanger; 13 - first water tank; 131 - water inlet; 132 - water outlet; 133 - first pipe; 14 - second water tank; 15 - second evaporator; 151 - second inner cavity; 152 - second switch valve; 153 - second vacuum pump; 154 - second porous plate; 16 - second heat exchanger; 17 - third water tank; 18 - water pump; 19 - third pipe; 20 - first exhaust valve; 21 - second exhaust valve; 22 - baffle; 23 - duct unit; 231 - fan; 232 - coil pipe; 24 - first four-way valve; 25 - second four-way valve. DETAILED DESCRIPTION

[0026] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the various embodiments of the present application will be described in detail below with the drawings. However, it can be understood by those skilled in the art that, in the various embodiments of the present application, many technical details are proposed in order to make the readers better understand the present application. However, the technical solutions claimed by the present application can be implemented even without these technical details and various changes and modifications based on the following embodiments. The division of the following various embodiments is for the convenience of description, and should not constitute any limitation on the specific implementation of the present application, and the various embodiments can be combined and referred to each other without contradiction.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this application; the terms "include" and "have" and any variations thereof used in the specification and claims of this application and the above description of drawings are intended to cover the inclusion not the exclusion of one or more elements.

[0028] In the description of the embodiments of the present application, the technical terms "first", "second", and the like are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0029] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connection", "connection" and the like should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integral; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0030] After the Montreal Protocol was adopted in 1987, the ozone-depleting chlorofluorocarbon (CFC) refrigerant was first banned. The Kigali Amendment in 2016 requires a 75% reduction in the use of high global warming potential hydrofluorocarbon (HFC) refrigerants. The more stringent "F-gas" regulations of the European Union in 2023 require the ban of HFCs and hydrofluoroolefin (HFOs) by 2035. This has led to strict restrictions on the application of synthetic refrigerants in the field of refrigeration, air conditioning and heat pump, which has forced us to find environmentally friendly refrigerants.

[0031] Air source heat pump is a heat pump machine with outdoor air as heat source. In operation, the heat transfer working medium in the evaporator absorbs heat from the air environment when evaporating. The working medium vapor rises in temperature after being compressed by the compressor. The high-temperature vapor condenses into liquid when passing through the special annular pipe on the outer surface of the water storage tank, and the heat of the high-temperature vapor is transferred to the water in the water storage tank, thereby producing hot water for production and life. The refrigerant of the existing air source heat pump water heater is the third generation of synthetic refrigerant, such as hydrogen fluoride carbon (HFC) compound, or even the second generation of refrigerant, such as chlorofluorocarbon (CFC) compound.

[0032] The use of synthetic hydrogen fluoride compound and chlorofluorocarbon compound is strictly limited because they can destroy the ozone layer in the atmospheric environment and cause global warming. Water has the advantages of zero ODP, zero GWP, high vaporization heat (44 kJ / mol at room temperature), high theoretical efficiency coefficient value, no toxicity, no safety concerns, easy availability, low price, no water quality requirements, no regulatory restrictions, high chemical stability, and non-flammability, and is an excellent natural refrigerant. In recent years, it has been proposed to be used as a refrigerant in air source heat pumps.

[0033] However, the freezing point of water is high, and it is easy to freeze in winter in cold regions, which causes the air source heat pump water heater to be unable to be used in cold regions, limiting the application area of the air source heat pump water heater using water as a refrigerant.

[0034] Therefore, in order to ensure the flowability of the refrigerant water when using the air source heat pump water heater in cold regions, and expand the application area of the air source heat pump water heater using water as a refrigerant, the heat exchange system provided by the embodiments of the present application comprises a first evaporator containing water, the inside of the first evaporator is vacuumized, and air is introduced through a first switch valve. A large number of air bubbles are generated after the air passes through the first porous plate, the contact area between the gas and the liquid water is increased, the evaporation rate of the water is greatly increased, and the water in the first evaporator undergoes bubble-enhanced evaporation. According to the physical principle of evaporation heat absorption, the heat of the water at the lower end of the first evaporator is absorbed and becomes cold water, and at the same time, the gas after evaporation passes through the first heat exchanger, and the absorbed heat is conducted to the water stored in the first water storage tank through the first pipeline, and the water in the first water storage tank becomes hot water, which is obtained through the water outlet for daily use. The first evaporator and the first water storage tank are provided as a double-layer insulation structure, the material of the first pipeline, the first heat exchanger and the connecting pipeline is an insulation material, the insulation effect of the entire heat exchange system is increased, the flowability of the refrigerant water is ensured when using the air source heat pump water heater in cold regions, and the application area of the air source heat pump water heater using water as a refrigerant is expanded.

[0035] Some embodiments of the present application will be described below. Figure 1 The heat exchange system provided by some embodiments of the present application will be described below.

[0036] like Figure 1 As shown, some embodiments of this application provide a heat exchange system including a first evaporator 11, a first heat exchanger 12, and a first water storage tank 13. The first evaporator 11 has a first inner cavity 111 for containing water. A first switching valve 112 for controlling air flow is connected to the bottom of the first inner cavity 111, and a first vacuum pump 113 is connected to the top of the first inner cavity 111. A first perforated plate 114 is provided on the wall of the first inner cavity 111 near the first switching valve 112. Air introduced through the first switching valve 112 generates multiple bubbles in the water after passing through the first perforated plate 114. The first vacuum pump 113 extracts the gas from the first inner cavity 111 and brings the pressure in the first inner cavity 111 to a preset condition, causing the water in the first inner cavity 111 to undergo bubble-enhanced evaporation. The first heat exchanger 12 and the first vacuum pump 113... The gas extracted by the first vacuum pump 113 is condensed into liquid water after passing through the first heat exchanger 12. The first water storage tank 13 includes an inlet 131 connected to a water source and an outlet 132 for supplying hot water. The first water storage tank 13 is provided with a first pipe 133 that can exchange heat with the first heat exchanger 12. The water in the first water storage tank 13 is heated by the first heat exchanger 12 and then flows back into the first water storage tank 13. Both the first evaporator 11 and the first water storage tank 13 have a double-layer insulation structure. The material of the first pipe 133 and the material of the first heat exchanger 12 are both insulation materials. The material of the pipe connecting the first evaporator 11 and the first heat exchanger 12 is insulation material.

[0037] Furthermore, the shape and material of the first evaporator 11, the first heat exchanger 12, and the first water storage tank 13 are only required to meet actual needs and are not subject to any restrictions. The first evaporator 11 and the first heat exchanger 12, as well as the first heat exchanger 12 and the first water storage tank 13, are connected via pump pipes. Figure 1 The lines represent pipes, and the arrows indicate the direction of liquid flow, thus allowing the liquid to circulate and exchange heat at the first pipe 133 within the first heat exchanger 12. The first vacuum pump 113 is an oil-free vacuum pump, which can be a piston type, screw type, foil turbine type, magnetic levitation turbine type, or any other type of vacuum pump, as long as it can produce a vacuum level that meets the preset conditions. The water in the first inner cavity 111 evaporates and absorbs heat, causing the water at the lower end of the inner cavity to cool down, which can be used for cooling in summer. At the same time, the high-temperature gas and air mixture after evaporation is drawn away by the first vacuum pump 113 and compressed, then enters the first heat exchanger 12. The high-temperature gas condenses and releases heat, thereby heating the water pumped from the first water storage tank 13 at the first heat exchanger 12. The heated water then flows into the first water storage tank 13, raising the temperature of the water in the first water storage tank 13 to become hot water, which is obtained through the outlet 132 for production and domestic use.

[0038] It should be noted that, as Figure 2As shown, A area in the figure is liquid water, B area is gaseous water, C area is solid water, X point is the triple point, Y point is the boiling point, Z point is the critical point, and XYZ line is the evaporation line. As can be known from the phase diagram of water, the temperature of water at the triple point is 0.01 degrees Celsius, and the pressure is 6.11 mbar; and the temperature of water at the boiling point is 100 degrees Celsius, and the pressure is 1013 mbar. This means that, on the circular arc line between gaseous water and liquid water, i.e., the XYZ line, the liquid water can be evaporated in the range of 0.01 degrees Celsius to 100 degrees Celsius by controlling the pressure of the liquid water. Figure 2

[0039] In actual operation, liquid evaporation is a dynamic process. According to the kinetics theory of liquid evaporation, the formula of the liquid evaporation rate dN / dt is as follows:

[0040]

[0041] In the above formula, ΔP is the pressure difference between the equilibrium pressure of the liquid at temperature T and the actual partial pressure of the gas, N A is Avogadro number, M is molecular weight, R is gas constant, A is the interface area between the liquid phase and the gas phase, exp(-E act / RT) is the probability of the liquid molecules at the interface having enough energy to escape to the gas phase, E act is the activation energy of the evaporation process.

[0042] As can be known from the above formula, to enhance the evaporation rate, the controllable parameters A and ΔP can be increased.

[0043] The first switch valve 112 and the first vacuum pump 113 are arranged in the first evaporator 11 to control the vacuum degree in the first evaporator 11, so as to control the actual partial pressure of the water vapor in the bubbles in the first evaporator 11, and further control ΔP; a certain amount of air is introduced through the first switch valve 112, and a large number of bubbles are formed in the water in the first evaporator 11 after passing through the first porous plate 114, so as to increase the interface area A between the liquid phase and the gas phase. Therefore, the heat exchange system provided in the application controls the vacuum degree in the evaporator by arranging the switch valve and the vacuum pump in the evaporator, and a large number of bubbles are generated by the porous plate, so as to increase the values of the parameters A and ΔP in the above formula, thereby enhancing the evaporation rate of water in the evaporator, starting the bubble-enhanced evaporation mechanism, and realizing the evaporation of water at a preset temperature.

[0044] ​It should be noted that in the heat exchange system of the present application, the air source heat pump water heater uses water as the refrigerant, and in the absence of insulation measures, it is easy to freeze in winter, which determines that it cannot be used in cold areas. Therefore, the first evaporator 11 and the first water tank 13 both adopt a double-layer insulation structure, the material of the first pipe 133 and the material of the first heat exchanger 12 are both insulation materials, and the material of the pipe connecting the first evaporator 11 and the first heat exchanger 12 is also an insulation material, which ensures that the water in the air source heat pump water heater maintains a certain temperature for a certain period of time, so that it can be used in cold areas, and increases the use of air source heat pump water heater. The geographical range. Needless to say, the connecting pipes, pumps and valves of each component in the heat exchange system, as well as the overall shell of the heat exchange system, all need to use insulation materials or external insulation structures.

[0045] The double-layer insulation structure can be composed of a double-layer metal (such as stainless steel 304) or plastic (such as polypropylene, PP) shell, and its vacuum interlayer ensures good insulation in cold seasons. At the same time, the water source uses tap water, which is buried underground by the geothermal effect of the public tap water pipeline in cold areas, to ensure that part of the heat of the system is supplied. The insulation material can be an existing organic or inorganic insulation material. In winter, the water source in the first evaporator 11 can be continuously supplied, and the cold water at the lower end of the first evaporator 11 is promptly discharged from the first inner cavity 111 and promptly supplied with tap water of a certain temperature from the upper end. Due to the use of insulation structure, insulation material and the use of underground heat absorbed by tap water, the heat exchange system can be used in an environment above -5°C, ensuring that each part of the entire heat exchange system does not freeze while meeting the daily demand for hot water. At the same time, in order to make the heat exchange system work in a lower temperature environment, a certain amount of salt can be added to the water.

[0046] The heat exchange system provided by the embodiments of the present application comprises a first evaporator 11 for containing water, the inside of the first evaporator 11 is vacuumized, and air is introduced through a first switch valve 112, a large number of bubbles are generated after the air passes through a first porous plate 114, the contact area between the gas and the liquid water is increased, the evaporation rate of the water is greatly enhanced, and the water in the first evaporator 11 is subjected to bubble-enhanced evaporation. According to the physical principle of heat absorption by evaporation, the heat of the water at the lower end of the first evaporator 11 is absorbed and becomes cold water, and the gas after evaporation passes through the first heat exchanger 12, the absorbed heat is conducted to the water stored in the first water storage tank 13 through the first pipeline 133, the water in the first water storage tank 13 becomes hot water, and the hot water is obtained through the water outlet 132 for daily use. The first evaporator 11 and the first water storage tank 13 are arranged in a double-layer insulation structure, the material of the first pipeline 133, the first heat exchanger 12 and the connecting pipeline is heat insulation material, the heat preservation effect of the whole heat exchange system is increased, the flowability of the refrigerant water is ensured when the air source heat pump type water heater is used in cold regions, and the application region range of the air source heat pump type water heater using water as the refrigerant is expanded.

[0047] In some embodiments of the present application, the heat exchange system further comprises a second water storage tank 14, one end of the second water storage tank 14 is connected to the first evaporator 11, and the other end is connected to the first heat exchanger 12, the second water storage tank 14 is used for providing liquid water to the first evaporator 11 and receiving liquid water condensed by the first heat exchanger 12.

[0048] Further, one end of the second water storage tank 14 is connected to the upper end of the first evaporator 11 through a pipeline and a pump, which is used for providing water to the first evaporator 11, and the other end is connected to the first heat exchanger 12, which is used for collecting water generated after condensation of the first heat exchanger 12. Under the action of the pump, the water flows from the second water storage tank 14 to the first evaporator 11, then to the first heat exchanger 12, and then back to the second water storage tank 14, completing the circulation process of the water in the first evaporator 11 and realizing water saving. On the other hand, the condensed water in the second water storage tank 14 is relatively higher in temperature than the water in the first evaporator 11, and the relatively high hot water after condensation is used again, saving heat and reducing the energy consumption of the whole system. The second water storage tank 14 can be externally connected to a tap water, in winter, the geothermal effect of the public tap water pipeline buried underground in cold regions is used to ensure part of the heat supply of the system. At the same time, the water source of the first evaporator 11 can be continuously supplied, the cold water at the lower end of the first evaporator 11 is discharged from the first inner cavity 111 in time, and the warm water at a certain temperature stored in the second water storage tank 14 is supplied from the upper end of the first evaporator 11 in time.

[0049] In some embodiments of this application, the heat exchange system further includes a second evaporator 15 and a second heat exchanger 16. The second evaporator 15 is provided with a second inner cavity 151 for containing water. The bottom of the second inner cavity 151 is connected to a second switching valve 152 for controlling the air supply. The top of the second inner cavity 151 is connected to a second vacuum pump 153. A second perforated plate 154 is provided on the side of the cavity wall of the second inner cavity 151 near the second switching valve 152. The air introduced by the second switching valve 152 generates multiple bubbles in the water after passing through the second perforated plate 154. The second vacuum pump 153 extracts the gas from the second inner cavity 151 and brings the pressure in the second inner cavity 151 to a preset condition, causing the water in the second inner cavity 151 to undergo bubble-enhanced evaporation. The second heat exchanger 16 is connected to the second vacuum pump 153, and the gaseous water extracted by the second vacuum pump 153 condenses into liquid water after passing through the second heat exchanger 16. The first evaporator 11 is provided with a second pipe 115 that can exchange heat with the second heat exchanger 16. The cold water in the first evaporator 11 is heated by the second heat exchanger 16 and then flows back into the first evaporator 11.

[0050] In other words, the first evaporator 11 is connected in series with a second evaporator 15, which is connected to a second heat exchanger 16, via a second pipe 115. The shape and material of the second evaporator 15 and the second heat exchanger 16 are not limited, as long as they meet practical requirements. The second evaporator 15 and the second heat exchanger 16, as well as the second heat exchanger 16 and the first evaporator 11, are connected via pump pipes. Figure 1 The lines represent pipes, and the arrows indicate the direction of liquid flow, thus facilitating liquid circulation and heat exchange. The second vacuum pump 153 is an oil-free vacuum pump, which can be a piston pump, screw pump, foil turbine pump, magnetic levitation turbine pump, or any other type, as long as it can produce the corresponding vacuum level. The evaporation and heat absorption of the liquid in the second inner cavity 151 cools the fluid at the lower end of the inner cavity. Simultaneously, the high-temperature gas and air mixture after evaporation is drawn away by the second vacuum pump 153 and compressed, then enters the second heat exchanger 16. The high-temperature gas condenses and releases heat, thereby heating the water pumped from the first evaporator 11 at the second heat exchanger 16. The heated water then flows into the first evaporator 11, raising the temperature of the liquid inside the first evaporator 11. After the temperature inside the first evaporator 11 rises, through the heat transfer process of evaporation and heat absorption in the first evaporator 11 and condensation and heat release in the first heat exchanger 12, hot water at a higher temperature (not less than 50 degrees Celsius) is generated in the first water storage tank 13 for production and domestic use.

[0051] In addition, as needed, a third evaporator can be connected in series after the second evaporator 15 via a third heat exchanger, or more evaporators and heat exchangers can be connected in series to provide hot water at a higher temperature. There is no limit to the number of evaporators connected in series.

[0052] In some embodiments of the present application, the heat exchange system further comprises a third water storage tank 17, one end of which is connected to the second evaporator 15 and the other end of which is connected to the second heat exchanger 16, and the third water storage tank 17 is used to provide liquid water to the second evaporator 15 and receive the liquid water condensed by the second heat exchanger 16.

[0053] Further, one end of the third water storage tank 17 is connected to the upper part of the second evaporator 15 through a pipeline and a pump, which is used to provide water to the second evaporator 15, and the other end of the third water storage tank 17 is connected to the second heat exchanger 16, which is used to collect the water condensed by the second heat exchanger 16. Under the action of the pump, the water flows from the third water storage tank 17 to the second evaporator 15, and then to the second heat exchanger 16, and then flows back to the third water storage tank 17, completing the circulation process of the water in the second evaporator 15 and realizing water saving. On the other hand, the condensed water in the third water storage tank 17 is relatively higher in temperature than the original water in the second evaporator 15, and the relatively high hot water after condensation is used again, saving heat and reducing the energy consumption of the entire system.

[0054] In some embodiments of the present application, a water pump 18 is arranged on the path of the third water storage tank 17 to the second evaporator 15, and a third pipeline 19 is arranged on the path of the second evaporator 15 to the third water storage tank 17.

[0055] It should be noted that the water pump 18 arranged on the path of the third water storage tank 17 to the second evaporator 15, on the one hand, in cooperation with other pumps and pipelines, realizes the large circulation of water from the third water storage tank 17 to the second evaporator 15, and then to the second heat exchanger 16, and then flows back to the third water storage tank 17 when the heat exchange system is working in refrigeration or heating mode, and on the other hand, in the case of low temperature, the water pump 18 can be started alone at first, and the hot water flows from the third water storage tank 17 to the second evaporator 15 through the third pipeline 19, and then flows back to the third water storage tank 17, realizing the small circulation of the water, and heating the second evaporator 15, ensuring the normal use of the second evaporator 15 in winter.

[0056] In some embodiments of the present application, the second pipeline 115 and the third pipeline 19 are made of heat preservation material, the pipeline connecting the second evaporator 15 and the second heat exchanger 16 is made of heat preservation material, and the pipeline connecting the first evaporator 11 and the second heat exchanger 16 is made of heat preservation material.

[0057] It should be noted that in order to increase the heat preservation effect of the whole heat exchange system and ensure its use in cold regions, the second pipeline 115 and the third pipeline 19 are both made of heat preservation materials, and the pipelines connecting the second evaporator 15 and the second heat exchanger 16 and the pipelines connecting the first evaporator 11 and the second heat exchanger 16 are both made of heat preservation materials. It is needless to say that the connecting pipelines, pumps and valves of the components in the heat exchange system and the overall shell of the heat exchange system all need to use heat preservation materials or external heat preservation structures. The heat preservation materials can be existing organic or inorganic heat preservation materials that meet the performance requirements. Due to the use of heat preservation structures and heat preservation materials, the heat exchange system can be used in an environment above -5°C, and at the same time, the whole heat exchange system can meet the daily hot water demand without icing.

[0058] In some embodiments of the present application, the second evaporator 15, the second water storage tank 14 and the third water storage tank 17 are all double-layer heat preservation structures.

[0059] It should be noted that the double-layer heat preservation structure can be composed of a double-layer metal (such as stainless steel 304) or plastic (such as polypropylene, PP) shell, and the vacuum interlayer ensures good heat preservation in cold seasons. The water entering the first water storage tank 13, the second water storage tank 14 and the third water storage tank 17 is supplied through a tap water pipe, and at the same time, the geothermal effect of the buried public tap water pipeline underground provides a certain amount of heat for the heat exchange system. It is needless to say that the components in the heat exchange system and their connecting pipelines, pumps and valves, and the overall shell of the heat exchange system all need to use heat preservation materials or external heat preservation structures.

[0060] In some embodiments of the present application, a first exhaust valve 20 is arranged on the path of the liquid water condensed by the first heat exchanger 12 flowing back to the second water storage tank 14; and a second exhaust valve 21 is arranged on the path of the liquid water condensed by the second heat exchanger 16 flowing back to the third water storage tank 17.

[0061] It should be noted that after passing through the first vacuum pump 113, the air is compressed together with the gaseous water, and the gaseous water is condensed into liquid water at the first heat exchanger 12, while the high-pressure air always exists. The first exhaust valve 20 is arranged to discharge the air to the external environment and restore the pressure in the pipeline to normal pressure; on the other hand, if too much air is punched into the first evaporator 11 from the second water storage tank 14, it will reduce the generation of air bubbles in the water in the first evaporator 11, reduce the contact area of the gas phase and the liquid phase, and affect the evaporation rate. The second exhaust valve 21 has the same function as the first exhaust valve 20.

[0062] In some embodiments of the present application, the outer edge of the first porous plate 114 is completely fitted with the inner wall of the first evaporator 11, and the outer edge of the second porous plate 154 is completely fitted with the inner wall of the second evaporator 15.

[0063] From the above analysis, it can be seen that the liquid evaporation rate can be increased by increasing the contact area of the liquid phase and the gas phase. The first porous plate 114 is arranged above the communication position of the first switch valve 112 and the first evaporator 11. The gas entering the first inner cavity 111 through the first switch valve 112 first passes through the first porous plate 114, forms bubbles, and then contacts the water in the first inner cavity 111, thereby further increasing the contact area of the liquid phase and the gas phase and enhancing the evaporation efficiency. The outer edge of the first porous plate 114 is fitted with the inner wall of the first evaporator 11. The air entering from the first switch valve 112 passes through the first porous plate 114, which can increase the number of bubbles and further increase the contact area of the liquid phase and the gas phase, thereby enhancing the evaporation efficiency. The first porous plate 114 is made of metal or plastic, with a thickness of about several millimeters and a diameter of more than 10 centimeters. The first porous plate 114 is provided with a plurality of pores with a pore size of several microns, which can generate more bubbles and increase the contact area of the liquid phase and the gas phase. The second porous plate 154 has the same structure and function as the first porous plate 114.

[0064] In addition, the large number of small bubbles caused by the porous plate disperses the water vapor into each microbubble. The pressure of each microbubble decreases and the volume increases several times during the rising process in the evaporator, resulting in a decrease in the partial pressure of water vapor in each microbubble and a positive ΔP in the above formula, thereby increasing the liquid evaporation rate. The hydrogen bond network and high E act The activation energy of the evaporation process in the above formula, which is about half of the gasification heat of water, will cause the evaporation rate to be slow. The generation of a large number of bubbles caused by the porous plate not only destroys the hydrogen bond network, but also causes high-energy water molecules to have the opportunity to move to the gas-liquid interface and evaporate due to turbulent motion, which has a positive effect on the bubble-enhanced evaporation mechanism.

[0065] In some embodiments of the present application, the cavity wall below the air outlet of the first vacuum pump 113 and the cavity wall below the air outlet of the second vacuum pump 153 are provided with a plurality of baffles 22.

[0066] It should be noted that the baffles 22 are not completely fitted with the inner wall of the evaporator, or the baffles 22 are provided with holes for gas flow. The baffles 22 are arranged to prevent liquid splashing during vacuum pumping. It should be noted that the communication position of the second water tank 14 and the first evaporator 11 should be located below the baffles 22 in the first evaporator 11, and the communication position of the third water tank 17 and the second evaporator 15 should be located below the baffles 22 in the second evaporator 15, so as to avoid the corresponding vacuum pump sucking away the water injected from the water tank.

[0067] In some embodiments of the present application, the baffle 22 in the first evaporator 11 is provided with two pieces and is installed staggered, and the baffle 22 in the second evaporator 15 is provided with two pieces and is installed staggered.

[0068] It should be noted that the baffle 22 is provided with two pieces and is installed staggered, which is a preferred number and installation method of the baffle 22, and the actual number of baffles 22 can be 3, 4 or more, and is installed staggered in layers, and the evaporated gas is sucked away from the gap between the baffles 22 by the vacuum pump. Thus, the suction and splashing of the liquid by the vacuum pump are better avoided.

[0069] In some embodiments of the present application, the first switch valve 112 and the second switch valve 152 are both needle valves.

[0070] It should be noted that the needle valve is a fine adjustment valve, and the valve plug is needle-shaped. The fine adjustment valve requires the valve port to gradually increase from closed to open, and can be continuously and slightly adjusted. The vacuum is created by the vacuum pump, and the amount of air entering is controlled by the needle valve, and the optimal efficiency coefficient of the heat exchange system is further controlled. On the one hand, the amount of air entering the needle valve is controlled to control the number of bubbles, increase the contact area of the liquid and the gas, and thus control the evaporation rate of the water. On the other hand, the size of the vacuum degree is controlled by balancing the air suction of the vacuum pump and the air intake of the needle valve, so as to satisfy the water evaporation under certain temperature and pressure conditions.

[0071] In some embodiments of the present application, the air pressure in the first inner cavity 111 and the second inner cavity 151 is between 150 mbar and 300 mbar.

[0072] It should be noted that the air pressure in the inner cavity is adjusted by the vacuum pump and the switch valve as needed. The lower the air pressure, the greater the vacuum degree, and the easier the liquid water evaporates. The air pressure between 150 mbar and 300 mbar is a preferred pressure range, and does not mean that the heat exchange system does not work under other air pressures.

[0073] In some embodiments of the present application, the heat exchange system further comprises a duct unit 23, the duct unit 23 comprising a fan 231 and a coil pipe 232, the coil pipe 232 being in communication with the second evaporator 15 or the first water storage tank 13, and the low-temperature or high-temperature fluid flowing into the coil pipe 232, the cold air or hot air emitted outside the coil pipe 232 is blown into the environment by the fan 231.

[0074] From the above analysis, the water heat at the lower end of the second evaporator 15 is absorbed and becomes cold water, and the water in the first water tank 13 becomes hot water after heat exchange. The communication of the coil 232 with the second evaporator 15 or the communication of the coil 232 with the first water tank 13 can be controlled by the valve control panel. In summer, the coil 232 is connected with the second evaporator 15, and the cold water in the second evaporator 15 blows out after passing through the coil 232, and the heat exchange system plays a role of air conditioning refrigeration. In addition, the hot water in the first water tank 13 can be used for daily production and life, and the heat exchange system also plays a role of water heater. In winter, the coil 232 is connected with the first water tank 13, and the hot water in the first water tank 13 blows out after passing through the coil 232, and the heat exchange system plays a role of air conditioning heating. It should be noted that in order to ensure the use of the heat exchange system in cold winter, the air pipe unit 23 and the connected pump pipe and valve are made of heat preservation structure or heat preservation material.

[0075] In some embodiments of the present application, the heat exchange system further comprises a first four-way valve 24 and a second four-way valve 25, two ports of the first four-way valve 24 are connected in series on the communication path of the cold water in the second evaporator 15 to the coil 232, and the other two ports of the first four-way valve 24 are connected in series on the communication path of the hot water in the first water tank 13 to the coil 232; two ports of the second four-way valve 25 are arranged on the communication path of the water in the coil 232 to the second evaporator 15, and the other two ports of the second four-way valve 25 are arranged on the communication path of the water in the coil 232 to the first water tank 13.

[0076] That is, the communication of the coil 232 with the second evaporator 15 or the communication of the coil 232 with the first water tank 13 is controlled by the first four-way valve 24 and the second four-way valve 25, the inflow of the coil 232 is controlled by the first four-way valve 24, and the outflow of the coil 232 is controlled by the second four-way valve 25. In summer, two ports in the first four-way valve 24, which are in series in the communication path of the cold water in the second evaporator 15 to the coil 232, are opened, and two ports in the second four-way valve 25, which are arranged in the communication path of the water in the coil 232 to the second evaporator 15, are opened, so that the coil 232 communicates with the second evaporator 15, and the cold water in the second evaporator 15 blows out cold air after passing through the coil 232, and the heat exchange system plays a role of air conditioning refrigeration. In winter, the other two ports in the first four-way valve 24, which are in series in the communication path of the hot water in the first water tank 13 to the coil 232, are opened, and the other two ports in the second four-way valve 25, which are arranged in the communication path of the water in the coil 232 to the first water tank 13, are opened, so that the coil 232 communicates with the first water tank 13, and the hot water in the first water tank 13 blows out hot air after passing through the coil 232, and the heat exchange system plays a role of air conditioning heating. It should be noted that, in order to ensure that the heat exchange system can be used in cold winter above -5℃, the first four-way valve 24, the second four-way valve 25, and the connected pump pipe and valve are made of heat preservation structure or heat preservation material.

[0077] In addition, the existing water-based air conditioner and water heater technology seals the evaporator, the expansion valve, the condenser, and the turbine compressor in a vacuum housing, and uses an external vacuum pump to maintain the operating pressure at 25 millibars. It is large in size, difficult to maintain, and only suitable for large facilities such as data centers, and is not suitable for independent air conditioning and water heaters in residential and commercial buildings. The air conditioner and water heater technology provided by the present application uses bubble-enhanced evaporation technology, only needs to maintain a certain vacuum for the evaporator, and does not need a vacuum housing, greatly reducing the size of the equipment, and is suitable for independent air conditioning and water heaters in residential and commercial buildings.

[0078] Those skilled in the art can understand that the above embodiments are specific examples of the present application, and in actual application, various changes can be made in form and details without departing from the spirit and scope of the present application.

Claims

1. A heat exchange system, characterized by, The application relates to a water heating device, which comprises the following parts: a first evaporator, which is provided with a first inner cavity containing water, the bottom of the first inner cavity is connected with a first switch valve for controlling air inflow, the top of the first inner cavity is connected with a first vacuum pump, the cavity wall of the first inner cavity is provided with a first porous plate near the side of the first switch valve, air inflowing through the first switch valve generates a plurality of bubbles in water after passing through the first porous plate, the first vacuum pump extracts gas in the first inner cavity and makes the pressure in the first inner cavity reach a preset condition, bubble-enhanced evaporation phenomenon occurs in water in the first inner cavity; a first heat exchanger, which is connected with the first vacuum pump, gas extracted by the first vacuum pump is condensed into liquid water after passing through the first heat exchanger; a first water storage tank, which comprises a water inlet connected with a water source and a water outlet for supplying hot water, the first water storage tank is provided with a first pipeline capable of exchanging heat with the first heat exchanger, water in the first water storage tank is heated by the first heat exchanger and then flows back into the first water storage tank; the first evaporator and the first water storage tank are both double-layer heat preservation structures, the material of the first pipeline and the material of the first heat exchanger are both heat preservation materials, and the material of the pipeline connected between the first evaporator and the first heat exchanger is a heat preservation material.

2. A heat exchange system according to claim 1, wherein The water heating device further comprises a second water storage tank, one end of the second water storage tank is connected with the first evaporator, and the other end of the second water storage tank is connected with the first heat exchanger, the second water storage tank is used for providing liquid water to the first evaporator and receiving liquid water condensed by the first heat exchanger.

3. A heat exchange system according to claim 1, wherein The water heating device further comprises a second evaporator and a second heat exchanger, the second evaporator is provided with a second inner cavity containing water, the bottom of the second inner cavity is connected with a second switch valve for controlling air inflow, the top of the second inner cavity is connected with a second vacuum pump, the cavity wall of the second inner cavity is provided with a second porous plate near the side of the second switch valve, air inflowing through the second switch valve generates a plurality of bubbles in water after passing through the second porous plate, the second vacuum pump extracts gas in the second inner cavity and makes the pressure in the second inner cavity reach a preset condition, bubble-enhanced evaporation phenomenon occurs in water in the second inner cavity; the second heat exchanger is connected with the second vacuum pump, gaseous water extracted by the second vacuum pump is condensed into liquid water after passing through the second heat exchanger; the first evaporator is provided with a second pipeline capable of exchanging heat with the second heat exchanger, cold water in the first evaporator is heated by the second heat exchanger and then flows back into the first evaporator.

4. A heat exchange system according to claim 3, wherein The water heating device further comprises a third water storage tank, one end of the third water storage tank is connected with the second evaporator, and the other end of the third water storage tank is connected with the second heat exchanger, the third water storage tank is used for providing liquid water to the second evaporator and receiving liquid water condensed by the second heat exchanger.

5. A heat exchange system according to claim 4, wherein A water pump is arranged on the path of the third water storage tank flowing to the second evaporator, and a third pipeline is arranged on the path of the second evaporator flowing to the third water storage tank.

6. A heat exchange system according to claim 5, wherein The material of the second pipeline and the material of the third pipeline are both heat preservation materials, the material of the pipeline connected between the second evaporator and the second heat exchanger is a heat preservation material, and the material of the pipeline connected between the first evaporator and the second heat exchanger is a heat preservation material.

7. A heat exchange system according to claim 4, wherein The second evaporator, the second water storage tank and the third water storage tank are double-layer insulation structures.

8. A heat exchange system according to claim 4, wherein A first exhaust valve is arranged on a path of the liquid water condensed by the first heat exchanger and flowing back to the second water storage tank; and a second exhaust valve is arranged on a path of the liquid water condensed by the second heat exchanger and flowing back to the third water storage tank.

9. A heat exchange system according to claim 3, wherein The outer edge of the first porous plate is completely attached to the inner wall of the first evaporator, and the outer edge of the second porous plate is completely attached to the inner wall of the second evaporator.

10. A heat exchange system according to claim 3, wherein The cavity wall below the air outlet of the first vacuum pump and the cavity wall below the air outlet of the second vacuum pump are respectively provided with a plurality of baffles.

11. A heat exchange system according to claim 10, wherein The baffles in the first evaporator are provided with two baffles and are installed staggered, and the baffles in the second evaporator are provided with two baffles and are installed staggered.

12. A heat exchange system according to claim 3, wherein The first switch valve and the second switch valve are needle valves.

13. A heat exchange system according to claim 3, wherein The air pressure in the first inner cavity and the second inner cavity is between 150 mbar and 300 mbar.

14. A heat exchange system according to claim 3, wherein The air pipe unit includes a fan and a coil pipe, the coil pipe is communicated with the second evaporator or the first water storage tank, and after the low-temperature or high-temperature fluid flows into the coil pipe, the cold air or hot air emitted outside the coil pipe is blown to the environment by the fan.

15. A heat exchange system according to claim 14, wherein The first four-way valve and the second four-way valve are further included, two ports of the first four-way valve are connected in series on a communication path of the cold water in the second evaporator to the coil pipe, the other two ports of the first four-way valve are connected in series on a communication path of the hot water in the first water storage tank to the coil pipe, two ports of the second four-way valve are arranged on a communication path of the water in the coil pipe to the second evaporator, and the other two ports of the second four-way valve are arranged on a communication path of the water in the coil pipe to the first water storage tank.

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