Constant-temperature and constant-humidity air conditioning unit

Abstract

The utility model provides a constant-temperature and constant-humidity air conditioning unit, which comprises a compressor and an outdoor heat exchanger, and is characterized by further comprising a main four-way valve, an auxiliary four-way valve, an indoor heat exchanger and a reheating heat exchanger, the reheating heat exchanger is used for conducting heat exchange on air passing through the indoor heat exchanger again. The main four-way valve is used for adjusting the refrigerating and heating working conditions of the unit, and the auxiliary four-way valve is used for switching the access mode of the reheating heat exchanger and is connected with the outdoor heat exchanger or the indoor heat exchanger in parallel. Compared with the prior art, the reheating heat exchanger is arranged, the auxiliary four-way valve is arranged, the access mode of the reheating heat exchanger is adjusted according to different working conditions, the reheating heat exchanger is utilized to utilize waste heat of the unit, heat compensation is conducted on the unit, and the energy consumption of the unit is reduced.

Description

Technical Field

[0001] The utility model relates to the field of air-conditioning units, and more specifically, to a constant temperature and humidity air-conditioning unit. Background Art

[0002] With the development of my country's modernization process, the total energy consumption has increased year by year. More and more scholars have begun to study high-efficiency air conditioning systems, especially constant temperature and humidity air conditioning units. Constant temperature and humidity air conditioning units can be used in occasions with high temperature and humidity control accuracy, such as: electronics industry, data room, precision machinery, bioengineering, medicine and health, laboratories and high comfort environment requirements. Constant temperature and humidity air conditioning systems play an important role in the safety and comfort of the environment in these places. However, when adjusting the temperature accuracy, the existing constant temperature and humidity units often use electric heating to adjust the supply air temperature to meet the temperature requirements of the working environment, and use humidifiers for humidity compensation to offset the excessive dehumidification. However, the additional use of electric heating will consume additional electricity. Utility Model Content

[0003] The utility model aims to overcome at least one defect of the above-mentioned prior art and provide a constant temperature and humidity air-conditioning unit, which can reduce the waste heat emission of the unit by utilizing the heat condensed in the unit as a reheat energy source, and at the same time reduce the energy consumption required for humidification.

[0004] The technical solution adopted by the utility model is:

[0005] The utility model provides a constant temperature and humidity air conditioning unit, the unit comprises a compressor and an outdoor heat exchanger, the unit also comprises a main four-way valve, an auxiliary four-way valve, an indoor heat exchanger and a reheat heat exchanger;

[0006] The reheat heat exchanger is used to reheat the wind passing through the indoor heat exchanger;

[0007] Port S1 and port D1 of the main four-way valve are connected to the input end and output end of the compressor through pipelines, respectively, port E1 of the main four-way valve is connected to the output end of the indoor heat exchanger through a pipeline, and port C1 of the main four-way valve is connected to the input end of the outdoor heat exchanger through a pipeline; port C2 of the auxiliary four-way valve is connected to the input end of the compressor through a pipeline, port D2 of the auxiliary four-way valve is connected to the input end of the outdoor heat exchanger through a pipeline, port S2 of the auxiliary four-way valve is connected to port E1 of the main four-way valve through a pipeline, port E2 of the auxiliary four-way valve is connected to the output end of the reheat heat exchanger through a pipeline, and the output end of the outdoor heat exchanger is respectively connected to the input end of the reheat heat exchanger and the input end of the indoor heat exchanger through branch pipelines.

[0008] By setting up a reheat exchanger to replace the traditional electric heating supplementary heat method, and at the same time, using the auxiliary four-way valve to flexibly switch to the evaporator or condenser under the corresponding working conditions, it plays a role in increasing the indoor heat exchanger, which can increase the cooling capacity or heating capacity of the unit to achieve the purpose of rapid cooling and heating after the unit is started, and can also meet the needs when the indoor load is large.

[0009] Furthermore, a capillary tube is provided on the pipeline between the port C2 of the auxiliary four-way valve and the input end of the compressor. By providing the capillary tube, the high-pressure refrigerant flowing out of the compressor of the unit under certain working conditions can be decompressed by the capillary tube and returned to the compressor after being diverted through the auxiliary four-way valve, thereby avoiding the mixing of high-pressure refrigerant and low-pressure refrigerant at the input end of the compressor to damage the pipeline.

[0010] Furthermore, a first throttle valve is provided between the output end of the outdoor heat exchanger and the branch pipeline, a second throttle valve is provided on the branch pipeline corresponding to the indoor heat exchanger, and a third throttle valve is provided on the branch pipeline corresponding to the reheat heat exchanger.

[0011] The first throttle valve can be used to adjust the amount of refrigerant passing through the outdoor heat exchanger and the total amount of refrigerant passing through the indoor heat exchanger and the reheat heat exchanger; the second throttle valve and the third throttle valve can be used to adjust the amount of refrigerant passing through the indoor heat exchanger and the reheat heat exchanger, respectively, so as to accurately control the constant temperature of the unit and reduce the power consumption of the unit.

[0012] Furthermore, the unit further comprises an air supply passage, and the indoor heat exchanger and the reheat heat exchanger are arranged in the air supply passage;

[0013] A humidifier is also arranged in the air supply channel, and the indoor heat exchanger, the reheat heat exchanger and the humidifier are arranged in sequence in the air supply channel along the air supply direction.

[0014] A humidifier is arranged downstream of the reheat heat exchanger in the air supply direction, and the heat recovery capacity of the reheat heat exchanger can well achieve the effect of constant temperature and humidity.

[0015] Furthermore, the unit also includes an indoor fan and an outdoor fan, the indoor fan is arranged at the air outlet in the air supply channel, and the outdoor fan is arranged on one side of the outdoor heat exchanger.

[0016] The indoor fan and the outdoor fan are used to provide power for the air supply of the indoor heat exchanger and the outdoor heat exchanger. At the same time, the air volume can be adjusted by adjusting the power of the indoor fan and the outdoor fan, thereby adjusting the heat exchange effect to achieve precise constant temperature control.

[0017] Furthermore, the unit also includes a return air temperature and humidity sensor, a supply air temperature and humidity sensor, a first steam temperature sensor, a second steam temperature sensor, and an outdoor temperature sensor;

[0018] The return air temperature and humidity sensor and the supply air temperature and humidity sensor are respectively arranged at the air inlet and the air outlet in the air supply channel;

[0019] The first steam temperature sensor is arranged on the indoor heat exchanger to detect the refrigerant temperature in the indoor heat exchanger, and the second steam temperature sensor is arranged on the reheat heat exchanger to detect the refrigerant temperature in the reheat heat exchanger;

[0020] The outdoor temperature sensor is arranged on one side of the outdoor heat exchanger.

[0021] By correspondingly arranging temperature sensors at the air inlet, air outlet, indoor heat exchanger and reheat heat exchanger of the air supply channel, the corresponding air inlet temperature, air outlet temperature, and refrigerant temperature in the indoor heat exchanger and reheat heat exchanger can be better monitored, so as to achieve more precise adjustment and reduce the energy consumption of the unit while achieving a constant temperature; and, the air inlet and air outlet of the air supply channel are arranged as temperature and humidity sensors, which can further obtain the indoor humidity and then adjust the output humidity of the humidifier accordingly, so as to reduce the energy consumption of the unit while achieving a constant humidity.

[0022] Furthermore, the unit also includes an indoor temperature recovery sensor and a reheat temperature recovery sensor;

[0023] The indoor temperature recovery sensor is arranged on the pipeline between the indoor heat exchanger and the main four-way valve; the reheat temperature recovery sensor is arranged on the pipeline between the reheat heat exchanger and the auxiliary four-way valve.

[0024] By providing the indoor temperature recovery sensor and the reheat temperature recovery sensor, the temperature of the refrigerant passing through the indoor heat exchanger and the reheat heat exchanger can be obtained, thereby further achieving precise control and regulation of the unit and reducing energy consumption.

[0025] Furthermore, the unit also includes a low pressure sensor and a high pressure sensor, which are respectively arranged at the input end and the output end of the compressor. By arranging the low pressure sensor and the high pressure sensor, the hydraulic pressure of the refrigerant entering the compressor can be monitored to adjust the output power of the compressor accordingly, further realizing the precise adjustment of the unit and reducing energy consumption.

[0026] Furthermore, the unit further comprises a bypass ventilator, which is arranged between the indoor heat exchanger and the reheat heat exchanger, and is arranged in parallel with the reheat heat exchanger, and is used to adjust the air volume passing through the reheat heat exchanger. The bypass ventilator is used to adjust the air volume passing through the reheat heat exchanger, so as to further adjust the heat exchange efficiency of the reheat heat exchanger, and adjust the heat recovery efficiency, so as to achieve a better effect of constant temperature and humidity while reasonably utilizing the heat recovery amount.

[0027] Furthermore, the unit also includes a controller, which is electrically connected to each sensor and valve provided in the unit, and each heat exchanger. The controller is provided to collect data from each sensor, and then each valve can be adjusted accordingly, so as to achieve accurate adjustment of the unit and achieve the effect of reducing the energy consumption of the unit.

[0028] Compared with the prior art, the beneficial effects of the utility model are:

[0029] 1. The utility model adjusts and changes the cooling and heating working conditions of the unit by setting the main four-way valve, and sets the reheat heat exchanger to replace the traditional electric heating method for supplementary heat. The waste heat of the unit can be recycled through the reheat heat exchanger to meet the temperature requirements of the working environment, thereby reducing the overall energy consumption of the unit; in addition, the access mode of the reheat heat exchanger is adjusted and replaced by the auxiliary four-way valve, so that the reheat heat exchanger can be used as an evaporator or condenser according to different working conditions, play a role in increasing the indoor heat exchanger, and improve the cooling capacity or heating capacity of the unit, so as to achieve the purpose of rapid cooling and heating after the unit is started, and meet the needs when the indoor load is large;

[0030] 2. The utility model sets corresponding sensors in each heat exchange environment of the air supply channel and corresponding throttle valves on the pipeline of each heat exchanger. At the same time, the controller is set on the unit and the controller is electrically connected to each sensor and valve. The utility model can adjust the corresponding valves according to the specific conditions of the unit collected by each sensor, thereby achieving precise control of the unit and reducing the overall energy consumption of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural diagram of the utility model.

[0032] Figure 2 This is a refrigerant flow diagram for the dehumidification and heating mode of the utility model.

[0033] Figure 3 This is a refrigerant flow diagram for the refrigeration and dehumidification mode of the utility model.

[0034] Figure 4 This is a refrigerant flow diagram for the heating and humidification mode of the utility model.

[0035] Figure markings: compressor 1, outdoor heat exchanger 2, return air temperature and humidity sensor 3, supply air temperature and humidity sensor 4, indoor heat exchanger 5, reheat heat exchanger 6, humidifier 7, indoor fan 8, outdoor fan 9, high pressure sensor 10, low pressure sensor 11, capillary tube 12, main four-way valve 13, auxiliary four-way valve 14, second throttle valve 15, first throttle valve 16, third throttle valve 17, indoor temperature return sensor 18, reheat temperature return sensor 19, first steam temperature sensor 20, second steam temperature sensor 21, outdoor temperature sensor 22, bypass air valve 23, supply air duct 24. DETAILED DESCRIPTION

[0036] The drawings of the present invention are only used for illustrative purposes and cannot be construed as limiting the present invention. In order to better illustrate the following embodiments, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0037] Example 1

[0038] like Figure 1 As shown, this embodiment provides a constant temperature and humidity air conditioning unit, which includes a compressor 1, an outdoor heat exchanger 2, a main four-way valve 13, an auxiliary four-way valve 14, an indoor heat exchanger 5 and a reheat heat exchanger 6;

[0039] In this embodiment, the outdoor heat exchanger 2 and the indoor heat exchanger 5 can operate as an evaporator and a condenser according to different operating conditions; when operating in a cooling condition in summer, the indoor heat exchanger 5 operates as an evaporator and the outdoor heat exchanger 2 operates as a condenser; when operating in a heating condition in winter, the indoor heat exchanger 5 operates as a condenser and the outdoor heat exchanger 2 operates as an evaporator.

[0040] The compressor 1 may be configured as a variable frequency compressor 1, and the overall output of cooling capacity may be adjusted by adjusting the frequency of the compressor 1;

[0041] An air supply channel 24 is provided in the unit, and the air supply channel 24 is used to perform heat exchange on the indoor return air, so the indoor heat exchanger 5 and the reheat heat exchanger 6 are provided in the air supply channel 24. In addition, the air supply channel 24 is also used to humidify the indoor return air, so a humidifier 7 is also provided in the air supply channel 24. In this embodiment, the humidifier 7 can be set as a wet film humidifier 7. Specifically, the indoor heat exchanger 5, the reheat heat exchanger 6 and the humidifier 7 are sequentially provided in the air supply channel 24 along the air supply direction.

[0042] The reheat heat exchanger 6 is arranged downstream of the air supply direction of the indoor heat exchanger 5. When the unit needs to perform dehumidification and heat supplementation, the auxiliary four-way valve 14 can be used to adjust the reheat heat exchanger 6 in parallel with the outdoor heat exchanger 2, replacing the traditional electric heating to supplement the heat of the unit. The reheat heat exchanger 6 uses the excess waste condensation heat in the unit as a reheat energy source to reheat the air passing through the indoor heat exchanger 5. At the same time, under conventional cooling and heating conditions, the auxiliary four-way valve 14 can also be used to adjust the reheat heat exchanger 6 in parallel with the indoor heat exchanger 5.

[0043] The humidifier 7 is arranged downstream of the reheat heat exchanger 6 in the air supply direction, and is used to humidify the wind passing through the indoor heat exchanger 5 or the reheat heat exchanger 6, so that the unit can humidify the room to achieve a constant humidity effect.

[0044] The main four-way valve 13 is mainly used to realize the switching of the cooling and heating working conditions of the unit, and the auxiliary four-way valve 14 is used to adjust the access status of the reheat heat exchanger 6. Specifically, the port S1 and the port D1 of the main four-way valve 13 are respectively connected to the input end and the output end of the compressor 1 through pipelines, the port E1 of the main four-way valve 13 is connected to the output end of the indoor heat exchanger 5 through a pipeline, and the port C1 of the main four-way valve 13 is connected to the input end of the outdoor heat exchanger 2 through a pipeline; the auxiliary four-way valve 14 is connected to the input end of the outdoor heat exchanger 2 through a pipeline; Port C2 of the valve 14 is connected to the input end of the compressor 1 through a pipeline, port D2 of the auxiliary four-way valve 14 is connected to the input end of the outdoor heat exchanger 2 through a pipeline, port S2 of the auxiliary four-way valve 14 is connected to port E1 of the main four-way valve 13 through a pipeline, port E2 of the auxiliary four-way valve 14 is connected to the output end of the reheat heat exchanger 6 through a pipeline, and the output end of the outdoor heat exchanger 2 is respectively connected to the input end of the reheat heat exchanger 6 and the input end of the indoor heat exchanger 5 through branch pipelines.

[0045] A capillary tube 12 is provided on the pipeline between the port C2 of the auxiliary four-way valve 14 and the input end of the compressor 1. By providing the capillary tube 12, the high-pressure refrigerant flowing out of the compressor 1 under certain working conditions of the unit can be decompressed by the capillary tube 12 and return to the compressor 1 after being diverted through the auxiliary four-way valve 14, thereby preventing the high-pressure refrigerant and the low-pressure refrigerant from mixing at the input end of the compressor 1 and damaging the pipeline.

[0046] A first throttle valve 16 is provided between the output end of the outdoor heat exchanger 2 and the branch pipeline, a second throttle valve 15 is provided on the branch pipeline corresponding to the indoor heat exchanger 5, and a third throttle valve 17 is provided on the branch pipeline corresponding to the reheat heat exchanger 6. The first throttle valve 16 can adjust the amount of refrigerant passing through the outdoor heat exchanger 2 and the total amount of refrigerant passing through the indoor heat exchanger 5 and the reheat heat exchanger 6; the second throttle valve 15 and the third throttle valve 17 can respectively adjust the amount of refrigerant passing through the indoor heat exchanger 5 and the reheat heat exchanger 6 to accurately control the constant temperature of the unit and reduce the power consumption of the unit. At the same time, a bypass ventilator 23 is provided in the air supply duct, and the bypass ventilator 23 is provided between the indoor heat exchanger 5 and the reheat heat exchanger 6, and is provided in parallel with the reheat heat exchanger 6 to adjust the air volume passing through the reheat heat exchanger 6. The bypass air valve 23 is used to adjust the air volume passing through the reheat heat exchanger 6, so as to further adjust the heat exchange efficiency of the reheat heat exchanger 6 and adjust the heat recovery efficiency, so as to achieve a better constant temperature and humidity effect while reasonably utilizing the heat recovery amount.

[0047] Furthermore, the unit also includes an indoor fan 8 and an outdoor fan 9, the indoor fan 8 is arranged at the air outlet in the air supply channel 24, and the outdoor fan 9 is arranged on one side of the outdoor heat exchanger 2.

[0048] The unit also includes a return air temperature and humidity sensor 3, a supply air temperature and humidity sensor 4, a first steam temperature sensor 20, a second steam temperature sensor 21, and an outdoor temperature sensor 22;

[0049] The return air temperature and humidity sensor 3 and the supply air temperature and humidity sensor 4 are respectively arranged at the air inlet and the air outlet in the air supply channel 24, and are used to collect the air inlet temperature and the air outlet temperature of the air supply channel respectively;

[0050] The first steam temperature sensor 20 is arranged on the indoor heat exchanger, and is used to detect the refrigerant temperature in the indoor heat exchanger. The second steam temperature sensor 21 is arranged on the reheat heat exchanger, and is used to detect the refrigerant temperature in the reheat heat exchanger.

[0051] The outdoor temperature sensor 22 is disposed on one side of the outdoor heat exchanger 2 to collect the temperature of the outdoor environment.

[0052] The unit also includes an indoor temperature recovery sensor 18 and a reheat temperature recovery sensor 19;

[0053] The indoor temperature recovery sensor 18 is arranged on the pipeline between the indoor heat exchanger 5 and the main four-way valve 13, and collects the temperature of the refrigerant passing through the indoor heat exchanger 5; the reheat temperature recovery sensor 19 is arranged on the pipeline between the reheat heat exchanger 6 and the auxiliary four-way valve 14, and collects the temperature of the refrigerant passing through the reheat heat exchanger 6.

[0054] The unit further includes a low pressure sensor 11 and a high pressure sensor 10, which are respectively arranged at the input end and the output end of the compressor 1. By arranging the low pressure sensor 11 and the high pressure sensor 10, the hydraulic pressure of the refrigerant entering the compressor 1 can be monitored to adjust the output power of the compressor 1 accordingly, further realizing the precise adjustment of the unit and reducing energy consumption.

[0055] By setting corresponding sensors at various nodes of the air supply channel 24, indoors and outdoors, and at various parts of the pipeline, the specific operating conditions of the unit can be well monitored, and then the switching of the four-way valve of the unit, the throttling degree of each throttle valve, the operating power of the compressor 1 and the fan, and the humidification degree of the humidifier 7 are adjusted based on the specific operating conditions, so that the unit can maintain constant temperature and humidity under corresponding operating conditions and can operate with minimum energy consumption.

[0056] Correspondingly, a controller is provided in the unit, and the controller is electrically connected to the return air temperature and humidity sensor 3, the supply air temperature and humidity sensor 4, the first steam temperature sensor 20, the second steam temperature sensor 21, the outdoor temperature sensor 22, the indoor temperature return sensor 18, the reheat temperature return sensor 19, the low pressure sensor 11 and the high pressure sensor 10 to receive the data collected by each sensor; the controller is also electrically connected to the compressor 1, the indoor heat exchanger 5, the outdoor heat exchanger 2, the reheat heat exchanger 6, the main four-way valve 13, the auxiliary four-way valve 14, the first throttle valve 16, the second throttle valve 15, the third throttle valve 17, the humidifier 7, the indoor fan 8, the outdoor fan 9 and the bypass air valve 23, and is used to make corresponding adjustments to the various components of the unit to achieve constant temperature and humidity and energy-saving operation of the unit.

[0057] Example 2

[0058] Based on the constant temperature and humidity air conditioning unit described in Example 1, this embodiment provides specific operating conditions of each working condition of the unit.

[0059] In dehumidification and heating mode:

[0060] The flow direction of the refrigerant (arrow direction) is as follows Figure 2As shown, specifically, it flows from the compressor 1 to the main four-way valve 13, the port state of the main four-way valve 13 is D1 connected to C1 (indicating that the state of the main four-way valve 13 is OFF), the port state of the auxiliary four-way valve ST2 is D2 connected to E2 (indicating that the state of the auxiliary four-way valve 14 is ON), and the reheat heat exchanger 6 is connected in parallel with the outdoor heat exchanger 2. In this mode, the refrigerant condenses and absorbs heat in the reheat heat exchanger 6, and then the refrigerant in the heat exchanger passes through the third throttle valve 17 and merges with the refrigerant throttled by the first throttle valve 16, flows to the indoor heat exchanger 5 to evaporate and release heat, and then flows to the main four-way valve 13, the port state of the main four-way valve 13 is S1 connected to E1, and the refrigerant finally re-enters the compressor 1.

[0061] The outdoor heat exchanger 2 is used as a condenser, and the indoor heat exchanger 5 is used as an evaporator. In order to prevent the return air temperature from decreasing while the humidity of the indoor unit decreases, the reheat heat exchanger 6 is used as a condenser to increase the indoor supply air temperature and control the indoor return air temperature. The return air temperature is detected by the return air temperature and humidity sensor 3. When the detected return air temperature is lower than the indoor set value, the opening of the third throttle valve 17 is gradually opened. When the opening of the third throttle valve 17 is opened to the maximum, if the temperature still does not reach the lower limit of the set value, the speed of the outdoor fan 9 is reduced to maximize the recovered condensation reheat.

[0062] When the return air temperature and humidity sensor 3 detects that the return air temperature is between the upper and lower limits of the set value, the opening of the third throttle valve 17 remains unchanged;

[0063] When the return air temperature and humidity sensor 3 detects that the return air temperature is higher than the upper limit of the set value, the opening of the third throttle valve 17 is gradually reduced, and when the opening of the third throttle valve 17 is opened to the minimum; in addition, the bypass air valve 23 can also be adjusted to reduce the air volume passing through the reheat heat exchanger 6 to reduce the reheat recovery volume. If the temperature still does not drop to the upper limit of the set value, the speed of the outdoor fan 9 is increased.

[0064] In cooling and dehumidification mode:

[0065] The flow direction of refrigerant is as follows Figure 3As shown, specifically, the refrigerant flows from the compressor 1 to the main four-way valve 13, the port state of the main four-way valve 13 is D1 connected to C1, the port state of the auxiliary four-way valve is D2 connected to C2 (indicating that the state of the auxiliary four-way valve 14 is OFF), the reheat heat exchanger 6 is connected in parallel with the indoor heat exchanger 5, and the refrigerant flows into the reheat heat exchanger 6 through the third throttle valve 17. In this mode, the refrigerant evaporates and releases heat in the reheat heat exchanger 6, passes through the auxiliary four-way valve and merges with the refrigerant throttled by the second throttle valve 15, flows to the main four-way valve 13, the port state of the main four-way valve 13 is S1 connected to E1, and finally re-enters the compressor 1.

[0066] In cooling mode, when the cooling demand of the unit is large, the state of the auxiliary four-way valve 14 is set to OFF, so that the reheat heat exchanger 6 is connected in parallel with the indoor heat exchanger 5 and acts as an evaporator to increase the heat exchange area of ​​the indoor unit, thereby increasing the cooling capacity of the indoor unit;

[0067] When the reheat heat exchanger 6 is connected, the cooling demand is detected. If the cooling demand is ≤50%, the third throttle valve 17 is closed, and the refrigerant does not enter the reheat heat exchanger 6; the refrigerant previously remaining in the reheat heat exchanger 6 is drawn back to the input end of the compressor 1 through the E2-S2 passage of the auxiliary four-way valve, thereby avoiding the accumulation of refrigerant;

[0068] In this mode, the balance of the refrigerant flow of the indoor heat exchanger 5 and the reheat heat exchanger 6 is adjusted by controlling the second throttle valve 15 and the third throttle valve 17. Specifically:

[0069] The third throttle valve 17 is adjusted according to the first superheat, the first superheat = steam-out temperature T2-evaporation temperature T0, the steam-out temperature T2 is the refrigerant temperature collected by the reheating sensor 19, and the evaporation temperature T0 is the refrigerant temperature in the indoor heat exchanger collected by the first steam temperature sensor 20; the second throttle valve 15 is adjusted according to the second superheat, the second superheat = first superheat-steam-out temperature T1-evaporation temperature T0, and the steam-out temperature T1 is the refrigerant temperature collected by the indoor temperature sensor 18.

[0070] In heating and humidification conditions:

[0071] The flow direction of refrigerant is as follows Figure 4As shown, specifically, the refrigerant flows from the compressor 1 to the main four-way valve 13, the port state of the main four-way valve 13 is D1 connected to E1, the port state of the auxiliary four-way valve is S2 connected to E2, the reheat heat exchanger 6 is connected in parallel with the indoor heat exchanger 5, and in this mode, the reheat heat exchanger 6 and the indoor heat exchanger 5 are used as condensers, and the refrigerant flows into the reheat heat exchanger 6 through the outdoor heat exchanger 2. In this mode, the refrigerant condenses and absorbs heat in the reheat heat exchanger 6, and is throttled by the first throttle valve 16. After the refrigerant evaporates and absorbs heat in the outdoor heat exchanger 2, it flows to the main four-way valve 13, and the port state of the main four-way valve 13 is C1 connected to S1, and the refrigerant finally re-enters the compressor 1.

[0072] In the heating mode, when the heating demand of the unit is very large, the auxiliary four-way valve 14 is set to OFF, so that the reheat heat exchanger 6 is connected as a condenser to increase the heat exchange area of ​​the indoor unit, thereby increasing the heating capacity of the indoor unit.

[0073] When the heating demand is detected 15 minutes after the reheat heat exchanger 6 is connected, and the heating demand is ≤50%, the setting state of the auxiliary four-way valve 14 is switched to ON, the third throttle valve 17 is closed, and the refrigerant does not enter the reheat heat exchanger 6. The refrigerant previously left in the reheat heat exchanger 6 is drawn back to the input end of the compressor 1 through the C2-D2 passage of the auxiliary four-way valve 14, avoiding the accumulation of refrigerant;

[0074] In this mode, the balance of the refrigerant flow of the outdoor heat exchanger 2 and the reheat heat exchanger 6 is adjusted by controlling the first throttle valve 16 and the third throttle valve 17. Specifically:

[0075] The third throttle valve 17 is controlled according to the steam temperature T4, which is the temperature of the wind collected by the second steam temperature sensor 21;

[0076] When the steam temperature T4> the steam temperature T3, the third throttle valve 17 is adjusted down;

[0077] When the steam temperature T4∈(steam temperature T3-2°C), the third throttle valve 17 maintains the current opening, and the steam temperature T3 is the temperature of the wind collected by the first steam temperature sensor 20;

[0078] When the steaming temperature T4 is lower than the steaming temperature T3, the third throttle valve 17 is adjusted larger;

[0079] The first throttle valve 16 performs PID adjustment according to the suction superheat. Specifically, the suction superheat level is set according to the working condition of the compressor 1, and the corresponding suction temperature and the temperature of the outdoor heat exchanger 2 are obtained by the temperature sensor, and the suction superheat is calculated and compared with the suction superheat level. Based on the PID algorithm, the opening of the first throttle valve 16 is controlled so that the suction superheat meets the corresponding suction superheat level.

[0080] Obviously, the above embodiments of the utility model are only examples for clearly explaining the technical solution of the utility model, and are not intended to limit the specific implementation methods of the utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the claims of the utility model shall be included in the protection scope of the claims of the utility model.

Claims

1. A constant temperature and humidity air conditioning unit, comprising a compressor and an outdoor heat exchanger, characterized in that: The unit also includes a main four-way valve, an auxiliary four-way valve, an indoor heat exchanger and a reheat heat exchanger; The reheat heat exchanger is used to reheat the wind passing through the indoor heat exchanger; Port S1 and port D1 of the main four-way valve are connected to the input end and output end of the compressor through pipelines, respectively, port E1 of the main four-way valve is connected to the output end of the indoor heat exchanger through a pipeline, and port C1 of the main four-way valve is connected to the input end of the outdoor heat exchanger through a pipeline; port C2 of the auxiliary four-way valve is connected to the input end of the compressor through a pipeline, port D2 of the auxiliary four-way valve is connected to the input end of the outdoor heat exchanger through a pipeline, port S2 of the auxiliary four-way valve is connected to port E1 of the main four-way valve through a pipeline, port E2 of the auxiliary four-way valve is connected to the output end of the reheat heat exchanger through a pipeline, and the output end of the outdoor heat exchanger is respectively connected to the input end of the reheat heat exchanger and the input end of the indoor heat exchanger through branch pipelines.

2. A constant temperature and humidity air conditioning unit according to claim 1, characterized in that: A capillary tube is provided on the pipeline between the port C2 of the auxiliary four-way valve and the input end of the compressor.

3. A constant temperature and humidity air conditioning unit according to claim 2, characterized in that: A first throttle valve is provided between the output end of the outdoor heat exchanger and the branch pipeline, a second throttle valve is provided on the branch pipeline corresponding to the indoor heat exchanger, and a third throttle valve is provided on the branch pipeline corresponding to the reheat heat exchanger.

4. A constant temperature and humidity air conditioning unit according to claim 1, characterized in that: The unit further comprises an air supply passage, wherein the indoor heat exchanger and the reheat heat exchanger are arranged in the air supply passage; A humidifier is also arranged in the air supply channel, and the indoor heat exchanger, the reheat heat exchanger and the humidifier are arranged in sequence in the air supply channel along the air supply direction.

5. A constant temperature and humidity air conditioning unit according to claim 4, characterized in that: The unit further includes an indoor fan and an outdoor fan. The indoor fan is arranged at an air outlet in the air supply channel, and the outdoor fan is arranged at one side of the outdoor heat exchanger.

6. A constant temperature and humidity air conditioning unit according to claim 4, characterized in that: The unit also includes a return air temperature and humidity sensor, a supply air temperature and humidity sensor, a first steam temperature sensor, a second steam temperature sensor, and an outdoor temperature sensor; The return air temperature and humidity sensor and the supply air temperature and humidity sensor are respectively arranged at the air inlet and the air outlet in the air supply channel; The first steam temperature sensor is arranged on the indoor heat exchanger to detect the refrigerant temperature in the indoor heat exchanger, and the second steam temperature sensor is arranged on the reheat heat exchanger to detect the refrigerant temperature in the reheat heat exchanger; The outdoor temperature sensor is arranged on one side of the outdoor heat exchanger.

7. A constant temperature and humidity air conditioning unit according to claim 4, characterized in that: The unit also includes an indoor temperature recovery sensor and a reheat temperature recovery sensor; The indoor temperature recovery sensor is arranged on the pipeline between the indoor heat exchanger and the main four-way valve; the reheat temperature recovery sensor is arranged on the pipeline between the reheat heat exchanger and the auxiliary four-way valve.

8. A constant temperature and humidity air conditioning unit according to claim 4, characterized in that: The unit further comprises a low pressure sensor and a high pressure sensor, wherein the low pressure sensor and the high pressure sensor are respectively arranged at the input end and the output end of the compressor.

9. A constant temperature and humidity air conditioning unit according to claim 4, characterized in that: The unit further includes a bypass air valve, which is arranged between the indoor heat exchanger and the reheat heat exchanger, and is arranged in parallel with the reheat heat exchanger to adjust the air volume passing through the reheat heat exchanger.

10. A constant temperature and humidity air conditioning unit according to any one of claims 1 to 9, characterized in that: The unit also includes a controller, which is electrically connected to various sensors and valves provided in the unit, as well as various heat exchangers.

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