CN-122015435-A - Heat pump drying air duct structure and drying control method

CN122015435ACN 122015435 ACN122015435 ACN 122015435ACN-122015435-A

Abstract

The application discloses a heat pump drying air duct structure and a drying control method. The drying chamber is provided with an air outlet, the air channel chamber is provided with a fresh air inlet and an air inlet, the air channel chamber is divided into a fresh air cavity, an air inlet cavity and an air return cavity by a partition plate, the air return cavity and the fresh air cavity form a first channel and a second channel for unidirectional air inlet of the air return cavity to the fresh air cavity, the fresh air cavity and the air inlet cavity form a third channel, the air return cavity and the air inlet cavity form a fourth channel for unidirectional air inlet, the fresh air inlet, the air outlet and the air return inlet are all provided with adjustable leaf valves, an open type, a semi-open type or a closed type circulation channel can be selectively formed by adjusting the leaf valve switch, and the heat pump unit is used for heating air in the air channel chamber. The application provides a novel heat pump drying air duct structure integrating three modes of an open type, a semi-open type and a closed type and a drying control method.

Inventors

ZHENG HUOSHENG
SHEN XIANGYANG
ZHANG ZHANWEN
GAO WANG

Assignees

广东飞瑞科新能源科技有限公司

Dates

Publication Date: 20260512
Application Date: 20260206

Claims (10)

1. A heat pump drying air duct structure is characterized by comprising a drying chamber, an air duct chamber and a heat pump unit, wherein an air outlet is formed in the drying chamber, a fresh air inlet is formed in the air duct chamber, an air return opening and an air inlet are formed between the drying chamber and the air duct chamber, a partition plate is arranged in the air duct chamber, the inner cavity of the air duct chamber is divided into a fresh air chamber, an air inlet chamber and an air return chamber by the partition plate, the air outlet is communicated with the inner cavity of the drying chamber, the fresh air inlet is communicated with the fresh air chamber, the air return opening and the air inlet are respectively communicated with the air return chamber and the air inlet chamber, a first channel and a second channel are formed between the air return chamber and the fresh air chamber, a third channel is formed between the air inlet chamber and the fresh air chamber, a fourth channel is formed between the air return chamber and the air inlet chamber, air enters the fresh air chamber by the air inlet, the heat pump unit is at least used for heating the air in the air duct chamber, the fresh air inlet, the air outlet and the air outlet are respectively provided with an adjustable leaf valve, and an adjustable leaf valve are arranged between the fresh air inlet and the fresh air chamber, the air circulation channel and the air circulation channel are formed by adjusting a leaf valve, or an open circulation channel.
2. The heat pump drying tunnel structure according to claim 1, wherein the heat pump unit includes a first condenser, a second condenser, a dehumidifying and energy recovering assembly and an outdoor evaporator, the first condenser and the second condenser are disposed in an inner cavity of the tunnel chamber and are operated in series for heating a gas in the tunnel chamber, the dehumidifying and energy recovering assembly is disposed in the inner cavity of the tunnel chamber for dehumidifying a gas in a return air chamber and recovering heat, and the outdoor evaporator is disposed outside the drying chamber and the tunnel chamber for absorbing an outside heat source.
3. The heat pump drying tunnel structure according to claim 2, wherein the first condenser is mounted on a partition plate to form the first passage, the dehumidifying and energy recovering assembly is mounted on the partition plate to form the second passage, the second condenser is mounted on the partition plate to form the third passage, a first one-way ventilation valve is further provided on the partition plate, and the first one-way ventilation valve forms the fourth passage.
4. The heat pump drying duct structure according to claim 3, wherein the dehumidifying and energy recovering assembly comprises an indoor evaporator and a cross-flow heat exchanger, the cross-flow heat exchanger comprises an in-plate flow path and an out-plate flow path which exchange heat mutually, the upper end of the out-plate flow path is in one-way communication with the return air cavity, the lower end of the out-plate flow path is communicated with the inlet of the indoor evaporator, the outlet of the indoor evaporator is communicated with the in-plate flow path Cheng Liantong, the fresh air cavity is finally communicated through the in-plate flow path, and the bottom of the indoor evaporator is provided with a condensation drain pipe communicated with the outside.
5. The heat pump drying duct structure according to any one of claims 1 to 4, wherein the open circulation flow channel is formed under the condition that leaf valves at the return air inlet are closed, leaf valves at the fresh air inlet and the exhaust air outlet are opened, and two air flow paths are formed, the first air flow path sequentially passes through the fresh air inlet, the fresh air cavity, the first channel, the return air cavity, the fourth channel, the air inlet cavity, the air inlet and the drying chamber, the second air flow path sequentially passes through the fresh air inlet, the fresh air cavity, the third channel, the air inlet cavity, the air inlet and the drying chamber, and finally is discharged outside the exhaust air outlet.
6. The heat pump drying air duct structure according to any one of claims 1 to 4, wherein the semi-open circulation flow channel is formed under the condition that leaf valves at the fresh air port, the return air port and the air outlet are opened simultaneously to form an exhaust air flow path and a return air flow path, the exhaust air flow path sequentially passes through the fresh air port, the fresh air cavity, the third channel, the air inlet cavity, the air inlet and the drying chamber, part of air is finally discharged out of the air outlet, the other part of air flows back to the air duct chamber from the return air flow path, and the return air flow path sequentially passes through the return air port and the return air cavity, respectively passes through the first channel and the second channel, is collected in the fresh air cavity, and continues to circulate in the drying chamber and the air duct chamber.
7. The heat pump drying duct structure according to any one of claims 1 to 4, wherein the closed circulation flow channel is formed under the condition that leaf valves at the return air inlet are opened, leaf valves at the fresh air inlet and the exhaust air outlet are closed, and the air flow path sequentially passes through the fresh air inlet, the fresh air cavity, the third channel, the air inlet cavity, the air inlet, the drying chamber, the return air inlet and the return air cavity, passes through the first channel and the second channel respectively, and is collected in the fresh air cavity to complete closed circulation.
8. A drying control method of a heat pump drying air duct structure according to any one of claims 1 to 7 is characterized by comprising the following steps of S1, acquiring the precision type of materials to be dried, S2, acquiring water content data of the materials, matching corresponding heating temperature, humidity threshold, temperature difference threshold and reference drying time according to the water content data and the precision type of the materials, S3, selecting an open type, a semi-open type or a closed type drying mode according to the precision type of the materials, adjusting corresponding leaf valves to the open type circulation flow channel, the semi-open type circulation flow channel or the closed type circulation flow channel, starting a heat pump unit to heat gas to a set heating temperature, S4, detecting the difference between the humidity, the drying temperature and the temperature of a condenser in real time and continuously drying time so as to judge whether preset shutdown conditions are met, and S5, continuously operating for a plurality of minutes and then shutting down when the preset shutdown conditions are met.
9. The drying control method according to claim 8, wherein in the open mode and the semi-open mode, the shutdown condition includes that the humidity of the air outlet is less than a humidity threshold and a difference between the temperature of the air outlet and the temperature of the condenser is less than or equal to a temperature difference threshold, and in the closed mode, the shutdown condition includes that the humidity of the air return is less than the humidity threshold and a difference between the temperature of the inner cavity of the drying chamber and the temperature of the condenser is less than or equal to the temperature difference threshold.
10. The drying control method of claim 8, wherein the stop condition further comprises a duration of drying time being greater than or equal to a reference drying time.

Description

Heat pump drying air duct structure and drying control method Technical Field The invention relates to the field of heat pump drying devices, in particular to a heat pump drying air duct structure and a drying control method. Background Along with popularization of energy-saving and environment-friendly concepts and upgrading of multi-scene drying demands of agricultural products, industrial products, daily necessities and the like, the traditional electric heating type dryer is gradually replaced by a heat pump dryer due to the defects of high energy consumption, high risk of material heat damage and the like. The heat pump dryer is based on the reverse Carnot circulation principle, and forms a heat pump drying system through a compressor, an evaporator, a condenser, a throttling device and a circulation air duct, so as to complete a drying process of cooling, dehumidifying and heating circulation, namely, the evaporator condenses and discharges water vapor of air in the system to realize dehumidification, the condenser heats and heats the dehumidified air, the heated dry air contacts with a material to be dried and takes away moisture, and three circulation modes of full return air, partial return air and full fresh air can be realized by combining air duct adjustment, so that continuous and stable drying circulation is formed. Compared with the traditional equipment, the energy consumption of the heat pump dryer can be reduced by 40% -60%, the drying temperature can be stably controlled within a range of 35-60 ℃, the heat damage of heat sensitive materials can be effectively avoided, and the heat pump dryer is widely applicable to drying of materials such as clothes, fruits and vegetables, precise parts and agricultural products and becomes the main stream drying equipment in the current market. In the existing heat pump drying technology, a plurality of devices based on different air duct circulation modes exist, but the devices have obvious functional limitations, and the balance of multi-scene suitability, drying precision and energy utilization efficiency is difficult to consider. For example, patent CN208998443U discloses a top-mounted open type heat pump dryer which has compact structure, convenient installation, rapid discharge of high humidity air through open type circulation, suitability for scenes with lower requirements for drying residual moisture, but can not guarantee stability of drying quality in applications with higher requirements for drying precision and residual moisture control of meat, fruit and the like, patent CN115751928a discloses a closed type heat pump dryer which has the advantages of maximized heat recovery through full closed type circulation, high energy utilization rate and little environmental pollution, but has the problems of waste and the like due to unmatched material values when drying low added value materials such as grains and the like. To solve the defect of single circulation mode, some technologies try to integrate multiple circulation modes, such as patent CN111466594a discloses an air source heat pump pepper dryer, which has three hot air circulation modes of open loop, closed loop and semi-closed loop, but semi-closed loop circulation is not fully disclosed, and the system has no dehumidification and energy recovery component. Disclosure of Invention The invention aims to solve the technical problems and provides a novel heat pump drying air duct structure integrating three modes of an open type, a semi-open type and a closed type and a drying control method. In order to achieve the above purpose, the technical scheme of the invention is as follows: A heat pump drying air duct structure comprises a drying chamber, an air duct chamber and a heat pump unit, wherein an air outlet is formed in the drying chamber, a fresh air inlet is formed in the air duct chamber, an air return opening and an air inlet are formed between the drying chamber and the air duct chamber, a partition plate is arranged in the air duct chamber, the inner cavity of the air duct chamber is divided into a fresh air cavity, an air inlet cavity and an air return cavity by the partition plate, the air outlet is communicated with the inner cavity of the drying chamber, the fresh air inlet is communicated with the fresh air cavity, the air return opening and the air inlet are respectively communicated with the air return cavity and the air inlet cavity, a first channel and a second channel are formed between the air return cavity and the fresh air cavity, a third channel is formed between the air inlet cavity and the fresh air cavity, a fourth channel is formed between the air return cavity and the air inlet cavity, the air return cavity is in a unidirectional air inlet cavity, air enters the fresh air cavity by the air inlet, the heat pump unit is at least used for heating the air in the air duct chamber, the fresh air inlet, the air outlet and the air outlet are respectively provided with