阅读说明：本技术 一种用于新风多级制冷的模块组合系统 (Module combination system for fresh air multistage refrigeration ) 是由 王伟 万士军 于 2021-10-21 设计创作，主要内容包括：本发明公开了一种用于新风多级制冷的模块组合系统,包括若干个模块单元,每个模块单元分别包括第一级制冷循环、第二级制冷换热器、补偿加热器,第一级制冷循环包括压缩机、蒸发器、冷凝器,每个模块单元中以第一级制冷循环中的蒸发器和冷凝器、第二级制冷换热器、补偿加热器整体作为换热组合,各个模块单元的换热组合直线分布于风道,且每个模块单元的换热组合中蒸发器、第二级制冷换热器、冷凝器、补偿加热器依次沿风向直线分布。本发明通过发挥“小压缩比”循环制冷和常规循环制冷的各自优势,用于多级制冷的空气调节领域,可实现压缩机节能20%以上。(The invention discloses a module combination system for fresh air multistage refrigeration, which comprises a plurality of module units, wherein each module unit respectively comprises a first-stage refrigeration cycle, a second-stage refrigeration heat exchanger and a compensation heater, the first-stage refrigeration cycle comprises a compressor, an evaporator and a condenser, the evaporator and the condenser in the first-stage refrigeration cycle, the second-stage refrigeration heat exchanger and the compensation heater are integrally used as a heat exchange combination in each module unit, the heat exchange combination of each module unit is linearly distributed in an air duct, and the evaporator, the second-stage refrigeration heat exchanger, the condenser and the compensation heater in the heat exchange combination of each module unit are sequentially and linearly distributed along the wind direction. The invention can save energy by more than 20 percent by exerting the respective advantages of 'small compression ratio' circulation refrigeration and conventional circulation refrigeration, and is used in the field of air conditioning of multi-stage refrigeration.)

1. The utility model provides a module combined system for multistage refrigeration of new trend which characterized in that: the system comprises a plurality of module units, wherein each module unit respectively comprises a first-stage refrigeration cycle, a second-stage refrigeration heat exchanger and a compensation heater, the first-stage refrigeration cycle comprises a loop formed by connecting a compressor, an evaporator and a condenser through pipelines, the first-stage refrigeration cycle is a vapor compression refrigeration cycle with the compression ratio not more than 1.5, and the evaporator and the condenser in the first-stage refrigeration cycle, the second-stage refrigeration heat exchanger and the compensation heater are integrally used as a heat exchange combination in each module unit;

the heat exchange combination of each module unit is arranged in the air duct and is linearly distributed along the wind direction to form a heat exchange combination linear distribution structure; the evaporator of the first-stage refrigeration cycle, the second-stage refrigeration heat exchanger, the condenser of the first-stage refrigeration cycle and the compensation heater in the heat exchange combination of each module unit are sequentially and linearly distributed along the wind direction, and one side of the evaporator in the heat exchange combination of each module unit is taken as an air inlet side and one side of the compensation heater in the heat exchange combination of each module unit is taken as an air outlet side; the air inlet side of one of the module unit heat exchange combination in the adjacent module unit faces the air outlet side of the other module unit heat exchange combination, the air inlet side of the heat exchange combination of the head end module unit is taken as the total air inlet side of the heat exchange combination linear distribution structure, the total air inlet side faces the air inlet direction of the air flue, the air outlet side of the heat exchange combination of the tail end module unit is taken as the total air outlet side of the heat exchange combination linear distribution structure, and the total air outlet side faces the air outlet direction of the air flue.

2. The modular combined system for fresh air multistage refrigeration as claimed in claim 1, wherein: in each module unit, the temperature difference between the air temperature after passing through the evaporator in the first-stage refrigeration cycle and the air temperature after passing through the second-stage refrigeration heat exchanger is not less than 20 ℃.

3. The modular combined system for fresh air multistage refrigeration as claimed in claim 1, wherein: in each module unit, the refrigerating capacity of the evaporator in the first-stage refrigerating cycle is equal to that of the second-stage refrigerating heat exchanger.

4. The modular combined system for fresh air multistage refrigeration as claimed in claim 1, wherein: in each module unit, an evaporator and a condenser in the first-stage refrigeration cycle are respectively of a fin type.

5. The modular combined system for fresh air multistage refrigeration as claimed in claim 1, wherein: in each modular unit, the second stage refrigeration heat exchanger is an evaporator in a conventional vapor compression refrigeration cycle, or a surface cooler using cold water.

6. The modular combined system for fresh air multistage refrigeration as claimed in claim 1, wherein: in each module unit, the compensating heater is a silicon controlled fin electric heater.

7. The modular combined system for fresh air multistage refrigeration as claimed in claim 1, wherein: the first stage refrigeration cycle in each modular unit also includes a throttling element or capillary tube connected between the evaporator and the condenser.

8. The modular combined system for fresh air multistage refrigeration as claimed in claim 1, wherein: the heat exchange combination air inlet side areas of all the module units are equivalent.

9. The modular combined system for fresh air multistage refrigeration as claimed in claim 1, wherein: the air inlet of the centrifugal fan faces the air inlet direction in the air channel, and the air outlet of the centrifugal fan faces the air outlet direction in the air channel.

Technical Field

The invention relates to the field of fresh air conditioning systems, in particular to a module combination system for fresh air multistage refrigeration.

Background

With the rapid development of electronic equipment and equipment, people have higher and higher requirements on the temperature and humidity of some special spaces. For example, in a high-temperature and high-humidity area, a cooled object is far away from an equipment security area, and then, quantitative low-temperature air (such as 15-25 ℃ and relative humidity less than or equal to 50%) after cooling and filtering can be directly sent into a cooled object space only through one or more lengthened air pipes, so that the environment security is realized, generally, the air conditioner has no return air pipe, so that high-temperature and high-humidity (such as dry-bulb temperature of 40 ℃ and relative humidity of 60%) fresh air needs to be subjected to multi-stage cooling treatment. At present, most of common fresh air conditioning equipment in the market adopts a 2-level or 3-level refrigeration system, namely, hot air is cooled by a 2-level or 3-level evaporator, and due to the problems of dehumidification and frosting, common manufacturers add heaters in front of and behind each level of evaporator to improve relative humidity, realize gradient cooling and ensure that the final level meets the required temperature and humidity requirements. For example, some of the disclosed multi-stage refrigeration, dehumidification and temperature control devices adopt a 3-stage evaporator and a 4-stage electric heater to meet the requirements of the temperature and the humidity of the final-stage air supply, but do not utilize the condensation heat and completely adopt electric heating compensation, such air conditioners are often large in power consumption and not energy-saving, and when the air conditioners are used for dealing with more normal-temperature and high-humidity working conditions, the stable output of the temperature and humidity is often difficult to realize due to few stages, and the special humidity is difficult to control.

In the industry, in order to realize the dehumidification function, besides the dehumidification by adopting the vapor compression refrigeration, the modes of rotating wheel dehumidification, solid adsorption dehumidification and the like are also adopted, but the defects of the methods also exist, such as the air tightness and space problems of rotating wheel dehumidification, and the problems of material and adsorption and desorption conversion and the like need to be solved in the heat exchanger of solid adsorption dehumidification. Therefore, on the basis of the original vapor compression refrigeration, the dehumidification, temperature rise and humidity reduction capabilities of the system can not be improved by introducing the high-efficiency small-compression-ratio vapor compressor refrigeration cycle, and meanwhile, the condenser in the small-compression-ratio vapor compressor refrigeration cycle is placed in the air duct for partial thermal compensation, so that the system is worthy of research.

Disclosure of Invention

The invention aims to provide a module combination system for fresh air multistage refrigeration, which solves the problem that the temperature and humidity balance is difficult to be considered in a fresh air conditioning system with a multistage evaporator arranged in an air duct in the prior art.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a module combination system for fresh air multistage refrigeration comprises a plurality of module units, wherein each module unit comprises a first-stage refrigeration cycle, a second-stage refrigeration heat exchanger and a compensation heater, the first-stage refrigeration cycle comprises a loop formed by connecting a compressor, an evaporator and a condenser through pipelines, the first-stage refrigeration cycle is a vapor compression refrigeration cycle with the compression ratio not more than 1.5, and the evaporator and the condenser in the first-stage refrigeration cycle, the second-stage refrigeration heat exchanger and the compensation heater are integrally used as a heat exchange combination in each module unit;

the heat exchange combination of each module unit is arranged in the air duct and is linearly distributed along the wind direction to form a heat exchange combination linear distribution structure; the evaporator of the first-stage refrigeration cycle, the second-stage refrigeration heat exchanger, the condenser of the first-stage refrigeration cycle and the compensation heater in the heat exchange combination of each module unit are sequentially and linearly distributed along the wind direction, and one side of the evaporator in the heat exchange combination of each module unit is taken as an air inlet side and one side of the compensation heater in the heat exchange combination of each module unit is taken as an air outlet side; the air inlet side of one of the module unit heat exchange combination in the adjacent module unit faces the air outlet side of the other module unit heat exchange combination, the air inlet side of the heat exchange combination of the head end module unit is taken as the total air inlet side of the heat exchange combination linear distribution structure, the total air inlet side faces the air inlet direction of the air flue, the air outlet side of the heat exchange combination of the tail end module unit is taken as the total air outlet side of the heat exchange combination linear distribution structure, and the total air outlet side faces the air outlet direction of the air flue.

Furthermore, in each module unit, the temperature difference between the air temperature after passing through the evaporator in the first-stage refrigeration cycle and the air temperature after passing through the second-stage refrigeration heat exchanger is not less than 20 ℃.

Furthermore, in each module unit, the refrigerating capacity of the evaporator in the first-stage refrigerating cycle is equal to that of the second-stage refrigerating heat exchanger.

Furthermore, in each module unit, an evaporator and a condenser in the first-stage refrigeration cycle are respectively of a fin type.

Further, in each modular unit, the second-stage refrigeration heat exchanger is an evaporator in a conventional vapor compression refrigeration cycle, or a surface cooler using cold water.

Furthermore, in each module unit, the compensation heater is a silicon controlled fin electric heater.

Furthermore, the first stage refrigeration cycle in each modular unit further comprises a throttling element or a capillary tube, and the throttling element or the capillary tube is connected between the evaporator and the condenser.

Furthermore, the heat exchange combination air inlet side areas of all the module units are equivalent.

Furthermore, the air conditioner also comprises a centrifugal fan, wherein the centrifugal fan is arranged between any two module units in the air duct air inlet, the air duct air outlet or the air duct, the air inlet of the centrifugal fan faces the air-up direction in the air duct, and the air outlet of the centrifugal fan faces the air-down direction in the air duct.

The invention utilizes the refrigeration cycle of a vapor compressor with a small compression ratio as the first-stage refrigeration cycle, on one hand, in the fresh air multi-stage refrigeration, the dehumidification problem of humid air is mainly solved, and usually, heat compensation is added after each stage of refrigeration so as to keep the system to normally work; on the other hand, the refrigeration cycle of the steam compressor with the small compression ratio is equivalent to the heat pipe cycle with a power source in a certain sense, and as the air flows into the evaporator and the condenser through the secondary refrigeration, the air has larger temperature difference, the larger the temperature difference is, the higher the energy efficiency ratio of the refrigeration cycle is, and the energy efficiency ratio is at least improved by more than 2.5 times compared with the traditional refrigeration cycle of the steam compressor.

In the invention, the air flow in the air duct can be promoted by the centrifugal fan. The compressor in the first stage of refrigeration cycle in each module unit is gaseous return air, and an exhaust port of the compressor returns to a return air port of the compressor after being sequentially connected with the condenser, the throttling element and the evaporator through pipelines.

Each module unit can be continuously and linearly combined according to refrigeration requirements to form multi-stage refrigeration, each module unit is equivalent to optimized 2-stage refrigeration, and if the original 3-stage compression refrigeration air conditioning equipment is adopted, 2 groups of module units can be used for replacing the module units. If 3 modular units are arranged, 6-level refrigeration can be formed, and different modular units or backup can be started according to different control requirements.

In each module unit, the temperature difference between the air temperature after passing through the evaporator and the air temperature after passing through the second-stage refrigeration heat exchanger is not less than 20 ℃, which is the premise of achieving the high energy efficiency ratio by the 'small compression ratio' circulation, and the electricity can be saved by more than 20% compared with a first-stage refrigeration compressor. And then the air is sent out to the downwind module unit after passing through the condenser and the compensating heater, and finally sent out to the air channel in the process.

The throttling element of the first-stage refrigeration cycle of each module unit can automatically adjust the opening degree by detecting the pressure or the pressure difference between the two ends of the throttling element, thereby realizing the requirement of small compression ratio, and also can be replaced by a fixed flow port such as a capillary tube.

The compensation heater in each module unit is used for compensating when the condenser of the first-stage refrigeration cycle fails to heat the air to the required temperature, and a silicon controlled fin electric heater can be particularly used.

The centrifugal fan is selected according to the required parameters of air quantity, air pressure, air resistance and the like, and can be arranged at the air inlet and the air outlet of the air duct or in the middle of the air duct without limitation.

Compared with the prior art, the invention has the advantages that:

1. the invention can save energy by more than 20% by using the modular unit formed by 'small compression ratio' circulating refrigeration.

2. Each module unit of the invention has 2-stage refrigeration and dehumidification, the air outlet temperature is more stable, and the condensation temperature of the first-stage refrigeration cycle is low, thus avoiding the risk of overloading the compressor.

3. The invention adopts a modular design idea, and is convenient for product design.

4. The invention has the advantages of ingenious and concise principle and easy realization.

Drawings

FIG. 1 is a schematic diagram of the system architecture of the present invention.

Detailed Description

The invention is further illustrated with reference to the following figures and examples.

As shown in FIG. 1, in FIG. 1Indicating the direction of air flow within the air duct,indicating the primary refrigerant flow direction of modular unit a,indicating the secondary refrigerant flow direction of modular unit a. The invention relates to a module combination system for fresh air multistage refrigeration, which comprises a centrifugal fan 100 and a plurality of module units A, wherein the module units A have the same structure and respectively comprise a first-stage refrigeration cycle, a second-stage refrigeration heat exchanger 2 and a compensation heater 5. In each module unit A, the first-stage refrigeration cycle is a vapor compression refrigeration cycle with a compression ratio not greater than 1.5 and at least comprises a compressor 3, a condenser 4, a throttling element 6 and an evaporator 1, the compressor 3 in the first-stage refrigeration cycle is gaseous return air, an exhaust port of the compressor 3 is sequentially connected with the condenser 4, the throttling element 6 and the evaporator 1 through pipelines and then returns to a return air port of the compressor 3, and the evaporator 1 and the condenser 4 are both fin type heat exchangers. In each modular unit a, the second-stage refrigeration heat exchanger 2 can be an evaporator in a conventional vapor compression refrigeration cycle or a surface cooler using cold water, and the refrigeration capacities of the evaporator 1 and the second-stage refrigeration heat exchanger 2 of the first-stage refrigeration cycle are kept equivalent. The throttling element 6 can automatically adjust the opening degree by detecting the pressure or the pressure difference between two ends of the throttling element, thereby realizing the requirement of small compression ratio, and can also be replaced by a fixed flow port such as a capillary tube.

In each module unit A, an evaporator 1 of a first-stage refrigeration cycle, a second-stage refrigeration heat exchanger 2, a condenser 4 of the first-stage refrigeration cycle and a compensation heater 5 jointly form a heat exchange combination. In the heat exchange combination, one side of the evaporator 1 is used as an air inlet side, one side of the compensation heater 5 is used as an air outlet side, and the area of the air inlet side of each module unit A at least used for facing the wind is kept equivalent. The heat exchange combination of each module unit A is arranged in the air duct and is linearly distributed along the wind direction, and the heat exchange combination air inlet side of the module unit at the downwind position in the adjacent module unit A faces the heat exchange combination air outlet side of the module unit at the upwind position. The heat exchange combination air inlet side of the head end module unit A is used as a total air inlet side, the total air inlet side faces the air inlet direction of the air duct, the heat exchange combination air outlet side of the tail end module unit A is used as a total air outlet side, and the total air outlet side faces the air outlet direction of the air duct.

According to the invention, the module units A can be continuously combined to form multi-stage refrigeration according to refrigeration requirements, as shown in figure 1, 3 module units A are connected in series to form 6-stage refrigeration, and different module units A are started or used for backup according to different control requirements.

In each module unit A, air passes through the evaporator 1, the second-stage refrigeration heat exchanger 2, the condenser 4 and the compensation heater 5 in sequence and then is sent to the downwind module unit A, the temperature difference between the air passing through the evaporator 1 and the air passing through the second-stage refrigeration heat exchanger 2 is not less than 20 ℃, and the compensation heater 5 is used for compensating when the condenser 4 of the first-stage refrigeration cycle fails to heat the air to the required temperature, and a silicon controlled fin electric heater and the like can be adopted. Air entering from the air duct air inlet sequentially passes through the heat exchange combination of each module unit A and then is sent out from the air duct air outlet.

The centrifugal fan 100 is arranged at the air inlet of the air duct, or the air outlet of the air duct, or between any two adjacent module units A, the air inlet of the centrifugal fan 100 faces the upwind direction, the air outlet faces the downwind direction, the type of the centrifugal fan 100 is selected according to the required parameters such as the air quantity, the air pressure and the air resistance, and the air in the air duct is accelerated to flow by the centrifugal fan 100.

The invention is further illustrated as follows:

in order to improve the energy efficiency ratio of the system, the temperature difference of cooled air after passing through the evaporator 1 and the second-stage refrigeration heat exchanger 2 is not less than 20 ℃, which is the premise of realizing the 'small compression ratio' circulation to obtain the high energy efficiency ratio. For example, the ambient dry bulb temperature is 40 deg.C, the relative humidity is 60%, and the moisture content isQuantity d₁28.79g/kg, enthalpy value h₁114.5 kj/kg; the temperature after passing through the evaporator was 31 ℃, the relative humidity was 77%, and the moisture content d₂22.27g/kg, enthalpy value h₂88.25 kj/kg; the temperature after passing through the second-stage refrigeration heat exchanger 2 is 20 ℃, the relative humidity is 96 percent, and the moisture content d is₃19.38g/kg, enthalpy value h₃56.36kj/kg, the temperature after passing through the condenser 4 was 23 ℃ and the relative humidity was 81%. The air quantity of the centrifugal fan is uniformly taken to be 2000m³H, average density of air ρ =1.2kg/m³。

R134a refrigerant is adopted, the condensing temperature of the condenser 4 is 25 ℃, the supercooling degree is 0 ℃, the evaporating temperature of the evaporator 1 is 20 ℃, the superheat degree is 5 ℃, the corresponding absolute condensing pressure and evaporating pressure are respectively 6.66bar and 5.72bar, and the compression ratio is 1.16. Looking up the thermodynamic cycle diagram of R134a, it can be known that the enthalpy difference V of unit refrigerating capacity₁About 179kj/kg, unit theoretical compression work enthalpy difference V_{Row board}When the refrigerant is approximately equal to 3.5kj/kg, the theoretical refrigeration coefficient EER is equal to V₁/V_{Row board}179/3.5 ≈ 51. Through relevant verification, when the temperature difference is 20 ℃, the EER of the compressor is actually measured to be at least more than 8.0.

By adopting the invention, the first-stage evaporator refrigerates:

refrigerating capacity Q₁＝G∙ρ∙ (h₁-h₂)/3600=2000×1.2×(114.5-88.25)/3600=17.5kW，

Moisture removal amount S₁＝G∙ρ∙ (d₁-d₂)= 2000×1.2×(28.79-22.27)=15648 g/h。

Refrigerating by a second-stage refrigerating heat exchanger:

refrigerating capacity Q₂＝G∙ρ∙ (h₂-h₃)/3600=2000×1.2×(88.25-56.36)/3600=21.26kW，

Moisture removal amount S₂＝G∙ρ∙ (d₂-d₃)= 2000×1.2×(22.27-19.38)=6936 g/h。

The contrast adopts conventional primary refrigeration, and the wind taking-out states are consistent, then

Total cooling capacity Q-G ∙ ρ ∙ (h)₁-h₃)/3600=2000×1.2×(114.5-56.36)/3600=38.76kW，

Total moisture removal amount S G ∙ ρ ∙ (d)₁-d₃)=2000×1.2×(28.79-19.38)=22584 g/h。

Meaning that theoretically, the total refrigerating capacity needs 38.76W when the one-stage compressor is adopted for refrigeration, the energy efficiency is 3.0, the consumed power of the compressor is 12.92kW, and the theoretical discharge capacity of the compressor is about 47.0m³/h。

In the invention, when the EER of the compressor of the first stage refrigeration is taken as 8.0, the corresponding power is 2.19kW, and the theoretical discharge capacity of the compressor is about 14.5m³H; taking the EER of the compressor for the second stage refrigeration as 3.0, the corresponding power is 7.09kW, and the theoretical discharge capacity of the compressor is about 25.8m³H; the total displacement of the two-stage compressor is reduced by 14.3% compared with the one-stage refrigeration displacement; the total power consumption of the two-stage compressor is 9.28kW, compared with the power consumption of the compressor of the first-stage refrigeration, the power is saved by about 28.2 percent.

The original first-stage compressor is divided into 2 stages, and if the original 3-stage compression refrigeration air conditioner is adopted, 2 groups of module units A can be completely used for substitution; if 3 sets of module unit A are used at this time, 1 set of module unit A can be used as a backup.

The above-described embodiments are only preferred embodiments of the present invention, but the present invention is not limited to the above-described embodiments, and any obvious modifications thereof without departing from the principle of the present invention will be apparent to those skilled in the art within the spirit of the present invention and the scope of the appended claims.