Fresh air conditioning unit for improving refrigeration efficiency by cooling fresh air through refrigeration return water

Abstract

The invention provides a fresh air conditioning unit which utilizes refrigeration return water to cool fresh air so as to improve refrigeration efficiency. The secondary mixing section is provided with an air pipe communicated with an air outlet of the exhaust unit, the air pipe is of a three-way structure, after air is exhausted from the exhaust unit, one end of the air pipe is communicated with the secondary mixing section, and the other end is communicated with the outside. The cooling pipeline in the surface cooling section is close to the first inlet end of the evaporator, and the cooling pipeline in the cooling section is close to the first outlet end of the evaporator. The cooling unit has the advantages that the temperature of fresh air newly flowing into the cooling unit is reduced through low-grade refrigeration return water, meanwhile, the temperature of chilled water return water is further increased, then the preliminarily cooled fresh air is mixed with primary return air, and then cold water flowing out of the evaporator is used for cooling. Fresh air is cooled through original chilled water return water, meanwhile, the chilled water return water temperature is increased, and under the same refrigeration effect, the refrigeration efficiency can be improved, and the electricity consumption can be reduced.

Description

Technical Field

[0001] The invention relates to the field of refrigeration and air conditioning, and in particular to a fresh air air conditioning unit that utilizes refrigeration return water to cool fresh air to improve refrigeration efficiency. Background Art

[0002] Nowadays, with the intensification of the greenhouse effect, my country's electricity consumption has been rising year by year. In recent years, the per capita electricity consumption has also been rising, especially in the midsummer. In order to meet the production and living needs of the majority of people, the continuous operation of air conditioners in residents and shopping malls has led to a rapid increase in electricity load. Therefore, the research on energy-saving technology of air-conditioning systems will become a new development trend.

[0003] The chilled water inlet temperature of a traditional fresh air air conditioning unit is generally 7°C. After the heat exchanger exchanges heat with the mixture of fresh air and primary return air, the chilled water temperature rises to 12°C and is sent back to the refrigeration unit to cool to 7°C before being sent back, forming a cycle. The mixture of cooled fresh air and primary return air is sent into the room, where its temperature rises and is then discharged. Part of it is discharged outdoors, and part of it returns to the air conditioning unit. The air that returns to the air conditioning unit is called primary return air. The primary return air and the newly entered fresh air are fully mixed again in the air conditioning unit, and then cooled by the heat exchanger of the air conditioning unit and sent into the room to form a cycle.

[0004] In the traditional circulation process, the high-temperature fresh air is mixed with the low-temperature primary return air. At this stage, the energy grade of the primary return air and the energy grade of the fresh air are not distinguished, resulting in the passive increase of the primary return air temperature, and then the temperature is reduced, resulting in increased energy consumption. The passive increase of the primary return air temperature means that when the cold air is circulated, the temperature of part of the cold air discharged last time (primary return air) is passively increased after mixing with the new fresh air.

[0005] Therefore, how to propose a new air blower unit that can fully utilize the cold energy in the primary return air and reduce the energy consumption and power consumption of the new air blower unit has become an urgent problem to be solved. Summary of the invention

[0006] The present invention provides a fresh air air conditioning unit which utilizes refrigerated return water to cool fresh air and improves refrigeration efficiency, so as to solve the problem in the prior art of improving air conditioning refrigeration efficiency and reducing air conditioning power consumption, thereby reducing air conditioning use costs.

[0007] In order to achieve the above-mentioned purpose, the technical solution of the present invention provides a fresh air air conditioning unit that utilizes refrigeration return water to cool fresh air to improve refrigeration efficiency, which includes: a cooling unit with a secondary mixing section, an exhaust unit, and a cooling pipeline. The surface cooling section, the secondary mixing section, the fan section, the cooling section, and the air supply section are arranged in sequence from the air inlet to the air outlet of the cooling unit. The secondary mixing section is provided with an air duct connected to the air outlet of the exhaust unit. The air duct is a three-way structure. After being discharged from the exhaust unit, one end is connected to the secondary mixing section, and the other end is connected to the outside. The secondary mixing section is configured to mix the fresh air and the return air. The cooling pipeline in the surface cooling section is close to the first inlet end of the evaporator, and the cooling pipe in the cooling section is used to receive the cold fluid sent from the evaporator. The air inlet of the exhaust unit and the air outlet of the cooling unit form an air path through the indoor space.

[0008] As a preferred embodiment of the above technical solution, preferably, an air duct connected to the air outlet of the exhaust fan unit is provided on the top of the secondary mixing section.

[0009] As a preferred embodiment of the above technical solution, preferably, the cooling pipelines in the surface cooling section and the cooling section are in the form of coils.

[0010] As a preferred embodiment of the above technical solution, preferably, the cooling pipeline is arranged in the secondary mixing section.

[0011] As a preferred embodiment of the above technical solution, preferably, the cooling unit also includes a first filter section and a second filter section. The first filter section is arranged between the air inlet and the surface cooling section of the cooling unit; the second filter section is arranged between the secondary mixing section and the fan section.

[0012] As a preferred embodiment of the above technical solution, preferably, the cooling unit also includes a humidifying section, and the humidifying section is arranged between the cooling section and the air supply section.

[0013] As a preferred embodiment of the above technical solution, preferably, the cooling circuit is specifically as follows: the second outlet end of the evaporator is connected to the second inlet end of the condenser via a first pipeline, the second outlet end of the condenser is connected to the inlet end of the cooling tower via a second pipeline, the outlet end of the cooling tower is connected to the first inlet end of the condenser via a third pipeline, and the first outlet end of the condenser is connected to the second inlet end of the evaporator via a fourth pipeline.

[0014] The technical solution of the present invention provides a fresh air air conditioning unit that utilizes refrigeration return water to cool fresh air to improve refrigeration efficiency. The surface cooling section, secondary mixing section, fan section, cooling section, and air supply section are arranged in sequence from the air inlet to the air outlet of the cooling unit. The secondary mixing section is provided with an air duct connected to the air outlet of the exhaust unit. The air duct is a three-way structure. After being discharged from the exhaust unit, one end is connected to the secondary mixing section, and the other end is connected to the outside. The cooling pipeline in the surface cooling section is close to the first inlet end of the evaporator, and the cooling pipeline in the cooling section is close to the first outlet end of the evaporator. The air inlet of the exhaust unit and the air outlet of the cooling unit form an air path through the indoor space. The evaporator, condenser and cooling tower form a cooling circuit.

[0015] The advantages of the present invention are: using low-grade refrigeration return water to first reduce the temperature of the fresh air newly flowing into the cooling unit, while further increasing the return temperature of the chilled water, and then mixing the fresh air after preliminary cooling with the primary return air, and then using the cold water flowing out of the evaporator to cool it. Using the original chilled water return water to cool the fresh air, while increasing the return temperature of the chilled water, under the same refrigeration effect, the refrigeration efficiency can be improved and the power consumption can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. 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 any creative work.

[0017] Figure 1 A schematic diagram of the structure of a fresh air air conditioning unit provided in an embodiment of the present invention that utilizes refrigeration return water to cool fresh air to improve refrigeration efficiency. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments 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.

[0019] Now combined Figure 1The equipment structure of the fresh air air conditioning unit provided by the technical solution of the present invention, which uses refrigeration return water to cool fresh air and improve refrigeration efficiency, is described. The figure includes: a cooling unit A composed of a first filtering section 1, a surface cooling section 2, a secondary mixing section 3, a second filtering section 4, a fan section 5, a cooling section 6, a humidifying section 7 and an air supply section 8, and also includes an evaporator 9, a condenser 10, a cooling tower 11, an exhaust fan unit 12 and a room 13.

[0020] An air inlet A1 is provided on one side of the cooling unit A, and an air outlet A2 is provided on the other side; the first filter section 1, the surface cooling section 2, the secondary mixing section 3, the second filter section 4, the fan section 5, the cooling section, the humidification section 7 and the air supply section 8 are arranged in sequence from the air inlet to the air outlet in the body chamber of the fresh air unit. The top of the secondary mixing section 3 is connected to the air outlet of the exhaust unit 12 via an air duct. This air duct is a three-way type. After being discharged from the exhaust unit 12, one end is connected to the secondary mixing section 3, and the other end is connected to the outside. A cooling pipeline is passed through the cooling unit A. The starting end of the cooling pipeline is connected to the first inlet end 91 of the evaporator 9, and the end is connected to the first outlet end 92 of the evaporator 9. The cooling pipe extends from one end of the bottom of the cooling unit A into the cooling section 6. The cooling pipe is in the form of a coil in the cooling section 6. After the cooling pipe extends from the cooling section 6, its form changes to a straight pipe. This straight pipe passes through the bottom of the fan section 5, the secondary filtering section, and the secondary mixing section 3 in sequence, and then enters the surface cooling section 2. At this time, the cooling pipe changes into a coil. The end of this section of the coil extends out of the bottom of the cooling unit A and the other end extends out to communicate with the first inlet end of the evaporator 9. Among them, the volume of the coil of the cooling pipe in the surface cooling section 2 and the cooling section 6 can at least fill 4 / 5 of the two refrigeration spaces respectively, so as to achieve a better refrigeration effect.

[0021] The air outlet of the cooling unit A is connected to the air supply port 131 of the room 13, and the return air port 132 of the room 13 is connected to the air inlet of the exhaust unit 12. A filter is provided on one side of the body chamber of the exhaust unit 12 near the air inlet, and a fan is provided on the other side of the filter, and the fan is directly connected to the air outlet of the exhaust unit 12. The filter is used to filter dust in the return air from the room 13 and reduce dust in the return air flowing into the secondary mixing section 3.

[0022] In order to cooperate with the cooling pipeline, the present invention also provides a cooling circuit, specifically: the second outlet end 93 of the evaporator 9 is connected to the second inlet end 101 of the condenser 10 via the first pipeline a, and the second outlet end 102 of the condenser 10 is connected to the inlet end 111 of the cooling tower 11 via the second pipeline b, thereby forming a return water passage of the cooling tower 11; the outlet end 112 of the cooling tower 11 is connected to the first inlet end 103 of the condenser 10 via the third pipeline c, and the first outlet end 104 of the condenser 10 is connected to the second inlet end 94 of the evaporator 9 via the fourth pipeline d, thereby forming a water outlet passage of the cooling tower 11.

[0023] The present invention is now described in conjunction with specific implementation scenarios:

[0024] The supply temperature of the cold water flowing out of the cooling tower 11, the condenser 10 and the evaporator 9 is 7°C. This cold water first flows into the cooling section 6 of the cooling unit A through the cooling pipeline. The 7°C cold water exchanges heat with the mixture of outdoor air and part of the indoor return air after preliminary cooling in the cooling section 6, and flows out of the cooling section 6 after heat exchange. At this time, the temperature of the 7°C cold water rises to 12°C after heat exchange. The cooling water at this time is the refrigeration return water. At this time, the refrigeration return water after the first heat exchange does not flow out directly, but continues to flow in the coil inside the unit. Further, this refrigeration return water flows into the cold coil of the surface cooling section 2 along the straight pipe, so that the 12°C refrigeration return water and the outdoor fresh air flowing in from the air inlet are preliminarily exchanged with each other, thereby reducing the temperature of the outdoor fresh air. At this time, the refrigeration return water temperature is further increased, which must be higher than 12°C after the first heat exchange, usually up to 17°C, referred to as secondary refrigeration return water. The secondary refrigeration return water flows back to the evaporator 9 and is cooled and cooled in the evaporator 9.

[0025] That is, after the outdoor fresh air enters the unit, the particles and odor in the outdoor fresh air are first coarsely filtered by the first filter section 1, and then cooled by the primary refrigeration return water with a lower energy grade, and then mixed with the indoor return air. The particles and other harmful substances in the mixed airflow are filtered again by the filter screen of the second filter section 4. The filtered mixed airflow is pressurized by the fan of the fan section 5, and then cooled again by the refrigeration water supply from the evaporator 9, and then humidified by the humidification section 7 and sent to the room 13 through the air supply section 8. Compared with the original air conditioning unit, this new unit changes the load of the fresh air unit from the original 7-12℃ cold water to the lower grade cold water of 12-17℃, which increases the supply and return water temperature difference and reduces the power consumption of the circulating water pump. More importantly, compared with the ordinary unit, this unit increases the temperature of the high-temperature heat source. According to the Carnot cycle principle, the refrigeration efficiency at this time will definitely be higher than the refrigeration efficiency when the original 12℃ return water is used, and the power consumption of the system is reduced under the same load.

[0026] Furthermore, the present invention mixes the fresh air cooled by the primary refrigeration return water and the return air from part of the room 13 in the secondary mixing section 3, and the two conduct heat transfer, thereby reducing the passive increase in the primary return air temperature caused by mixing with the higher temperature fresh air in the traditional refrigeration cycle, reducing energy consumption, and improving the utilization rate of cold air.

[0027] Furthermore, for the cooling circuit, the condenser 10 receives the heated refrigerant gas flowing out of the evaporator 9, and then condenses the gas into liquid, and then sends the cooling water heated by heat exchange into the cooling tower 11. The cooling tower 11 will cool the cooling water, and then send the cooled cooling water back to the condenser 10. The high-temperature refrigerant is cooled in the condenser 10, and the liquefied refrigerant liquid is then sent to the evaporator 9, so that the evaporator 9 can cool the secondary refrigeration return water flowing back.

[0028] In summary, the present invention uses 12°C chilled water return to cool the relatively high temperature fresh air, further increases the chilled water outlet temperature, and reduces the temperature of the fresh air, and then cools it with 7-12°C chilled water after mixing it with the primary return air. According to the refrigeration principle of the Carnot cycle, under the same other conditions, the higher the chilled water return (high temperature heat source) temperature, the higher the efficiency of the refrigerator. Therefore, by using the original chilled water return to cool the fresh air and increasing the chilled water return temperature at the same time, under the same refrigeration effect, the refrigeration efficiency can be improved and the power consumption can be reduced, thereby solving the shortcomings of the traditional fresh air air conditioning unit.

[0029] 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 replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fresh air air conditioning unit that utilizes refrigeration return water to cool fresh air and improve refrigeration efficiency, characterized in that: It includes: a cooling unit with a secondary mixing section, an exhaust fan unit, and a cooling pipeline; The surface cooling section, secondary mixing section, fan section, cooling section, and air supply section are arranged in sequence from the air inlet to the air outlet of the cooling unit; The secondary mixing section is provided with an air duct connected to the air outlet of the exhaust fan unit. The air duct is a three-way structure. After being discharged from the exhaust fan unit, one end is connected to the secondary mixing section and the other end is connected to the outside. The secondary mixing section is configured to mix the fresh air and the return air. The cooling pipeline in the surface cooling section is close to the first inlet end of the evaporator, and the cooling pipe in the cooling section is used to receive the cold fluid sent from the evaporator; The air inlet of the exhaust unit and the air outlet of the cooling unit form an air passage through the indoor space; The evaporator, the condenser, and the cooling tower constitute a cooling circuit.

2. The fresh air air conditioning unit according to claim 1, characterized in that: The top of the secondary mixing section is provided with an air duct connected to the air outlet of the exhaust fan unit.

3. The fresh air air conditioning unit according to claim 1, characterized in that: The cooling pipelines at the surface cooling section and the cooling section are both in the form of coils.

4. The fresh air air conditioning unit according to claim 1, characterized in that: The cooling pipeline is arranged in the secondary mixing section.

5. The fresh air air conditioning unit according to claim 1, characterized in that: The cooling unit further comprises a first filtering section and a second filtering section. The first filtering section is arranged between the air inlet of the cooling unit and the surface cooling section; the second filtering section is arranged between the secondary mixing section and the fan section.

6. The fresh air air conditioning unit according to claim 1, characterized in that: The cooling unit further includes a humidifying section, which is arranged between the cooling section and the air supply section.

7. The fresh air air conditioning unit according to claim 1, characterized in that: It also includes a condenser and a cooling tower. The evaporator, the condenser and the cooling tower constitute a cooling circuit. Specifically: the second outlet end of the evaporator is connected to the second inlet end of the condenser via a first pipeline, the second outlet end of the condenser is connected to the inlet end of the cooling tower via a second pipeline, the outlet end of the cooling tower is connected to the first inlet end of the condenser via a third pipeline, and the first outlet end of the condenser is connected to the second inlet end of the evaporator via a fourth pipeline.

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