Energy Tower Heat Pump System

Abstract

The present invention provides an energy tower heat pump system, comprising: a spray tower, a liquid pipeline, a first heat exchanger, a second heat exchanger, a first fan, a first temperature sensor, a second temperature sensor and a controller; the first heat exchanger and the second heat exchanger constitute a refrigerant circuit, and the liquid pipeline transports the liquid at the bottom of the spray tower to the top of the spray tower so that the liquid contacts the first heat exchanger in the spray tower; the spray tower is provided with an air inlet and an air outlet, and the first temperature sensor is arranged at the air inlet for detecting the air inlet temperature of the air inlet; the first fan and the second temperature sensor are both arranged at the air outlet, and the second temperature sensor is used to detect the air outlet temperature of the air outlet; the controller determines a first temperature difference according to the air inlet temperature and the air outlet temperature, and controls the operating frequency of the first fan according to the comparison result between the first temperature difference and the first target temperature difference. The energy tower heat pump system of the present invention has low operating cost, high heat exchange efficiency and high reliability.

Description

Technical Field

[0001] The invention relates to the technical field of heating equipment, and in particular to an energy tower heat pump system. Background Art

[0002] In recent years, building energy consumption has shown a significant growth trend. Energy tower heat pumps can be widely used in the field of building air conditioning due to their many advantages such as high efficiency and energy saving, wide operating range in low temperature areas, anti-frost, usable in all seasons, and not restricted by geographical conditions. They can achieve heating in winter, cooling in summer, and domestic hot water throughout the year, gradually replacing water source heat pumps, ground source heat pumps, air source heat pumps, and electric / oil / coal-fired boilers. Energy tower heat pump technology is applied to the field of building heating, with huge market space and broad development prospects.

[0003] In order to cope with the low temperature and high humidity climate environment in the south in winter, the energy tower heat pump system, as a cold and hot source solution for the central air-conditioning system, can obtain low-grade heat in the atmosphere at an ambient temperature below zero degrees, realize the heating function and operate stably. The energy tower spray solution absorbs the sensible heat of the air and the latent heat of water vapor in the atmosphere to provide a heat source for the water source heat pump unit, thereby meeting the heating needs of the building. The latent heat of water vapor accounts for approximately 10% to 30% of the total air energy.

[0004] When the existing energy tower heat pump system operates in a low temperature and high humidity environment, the spray solution will continuously absorb water vapor in the atmosphere and dilute itself. The freezing point of the diluted spray solution drops, which makes the energy tower heat pump system face the risk of shutdown and affects the stable operation of the system. The spray solution needs to be regenerated to maintain the concentration of the spray solution within a certain range, which causes the energy tower system to face the problem of spray solution regeneration, and the process is long, energy consumption is high, and there is a risk of shutdown. Summary of the invention

[0005] The present invention provides an energy tower heat pump system to solve the defects of the existing energy tower heat pump system, which needs to maintain the concentration of the spray solution by a concentrated regeneration method or a reagent addition method, resulting in high energy consumption, high operating cost and low reliability.

[0006] The present invention provides an energy tower heat pump system, comprising: a spray tower, a liquid pipeline, a first heat exchanger, a second heat exchanger, a first fan, a first temperature sensor, a second temperature sensor and a controller;

[0007] The first heat exchanger is disposed in the spray tower, the first heat exchanger and the second heat exchanger form a refrigerant circuit, and the liquid pipeline can transport the liquid at the bottom of the spray tower to the top of the spray tower, so that the liquid contacts the first heat exchanger;

[0008] An air inlet is provided at the bottom of the spray tower, and an air outlet is provided at the top of the spray tower. The first temperature sensor is provided at the air inlet and is used to detect the air inlet temperature of the air inlet. The first fan and the second temperature sensor are both provided at the air outlet, and the second temperature sensor is used to detect the air outlet temperature of the air outlet.

[0009] The controller determines a first temperature difference between the inlet air temperature and the outlet air temperature according to the inlet air temperature and the outlet air temperature, and controls the operating frequency of the first fan according to a comparison result between the first temperature difference and a first target temperature difference.

[0010] According to an energy tower heat pump system provided by the present invention, the energy tower heat pump system further comprises a humidity sensor, the humidity sensor is arranged at the air inlet, and is used to detect the air humidity of the air inlet;

[0011] The controller determines the first target temperature difference according to the inlet air humidity.

[0012] According to an energy tower heat pump system provided by the present invention, the first target temperature difference is 2-5°C.

[0013] According to an energy tower heat pump system provided by the present invention, the liquid pipeline includes a first circulation pump and a spray assembly;

[0014] The spray assembly is arranged between the first heat exchanger and the first fan, one end of the first circulation pump is connected to the bottom of the spray tower, and the other end of the first circulation pump is connected to the spray assembly.

[0015] According to an energy tower heat pump system provided by the present invention, the energy tower heat pump system further includes a third temperature sensor and a fourth temperature sensor;

[0016] The third temperature sensor is disposed at the bottom of the spray tower to detect the temperature of the liquid, and the fourth temperature sensor is disposed at the first heat exchanger to detect the evaporation temperature of the refrigerant;

[0017] The controller determines a second temperature difference between the temperature of the liquid and the evaporation temperature of the refrigerant according to the temperature of the liquid and the evaporation temperature of the refrigerant, and controls the operation frequency of the first circulation pump according to a comparison result between the second temperature difference and a second target temperature difference.

[0018] According to an energy tower heat pump system provided by the present invention, the second target temperature difference is 3-5°C.

[0019] According to an energy tower heat pump system provided by the present invention, the energy tower heat pump system also includes a concentrating device, the concentrating device includes a liquid storage tank and an ice chamber, the liquid storage tank is connected to the ice chamber, the liquid storage tank is used to store fluid, and the ice chamber is used to concentrate the liquid.

[0020] According to an energy tower heat pump system provided by the present invention, the energy tower heat pump system further comprises a fifth temperature sensor, the fifth temperature sensor being used to detect the temperature in the freezing chamber;

[0021] The controller controls the flow rate of the fluid according to a comparison result between the temperature in the freezing chamber and a target temperature.

[0022] According to an energy tower heat pump system provided by the present invention, the energy tower heat pump system further comprises a density sensor, which is arranged at the bottom of the spray tower and is used to detect the density of the liquid;

[0023] The controller controls activation or deactivation of the concentrating device according to a comparison result between the density of the liquid and a target density.

[0024] According to an energy tower heat pump system provided by the present invention, the energy tower heat pump system further includes a third heat exchanger and a second circulation pump;

[0025] One end of the second circulation pump is connected to the second heat exchanger, and the other end of the second circulation pump is connected to the third heat exchanger.

[0026] The energy tower heat pump system provided by the present invention has a liquid pipeline that transports the liquid at the bottom of the spray tower to the top of the spray tower. The liquid fully exchanges heat with the air during the descent process. The liquid is evenly distributed on the surface of the first heat exchanger. The liquid exchanges heat with the refrigerant in the first heat exchanger to complete the transfer of heat from the air to the liquid, and further from the liquid to the refrigerant. The controller controls the operating frequency of the first fan so that the first temperature difference is within the range of the first target temperature difference, thereby ensuring that the concentration of the liquid is maintained within a reasonable range, ensuring the stable operation of the energy tower heat pump system, low operating cost, high heat exchange efficiency, and high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1It is a structural schematic diagram of the energy tower heat pump system provided by the present invention;

[0029] Reference numerals:

[0030] 1: Spray tower; 2: First fan;

[0031] 3: The first circulation pump; 4: Spray assembly;

[0032] 5: first heat exchanger; 6: compressor;

[0033] 7: first temperature sensor; 8: first humidity sensor;

[0034] 9: second temperature sensor; 10: second humidity sensor;

[0035] 11: the third temperature sensor; 12: density sensor;

[0036] 13: fourth temperature sensor; 14: liquid storage tank;

[0037] 15: Second valve; 16: Ice chamber;

[0038] 17: The third valve; 18: The fourth valve;

[0039] 19: fifth temperature sensor; 20: first valve;

[0040] 21: The fifth valve; 22: The second fan;

[0041] 23: the sixth valve; 24: the second heat exchanger;

[0042] 25: The second circulation pump; 26: The third heat exchanger. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] Combine the following Figure 1 An energy tower heat pump system according to an embodiment of the present invention is described.

[0046] like Figure 1 As shown, the energy tower heat pump system provided by the embodiment of the present invention includes: a spray tower 1, a liquid pipeline, a first heat exchanger 5, a second heat exchanger 24, a first fan 2, a first temperature sensor 7, a second temperature sensor 9 and a controller.

[0047] The first heat exchanger 5 is disposed in the spray tower 1 . The first heat exchanger 5 and the second heat exchanger 24 form a refrigerant circuit. The liquid pipeline can transport the liquid at the bottom of the spray tower 1 to the top of the spray tower 1 so that the liquid contacts the first heat exchanger 5 .

[0048] An air inlet is provided at the bottom of the spray tower 1, and an air outlet is provided at the top of the spray tower 1. The first temperature sensor 7 is provided at the air inlet for detecting the air inlet temperature of the air inlet; the first fan 2 and the second temperature sensor 9 are both provided at the air outlet, and the second temperature sensor 9 is used to detect the air outlet temperature of the air outlet.

[0049] The controller determines a first temperature difference between the inlet air temperature and the outlet air temperature according to the inlet air temperature and the outlet air temperature, and controls the operating frequency of the first fan 2 according to a comparison result between the first temperature difference and a first target temperature difference.

[0050] Specifically, an air inlet is provided at the bottom of the spray tower 1, and the air inlet is arranged along the circumferential direction of the spray tower 1. The number and size of the air inlet are set according to actual needs. An air outlet is provided at the top of the spray tower 1. The first fan 2 drives the outside air into the spray tower 1 along the air inlet, and the air moves from bottom to top in the spray tower 1. The spray tower 1 contains a liquid for heat exchange with the air. The liquid pipeline transports the liquid at the bottom of the spray tower 1 to the top of the spray tower 1, and the liquid falls from the top of the spray tower 1, and the liquid moves from top to bottom in the spray tower 1.

[0051] The liquid moves from top to bottom in the spray tower 1, and the air moves from bottom to top in the spray tower 1. The liquid and the air perform sufficient heat exchange in the spray tower 1, and the heat of the air is transferred to the liquid. The liquid forms a uniform film on the surface of the first heat exchanger 5 during the falling process. The tube side of the first heat exchanger 5 is filled with refrigerant. The heat of the air absorbed by the liquid is further transferred to the refrigerant in the tube side. The refrigerant absorbs the heat of the liquid and evaporates.

[0052] The refrigerant circuit is provided with a compressor 6 and a sixth valve 23. The sixth valve 23 is an expansion valve. The high-temperature and high-pressure gaseous refrigerant compressed by the compressor 6 enters the second heat exchanger 24, and is converted into a liquid refrigerant after condensing and releasing heat in the second heat exchanger 24. The liquid refrigerant flows into the first heat exchanger 5 along the pipeline. The liquid refrigerant flowing into the first heat exchanger 5 absorbs the heat of the liquid on the surface of the first heat exchanger 5, and the above compression cycle process is repeated.

[0053] The first heat exchanger 5 is a shell and tube heat exchanger, preferably a double-pass or four-pass heat exchanger, with a heat exchange tube diameter preferably between 20 and 32 mm and a heat exchange area preferably between 120 and 150 m 2 between.

[0054] The first heat exchanger 5 serves as a gas-liquid heat and mass exchange site between liquid and air, and also serves as an evaporator of the refrigerant. Through countercurrent heat and mass exchange and convection heat transfer, it realizes the transfer of air heat to liquid, and further to the refrigerant, ultimately realizing the transfer and utilization of heat.

[0055] During the heat exchange process between liquid and air, if the liquid absorbs water vapor in the air, it will be diluted. The freezing point of the diluted liquid will drop, which will affect the stable operation of the entire system. Therefore, the concentration of the liquid needs to be controlled so that it is maintained within a reasonable range.

[0056] Specifically, the first temperature sensor 7, the second temperature sensor 9 and the first fan 2 are all communicatively connected to the controller. The first temperature sensor 7 detects the inlet air temperature of the air inlet, and the second temperature sensor 9 detects the outlet air temperature of the air outlet. The controller calculates a first temperature difference between the inlet air temperature and the outlet air temperature, and controls the operating frequency of the first fan 2 according to a comparison result between the first temperature difference and the first target temperature difference. By controlling the operating frequency of the first fan 2 to make the first temperature difference consistent with the first target temperature difference, it is ensured that the liquid will not be diluted or concentrated during the heat exchange process.

[0057] The first target temperature difference is 2 to 5°C. The first target temperature difference is related to the external environment. For example, during the day, when the external environment temperature is high and the relative humidity is low, the first target temperature difference is 5°C. If the first temperature difference is lower than 5°C, it indicates that the heat exchange between the liquid and the air needs to be reduced, and the controller reduces the operating frequency of the first fan 2; if the first temperature difference is higher than 5°C, it indicates that the heat exchange between the liquid and the air needs to be increased, and the controller increases the operating frequency of the first fan 2. By controlling the operating frequency of the first fan 2, the first temperature difference is consistent with the first target temperature difference, thereby ensuring that the concentration of the liquid is maintained within a reasonable range.

[0058] For example, at night the external ambient temperature is low and the relative humidity is high, and the first target temperature difference is 2°C. If the first temperature difference is lower than 2°C, it indicates that the heat exchange between the liquid and the air needs to be reduced, and the controller reduces the operating frequency of the first fan 2; if the first temperature difference is higher than 2°C, it indicates that the heat exchange between the liquid and the air needs to be increased, and the controller increases the operating frequency of the first fan 2.

[0059] The controller controls the operating frequency of the first fan 2 so that the first temperature difference is within the range of the first target temperature difference, thereby ensuring that the concentration of the liquid is maintained within a reasonable range, thereby ensuring the stable operation of the energy tower heat pump system.

[0060] In addition, the outlet air temperature needs to be controlled above the inlet air dew point temperature. If the outlet air temperature is lower than the inlet air dew point temperature, part of the air in the spray tower 1 will liquefy and dilute the liquid. If the outlet air temperature detected by the second temperature sensor 9 is lower than the inlet air dew point temperature, the controller should increase the operating frequency of the first fan 2 and increase the heat exchange so that the outlet air temperature is greater than the inlet air dew point temperature to prevent the liquid from being diluted.

[0061] In the embodiment of the present invention, the liquid pipeline transports the liquid at the bottom of the spray tower 1 to the top of the spray tower 1. The liquid fully exchanges heat with the air during the falling process. The liquid is evenly distributed on the surface of the first heat exchanger 5. The liquid exchanges heat with the refrigerant in the first heat exchanger 5 to complete the transfer of heat from the air to the liquid, and further from the liquid to the refrigerant. The controller controls the operating frequency of the first fan 2 so that the first temperature difference is within the range of the first target temperature difference, thereby ensuring that the concentration of the liquid is maintained within a reasonable range, ensuring the stable operation of the energy tower heat pump system, low operating cost, high heat exchange efficiency, and high reliability.

[0062] In an optional embodiment, the energy tower heat pump system also includes a humidity sensor, which is arranged at the air inlet and is used to detect the inlet air humidity of the air inlet. The controller determines the first target temperature difference according to the inlet air humidity.

[0063] like Figure 1As shown, the air inlet is provided with a first humidity sensor 8, which is used to detect the air humidity of the air inlet, and the air outlet is provided with a second humidity sensor 10, which is used to detect the air humidity of the air outlet. The first humidity sensor 8 and the second humidity sensor 10 are connected to the controller for communication. When the air humidity is greater than the humidity balance point of the liquid, the liquid will absorb moisture in the air and the liquid will gradually be diluted; when the air humidity is less than the humidity balance point of the liquid, the air will absorb moisture in the liquid and the liquid will gradually be concentrated. The air humidity has a very important influence on the concentration of the liquid.

[0064] The first target temperature difference is determined according to the inlet air humidity so that the absolute humidity content of the inlet air and the outlet air remains unchanged.

[0065] The ambient temperature and ambient relative humidity are known. The ambient temperature is equivalent to the temperature of the air entering the spray tower 1 along the air inlet, the ambient temperature is equivalent to the inlet temperature of the air inlet, and the ambient relative humidity is equivalent to the inlet humidity. The ambient relative humidity changes at the same ambient temperature. For different ambient relative humidities, the first target temperature difference is also different.

[0066] The relationship between the ambient temperature, ambient relative humidity and the first target temperature difference is shown in Table 1. Table 1 is a parameter table of the ambient temperature, ambient relative humidity and the first target temperature difference.

[0067] Table 1 Parameters of ambient temperature, ambient relative humidity and first target temperature difference

[0068]

[0069] As shown in Table 1, for example, when the ambient temperature is 5°C and the relative humidity is 87%, the first target temperature difference is 2°C, that is, the air inlet temperature at the air inlet is 5°C, and the air outlet temperature at the air outlet should be 3°C. For example, when the ambient temperature is 5°C and the relative humidity is 75%, the first target temperature difference is 4°C, that is, the air inlet temperature at the air inlet is 5°C, and the air outlet temperature at the air outlet should be 1°C.

[0070] In an embodiment of the present invention, the first target temperature difference is determined by the inlet air humidity and the inlet air temperature, and the controller further controls the outlet air temperature of the air outlet by controlling the operating frequency of the first fan 2, so that the first temperature difference is consistent with the first target temperature difference, thereby ensuring that the concentration of the liquid is maintained within a reasonable range.

[0071] like Figure 1 As shown, in an optional embodiment, the liquid pipeline includes a first circulation pump 3 and a spray assembly 4.

[0072] The spray assembly 4 is arranged between the first heat exchanger 5 and the first fan 2 , one end of the first circulation pump 3 is connected to the bottom of the spray tower 1 , and the other end of the first circulation pump 3 is connected to the spray assembly 4 .

[0073] Specifically, the first heat exchanger 5, the spray assembly 4 and the first fan 2 are arranged in sequence in the spray tower 1 along the height direction of the spray tower 1. One port of the first circulation pump 3 is connected to the bottom of the spray tower 1 through a pipeline, and the other port of the first circulation pump 3 is connected to the spray assembly 4 through a pipeline. A first valve 20 is provided between the first circulation pump 3 and the spray assembly 4. The first circulation pump 3 drives the liquid that drops to the bottom of the spray tower 1 to return to the spray assembly 4 along the pipeline through the first valve 20, and is evenly sprayed by the spray assembly 4. The liquid moves from top to bottom in the spray tower 1.

[0074] After being uniformly sprayed out from the spray assembly 4 , the liquid moves from top to bottom in the spray tower 1 , and the air moves from bottom to top in the spray tower 1 . The liquid and the air perform sufficient countercurrent heat transfer in the spray tower 1 .

[0075] After the liquid falls to the bottom of the spray tower 1, it is transported to the spray assembly 4 through the first circulation pump 3, and then evenly sprayed out by the spray assembly 4 to continue to exchange heat with the air entering the spray tower 1 from the outside. The liquid that falls on the surface of the first heat exchanger 5 transfers the heat of the air to the refrigerant in the first heat exchanger 5, thereby repeating the above-mentioned spray cycle heat exchange process.

[0076] In the embodiment of the present invention, the first circulation pump 3 and the spray assembly 4 drive the liquid to reciprocate and circulate in the spray tower 1 to perform sufficient heat exchange with the air, which is beneficial to improving the heat exchange efficiency.

[0077] like Figure 1 As shown, in an optional embodiment, the energy tower heat pump system also includes a third temperature sensor 11 and a fourth temperature sensor 13 .

[0078] The third temperature sensor 11 is provided at the bottom of the spray tower 1 to detect the temperature of the liquid, and the fourth temperature sensor 13 is provided at the first heat exchanger 5 to detect the evaporation temperature of the refrigerant;

[0079] The controller determines a second temperature difference between the temperature of the liquid and the evaporation temperature of the refrigerant according to the temperature of the liquid and the evaporation temperature of the refrigerant, and controls the operation frequency of the first circulation pump 3 according to a comparison result between the second temperature difference and a second target temperature difference.

[0080] Specifically, the third temperature sensor 11, the fourth temperature sensor 13 and the first circulation pump 3 are communicatively connected to the controller. The controller calculates the second temperature difference between the temperature of the liquid and the evaporation temperature of the refrigerant, and controls the operating frequency of the first circulation pump 3 according to the comparison result between the second temperature difference and the second target temperature difference. By controlling the operating frequency of the first circulation pump 3 so that the second temperature difference is within the range of the second target temperature difference, it is ensured that the liquid will not be diluted or concentrated during the heat exchange process.

[0081] The range of the second target temperature difference is 3-5°C. If the second temperature difference is greater than 5°C, it indicates that the heat exchange between the liquid and the refrigerant needs to be strengthened, and the controller increases the operating frequency of the first circulation pump 3; if the second temperature difference is less than 3°C, it indicates that the heat exchange between the liquid and the refrigerant needs to be weakened, and the controller reduces the operating frequency of the first circulation pump 3. By controlling the operating frequency of the first circulation pump 3, the first temperature difference is within the range of the first target temperature difference, thereby ensuring that the concentration of the liquid is maintained within a reasonable range.

[0082] In the embodiment of the present invention, the controller controls the operating frequency of the first circulation pump 3 so that the second temperature difference is within the range of the second target temperature difference, thereby ensuring that the concentration of the liquid is maintained within a reasonable range, which is beneficial to further improve the reliability of the energy tower heat pump system.

[0083] like Figure 1 As shown, in an optional embodiment, the energy tower heat pump system also includes a concentrating device, which includes a liquid storage tank 14 and an ice chamber 16. The liquid storage tank 14 is connected to the ice chamber 16. The liquid storage tank 14 is used to store fluid, and the ice chamber 16 is used to concentrate the liquid.

[0084] Specifically, a cryogenic fluid is stored in the liquid storage tank 14, and the cryogenic fluid enters the freezing chamber 16 through the second valve 15. The cryogenic fluid and liquid are mixed in the freezing chamber 16. After the cryogenic fluid cools and freezes the liquid, the ice slurry is discharged from the bottom of the freezing chamber 16, and the concentrated liquid returns to the bottom of the spray tower 1.

[0085] A third valve 17 is provided between one end of the freezing chamber 16 and the first circulation pump 3, and a fourth valve 18 is provided between the other end of the freezing chamber 16 and the spray tower 1. When the liquid in the spray tower 1 deviates from the preset concentration due to dilution, the third valve 17 is opened, the first valve 20 is closed, and the diluted liquid enters the freezing chamber 16 for freeze concentration. After the freeze concentration is completed, the fourth valve 18 is opened, and the concentrated liquid enters the spray tower 1 to complete the adjustment of the liquid concentration.

[0086] In the embodiment of the present invention, the concentrating device is used to cope with the situation where the liquid is diluted due to abnormal operating conditions of the equipment, and the diluted liquid is concentrated by a cryogenic fluid to ensure that the liquid concentration is maintained within a reasonable range.

[0087] like Figure 1 As shown, in an optional embodiment, the energy tower heat pump system further includes a fifth temperature sensor 19, and the fifth temperature sensor 19 is used to detect the temperature in the ice chamber 16;

[0088] The controller controls the flow rate of the fluid according to the comparison result between the temperature in the freezing chamber 16 and the target temperature.

[0089] Specifically, the fifth temperature sensor 19 is disposed at the freezing chamber 16 , and is used to detect the temperature of the ice slurry solution after the liquid in the freezing chamber 16 is mixed with the cryogenic fluid. The fifth temperature sensor 19 is in communication connection with the controller.

[0090] The detected ice slurry solution temperature is lower than the target temperature, indicating that the flow rate of the cryogenic fluid needs to be reduced, and the opening of the second valve 15 is reduced at this time; the detected ice slurry solution temperature is higher than the target temperature, indicating that the flow rate of the cryogenic fluid needs to be increased at this time to enhance the degree of freezing and concentration of the liquid by the cryogenic fluid, and the opening of the second valve 15 is increased at this time to allow more cryogenic fluid to enter the freezing chamber 16.

[0091] like Figure 1 As shown, in an optional embodiment, the energy tower heat pump system further includes a density sensor 12, which is disposed at the bottom of the spray tower 1 and is used to detect the density of the liquid;

[0092] The controller controls the start or stop of the concentrating device according to the comparison result between the density of the liquid and the target density.

[0093] Specifically, the density sensor 12 is used to detect the density of the liquid in the spray tower 1, and the density sensor 12 is communicatively connected with the controller.

[0094] If the density of the liquid detected by the density sensor 12 is lower than the target density, the third valve 17 is opened to start the concentration function of the concentration device until the concentration of the liquid reaches the target density, and the third valve 17 is closed to stop the freeze concentration.

[0095] If the density of the liquid detected by the density sensor 12 is higher than the target density, the fifth valve 21 is opened to add water to the spray tower 1 until the density of the liquid reaches the target density, and the fifth valve 21 is closed to ensure that the concentration of the liquid is within a reasonable range through the density correction mechanism.

[0096] In an embodiment of the present invention, the density sensor 12 detects the density of the liquid, and the controller controls the start or shut down of the concentration device and the start or shut down of the fifth valve 21 according to the comparison result between the density of the liquid and the target density, thereby ensuring that the concentration of the liquid is maintained within a reasonable range and improving the reliability of the energy tower heat pump system.

[0097] like Figure 1 As shown, in an optional embodiment, the energy tower heat pump system also includes a third heat exchanger 26 and a second circulation pump 25.

[0098] One end of the second circulation pump 25 is connected to the second heat exchanger 24 , and the other end of the second circulation pump 25 is connected to the third heat exchanger 26 .

[0099] The following explanation is given by taking heating application as an example. The third heat exchanger 26 is a radiator. After the gaseous refrigerant condenses and releases heat in the second heat exchanger 24, the low-temperature water in the second circulation pump 25 absorbs the latent heat of condensation in the second heat exchanger 24 and transfers the heat to the user through the third heat exchanger 26.

[0100] Furthermore, the heating system also includes a second fan 22, which is arranged opposite to the heat exchange surface of the second heat exchanger 24. The second fan 22 blows low-temperature wind of the ambient air to the heat exchange surface of the second heat exchanger 24. The low-temperature wind exchanges heat with the second heat exchanger 24, and the low-temperature wind absorbs latent heat of condensation and blows the heat to the surrounding environment to achieve the purpose of heating.

[0101] In an optional embodiment, the compressor 6 is a centrifugal compressor or a screw compressor.

[0102] When a centrifugal compressor is used, the adjustment range is 40 to 100%, and when a screw compressor is used, the adjustment range is 10 to 100%.

[0103] The following takes a 1MW heating project for a building in a certain area as an example to explain the application of the energy tower heat pump system.

[0104] A certain area is located in the northern temperate monsoon region and has a temperate monsoon climate. Due to the direct regulation of the marine environment, the urban area is affected by the southeast monsoon, ocean currents and water masses on the ocean surface, so it also has significant marine climate characteristics. The air is humid, the rainfall is abundant, the temperature is moderate, and the four seasons are distinct. According to the meteorological data of more than 100 years since 1898, the annual average temperature in the urban area is 12.7℃, the extreme high temperature is 38.9℃ (July 15, 2002), and the extreme low temperature is -16.9℃ (January 10, 1931). The annual average precipitation is 662.1 mm, and the rainfall in spring, summer, autumn and winter accounts for 17%, 57%, 21% and 5% of the annual precipitation respectively. The annual average relative humidity is 73%, the highest in July is 89%; the lowest in December is 68%.

[0105] In view of the typical climate characteristics of the above-mentioned region, in this embodiment, in order to meet the winter heating demand, the ambient air temperature is designed according to the worst temperature condition of -16.9°C. The relative humidity in a certain region in winter is relatively low, and is designed according to the annual average relative humidity of 73%.

[0106] According to the corresponding relationship between the first target temperature difference and the ambient temperature and ambient relative humidity listed in Table 1, it can be known that under the conditions of an ambient temperature of -16.9°C and an ambient relative humidity of 73%, the first target temperature difference is 4°C.

[0107] The liquid in the spray tower 1 uses a solution with a freezing point temperature above -25°C, and preferably a high-concentration ion solution, such as lithium bromide, lithium chloride, sodium nitrate, ammonium nitrate, potassium carbonate, potassium formate, ammonium formate, methyl acetate, methyl acetate, ammonium acetate, potassium chloride, ammonium formate, calcium chloride and other ion solutions. The temperature of the liquid in the spray tower 1 is preferably -22 to -23°C.

[0108] The spray component 4 adopts an extra-large diameter to prevent clogging, and uses an axial flow solid cone nozzle, the nozzle angle is 120 degrees, and the nozzle pressure is 0.5-1.5 bar.

[0109] The flow rate of the first circulation pump 3 is preferably 400 to 600 m 3 / h, the head is preferably 10-15m; the flow rate of the first fan 2 is preferably 500000-700000m 3 / h, and the pressure rise is preferably 100-150Pa.

[0110] The flow rate of the second circulation pump 25 is 200-250m 3 / h, the head is 15~30m.

[0111] The first heat exchanger 5 is a shell and tube heat exchanger, preferably a double-pass or four-pass heat exchanger, with a heat exchange tube diameter preferably between 20 and 32 mm and a heat exchange area preferably between 120 and 150 m 2 between.

[0112] The tube side of the first heat exchanger 5 is filled with a refrigerant, the refrigerant is R22, R22 belongs to hydrochlorofluorocarbons, and the evaporation temperature of the refrigerant is about -25 to -26°C.

[0113] The second heat exchanger 24 is a plate type or a shell and tube type heat exchanger.

[0114] Compressor 6 is a single screw compressor, wherein the suction temperature is -25 to -26°C, the exhaust temperature is 49 to 51°C, the variable frequency motor power is 350kW, and the adjustment range is 10 to 100%.

[0115] The temperature of the liquid is about -22 to -23°C, the inlet air temperature is about -16.9°C, the outlet air temperature is about -21°C, and the temperature difference between the liquid and the air is controlled at 2 to 5°C.

[0116] The measuring ranges of the first temperature sensor 7, the second temperature sensor 9, the third temperature sensor 11, the fourth temperature sensor 13 and the fifth temperature sensor 19 are all -50 to 100°C, the measuring ranges of the first humidity sensor 8 and the second humidity sensor 10 are all 0 to 100% RH, the measuring range of the density sensor 12 is 0.5 to 2.5 g / cc, and the input and output signals of the sensors are 4 to 20 mA.

[0117] The first circulation pump 3 drives the liquid to move from top to bottom in the spray tower 1, and the first fan 2 drives the air to move from bottom to top in the spray tower 1. The liquid and the air undergo sufficient heat exchange, and the liquid falls onto the surface of the first heat exchanger 5 during the downward movement. The liquid forms a uniform film outside the horizontal tube of the first heat exchanger 5, and the heat absorbed by the liquid is transferred to the refrigerant in the first heat exchanger 5.

[0118] The liquid refrigerant in the first heat exchanger 5 absorbs heat and evaporates to become a gaseous refrigerant. The gaseous refrigerant enters the second heat exchanger 24 through the single-screw compressor 6. The gaseous refrigerant condenses and releases heat in the second heat exchanger 24 to become a liquid refrigerant. The liquid refrigerant flows back to the first heat exchanger 5 through the sixth valve 23.

[0119] The second circulation pump 25 delivers low-temperature water to the second heat exchanger 24 . After the low-temperature water absorbs the latent heat of condensation, it transfers the heat to the user through the third heat exchanger 26 .

[0120] The second fan 22 blows ambient air to the heat exchange surface of the second heat exchanger 24. The low-temperature wind blowing toward the heat absorbs the latent heat of condensation and is then blown into the surrounding environment to achieve the purpose of heating.

[0121] The controller controls the operating frequency of the first fan 2 according to the comparison result between the first temperature difference and the first target temperature difference, and controls the operating frequency of the first circulation pump 3 according to the comparison result between the second temperature difference and the second target temperature difference, to ensure that the concentration of the liquid is within a reasonable range. The specific control method is the same as above and will not be repeated here.

[0122] The liquid storage tank 14 stores cryogenic fluid. The type of cryogenic fluid is not limited. It is preferably a fluid that does not pollute the environment. It can be liquid oxygen, liquid air, etc. The temperature of liquid oxygen and liquid air is generally around -200°C. The cryogenic fluid enters the freezing chamber 16 and mixes with the diluted liquid, so that it is cooled to the freezing point and freezes, thereby achieving the purpose of concentrating the liquid.

[0123] A filter screen is arranged in the ice-making chamber 16 , and the filter accuracy is 10-30 meshes. The filter screen intercepts ice crystals in the ice slurry solution and allows the concentrated liquid to pass freely, and the concentrated liquid enters the bottom of the spray tower 1 .

[0124] When the concentration of the liquid in the spray tower 1 deviates from the preset concentration due to dilution, the third valve 17 is opened, and the diluted liquid enters the freezing chamber 16. The low-temperature fluid stored in the liquid storage tank 14 enters the freezing chamber 16 through the second valve 15. After the diluted liquid is mixed with the low-temperature fluid and cooled to freeze, the ice slurry is discharged from the bottom of the freezing chamber 16, and the concentrated liquid returns to the bottom of the spray tower 1 through the fourth valve 18, thereby completing the adjustment of the liquid concentration.

[0125] The controller controls the flow rate of the cryogenic fluid according to the comparison result between the temperature in the freezing chamber 16 and the target temperature, and controls the start or stop of the concentration device according to the comparison result between the density of the liquid and the target density. The specific control method is the same as above and will not be repeated here.

[0126] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An energy tower heat pump system, characterized in that: include: A spray tower, a liquid pipeline, a first heat exchanger, a second heat exchanger, a first fan, a first temperature sensor, a second temperature sensor and a controller; The first heat exchanger is disposed in the spray tower, the first heat exchanger and the second heat exchanger form a refrigerant circuit, and the liquid pipeline can transport the liquid at the bottom of the spray tower to the top of the spray tower so that the liquid contacts the first heat exchanger; An air inlet is provided at the bottom of the spray tower, and an air outlet is provided at the top of the spray tower. The first temperature sensor is provided at the air inlet and is used to detect the air inlet temperature of the air inlet. The first fan and the second temperature sensor are both provided at the air outlet, and the second temperature sensor is used to detect the air outlet temperature of the air outlet. The controller determines a first temperature difference between the inlet air temperature and the outlet air temperature according to the inlet air temperature and the outlet air temperature, and controls the operating frequency of the first fan according to a comparison result between the first temperature difference and a first target temperature difference; The energy tower heat pump system further includes a humidity sensor, which is disposed at the air inlet and is used to detect the air humidity at the air inlet; the controller determines the first target temperature difference according to the air humidity; The liquid pipeline includes a first circulation pump and a spray assembly; the spray assembly is arranged between the first heat exchanger and the first fan, one end of the first circulation pump is connected to the bottom of the spray tower, and the other end of the first circulation pump is connected to the spray assembly.

2. The energy tower heat pump system according to claim 1, characterized in that: The first target temperature difference is 2-5°C.

3. The energy tower heat pump system according to claim 1, characterized in that: The energy tower heat pump system also includes a third temperature sensor and a fourth temperature sensor; The third temperature sensor is disposed at the bottom of the spray tower to detect the temperature of the liquid, and the fourth temperature sensor is disposed at the first heat exchanger to detect the evaporation temperature of the refrigerant; The controller determines a second temperature difference between the temperature of the liquid and the evaporation temperature of the refrigerant according to the temperature of the liquid and the evaporation temperature of the refrigerant, and controls the operation frequency of the first circulation pump according to a comparison result between the second temperature difference and a second target temperature difference.

4. The energy tower heat pump system according to claim 3, characterized in that: The second target temperature difference is 3-5°C.

5. The energy tower heat pump system according to claim 1, characterized in that: The energy tower heat pump system also includes a concentrating device, which includes a liquid storage tank and an ice chamber. The liquid storage tank is connected to the ice chamber. The liquid storage tank is used to store fluid, and the ice chamber is used to concentrate the liquid.

6. The energy tower heat pump system according to claim 5, characterized in that: The energy tower heat pump system further includes a fifth temperature sensor, the fifth temperature sensor being used to detect the temperature in the freezing chamber; The controller controls the flow rate of the fluid according to a comparison result between the temperature in the freezing chamber and a target temperature.

7. The energy tower heat pump system according to claim 5, characterized in that: The energy tower heat pump system further comprises a density sensor, which is disposed at the bottom of the spray tower and is used to detect the density of the liquid; The controller controls activation or deactivation of the concentrating device according to a comparison result between the density of the liquid and a target density.

8. The energy tower heat pump system according to claim 1, characterized in that: The energy tower heat pump system also includes a third heat exchanger and a second circulation pump; One end of the second circulation pump is connected to the second heat exchanger, and the other end of the second circulation pump is connected to the third heat exchanger.

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