CN210532739U - Heat pump system with phase change energy tower - Google Patents

Abstract

The utility model relates to the field of air conditioner heat exchange, in particular to a heat pump system with a phase change energy tower, which comprises a phase change energy tower and a refrigerant circulating closed loop; a phase change energy tower comprising a tower body; the inside of the tower body is provided with a heat exchange tube and a spraying system which adopts a phase change medium as a fluid; the spraying system comprises a sprayer which is arranged above the heat exchange tube and the spraying direction of which faces the heat exchange tube, and a liquid storage tank which is arranged below the heat exchange tube and used for bearing the phase change medium; the liquid storage tank is communicated with the sprayer through a pipeline, and the phase change medium sprayed by the sprayer exchanges heat with the refrigerant in the air exchange tube in a partial evaporation or condensation mode on the surface of the air exchange tube. The phase-change energy tower in the heat pump system uses a phase-change medium as a secondary refrigerant, and a refrigerant is conveyed through a closed circulation loop, so that a phase-change heat exchange scheme is adopted in the closed refrigerant circulation loop, the heat exchange effect is improved, and the system operation cost is reduced.

Description

Heat pump system with phase change energy tower

Technical Field

The utility model relates to an air conditioner heat transfer field especially relates to a heat pump system with phase transition energy tower.

Background

With the high-speed increase of Chinese economy, the energy consumption is larger and larger, the ecological environment is destroyed by a large amount of fossil fuels, and the greenhouse effect is more and more serious. The building energy consumption of China is huge at present, and the proportion of the building energy consumption to the terminal energy consumption of the whole society of China is about 27.5 percent at present. Along with the development of urbanization, the building energy consumption is rapidly increased, and the development of urbanization causes great pressure on energy supply of building energy in China. The air conditioning energy consumption is about 30% of the building energy consumption, and the improvement of the efficiency of an air conditioning system has great significance for energy conservation and emission reduction.

In hot summer and cold winter areas of China, as the areas are not heated in a centralized manner in winter, most buildings are heated by adopting electric or auxiliary-heating air source heat pumps, oil-fired boilers, gas-fired boilers and other modes, and the problems of high-grade energy consumption, low primary energy utilization rate, pollution and the like exist. Meanwhile, due to the characteristics of low temperature and high humidity of outdoor air in winter in hot-summer and cold-winter areas, the outdoor heat exchanger of the air source heat pump system which is used more in the areas at present is difficult to maintain to operate under a dry working condition, water vapor in the air is condensed on the surfaces of fins, and various performance coefficients of the system are greatly reduced after frosting occurs, and even the system cannot work. Aiming at the climate characteristics of the region, the novel heat pump system of the heat source tower heat pump is developed and developed by combining the advantages of the air source heat pump and the cooling tower for the water cooling unit and utilizing the sensible heat of the humid air and the latent heat of the phase change of the water vapor in winter for solving the problem of frosting of the outdoor heat exchanger. The heat source tower is used as a cooling tower to discharge heat to the environment in summer, and is used as a heat source tower to absorb heat in the air by using the low-temperature antifreezing solution in winter. The equipment has the characteristics of double high efficiency in winter and summer, the utilization rate of the equipment is improved by using one tower, and the equipment is energy-saving and environment-friendly.

The heat source tower heat pump overcomes the defects of the traditional water-cooling water chilling unit and boiler system that the cooling tower is idle in winter and the boiler is polluted, also avoids the problem of frosting like an air source heat pump, and has the manufacturing cost and the maintenance cost far lower than that of a water-ground source heat pump system. However, due to the difference of operating conditions in winter and summer, heat dissipation of the heat source tower mainly depends on latent heat, sensible heat in heat exchange capacity of the heat source tower in winter is large in occupied ratio and the latent heat is small in occupied ratio, and heat exchange efficiency of the heat source tower in winter is lower than that of the heat source tower in summer, so that the heat source tower is generally designed according to the working conditions in winter, and the designed heat source tower is large in size. The larger volume of the heat source tower increases the cost of the heat source tower and is prone to site limitation. Meanwhile, the building loads are different under different outdoor conditions, the heat source tower heat pump is mainly used in the middle and lower reaches of the Yangtze river at present, and the advantages of the heat source tower are not obvious in the areas with lower air temperature in winter. This is because the building load and the amount of heat taken by the heat source tower are contradictory, and the building heat load is large when the outdoor air temperature is low, but at this time, it becomes difficult for the heat source tower to take heat from the outdoor air. In this situation, more heat is extracted from the outdoor environment, which necessitates lowering the temperature of the circulating solution in the heat source tower and increasing the temperature differential to extract more heat. As the solution temperature decreases, it will result in a decrease in vaporization temperature and a decrease in system energy efficiency. Therefore, the heat source tower has certain limitation on the outdoor environment temperature in winter, and when the environment temperature is too low, the heat taken by the heat source tower with the same volume will be attenuated, so that the heat required by the building can not be met. Therefore, the applicable area of the heat source tower at present is mainly the middle and lower reaches of the Yangtze river, and the use of the heat source tower is limited in cold areas.

Therefore, how to improve the heat extraction amount of the heat source tower at low ambient temperature, reduce the volume of the heat source tower, improve the application range and efficiency of the heat source tower, and solve the problem of large occupied area of the heat source tower becomes a technical problem which needs to be solved urgently by technical personnel in the field.

For example, chinese patent publication No. CN109798615A discloses a cross-flow type heat source tower based on a phase change microcapsule solution, and belongs to the technical field of refrigeration and air conditioning. The heat source tower body is connected with a cooling tower fluid pipeline; an air inlet is formed in the outer side wall of the heat source tower body; a heat exchange cavity is arranged in the heat source tower body, and the air inlet is communicated with the heat exchange cavity; the center of the heat exchange cavity of the heat source tower body is a central through hole cavity penetrating through the upper part and the lower part of the heat source tower body; PVC filler which absorbs heat from air is filled in the heat exchange cavity, and the PVC filler is phase-change microcapsule solution; the top of the heat exchange cavity is communicated with a liquid inlet pipeline of cooling tower fluid; the bottom end of the heat source tower body is communicated with a liquid outlet pipeline of the cooling tower; liquid enters the filler part in the heat exchange cavity from the liquid inlet pipeline and flows back to the cooling tower from the liquid outlet pipeline at the bottom end of the heat source tower body. The utility model discloses well phase change microcapsule solution phase change material can take place the phase transition at whereabouts in-process, and consequently its specific heat capacity is great, and solution heat absorption after the temperature will remain unchanged or the range of variation is very little. The technical scheme shows that phase change heat exchange is applied in the heat source tower at present, and regarding the phase change heat exchange, the vaporization latent heat of water under normal pressure is more than 500 times of the specific heat capacity of the water, and the solidification latent heat of the water is nearly 80 times of the specific heat capacity of the water, so that the heat exchange quantity can be greatly improved by utilizing the phase change, and the circulation quantity of a heat exchange medium is reduced. But the disadvantage of the proposal is that the microcapsule solution adopted in the spraying system of the proposal is taken as the circulating medium, and the phase-change microcapsule solution can generate phase change after the microcapsule solution is fully subjected to heat and mass exchange with air in the filler. Although the phase-change microcapsule solution is a novel working medium integrating heat storage and enhanced heat transfer characteristics compared with the common solution, the potential safety hazard exists when the microcapsule solution is applied to a heat pump system. In addition, in the scheme of the prior application, the phase-change microcapsule solution adopts a spraying open type heat exchange mode, certain problems exist when the microcapsule solution is applied to a heat pump system loop, such as impurities and dust problems caused by open type heat exchange, and the operating cost of an open type heat source tower is high.

For example, a heat source tower adopting a phase change mode to exchange heat with air is described in the chinese utility model patent with the publication number "CN 207439195U", which comprises a tower frame and a hot wall heat exchanger, wherein an axial flow fan is arranged at the upper part of the tower frame; the hot wall heat exchanger comprises an air heat exchange assembly and a non-frozen liquid fluid heat exchange assembly, the air heat exchange assembly is arranged in the tower frame and comprises an upper communicating pipe, a lower communicating pipe, a first heat exchange wall and a heating device, the upper communicating pipe and the lower communicating pipe are communicated through the first heat exchange wall, and the lower communicating pipe of the air heat exchange assembly is connected with the heating device; the unfrozen liquid fluid heat exchange assembly comprises an unfrozen liquid heat exchange container and a second heat exchange wall, wherein two ends of the second heat exchange wall are respectively connected to the upper communicating pipe and the lower communicating pipe; one end of the unfrozen liquid heat exchange container is provided with a liquid inlet of the unfrozen liquid, and the other end of the unfrozen liquid heat exchange container is provided with a liquid outlet of the unfrozen liquid. The utility model discloses a heat source tower can low energy consumption, low cost and timely defrosting. When the refrigeration function is realized in summer, the heat source tower of the scheme can be used as a water cooling tower, the spraying circulating pump starts to work at the moment, and the spraying circulating pump does not need to work in winter, which is completely different from the existing closed heat source tower. During refrigeration, water is sprayed to the air heat exchange assembly through the spray header, a water film is formed on the surface of the first heat exchange wall, and under the action of high negative pressure, the water film is evaporated after absorbing latent heat of phase-change fluid (refrigerant) in the first heat exchange wall, so that the phase-change fluid is condensed into liquid. The phase-change fluid which is changed into liquid flows to a second heat exchange wall in the unfrozen liquid fluid heat exchange assembly through the lower communicating pipe to absorb latent heat of the unfrozen liquid and then is evaporated, and the evaporated phase-change fluid flows into the air heat exchange assembly through the upper communicating pipe to exchange heat with air and a water film outside the air heat exchange assembly. In the scheme, the final temperature of the unfrozen liquid after cooling is lower than that of a conventional open heat source tower (cooling tower), the closed phase-change long-distance heat exchange heat source tower can ensure that heat transfer is never influenced by the biological slime thermal resistance of the open cooling tower, and the operating cost of the closed heat source tower heat pump system is far lower than that of an open heat source tower heat pump system and a cooling tower refrigeration system due to the factors. But in the scheme, the refrigerant is selected as the phase-change fluid, and the spraying circulating pump does not need to work in winter.

A compound integrated heat source tower heat pump device is described in a Chinese invention patent publication with an authorization publication number of CN103438613B, and a winter and summer double high-efficiency heat source tower for realizing solution regeneration by using solar energy and a heat exchange method are described in the Chinese invention patent publication with the authorization publication number of CN 105698352B. Both of the above patent documents describe solutions for exchanging heat with the refrigerant in the heat exchanger tubes by means of a sprinkler system, but the solutions are not combined with phase change heat exchange.

Disclosure of Invention

In order to solve the above problem, a first object of the present invention is to provide a heat pump system with a phase-change energy tower, wherein the phase-change energy tower in the heat pump system uses a phase-change medium as a secondary refrigerant, and a refrigerant is transported through a closed circulation loop, so as to adopt a phase-change heat exchange scheme in the refrigerant circulation closed loop, thereby improving the heat exchange effect and reducing the operation cost of the system.

A second object of the present invention is to provide a heat exchanging method of the heat pump system.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

a heat pump system with a phase-change energy tower comprises the phase-change energy tower and a refrigerant circulation closed loop; a phase change energy tower comprising a tower body; the inside of the tower body is provided with a heat exchange tube and a spraying system which adopts a phase change medium as a fluid; the heat exchange tube is connected in a refrigerant circulation closed loop, the refrigerant circulation closed loop also comprises a heat exchanger, and the heat exchange direction of the refrigerant in the heat exchanger is opposite to that of the refrigerant in the heat exchange tube of the phase-change energy tower; the spraying system comprises a sprayer which is arranged above the heat exchange tube and the spraying direction of which faces the heat exchange tube, and a liquid storage tank which is arranged below the heat exchange tube and used for bearing the phase change medium; the liquid storage tank is communicated with the sprayer through a pipeline, and the phase change medium sprayed by the sprayer exchanges heat with the refrigerant in the air exchange tube in a partial evaporation or condensation mode on the surface of the air exchange tube.

The above technical scheme is adopted in the utility model, this technical scheme relates to a heat pump system with phase change energy tower, what adopt in the spraying system is phase change medium in this phase change energy tower, the phase change medium that spraying system sprayed can be attached to heat exchange tube surface formation water film or thin ice, and carry out the heat exchange with the inside refrigerant of heat exchange tube with the mode of partial evaporation or condensation, the latent heat of vaporization of water is 500 multifold of water specific heat capacity under the ordinary pressure, the latent heat of solidification of water is nearly 80 times of water specific heat capacity, so utilize the phase transition can greatly improve the heat transfer volume. Compared with the scheme described in the patent text with the publication number of CN109798615A, the scheme does not use a phase change medium as a medium in a heat pump circulating system, only uses the phase change medium as a secondary refrigerant, and conveys the refrigerant through a closed circulating loop, so that the phase change heat exchange scheme is adopted in the closed loop of the refrigerant circulation, the heat exchange effect is improved, and the system operation cost is reduced. The Chinese utility model patent scheme with publication number "CN 207439195U" selects the refrigerant as the phase-change fluid, the quality of the phase-change fluid is not much, the heating temperature rising block can strive for more time for heating; however, the scheme is essentially different from the scheme that the phase change medium is used as the refrigerating medium.

Preferably, one end of the heat exchange tube is a liquid inlet and outlet end, and the other end of the heat exchange tube is a gas inlet and outlet end; the refrigerant circulating closed loop also comprises a compressor, a throttling device and an oil separator, wherein the compressor, the oil separator, the gas inlet and outlet ends of the heat exchange tube, the liquid inlet and outlet ends of the heat exchange tube, the throttling device, the liquid inlet end of the heat exchanger, the gas inlet and outlet ends of the heat exchanger and the compressor are sequentially connected to form a first heat exchange loop; the compressor, the oil separator, the air inlet and outlet ends of the heat exchanger, the liquid outlet end of the heat exchanger, the throttling device, the liquid inlet and outlet ends of the heat exchange tube, the air inlet and outlet ends of the heat exchange tube and the compressor are sequentially connected to form a second heat exchange loop. This embodiment is particularly an embodiment of a heat pump system into which the phase change energy tower is incorporated.

Preferably, an air inlet is formed in the lower end portion of the tower body, an air outlet is formed in the top of the tower body, and a fan for promoting air flow from the air inlet to the air outlet is arranged in the tower body. In this technical scheme, the inside refrigerant of heat exchange tube can carry out the heat exchange with the inside air of tower body (but the exclusive use air heat transfer, does not open spraying system this moment), and the setting up of above-mentioned air intake, air outlet and fan can promote inside circulation of air, promotes heat exchange efficiency.

Preferably, the filler is arranged in the tower body between the lower part of the heat exchange tube and the air inlet, and the filler can enable air and the phase change medium to exchange heat for the second time; the fan is arranged on the air inlet of the tower body, and a demister is arranged inside the tower body between the fan and the heat exchange tube.

Preferably, the heat exchange tubes are spiral coils, and two axially adjacent layers of coil units in the spiral coils are arranged in a staggered manner; the liquid inlet and outlet ends of the spiral coil pipe are provided with distributors, the distributors are connected with each liquid inlet and outlet end of the heat exchange pipe, the liquid inlet and outlet pipe is provided with a one-way valve, and the flow direction of the liquid inlet and outlet pipe is opposite to that of the distributors. In the scheme, the spiral coil is adopted for the purpose of reducing the pressure of the medium in the pipe; generally, the pressure drop in the pipe is generally composed of two parts, namely, the on-way resistance and the local resistance, and the local resistance coefficient will usually be several times the on-way resistance coefficient. According to the traditional multi-flow tube row arrangement mode, when media flow in the tubes, the flow is changed, the direction needs to be changed by 180 degrees, so that local resistance is increased once in each turning, the total pressure drop is increased, the spiral tubes are basically along-the-way resistance, the local resistance can be ignored, and the total pressure drop of the media in the tubes can be reduced. Further, the two layers of axially adjacent coil units are arranged in a staggered mode, namely the upper layer coil unit and the lower layer coil unit are arranged in a staggered mode, and the coils of the lower layer coil unit are located between the two coils of the upper layer coil unit. The reason is that the traditional calandria arrangement is straight, namely the upper calandria and the lower calandria are aligned, water is sprayed onto the calandria from the upper part, some water cannot be sprayed onto the tubes due to gaps among the calandria to cause insufficient spraying, and in addition, the lower wind also has a part to be short-circuited from the calandria to cause insufficient heat exchange between the wind and the tubes. The staggered arrangement that this scheme adopted, medium, fluid on the coil pipe of upper coil pipe unit can be along the pipe surface drip to the coil pipe of lower floor's coil pipe unit on, so all water can spray on the pipe, spray like this fully, in addition, the wind that comes on the bottom can not the short circuit, and wind produces the vortex through crisscross pipe moreover, has strengthened the heat transfer effect of wind side. In addition, the distributor has the advantages that the distributor is adopted, distribution is more uniform, and the heat exchange coefficient is higher.

Preferably, at least a first temperature sensor for measuring the surface temperature of the coil, a second temperature sensor for measuring the temperature of the phase change medium in the liquid storage tank and a third temperature sensor for detecting the air temperature at the air inlet are arranged in the tower body. The detection data provided by the first temperature sensor, the second temperature sensor and the third temperature sensor is used for monitoring the operation of the heat source tower in the scheme.

Preferably, an auxiliary heating device is arranged in the liquid storage tank and used for auxiliary heating when the ambient temperature is particularly low.

When a refrigerant in a refrigerant circulation closed loop flows through a heat exchanger tube, a spraying system sprays a phase change medium in a liquid storage tank onto the surface of the heat exchange tube through a sprayer and exchanges heat with the refrigerant in an air exchange tube in a partial evaporation or condensation mode; so as to liquefy or gasify the refrigerant in the heat exchange tubes.

Preferably, a summer mode and a winter mode are included;

summer mode: refrigerant gas is compressed by a compressor and then enters an oil separator for oil separation, and then the refrigerant gas enters the gas inlet and outlet end of a heat exchange tube of the phase change energy tower; the spraying system operates to spray the phase change medium to the surface of the heat exchange tube through the sprayer, the phase change medium forms a water film on the surface of the heat exchange tube and absorbs heat through a partial evaporation method, and the refrigerant in the air exchange tube releases heat to be liquefied; the liquefied refrigerant enters the heat exchanger to be evaporated into gas after being throttled by the throttling device, and then flows to the compressor to complete the circulation of the first loop;

winter mode: refrigerant gas is compressed by a compressor and then enters an oil separator for oil separation, then enters a heat exchange tube to be condensed into liquid, the refrigerant liquid enters a liquid inlet and outlet end of the heat exchange tube after being throttled by a throttling device, and the temperature of the refrigerant liquid is lower than the solidification temperature of a phase change medium; the spraying system operates to spray a phase change medium onto the surface of the heat exchange tube through the sprayer, the phase change medium forms thin ice on the surface of the heat exchange tube and releases heat in a partial condensation mode, and a refrigerant in the ventilation tube absorbs the heat to be gasified and is finally discharged through the gas inlet and outlet end of the heat exchange tube; the refrigerant gas is discharged and flows to the compressor, completing the second loop cycle.

Preferably, in winter mode;

setting unit time T, and monitoring the difference change of the solution temperature and the surface temperature of the coil; when the temperature of the surface of the coil pipe and the difference value of the freezing points of the corresponding solutions are reduced to a set value, the flow of the spraying system is increased, and the thin ice on the surface of the coil pipe is flushed and enters the liquid storage tank to be melted into liquid; when the difference between the temperature of the surface of the coil pipe and the freezing point of the corresponding solution is reduced to a set value, the flow of the spraying system is adjusted back to be normal.

Preferably, in winter mode;

an online solution hydrometer is arranged in the liquid storage tank, and when ice slurry begins to be generated on the surface of the coil pipe, certain ice slurry can be accumulated in the solution tank; when the specific gravity of the solution is larger than a set value, the flow of the spraying system is increased, and the thin ice on the surface of the coil pipe is flushed and enters the liquid storage tank to be melted into liquid; and when the specific gravity of the solution is smaller than a set value, the flow of the spraying system is adjusted back to be normal.

The two schemes are mainly characterized in that the flow of the spraying system is controlled through different detection data, and the thin ice on the surface of the coil is flushed into the liquid storage tank through the flow increasing mode of the spraying system.

By integrating all the structures, the phase change energy tower has the following advantages:

1. the spiral coil pipes are arranged in a vertically staggered manner, so that the resistance of a refrigerant in the pipe is smaller, the spraying heat exchange outside the pipe is more sufficient, and the total heat transfer coefficient is higher;

2. the heat exchange coil is not provided with fins, so that the problems of corrosion and scaling caused by long-term operation are avoided, and the operation is maintenance-free;

3. the heat exchanger is used as evaporative cooling to absorb heat through latent heat of water evaporation in summer, and is used as a heat source tower to absorb latent heat of water condensation and even freezing in winter, so that latent heat of water-saving phase change in different seasons is fully utilized, and the efficiency of the heat exchanger is higher;

4. when the heat source tower is used as a heat source tower, the refrigerant inlet adopts the distributor, the distribution is more uniform, the heat exchange is higher, and when the heat source tower is used as evaporation cold in summer, the distributor is bypassed by the one-way valve;

5. the filler is positioned below the coil pipe, and the air and the solution exchange heat secondarily and the heat exchange is sufficient;

6. the refrigerant directly enters the heat source tower to exchange heat with the solution, so that the intermediate heat exchange temperature difference is reduced, and the system efficiency is higher;

7. compared with the traditional air cooling unit, the coiled pipe cannot frost in winter, the operation efficiency is improved, and the use of a user cannot be influenced;

8. the mode is switched according to seasonal environment change and use conditions, so that energy is saved;

9. and a closed structure is adopted, so that little floating water is generated, and the water consumption is reduced.

Drawings

Fig. 1 is a schematic view of a phase change energy tower related to the present invention.

Fig. 2 is a schematic diagram of a heat pump system having a phase change energy tower operating in a summer mode.

Fig. 3 is a schematic diagram of a heat pump system having a phase change energy tower operating in a winter mode.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining the present invention, and should not be construed as limiting the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and to simplify the description, but do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, unless otherwise specified, "a plurality" means two or more unless explicitly defined otherwise.

In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the present disclosure, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact between the first and second features, or may comprise contact between the first and second features not directly. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

Example 1:

a heat pump system with a phase change energy tower as shown in figures 1-3 comprises a phase change energy tower 1 and a refrigerant circulating closed loop; the refrigerant circulation closed loop comprises a heat exchange tube 11 arranged in the phase change energy tower 1, one end of the heat exchange tube 11 is a liquid inlet and outlet end, and the other end of the heat exchange tube is a gas inlet and outlet end. The refrigerant circulation closed circuit further includes a heat exchanger 21, a compressor 22, a throttle 23, and an oil separator 24. The compressor 22, the oil separator 24, the air inlet and outlet ends of the heat exchange tube 11, the liquid inlet and outlet ends of the heat exchange tube 11, the throttling device 23, the liquid inlet end of the heat exchanger 21, the air inlet and outlet ends of the heat exchanger 21 and the compressor 22 are sequentially connected to form a first heat exchange loop, namely a summer heat exchange loop. The compressor 22, the oil separator 24, the air inlet and outlet ends of the heat exchanger 21, the liquid outlet end of the heat exchanger 21, the throttling device 23, the liquid inlet and outlet ends of the heat exchange tube 11, the air inlet and outlet ends of the heat exchange tube 11 and the compressor 22 are sequentially connected to form a second heat exchange loop, namely a winter heat exchange loop. As shown in particular in fig. 1, the heat exchanger 21 is a shell and tube heat exchanger 21, preferably a falling film heat exchanger 21; the refrigerant circulation closed circuit further comprises a four-way valve 25, a liquid storage tank 26 and four check valves 27, and as shown in the figure, four ends of the four-way valve 25 are respectively connected to the output end of the oil separator 24, the gas inlet and outlet ends of the heat exchange pipe 11, the gas inlet and outlet ends of the heat exchanger 21 and the input end of the compressor 22. The liquid outlet end of the heat exchanger 21 and the liquid inlet and outlet ends of the heat exchange tube 11 are respectively connected with the input end of the liquid storage tank 26 through pipelines, and each pipeline is provided with a one-way valve 27; the output end of the liquid storage tank 26 is connected with the liquid inlet and outlet ends of the heat exchange tube 11 and the liquid inlet end of the heat exchanger 21 through pipelines respectively, and each pipeline is provided with a one-way valve 27.

The phase change energy tower 1 comprises a tower body 12. The inside of the tower body 12 is provided with a heat exchange tube 11 for hermetically conveying a refrigerant and a spraying system adopting a phase change medium as a fluid. The spraying system comprises a sprayer 13 which is arranged above the heat exchange tube 11 and the spraying direction of which faces the heat exchange tube 11, and a liquid storage tank 14 which is arranged below the heat exchange tube 11 and is used for bearing the phase change medium. The liquid storage tank 14 is communicated with the sprayer 13 through a pipeline, a solution pump 15 is arranged on the pipeline and used for supplying power to the phase change medium conveyed to the sprayer 13 from the liquid storage tank 14, a liquid level meter 16 and a liquid supplementing channel 17 are arranged on the liquid storage tank 14, and when the liquid level meter 16 monitors that the phase change medium in the liquid storage tank 14 is lower than a set height, the phase change medium is supplemented through the liquid supplementing channel 17. In addition, an auxiliary heating device is arranged in the liquid storage tank 14 to assist in heating when the ambient temperature is particularly low, so that the phase change medium is prevented from being solidified in the liquid storage tank 14. In a specific embodiment, the auxiliary heating device is a desuperheating heat exchanger 3, and as shown in the figure, the desuperheating heat exchanger 3 is positioned in the liquid storage tank 14; when the heat pump operates, the exhaust pipe of the compressor passes through the heat source tower solution tank, on one hand, overheating is removed, the efficiency of a heat pump system is improved, on the other hand, the solution tank is heated, the temperature of the solution is improved, and the efficiency of the heat source tower and the ice melting speed are improved.

The heat exchange tubes 11 are spiral coils, and axially adjacent two layers of coil units in the spiral coils are arranged in a staggered mode. One end of the spiral coil pipe is a liquid inlet and outlet end, and the other end of the spiral coil pipe is a gas inlet and outlet end. The liquid inlet and outlet ends of the spiral coil pipe are provided with distributors 18, and the distributors 18 are connected with each liquid inlet and outlet end of the heat exchange pipe 11. In the above scheme, the purpose of using the spiral coil is to reduce the pressure of the medium in the pipe. Generally, the pressure drop in the pipe is generally composed of two parts, namely, the on-way resistance and the local resistance, and the local resistance coefficient will usually be several times the on-way resistance coefficient. According to the traditional multi-flow tube row arrangement mode, when media flow in the tubes, the flow is changed, the direction needs to be changed by 180 degrees, so that local resistance is increased once in each turning, the total pressure drop is increased, the spiral tubes are basically along-the-way resistance, the local resistance can be ignored, and the total pressure drop of the media in the tubes can be reduced. Further, the two layers of axially adjacent coil units are arranged in a staggered mode, namely the upper layer coil unit and the lower layer coil unit are arranged in a staggered mode, and the coils of the lower layer coil unit are located between the two coils of the upper layer coil unit. The reason is that the traditional calandria arrangement is straight, namely the upper calandria and the lower calandria are aligned, water is sprayed onto the calandria from the upper part, some water cannot be sprayed onto the tubes due to gaps among the calandria to cause insufficient spraying, and in addition, the lower wind also has a part to be short-circuited from the calandria to cause insufficient heat exchange between the wind and the tubes. The staggered arrangement that this scheme adopted, medium, fluid on the coil pipe of upper coil pipe unit can be along the pipe surface drip to the coil pipe of lower floor's coil pipe unit on, so all water can spray on the pipe, spray like this fully, in addition, the wind that comes on the bottom can not the short circuit, and wind produces the vortex through crisscross pipe moreover, has strengthened the heat transfer effect of wind side. In addition, the distributor 18 has the functions that the distributor 18 is adopted, the distribution is more uniform, and the heat exchange coefficient is higher.

An air inlet is formed in the lower end portion of the tower body 12, an air inlet grille 19 is arranged on the air inlet, an air outlet is formed in the top of the tower body 12, and a fan 10 promoting air flow from the air inlet to the air outlet is arranged in the tower body 12. In this technical scheme, the inside refrigerant of heat exchange tube 11 can carry out the heat exchange with the inside air of tower body 12, and the setting of above-mentioned air intake, air outlet and fan 10 can promote inside circulation of air, promotes heat exchange efficiency. In a further preferred scheme, a filler 101 is arranged inside the tower body 12 between the lower part of the heat exchange tube 11 and the air inlet, and the filler 101 can enable air and a phase change medium to exchange heat secondarily. The fan 10 is positioned at an air inlet of the tower body 12, and a demister 102 is arranged inside the tower body 12 between the fan 10 and the heat exchange tube 11. On the basis of the scheme, the filler 101 is arranged below the heat exchange tube 11, so that secondary heat exchange between air and solution is facilitated, and the heat exchange is sufficient.

In the above scheme, at least a first temperature sensor for measuring the surface temperature of the coil pipe, a second temperature sensor for measuring the temperature of the phase change medium in the liquid storage tank 14, and a third temperature sensor for detecting the air temperature at the air inlet are arranged in the tower body 12. The detection data provided by the first temperature sensor, the second temperature sensor and the third temperature sensor are used for monitoring the operation of the heat source tower in the scheme, namely, the ambient temperature and the use load are judged by detecting the temperature of the phase change medium, the temperature of the coil pipe of the heat exchanger 21 and the temperature of the inlet air. The refrigerant in the heat exchange tube 11 exchanges heat with the air in the tower body 12, and the phase change medium of the sprayer 13 exchanges heat, which can be adjusted in different modes according to the ambient temperature and the use load, including but not limited to the following modes:

when the ambient temperature is relatively low, such as in an excessive season, even when the ambient temperature is lower than the indoor temperature, but the indoor needs to be cooled: at this time, the system can be switched to the natural cooling mode, the compressor 22 is not turned on, and the heat source tower fan 10 has two modes of turning on and turning off according to the condensing temperature.

And secondly, when the ambient temperature in summer is lower, the heat source tower fan 10 has an on mode and an off mode according to the condensation temperature, and when the heat source tower fan 10 is turned on, the solution pump 15 also has an on mode and an off mode according to the condensation temperature.

Thirdly, when the ambient temperature is higher in summer; the heat source tower fan 10 operates at the strongest gear and is operated according to the rated frequency and the frequency increasing operation mode of the condensation temperature solution pump 15 to improve the efficiency of the system.

Fourthly, when the environmental temperature is very low in winter; the heat source tower fan 10 operates at the strongest gear and can have an ice slurry phase-change heat exchange mode and an auxiliary heat exchange mode.

Fifthly, when the environmental temperature is lower in winter; the heat source tower fan 10 can operate in a water vapor condensation phase-change heat exchange mode and an ice slurry phase-change heat exchange mode.

Sixthly, when the environmental temperature is higher in winter; the heat source tower fan 10 has two modes of on and off according to the evaporation temperature, and the solution pump 15 has two modes of on and off when the heat source tower fan 10 is turned on.

In the above-described embodiment, the phase change medium sprayed from the sprayer 13 exchanges heat with the refrigerant inside the air-exchanging pipe by partially evaporating or condensing the phase change medium on the surface of the air-exchanging pipe. The phase-change medium adopted by the scheme can be an alcohol solution such as ethylene glycol or propylene glycol or a salt solution such as a sodium chloride mixed solution, and the concentration of the solution can be adjusted according to the lowest operating environment temperature to change the freezing point, so that the phase-change energy tower is suitable for the natural environment of the area where the phase-change energy tower is located. The technical scheme relates to a phase change energy tower 1, wherein a phase change medium is adopted in a spraying system in the phase change energy tower 1, the phase change medium sprayed by the spraying system can be attached to the surface of a heat exchange tube 11 to form a water film or thin ice, and exchanges heat with a refrigerant inside the heat exchange tube 11 in a partial evaporation or condensation mode, the vaporization latent heat of water under normal pressure is more than 500 times of the specific heat capacity of the water, and the solidification latent heat of the water is more than 80 times of the specific heat capacity of the water, so that the heat exchange quantity can be greatly improved by utilizing phase change. Compared with the scheme described in the patent document with the publication number of CN109798615A, the scheme does not use a phase change medium as a medium in a heat pump circulating system, only uses the phase change medium as a secondary refrigerant, and conveys the refrigerant through a closed circulating loop, so that the phase change heat exchange scheme is adopted in a closed energy tower, the heat exchange effect is improved, and the system operation cost is reduced. The patent scheme of the Chinese utility model with the publication number of CN207439195U is that the refrigerant is selected as the phase-change fluid, the quality of the phase-change fluid is not much, and more time can be won for heating by heating the temperature rising block. However, the scheme is essentially different from the scheme that the phase change medium is used as the refrigerating medium.

By integrating all the structures, the phase change energy tower 1 has the following advantages:

1. the spiral coil pipes are arranged in a vertically staggered manner, so that the resistance of the refrigerant in the pipe is smaller, the spraying heat exchange outside the pipe is more sufficient, and the total heat transfer coefficient is higher.

2. The heat exchange coil is not provided with fins, so that the problems of corrosion and scaling caused by long-term operation are avoided, and the operation is maintenance-free;

3. the heat exchanger 21 absorbs heat through latent heat of water evaporation in summer as evaporative cooling, absorbs latent heat of water condensation and even freezing as a heat source tower in winter, fully utilizes latent heat of water-saving phase change in different seasons, and is higher in efficiency.

4. When the heat source tower is used, the distributor 18 is adopted at the refrigerant inlet, the distribution is more uniform, the heat exchange is higher, and when the heat source tower is used as evaporation cold in summer, the distributor 18 is bypassed through the one-way valve 27.

5. The filler 101 is positioned below the coil pipe, and the air and the solution exchange heat for the second time, so that the heat exchange is sufficient.

6. The refrigerant directly enters the heat source tower to exchange heat with the solution, so that the intermediate heat exchange temperature difference is reduced, and the system efficiency is higher.

7. Compared with the traditional air cooling unit, the coiled pipe cannot frost in winter, the operation efficiency is improved, and the use of a user cannot be influenced.

8. And multiple modes are switched according to seasonal environment change and use conditions, so that more energy is saved.

9. And a closed structure is adopted, so that little floating water is generated, and the water consumption is reduced.

Example 2:

this embodiment is a heat exchange method based on the heat pump system having the phase change energy tower 1 in embodiment 1, and therefore this embodiment is implemented by using the heat pump system in embodiment 1 described above. In particular, the embodiment relates to a heat exchange method of a heat pump system with a phase change energy tower 1, when the refrigerant in a refrigerant circulation closed loop flows through the heat exchanger 21, the spraying system sprays the phase change medium in a liquid storage tank 14 onto the surface of the heat exchange pipe 11 through a sprayer 13 and exchanges heat with the refrigerant in the inside of a ventilation pipe in a partially evaporating or condensing manner; so that the refrigerant inside the heat exchange pipe 11 is liquefied or vaporized.

The heat exchange method comprises a summer mode and a winter mode.

Summer mode (as shown in fig. 2): refrigerant gas is compressed by a compressor 22 and then enters an oil separator 24 for oil separation, and then enters the gas inlet and outlet ends of a heat exchange tube 11 of the phase change energy tower 1; the spraying system operates, the phase change medium is sprayed to the surface of the heat exchange tube 11 through the sprayer 13, the phase change medium forms a water film on the surface of the heat exchange tube 11, heat is absorbed through a partial evaporation method, and the refrigerant in the air exchange tube releases heat to be liquefied; the liquefied refrigerant enters the heat exchanger 21 to be evaporated into gas after being throttled by the throttling device 23, and then flows to the compressor 22 to complete the first loop cycle;

winter mode (as shown in fig. 3): refrigerant gas is compressed by the compressor 22 and then enters the oil separator 24 for oil separation, then enters the heat exchange tube 11 to be condensed into liquid, the refrigerant liquid enters the liquid inlet and outlet ends of the heat exchange tube 11 after being throttled by the throttling device 23, and the temperature of the refrigerant liquid is lower than the solidification temperature of the phase change medium; the spraying system operates to spray a phase change medium to the surface of the heat exchange tube 11 through the sprayer 13, the phase change medium forms thin ice on the surface of the heat exchange tube 11 and releases heat in a partial condensation mode, and a refrigerant in the ventilation tube absorbs the heat to be gasified and is finally discharged through the gas inlet and outlet end of the heat exchange tube 11; the refrigerant gas is discharged and flows to the compressor 22, completing the second circuit cycle.

Compare in present energy tower heat transfer scheme, this scheme and prior art's the most main difference lies in winter phase transition heat transfer, and heat transfer spiral coil pipe is felt as the evaporimeter winter, and double-phase refrigerant passes through distributor 18 entering dish, and cold medium matter can evenly distributed, improves heat exchange efficiency on the one hand like this, and on the other hand coil pipe surface heat transfer is even also does benefit to phase transition heat transfer's control. There are two ways of phase change in winter, which can occur simultaneously. The first mode is that water vapor in the air is condensed into water due to the reduction of the air temperature, and the heat is released to exchange heat with the air and the coil pipe. In another mode, part of the circulating solution is made into ice slurry, and water is solidified into ice to release heat, so that the heat exchange quantity and the heat exchange efficiency can be greatly improved in a short time.

There are two assumptions about the specific control method using ice slurried circulating solution phase change media: one is through the temperature, to a solution of certain concentration corresponds a freezing point temperature T ice, when the coolant medium temperature is lower than this freezing point temperature in the coil pipe, can let the solution freeze, through measuring the temperature T pipe on the coil pipe surface, when T pipe is less than T ice-0.5 ℃ (this temperature value can be regulated and set up), monitor coolant medium temperature and coil pipe heat transfer heat in the coil pipe, if the coolant temperature has short instant rising in the coil pipe and the coil pipe heat transfer volume obviously enlarges, it shows that the solution has already begun to freeze on the coil pipe surface at this moment, set a time T, then carry on integral control to this time T, through monitoring the difference change of solution temperature and coil pipe surface temperature, when the integral value is accumulated to the set value such as 360 ℃ for a second, increase solution pump 15 frequency, use the ice slurry of the large water flush coil pipe surface, because increase the flowrate, improved the heat transfer of solution and coil pipe and air at the same time, the temperature of the refrigerant medium and the air can be increased, because the flushed ice slurry is melted into solution and enters the solution tank again, when the difference between the temperature of the surface of the coil pipe and the freezing point of the corresponding solution is reduced to a set value, the solution pump 15 is lowered to normal operation frequency, and therefore an ice slurry phase-change heat exchange cycle is completed.

Another control method is that an on-line solution specific gravity meter is arranged in the solution tank, when ice slurry is generated on the surface of the coil pipe, certain ice slurry is accumulated in the solution tank, the specific gravity of the solution changes, the specific gravity change value can be set by monitoring the specific gravity change value, for example, when the specific gravity increase value exceeds 5%, the value can be set, the frequency of the solution pump is adjusted, and when the specific gravity returns to normal, for example, the specific gravity change value is less than 2%, the value can be set, and the frequency of the solution pump is reduced to normal.

The two schemes are mainly characterized in that the flow of the spraying system is controlled through different detection data, and the thin ice on the surface of the coil is flushed into the liquid storage tank 14 through the flow increasing mode of the spraying system.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although embodiments of the present invention have been shown and described, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that changes, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art without departing from the principles and spirit of the present invention.

Claims (7)

1. A heat pump system with a phase-change energy tower comprises the phase-change energy tower (1) and a refrigerant circulation closed loop; the method is characterized in that: the phase change energy tower (1) comprises a tower body (12); a heat exchange tube (11) and a spraying system adopting a phase change medium as a fluid are arranged in the tower body (12); the heat exchange tube (11) is connected in a refrigerant circulation closed loop, the refrigerant circulation closed loop further comprises a heat exchanger (21), and the heat exchange direction of refrigerant in the heat exchanger (21) is opposite to that in the heat exchange tube (11) of the phase change energy tower; the spraying system comprises a sprayer (13) which is arranged above the heat exchange tube (11) and the spraying direction of which faces the heat exchange tube (11), and a liquid storage tank (14) which is arranged below the heat exchange tube (11) and used for bearing the phase change medium; the liquid storage tank (14) is communicated with the sprayer (13) through a pipeline, and the phase change medium sprayed by the sprayer (13) exchanges heat with the refrigerant in the air exchange tube in a partial evaporation or condensation mode on the surface of the air exchange tube.

2. The heat pump system with the phase-change energy tower as claimed in claim 1, wherein: one end of the heat exchange tube (11) is a liquid inlet and outlet end, and the other end of the heat exchange tube is a gas inlet and outlet end; the refrigerant circulating closed loop further comprises a compressor (22), a throttling device (23) and an oil separator (24), wherein the compressor (22), the oil separator (24), the gas inlet and outlet ends of the heat exchange tube (11), the liquid inlet and outlet ends of the heat exchange tube (11), the throttling device (23), the liquid inlet end of the heat exchanger (21), the gas inlet and outlet end of the heat exchanger (21) and the compressor (22) are sequentially connected to form a first heat exchange loop; the compressor (22), the oil separator (24), the air inlet and outlet end of the heat exchanger (21), the liquid outlet end of the heat exchanger (21), the throttling device (23), the liquid inlet and outlet end of the heat exchange tube (11), the air inlet and outlet end of the heat exchange tube (11) and the compressor (22) are sequentially connected to form a second heat exchange loop.

3. A heat pump system with a phase change energy tower according to claim 1 or 2, wherein: the air inlet is arranged at the lower end of the tower body (12), the air outlet is arranged at the top of the tower body (12), and the fan (10) for promoting air flow from the air inlet to the air outlet is arranged in the tower body (12).

4. The heat pump system with the phase-change energy tower as claimed in claim 3, wherein: a filler (101) is arranged inside the tower body (12) between the lower part of the heat exchange tube (11) and the air inlet, and the filler (101) can enable air and a phase change medium to exchange heat for the second time; the fan (10) is positioned on an air inlet of the tower body (12), and a demister (102) is arranged inside the tower body (12) between the fan (10) and the heat exchange tube (11).

5. A heat pump system with a phase change energy tower according to claim 1 or 2, wherein: the heat exchange tubes (11) are spiral coil tubes, and axially adjacent coil tube units in the spiral coil tubes are arranged in a staggered mode; the liquid inlet and outlet ends of the spiral coil pipe are provided with distributors (18), the distributors (18) are connected with each liquid inlet and outlet end of the heat exchange pipe (11), the liquid inlet and outlet pipe is provided with a one-way valve, and the flow direction of the liquid inlet and outlet pipe is opposite to that of the distributors (18).

6. A heat pump system with a phase change energy tower according to claim 1 or 2, wherein: the tower body (12) is at least internally provided with a first temperature sensor for measuring the surface temperature of the coil pipe, a second temperature sensor for measuring the temperature of the phase-change medium in the liquid storage tank (14) and a third temperature sensor for detecting the temperature of air at the air inlet.

7. A heat pump system with a phase change energy tower according to claim 1 or 2, wherein: an auxiliary heating device is arranged in the liquid storage tank (14) and used for auxiliary heating when the ambient temperature is particularly low.

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