An open and close integrated drying machine

Abstract

The present invention relates to an integrated open and close dryer, comprising: a heat pump system, which includes a compressor, a flow switching device, an indoor condenser, an indoor evaporator, an outdoor heat exchanger, a first throttling device and a second throttling device connected by a refrigerant pipeline; the outdoor heat exchanger includes a first outdoor heat exchanger and a second outdoor heat exchanger connected in parallel; the first outdoor heat exchanger and the second outdoor heat exchanger are respectively connected to an open and close valve between the two ends of one side of the second throttling device and a one-way valve between the two ends of the other side; the integrated open and close dryer also includes: a processing unit, which is configured to control the dryer to enter a heating and drying mode, a rapid temperature rise dehumidification mode, a temperature rise dehumidification mode and a steady temperature dehumidification mode according to the dry-bulb temperature difference and the wet-bulb temperature difference in the drying room. The present invention can avoid the problem of too much refrigerant accumulating in the outdoor heat exchanger in the steady temperature dehumidification mode, resulting in a small amount of circulating refrigerant.

Description

Technical Field

[0001] The invention relates to the technical field of air source heat pump drying, and in particular to an open and close integrated drying machine. Background Art

[0002] With the continuous advancement of the coal-to-electricity process, air source heat pump dryers have gradually become the mainstream equipment for coal-to-electricity conversion, for example, they can be used to dry tobacco.

[0003] The existing open and close integrated dryer can use three heat exchangers: indoor condenser, indoor evaporator and outdoor heat exchanger to open or close the drying room, and switch between the two modes according to the control conditions. For example, the tobacco drying process needs to go through multiple steady temperature sections and temperature rising sections. In different steady temperature sections and temperature rising sections, the wet bulb temperature in the drying room needs to be controlled. In the steady temperature section, the tobacco drying standard requires that the dry bulb temperature in the drying room be controlled at ±1°C, otherwise it will affect the drying quality.

[0004] Therefore, during the drying process, it is necessary to switch between the open mode and the closed mode according to the control conditions. This control method frequently switches between the two switching modes, resulting in frequent starts and stops of the compressor, valve switching, and fan starts and stops, which affects the service life of the dryer and is not energy-saving.

[0005] Figure 1 and Figure 2 The control cycle schematic diagram of the existing dryer is shown; Figure 1 , a refrigerant flow diagram in the heating and temperature-raising mode is shown (see arrows). In the heating and temperature-raising mode, the four-way valve 170 is powered off, and the refrigerant discharged from the compressor 110 passes through the indoor condenser 120 for heat exchange, and a part of it passes through the throttling device 130 to enter the indoor evaporator 120, and a part of it passes through the throttling device 150 to enter the outdoor heat exchanger 140. The refrigerant after heat exchange in the indoor evaporator 120 flows back to the compressor 160, and the refrigerant after heat exchange in the outdoor heat exchanger 140 flows back to the compressor 160 through the four-way valve 170; Figure 2 The refrigerant flow diagram in the steady temperature dehumidification mode is shown (see the arrows). In the steady temperature dehumidification mode, the four-way valve 170 is powered on, and part of the refrigerant discharged from the compressor 160 flows into the indoor condenser 110, and part flows into the outdoor heat exchanger 140 through the four-way valve 170. The refrigerant after heat exchange in the outdoor heat exchanger 140 is throttled by the throttling device 150 and merges with the refrigerant after heat exchange in the indoor condenser 110, and then throttled by the throttling device 130 and enters the indoor evaporator 120 for heat exchange, and then the heat-exchanged refrigerant flows back to the compressor 160.

[0006] In the steady temperature dehumidification mode, due to the large temperature difference between the drying room and the outside, the refrigerant entering the outdoor heat exchanger 140 is quickly condensed into liquid, the flow rate and flow resistance increase, resulting in a decrease in the amount of circulating refrigerant in the system, the suction and exhaust temperatures of the compressor 160 rise rapidly, and the suction pressure is too low, causing the unit to shut down. Summary of the invention

[0007] The present invention provides an integrated open and close dryer, which can divide an outdoor heat exchanger into a first outdoor heat exchanger and a second outdoor heat exchanger, and designs the heat exchange area ratio between the first outdoor heat exchanger and the indoor condenser, as well as the heat exchange area ratio between the second outdoor heat exchanger and the indoor evaporator, so that when the dryer is in the heating mode, it can also avoid the problem of too much refrigerant accumulating in the outdoor heat exchanger and causing a small amount of circulating refrigerant in the stable temperature dehumidification mode, thereby ensuring reliable operation of the unit.

[0008] The present application provides an opening and closing integrated drying machine, comprising:

[0009] A heat pump system, comprising a compressor, a flow switching device, an indoor condenser, an indoor evaporator, an outdoor heat exchanger, a first throttling device and a second throttling device connected by a refrigerant pipeline; the refrigerant after heat exchange in the indoor condenser flows into the indoor evaporator through the first throttling device, and flows into the outdoor heat exchanger through the second throttling device; the flow switching device is used to switch the refrigerant flow path so that the outdoor heat exchanger serves as a condenser and an evaporator;

[0010] The outdoor heat exchanger comprises a first outdoor heat exchanger and a second outdoor heat exchanger connected in parallel; the first outdoor heat exchanger and the second outdoor heat exchanger are respectively connected to the second throttling device, and the two ends on one side are connected to the on-off valve, and the two ends on the other side are connected to the one-way valve, which is used to lead out the refrigerant from the second outdoor heat exchanger in one direction;

[0011] a processing unit configured to control the dryer to enter a heating and drying mode, a rapid heating and dehumidification mode, a heating and dehumidification mode, and a steady temperature and dehumidification mode according to a dry-bulb temperature difference between a dry-bulb temperature in the drying chamber and a set dry-bulb temperature, and a wet-bulb temperature difference between a wet-bulb temperature in the drying chamber and a set wet-bulb temperature;

[0012] In the heating and drying mode, the compressor is started, the first throttling device is closed, the on-off valve and the second throttling device are opened, and the flow path switching device switches the flow path so that the outdoor heat exchanger serves as an evaporator;

[0013] In the rapid heating and dehumidification mode, the compressor is started, the first throttling device, the second throttling device and the on-off valve are turned on, and the flow path switching device switches the flow path so that the outdoor heat exchanger acts as an evaporator;

[0014] In the heating and dehumidification mode, the compressor is started, the second throttling device is closed, and the first throttling device is opened;

[0015] In the steady-temperature dehumidification mode, the compressor is started, the on-off valve is closed, the first throttling device and the second throttling device are opened, and the flow path switching device switches the flow path so that the first outdoor heat exchanger serves as a condenser.

[0016] The on-off integrated dryer involved in the present application divides the original outdoor heat exchanger into a first outdoor heat exchanger and a second outdoor heat exchanger, and the first outdoor heat exchanger and the second outdoor heat exchanger are respectively connected to an on-off valve between the two ends of one side of the second throttling device and a one-way valve between the two ends of the other side, which is used to unidirectionally lead out the refrigerant from the second outdoor heat exchanger. In this way, by controlling the dry-bulb temperature difference and the wet-bulb temperature difference, the first throttling device, the second throttling device, the flow switching device and the on-off valve are controlled to realize multiple mode conversions and meet various needs of the drying room.

[0017] And since the outdoor heat exchanger is divided into a first outdoor heat exchanger and a second outdoor heat exchanger, in the steady temperature dehumidification mode, the first outdoor heat exchanger acts as a condenser. Since its heat exchange area is smaller than the heat exchange area of ​​the outdoor heat exchanger, the amount of refrigerant flowing into the first outdoor heat exchanger is relatively small, which can ensure sufficient refrigerant circulation and thus ensure the normal operation of the unit, improve the reliability of the unit, and at the same time do not affect the heating and drying mode and the rapid heating and defrosting mode. The temperature rise.

[0018] In some embodiments of the present application, the heat exchange areas of the first outdoor heat exchanger and the second outdoor heat exchanger are determined by calculation to ensure that the unit can discharge excess heat from the drying chamber in the steady temperature dehumidification mode without accumulating too much refrigerant in the outdoor heat exchanger. Therefore, the ratio of the heat exchange areas of the first outdoor heat exchanger and the indoor condenser is required to be in the range of 0.2 to 0.5, which is used to control the amount of refrigerant entering the first outdoor heat exchanger in the steady temperature dehumidification mode.

[0019] In some embodiments of the present application, the ratio of the heat exchange area of ​​the second outdoor heat exchanger to the indoor evaporator is in the range of 0.2 to 1, which is used to control the amount of heat absorbed by the second outdoor heat exchanger from the external environment in the heating and drying mode and the heating and dehumidification mode.

[0020] In some embodiments of the present application, according to the dry-bulb temperature difference and the wet-bulb temperature difference, the dryer is controlled to enter a heating and drying mode, a rapid heating and dehumidification mode, a heating and dehumidification mode, and a steady temperature and dehumidification mode, specifically:

[0021] When the dry-bulb temperature difference reaches below a first dry-bulb temperature threshold, and the wet-bulb temperature difference reaches below a first wet-bulb temperature threshold, controlling the dryer to enter a heating and drying mode;

[0022] When the dry-bulb temperature difference reaches above the first dry-bulb temperature threshold and reaches below the second dry-bulb temperature threshold, or reaches above the second dry-bulb temperature threshold and the wet-bulb temperature difference reaches below the first wet-bulb temperature threshold, the compressor stops and only the indoor fan is kept turned on;

[0023] When the dry-bulb temperature difference reaches below a first dry-bulb temperature threshold and the wet-bulb temperature difference reaches above a first wet-bulb temperature threshold, controlling the dryer to enter a rapid heating and dehumidification mode;

[0024] When the dry-bulb temperature difference reaches above the first dry-bulb temperature threshold and below the second dry-bulb temperature threshold, or reaches above the second dry-bulb temperature threshold, and the wet-bulb temperature difference reaches above the first wet-bulb temperature threshold and below the second wet-bulb temperature threshold, the compressor stops, and only the indoor fan remains turned on;

[0025] When the dry-bulb temperature difference reaches above the first dry-bulb temperature threshold and below the second dry-bulb temperature threshold, and the wet-bulb temperature difference reaches above the second wet-bulb temperature threshold, controlling the dryer to enter a heating and dehumidification mode;

[0026] When the dry-bulb temperature difference reaches above a second dry-bulb temperature threshold, and the wet-bulb temperature difference reaches above a second wet-bulb temperature threshold, controlling the dryer to enter a steady-temperature dehumidification mode;

[0027] The first dry-bulb temperature threshold is smaller than the second dry-bulb temperature threshold, and the first wet-bulb temperature threshold is smaller than the second wet-bulb temperature threshold.

[0028] In some embodiments of the present application, in the heating and drying mode, the refrigerant discharged from the compressor flows out after heat exchange through the indoor condenser, flows into the outdoor heat exchanger for heat exchange after throttling through the second throttling device, and flows back to the compressor through the flow switching device.

[0029] The indoor condenser is used as a condenser and the outdoor heat exchanger is used as an evaporator to achieve indoor heating and drying.

[0030] In the rapid heating and dehumidification mode, the refrigerant discharged from the compressor passes through the indoor condenser for heat exchange and then flows out. Part of the refrigerant passes through the first throttling device and enters the indoor evaporator, and part passes through the second throttling device and enters the outdoor heat exchanger. The refrigerant after heat exchange from the indoor evaporator merges with the refrigerant flowing out from the outdoor heat exchanger through the flow switching device and flows back to the compressor.

[0031] The indoor condenser is used as a condenser, the indoor evaporator is used as an evaporator, and the outdoor heat exchanger is used as an evaporator. While heating and drying the drying room, the indoor evaporator can also be used to dehumidify the air flow in the drying room.

[0032] In the heating and dehumidification mode, the refrigerant discharged from the compressor flows into the indoor evaporator for heat exchange after being throttled by the first throttling device, and the refrigerant after heat exchange flows back to the compressor.

[0033] The indoor condenser is used as a condenser and the indoor evaporator is used as an evaporator. Although the indoor evaporator can dehumidify the airflow in the drying room, the dehumidified air will still be heated up by heat exchange with the indoor condenser. At this time, there is no heat exchange between the drying room and the dryer and the external environment. The temperature in the drying room will still gradually rise, realizing drying and dehumidification.

[0034] In the steady temperature dehumidification mode, a part of the refrigerant discharged from the compressor enters the indoor condenser for heat exchange, and a part of the refrigerant flows into the first outdoor heat exchanger through the flow switching device. The refrigerant after heat exchange from the indoor condenser merges with the refrigerant after heat exchange from the first outdoor heat exchanger, and enters the indoor evaporator through the first throttling device. The refrigerant after heat exchange from the indoor evaporator flows back to the compressor.

[0035] The indoor condenser and the first outdoor heat exchanger are both used as condensers, the indoor evaporator is used as an evaporator, and the first outdoor heat exchanger exchanges heat with the external environment to discharge excess heat in the drying room, thereby stabilizing the temperature in the drying room. At the same time, the first outdoor heat exchanger with a smaller heat exchange area avoids the accumulation of more refrigerant, thereby improving the operating reliability of the unit.

[0036] In some embodiments of the present application, the flow path switching device is a four-way valve having a C end, a D end, an S end, and an E end;

[0037] When the four-way valve is powered off, the C end is connected to the D end, and the S end is connected to the E end; when the four-way valve is powered on, the C end is connected to the S end, and the D end is connected to the E end;

[0038] The D end is connected to one end of the indoor condenser connected to the exhaust port of the compressor, the E end is connected to one end of the outdoor heat exchanger not connected to the second throttling device, and the C end and the S end are respectively connected to the suction port of the compressor;

[0039] In the heating and drying mode, the rapid heating and dehumidification mode and the heating and dehumidification mode, the four-way valve is powered off;

[0040] In the steady-temperature dehumidification mode, the four-way valve is powered on.

[0041] By switching the refrigerant flow path through the flow switching device, the outdoor heat exchanger can be used as an evaporator or condenser, thereby meeting multi-mode control requirements.

[0042] In some embodiments of the present application, the on-off integrated drying machine further comprises:

[0043] A capillary tube is connected between the C end and the suction port of the compressor.

[0044] A capillary tube is provided, which has a large resistance, to prevent the refrigerant flowing back to the compressor from entering the four-way valve and accumulating in the four-way valve, causing the four-way valve to fail to operate normally.

[0045] In some embodiments of the present application, the on-off integrated drying machine further comprises:

[0046] The gas-liquid separator has a gas inlet connected to one end of the indoor evaporator not connected to the first throttling device, the S end and one end of the capillary tube, the other end of the capillary tube is connected to the C end, and the gas outlet of the gas-liquid separator is connected to the air intake port of the compressor.

[0047] In some embodiments of the present application, the on-off integrated drying machine further comprises:

[0048] The liquid storage device is connected to the main refrigerant pipeline and receives the refrigerant after heat exchange in the indoor condenser.

[0049] The liquid receiver can be a high-pressure liquid receiver to buffer the refrigerant pressure from the indoor condenser.

[0050] In some embodiments of the present application, the on-off valve is a solenoid valve, which is easy to control. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 The system principle diagram of the existing on-off integrated dryer is shown, wherein the refrigerant flow direction when the dryer is in the heating and temperature raising mode is shown;

[0052] Figure 2 The system principle diagram of the existing on-off integrated dryer is shown, wherein the refrigerant flow direction of the dryer in the steady temperature dehumidification mode is shown;

[0053] Figure 3 An application layout form of an existing open-close integrated drying machine embodiment is shown;

[0054] Figure 4 A system principle diagram of an open-close integrated dryer according to some embodiments is shown, wherein the refrigerant flow direction when the dryer is in a heating and temperature raising mode is shown;

[0055] Figure 5 The schematic diagram of the opening and closing integrated dryer according to some embodiments is shown. Figure 1 , wherein the dryer is in a heating and temperature raising mode;

[0056] Figure 6 A system principle diagram of an open-close integrated dryer according to some embodiments is shown, wherein the refrigerant flow direction of the dryer in a rapid heating and dehumidification mode is shown;

[0057] Figure 7 The schematic diagram of the opening and closing integrated dryer according to some embodiments is shown. Figure 2 , where the dryer is in a rapid heating and dehumidification mode;

[0058] Figure 8 A system principle diagram of an open-close integrated dryer according to some embodiments is shown, wherein the refrigerant flow direction of the dryer in a heating and dehumidification mode is shown;

[0059] Fig. 9 The schematic diagram of the opening and closing integrated dryer according to some embodiments is shown. Figure 3 , where the dryer is in a heating and dehumidification mode;

[0060] Fig.10 A system principle diagram of an open-close integrated dryer according to some embodiments is shown, wherein the refrigerant flow direction of the dryer in a steady-temperature dehumidification mode is shown;

[0061] Fig.11 The schematic diagram of the opening and closing integrated dryer according to some embodiments is shown. Figure 4 , where the dryer is in a steady temperature dehumidification mode;

[0062] Fig.12 A flow chart of an open and close integrated dryer entering a heating temperature rise mode, a rapid temperature rise and dehumidification mode, a temperature rise and dehumidification mode, and a steady temperature and dehumidification mode according to some embodiments is shown.

[0063] Reference numerals:

[0064] 110-indoor condenser; 120-indoor evaporator; 110'-indoor circulation fan; 130-first throttling device; 140-outdoor heat exchanger; 140'-outdoor circulation fan; 141-first outdoor heat exchanger; 142-second outdoor heat exchanger; 150-second throttling device; 160-compressor; 170-four-way valve; 180-check valve; 180'-solenoid valve; 190-capillary tube;

[0065] F1-internal fan; B-gas-liquid separator; B'-liquid storage tank;

[0066] 210-drying room; 220-inlet; 230-exit;

[0067] OA1-air inlet; OA2-air outlet; OA3-fresh air inlet; OA4-exhaust outlet. DETAILED DESCRIPTION

[0068] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0069] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0070] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0071] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0072] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0073] The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplicity and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides various specific examples of processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0074] The heat pump drying method is used to dry items (such as tea leaves) in a drying room. The present application relates to an integrated open and close dryer, which is used to heat and dry, increase temperature and dehumidify, and dehumidify at a stable temperature in the drying room in a heat pump drying room to meet the drying needs in different stages.

[0075] [Heat pump system]

[0076] See also Figures 1 to 3 As described above, the heat pump system in the dryer includes a compressor 160 connected by a refrigerant pipeline, an indoor condenser 110, an indoor evaporator 120, an outdoor heat exchanger 140, a four-way valve 170, a first throttling device 130 and a second throttling device 150.

[0077] The indoor condenser 110 is provided with an indoor circulation fan 110 ′ correspondingly, and the outdoor heat exchanger 140 is provided with an outdoor circulation fan 140 ′ correspondingly.

[0078] The four-way valve 170 is used to switch the refrigerant flow path in different modes so that the outdoor heat exchanger 140 can be used as an evaporator or a condenser.

[0079] One end of the first throttling device 130 is connected to the indoor condenser 110 pipeline, and the other end is connected to the indoor evaporator 120 pipeline, that is, the first throttling device 130 and the indoor evaporator 120 are connected in series to form a first branch.

[0080] One end of the indoor evaporator 120 that is not connected to the first throttling device 130 is respectively connected to the S end of the four-way valve 170 and the air intake port of the compressor 160.

[0081] One end of the second throttling device 150 is connected to the indoor condenser 110 pipeline, and the other end is connected to the outdoor heat exchanger 140 pipeline, that is, the second throttling device 150 and the outdoor heat exchanger 140 are connected in series to form a second branch.

[0082] The end of the outdoor heat exchanger 140 that is not connected to the second throttling device 150 is connected to the E end of the four-way valve 170 .

[0083] One end of the indoor condenser 110 connected to the exhaust port of the compressor 160 is also connected to the D end of the four-way valve 170 , and the C end of the four-way valve 170 is connected to the intake port of the compressor 160 .

[0084] A gas-liquid separator B is designed at the air intake end of the compressor 160 to store the liquid portion of the refrigerant returned to the compressor 160 to prevent the liquid refrigerant from entering the compressor 160 .

[0085] That is, before the refrigerant flows back to the compressor 160 , it first passes through the gas-liquid separator B and then flows back to the air intake port of the compressor 160 .

[0086] The working principle of the heat pump system is as follows: after the high-temperature and high-pressure gaseous refrigerant comes out of the compressor, it releases heat through the condenser and becomes a low-temperature and high-pressure liquid refrigerant. After passing through the throttling device, it becomes a low-temperature and low-pressure liquid refrigerant. It then flows through the evaporator to absorb heat and becomes a low-temperature and low-pressure gaseous refrigerant. After passing through the gas-liquid separator, it flows back to the compressor for compression and enters the next cycle.

[0087] See also Figure 1 When the first throttling device 130 is opened, the second throttling device 150 is opened, and the four-way valve 170 is de-energized, the refrigerant flow path (see Figure 1 The flow direction of the arrow in the middle is: compressor 160->indoor condenser 110, and the refrigerant exchanged from the indoor condenser 110 is divided into two parts.

[0088] A portion of the refrigerant->the first throttling device 130->the indoor evaporator 120->the gas-liquid separator B->the compressor 160.

[0089] Another part of the refrigerant->the second throttling device 150->the outdoor heat exchanger 140->the E end and the S end of the four-way valve 170->the gas-liquid separator B->the compressor 160.

[0090] At this time, the indoor condenser 110 functions as a condenser, and both the indoor evaporator 120 and the outdoor heat exchanger 140 function as evaporators.

[0091] See also Figure 2 When the first throttling device 130 is opened, the second throttling device 150 is opened and the four-way valve 170 is powered on, the refrigerant flow path (see Figure 2 The refrigerant discharged from the compressor 160 is divided into two parts.

[0092] Part of the refrigerant—>indoor condenser 110.

[0093] A portion of the refrigerant->D end and E end of the four-way valve 170->outdoor heat exchanger 140->second throttling device 150.

[0094] The refrigerant after heat exchange from the indoor condenser 110 and the refrigerant after throttling by the second throttling device 150 -> the first throttling device 130 -> the indoor evaporator 120 -> the gas-liquid separator B -> the indoor compressor 160 .

[0095] At this time, both the indoor condenser 110 and the outdoor heat exchanger 140 function as condensers, and the indoor evaporator 120 functions as an evaporator.

[0096] See also Figure 3 , which shows an application layout of a heat pump system in a dryer.

[0097] The space inside the shell is divided into a first chamber A, a second chamber B and a third chamber C. The first chamber A is provided with an air inlet OA1 and an air outlet OA2, which are respectively connected to the drying chamber 210 of the heat pump drying room in the dryer.

[0098] The air inlet OA1 of the first chamber A is communicated with the outlet 230 of the drying chamber 210 , and the air outlet OA2 is communicated with the inlet 220 of the drying chamber 210 .

[0099] An internal fan F1 is provided in the first chamber A, and is specifically arranged in the first chamber A near the air outlet OA2, for introducing the airflow in the first chamber A from the internal fan F1 into the inlet 220 of the drying chamber 210 through the air outlet OA2.

[0100] The air inlet OA1 of the first chamber A returns the air flowing out of the outlet 230 of the drying chamber 210 .

[0101] An indoor condenser 110 is disposed in the first chamber A. An air inlet side and an air outlet side of the indoor condenser 110 are communicated with an air inlet OA1 and an air outlet OA2 of the first chamber A, respectively.

[0102] The air inlet OA1 is disposed at the bottom of the first chamber A, the air outlet OA2 is disposed at the top of the first chamber A, and the indoor condenser 110 is located below the air outlet OA2, specifically below the indoor fan F1 disposed at the air outlet OA2.

[0103] In this way, an airflow from top to bottom is formed in the drying chamber 210 .

[0104] The airflow flowing in through the air inlet OA1 of the first chamber A passes through the indoor condenser 110 and is driven by the indoor fan F1 to be sent into the drying chamber 210 through the air outlet OA2.

[0105] The indoor evaporator 120 is disposed in the second chamber B.

[0106] The third chamber C is provided with a fresh air inlet OA3 and an air outlet OA4 which are in communication therewith, and the outdoor heat exchanger 140 is located in the third chamber C.

[0107] An exhaust fan F3 is provided at the exhaust port OA4.

[0108] Since the outdoor heat exchanger 140 performs heat exchange with the outside fresh air, and all the introduced outside fresh air performs heat exchange with the outdoor heat exchanger 140, the efficiency of the heat pump system can be improved.

[0109] Still see Figure 3 The heat pump system also includes a sensible heat exchanger V, which includes a first channel and a second channel that are staggered (eg, perpendicular to each other) and are used to separate the first chamber A and the second chamber B.

[0110] The sensible heat exchanger V is obliquely arranged between the first chamber A and the second chamber B, so that one end of the sensible heat exchanger V extends into the first chamber A, and the opposite end of the sensible heat exchanger V opposite to the one end extends into the second chamber B.

[0111] The indoor evaporator 120 is vertically disposed in the second chamber B so that the top end of the indoor evaporator 120 abuts against the sensible heat exchanger 140 and extends into the opposite end of the second chamber B, thereby dividing the second chamber B into a first sub-chamber B1 and a second sub-chamber B2.

[0112] In this way, it can be ensured that the airflow flowing out of the first channel of the sensible heat exchanger 140 will pass through the indoor evaporator 120 and return to the second channel to complete sufficient heat exchange.

[0113] exist Figure 1 In the embodiment, the indoor condenser 110 is used as a condenser to provide heat for the airflow in the drying chamber 210 ; the outdoor heat exchanger 140 is used as an evaporator, and the indoor evaporator 120 is used to dehumidify the airflow in the drying chamber 210 .

[0114] See also Figure 3 , (1) When the internal fan F1 is running, the pressure of the drying chamber 210 rises, forcing the internal air to enter the first chamber A from the outlet 230 of the drying chamber 210 and the air inlet OA1 of the first chamber A.

[0115] As the indoor fan F1 operates, the air enters the first chamber A from the outlet 230 of the drying chamber 210 and flows through the indoor condenser 110 .

[0116] Since the surface temperature of the indoor condenser 110 is very high, the air flowing through it is heated and then sucked and pushed by the internal fan F1, passing through the air outlet OA2 of the first chamber A and the inlet 220 of the drying chamber 210, and returning to the drying chamber 210. When the heated air passes through the material to be dried, the liquid water in the material will evaporate and volatilize, and then enter the interior of the dryer 100 again. Part of the water vapor becomes liquid water and is discharged into the outdoor environment. Through continuous circulation, the material is gradually dried.

[0117] In this mode, since the indoor condenser 110 releases heat in the baking room and the outdoor heat exchanger 140 absorbs heat outside the baking room, a large amount of heat can be provided to the air in the baking room.

[0118] (2) In addition, part of the air entering the first chamber A from the outlet 230 of the drying chamber 210 will also enter the sensible heat exchanger V to generate heat transfer, so that the air is cooled.

[0119] Then, it enters the second chamber B and is cooled after heat exchange through the indoor evaporator 120 which also has a low surface temperature.

[0120] Since the air humidity is very high, the dew point temperature of water vapor is easily reached after cooling, and the water vapor in the air becomes condensed water adsorbed on the indoor evaporator 120, and the condensed water can be discharged into the external environment to achieve airflow dehumidification.

[0121] Afterwards, the airflow passes through the sensible heat exchanger V again through the second channel of the sensible heat exchanger V, and after coming out of the sensible heat exchanger V, it finally reaches the indoor condenser 110 .

[0122] In this way, the dehumidified airflow will be heated by the indoor condenser 110, and then attracted and pushed by the internal fan F1, through the air outlet OA2 of the first chamber A and the inlet 220 of the drying chamber 210, and return to the drying chamber 210.

[0123] therefore, Figure 1 Suitable for heating and drying the drying chamber 210 .

[0124] exist Figure 2 In the embodiment, the indoor condenser 110 and the outdoor heat exchanger 140 both function as condensers, and the indoor evaporator 120 functions as an evaporator.

[0125] As mentioned above, at this time Figure 1 The difference is that the outdoor heat exchanger 140 is used as a condenser, so that the unit can discharge excess heat from the drying chamber 210 through the outdoor heat exchanger 140 while heating and dehumidifying, thereby achieving the purpose of stable temperature and dehumidification in the drying chamber.

[0126] However, the refrigerant flowing into the outdoor heat exchanger 140 will quickly condense into liquid in the outdoor heat exchanger due to the large temperature difference between the drying room and the outside, and the flow rate and flow resistance will increase, resulting in a decrease in the amount of refrigerant in the system and unreliable system operation.

[0127] Therefore, the on-off integrated dryer 100 disclosed in the present application divides the outdoor heat exchanger into a first outdoor heat exchanger 141 and a second outdoor heat exchanger 142, and is designed with an on-off valve and a one-way valve 180, so as to ensure the refrigerant circulation amount in the system and improve the system operation reliability by limiting the amount of refrigerant entering the outdoor heat exchanger 140 in the steady temperature dehumidification mode.

[0128] In some embodiments of the present application, compared to Figure 1 and Figure 2 The heat exchange area S of the outdoor heat exchanger 140, the heat exchange area S1 of the first outdoor heat exchanger 141 and the heat exchange area S2 of the second outdoor heat exchanger 142 are each smaller than the heat exchange area S.

[0129] In this way, when the dryer enters the steady temperature dehumidification mode, only the first outdoor heat exchanger 141 or the second outdoor heat exchanger 142 is used as a condenser to avoid excessive refrigerant accumulation in the condenser, thereby solving the problem of unreliable system operation in the existing steady temperature dehumidification mode.

[0130] In some embodiments of the present application, the processing unit (not shown) realizes the heating and drying mode, rapid heating and dehumidification mode, heating and dehumidification mode and stable temperature dehumidification mode of the dryer by controlling the first throttling device 130, the second throttling device 150, the flow switching device and the opening and closing valve.

[0131] In the present application, the flow path switching device is a four-way valve 170 , which can switch the refrigerant flow path so that the outdoor heat exchanger 140 (the first outdoor heat exchanger 141 / the second outdoor heat exchanger 142 ) functions as an evaporator / condenser.

[0132] The four-way valve 170 has a C end, a D end, an E end, and an S end.

[0133] The four-way valve 170 has two states: powered on and powered off.

[0134] When the four-way valve 170 is powered off, the C end is connected to the D end, and the E end is connected to the S end; when the four-way valve 170 is powered on, the C end is connected to the S end, and the E end is connected to the D end.

[0135] In some embodiments of the present application, the on-off valve may be selected as a solenoid valve 180 ′ having two open and closed positions, or other valve bodies having open and closed positions may be selected.

[0136] In some embodiments of the present application, one end of the second throttling device 150 is respectively connected to a position between one end of the first throttling device 130 and the refrigerant discharge end of the indoor condenser 110 (i.e., the end of the indoor condenser 110 that is not connected to the exhaust port of the compressor 160), and the other end of the second throttling device 150 is respectively connected to one end of the first outdoor heat exchanger 141 and one end of the solenoid valve 180'.

[0137] The other end of the solenoid valve 180 ′ is connected to one end of the second outdoor heat exchanger 142 .

[0138] The inlet end of the one-way valve 180 is connected to the other end of the second outdoor heat exchanger 142 , and the outlet end is respectively connected to a position between the other end of the first outdoor heat exchanger 141 and the E end of the four-way valve 170 .

[0139] The one-way valve 180 is used to guide the refrigerant flowing out of the second outdoor heat exchanger 142 out, but cannot guide the refrigerant back to the second outdoor heat exchanger 142 .

[0140] [Heat drying mode]

[0141] In the heating and drying mode, the first throttling device 130 is closed (ie, opened), the second throttling device 150 is opened, the solenoid valve 180 ′ is opened, and the four-way valve 170 is de-energized.

[0142] See also Figure 4 and Figure 5 , Figure 4 and Figure 5 The direction of the arrow in the middle shows the flow direction of the refrigerant, and the dotted line part is the part where the refrigerant does not flow.

[0143] in, Figure 4 The heat pump system in Figure 3 The layout shown is different in that the outdoor heat exchanger 140 is divided into a first outdoor heat exchanger 141 and a second outdoor heat exchanger 142 .

[0144] See also Figure 4 , the four-way valve 170 is de-energized, D and C are connected and E and S are connected, and the compressor 160 compresses the low-temperature and low-pressure refrigerant into a high-temperature and high-pressure state and enters the indoor condenser 110.

[0145] After heat exchange inside the indoor condenser 110, it condenses and releases heat to become liquid refrigerant. Then the refrigerant is throttled to a low-temperature and low-pressure gas-liquid state through the second throttling device 150. The two-phase refrigerant enters the first outdoor heat exchanger 141 and passes through the solenoid valve 180' into the second outdoor heat exchanger 142 to evaporate and absorb heat and become gaseous.

[0146] The refrigerant coming out of the first outdoor heat exchanger 141 and the refrigerant coming out of the second outdoor heat exchanger 142 and passing through the one-way valve 180 enter the gas-liquid separator B through E and S of the four-way valve 170, and are finally sucked into the compressor 160 for compression.

[0147] At this time, the indoor condenser 110 is used as a condenser, the first outdoor heat exchanger 141 and the second outdoor heat exchanger 142 (ie, the outdoor heat exchanger 140 ) are both used as evaporators, and the indoor evaporator 120 is not put into use.

[0148] This mode is suitable for the initial stage of drying room heating. The indoor condenser 110 is used to heat the airflow in the drying room. All outdoor heat exchangers 140 are used to participate in the circulation to increase heat exchange with the external environment, thereby improving the heating effect of the heat pump system.

[0149] Therefore, in this mode, the temperature of the drying chamber begins to rise gradually.

[0150] [Rapid heating and dehumidification mode]

[0151] In the heating and drying mode described above, as the temperature in the drying chamber gradually rises and the air passes through the material to be dried, the liquid water in the material will evaporate and volatilize, and then re-enter the interior of the dryer. Therefore, the airflow needs to be dehumidified at this time.

[0152] Therefore, in the rapid heating and dehumidification mode, the first throttling device 130 is opened, the second throttling device 150 is opened, the solenoid valve 180 ′ is opened, and the four-way valve 170 is de-energized.

[0153] See also Figure 6 and Figure 7 , Figure 6 and Figure 7 The arrow in the middle shows the refrigerant flow direction.

[0154] in, Figure 6 The heat pump system in Figure 3 The layout shown is different in that the outdoor heat exchanger 140 is divided into a first outdoor heat exchanger 141 and a second outdoor heat exchanger 142 .

[0155] See also Figure 6 , the four-way valve 170 is de-energized, D and C are connected and E and S are connected, and the compressor 160 compresses the low-temperature and low-pressure refrigerant into a high-temperature and high-pressure state and enters the indoor condenser 110.

[0156] After heat exchange inside the indoor condenser 110, condensation and heat release occur to become liquid refrigerant, which is then divided into two parts.

[0157] A portion of the refrigerant is throttled to a low-temperature and low-pressure gas-liquid two-phase state through the first throttling device 130 , and the two-phase refrigerant enters the indoor evaporator 120 .

[0158] The other part of the refrigerant is throttled to low-temperature and low-pressure gas-liquid state by the second throttling device 150 and then divided into two parts. One part enters the first outdoor heat exchanger 141 to evaporate and absorb heat, and the other part passes through the solenoid valve 180' to enter the second outdoor heat exchanger 142 to evaporate and absorb heat and become gaseous.

[0159] The refrigerant coming out of the indoor evaporator 120 enters the gas-liquid separator B and is finally sucked into the compressor 160 for compression.

[0160] The refrigerant coming out of the first outdoor heat exchanger 141 and the refrigerant coming out of the second outdoor heat exchanger 142 and passing through the one-way valve 180 enter the gas-liquid separator B through E and S of the four-way valve 170, and are finally sucked into the compressor 160 for compression.

[0161] At this time, the indoor condenser 110 functions as a condenser, the first outdoor heat exchanger 141 and the second outdoor heat exchanger 142 (ie, the outdoor heat exchanger 140 ) both function as evaporators, and the indoor evaporator 120 also functions as an evaporator.

[0162] In this mode, the indoor condenser 110 is used to heat the dry indoor air flow, and all the outdoor heat exchangers 140 are used to participate in the circulation to increase the heat exchange with the external environment, thereby improving the heating effect of the heat pump system.

[0163] At the same time, the indoor evaporator 120 is used as an evaporator to dehumidify the air flow in the drying room.

[0164] Therefore, in this mode, while the temperature in the drying chamber rises significantly, the airflow can also be defrosted to achieve a rapid heating and dehumidification mode.

[0165] [Heating and dehumidifying mode]

[0166] After the rapid heating and dehumidification mode as described above, after the temperature in the drying chamber rises to a certain temperature, it is not desired that the temperature rise so quickly, therefore, the heating and dehumidification mode is entered.

[0167] In the heating and dehumidification mode, the first throttling device 130 is opened, the second throttling device 150 is closed (ie, disconnected), the solenoid valve 180 ′ is disconnected, and the four-way valve 170 is de-energized.

[0168] See also Figure 8 and Fig. 9 , Figure 8 and Fig. 9 The direction of the arrow in the middle shows the flow direction of the refrigerant, and the part shown by the dotted line does not flow through the refrigerant.

[0169] in, Figure 8 The heat pump system in Figure 3 The layout shown is different in that the outdoor heat exchanger 140 is divided into a first outdoor heat exchanger 141 and a second outdoor heat exchanger 142 .

[0170] See also Figure 8 , the four-way valve 170 is de-energized, D and C are connected and E and S are connected, and the compressor 160 compresses the low-temperature and low-pressure refrigerant into a high-temperature and high-pressure state and enters the indoor condenser 110.

[0171] After heat exchange inside the indoor condenser 110, it condenses and releases heat to become liquid refrigerant. The refrigerant is then throttled to a low-temperature and low-pressure gas-liquid state through the first throttling device 130. The two-phase refrigerant enters the indoor evaporator 120, evaporates and absorbs heat, and becomes gaseous.

[0172] The refrigerant coming out of the indoor evaporator 120 enters the gas-liquid separator B and is finally sucked into the compressor 160 for compression.

[0173] At this time, the indoor condenser 110 functions as a condenser, and the indoor evaporator 120 also functions as an evaporator.

[0174] In this mode, the indoor condenser 110 is used to heat the airflow in the drying room, and the indoor evaporator 120 is used as an evaporator to dehumidify the airflow in the drying room.

[0175] Since the indoor condenser 110 and the indoor evaporator 120 are both located inside the drying room and do not exchange heat with the external airflow, the heating efficiency is low and the temperature in the drying room will gradually rise.

[0176] Therefore, in this mode, while the temperature in the drying chamber gradually rises, the airflow can also be defrosted to achieve a heating and dehumidification mode.

[0177] [Steady temperature dehumidification mode]

[0178] After the temperature rise dehumidification mode as described above, after the temperature in the drying chamber rises to a certain temperature, it is hoped that the temperature will be maintained, so the constant temperature dehumidification mode is entered.

[0179] In the steady-temperature dehumidification mode, the first throttling device 130 is opened, the second throttling device 150 is opened, the solenoid valve 180 ′ is disconnected, and the four-way valve 170 is powered on.

[0180] See also Fig.10 and Fig.11 , Fig.10 and Fig.11 The direction of the arrow in the middle shows the flow direction of the refrigerant, and the part shown by the dotted line does not flow through the refrigerant.

[0181] in, Fig.10 The heat pump system in Figure 3 The layout shown is different in that the outdoor heat exchanger 140 is divided into a first outdoor heat exchanger 141 and a second outdoor heat exchanger 142 .

[0182] See also Fig.10 , the four-way valve 170 is powered on, connecting D and E and connecting C and S, and the compressor 160 compresses the low-temperature and low-pressure refrigerant into a high-temperature and high-pressure state, which is divided into two parts.

[0183] A portion of it enters the indoor condenser 110, where it undergoes internal heat exchange, condenses and releases heat to become liquid refrigerant.

[0184] The other part passes through the D and E ends of the four-way valve 170 and enters the first outdoor heat exchanger 141 for internal heat exchange, where it condenses and releases heat to become liquid refrigerant. The refrigerant then passes through the second throttling device 150 and is throttled to a low-temperature and low-pressure gas-liquid state.

[0185] The two-phase refrigerant merges with the refrigerant after heat exchange in the indoor condenser 110, and after throttling by the second throttling device 150, enters the indoor evaporator 120 to evaporate and absorb heat, and becomes gaseous.

[0186] The refrigerant coming out of the indoor evaporator 120 enters the gas-liquid separator B and is finally sucked into the compressor 160 for compression.

[0187] At this time, the indoor condenser 110 and the first indoor heat exchanger 141 both function as condensers, and the indoor evaporator 120 functions as an evaporator.

[0188] In this mode, the indoor condenser 110 is used to heat the airflow in the drying room, and the indoor evaporator 120 is used as an evaporator to dehumidify the airflow in the drying room.

[0189] The first outdoor heat exchanger 141 can exchange heat with the external airflow to discharge the excess heat in the drying room out of the drying room, thereby achieving the purpose of stabilizing the temperature in the drying room.

[0190] compared to Figure 2 , in this application Fig.10 In the embodiment, the refrigerant only flows through the heat exchange area S1 of the first outdoor heat exchanger 141. Therefore, compared with Figure 2 The heat exchange area S of the middle outdoor heat exchanger 140 is relatively small, so the amount of refrigerant accumulated in the first outdoor heat exchanger 141 becomes much smaller, thereby ensuring a sufficient amount of refrigerant circulation inside the system.

[0191] [Calculation of heat exchange area]

[0192] In some embodiments of the present application, in order to avoid excessive refrigerant accumulation in the outdoor heat exchanger 140 in the steady temperature dehumidification mode while ensuring the control requirements of other modes of the dryer, it is necessary to consider designing the heat exchange area S1 of the first indoor heat exchanger 141 and the heat exchange area S2 of the second outdoor heat exchanger 142.

[0193] Taking into account that there can be sufficient refrigerant circulation in the steady temperature dehumidification mode to ensure the normal operation of the unit, it is necessary to control the proportion of liquid refrigerant stored in the first outdoor heat exchanger 141 when it acts as a condenser. In some embodiments of the present application, the ratio of the heat exchange area S1 of the first outdoor heat exchanger 141 to the heat exchange area of ​​the indoor condenser 110 is designed to be between 0.2 and 0.5.

[0194] When designing the heat exchange area S1 of the first outdoor heat exchanger 141, it is also necessary to ensure that in the heating and drying mode and the rapid heating and dehumidification mode, the outdoor heat exchanger 140 (including the first outdoor heat exchanger 141 and the second outdoor heat exchanger 142) can absorb sufficient heat from the external environment when acting as an evaporator to ensure that the heating of the unit can meet the rapid heating and drying requirements.

[0195] Therefore, the ratio of the heat exchange area S2 of the second outdoor heat exchanger 142 to the heat exchange area of ​​the indoor evaporator 120 is designed to be between 0.2 and 1.

[0196] As follows, calculation of the heat exchange area of ​​the first outdoor heat exchanger 141 and the heat exchange area of ​​the second outdoor heat exchanger 142 will be described.

[0197] Generally, during the heating process of the dryer, the heating amount Q=Q 压 +Q 潜 , where Q 压 The input power to the compressor 160 generates heat, Q 潜 The condensed water recovered during the closed operation of the dryer is the latent heat released by the condensation of water vapor into condensed water. At the same time, the circulating air vapor in the heat pump drying room absorbs heat and evaporates the heat of the material, so it can be approximately considered that Q 潜 It is equal to the heat required for the evaporation of moisture in the material.

[0198] Therefore, in the steady-temperature dehumidification mode, the heat that needs to be discharged from the drying chamber is substantially equal to or less than the compressor input heat.

[0199] The heating of the indoor condenser 110 is Q, and the energy efficiency of a general air source heat pump is between 2 and 4.

[0200] Therefore, in the steady temperature dehumidification mode, the heat that the first outdoor heat exchanger 141 needs to release to the external environment is less than Q 压 , where Q 压 The ratio to Q is between 1 / 4 and 1 / 2.

[0201] Since it is necessary to consider that the actual discharged heat needs to be deducted from the heat dissipated in the heat pump baking room and the heat absorbed by the materials, in fact, the ratio of the heat exchange area of ​​the first outdoor heat exchanger 141 to the heat exchange area of ​​the indoor condenser 110 is selected between 0.2 and 0.5.

[0202] In the fast heating and dehumidification mode (see Figure 6 ) under the condition that the first outdoor heat exchanger 141 and the second outdoor heat exchanger 142 are both used as evaporators, and refrigerant flows through to absorb heat from the external environment.

[0203] In order to ensure that the unit can absorb enough heat from the external environment and ensure that the indoor temperature of the heat pump drying room can quickly rise to the set temperature requirement, the sum of the heat exchanger areas of the first outdoor heat exchanger 141 and the second outdoor heat exchanger 142 needs to be greater than the heat exchange area of ​​the indoor evaporator 120.

[0204] Considering that the heat exchange area S of the indoor evaporator 120 蒸 Heat exchange area S with indoor condenser 110 冷 The ratio (i.e., S 蒸 / S 冷 ) is generally between 0.8 and 1.1, and the sum of the heat exchange area S1 of the first outdoor heat exchanger 141 and the heat exchange area S2 of the second outdoor heat exchanger 142 is equal to the heat exchange area S of the indoor evaporator 120. 蒸 The ratio of (S1+S2) / S 蒸 ) experience value is between 1 and 1.3.

[0205] Referring again to the heat exchange area S1 of the first outdoor heat exchanger 141 and the heat exchange area S 冷 ratio (i.e., S1 / S 冷 ) is between 0.2 and 0.5.

[0206] Therefore, the heat exchange area S2 of the second outdoor heat exchanger 142 and the heat exchange area S of the indoor evaporator 120 can be calculated as follows: 蒸 ratio (i.e., S2 / S 蒸 )for.

[0207] Due to S 蒸 / S 冷 =0.8~1.1, S1 / S 冷 =0.2~0.5, (S1+S2) / S 蒸 =1~1.3, so we get:

[0208] S 蒸 =(0.8~1.1)*S 冷 , S1=(0.2~0.5)*S 冷 , (S1+S2) / S 蒸 =1~1.3.

[0209] Therefore, S1+S2=(1~1.3)*S 蒸 , that is, (0.2~0.5)*S 冷 +S2=(1~1.3)*S 蒸 .

[0210] Therefore, S2=(1~1.3)*S 蒸 -(0.2~0.5)*S 冷 (1)

[0211] According to S 蒸 =(0.8~1.1)*S 冷 , that is, S 冷 =S 蒸 / (0.8~1.1) (2)

[0212] Substituting (2) into (1) we obtain:

[0213] S2=(1~1.3)*S 蒸 -(0.2~0.5)*S 蒸 / (0.8~1.1)

[0214] =(1~1.3)*S 蒸 -(0.2 / 1.1~0.5 / 0.8)*S 蒸

[0215] = (1~1.3)*S 蒸 -(0.18~0.625)*S 蒸 (0.375~1.12)*S 蒸 (3)

[0216] In this way, the heat exchange area S2 of the second outdoor heat exchanger 142 and the heat exchange area S 蒸 Ratio.

[0217] Considering the cost and other factors, it is generally required that the heat exchange area of ​​the second outdoor heat exchanger 142 is equal to the heat exchange area S of the indoor evaporator 120. 蒸 The ratio is designed to be between 0.2 and 1.

[0218] In some embodiments of the present application, the heating and drying mode of the dryer as described above is switched by controlling the dry-bulb temperature and the wet-bulb temperature in the drying chamber (see Figure 4 ), fast heating and dehumidification mode (see Figure 6 ), heating and dehumidification mode (see Figure 8 ) and constant temperature dehumidification mode (see Fig.10 ).

[0219] As follows, see Fig.12 , describing the switching flow chart of multiple modes.

[0220] In order to achieve the control requirements, the following parameters are required: a set dry-bulb temperature Tdry_set, a set wet-bulb temperature Twet_set, an actual dry-bulb temperature Tdry in the drying chamber 210, and an actual wet-bulb temperature Twet.

[0221] Calculate the dry-bulb temperature difference △Tdry=Tdry-Tdry_set; the wet-bulb temperature difference △Twet=Twet-Twet_set.

[0222] The operating mode of the dryer is determined based on the dry-bulb temperature difference △Tdry and the wet-bulb temperature difference △Twet.

[0223] When the dry-bulb temperature difference ΔTdry reaches below the first dry-bulb temperature threshold and the wet-bulb temperature difference ΔTwet reaches below the first wet-bulb temperature threshold, the processing unit (not shown) is configured to control the dryer to enter the heating and drying mode.

[0224] When the dry bulb temperature difference ΔTdry reaches above the first dry bulb temperature threshold and below the second dry bulb temperature threshold, and the wet bulb temperature difference ΔTwet reaches below the first wet bulb temperature threshold, the processing unit is configured to control the compressor to stop and only keep the indoor fan 110' turned on.

[0225] When the dry-bulb temperature difference ΔTdry reaches above the second dry-bulb temperature threshold and the wet-bulb temperature difference ΔTwet reaches below the first wet-bulb temperature threshold, the processing unit is configured to control the compressor to stop and only keep the indoor fan 110 ′ turned on.

[0226] When the dry-bulb temperature difference ΔTdry reaches below the first dry-bulb temperature threshold and the wet-bulb temperature difference ΔTwet reaches above the first wet-bulb temperature threshold, the processing unit is configured to control the dryer to enter a rapid heating and dehumidification mode.

[0227] When the dry-bulb temperature difference ΔTdry reaches above the first dry-bulb temperature threshold and below the second dry-bulb temperature threshold, and the wet-bulb temperature difference ΔTwet reaches above the first wet-bulb temperature threshold and below the second wet-bulb temperature threshold, the processing unit is configured to control the compressor to stop and only keep the indoor fan 110' turned on.

[0228] When the dry bulb temperature difference ΔTdry reaches above the second dry bulb temperature threshold and the wet bulb temperature difference ΔTwet reaches above the first wet bulb temperature threshold and below the second wet bulb temperature threshold, the processing unit is configured to control the compressor to stop and only keep the indoor fan 110' turned on.

[0229] When the dry-bulb temperature difference ΔTdry reaches above the first dry-bulb temperature threshold and below the second dry-bulb temperature threshold, and the wet-bulb temperature difference ΔTwet reaches above the second wet-bulb temperature threshold, the processing unit is configured to control the dryer to enter a heating and dehumidification mode.

[0230] When the dry-bulb temperature difference ΔTdry reaches above the second dry-bulb temperature threshold and the wet-bulb temperature difference ΔTwet reaches above the second wet-bulb temperature threshold, the processing unit is configured to control the dryer to enter a steady-temperature dehumidification mode.

[0231] The first dry-bulb temperature threshold is smaller than the second dry-bulb temperature threshold, and the first wet-bulb temperature threshold is smaller than the second wet-bulb temperature threshold.

[0232] The first dry-bulb temperature threshold may be set to a°C, and the second dry-bulb temperature threshold may be set to b°C, where a<b.

[0233] The first wet-bulb temperature threshold may be set to c° C., and the second wet-bulb temperature threshold may be set to d° C., where c<d.

[0234] See also Fig.12 , when △Tdry<a℃ and △Twet<c℃, both the dry bulb temperature and the wet bulb temperature are low, and the heating and drying mode is executed.

[0235] When △Tdry<a℃ and c℃≤△Twet≤d℃, the dry-bulb temperature is low and the wet-bulb temperature begins to increase. Therefore, dehumidification is added while the temperature is rising rapidly, and the rapid heating and dehumidification mode is executed.

[0236] When ΔTdry<a℃ and ΔTwet>d℃, the rapid heating and dehumidification mode is executed.

[0237] When a°C≤ΔTdry≤b°C and ΔTwet<c°C, the compressor stops running and only the indoor fan 110' remains turned on.

[0238] When a°C≤△Tdry≤b°C and c°C≤△Twet≤d°C, the compressor stops running and only the indoor fan 110' remains turned on.

[0239] When a℃≤△Tdry≤b℃ and △Twet>d℃, the dry-bulb temperature is medium and the dry-bulb humidity is high, and the heating and dehumidification mode is executed.

[0240] When ΔTdry>b℃ and ΔTwet<c℃, the compressor stops running and only the indoor fan 110' remains turned on.

[0241] When ΔTdry>b°C and c°C≤ΔTwet≤d°C, the compressor stops running and only the indoor fan 110' remains turned on.

[0242] When △Tdry>b℃ and △Twet>d℃, the dry bulb temperature and wet bulb temperature are both high, and it is necessary to dissipate heat and dehumidify, and implement the steady temperature dehumidification mode.

[0243] In this way, by switching the dryer's various operating modes, the dry-bulb temperature control accuracy and wet-bulb temperature control accuracy requirements in the drying chamber can be met.

[0244] See also Figure 4 , Figure 6 , Figure 8 and Fig.10To ensure the reliable operation of the heat pump system, the heat pump system also includes a pressure buffer device.

[0245] The pressure buffer device is arranged between one end of the indoor condenser not connected to the exhaust port of the compressor 160 and one end of the first throttling device 130 and the second throttling device respectively connected to the indoor condenser 110, and is used to buffer the refrigerant pressure of the refrigerant flowing out of the indoor condenser 110.

[0246] In some embodiments of the present application, the pressure buffer device is a liquid reservoir B'.

[0247] In addition, a capillary tube 190 is connected between the C end of the four-way valve 170 and the air intake port of the compressor 160 (see Figure 4 ).

[0248] The gas inlet of the gas-liquid separator B is respectively connected to one end of the indoor evaporator 120 not connected to the first throttling device 130, the S end and one end of the capillary 190, the other end of the capillary 190 is connected to the C end, and the gas outlet of the gas-liquid separator B is connected to the air intake of the compressor 160.

[0249] The capillary tube 190 is provided to have a large resistance therein, so as to prevent the refrigerant flowing back to the compressor 160 from entering the four-way valve 170 and accumulating in the four-way valve 170, thereby causing the four-way valve 170 to fail to operate normally.

[0250] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in a suitable manner in any one or more embodiments or examples.

[0251] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An integrated open and close dryer, comprising: A heat pump system, comprising a compressor, a flow path switching device, an indoor condenser, an indoor evaporator, an outdoor heat exchanger, a first throttling device and a second throttling device connected by a refrigerant pipeline; The refrigerant after heat exchange in the indoor condenser flows into the indoor evaporator through the first throttling device, and flows into the outdoor heat exchanger through the second throttling device; the flow path switching device is used to switch the refrigerant flow path so that the outdoor heat exchanger serves as the condenser and evaporator; it is characterized in that, The outdoor heat exchanger includes a first outdoor heat exchanger and a second outdoor heat exchanger connected in parallel; the first outdoor heat exchanger and the second outdoor heat exchanger are respectively connected to an on-off valve between the two ends of one side of the second throttling device and a one-way valve between the two ends of the other side, for unidirectionally leading out the refrigerant from the second outdoor heat exchanger; the on-off integrated dryer also includes: a processing unit configured to control the dryer to enter a heating and drying mode, a rapid heating and dehumidification mode, a heating and dehumidification mode, and a steady temperature and dehumidification mode according to a dry-bulb temperature difference between a dry-bulb temperature in the drying chamber and a set dry-bulb temperature, and a wet-bulb temperature difference between a wet-bulb temperature in the drying chamber and a set wet-bulb temperature; In the heating and drying mode, the compressor is started, the first throttling device is closed, the on-off valve and the second throttling device are opened, and the flow path switching device switches the flow path so that the outdoor heat exchanger serves as an evaporator; In the rapid heating and dehumidification mode, the compressor is started, the first throttling device, the second throttling device and the on-off valve are turned on, and the flow path switching device switches the flow path so that the outdoor heat exchanger acts as an evaporator; In the heating and dehumidification mode, the compressor is started, the second throttling device is closed, and the first throttling device is opened; In the steady-temperature dehumidification mode, the compressor is started, the on-off valve is closed, the first throttling device and the second throttling device are opened, and the flow path switching device switches the flow path so that the first outdoor heat exchanger serves as a condenser.

2. The opening and closing integrated drying machine according to claim 1, characterized in that: The ratio of the heat exchange area of ​​the first outdoor heat exchanger to the indoor condenser is in the range of 0.2 to 0.5, which is used to control the amount of refrigerant entering the first outdoor heat exchanger in the steady temperature dehumidification mode; The ratio of the heat exchange area of ​​the second outdoor heat exchanger to the indoor evaporator is in the range of 0.2 to 1, which is used to control the amount of heat absorbed by the second outdoor heat exchanger from the external environment in the heating and drying mode and the rapid heating and dehumidification mode.

3. The opening and closing integrated drying machine according to claim 1, characterized in that: According to the dry-bulb temperature difference and the wet-bulb temperature difference, the dryer is controlled to enter a heating and drying mode, a rapid heating and dehumidification mode, a heating and dehumidification mode, and a steady temperature and dehumidification mode, specifically: When the dry-bulb temperature difference reaches below a first dry-bulb temperature threshold, and the wet-bulb temperature difference reaches below a first wet-bulb temperature threshold, controlling the dryer to enter a heating and drying mode; When the dry-bulb temperature difference reaches above the first dry-bulb temperature threshold and reaches below the second dry-bulb temperature threshold, or reaches above the second dry-bulb temperature threshold and the wet-bulb temperature difference reaches below the first wet-bulb temperature threshold, the compressor stops and only the indoor fan is kept turned on; When the dry-bulb temperature difference reaches below a first dry-bulb temperature threshold and the wet-bulb temperature difference reaches above a first wet-bulb temperature threshold, controlling the dryer to enter a rapid heating and dehumidification mode; When the dry-bulb temperature difference reaches above the first dry-bulb temperature threshold and below the second dry-bulb temperature threshold, or reaches above the second dry-bulb temperature threshold, and the wet-bulb temperature difference reaches above the first wet-bulb temperature threshold and below the second wet-bulb temperature threshold, the compressor stops, and only the indoor fan remains turned on; When the dry-bulb temperature difference reaches above the first dry-bulb temperature threshold and below the second dry-bulb temperature threshold, and the wet-bulb temperature difference reaches above the second wet-bulb temperature threshold, controlling the dryer to enter a heating and dehumidification mode; When the dry-bulb temperature difference reaches above a second dry-bulb temperature threshold, and the wet-bulb temperature difference reaches above a second wet-bulb temperature threshold, controlling the dryer to enter a steady-temperature dehumidification mode; The first dry-bulb temperature threshold is smaller than the second dry-bulb temperature threshold, and the first wet-bulb temperature threshold is smaller than the second wet-bulb temperature threshold.

4. The opening and closing integrated drying machine according to claim 3, characterized in that: In the heating and drying mode, the refrigerant discharged from the compressor flows out after passing through the indoor condenser for heat exchange, flows into the outdoor heat exchanger for heat exchange after being throttled by the second throttling device, and flows back to the compressor through the flow path switching device; In the rapid heating and dehumidification mode, the refrigerant discharged from the compressor flows out after passing through the indoor condenser for heat exchange, a part of the refrigerant flows into the indoor evaporator through the first throttling device, and a part of the refrigerant flows into the outdoor heat exchanger through the second throttling device, and the refrigerant after heat exchange from the indoor evaporator merges with the refrigerant flowing out from the outdoor heat exchanger through the flow path switching device and flows back to the compressor; In the heating and dehumidification mode, the refrigerant discharged from the compressor flows out after passing through the indoor condenser for heat exchange, and the refrigerant flowing out flows into the indoor evaporator for heat exchange after being throttled by the first throttling device, and the refrigerant after heat exchange flows back to the compressor; In the steady temperature dehumidification mode, a part of the refrigerant discharged from the compressor enters the indoor condenser for heat exchange, and a part of the refrigerant flows into the first outdoor heat exchanger through the flow switching device. The refrigerant after heat exchange from the indoor condenser merges with the refrigerant after heat exchange from the first outdoor heat exchanger, and enters the indoor evaporator through the first throttling device. The refrigerant after heat exchange from the indoor evaporator flows back to the compressor.

5. The opening and closing integrated drying machine according to claim 4, characterized in that: The flow path switching device is a four-way valve having a C end, a D end, an S end and an E end; When the four-way valve is powered off, the C end is connected to the D end, and the S end is connected to the E end; when the four-way valve is powered on, the C end is connected to the S end, and the D end is connected to the E end; The D end is connected to one end of the indoor condenser connected to the exhaust port of the compressor, the E end is connected to one end of the outdoor heat exchanger not connected to the second throttling device, and the C end and the S end are respectively connected to the suction port of the compressor; In the heating and drying mode, the rapid heating and dehumidification mode and the heating and dehumidification mode, the four-way valve is powered off; In the steady-temperature dehumidification mode, the four-way valve is powered on.

6. The opening and closing integrated drying machine according to claim 5, characterized in that: Also includes: A capillary tube is connected between the C end and the suction port of the compressor.

7. The integrated open and close drying machine according to claim 6, characterized in that: Also includes: The gas-liquid separator has a gas inlet connected to one end of the indoor evaporator not connected to the first throttling device, the S end and one end of the capillary tube, respectively; the other end of the capillary tube is connected to the C end; and the gas outlet of the gas-liquid separator is connected to the air intake port of the compressor.

8. The opening and closing integrated drying machine according to claim 1, characterized in that: Also includes: The liquid storage device is connected to the main refrigerant pipeline and receives the refrigerant after heat exchange in the indoor condenser.

9. The opening and closing integrated drying machine according to claim 1, characterized in that: The on-off valve is a solenoid valve.

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