CN112944739B

CN112944739B - Dual cycle refrigeration system using dew point temperature cooling and control method thereof

Info

Publication number: CN112944739B
Application number: CN202110406787.1A
Authority: CN
Inventors: 谢文科; 吕东建; 廖宜利; 陈启凡; 李琪铎
Original assignee: Guangdong Haiwu Technology Co Ltd
Current assignee: Guangdong Haiwu Technology Co Ltd
Priority date: 2021-04-15
Filing date: 2021-04-15
Publication date: 2023-05-16
Anticipated expiration: 2041-04-15
Also published as: CN112944739A

Abstract

The invention discloses a double-circulation refrigerating system cooled by dew point temperature and a control method thereof, wherein the double-circulation refrigerating system cooled by dew point temperature specifically comprises a condenser, a first evaporator and a second evaporator; a water-cooling condensing pipe, an air-cooling condensing pipe and a surface cooler are arranged in the condenser; an airflow channel is formed between the air inlet and the air outlet of the condenser, and the surface cooler and the air-cooled condenser tube are sequentially arranged in the airflow channel; the outdoor air firstly exchanges heat with the surface air cooler after entering the condenser, the temperature is reduced, the heat exchange efficiency is higher when the outdoor air exchanges heat with the air-cooled condensing tube, meanwhile, the water-cooled condensing tube is used for independently cooling a loop with a pump body unit, the air-cooled condensing tube is used for independently cooling the loop with the compressor, namely, two kinds of circulation cannot interfere with each other, the condition that the air suction of the compressor brings liquid when the two kinds of circulation are switched is avoided, the compressor is prevented from being damaged, and meanwhile, the stability and the heat exchange efficiency of a double-circulation refrigerating system cooled by dew point temperature are improved.

Description

Dual cycle refrigeration system using dew point temperature cooling and control method thereof

Technical Field

The invention relates to the field of refrigeration equipment, in particular to a double-circulation refrigeration system cooled by dew point temperature and a control method thereof.

Background

At present, with the popularization of the concept of energy conservation and environmental protection, a refrigeration device with energy conservation or low power consumption is sought after. Among them, the compressor in the refrigeration apparatus is the highest power consumption component, and other components are beginning to be considered to replace the compressor.

The refrigeration equipment in the prior art mainly reduces the use of a compressor through two modes of switching, wherein the first mode is that when the outdoor environment temperature is lower, the refrigerant subjected to heat exchange through the evaporator is directly conveyed to the air-cooled condenser to exchange heat with an outdoor cold source, the cooled refrigerant returns to the evaporator through a fluorine pump, and the second mode is that when the outdoor environment temperature is higher, the refrigerant subjected to heat exchange through the evaporator is conveyed to the condenser through the compressor, and the refrigerant is cooled through the condenser and flows to the evaporator to complete heat exchange.

However, when the mode is frequently switched, the condition that liquid is mixed with gas is easy to occur when the compressor sucks the gaseous refrigerant, so that the compressor is easy to damage, the stability of the refrigerating device is reduced, and if the independent loop is only additionally arranged for the compressor or the fluorine pump, the refrigerating device is oversized, so that the refrigerating efficiency is influenced, therefore, the refrigerating device with high refrigerating efficiency and difficult damage of the compressor when the mode is frequently switched is necessary to be developed.

Disclosure of Invention

The invention aims to provide a double-circulation refrigerating system cooled by dew point temperature and a control method thereof, which are used for solving the problems that the existing refrigerating device cannot ensure that a compressor is not easy to damage and the refrigerating efficiency is high.

To achieve the purpose, the invention adopts the following technical scheme:

a dual cycle refrigeration system utilizing dew point temperature cooling includes a condenser, a first evaporator and a second evaporator;

a water-cooling condensing pipe, an air-cooling condensing pipe and a surface cooler are arranged in the condenser; the surface cooler and the air-cooled condenser tube are sequentially arranged in the airflow channel;

the air-cooled condensing pipe comprises an air-cooled condensing inlet and an air-cooled condensing outlet; the water-cooling condensing pipe comprises a water-cooling condensing inlet and a water-cooling condensing outlet;

the first evaporation outlet of the first evaporator is communicated with the water-cooling condensation inlet, the second evaporation outlet of the second evaporator is communicated with the air-cooling condensation inlet, the second evaporator is communicated with a compressor, and the compressor is communicated between the second evaporation outlet and the air-cooling condensation inlet;

the air cooling condensation outlet is communicated with a second evaporation inlet of the second evaporator, the water cooling condensation outlet is communicated with a first evaporation inlet of the first evaporator, the first evaporator is communicated with a pump body unit, and the pump body unit is communicated between the water cooling condensation outlet and the first evaporation inlet.

Optionally, a first branch is communicated between the first evaporation outlet and the second evaporation outlet, and a first electromagnetic valve is arranged in the first branch;

a second branch is communicated between the first evaporation outlet and the compression outlet of the compressor, and a second electromagnetic valve is arranged in the second branch.

Optionally, a third branch is communicated between the air cooling condensation outlet and the water cooling condensation inlet, and a third electromagnetic valve is arranged in the third branch;

and a fourth electromagnetic valve is arranged in a loop between the air-cooled condensing outlet and the second evaporation inlet.

Optionally, the system further comprises an ambient temperature sensor, an indoor temperature sensor and an ambient humidity sensor; a fifth branch is arranged between the first evaporation inlet and the second evaporation inlet, and a fifth electromagnetic valve is arranged in the fifth branch;

a first one-way valve is arranged in a loop between the outlet of the compressor and the second branch and is used for preventing the refrigerant from flowing back to the compressor; the loop between the first branch and the second branch is provided with a second one-way valve, and the second one-way valve is used for preventing the refrigerant from flowing back to the first branch.

Optionally, the outdoor dry bulb temperature sensor is further included, and a sixth electromagnetic valve is arranged in a loop between the second branch and the third branch.

Optionally, one end of the surface cooler is communicated with a water-cooling condenser for cooling the water-cooling condenser pipe, and the other end of the surface cooler is communicated with a spraying device;

the bottom of the spraying device is provided with a cooling water tray which is used for recycling cooling water flowing down from the spraying device; the cooling water tray is communicated with a water pump, and the water pump is communicated with the water-cooling condenser and used for leading the cooling water pump to the water-cooling condenser.

A control method of a dual cycle refrigeration system using dew point temperature cooling, applied to the dual cycle refrigeration system using dew point temperature cooling as described above, the control method comprising:

acquiring an outdoor temperature value;

judging whether the outdoor temperature value is lower than a preset first temperature threshold value or not;

if not, starting the compressor;

if yes, the compressor is shut down and the pump body unit is started.

pre-establishing a dew point relation formula for obtaining outdoor dew point temperature according to a temperature value and a humidity value;

acquiring an outdoor temperature value, an indoor temperature value and an outdoor humidity value;

obtaining an outdoor dew point temperature value according to the outdoor temperature value, the outdoor humidity value and the dew point relation;

judging whether the sum of the outdoor dew point temperature value and a preset temperature difference value is smaller than the indoor temperature value or not;

if yes, the first electromagnetic valve is controlled to be closed, the second electromagnetic valve is controlled to be closed, the third electromagnetic valve is controlled to be closed, the fourth electromagnetic valve is controlled to be opened, and the fifth electromagnetic valve is controlled to be closed;

if not, the first electromagnetic valve is controlled to be opened, the second electromagnetic valve is controlled to be opened, the third electromagnetic valve is controlled to be opened, the fourth electromagnetic valve is controlled to be closed, and the fifth electromagnetic valve is controlled to be opened.

Optionally, the steps are as follows: if yes, control the first solenoid valve to close, control the second solenoid valve to close, control the third solenoid valve to close, control the fourth solenoid valve to open, after controlling the fifth solenoid valve to close, still include:

judging whether the outdoor dew point temperature value is smaller than a preset second temperature threshold value or not;

if yes, the first electromagnetic valve is controlled to be closed, the second electromagnetic valve is controlled to be closed, the third electromagnetic valve is controlled to be opened, the fourth electromagnetic valve is controlled to be closed, and the fifth electromagnetic valve is controlled to be opened;

if not, the first electromagnetic valve is controlled to be closed, the second electromagnetic valve is controlled to be closed, the third electromagnetic valve is controlled to be closed, the fourth electromagnetic valve is controlled to be opened, and the fifth electromagnetic valve is controlled to be closed.

acquiring an outdoor dry bulb temperature value;

judging whether the outdoor dry bulb temperature value is smaller than a preset third temperature threshold value or not;

if yes, the first electromagnetic valve is controlled to be closed, the second electromagnetic valve is controlled to be opened, the third electromagnetic valve is controlled to be opened, the fourth electromagnetic valve is controlled to be closed, the fifth electromagnetic valve is controlled to be opened, and the sixth electromagnetic valve is controlled to be closed;

if not, the first electromagnetic valve is controlled to be opened, the second electromagnetic valve is controlled to be opened, the third electromagnetic valve is controlled to be opened, the fourth electromagnetic valve is controlled to be closed, the fifth electromagnetic valve is controlled to be opened, and the sixth electromagnetic valve is controlled to be closed.

Compared with the prior art, the invention has the following beneficial effects:

according to the double-circulation refrigerating system cooled by the dew point temperature and the control method thereof, the water-cooling condensing pipe and the air-cooling condensing pipe are integrated in the condenser, wherein outdoor air exchanges heat with the surface cooler firstly after entering the condenser, the temperature is reduced to be near the dew point temperature, the outdoor environment temperature of the starting operation of pump body units such as a fluorine pump is improved (the starting of the existing pump body units needs to be lower than the actual outdoor temperature to the indoor temperature, and the temperature difference between the indoor temperature and the outdoor temperature reaches a certain difference value, the operation time of the pump body units is prolonged, the energy-saving effect is improved, the heat exchange efficiency is higher when the outdoor air exchanges heat with the air-cooling condensing pipe, meanwhile, the water-cooling condensing pipe independently cools a loop with the pump body units, the air-cooling condensing pipe independently cools a loop with the compressor, namely, the two loops cannot interfere with each other, the condition that the compressor is sucked in when the two loops are switched is avoided, the damage of the compressor is avoided, and the stability and the heat exchange efficiency of the double-circulation refrigerating system cooled by the dew point temperature are improved.

Drawings

In order to more clearly illustrate the embodiments of the invention or the technical solutions of the prior art, the drawings which are used in the description of the embodiments or the prior art will be briefly described, it being obvious that the drawings in the description below are only some embodiments of the invention, and that other drawings can be obtained from these drawings without inventive faculty for a person skilled in the art.

The structures, proportions, sizes, etc. shown in the drawings are shown only in connection with the present disclosure, and are not intended to limit the scope of the invention, since any modification, variation in proportions, or adjustment of the size, etc. of the structures, proportions, etc. should be considered as falling within the spirit and scope of the invention, without affecting the effect or achievement of the objective.

FIG. 1 is a schematic diagram of a circuit structure of a dual-cycle refrigeration system using dew point cooling according to an embodiment of the present invention;

fig. 2 is a schematic diagram of a pipeline structure of a dual-cycle refrigeration system cooled by dew point temperature according to a second embodiment of the present invention;

fig. 3 is a schematic diagram of a pipeline structure of a dual-cycle refrigeration system cooled by dew point temperature according to a third embodiment of the present invention;

FIG. 4 is a schematic view of a condenser according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of heat exchange of a condenser according to an embodiment of the present invention;

FIG. 6 is a first flow chart of a control method according to a fourth embodiment of the present invention;

FIG. 7 is a second flow chart of a control method according to a fifth embodiment of the present invention;

fig. 8 is a schematic diagram of a first sub-flow of a control method according to a fifth embodiment of the present invention;

fig. 9 is a schematic diagram of a second sub-flow of the control method according to the fifth embodiment of the present invention;

fig. 10 is a third flow chart of a control method according to a fifth embodiment of the present invention.

Illustration of: 1. a condenser; 11. an air-cooled condensing inlet; 12. an air-cooled condensing outlet; 13. a water-cooling condensing inlet; 14. a water-cooling condensation outlet;

21. a first evaporator; 211. a first evaporation inlet; 212. a first evaporation outlet; 22. a second evaporator; 221. a second evaporation inlet; 222. a second evaporation outlet;

3. a compressor; 4. a pump body unit;

51. a first electromagnetic valve; 52. a second electromagnetic valve; 53. a third electromagnetic valve; 54. a fourth electromagnetic valve; 55. a fifth electromagnetic valve; 56. a sixth electromagnetic valve;

61. a first branch; 62. a second branch; 63. a third branch; 65. a fifth branch;

71. a first one-way valve; 72. a second one-way valve;

81. a blower; 82. an air-cooled condenser tube; 83. a spraying device; 84. a surface cooler; 85. a cooling water tray; 86. a water pump; 87. a water-cooled condenser; 88. a water-cooled condenser tube; 89. a water supplementing valve; 91. an ambient temperature sensor; 92. a liquid storage device; 93. a first throttle valve; 94. and a second throttle valve.

Detailed Description

In order to make the objects, features and advantages of the present invention more comprehensible, the technical solutions in the embodiments of the present invention are described in detail below with reference to the accompanying drawings, and it is apparent that the embodiments described below are only some embodiments of the present invention, but not all embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In the description of the present invention, it should be understood that the directions or positional relationships indicated by the terms "upper", "lower", "top", "bottom", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention. It is noted that when one component is referred to as being "connected" to another component, it can be directly connected to the other component or intervening components may also be present.

The technical scheme of the invention is further described below by the specific embodiments with reference to the accompanying drawings.

Referring to fig. 1 to 10, fig. 1 is a schematic diagram of a pipeline structure of a dual-cycle refrigeration system using dew point cooling according to a first embodiment of the present invention, fig. 2 is a schematic diagram of a pipeline structure of a dual-cycle refrigeration system using dew point cooling according to a second embodiment of the present invention, fig. 3 is a schematic diagram of a pipeline structure of a dual-cycle refrigeration system using dew point cooling according to a third embodiment of the present invention, fig. 4 is a schematic diagram of a condenser according to a first embodiment of the present invention, fig. 5 is a schematic diagram of a heat exchange of the condenser according to a second embodiment of the present invention, fig. 6 is a schematic diagram of a first flow of a control method according to a fourth embodiment of the present invention, fig. 7 is a schematic diagram of a second flow of a control method according to a fifth embodiment of the present invention, fig. 8 is a first sub-flow of a control method according to a fifth embodiment of the present invention, fig. 9 is a second sub-flow of a control method according to a fifth embodiment of the present invention, and fig. 10 is a third flow of a control method according to the fifth embodiment of the present invention.

Example 1

The dual-cycle refrigerating system utilizing dew point temperature cooling is mainly applied to a scene of heat dissipation of a machine room, and through improvement of a condenser and a pipeline, the problem of liquid carrying during air suction of a compressor is avoided, and meanwhile heat exchange efficiency is improved.

As shown in fig. 1, the dual cycle refrigeration system provided by the embodiment of the present invention may include an indoor unit and an outdoor unit, specifically, the outdoor unit includes a condenser 1, and the indoor unit includes a first evaporator 21 and a second evaporator 22. It is to be understood that the dual cycle refrigeration system may also include an integrated unit including the condenser 1, the first evaporator 21 and the second evaporator 22.

A water-cooling condensing pipe 88, an air-cooling condensing pipe 82 and a surface cooler 84 are arranged in the condenser 1; the condenser 1 is provided with an air inlet and an air outlet, an air flow channel is formed between the air inlet and the air outlet, and a surface cooler 84 and an air-cooled condenser tube 82 are sequentially arranged in the air flow channel.

The air-cooled condensing duct 82 includes an air-cooled condensing inlet 11 and an air-cooled condensing outlet 12; the water-cooled condensing duct 88 includes a water-cooled condensing inlet 13 and a water-cooled condensing outlet 14.

The first evaporation outlet 212 of the first evaporator 21 is communicated with the water-cooling condensation inlet 13, the second evaporation outlet 222 of the second evaporator 22 is communicated with the air-cooling condensation inlet 11, the second evaporator 22 is communicated with the compressor 3, and the compressor 3 is communicated between the second evaporation outlet 222 and the air-cooling condensation inlet 11.

The air-cooled condensing outlet 12 is communicated with a second evaporation inlet 221 of the second evaporator 22, the water-cooled condensing outlet 14 is communicated with a first evaporation inlet 211 of the first evaporator 21, the first evaporator 21 is communicated with a pump body unit 4, and the pump body unit 4 is communicated between the water-cooled condensing outlet 14 and the first evaporation inlet 211. The pump body unit 4 may be a refrigerant pump.

Specifically, by integrating the water-cooled condenser tube 88 and the air-cooled condenser tube 82 in the condenser 1, wherein the outdoor air exchanges heat with the surface cooler 84 after entering the condenser 1, the temperature is reduced to be near the dew point temperature, the outdoor environment temperature of the pump body unit 4 such as the fluorine pump for starting operation (the starting of the existing pump body unit needs the actual outdoor temperature to be lower than the indoor temperature, and the indoor and outdoor temperature difference reaches a certain difference value) is improved, the operation time of the pump body unit 4 is prolonged, the energy-saving effect is improved, the heat exchange efficiency when the outdoor air exchanges heat with the air-cooled condenser tube is higher, the heat exchange efficiency when the outdoor air exchanges heat with the air-cooled condenser tube 82 is higher, meanwhile, the water-cooled condenser tube 88 independently cools the loop with the pump body unit 4, the air-cooled condenser tube 82 independently cools the loop with the compressor 3, namely, the two loops do not interfere with each other, the condition that the compressor 3 is sucked in the liquid is avoided when the two loops are switched, the damage of the compressor 3 is avoided, and the stability and the heat exchange efficiency of the dual-cycle refrigerating system cooled by the dew point temperature is improved.

For example, there is a case that when the outdoor environment temperature is 40 ℃, the dew point temperature may be 20 ℃, and the starting condition of the pump body unit 4 such as the fluorine pump is related to the air inlet temperature of the air-cooled condenser tube 82, which is equivalent to that even if the outdoor temperature is 40 ℃, the dual-cycle refrigeration system cooled by the dew point temperature can still start the pump body unit 4 to achieve the purpose of energy saving, and the existing dual-cycle system of the fluorine pump can only start when the outdoor temperature is lower than 10 ℃ or the indoor and outdoor temperature difference reaches a certain difference value (the nature of energy saving of the fluorine pump is realized by the physical state change of the indoor and outdoor temperature difference driving refrigerant, and the indoor temperature of a conventional machine room is generally required to be maintained at 25 ℃).

Therefore, as the air temperature exchanging heat with the air-cooled condenser tube 82 can approach the dew point temperature, the outdoor environment temperature of the dual-cycle refrigerating system cooled by the dew point temperature entering the fluorine pump mode is improved, the operation time of the fluorine pump can be prolonged, and the operation time of the compressor 3 is shortened, so that the energy saving purpose of the system is realized, the energy efficiency is obviously improved, the pump body units 4 such as the fluorine pump are communicated with the water-cooled condenser tube 88, the water-cooled cooling efficiency is high, and the heat exchange efficiency of the unit can be enhanced to the greatest extent.

In an alternative embodiment, the water cooled condenser 87 may be in the form of a plate heat exchanger, a double pipe heat exchanger, a shell and tube heat exchanger, or the like.

Additionally, as shown in fig. 4 and 5, a water-cooling condenser 87 for cooling a water-cooling condenser pipe 88 is connected to one end of the surface cooler 84, and a shower 83 is connected to the other end of the surface cooler 84.

The bottom of the spraying device 83 is provided with a cooling water tray 85, and the cooling water tray 85 is used for recycling cooling water flowing down from the spraying device 83; the cooling water tray 85 is communicated with a water pump 86, and the water pump 86 is communicated with a water-cooled condenser 87 for pumping the cooling water to the water-cooled condenser 87. Wherein, condenser 1 is through integrating forced air cooling condenser pipe 82 and water-cooling condenser pipe 88 wherein, and single fan 81 just can promote the heat transfer to forced air cooling condenser pipe 82 and water-cooling condenser pipe 88, has the advantage that takes up an area of the space. Additionally, a filler is further disposed between the spraying device 83 and the cooling water tray 85, and the filler can be made of asbestos, wet film, polymer plastic, etc. for absorbing water, evaporating and cooling, and prolonging the contact time of the cooling liquid and air to make the air reach the dew point temperature. In one embodiment, the coolant line outlets of the water cooled condenser 87 are each connected to two spray devices 83 and are merged with the coolant in the flow path of the surface cooler 84 before spraying into the packing.

More specifically, the air-cooled condensing process is as follows: the initial temperature and humidity of the outdoor air are shown as state 1 in fig. 5, after the outdoor air is subjected to heat exchange by the surface cooler 84, the outdoor air is subjected to constant humidity cooling to be close to the temperature of the cooling liquid, namely, state 2 is reached, then the air is fully contacted with water in the filler below the spraying device 83, the constant enthalpy cooling is carried out, and the state 3 is reached, and finally, the temperature can be close to the dew point temperature of the air, and then the air is contacted with the air-cooled condensing pipe 82 for heat exchange.

The water-cooling condensation process is as follows: the state of water in the cooling water tray 85 is in the state A in fig. 5, the water passes through the water-cooled condenser 87 through the water pump 86 to complete the cooling of the water-cooled condenser tube 88, then is conveyed to the surface cooler 84, is indirectly heat-exchanged with outdoor air and then is heated to the state B, then is fully contacted with air again in the spraying device 83 through the spraying system at the top of the spraying device 83, absorbs heat due to the evaporation of water, is cooled to the state A, and then flows to the cooling water tray 85.

In summary, the dual-cycle refrigeration system using dew point temperature for cooling provided in this embodiment can avoid the problem of compressor suction liquid, fully utilize the outdoor cold source, and have advantages such as heat exchange efficiency is high, energy efficiency is high, stability is high.

Example two

As shown in fig. 2, the dual cycle refrigeration system using dew point temperature cooling according to the embodiment of the present invention includes an indoor unit including a condenser 1 and an outdoor unit including a first evaporator 21 and a second evaporator 22. The structure of the condenser 1 is the same as that of the first embodiment. Wherein, the first evaporation inlet 221 of the first evaporator 21 is communicated with a first throttle valve 93, and the second evaporation inlet 221 of the second evaporator 22 is communicated with a second throttle valve 94, so as to adjust the flow rate of the inlet of the evaporator.

A water-cooling condensing pipe 88, an air-cooling condensing pipe 82 and a surface cooler are arranged in the condenser 1; the condenser 1 is provided with an air inlet and an air outlet, an air flow channel is formed between the air inlet and the air outlet, and the surface cooler and the air-cooled condenser tube 82 are sequentially arranged in the air flow channel.

The air-cooled condensing outlet 12 is communicated with a second evaporation inlet 221 of the second evaporator 22, the water-cooled condensing outlet 14 is communicated with a first evaporation inlet 211 of the first evaporator 21, the first evaporator 21 is communicated with a pump body unit 4, and the pump body unit 4 is communicated between the water-cooled condensing outlet 14 and the first evaporation inlet 211.

Further, a first branch 61 is communicated between the first evaporation outlet 212 and the second evaporation outlet 222, and a first electromagnetic valve 51 is arranged in the first branch 61. The first solenoid valve 51 serves to prevent the compressor from sucking the liquid when both the compressor 3 and the pump body unit 4 are operated, and also serves to fully utilize the first evaporator 21 and the second evaporator 22 when the compressor 3 or the pump body unit 4 is operated alone.

Further, a second branch 62 is communicated between the first evaporation outlet 212 and the compression outlet of the compressor 3, and a second electromagnetic valve 52 is arranged in the second branch 62. The second electromagnetic valve 52 can switch between the water-present mode and the water-free mode of the dual-cycle refrigeration system according to whether water is present in the condenser 1, for example, when water is absent in the condenser 1 or the outdoor temperature is low enough to solidify into ice, the second electromagnetic valve 52 is closed to enable the dual-cycle refrigeration system to dissipate heat only through air cooling. It is to be added that the cooling water tray 85 is provided with a water supplementing port, the water supplementing port is communicated with a water supplementing valve 89, and when water is lacked, water can be supplemented to the condenser 1 from the outside by opening the water supplementing valve 89.

Further, a third branch 63 is communicated between the air-cooled condensing outlet 12 and the water-cooled condensing inlet 13, and a third electromagnetic valve 53 is arranged in the third branch 63.

The circuit between the air-cooled condensing outlet 12 and the second evaporation inlet 221 is provided with a fourth solenoid valve 54.

Further, the dual cycle refrigeration system cooled by dew point temperature further includes an ambient temperature sensor 91, an indoor temperature sensor, and an ambient humidity sensor; a fifth branch 65 is provided between the first evaporation inlet 211 and the second evaporation inlet 221, and a fifth solenoid valve 55 is provided in the fifth branch 65. The indoor temperature sensor can be arranged indoors or at the air inlet of the evaporator and used for detecting indoor temperature values.

The circuit between the compressor outlet and the second branch 62 is provided with a first non-return valve 71, the first non-return valve 71 being adapted to prevent refrigerant flowing back to the compressor 3; the circuit between the first branch 61 and the second branch 62 is provided with a second non-return valve 72, the second non-return valve 72 being adapted to preventing the refrigerant from flowing back to the first branch 61.

When the compressor 3 or the pump body unit 4 works independently through the arrangement of the third electromagnetic valve 53, the fourth electromagnetic valve 54 and the fifth electromagnetic valve 55, heat dissipation is carried out by utilizing the first evaporator 21 and the second evaporator 22, the increase of wind resistance caused by the fact that any evaporator does not participate in heat exchange is avoided, the heat exchange efficiency of the double-circulation refrigerating system is improved, a gas-liquid separator is not needed to be arranged for the compressor 3, and the cost is reduced.

On the basis of the above embodiment, the circuit between the second branch 62 and the third branch 63 is provided with the sixth solenoid valve 56.

In summary, the dual-cycle refrigeration system using dew point temperature for cooling provided in this embodiment can avoid the problem of compressor suction liquid, fully utilize outdoor cold source, and simultaneously have the capability of coping with various conditions, and have advantages of high heat exchange efficiency, high energy efficiency, high stability, low cost, etc.

Example III

As shown in fig. 6, the control method of the dual cycle refrigeration system using dew point cooling according to the present embodiment is applied to the dual cycle refrigeration system using dew point cooling according to the first to second embodiments, and includes:

s301, acquiring an outdoor temperature value;

s302, judging whether the outdoor temperature value is lower than a preset first temperature threshold value or not;

s303, if not, starting the compressor;

s304, if yes, the compressor is stopped and the pump body unit is started.

Example IV

As shown in fig. 7, the control method of the dual-cycle refrigeration system using dew point cooling according to the present embodiment is applied to the dual-cycle refrigeration system using dew point cooling as shown in fig. 2, and the control method includes:

s401, a dew point relation formula of outdoor dew point temperature is obtained according to a temperature value and a humidity value in advance. The dew point relation is shown in fig. 5, and the corresponding outdoor dew point temperature value can be obtained according to the temperature value and the humidity value.

S402, acquiring an outdoor temperature value, acquiring an indoor temperature value and acquiring an outdoor humidity value.

S403, obtaining an outdoor dew point temperature value according to the outdoor temperature value, the outdoor humidity value and the dew point relational expression.

S404, judging whether the sum of the outdoor dew point temperature value and the preset temperature difference value is smaller than the indoor temperature value.

And S405, if yes, controlling the first electromagnetic valve to be closed, controlling the second electromagnetic valve to be closed, controlling the third electromagnetic valve to be closed, controlling the fourth electromagnetic valve to be opened, and controlling the fifth electromagnetic valve to be closed.

And S406, if not, controlling the first electromagnetic valve to be opened, controlling the second electromagnetic valve to be opened, controlling the third electromagnetic valve to be opened, controlling the fourth electromagnetic valve to be closed, and controlling the fifth electromagnetic valve to be opened.

By way of example, the preset temperature difference is 5 °, and when the outdoor temperature value is lower than the indoor temperature value minus 5 °, there are two cycles of the dual cycle refrigeration system, specifically including a fluorine pump cycle and a compressor cycle; the fluorine pump circulation route is as follows: the liquid storage device 92, the pump body unit 4, the first throttle valve 93, the first evaporator 21, the second one-way valve 72, the water-cooled condenser tube 88 and the liquid storage device 92; the compressor cycle is as follows: compressor 3, first check valve 71, forced air cooling condenser 82, fourth solenoid valve 54, second choke 94, second evaporator 22, compressor 3. The circulation mode can fully utilize natural cold sources and can also utilize the compressor 3 to supplement cold, so that the double-circulation refrigerating system can achieve the refrigerating capacity required by customers on the premise of saving energy.

Further, as shown in fig. 8, step S405: if yes, control the first solenoid valve to close, control the second solenoid valve to close, control the third solenoid valve to close, control the fourth solenoid valve to open, after controlling the fifth solenoid valve to close, still include:

s4051, judging whether the outdoor dew point temperature value is smaller than a preset second temperature threshold value.

And S4052, if yes, controlling the first electromagnetic valve to be closed, controlling the second electromagnetic valve to be closed, controlling the third electromagnetic valve to be opened, controlling the fourth electromagnetic valve to be closed, and controlling the fifth electromagnetic valve to be opened.

And S4053, if not, controlling the first electromagnetic valve to be closed, controlling the second electromagnetic valve to be closed, controlling the third electromagnetic valve to be closed, controlling the fourth electromagnetic valve to be opened, and controlling the fifth electromagnetic valve to be closed.

By way of example, the second temperature threshold is set to 5 °, and when the outdoor dew point temperature value is below 5 °, there are two cycles of the dual cycle refrigeration system, including in particular a first fluorine pump cycle and a second fluorine pump cycle; the first fluorine pump circulation route is as follows: the liquid storage device 92, the pump body unit 4, the first throttle valve 93, the first evaporator 21, the second one-way valve 72, the water-cooled condenser tube 88 and the liquid storage device 92; the second fluorine pump circulation wheel system is as follows: the liquid storage device 92, the pump body unit 4, the fifth solenoid valve 55, the second throttle valve 94, the second evaporator 22, the compressor 3 (the compressor 3 is not turned on, and the refrigerant in a gaseous state may pass through the inside), the first check valve 71, the air-cooled condenser tube 82, the third solenoid valve 53, the water-cooled condenser tube 88, and the liquid storage device 92. Under the circulation mode, the double-circulation refrigerating system can fully utilize the two evaporators, so that the windage of the double-circulation refrigerating system is improved when one of the evaporators does not work, the overall efficiency of the double-circulation refrigerating system cooled by dew point temperature is reduced, and the efficient utilization of an outdoor cold source is realized.

It should be noted that, as shown in fig. 9, the dual-cycle refrigeration system further includes a water level sensor for detecting the water level of the cooling water tray 85; step S403: after obtaining the outdoor dew point temperature value according to the outdoor temperature value, the indoor temperature value and the dew point relation, the method further comprises the following steps:

s4031, acquiring a water level value;

s4032, judging whether the water level value is lower than a preset water level threshold value;

and S4033, if yes, controlling the first electromagnetic valve to be closed, controlling the second electromagnetic valve to be closed, controlling the third electromagnetic valve to be closed, controlling the fourth electromagnetic valve to be opened, and controlling the fifth electromagnetic valve to be closed.

S4034, if not, controlling the first electromagnetic valve to be opened, controlling the second electromagnetic valve to be opened, controlling the third electromagnetic valve to be opened, controlling the fourth electromagnetic valve to be closed, and controlling the fifth electromagnetic valve to be opened.

Illustratively, when water is absent from the cooling water pan 85, the dual cycle refrigeration system includes two cycles, specifically a compressor cycle; the first compressor cycle is: a compressor 3, a first check valve 71, an air-cooled condenser pipe 82, a fourth electromagnetic valve 54, a fifth electromagnetic valve 55, a first throttle valve 93, a first evaporator 21, and a compressor 3; the second compressor cycle is: compressor 3, first check valve 71, forced air cooling condenser 82, fourth solenoid valve 54, second choke 94, second evaporator 22, compressor 3.

Example five

As shown in fig. 10, the control method of the dual-cycle refrigeration system using dew point cooling according to the present embodiment is applied to the dual-cycle refrigeration system using dew point cooling shown in fig. 3, and the control method includes:

s501, acquiring an outdoor dry bulb temperature value.

S502, judging whether the outdoor dry bulb temperature value is smaller than a preset third temperature threshold value.

And S504, if yes, controlling the first electromagnetic valve to be closed, controlling the second electromagnetic valve to be opened, controlling the third electromagnetic valve to be opened, controlling the fourth electromagnetic valve to be closed, controlling the fifth electromagnetic valve to be opened, and controlling the sixth electromagnetic valve to be closed.

And S503, if not, controlling the first electromagnetic valve to be opened, controlling the second electromagnetic valve to be opened, controlling the third electromagnetic valve to be opened, controlling the fourth electromagnetic valve to be closed, controlling the fifth electromagnetic valve to be opened, and controlling the sixth electromagnetic valve to be closed.

By way of example, the third temperature threshold is set to 5 °, and when the outdoor dry bulb temperature value is less than 5 °, the water in the condenser 1 may be frozen, resulting in a dual cycle refrigeration system failure; therefore, the circulation mode can be performed in the case of water shortage; the device specifically comprises a first fluorine pump cycle and a second fluorine pump cycle; the first fluorine pump circulation route is as follows: the liquid storage device 92, the pump body unit 4, the first throttle valve 93, the first evaporator 21, the second one-way valve 72, the second electromagnetic valve 52, the air-cooled condenser tube 82, the third electromagnetic valve 53, the water-cooled condenser tube 88 (when the water cooling tray 85 lacks water or the water is frozen, the water-cooled condenser tube 88 in the water-cooled condenser does not exchange heat), the liquid storage device 92; the second fluorine pump circulation route is as follows: the liquid storage device 92, the pump body unit 4, the fifth electromagnetic valve 55, the second throttle valve 94, the second evaporator 22, the compressor 3 (not opened), the first check valve 71, the air-cooled condenser pipe 82, the third electromagnetic valve 53, the water-cooled condenser pipe 88 (when the water cooling tray 85 lacks water or the water is iced, the water-cooled condenser pipe 88 in the water-cooled condenser does not exchange heat), and the liquid storage device 92. The circulation mode can avoid the influence of freezing of cooling water on the double-circulation refrigerating system, and improves the stability of the double-circulation refrigerating system.

In summary, the control method of the dual-cycle refrigeration system using dew point temperature cooling provided by the embodiment can help the dual-cycle refrigeration system using dew point temperature cooling to cope with various situations, so that the dual-cycle refrigeration system using dew point temperature cooling has the characteristics of high heat exchange efficiency, high stability, energy conservation and environmental protection.

The above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A two-cycle refrigeration system cooled by dew point temperature, characterized by comprising a condenser (1), a first evaporator (21) and a second evaporator (22);

a water-cooling condensing pipe (88), an air-cooling condensing pipe (82) and a surface cooler (84) are arranged in the condenser (1); the condenser (1) is provided with an air inlet and an air outlet, an air flow channel is formed between the air inlet and the air outlet, and the surface cooler (84) and the air-cooled condensing tube (82) are sequentially arranged in the air flow channel;

the air-cooled condensing pipe (82) comprises an air-cooled condensing inlet (11) and an air-cooled condensing outlet (12); the water-cooling condensation pipe (88) comprises a water-cooling condensation inlet (13) and a water-cooling condensation outlet (14);

a first evaporation outlet (212) of the first evaporator (21) is communicated with the water-cooling condensation inlet (13), a second evaporation outlet (222) of the second evaporator (22) is communicated with the air-cooling condensation inlet (11), the second evaporator (22) is communicated with a compressor (3), and the compressor (3) is communicated between the second evaporation outlet (222) and the air-cooling condensation inlet (11);

the air-cooled condensing outlet (12) is communicated with a second evaporation inlet (221) of the second evaporator (22), the water-cooled condensing outlet (14) is communicated with a first evaporation inlet (211) of the first evaporator (21), the first evaporator (21) is communicated with a pump body unit (4), and the pump body unit (4) is communicated between the water-cooled condensing outlet (14) and the first evaporation inlet (211);

a third branch (63) is communicated between the air cooling condensation outlet (12) and the water cooling condensation inlet (13), and a third electromagnetic valve (53) is arranged in the third branch (63);

a fourth electromagnetic valve (54) is arranged in a loop between the air-cooled condensing outlet (12) and the second evaporation inlet (221).

2. The dual cycle refrigeration system cooled by dew point temperature according to claim 1, characterized in that a first branch (61) is communicated between the first evaporation outlet (212) and the second evaporation outlet (222), and a first solenoid valve (51) is arranged in the first branch (61);

a second branch (62) is communicated between the first evaporation outlet (212) and the compression outlet of the compressor (3), and a second electromagnetic valve (52) is arranged in the second branch (62).

3. The dual cycle refrigeration system cooled by dew point temperature according to claim 2, further comprising an ambient temperature sensor (91), an indoor temperature sensor, and an ambient humidity sensor; a fifth branch (65) is arranged between the first evaporation inlet (211) and the second evaporation inlet (221), and a fifth electromagnetic valve (55) is arranged in the fifth branch (65);

-the circuit between the compressor outlet and the second branch (62) is provided with a first non-return valve (71), the first non-return valve (71) being adapted to prevent refrigerant flowing back to the compressor (3); the circuit between the first branch (61) and the second branch (62) is provided with a second one-way valve (72), the second one-way valve (72) being used for preventing the refrigerant from flowing back to the first branch (61).

4. A dual cycle refrigeration system cooled by dew point temperature according to claim 3, further comprising an outdoor dry bulb temperature sensor, the circuit between the second branch (62) and the third branch (63) being provided with a sixth solenoid valve (56).

5. The double-circulation refrigerating system cooled by dew point temperature according to claim 1, wherein one end of the surface cooler (84) is communicated with a water-cooling condenser (87) for cooling the water-cooling condenser pipe (88), and the other end of the surface cooler (84) is communicated with a spraying device (83);

a cooling water tray (85) is arranged at the bottom of the spraying device (83), and the cooling water tray (85) is used for recycling cooling water flowing down from the spraying device (83); the cooling water tray (85) is communicated with a water pump (86), and the water pump (86) is communicated with the water-cooled condenser (87) and is used for pumping cooling water to the water-cooled condenser (87).

6. A control method of a two-cycle refrigeration system using dew point temperature cooling, applied to the two-cycle refrigeration system using dew point temperature cooling according to claim 1, comprising:

acquiring an outdoor temperature value;

if not, starting the compressor;

if yes, the compressor is shut down and the pump body unit is started.

7. A control method of a two-cycle refrigeration system using dew point temperature cooling, applied to the two-cycle refrigeration system using dew point temperature cooling according to claim 4, comprising:

8. The method for controlling a two-cycle refrigeration system cooled by dew point temperature according to claim 7, wherein said step of: if yes, control the first solenoid valve to close, control the second solenoid valve to close, control the third solenoid valve to close, control the fourth solenoid valve to open, after controlling the fifth solenoid valve to close, still include:

9. A control method of a two-cycle refrigeration system using dew point temperature cooling, applied to the two-cycle refrigeration system using dew point temperature cooling according to claim 4, comprising:

acquiring an outdoor dry bulb temperature value;