阅读说明：本技术 一种模块化换向通风干燥机的余热回收装置及方法 (Waste heat recovery device and method of modular reversing ventilation dryer ) 是由 魏海 谢焕雄 颜建春 吴惠昌 王建楠 刘敏基 高学梅 张会娟 于 2020-06-19 设计创作，主要内容包括：本发明涉及农作物干燥领域的一种模块化换向通风干燥机的余热回收装置及方法,在干燥机箱体内湿度很大时,下连通管组、箱体下风口、箱体内腔、箱体上风口、上连通管组、余热回收管组上进气端依次接通,形成从下往上的干燥气流,在干燥机箱体内湿度减小时,上连通管组、箱体上风口、箱体内腔、箱体下风口、下连通管组、余热回收管组下进气端依次接通,形成从上往下的干燥气流；湿度较大时,余热回收管组的排湿风阀打开并进行排湿,减小热泵冷凝器的工作负荷,湿度较小时,排湿风阀关闭,废热空气进入热泵冷凝器与新鲜空气进行热交换,完成废热回收,从而达到能量利用率高、热能损耗显著减小的目的。(The invention relates to a waste heat recovery device and a method of a modularized reversing ventilation dryer in the field of crop drying.A lower communicating pipe group, a lower box air inlet, a box inner cavity, an upper box air inlet, an upper communicating pipe group and an upper waste heat recovery pipe group are sequentially communicated when the humidity in a box body of the dryer is very high to form drying air flow from bottom to top; when the humidity is higher, the dehumidifying air valve of the waste heat recovery pipe group is opened and dehumidifies, the work load of the heat pump condenser is reduced, when the humidity is lower, the dehumidifying air valve is closed, waste heat air enters the heat pump condenser to exchange heat with fresh air, waste heat recovery is completed, and therefore the purposes of high energy utilization rate and remarkable reduction of heat energy loss are achieved.)

1. The utility model provides a waste heat recovery device of modularization switching-over ventilation drying machine which characterized in that: the heat pump system comprises a heat pump host (1), an induced draft tube set and a fan (5) which are sequentially communicated, and further comprises a waste heat recovery tube set, a heat pump condenser (29), a heat pump evaporator (30) and an electric control system;

an air inlet duct tee joint (7) is communicated with the air outlet side of the fan (5), air is fed into one port of the air inlet duct tee joint (7), air is fed out from the other two ports of the air inlet duct tee joint (7), and is respectively connected with a lower communicating pipe group and an upper communicating pipe group, and is respectively connected with a box body lower air inlet (31) and a box body upper air inlet (32) through the lower communicating pipe group and the upper communicating pipe group, the upper communicating pipe group is positioned above the lower communicating pipe group, and the lower communicating pipe group and the upper communicating pipe group are respectively provided with a lower air inlet duct air valve (8) and an upper air inlet duct air valve (13);

the waste heat recovery pipe group is provided with a lower air inlet end and an upper air inlet end, and is respectively laterally connected with the lower communicating pipe group and the upper communicating pipe group, and the upper air inlet end and the lower air inlet end of the waste heat recovery pipe group are respectively provided with an upper air return duct air valve (16) and a lower air return duct air valve (19);

when a lower air inlet duct air valve (8) and an upper air return duct air valve (16) are opened and an upper air inlet duct air valve (13) and a lower air return duct air valve (19) are closed, the lower communicating pipe group, a box body lower air inlet (31), a box body inner cavity, a box body upper air inlet (32), an upper communicating pipe group and an upper air inlet end of a waste heat recovery pipe group are sequentially communicated;

when the lower air inlet duct air valve (8) and the upper air return duct air valve (16) are closed and the upper air inlet duct air valve (13) and the lower air return duct air valve (19) are opened, the upper communicating pipe group, the box body upper air inlet (32), the box body inner cavity, the box body lower air inlet (31), the lower communicating pipe group and the lower air inlet end of the waste heat recovery pipe group are sequentially communicated;

the waste heat recovery pipe set is provided with a temperature sensor and a humidity sensor which are in signal connection with an electric control system, the waste heat recovery pipe set is provided with a moisture exhaust air valve (25) which is opened when the humidity is greater than a preset value and is closed when the humidity is less than the preset value, the waste heat recovery pipe set is also provided with a heat recovery air valve (27) which is closed when the humidity is greater than the preset value and is opened when the humidity is less than the preset value, the moisture exhaust air valve (25) and the heat recovery air valve (27) are sequentially arranged according to the airflow direction, and the air outlet end of the waste heat recovery pipe set is connected with a heat pump condenser (29) and is connected with the heat pump condenser (29) when the heat;

the heat pump condenser (29) is installed on the heat pump host (1), the heat release side of the heat pump condenser (29) is in thermal contact with a heat exchanger arranged at the fresh air inlet end of the heat pump host (1), and the heat pump evaporator (30) is arranged at the fresh air inlet end of the heat pump host (1);

the heat pump host (1), the fan (5), the lower air inlet duct air valve (8), the upper air inlet duct air valve (13), the upper air return duct air valve (16), the lower air return duct air valve (19), the moisture exhaust air valve (25) and the heat recovery air valve (27) are all controlled by an electric control system.

2. The waste heat recovery device of the modular reversing ventilation dryer of claim 1, characterized in that:

the lower communicating pipe group comprises a lower air duct tee joint (9) and a lower box body connecting port (10);

the upper communicating pipe group comprises an upper side lower air duct connecting pipe (11), an upper air duct right-angle elbow (12), an upper air duct tee joint (14) and an upper box body connecting port (15);

the waste heat recovery pipe group comprises a front air return channel tee joint (18), and the front air return channel tee joint (18) is provided with an upper air inlet end, a lower air inlet end and a backward air outlet end;

one end of the lower air duct tee joint (9) is butted with one air outlet end of the air inlet duct tee joint (7), a lower air inlet duct air valve (8) is arranged, the other end of the lower air duct tee joint (9) is communicated with a box body lower air inlet (31) through a lower box body connecting port (10), the side part of the lower air duct tee joint (9) is connected with a lower air inlet end of the front air return duct tee joint (18), and a lower air return duct air valve (19) is arranged at the connecting position of the lower air duct tee joint and the lower air inlet end;

another air-out end of air inlet duct tee bend (7) up to loop through upside down wind channel connecting pipe (11), go up wind channel right angle return bend (12) and be connected with the one end of last wind channel tee bend (14), the one end that goes up wind channel tee bend (14) and last wind channel right angle return bend (12) are connected sets up last wind channel air valve (13), the other end of going up wind channel tee bend (14) is put through with box upper air inlet (32) through last box connector (15), the last inlet end of preceding return air duct tee bend (18) is connected to the lateral part of going up wind channel tee bend (14) and sets up return air duct air valve (16) at junction between them.

3. The waste heat recovery device of the modular reversing ventilation dryer of claim 2, characterized in that: the upper air inlet end and the lower air inlet end of the front air return duct tee joint (18) are respectively provided with an upper air return duct right-angle elbow (17) and a lower air return duct right-angle elbow (20) which are arched outwards.

4. The waste heat recovery device of the modular reversing ventilation dryer of claim 2, characterized in that: the waste heat recovery pipe group comprises a return air pipeline (21), a rear return air duct right-angle elbow (22), a rear return air duct tee joint (23), a heat recovery air duct right-angle elbow (26) and a heat recovery bell mouth (28), wherein the air outlet end of the front return air duct tee joint (18) is communicated with one side of the rear return air duct tee joint (23) sequentially through the return air pipeline (21) and the rear return air duct right-angle elbow (22), the other side of the rear return air duct tee joint (23) is communicated with one side of the heat recovery air duct right-angle elbow (26), the other side of the heat recovery air duct right-angle elbow (26) is connected with one side of the heat recovery bell mouth (28), and a heat recovery air valve (27) is arranged at; and the moisture exhaust air valve (25) is arranged at the upper end of the back air return channel tee joint (23).

5. The heat recovery device of the modular reversing ventilation dryer of claim 4, characterized in that: the upper end of the back air return channel tee joint (23) is provided with a moisture exhaust port right-angle elbow (24), and the moisture exhaust air valve (25) is arranged on one side of the moisture exhaust port right-angle elbow (24) back to the heat pump host (1).

6. The waste heat recovery device of the modular reversing ventilation dryer of claim 1, characterized in that: the induced draft nest of tubes includes air inlet connecting pipe (2), air inlet tee bend (3) and two air intake (4), air inlet tee bend (3) have an air inlet end and two air-out ends, the air inlet end of air inlet tee bend (3) is put through with heat pump host computer (1) through air inlet connecting pipe (2), the two air-out ends of air inlet tee bend (3) are put through with the air inlet end of fan (5) through two air intake (4) respectively.

7. The waste heat recovery device of the modular reversing ventilation dryer of claim 1, characterized in that: the air outlet end of the fan (5) is communicated with a hot air trapezoid port (6) and is communicated with the air inlet end of the air inlet channel tee joint (7) through the hot air trapezoid port (6).

8. A waste heat recovery method of a modular reversing ventilation dryer is characterized by comprising the following steps:

A1. when the materials are wet:

firstly, fresh air enters a heat pump host (1) through a heat pump evaporator (30) to be heated, hot air enters an air inlet duct tee joint (7) through a fan (5), at the moment, a lower air inlet duct air valve (8) is opened, meanwhile, a lower air return duct air valve (19) is closed, and the hot air enters a box body lower air inlet (31) of the dryer after passing through a lower air duct tee joint (9) and a lower box body connecting port (10); hot air passes through the material layer from bottom to top through the lower air passage and then enters the upper air passage of the box body, waste gas enters the upper air passage tee joint (14) through the upper air inlet (32) of the box body, the upper air inlet air valve (13) is closed at the moment, the upper air return passage air valve (16) is opened, the waste gas enters the rear air return passage tee joint (23) after passing through the front air return passage tee joint (18), the air return pipeline (21) and the rear air return passage right-angle elbow (22), the moisture exhaust air valve (25) at the top of the rear air return passage tee joint (23) is opened to exhaust high-humidity waste gas, the heat recovery air valve (27) is closed at the same time, and no waste gas enters the heat recovery horn; when the humidity of the waste gas exceeds a preset value, the humidity exhaust air valve (25) is driven to be opened, the heat recovery air valve (27) is driven to be closed, and the high-humidity waste gas is exhausted;

then, when the material in the dryer box body forms a moisture gradient, the flow direction of the drying air flow is automatically switched, at the moment, the upper air inlet duct air valve (13) is opened, the upper air return duct air valve (16) is closed, and hot air enters the box body air inlet (32) of the dryer through the upper air duct tee joint (14) and the upper box body connecting port (15); hot air passes through the material layer from top to bottom through the lower air duct and then enters the lower air duct of the box body; the wet and hot air enters a lower box body connecting port (10) and a lower air duct tee joint (9) through a box body lower air inlet (31), at the moment, a lower air inlet duct air valve (8) is closed, a lower air return duct air valve (19) is opened, the wet and hot air enters a rear air return duct tee joint (23) through a front air return duct tee joint (18), an air return pipeline (21) and a rear air return duct right-angle bent pipe (22), at the moment, a moisture exhaust air valve (25) at the top of the rear air return duct tee joint (23) is opened, a heat recovery air valve (27) is closed, and a pipeline leading to a heat pump condenser (29) is continuously in a closed state;

A2. dry material to slightly low moisture:

if the humidity in the box body is lower than the set humidity, the humidity exhaust air valve (25) is closed, the heat recovery air valve (27) is opened, waste heat air enters the heat pump condenser (29) through the heat recovery air channel right-angle elbow (26) and the heat recovery bell mouth (28), the heat pump condenser (29) cools and liquefies the waste heat air and releases heat outwards, the heat heats fresh air through a heat exchanger in the heat pump host (1), waste gas is discharged from an outlet at the top end of the heat pump host (1), the fresh air heated by the heat exchanger passes through the heat pump evaporator (30) and is reheated according to the set temperature for drying or is directly used for drying materials;

if the humidity in the box body rises to the set humidity, the humidity exhaust air valve (25) is opened, the heat recovery air valve (27) is closed, no waste gas is led to the heat pump condenser (29) temporarily, and waste heat air with higher humidity is directly exhausted;

the two substeps of the step A2 are alternately carried out according to the humidity value change of the return air pipeline (21) until the materials in the box body of the dryer are in low moisture;

A3. when the material is dried to a low moisture content:

when the materials are dried to be low in moisture, the humidity of waste heat air is kept at a set value, at the moment, waste gas enters the rear air return channel tee joint (23) through the air return pipeline (21), the moisture exhaust air valve (25) is closed, the heat recovery air valve (27) is opened, and the waste heat air enters the heat pump condenser (29) to exchange heat with fresh air, so that waste heat recovery is completed.

Technical Field

The invention relates to the field of crop drying, in particular to a waste heat recovery device and a waste heat recovery method of a modularized reversing ventilation dryer.

Background

With the gradual improvement of the mechanization degree of grain and oil crops in recent years, the grain and oil crops after being harvested are influenced by factors in various aspects such as fields, weather and the like, the grain and oil crops with high moisture content can not be dried effectively in time, and are easy to mildew in different degrees, thereby bringing serious economic loss to vast farmers. As an economical and practical grain and oil crop dryer, the modularized box type dryer is high in automation degree, can be modularly combined according to actual harvest quantity, is flexible in configuration, reasonable in structure and convenient and fast to operate, and can meet the requirements of farmers with different planting scales. Through adjusting drying equipment operating parameter, can also dry different agricultural products, equipment has stronger commonality, avoids equipment idle, and the investment recovery period is short, and market prospect is can be good.

At present, there are a lot of insufficiencies in current box drying equipment: in order to reduce the equipment cost, the equipment is dried by adopting a fixed ventilation mode, the ventilation uniformity cannot be ensured, and a drying dead angle exists in the drying process; the temperature rise difference of the stacked material layers is large, and the material precipitation rates are inconsistent; the drying sequence mostly adopts a fixed type (from bottom to top), and because of the influence of the thickness of the material layer, the drying of the material on the upper layer is lagged, which is not beneficial to the uniform drying; because waste heat recovery is difficult, the equipment mostly adopts a direct discharge type, waste heat can not be recovered in the drying process, the energy utilization rate is low, and the waste is serious.

The adopted up-down reversing ventilation drying technology designs a modularized reversing ventilation dryer which is granted by a patent with the patent number of 201711224634.5. The modular reversing ventilation dryer comprises a drying tunnel formed by splicing at least two drying chamber modules, wherein each drying chamber module is formed by hinging a bottom air duct with an open top surface and one side of a chamber body with a screen at the bottom surface, and one end of the drying tunnel is provided with a lower air inlet and an upper air inlet which are respectively communicated with the bottom air duct and the upper part of the chamber body; the bottom surface of the bottom air channel and the top surface of the chamber body are respectively provided with air guide mechanisms which are distributed at intervals along the air supply direction, the modularized reversing ventilation dryer can be used for feeding air from the lower air channel at the bottom of the box body and returning air from the upper air channel of the box body and returning air from the lower air channel at the upper part of the box body, so that the drying air supply direction can be changed as appropriate, thereby avoiding the phenomenon that the bottom material is excessively dried and the top material is insufficiently dried, meanwhile, the air guide mechanisms which are distributed at intervals along the air supply direction are respectively arranged on the bottom surface of the bottom air channel and the top surface of the chamber body, and the air guide mechanisms can be adjusted to be small at the angle close to an air supply port and large at the angle far away from the air supply port, so that the wind field in the length direction of the whole drying channel is uniformly distributed, thereby solving the problems of overlarge, the drying quality is ensured. The reversing drying technology changes the inherent drying sequence of the materials on the upper layer and the lower layer, and effectively solves the problem of non-uniformity in the thickness direction of the material layers.

However, the conventional drying equipment has problems of low energy utilization rate and serious waste of heat energy (during high-temperature drying) in the later period of operation.

Disclosure of Invention

The invention aims to provide a waste heat recovery device and a waste heat recovery method for a modular reversing ventilation dryer, and aims to solve the problems of low later-stage energy utilization rate and serious heat energy waste (during high-temperature drying) in the operation of the conventional drying equipment.

The purpose of the invention is realized as follows: a waste heat recovery device of a modularized reversing ventilation dryer comprises a heat pump host, an induced draft tube set and a fan which are sequentially communicated, and further comprises a waste heat recovery tube set, a heat pump condenser, a heat pump evaporator and an electric control system;

an air inlet duct tee joint is communicated with the air outlet side of the fan, air is fed from one port of the air inlet duct tee joint, air is discharged from the other two ports of the air inlet duct tee joint, and is respectively connected with a lower communicating pipe group and an upper communicating pipe group, and is respectively connected with a box body lower air inlet and a box body upper air inlet through the lower communicating pipe group and the upper communicating pipe group, the upper communicating pipe group is positioned above the lower communicating pipe group, and the lower communicating pipe group and the upper communicating pipe group are respectively provided with a lower air inlet duct air valve and an upper air inlet duct air valve;

the waste heat recovery pipe group is provided with a lower air inlet end and an upper air inlet end, and is respectively laterally connected with the lower communicating pipe group and the upper communicating pipe group, and the upper air inlet end and the lower air inlet end of the waste heat recovery pipe group are respectively provided with an upper air return duct air valve and a lower air return duct air valve;

when the lower air inlet duct air valve and the upper air return duct air valve are opened and the upper air inlet duct air valve and the lower air return duct air valve are closed, the upper air inlet ends of the lower communicating pipe group, the box body lower air inlet, the box body inner cavity, the box body upper air inlet, the upper communicating pipe group and the waste heat recovery pipe group are sequentially communicated;

when the lower air inlet duct air valve and the upper air return duct air valve are closed and the upper air inlet duct air valve and the lower air return duct air valve are opened, the upper communicating pipe group, the box body upper air inlet, the box body inner cavity, the box body lower air inlet, the lower communicating pipe group and the lower air inlet end of the waste heat recovery pipe group are sequentially communicated;

the waste heat recovery pipe set is provided with a temperature sensor and a humidity sensor which are in signal connection with an electric control system, the waste heat recovery pipe set is provided with a moisture exhaust air valve which is opened when the humidity is greater than a preset value and is closed when the humidity is less than the preset value, the waste heat recovery pipe set is also provided with a heat recovery air valve which is closed when the humidity is greater than the preset value and is opened when the humidity is less than the preset value, the moisture exhaust air valve and the heat recovery air valve are sequentially arranged according to the airflow direction, and the air outlet end of the waste heat recovery pipe set is connected with a heat pump condenser and is connected with the heat pump condenser when the heat recovery air;

the heat pump condenser is arranged on the heat pump main machine, the heat release side of the heat pump condenser is in thermal contact with a heat exchanger arranged at the fresh air inlet end of the heat pump main machine, and the heat pump evaporator is arranged at the fresh air inlet end of the heat pump main machine;

the heat pump host, the fan, the lower air inlet duct air valve, the upper air return duct air valve, the lower air return duct air valve, the moisture exhaust air valve and the heat recovery air valve are all controlled by an electric control system.

Further, the lower communicating pipe set comprises a lower air duct tee joint and a lower box body connecting port;

the upper communicating pipe group comprises an upper side lower air duct connecting pipe, an upper air duct right-angle elbow, an upper air duct tee joint and an upper box body connecting port;

the waste heat recovery pipe group comprises a front air return channel tee joint, and the front air return channel tee joint is provided with an upper air inlet end, a lower air inlet end and a backward air outlet end;

one end of the lower air duct tee joint is butted with one air outlet end of the air inlet duct tee joint, a lower air inlet duct air valve is arranged, the other end of the lower air duct tee joint is communicated with a lower air inlet of the box body through a lower box body connecting port, the side part of the lower air duct tee joint is connected with the lower air inlet end of the front air return duct tee joint, and a lower air return duct air valve is arranged at the connecting position of the lower air duct tee joint and the lower air inlet duct air valve;

the three-way air outlet end of air inlet duct is up to loop through upside lower wind channel connecting pipe, last wind channel right angle return bend and be connected with the three-way one end of last wind channel in proper order, the one end that last wind channel tee bend and last wind channel right angle return bend are connected sets up last wind channel air valve, the three-way other end of last wind channel is put through with the box air inlet through last box connector, the three-way last inlet end of preceding return air duct is connected to the three-way lateral part of last wind channel and sets up return air duct air valve in junction between them.

Furthermore, an upper air inlet end and a lower air inlet end of the front air return duct tee joint are respectively provided with an upper air return duct right-angle elbow and a lower air return duct right-angle elbow which are arched outwards.

Further, the waste heat recovery pipe group comprises a return air pipeline, a rear return air duct right-angle elbow, a rear return air duct tee joint, a heat recovery air duct right-angle elbow and a heat recovery bell mouth, wherein the air outlet end of the front return air duct tee joint is communicated with one side of the rear return air duct tee joint through the return air pipeline and the rear return air duct right-angle elbow in sequence, the other side of the rear return air duct tee joint is communicated with one side of the heat recovery air duct right-angle elbow, the other side of the heat recovery air duct right-angle elbow joint is connected with one side of the heat recovery bell mouth, and a heat recovery air valve is arranged at; and the moisture exhaust air valve is arranged at the upper end of the back air return channel tee joint.

Furthermore, the upper end of the back air return channel tee joint is provided with a moisture exhaust port right-angle elbow, and the moisture exhaust air valve is arranged on one side of the moisture exhaust port right-angle elbow, which is back to the heat pump host.

Furthermore, induced draft nest of tubes includes air inlet connecting pipe, air inlet tee bend and two air intakes, the air inlet tee bend has an air inlet end and two air-out ends, the air inlet end of air inlet tee bend is put through with the heat pump host computer through the air inlet connecting pipe, the two air-out ends of air inlet tee bend are put through with the air inlet end of fan through two air intakes respectively.

Furthermore, the air outlet end of the fan is communicated with a hot air trapezoid port, and is communicated with the air inlet port of the air inlet duct tee joint through the hot air trapezoid port.

As another aspect of the present invention, a method for recovering waste heat of a modular reversing ventilation dryer is characterized by comprising the following steps:

A1. when the materials are wet:

firstly, fresh air enters a heat pump host machine through a heat pump evaporator to be heated, hot air enters an air inlet duct tee joint through a fan, at the moment, an air valve of a lower air inlet duct is opened, an air valve of a lower air return duct is closed, and the hot air enters a lower air opening of a box body of the dryer after passing through the lower air duct tee joint and a lower box body connecting port; hot air passes through the material layer from bottom to top through the lower air duct and then enters the upper air duct of the box body, waste gas enters the upper air duct tee joint through the upper air inlet of the box body, the upper air duct air valve is closed at the moment, the upper air return duct air valve is opened, the waste gas enters the rear air return duct tee joint after passing through the front air return duct tee joint, the air return pipeline and the rear air return duct right-angle bent pipe, the moisture exhaust air valve at the top of the rear air return duct tee joint is opened at the moment to exhaust high-humidity waste gas, meanwhile, the heat recovery air valve is closed, and no waste gas enters the heat recovery; when the humidity of the waste gas exceeds a preset value, driving a humidity exhaust air valve to be opened and a heat recovery air valve to be closed, and discharging the high-humidity waste gas;

then, when the material in the box body of the dryer forms a moisture gradient, the flow direction of the drying air flow is automatically switched, at the moment, the air valve of the upper air inlet channel is opened, the air valve of the upper air return channel is closed, and hot air enters the air inlet of the box body of the dryer through the upper air channel tee joint and the upper box body connecting port; hot air passes through the material layer from top to bottom through the lower air duct and then enters the lower air duct of the box body; the wet and hot air enters a lower box body connecting port and a lower air duct tee joint through a box body lower air inlet, at the moment, an air valve of a lower air inlet duct is closed, an air valve of a lower air return duct is opened, the wet and hot air enters a rear air return duct tee joint through a front air return duct tee joint, an air return pipeline and a rear air return duct right-angle bent pipe, at the moment, a moisture exhaust air valve at the top of the rear air return duct tee joint is opened, a heat recovery air valve is closed, and a pipeline leading to a heat pump condenser is continuously in a;

A2. dry material to slightly low moisture:

if the humidity in the box body is lower than the set humidity, the humidity exhaust air valve is closed, the heat recovery air valve is opened, waste heat air enters the heat pump condenser through the heat recovery air duct right-angle elbow and the heat recovery bell mouth, the heat pump condenser cools and liquefies the waste heat air and releases heat outwards, the heat heats fresh air through a heat exchanger in the heat pump host, waste gas is discharged from an outlet at the top end of the heat pump host, and the fresh air heated by the heat exchanger passes through a heat pump evaporator and is reheated according to the set drying temperature or directly used for drying materials;

if the humidity in the box body rises to the set humidity, the humidity exhaust air valve is opened, the heat recovery air valve is closed, no waste gas is led to the heat pump condenser temporarily, and waste heat air with higher humidity is directly exhausted;

the two substeps of the step A2 are alternately carried out according to the humidity value change of the return air pipeline until the materials in the box body of the dryer are in low moisture;

A3. when the material is dried to a low moisture content:

when the materials are dried to low moisture, the humidity of the waste heat air is kept at a set value, at the moment, the waste gas enters the rear air return channel tee joint through the air return pipeline, the moisture exhaust air valve is closed, the heat recovery air valve is opened, so that the waste heat air enters the heat pump condenser to exchange heat with fresh air, and waste heat recovery is completed.

The invention has the beneficial effects that: under the environment that the temperature is comparatively special, this waste heat recovery device can be better improve energy utilization and rate, reduce heat loss to can let the heat pump host computer intake temperature at low temperature obviously improve, increase the intensification range, guarantee that the output temperature of heat pump host computer can reach the default at low temperature, ensure drying quality.

Drawings

Fig. 1 is a first perspective view of the present invention.

Fig. 2 is a second perspective view of the present invention.

Fig. 3 is a third perspective view of the present invention.

Fig. 4 is a fourth perspective view of the present invention.

Fig. 5 is an assembly view of the present invention.

In the figure, 1, a heat pump host; 2. an air inlet connecting pipe; 3. an air inlet tee joint; 4. an air inlet; 5. a fan; 6. a hot air trapezoidal port; 7. an air inlet channel tee joint; 8. a lower air inlet duct blast valve; 9. a lower air duct tee joint; 10. a lower box body connecting port; 11. an upper lower duct connecting pipe; 12. an upper air duct right-angle elbow; 13. an upper air inlet duct air valve; 14. an upper air duct tee joint; 15. an upper tank body connecting port; 16. an upper return duct air valve; 17. an upper return air duct right-angle elbow; 18. a front air return channel tee joint; 19. a lower return duct air valve; 20. a lower return air duct right-angle elbow; 21. a return air line; 22. a right-angle elbow of the rear return air duct; 23. a back air return channel tee joint; 24. a right-angle elbow of the moisture discharging port; 25. a moisture exhaust air valve; 26. a heat recovery air duct right-angle elbow; 27. a heat recovery damper; 28. a heat recovery flare; 29. a heat pump condenser; 30. a heat pump evaporator; 31. a box body lower air opening; 32. and an air inlet of the box body.

Detailed Description

The invention will be further described with reference to the accompanying figures 1-5 and the specific embodiments. The air-out direction that uses fan 5 in this embodiment is preceding, and fan 5 is preceding air-out promptly, and the air return direction is opposite with fan 5's air-out direction in this embodiment, consequently can think the air return direction backward.

Referring to fig. 1-5, a waste heat recovery device of a modular reversing ventilation dryer includes a heat pump host 1, an induced draft tube set, a fan 5, a waste heat recovery tube set, a heat pump condenser 29, a heat pump evaporator 30, and an electric control system, wherein the electric control system may be a PLC control device or other control devices.

An air inlet channel tee joint 7 is communicated with the air outlet side of the fan 5, air is fed from one port of the air inlet channel tee joint 7, air is discharged from the other two ports of the air inlet channel tee joint 7, a lower communicating pipe group and an upper communicating pipe group are respectively connected with a box body lower air inlet 31 and a box body upper air inlet 32 through the lower communicating pipe group and the upper communicating pipe group, the upper communicating pipe group is positioned on the lower communicating pipe group, and a lower air inlet channel air valve 8 and an upper air inlet channel air valve 13 are respectively arranged on the lower communicating pipe group and the upper communicating pipe group.

The waste heat recovery pipe group is provided with a lower air inlet end and an upper air inlet end, and is respectively connected with the lower communicating pipe group and the upper communicating pipe group in a lateral mode, and the upper air inlet end and the lower air inlet end of the waste heat recovery pipe group are respectively provided with an upper air return duct air valve 16 and a lower air return duct air valve 19.

When the lower air inlet duct air valve 8 and the upper air return duct air valve 16 are opened and the upper air inlet duct air valve 13 and the lower air return duct air valve 19 are closed, the upper air inlet ends of the lower communicating pipe group, the box lower air inlet 31, the box inner cavity, the box upper air inlet 32, the upper communicating pipe group and the waste heat recovery pipe group are sequentially communicated.

When the lower air inlet duct air valve 8 and the upper air return duct air valve 16 are closed and the upper air inlet duct air valve 13 and the lower air return duct air valve 19 are opened, the upper communicating pipe group, the box body upper air inlet 32, the box body inner cavity, the box body lower air inlet 31, the lower communicating pipe group and the lower air inlet end of the waste heat recovery pipe group are sequentially communicated.

The waste heat recovery pipe set is provided with a temperature sensor and a humidity sensor which are in signal connection with an electric control system, the waste heat recovery pipe set is provided with a dehumidifying air valve 25 which is opened when the humidity is greater than a preset value and is closed when the humidity is less than the preset value, the waste heat recovery pipe set is further provided with a heat recovery air valve 27 which is closed when the humidity is greater than the preset value and is opened when the humidity is less than the preset value, the dehumidifying air valve 25 and the heat recovery air valve 27 are sequentially arranged according to the air flow direction, and the air outlet end of the waste heat recovery pipe set is connected with a heat pump condenser 29 and is connected with the heat pump condenser 29 when the heat recovery.

The heat pump condenser 29 is mounted on the heat pump main unit 1, a heat releasing side of the heat pump condenser 29 thermally contacts a heat exchanger provided at a fresh air inlet end of the heat pump main unit 1, and the heat pump evaporator 30 is provided at a fresh air inlet end of the heat pump main unit 1.

The heat pump host 1, the fan 5, the lower air inlet duct air valve 8, the upper air inlet duct air valve 13, the upper air return duct air valve 16, the lower air return duct air valve 19, the moisture exhaust air valve 25 and the heat recovery air valve 27 are all controlled by an electric control system.

The lower communicating pipe set comprises a lower air duct tee joint 9 and a lower box body connecting port 10.

The upper communicating pipe group comprises an upper side lower air duct connecting pipe 11, an upper air duct right-angle elbow 12, an upper air duct tee joint 14 and an upper box body connecting port 15.

The waste heat recovery pipe group comprises a front air return channel tee joint 18, and the front air return channel tee joint 18 is provided with an upper air inlet end, a lower air inlet end and an air outlet end which faces backwards.

One end of the lower air duct tee joint 9 is butted with one air outlet end of the air inlet duct tee joint 7, a lower air inlet duct air valve 8 is arranged, the other end of the lower air duct tee joint 9 is communicated with a lower air inlet 31 of the box body through a lower box body connecting port 10, the side part of the lower air duct tee joint 9 is connected with a lower air inlet end of the front air return duct tee joint 18, and a lower air return duct air valve 19 is arranged at the connecting position of the lower air duct tee joint and the front air return duct tee joint.

The other air outlet end of the air inlet channel tee joint 7 faces upwards and sequentially passes through an upper side lower air channel connecting pipe 11 and an upper air channel right-angle bent pipe 12 to be connected with one end of an upper air channel tee joint 14, an upper air inlet channel air valve 13 is arranged at one end of the upper air channel tee joint 14 connected with the upper air channel right-angle bent pipe 12, the other end of the upper air channel tee joint 14 is communicated with an upper air inlet 32 of the box body through an upper box body connecting port 15, the side part of the upper air channel tee joint 14 is connected with the upper air inlet end of a front air return channel tee joint 18, and an upper air return channel air valve 16 is arranged.

The upper air inlet end and the lower air inlet end of the front air return duct tee joint 18 are respectively provided with an upper air return duct right-angle elbow 17 and a lower air return duct right-angle elbow 20 which are arched outwards.

The waste heat recovery pipe group comprises a return air pipeline 21, a rear return air duct right-angle elbow 22, a rear return air duct tee 23, a heat recovery air duct right-angle elbow 26 and a heat recovery bell mouth 28, wherein the air outlet end of the front return air duct tee 18 is communicated with one side of the rear return air duct tee 23 through the return air pipeline 21 and the rear return air duct right-angle elbow 22 in sequence, the other side of the rear return air duct tee 23 is communicated with one side of the heat recovery air duct right-angle elbow 26, the other side of the heat recovery air duct right-angle elbow 26 is connected with one side of the heat recovery bell mouth 28, and a heat recovery air valve 27 is arranged at; the moisture exhaust air valve 25 is arranged at the upper end of the back air return channel tee 23.

The upper end of the back air return channel tee 23 is provided with a moisture exhaust port right-angle elbow 24, and a moisture exhaust air valve 25 is arranged on one side of the moisture exhaust port right-angle elbow 24, which is back to the heat pump host 1.

The induced draft tube group comprises an air inlet connecting tube 2, an air inlet tee joint 3 and two air inlets 4, the air inlet tee joint 3 is provided with an air inlet end and two air outlet ends, the air inlet end of the air inlet tee joint 3 is communicated with the heat pump host 1 through the air inlet connecting tube 2, and the two air outlet ends of the air inlet tee joint 3 are communicated with the air inlet end of the fan 5 through the two air inlets 4 respectively.

The air outlet end of the fan 5 is communicated with a hot air trapezoid port 6 and is communicated with the air inlet end of an air inlet channel tee joint 7 through the hot air trapezoid port 6.

The waste heat recovery method of the modular reversing ventilation dryer comprises the following steps:

A1. when the materials are wet:

firstly, forming air flow from bottom to top by adopting a lower ventilation drying mode, enabling fresh air to enter a heat pump host 1 through a heat pump evaporator 30 for heating, enabling hot air to enter an air inlet duct tee joint 7 through a fan 5, opening a lower air inlet duct air valve 8 at the moment, closing a lower air return duct air valve 19 at the same time, and enabling the hot air to enter a box body lower air inlet 31 of the dryer after passing through a lower air duct tee joint 9 and a lower box body connecting port 10; hot air passes through the material layer from bottom to top through the lower air passage and then enters the upper air passage of the box body, waste gas enters the upper air passage tee joint 14 through the upper air inlet 32 of the box body, the upper air passage air valve 13 is closed at the moment, the upper air return passage air valve 16 is opened, the waste gas enters the rear air return passage tee joint 23 after passing through the front air return passage tee joint 18, the air return pipeline 21 and the rear air return passage right-angle elbow 22, the moisture exhaust air valve 25 at the top of the rear air return passage tee joint 23 is opened at the moment to exhaust high-humidity waste gas, meanwhile, the heat recovery air valve 27 is closed, and no waste gas enters the heat recovery bell; the steps are all operations carried out under the condition that the humidity of the waste gas is high in the early drying period, in the drying process, all air valves of the device are controlled by a controller, temperature and humidity sensors are installed in the waste heat recovery pipe group and can be arranged in the air return pipeline 21, the temperature and the humidity in the waste gas can be monitored at any time, when the humidity of the waste gas exceeds a preset value, the humidity exhaust air valve 25 is driven to be opened, the heat recovery air valve 27 is driven to be closed, the high-humidity waste gas is discharged, and the burden of the heat pump condenser 29 is avoided being increased.

Then, when the materials in the dryer box body form a moisture gradient, automatic reversing is carried out, upper ventilation drying is adopted, and airflow from top to bottom is formed, so that the materials in the dryer box body can be dried more uniformly, at the moment, the upper air inlet duct air valve 13 is opened, the upper air return duct air valve 16 is closed, and hot air enters the box body air inlet 32 of the dryer through the upper air duct tee joint 14 and the upper box body connecting port 15; hot air passes through the material layer from top to bottom through the lower air duct and then enters the lower air duct of the box body; the damp and hot air enters the lower box body connecting port 10 and the lower air duct tee joint 9 through the box body lower air inlet 31, at the moment, the lower air inlet duct air valve 8 is closed, the lower air return duct air valve 19 is opened, the damp and hot air enters the rear air return duct tee joint 23 through the front air return duct tee joint 18, the air return pipeline 21 and the rear air return duct right-angle bent pipe 22, at the moment, the moisture exhaust air valve 25 at the top of the rear air return duct tee joint 23 is opened, the heat recovery air valve 27 is closed, and the pipeline leading to the heat pump condenser 29 is continuously in a closed state.

A2. Dry material to slightly low moisture:

after drying for a period of time, the moisture content of the materials in the dryer box body is reduced, the humidity of the waste gas is reduced, if the humidity in the box body is lower than the set humidity, the humidity exhaust air valve 25 is closed, the heat recovery air valve 27 is opened, so that the waste heat air enters the heat pump condenser 29 through the heat recovery air duct right-angle elbow 26 and the heat recovery bell mouth 28, the heat pump condenser 29 cools and liquefies the waste heat air and releases heat to the outside, the heat heats the fresh air through the heat exchanger in the heat pump host 1, the waste gas is discharged from the outlet at the top end of the heat pump host 1, the fresh air heated by the heat exchanger passes through the heat pump evaporator 30, and the fresh air is reheated by the heat pump host 1.

In the drying process, if the humidity in the box body rises to the set humidity, the humidity exhaust air valve 25 is opened, the heat recovery air valve 27 is closed, no waste gas is led to the heat pump condenser 29 temporarily, and waste heat air with high humidity is directly exhausted.

The two substeps of step a2 alternate according to the variation of the humidity value of the return air line 21 until the material inside the drier tank is at a low moisture content.

A3. When the material is dried to a low moisture content:

when the materials are dried to low moisture, the humidity of the waste heat air is kept at a set value, in order to improve the energy utilization rate, at the moment, the waste gas enters the back air return channel tee joint 23 through the air return pipeline 21, the moisture exhaust air valve 25 is closed, and the heat recovery air valve 27 is opened, so that the waste heat air enters the heat pump condenser 29 to exchange heat with the fresh air, and the waste heat recovery is completed.

While the preferred embodiments of the present invention have been described, those skilled in the art will appreciate that various changes and modifications can be made therein without departing from the spirit and scope of the invention as defined by the appended claims.