A heat recovery type dual cold source fresh air dehumidifier and control method thereof

Abstract

The invention discloses a heat recovery type dual cold source fresh air dehumidifier and a control method thereof. The fresh air dehumidifier comprises a frame, a fresh air channel and a return air channel are arranged in the frame, a blower is arranged in the fresh air channel, a return air fan is arranged in the return air channel, a total heat recovery device is interspersed in the fresh air channel and the return air channel, a sensible heat recovery device and an evaporator are arranged in the fresh air channel at the rear side of the total heat recovery device, and the evaporator comprises a first evaporator and a second evaporator. The invention reduces the cooling load of the indoor radiation terminal or dry coil, saves energy, and the fresh air dehumidifier still meets the indoor comfort requirements during transition seasons, especially the rainy season, etc., adopts a two-stage or three-stage cooling circuit to perform multi-stage cooling and dehumidification on the fresh air, greatly enhancing the cooling and dehumidification capacity and range of the fresh air dehumidification system, adopts two or more independent cooling circuits, which can be operated simultaneously or independently, and ensures that the air supply requirements are met while implementing the energy-saving operation of the fresh air dehumidification system.

Description

Technical Field

[0001] The present invention relates to the field of fresh air dehumidifiers, and in particular to a heat recovery type dual-cold source fresh air dehumidifier and a control method thereof. Background Art

[0002] In the field of air conditioning equipment applications, traditional air conditioners are bound to temperature and humidity. For comfort air conditioners, on the one hand, temperature and humidity are often not guaranteed at the same time. On the other hand, due to the principle defects of overcooling and reheating, it causes a huge waste of energy. The temperature and humidity control system launched by Academician Jiang Yi of Tsinghua University is more in line with the characteristics of air conditioning load. As the humidity part of temperature and humidity control, the deep dehumidification fresh air system is in a state of blooming, and various equipment manufacturers have started to develop from different angles and different ideas.

[0003] The patent name is: A fresh air unit with deep dehumidification with heat recovery (application number: 2019206420508), which discloses a fresh air dehumidifier suitable for temperature and humidity control. Although it also realizes heat recovery and dual cold source fresh air dehumidification, the supply air temperature of the system cannot be flexibly controlled. When the supply air temperature is too high, the cooling load of the indoor radiation terminal or dry coil is increased. Summary of the invention

[0004] The purpose of the present invention is to provide a heat recovery type dual cold source fresh air dehumidifier and a control method thereof in view of the deficiencies in the prior art.

[0005] To achieve the above-mentioned object, in a first aspect, the present invention provides a heat recovery type dual cold source fresh air dehumidifier, comprising a frame, a fresh air channel and a return air channel are arranged in the frame, a supply air fan is arranged in the fresh air channel, and a fresh air inlet and a supply air inlet are arranged at two ends thereof, a return air fan is arranged in the return air channel, and a return air inlet and an exhaust air inlet are arranged at two ends thereof, a total heat recovery device is interspersed in the fresh air channel and the return air channel, and it is characterized in that a sensible heat recovery device and an evaporator are arranged in the fresh air channel at the rear side of the total heat recovery device, and the fresh air is sequentially sent out from the supply air inlet through the fresh air side of the total heat recovery device, a side channel of the sensible heat recovery device, the evaporator and the other side channel of the sensible heat recovery device;

[0006] The evaporator comprises a first evaporator and a second evaporator, wherein the first evaporator is connected with a first compressor, a first condenser and a first expansion valve to form a first direct expansion system; and the second evaporator is connected with a second compressor, a second condenser and a second expansion valve to form a second direct expansion system;

[0007] It also includes a control unit, which is connected to the total heat recovery device, the first compressor, the second compressor, the first expansion valve and the second expansion valve respectively.

[0008] Furthermore, the control unit includes a control module connected to the first compressor, the second compressor, the first expansion valve and the second expansion valve respectively, and the control module is connected to a fresh air parameter measurement module, a supply air parameter measurement module and a return air parameter measurement module.

[0009] Furthermore, the first evaporator and the second evaporator are arranged in parallel or in series.

[0010] Furthermore, a surface cooler is provided between the sensible heat recovery device and the evaporator, and the surface cooler is connected to a first regulating valve, and the first regulating valve is connected to the control module.

[0011] Furthermore, the first condenser and / or the second condenser is an air-cooled condenser arranged in an outdoor unit.

[0012] Furthermore, the first condenser is an air-cooled condenser, and is arranged in the return air channel on the rear side of the total heat recovery device.

[0013] Furthermore, the second condenser is a water-cooled condenser, which is connected to a chilled water pipe. The chilled water pipe is provided with a second regulating valve, and the second regulating valve is connected to the control module.

[0014] Furthermore, an air filter is provided in the fresh air channel, and the air filter includes a primary filter, a medium filter and an electrostatic filter which are sequentially arranged along the air flow direction.

[0015] In a second aspect, the present invention further provides a control method for the above-mentioned heat recovery type dual cold source fresh air dehumidifier, comprising the following steps:

[0016] Step 1: Inputting the operating condition selection and parameter setting value instructions to the control module, wherein the parameter setting values ​​include the supply air and room temperature and absolute humidity setting values;

[0017] Step 2: The return air parameter measurement module, the fresh air parameter measurement module and the supply air parameter measurement module respectively detect the return air parameter, the fresh air parameter and the supply air parameter in real time and feed them back to the control module;

[0018] Step 3: The control module controls the operation of the air supply fan, the exhaust fan and the total heat recovery device according to the selected working conditions;

[0019] Step 4: The control module determines the fresh air parameters detected in real time by the fresh air measurement module to determine the operating states of the surface cooler and the first regulating valve;

[0020] Step 5: The control module determines the operating states of the first compressor, the second compressor and the second regulating valve according to the air supply parameter setting value in the parameter setting value and the fresh air parameter detected in real time by the fresh air measurement module;

[0021] Step 6: The control module determines the operating states of the first compressor, the second compressor and the second regulating valve according to the room parameter setting value in the parameter setting value and the return air parameter detected in real time by the return air measurement module;

[0022] Step 7: When the operating states of the first compressor, the second compressor and the second regulating valve obtained in step 5 and step 6 are inconsistent, the control module determines the operating states of the first compressor, the second compressor and the second regulating valve according to the startup priority principle.

[0023] Furthermore, the startup priority principle includes:

[0024] Priority principle 1: The start command takes precedence over the stop command.

[0025] Priority principle two: when the difference between the supply air absolute humidity content setting value and the fresh air absolute humidity content is ≤ a preset first absolute humidity content difference, the first compressor and the second compressor with the shorter cumulative running time will start running; when the difference between the supply air absolute humidity content setting value and the fresh air absolute humidity content detected in real time by the fresh air measurement module is greater than the preset first absolute humidity content difference, the first compressor and the second compressor with the longer cumulative running time will start running.

[0026] Priority principle three: when the preset second absolute humidity difference ≥ the difference between the return air absolute humidity and the room absolute humidity setting value > 0, the first compressor and the second compressor with the shorter cumulative running time will start to run; when the difference between the return air absolute humidity and the room absolute humidity setting value > the preset second absolute humidity difference, the first compressor and the second compressor with the longer cumulative running time will start to run.

[0027] Beneficial effects: First, the air supply outlet of the present invention has no reheat condenser, the air supply temperature is low, the cooling load of the indoor radiation terminal or dry coil is reduced, and energy is saved.

[0028] Second: The present invention provides an independent self-cooling source system. When the external cooling source is not running during transitional seasons, especially the rainy season, the fresh air dehumidifier can still run to meet the indoor comfort requirements.

[0029] Third: The present invention adopts a two-stage or three-stage cooling circuit to perform multi-stage cooling and dehumidification of the fresh air, which greatly enhances the cooling and dehumidification capacity and range of the fresh air dehumidification system. Moreover, the cooling and dehumidification capacity and range of the fresh air dehumidification system can be further increased through multi-stage or variable frequency control.

[0030] Fourth: The present invention adopts two or more independent cooling circuits, which can operate simultaneously or independently, ensuring that the air supply requirements are met while implementing energy-saving operation of the fresh air dehumidification system. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic structural diagram of a heat recovery type dual cold source fresh air dehumidifier according to an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments. The embodiments are implemented based on the technical solution of the present invention. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0033] like Figure 1 As shown, an embodiment of the present invention provides a heat recovery type dual cold source fresh air dehumidifier, which includes a frame 1, a fresh air channel and a return air channel are arranged in the frame 1, a supply air fan 4 is arranged in the fresh air channel, and a fresh air inlet and a supply air inlet are respectively arranged at both ends of the frame, and the supply air fan 4 introduces fresh air from the fresh air inlet into the fresh air channel, and finally sends it to the room from the supply air inlet after processing. A return air fan 14 is arranged in the return air channel, and a return air inlet and an exhaust air inlet are respectively arranged at both ends of the frame, and the return air fan 14 introduces indoor air from the return air inlet into the return air channel, and discharges it from the exhaust air inlet after recycling in the return air channel. The supply air fan 4 and the return air fan 14 can adopt fixed frequency fans, variable frequency fans or speed regulating fans. A full heat recovery device 3 is interspersed in the fresh air channel and the return air channel to recycle the indoor return air. A sensible heat recovery device 5 and an evaporator are provided in the fresh air channel at the rear side of the total heat recovery device 3, and the fresh air is sequentially sent out from the air outlet through the fresh air side of the total heat recovery device 3, a side channel of the sensible heat recovery device 5, the evaporator and the other side channel of the sensible heat recovery device 5. In the embodiment of the present invention, there are more than two evaporators. Taking two evaporators as an example, the two evaporators are respectively a first evaporator 10 and a second evaporator 9, wherein the first evaporator 10 and the second evaporator 9 can be arranged in parallel or in series. The first evaporator 10 is connected to the first compressor 2, the first condenser 13 and the first expansion valve 12 to form a first direct expansion system. The second evaporator 9 is connected to the second compressor 8, the second condenser 6 and the second expansion valve 7 to form a second direct expansion system. The embodiment of the present invention also includes a control unit, which is respectively connected to the total heat recovery device 3, the first compressor 2, the second compressor 8, the first expansion valve 12 and the second expansion valve 7 to control their operation respectively.

[0034] The control unit of the embodiment of the present invention includes a control module connected to the first compressor 2, the second compressor 8, the first expansion valve 12 and the second expansion valve 7 respectively, and the control module is connected to a fresh air parameter measurement module, a supply air parameter measurement module and a return air parameter measurement module, wherein the fresh air parameter measurement module is used to measure the temperature and humidity parameters of the fresh air entering from the fresh air inlet, and feed back the measured temperature and humidity parameters of the fresh air entering from the fresh air inlet to the control module. The supply air parameter measurement module is used to measure the temperature and humidity parameters of the fresh air sent out from the supply air inlet, and feed back the temperature and humidity parameters of the fresh air sent out from the supply air inlet to the control module. The return air parameter measurement module is used to measure the temperature and humidity parameters of the indoor return air entering from the return air inlet, and feed back the temperature and humidity parameters of the indoor return air entering from the return air inlet to the control module, and then the control module can control the operation of the dehumidifier according to the parameters fed back by the fresh air parameter measurement module, the supply air parameter measurement module and the return air parameter measurement module and the set parameters.

[0035] In order to further improve the dehumidification capacity and the flexibility of dehumidification regulation, a surface cooler 11 is also provided between the sensible heat recovery device 5 and the evaporator. The surface cooler 11 is connected to an external water source through a water supply pipe and a water return pipe. In summer, chilled water is introduced for pre-dehumidification; in winter, warm water is introduced into the surface cooler 11 for preheating the fresh air. The surface cooler 11 is connected to a first regulating valve 16, which is connected to a control module. The control module controls the opening of the first regulating valve 16, so as to adjust the pre-dehumidification effect of the surface cooler 11.

[0036] The first condenser 13 and the second condenser 6 of the embodiment of the present invention can be arranged in the outdoor unit, and can also be arranged in the fresh air unit. Specifically, when the first condenser 13 and the second condenser 6 are arranged in the outdoor unit, the first condenser 13 and the second condenser 6 both need to adopt air-cooled condensers. Preferably, the first condenser 13 and the second condenser 6 are arranged in the fresh air unit, and the first condenser 13 adopts an air-cooled condenser, and it is arranged in the return air channel on the rear side of the total heat recovery device 3 to further recycle the indoor return air. The second condenser 6 preferably adopts a water-cooled condenser, and the cooling water channel of the second condenser 6 is connected to a chilled water pipe, and the chilled water pipe is connected to an external cold source. A second regulating valve 15 is provided on the chilled water pipe, and the second regulating valve 15 is connected to the control module. The control module controls the opening of the second regulating valve 15, so as to adjust the cooling effect of the refrigerant in the second condenser 6.

[0037] In order to improve the quality of fresh air delivered into the room, an air filter may be provided in the fresh air channel, wherein the air filter comprises a primary filter, a medium filter and an electrostatic filter which are sequentially arranged along the air flow direction.

[0038] During summer working conditions, the fresh air first recovers the cold in the exhaust air through the total heat recovery device 3, the fresh air temperature decreases for the first time, and the absolute humidity content of the fresh air begins to decrease; the fresh air then enters the side channel of the sensible heat recovery device 5 through the blower 4 to recover the cold in the supply air, the fresh air temperature is reduced for the second time, the absolute humidity content of the fresh air is reduced for the second time, and the supply air temperature is increased at the same time to prevent condensation at the air supply outlet caused by too low supply air temperature; the fresh air then passes through the surface cooler 11, the fresh air temperature is reduced for the third time, and the absolute humidity content of the fresh air is reduced again; the fresh air then passes through the first evaporator 10 and the second evaporator 9, and the fresh air temperature and absolute humidity content are reduced to the target requirements; finally, the fresh air passes through the other side channel of the sensible heat recovery device 5, absorbs the heat in the fresh air, and is sent out from the air supply outlet after reheating.

[0039] The first direct expansion system is used to process the fresh air when there is no external cold source or the surface cooler 11 or the second direct expansion system cannot process the fresh air to the target requirement. The processing process is as follows: the first compressor 2 is started, and the refrigerant is compressed by the first compressor 2 and becomes high-temperature and high-pressure steam and enters the condenser 13, releasing heat to the exhaust air, and the refrigerant becomes a high-pressure liquid, and then enters the first evaporator 10 to absorb the heat in the fresh air after throttling and reducing the pressure by the first expansion valve 1, and the refrigerant becomes a low-pressure gas, and then returns to the first compressor 2 to complete the refrigeration cycle. The refrigerant absorbs the heat in the fresh air in the first evaporator 10, the temperature of the fresh air is reduced, and the moisture is condensed and precipitated, so that the fresh air can achieve the purpose of cooling and dehumidification.

[0040] The second direct expansion system is used to process the fresh air when there is no external cold source or surface cooler 11 or the first direct expansion system cannot process the fresh air to the target requirement. The processing process is as follows: the second compressor 8 is started, and the refrigerant is compressed by the second compressor 8 and becomes high-temperature and high-pressure steam and enters the water-cooled condenser 6, releasing heat to the external cold source chilled water, and the refrigerant becomes a high-pressure liquid, and then enters the second evaporator 9 after throttling and reducing the pressure by the second expansion valve 7 to absorb the heat in the fresh air, and the refrigerant becomes a low-pressure gas, and then returns to the second compressor 8 to complete the refrigeration cycle. The refrigerant absorbs the heat in the fresh air in the second evaporator 9, the temperature of the fresh air is reduced, and the moisture in the air is condensed and precipitated, so that the fresh air can achieve the purpose of cooling and dehumidification.

[0041] Under winter conditions, the control module controls the second direct expansion system to stop operating, and controls the reversing valve (not shown in the figure) in the first direct expansion system to change the flow direction of the refrigerant, so that the first evaporator 10 heats the air, and the first condenser 13 absorbs heat from the indoor return air with a higher temperature, which will not be repeated.

[0042] The control method of the heat recovery dual cold source fresh air dehumidifier of the embodiment of the present invention is as follows:

[0043] Step 1: Input the operating condition selection and parameter setting value instructions to the control module. The parameter setting values ​​include the supply air and room temperature and absolute humidity setting values.

[0044] Step 2: The return air parameter measurement module, the fresh air parameter measurement module and the supply air parameter measurement module respectively detect the return air parameters, the fresh air parameters and the supply air parameters in real time and feed them back to the control module.

[0045] Step 3: The control module controls the operation of the supply fan, exhaust fan and total heat recovery device according to the selected working conditions.

[0046] Step 4: The control module determines the operating states of the surface cooler and the first regulating valve based on the fresh air parameters detected in real time by the fresh air measurement module.

[0047] Step 5: The control module determines the operating states of the first compressor, the second compressor and the second regulating valve according to the air supply parameter setting value in the parameter setting value and the fresh air parameter detected in real time by the fresh air measurement module;

[0048] Step 6: The control module determines the operating states of the first compressor, the second compressor and the second regulating valve according to the room parameter setting value in the parameter setting value and the return air parameter detected in real time by the return air measurement module;

[0049] Step 7: When the operating states of the first compressor, the second compressor and the second regulating valve obtained in step 5 and step 6 are inconsistent, the control module determines the operating states of the first compressor, the second compressor and the second regulating valve according to the startup priority principle.

[0050] Among them, the startup priority principle can adopt the following types:

[0051] Priority principle 1: The start command takes precedence over the stop command.

[0052] Priority principle two: when the difference between the absolute humidity set value in the air supply parameter setting value and the absolute humidity content of the fresh air detected in real time by the fresh air measurement module is ≤ the preset first absolute humidity difference, the first compressor 2 and the second compressor 8 (including the second regulating valve 15) with the shorter cumulative running time will start to run; when the difference between the absolute humidity set value in the air supply parameter setting value and the absolute humidity content of the fresh air detected in real time by the fresh air measurement module is > the preset first absolute humidity difference, the first compressor 2 and the second compressor 8 (including the second regulating valve 15) with the longer cumulative running time will start to run.

[0053] Priority principle three: when the preset second absolute humidity difference ≥ the difference between the return air absolute humidity and the room absolute humidity setting value > 0, the first compressor 2 and the second compressor 8 (including the second regulating valve 15) with the shorter cumulative running time will start running; when the difference between the return air absolute humidity detected in real time by the return air measurement module and the absolute humidity setting value in the room parameter setting value > the preset second absolute humidity difference, the first compressor 2 and the second compressor 8 (including the second regulating valve 15) with the longer cumulative running time will start running.

[0054] It should be noted that the sizes of the preset first absolute moisture content difference and the preset second absolute moisture content difference need to be adjusted according to different cold water temperatures, the size of the surface cooler configuration, and the sizes of the first direct expansion system and the second direct expansion system.

[0055] The above is only a preferred embodiment of the present invention. It should be noted that for ordinary technicians in this technical field, other parts not specifically described belong to the prior art or common knowledge. Several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention.

Claims

1. A control method for a heat recovery type dual cold source fresh air dehumidifier, the dehumidifier comprising a frame, a fresh air channel and a return air channel are arranged in the frame, a supply air fan is arranged in the fresh air channel, and a fresh air inlet and a supply air inlet are arranged at both ends of the fresh air channel, a return air fan is arranged in the return air channel, and a return air inlet and an exhaust air inlet are arranged at both ends of the return air channel, a full heat recovery device is inserted in the fresh air channel and the return air channel, characterized in that: A sensible heat recovery device and an evaporator are arranged in the fresh air channel at the rear side of the total heat recovery device, and the fresh air is sequentially sent out from the air supply port through the fresh air side of the total heat recovery device, one side channel of the sensible heat recovery device, the evaporator and the other side channel of the sensible heat recovery device; The evaporator comprises a first evaporator and a second evaporator, wherein the first evaporator is connected with a first compressor, a first condenser and a first expansion valve to form a first direct expansion system; and the second evaporator is connected with a second compressor, a second condenser and a second expansion valve to form a second direct expansion system; It also includes a control unit, which is connected to the total heat recovery device, the first compressor, the second compressor, the first expansion valve and the second expansion valve respectively; The control unit comprises a control module connected to the first compressor, the second compressor, the first expansion valve and the second expansion valve respectively, and the control module is connected to a fresh air parameter measurement module, a supply air parameter measurement module and a return air parameter measurement module; A surface cooler is also provided between the sensible heat recovery device and the evaporator, and the surface cooler is connected to a first regulating valve, and the first regulating valve is connected to the control module; The method comprises the following steps: Step 1: Inputting the operating condition selection and parameter setting value instructions to the control module, wherein the parameter setting values ​​include the supply air and room temperature and absolute humidity setting values; Step 2: The return air parameter measurement module, the fresh air parameter measurement module and the supply air parameter measurement module respectively detect the return air parameter, the fresh air parameter and the supply air parameter in real time and feed them back to the control module; Step 3: The control module controls the operation of the air supply fan, the exhaust fan and the total heat recovery device according to the selected working conditions; Step 4: The control module determines the fresh air parameters detected in real time by the fresh air measurement module to determine the operating states of the surface cooler and the first regulating valve; Step 5: The control module determines the operating states of the first compressor, the second compressor and the second regulating valve according to the air supply parameter setting value in the parameter setting value and the fresh air parameter detected in real time by the fresh air measurement module; Step 6: The control module determines the operating states of the first compressor, the second compressor and the second regulating valve according to the room parameter setting value in the parameter setting value and the return air parameter detected in real time by the return air measurement module; Step 7: When the operating states of the first compressor, the second compressor and the second regulating valve obtained in step 5 and step 6 are inconsistent, the control module determines the operating states of the first compressor, the second compressor and the second regulating valve according to the startup priority principle; The startup priority principles include: Priority principle 1: The start command takes precedence over the stop command; Priority principle 2: When the difference between the supply air absolute humidity content setting value and the fresh air absolute humidity content is ≤ the preset first absolute humidity content difference, the first compressor and the second compressor with the shorter cumulative running time will start running; when the difference between the supply air absolute humidity content setting value and the fresh air absolute humidity content detected in real time by the fresh air measurement module is greater than the preset first absolute humidity content difference, the first compressor and the second compressor with the longer cumulative running time will start running; Priority principle three: when the preset second absolute humidity difference ≥ the difference between the return air absolute humidity and the room absolute humidity setting value > 0, the first compressor and the second compressor with the shorter cumulative running time will start to run; when the difference between the return air absolute humidity and the room absolute humidity setting value > the preset second absolute humidity difference, the first compressor and the second compressor with the longer cumulative running time will start to run.

2. The control method of the heat recovery type dual cold source fresh air dehumidifier according to claim 1 is characterized in that: The first evaporator and the second evaporator are arranged in parallel or in series.

3. The control method of the heat recovery type dual cold source fresh air dehumidifier according to claim 1 is characterized in that: The first condenser and / or the second condenser is an air-cooled condenser arranged in the outdoor unit.

4. The control method of the heat recovery type dual cold source fresh air dehumidifier according to claim 1 is characterized in that: The first condenser is an air-cooled condenser, and is arranged in the return air channel at the rear side of the total heat recovery device.

5. The control method of the heat recovery type dual cold source fresh air dehumidifier according to claim 1 is characterized in that: The second condenser is a water-cooled condenser, which is connected to a chilled water pipe. The chilled water pipe is provided with a second regulating valve, and the second regulating valve is connected to the control module.

6. The control method of the heat recovery type dual cold source fresh air dehumidifier according to claim 1 is characterized in that: An air filter is arranged in the fresh air channel, and the air filter comprises a primary filter, a medium filter and an electrostatic filter which are arranged in sequence along the air flow direction.

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